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The Stratigraphy, Foraminifera, And Paleoecology Of The Montesano Formation, Grays Harbor County, Washington

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The Stratigraphy, Foraminifera, And Paleoecology Of The Montesano Formation, Grays Harbor County, Washington

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Content T h is d isser ta tio n h as been 65— 12,258 m icro film ed ex a ctly as r e c e iv e d FOW LER, G erald A llan , 1934- THE STRATIGRAPHY, FORAM INIFERA, AND PALEOECOLOGY OF THE MONTESANO FORMATION, GRAYS HARBOR COUNTY, WASHINGTON. U n iv ersity of Southern C aliforn ia, P h .D ., 1965 G eology University Microfilms, Inc., Ann Arbor, M ichigan THE STRATIGRAPHY, FORAMINIFERA, AND PALEOECOLOGY OF THE MONTESANO FORMATION, GRAYS HARBOR COUNTY, WASHINGTON by Gerald Allan Fowler A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (Geology) June 1965 UNIVERSITY O F S O U T H E R N CALIFORNIA T H E GRA DUATE SC H O O L U N IV ER SITY PA RK LO S A N G E LE S, C A L IFO R N IA S 0 0 0 7 This dissertation, written by ..................... _G e raid. _Allan__Fowle_r....................... under the direction of his.....Dissertation Com mittee, and approved by all its members, has been presented to and accepted by the Graduate School, in partial fulfillment of requirements for the degree of D O C T O R OF P H I L O S O P H Y ......... ‘ ^ Dean Date JuneA ..!.9.65................................... ! TABLE OF CONTENTS i | | Page i 'LIST OF FIGURES................................ vii i LIST OF T A B L E S ..........................................xiii ABSTRACT .............................................. 1 I 'Chapter INTRODUCTION ....................................... 3 I Purpose and Scope ................................. 3 Geographic Setting ............................... 5 Methods ............................................ 8 ! Field w o r k ...................................... 8 ; Laboratory analyses............................. 11 J ; ! Acknowledgments 13 j PREVIOUS WORK....................................... 15 i REGIONAL GEOLOGIC HISTORY .......................... 29 MONTESANO FORMATION ................................. 43 Areal Geology..................................... 43 | Cloquallum area................................. 44 Satsop area..................................... 49 IChapter Page j i ; I | Southern portion 50 , ! < j ! Northern portion 61 i j Wishkah a r e a .................................... 64 j j i : i 1 Southern p o r t i o n .............................. 65 ! i Northern portion ................................ 66 , Summary and conclusions............................ 67 j j i : Physical Stratigraphy 72 ; General orientation.............................. 72 j ; I i Type section.................................... 75 j Reference sections ............................. 104 j | Northern Wishkah area 104 | I i Wishkah River, West F o r k ..................... 104 Wishkah River, East F o r k ..................... 113 ; i Wynoochee River............................... 119 j i Summary...................................... 126 j ; i Northern Satsop a r e a ......................... 132 \ Canyon R i v e r ............................... 133 J ; i ; ! Satsop River, upper West F o r k............. 154! ! Satsop River, upper Middle F o r k............ 164 ! | Satsop River, middle West F o r k ............ 170 i | Summary....................................... 194 phapter Page i [ Cloquallum Creek a r e a......................... 198 Southern Satsop a r e a ......................... 202 Southern Wishkah a r e a......................... 203 Summary and conclusions....................... 204 Age and Correlation................................ 213 Introduction ..................................... 213 Foraminiferal biostratigraphy .................. 216 Planktonic foraminifera ....................... 222 Benthic foraminifera ......................... 227 Faunal comparisons with older and younger units ................................ 237 Astoria Formation ........................... 237 Quinault Formation ......................... 246 Correlation....................................... 252 Washington..................................... 253 O r e g o n ......................................... 253 Northern California ........................... 254 Southern California ........................... 255 Summary and conclusions ......................... 257 Paleoecology ....................................... 265 Introduction .................................... 265 i Chapter | Foraminifera ........... I Species composition . . Wishkah River sections West Fork, Satsop River and Canyon River sections................ Species diversity . . . Foraminiferal number Faunal displacement . . Planktonic foraminifera Arenaceous foraminifera Porcelaneous foraminifera Miscellaneous micro-organisms Radiolaria Statoliths Diatoms Ostracodes Molluscs Terrestrial flora Page i 268 268 | I 273 : 279 288 I 289 ^ i 292 | i 293 ! I i 296 297 I I 298 298 Environmental aspects of the sediment . . . Summary and conclusions .................... 300 302 303 304 308 309 316 v jChapter Page | CONCLUSIONS .......................................... 320 i FAUNAL REFERENCE LISTS ............................. 326 REFERENCES CITED ................................... 346 I LIST OF FIGURES Figure Page 1. Location map of Grays Harbor County and surrounding area, Washington ......... 7 2. Comparison of previous geologic maps of the Montesano Formation with that of this study............................... 19 3. Composite columnar section of Tertiary strata in Grays Harbor Basin ............. 32 4. Geologic sketch map of Grays Harbor Basin . . 34 5. Western Oregon and Washington Early Eocene epieugeosyncline .................... 37 6. Geologic map of the Montesano Formation in Grays Harbor Basin ...................... 46 7. Major outcrop areas of the Montesano Formation.................................... 48 8. Sketch of the basal contact of the Monte sano Formation, SE corner sec. 36, T.19N.,R.7W................................... 54 9. Photograph of part of the contact illus trated in Figure 8 ......................... 56 10. Photograph of a hand specimen displaying part of the contact shown in Figure 8 . . . 58 11. Photograph of a hand specimen of the contact shown in Figure 8 .................. 60 | Figure | 12. 13. 14. 15 • 16. 17 . 18. 19 . 20 . 21. 22 . Page Major structural features developed in the Montesano Formation .................... 7 0 Locations of measured sections .............. 74 Station locations for the Middle Fork, ; Wishkah River section ....................... 79 ; Photograph of the base of the Montesano Formation, Middle Fork, Wishkah River . . . 81i i Sketch of a portion of the basal contact | exposed about 300 feet to the northwest j of W K - 1 ....................................... 84 ] Photograph of a large boring at the contact shown in Figure 1 6 ............................ 87 Photograph of an external mold of Zirfaea (?) sp. at the contact shown in Figure 16 . . . 89 Columnar section of the Montesano Formation, measured along the Middle Fork of the Wishkah River ................................ 91 Photograph of the basal sandstone unit at Station WK-2 on the Middle Fork, Wishkah River......................................... 93 Photograph of a portion of lithologic unit 5 of the lower member of the Montesano Formation at Station WK-20, Middle Fork, Wishkah River ................................ 98 Photograph of a portion of unit 6 of the upper member at Station WK-33, Middle Fork, Wishkah River........................... 101 23. Photograph of unit 7 at Station WK-38, Middle Fork, Wishkah River .... 103 I I I jFigure i I | 24. Station locations for the West Fork, I Wishkah River section ...................... ) 25. Columnar section of the Montesano Formation measured along the West Fork of the Wishkah River ............................... 26. Photograph of the contact between the Montesano and Astoria Formations on the West Fork, Wishkah River . . v ......... 27. Station locations, East Fork, Wishkah River . 28. Columnar section of the Montesano Formation measured along the East Fork of the I Wishkah River ..............' ................ 29. Station locations, Wynoochee River ......... 30. Columnar section of the Montesano Formation measured along the Wynoochee River . . . . 31. Photograph of abundant "worm" burrows in the Montesano Formation at Station WY-16 on the Wynoochee River . . . . . . " ; . . 32. Suggested correlation of sections measured along the West, Middle and East Forks of the Wishkah River and the Wynoochee River . 33. Station locations, Canyon River ............. 34. Columnar section of the Montesano Formation measured along the Canyon River ........... 35. Photograph of the contact between the Montesano and Astoria Formations on the I Canyon River ............................... IX P a g e i 106 , ] j 108 j 111 115 I I I I 117 ; 121 I 1 124 : I i 128 | i I 131 I i 135 ! ! i i 137 | i 140 ^Figure Page 36. Photograph of two hand specimens of the contact shown in Figure 3 5 ................ 142 37. Photograph of a portion of the basal sandstone unit of the Montesano Formation in the Canyon River section................. 145 38. Photograph of the lowest conglomerate bed on the Canyon River........................ 147 39. Photograph of the same bed as shown in Figure 38 exposed in a road cut above ; the Canyon R i v e r ........................... 149 40. Photograph of the sandy mudstone unit on the Canyon River at Station C - 1 3 .......... 153 41. Photograph of a conglomerate lense in the uppermost sandstone unit on the Canyon River........................................ 156 42. Station locations measured along the upper West Fork, Satsop River............... . . 158 43. Columnar section of the Montesano Formation, i upper West Fork, Satsop River .............. 161 44. Station locations, upper Middle Fork, Satsop R i v e r ............................... 166 45. Columnar section of the Montesano Formation measured along the upper Middle Fork, Satsop River ............................... 169 46. Station locations, middle West Fork, Satsop River ............................... 172 47. Columnar section of the Montesano Formation measured along the middle West Fork, Satsop River ...................... 175 Figure 48. 49 . 50. i 51 • 52. 53. I I 54. 55. 56. 57. Photograph of convolute structures at Station MWS-38 on the West Fork of the Satsop River ............................ Photograph of laminated mudstone at Station MWS-14 on the West Fork of the Satsop River ............................ Photograph of a hand specimen from the section illustrated in Figure 49 .... Photograph of thin-bedded to laminated strata at Station MWS-40 on the West Fork of the Satsop River ............... Photograph of a portion of the section illustrated in Figure 51................. Sketch of the filled channel in the vicinity of Station MWS-33, West Fork, Satsop River ............................ Photograph of part of the channel filling illustrated in Figure 53 ............... Suggested correlation of sections measured along the upper parts of the West and Middle Forks, Satsop River and the Canyon River ..................................... Suggested correlation of the Canyon River and middle West Fork, Satsop River sections ................................ Suggested correlation of the Canyon River and the Middle Fork, Wishkah River sections ................................ Page i 179 ! I i | 181 ! 183 ! i I j I 186 j 188 j j 191 i 193 I i j 197 ! 200 j j 211 xi j i 'Figure f 58. Stratigraphic distribution of benthic ; foraminifera, Montesano Formation, Wishkah River ............................... 59. Known ranges through California Miocene and Pliocene Stages of diagnostic benthic foraminifera from the Montesano Formation . 60. Sample location map and tentative composite columnar section for the Astoria Forma tion in Grays Harbor Basin ........ ! 61. Sample location map and tentative columnar section for the Quinault Formation . . . . ! 62. Previous age determinations of the Monte sano Formation ............................ 63. Idealized columnar section illustrating the stratigraphic relationships between the Quinault, Montesano, and Astoria Formations in the Grays Harbor Basin ................. i 64. Distribution of paleoecologic parameters through the Montesano Formation on the Middle Fork, Wishkah River ............... 65. Distribution of paleoecologic parameters through the laminated mudstone unit of the Montesano Formation on the West Fork, Satsop River ............................... 66. Distribution of paleoecologic parameters through the Montesano Formation on the Canyon River ............................... i I Page j I 231 i I I ] 233 j 240 ; 249 ; 259 j I I i 262 ) I 277 j i i I 281 ! i 287 | xii LIST OF TABLES 'Table 1 !• ! 2- I 3 • i 4 . | | 5. I 6 . 7 . 8. I 9 . Comparison of approximate paleobathymetry of formations beneath the Montesano Formation .................................... Relative percentage abundance of foraminifera and other microfossils, Montesano Forma tion, Middle Fork, Wishkah River ......... Relative percentage abundance of foraminifera and other microfossils, Montesano Forma tion ....................................... . Relative percentage abundance of foraminifera and other microfossils, Montesano Forma tion, laminated shale unit, West Fork, Satsop River ............................... Relative percentage abundance of foraminifera and other microfossils, Montesano Forma tion, Canyon River ......................... Relative percentage abundance of dominant and diagnostic foraminifera, composite Astoria Formation, Grays Harbor Basin . . . Relative percentage abundance of dominant and diagnostic foraminifera, Quinault Formation .................................... Depth classification of benthic marine environments ....... ................ Paleobathymetric foraminiferal faunas from the Montesano Formation .................... xiii Page j i 206 | i 217 ; j i 21 8 i i 219 | i ! 220 | i 24 1 250 270 274 I ABSTRACT The Montesano Formation has been mapped over about 250 Isquare miles of the Grays Harbor area, western Washington. lExposures are concentrated in three major areas: (1) in the 'vicinity of Cloquallum Creek, (2) along the West and Middle iForks of the Satsop River, and (3) along the branches of the jwishkah River. The formation occupies a broad, gentle, jeast-west trending depression, which is a remnant of a lar- jger Tertiary depositional basin. i Eight stratigraphic sections were measured along the branches of the Wishkah and Satsop Rivers, the Wynoochee River, and the Canyon River. Exposures of the Montesano Formation along the Middle Fork of the Wishkah River are idesignated the type section. There it is 2,500 feet thick land composed of 1,500 feet of fine-grained sandstone with ■small amounts of pebble conglomerate and mudstone overlain by 1,000 feet of tuffaceous mudstone and sandy siltstone. To the east the formation averages 1,800 feet thick and is composed principally of fine- to medium-grained sandstone, pebbly sandstone, and conglomerate. Along the West Fork of the Satsop River an abnormal sequence of thin-bedded to laminated, tuffaceous mudstone and very fine-grained sand stone at least 1,100 feet thick contributes to an over-all thickness of perhaps more than 3,000 feet. Where the base was observed, the Montesano Formation rests with distinct unconformity upon either the Lower Mio cene Astoria or Oligocene Lincoln Formations. The contact -is indicated by an erosion surface with up to 8 feet of relief, the borings of marine organisms, rounded clast$ of the underlying formation, an angular discordance in atti tudes of up to more than 30 degrees, a lithologic change, a Igap in faunal succession, and a sharp contrast in environ ments . The Montesano Formation is Upper Miocene (Sarmatian- jPontian of the European scale). A foraminiferal fauna con taining at least 84 species indicates that Wissler's 2 Rotorbinella (?) garveyensis zone of the upper Delmontian and Kleinpell's lower Delmontian Bolivina obliqua zone are represented in the upper half of the formation. The lower half is suggested to be, at least in part, upper Mohnian by jthe presence of Hanzawaia illingi. A correlation is made ■with the Briones, San Pablo, upper Monterey, Reef Ridge, McLure, Sisquoc, and upper Modelo Formations of California. Although relationships between the Montesano and Quinault Formations are obscured, the latter is dated Early to Middle Pliocene by planktonic foraminifera, making it younger than ithe Montesano. j Paleoenvironmental faunas defined for the Montesano (Formation include: (1) rock boring pelecypods; (2) Chione- iSoisula assemblages; (3) a Miliammina fusca fauna; (4) a jBuliminella elegantissima fauna; (5) a Nonionella fauna; j(6) a Bolivina fauna; (7) a Uvigerina peregrina hisoidocos- Itata fauna; and (8) a Bolivina seminuda fauna. A succession jof these assemblages, various other microfaunal trends, and jsedimentary evidence indicate that the formation was depos ited in a sea transgressing west to east over the land and Ithen regressing. In the western area water depths increased jprogressively from the littoral zone to more than 3,000 Feet. To the east environments ranged from the littoral zone to a depth of about 600 feet and then back to perhaps tidal sand flat conditions. The laminated mudstone contain^ |an impoverished fauna suggestive of a partially closed basin iabout 2,000 feet deep and with a sill at about 800 feet. Graded beds, convolute structures, filled channels, and a |high percentage of displaced fauna indicate that much of the sediment in the basin was emplaced by turbidity currents and slumping. Planktonic foraminifera indicate Late Miocene sea sur face temperatures in the Grays Harbor area of about 10 to 15 degrees Centigrade. The terrestrial flora reflects a mild temperate climate. I INTRODUCTION Purpose and Scope I i The search for petroleum resources in the Pacific I Northwest has followed a variable pattern (Livingston, i 1959). The latest interest is in the direction of offshore iareas. These areas hold considerable promise because the I ionly production has been on the coast of Washington (Wurden, 1959); moreover, the onshore geology suggests areas of thick marine Tertiary strata, particularly off Oregon (Byrne, 1962). Most rock samples from the Oregon-Washing- ton offshore area studied by this writer have yielded Late Pliocene foraminiferal assemblages. One can then anticipate that a thick Upper Miocene and Pliocene section exists off shore. A detailed knowledge of similar sections onshore is essential for proper interpretation of the offshore geology. During regional stratigraphic studies of the Tertiary jstrata of western Oregon and Washington, it became evident ; ! that very little was known of the Upper Miocene and Pliocend 3 Imarine rocks of that area. Few units of limited extent ! I I |have been referred to that part of the column. These are iprimarily the Empire Formation of Oregon (Diller, 1896; ! ! I jHowe, 19 33) and the Montesano Formation (Weaver, 1912), and! Quinault Formation (Arnold, 1906), both of Washington. The j Montesano Formation is the thickest and most widespread of ithe 3 units and, therefore, is the best formation to use i ; i ; ' I ifor a study of marine Late Tertiary strata of the Northwest: lUnfortunately it was poorly defined and its extent inade- : I quately known. Also, some question prevailed as to its j i relationship to the Lower and Middle Miocene Astoria Forma- j ! j tion (Pease and Hoover, 1957). i The present study was undertaken to define adequately j i I the Montesano Formation and to clarify its stratigraphic i position. Knowledge obtained will aid in the interpreta tion of the geologic history of the Northwest including its j ! offshore area. Emphasis has been placed upon establishment of the physical framework of the formation, delineation of foraminiferal faunas, and interpretation of paleoecology. j Various geologic mapping projects conducted by the writer from 1957 through 1961 contributed considerable 'knowledge toward completion of the present study. Most of June, July, August and September of 1962 were spent sampling 5 | and measuring stratigraphic sections. Enough geologic map- jping was done to outline generally the extent of the forma- i |tion and to establish relationships with underlying and ]overlying units. ! i ; Geographic Setting j The area studied is located largely in Grays Harbor jcounty, Washington (Fig. 1). Most of the field work was don ^ from the Chehalis River north to the foothills of the I iOlympic Mountains and from the Hoquiam River east to the town of McCleary. The Grays Harbor area occupies a structural and topo- I graphic low between the Olympic Mountains on the north, I : 'Black Hills on the east, and Willapa Hills on the south (Fig. 1). Etherington (1931) referred to this low as the Grays Harbor-Willapa Basin. Snavely and Wagner (196 3) . simply use Grays Harbor Basin. The latter term is prefer able because of simplicity and the central location of Grays Harbor. i , i Grays Harbor Basin straddles the boundary between the j i iOlympic Mountains and Willapa Hills physiographic provinces iof Culver (1936). However, neither of these warrants the jrank of province. The Olympic Mountains Province is j Pig. 1.— Location map of Grays Harbor County and sur rounding area, Washington. Adapted from sheet number N.L-1 (Cascade Range, 1957) of the International Map of the World 7 C O U N T Y FIGURE N/ [ i n \ ' ;C Wv . s > _ ~'/,oK i & MC C L E A R Y °J^I ^ | B LAC K - y \ HARBOR ^ o M O N T E S A N O O O L Y M P I A E L M A iHOQ UIAM A B E R D E E N - H I L L S BASIN C E N T R A L I A C H E H A L I S 1* • < FIGURE 4 CASTLE ROCK COLUMBIA '* 4 ^ WASHINGTON A S T O R I A ' OREGON 1 0 20 S T A T U T E M I L E S W A S H I N G T O N FIGURE I 0. A. FOWLER ISG8 77 jcommonly considered a section of the Pacific Border Province j j(Fenneman, 1931; Allison, I.S. in Highsmith, 1962). The Willapa Hills are an extension into Washington of the Oregon Coast Range Section of the same province. Allison arbi trarily placed the boundary between these sections in the southern foothills of the Olympic Mountains. Fenneman, in like manner, used the Chehalis River as the boundary. More detailed physiographic studies of the region might result in the definition of another section to signify Grays Harbor Basin. Until then, Allison's boundary is more acceptable than Fenneman1s. The Chehalis River Valley and the glaciated lowlands southwest of Hood Canal connect Grays Harbor Basin with the ! I Puget Sound Lowlands to the east. The basin opens westward j to the Pacific Ocean. Methods Field Work j i ! ; Data obtained in the field were plotted on the follow- I |ing United States Geologic Survey topographic quadrangle maps: Grisdale 1955, Mount Tebo 1953, Humptulips 1955, I Wynoochee Valley 1955, Elma 1953, Montesano 1955, Malone j 1953, and Raymond 1955 at a scale of 1:62,500; and Hoquiam i |1956, Aberdeen SE 1955 and Aberdeen 1957 at a scale of |1:24,000. Some U. S. G. S. aerial photographs at varying scales were also used. The data collected were transferred I to a base map constructed by combining portions of the fol lowing Army Map Service topographic maps: Seattle 1962, Hoquiam 1962 and Copalis Beach 1963, at an original scale iof 1:250,000 enlarged to 1:125,000. To obtain the measured stratigraphic sections of the Montesano Formation, attitudes and station locations were plotted on aerial photographs at a scale of 1:12,000. These! photos were obtained from Carl M. Berry, Photogrammetric Engineers and Foresters, Seattle, Washington. Originally I i designed for determination of type, size and number of trees, the photographs are of a quality and scale that ' allowed rapid and positive location of stations. Thickness- I es were then calculated directly from the photos using i trigonometry. More precise techniques are not warranted Considering the dense vegetation cover, weathering, slump ing, often massive lithology, and rugged terrain. In a few ! ! i instances, brunton and pace traverses were used to detail ! i local portions of the section. In areas of particularly i i poor outcrop control, an order of magnitude of thickness was obtained by calculations based on data plotted on topo- i graphic maps. Composite samples were taken through stratigraphic i .intervals of from 5 to 100 feet. For the selected type sections, samples were continuous throughout the column except where cover and weathering made this impractical. It was not possible to maintain perfectly uniform sampling Intervals because of rugged terrain, often unreliable atti tudes, and the switching of outcrops from one side of a stream to the other. Thickness sampled and the frequency pf samples were largely defined by the type of lithology, degree of weathering, per cent of exposure, and practical limits of the study. Continuous sampling through intervals i approximately 25 feet thick was undertaken in fine-grained | parts of the section where the probability of obtaining useful foraminifera was highest. This was not done where weathering and poor exposures made the practice inadvisable.; i Larger intervals of up to 100 feet were used in sandstone. ; j ■ Continuous sampling of sandstone was done only in the type Isection and the Canyon River section. Elsewhere samples j i ! from intervals 5 to 10 feet thick were used to represent j ! i apparently uniform lithologic units. i j ! From the standpoint of ecologic studies, composite ! 11 i I I samples through large intervals may result in averaging jmaterial from somewhat different environments. However, jthe methods used were considered necessary to insure better ;recovery of foraminifera. More refined studies of paleo- environments and detailed stratigraphic changes would re- Iquire sampling individual horizons at selected localities. All means at the disposal of the writer were used to iobtain fresh samples. They were taken in stream beds where high energy flow keeps the outcrops clear of most weathered [material. Excavation to a depth of a few inches generally yielded good results in outcrops of mudstone and sandstone with a large content of silt and clay. Porous and permeable] sandstone, however, often is leached deeply even in stream ! bottoms. 1 1 | Laboratory Analyses In the laboratory, a representative split of about 100 j grams was selected from the dried field sample. This was crushed to about pea-size fragments and weighed to the nearest tenth of a gram. Soaking in water disaggregated ! jsome sandstone but not mudstone and sandstone with a large ^percentage of fines. For these it was necessary first to j i ! i isoak the samples in kerosene. Mild agitation and heating I helped to speed up the process. After disaggregation the samples were wet sieved on a screen with 0.0025 inch open- t ings to remove most of the silt and clay. The dried coarse ! I I fractions were then examined for foraminiferal tests and associated organic remains. Initial attempts were made to separate foraminiferal tests and other microfossils from the detrital portion of the sediment by floating them on ; I ; iper ch lor ethylene . Separate examinations of the flocited I concentrate and residue yielded significant differences in i i j ;species percentages obtained. Rather than being forced to j 1 I imake separate counts on the 2 fractions, it was decided to i no longer attempt concentration. A modified Otto micro- j split was used to obtain fractions from which all organic j I I i remains could be counted. Where present, from 200 to 300 j i . I specimens of foraminifera were counted in each sample. Thi^ i represents an optimum range for quantitative studies of foraminiferal populations (Phleger, 1960). | Lithologic descriptions in this report are based pri marily upon analyses of hand specimens. These were aug- j jmented by examination under a binocular microscope of the ! I sand fractions obtained from the disaggregation of samples for study of foraminifera. All samples used in this study are on file in the ! 13 Micropaleontology Laboratory of the Allan Hancock Founda- | tion, University of Southern California. i I i I Acknowledgments ' i i i The writer is grateful to all who have contributed in any way to the completion of this study, even though indi vidual acknowledgment is not given. Special thanks are due j :Dr. 0. L. Bandy, chairman of the writer's committee, for his, continued interest and assistance. A grant from Union Oil i i ,Company of California to partially defray expenses greatly ; facilitated this work. Weyerhaeuser Timber Company and j : I Bimpson Logging Company cooperated by allowing access to I their property. Supervisor Marshall T. Huntting, Dr. Weldon W. Rau, and others of the Washington State Division of Mines! I | and Geology contributed through their interest, help in the I j field, and discussions. Drs. 0. L. Bandy, W. H. Easton, I i and J. W. Reith have critically read the manuscript. Thanks are due Ronald Hill, Sally Kulm and Donald Cunningham for | I 1 j help in drafting the illustrations and to Maynard T. Smith ! for editing and typing assistance. Office and laboratory i jspace and library facilities were supplied by the Allan Hancock Foundation, University of Southern California. Finally, particular gratitude is extended to the writer's family and fellow students for their understanding, encour- j |agement, and help. | PREVIOUS WORK i i i ] j l : I Reference to the geology of western Washington goes jback at least as far as the reports of the Lewis and Clark i Expedition of 1804 to 1806 (Bennett, 1939). Despite this early beginning, very little is known of the detailed geo logy of much of this region. Even the broad patterns are obscure in many areas. Published accounts are few in num ber and generally of a restricted coverage. j The Grays Harbor area has never attracted a large pop ulation and general interest. One reason is that it is not , located on one of the early main travel routes. The absence} i | j o f valuable metallic and non-metallic mineral deposits has 1 ' I offered no incentive for geologic mapping. Exploration for and development of coal resources have yielded detailed geologic studies in certain parts of western Washington j (Beikman, et al., 1962) but not in the vicinity of Grays j j j Harbor. Abundant geologic data have been obtained by oil companies through the intensive search for petroleum ^conducted in the region for many years (Livingston, 1959). I These data, however, are not available to the public. The | . effect of dense vegetation and deep weathering in the icoastal areas of the Northwest has been to produce few exposures and these are of poor quality. The earliest geo logical operations were restricted to good exposures along Stream courses and sea cliffs. Construction of extensive I 'networks of logging roads and railroads has created many (additional outcrops. Their usefulness, however, is often j of short duration because of rapid weathering and growth of vegetation. Therefore, outcrops discussed in the liter- j ' ature frequently either cannot now be located or used with confidence. Proper identity of early locations, of course, : is further inhibited by poor quality maps and lack of pre- | cision on the part of investigators. Logging roads have increased the accessibility of many areas. On the other hand, debris left by early logging operations has clogged I 1 I streams, obscuring outcrops. In addition to vegetation and j i I weathering, alluvial and marine terrace gravels, sands, and | j Silts (the Satsop Formation of Bretz, 1913) form an exten- ! I | Sive cover over strata under discussion in this report in i i i jparts of the Grays Harbor area. The common flat-topped j Stream divides are underlain by this unit. These facts mustj jbe kept in mind while evaluating previous studies and this I ; i jreport. | Weaver (1912) named the Montesano Formation for Upper I jMiocene strata cropping out north of the Chehalis River in the vicinity of the town of Montesano. The lithology was i ; described as light brown, massive, coarse-grained sandstone in the lower part with many intercalated lenses of conglom erate and grit. Shale was considered to be subordinate in the lower portion but common in the upper. Stratigraphic t I thickness was given as approximately 5,000 feet. A general ized geologic map of western Washington illustrated the i ; i 5 formation extending from Hoquiam east to half-way between Elma and McCleary and from the Chehalis River north to al- I most the southern foothills of the Olympic Mountains (Fig. : 2a). It is noteworthy that the base as mapped by the wri ter coincides with the base as originally mapped at only one spot— the extreme northern limit. The megafauna was ponsidered to be distinct from that of the Early Miocene i j j 'ana was related closely to the fauna of the Empire Formation] ! ! of Coos Bay, Oregon and to the San Pablo Formation of Cali- j j I jfornia. No type section was designated nor measured sec- ! j : tions given. | i i ! In their discussion of the marine Tertiary stratigraphy I I Fig. 2.— Comparison of previous geologic maps of the Montesano Formation with that of this study. a c t • to STATUTE MILES 2 o - W E A V E R , 1912 1 0 9 0 1 0 STATUTE MILES 2 « — WE AVER , 1937 O 9 1 0 STATUTE MILES 2 b - A R N O L D AND HANNIBAL, 1913 T « s o 1 0 STATUTE M ILES 2 1 - HUNTTINS, E J AL., 1961 1 0 STATUTE MILES 2 c - W E A V E R , 1916 * * i T * K A M O S 0 STATUTE M ILES 2 g - T H I S PA PER » S 0 STATUTE MA.ES 2 4 - ETH ERINGTON, 1931 i i I I DISTRIBUTION OF THE M ONTESANO FORMATION (contact d a s h e d w h e r e a p p ro x im a te ) F I 8 U R E 2 u f m u < I 20 i i I I of the Northwest, Arnold and Hannibal (1913) interpreted jWeaver as intending Montesano to be a local name for the Empire Sandstone. These authors considered the formation i | ito be present over a much greater area than did Weaver (Fig. 2b). Their interpretations were based upon limited [field work and fossil collections from scattered localities. i ; [For these reasons arbitrarily placed formation boundaries I ' iwere used extensively on their map. In the light of later investigations, Weaver's geologic mapping and interprets- j ; [tions were much more accurate than those of Arnold and Hannibal. However, their discussions of the formations i i l exposed along the Main Fork of the Wishkah River are still I fairly useful. This area was not mentioned by Weaver in ' 1912. The formation was described as being 4,000 feet thick ‘ I and as consisting chiefly of sandstone at the base, grading ! upward into massive tuffaceous shale. The reported thick ness is greater than that obtained in the present study but j the lithologic description is approximately the same as j I ; found by this writer. The contact between the basal sand- i i : i istone and Oligocene-Miocene shale, considered by Arnold and ; j | Hannibal to be a fault, was located in the same place as i [determined in this study. Thexr Empire Sandstone was con- j j jsidered to be Middle Miocene in age and to contain a fauna j Iwhose closest affinities are with the fauna of the San Pablo ! jFormation of the San Francisco Bay region. I In a more detailed analysis of the Tertiary geology and i . j paleontology of western Washington, Weaver (1916) consider ably altered his earlier views on the distribution and na- i ture of the Montesano Formation (Fig. 2c). It was shown to cover more than twice the area as mapped originally. Parts of the area are now known to contain outcrops of strata at least as old as Late Eocene and some which are thought to i be Pleistocene. A stratigraphic section for the Montesano Formation was measured along the Wishkah River and reported to consist largely of shale in the basal portion and sand stone and conglomerate in the upper part in contrast to his 1912 statement. Attitudes plotted by Weaver along the site I of the measured section are shown oriented in a direction opposite to the orientation determined by this writer. The i stated thickness of 5,400 feet is about double that obtained in the present study. j I Hertlein and Crickmay (1925) mentioned the Montesano j Formation in a summary of previous reports on the strati- j jgraphy of the marine Tertiary of Oregon and Washington. No j I jnew data or conclusions were presented. I i [ I i Although primarily concerned with the Astoria Forma- i | 22 ; i jtion, Etherington (1931) discussed briefly the Montesano i jFormation. His geologic map depicts a portion of the extent of that formation (Fig. 2d). The outcrop pattern is about ; the same size and shape as that determined by this investi gator for the area he covered, but differs considerably in Idetail, particularly along the lower part of the Satsop River. Etherington1s basis for dividing the Astoria and I jMontesano Formations was solely their faunal content. This iwas the method used by most, if not all, of the early in vestigators. Some of these workers were not fully aware of environmental problems and often used single, sometimes fragmentary specimens for identification rather than care fully analyzed groups. Etherington considered the faunas ! of the Astoria and Montesano Formations to be more closely related than are those of the Astoria Formation and under lying Upper Oligocene. The present study has not demon strated similar relationships between foraminiferal faunas of these formations. The general lithology was stated as consisting of a basal conglomerate, followed by 1,500 to ;2,000 feet of sandstone and an additional 2,500 feet of shale west of the area he studied. A significant pre- 'Montesano stratigraphic break was noted with the Montesano jFormation resting on Eocene basalt in the east, and upon pligocene and Miocene strata progressively westward. The most recent and comprehensive statement concern ing the nature of the Montesano Formation is included in a third study by Weaver (1937). This study considers the formation as occurring in two shallow, westerly plunging synclines (Fig. 2e). The eastern half of the largest of I these was mapped essentially the same as presented by iEtherington. Formational boundaries were extended west- l ward by Weaver to the Wishkah River. He drew the northern basal contact on this river 4 1/2 miles downstream from his location in 1916 and 2 1/2 miles downstream from the location determined by this writer. Weaver apparently placed the contact between the Satsop Formation and the Montesano Formation as used in the present report. He considered rocks beneath his Montesano Formation on the Wishkah to be part of the Middle Miocene Astoria Formation. His placement of the northern basal Montesano contact on the Wynoochee River is the same as in this study. Straight lines were drawn through basal contacts on the Wishkah, Wynoochee, and Satsop Rivers to form the outcrop pattern of the formation. The small syncline in the Aberdeen area was defined about as it is in this report. Weaver considered the Montesano invertebrate fauna to have affinities with tooth. Late Miocene and Early Pliocene faunas. A maxims thickness of about 4,000 feet was given. He regarded massive sandstone south of Montesano, originally inclu in the Montesano Formation, to toelong to the Astoria P tion. Little shale was included in the formation. In a review of the paleontology of the marine T e r strata of Oregon and Washington, Weaver (1943? listed, illustrated and described 38 species of invertebrates the Montesano Formation. This is in contrast to fel sjp he reported in 1912 and more than 70 species m his 19 report. The discrepancy is largely the result of his ing views as to what the formation included. Weaver's sil localities 117 through 125 on the Middle Fork of t Wishkah River contained assemblages he considered Midk Miocene and therefore representative of the Astoria Fc tion. These localities are in the measured section gj toy Weaver for the Montesano Formation in 1916. Or th* of foraminiferal faunas and physical stratigraphy tfeu vestigator agrees with a Middle Miocene Astoria Formal designation for material at Weaver's localities iI" ti 122. However, 123 through 125 belong in the Montesaru mation of this report. A correlation chart shows the mation as questionably ranging in age from latest Rio both Late Miocene and Early Pliocene faunas. A maximum thickness of about 4,000 feet was given. He regarded a massive sandstone south of Montesano, originally included in the Montesano Formation, to belong to the Astoria Forma tion. Little shale was included in the formation. In a review of the paleontology of the marine Tertiary strata of Oregon and Washington, Weaver (1943) listed, illustrated and described 38 species of invertebrates from the Montesano Formation. This is in contrast to 61 species he reported in 1912 and more than 70 species in his 1937 report. The discrepancy is largely the result of his changJ ing views as to what the formation included. Weaver's fos sil localities 117 through 125 on the Middle Fork of the Wishkah River contained assemblages he considered Middle Miocene and therefore representative of the Astoria Forma tion. These localities are in the measured section given by Weaver for the Montesano Formation in 1916. On the basis of foraminiferal faunas and physical stratigraphy this in vestigator agrees with a Middle Miocene Astoria Formation designation for material at Weaver's localities 117 through 122. However, 123 through 125 belong in the Montesano For mation of this report. A correlation chart shows the for- j i : 1 mation as questionably ranging in age from latest Miocene tcj 25 ^ate Middle Pliocene. It was correlated with the Empire Formation of Oregon and the Upper San Pablo Group, Jacalitos Formation, and Etchegoin Formation of California. Later, Weaver (in Weaver, ^t ad., 1944) considered the Montesano Formation to be almost entirely Pliocene and younger than the San Pablo Group. He states the following: The Montesano Formation is a composite from numerous sections exposed in the banks of the Wynoochee and Wish kah Rivers and their numerous tributaries. The maximum exposed thickness is 2,800 feet, but still younger beds further west are concealed beneath thick deposits of Pleistocene gravels and sands. At certain localities the formation is unconformable on the Astoria and Lincoln Formations; its relation to the younger Quinault Forma tion is concealed. This final statement by Weaver regarding the Montesano For mation, although brief, summarizes very nearly the same facts as observed by this investigator. It is unfortunate that he did not later publish a clear and complete descrip tion of the formation. It is obvious that Weaver considered the Wynoochee and Wishkah Valleys to contain the best and most typical exposures of the Montesano Formation. However, a carefully located and described type section was not designated. The stated thickness of 2,800 feet is a close approximation to that found by this investigator on the Main Fork of the Wishkah River. j I Brief mention was made of the Montesano Formation by i 26 : Pease and Hoover (1957) in connection with geologic mapping i pf the Doty-Minot Peak area. They were unable to locate the Astoria-Montesano contact drawn by Weaver (1937) and Ether ington (1931) south of the Chehalis River between Montesano and Elma. The lithologies were considered to be identical and all were mapped as the Astoria Formation. Pease and Hoover decided that an approach such as this was necessary until mapping was extended northward into areas where more of the Montesano Formation in typical form crops out. On the latest geologic map of the state of Washington (Huntting, et al., 1961) units are referred to by age rather than by formational name, a practice common on large scale maps where detailed geologic mapping is not available. The lithologic description, age, and aerial pattern of the unit called Miocene-Pliocene marine rocks, indicate that it is the Montesano Formation of the present report. However, no formational name is given for the map designation in the accompanying explanatory text. The Montesano "Series" (Weaver, 1916) is included under Quaternary Terrace Deposits on the state map. Although it is true that Weaver in 1916 mapped a portion of these latter deposits, along with other units in the Montesano Formation, there is no evidence that he considered the Montesano to be Quaternary. It is most s 27 > probable that the inclusion was a result of discrepancies in field mapping and poor faunal control. The distribution of Miocene-Pliocene marine rocks on the state map (Fig. 2f) is, as far as scale and detail will allow, about the same as determined in this study (Fig. 2g) . The principal, ex ception is a window of Astoria on the lower portion of the West Fork of the Satsop River of which no evidence could be found during the present study. Some of the data used in compilation of the state map came from confidential oil company files and were not available for examination by this investigator. Youngquist (1961) in a review of Tertiary stratigraphic nomenclature for western Oregon and Washington gave the age, type section, distribution, and original description of the” Montesano Formation as he found them stated in the litera ture . This review of previous work on the Montesano Formation: has pointed out the confusion that evolved concerning its identity. Considering the geographic factors discussed earlier, it is not difficult to understand how such an in exact picture developed. However, from the confusion one can establish a framework from which to start to clarify j the situation. The following points serve to define ! 28 i i Weaver's thoughts on the Montesano Formation: (1) it ranges in age from Late Miocene to Early Pliocene; (2) the lithol- ogy is predominantly sandstone with smaller and variable amounts of shale and conglomerate; (3) best exposures are along the Wishkah and Wynoochee Valleys; and (4) the forma tion unconformably overlies the Astoria Formation and older units. REGIONAL GEOLOGIC HISTORY It is desirable to outline the regional geology of an area and the sequence of geologic events before discussing in detail a single unit. However, the latter is often more easily done than the former. Many portions of western Ore gon and Washington remain essentially unmapped and strati- graphic problems unsolved. Considerable extrapolation and interpolation are necessary to achieve any kind of a region al synthesis. Certainly, statements made now will require change, perhaps of a considerable magnitude, as more areas are mapped in detail and stratigraphic columns carefully studied. Excellent studies in some areas afford a fine basis for regional interpretation. These investigations were conducted largely by the United States Geologic Survey under the direction of Parke D. Snavely, Jr. The most recent and authoritative view of the Tertiary geologic history of western Oregon and Washington is given in a summary by 30 Snavely and Wagner (1963). It is based upon over 15 years of geologic investigations in the region by the senior author and many of his associates in the U. S. G. S. Their report along with the state geologic map of Washington (Huntting, et aj.. , 1961) and field work by this writer form the basis of the statements to follow. The oldest known Tertiary rocks in western Washington are the basalts, often with pillow structures, and inter calated deep-water marine sediments of the Lower to Middle Eocene Crescent Formation (Arnold, 1906) (Fig. 3). Expo sures of this formation almost completely encircle Grays Harbor Basin, cropping out in the foothills bordering the Olympic Mountains, in the Black Hills, Doty Hills, Willapa Hills, and smaller topographic highs (Fig. 4). A thickness of 10,000 to 15,000 feet has been given for exposures along the north side of the Olympics (Brown, Gower and Snavely, 1960). It could be thicker on the south side where outcrop patterns are wider. The Crescent Formation has been en countered in many wells drilled in southwestern Washington and correlates with similar volcanic and sedimentary units present throughout the Oregon Coast Range. The widespread Crescent Formation represents initial marine deposition and volcanic activity in a broad, 400-miL Fig. 3.— Composite columnar section of Tertiary strata in Grays Harbor Basin. Compiled from data in Pease and Hoover (1957), Rau (1958), Snavely, et, _al. (1958) and this paper. 3 ) © c 2J m 0 1 EOCENE OLIGOCENE MIOCENE o -o m r 2 o m i CRESCENT . . , • i • i : i - i < hLi *;£ m : i I - H I iR MC INTOSH LINCOLN ASTORIA MONTESANO j l j l j l $!;&$! i i i ! Ij'jliil 2 o x M r v > m o O -n m m » o o 0 1 3 o o o Oi o O o o o o w 1 O I tn O O o o o » o o 0 1 5 8 M 8 0 1 iM O O o o o 0 1 o» o o o ■ n X « z m m h w < • >90 Z oo m ( « enu > o « X PI o * r n? x * X — J « e © •or " o ' * ; 5 » f S ;Sq- 5 * ; u ° 5 5 ; 5 s S<*_ r -4-JzH oo-t" x * ro x a m i o ■ t t ( 0© c » n S < - 4 P I o*o X H • 09O S _ ~ -2oi c x - * ’ a as** apimra »oro -or o *rn m "o _o ° s * “ is ™ *0-1 ; %’ " o “ Hu C = C “> Z * ! » » » * u > h r ° a * L « - "53S n r com a* © a x « o < > ’ S i X ?a Sti * a - i n ^5" • o x a-t O o oZ x n t m (■OO * c on. xo r • _ c c ■ « » ■*s J * * z o o a Z CJEF* <*zm<»2 « " ~ l< ®OoO." m * m ; ? - * * <« °<*roaH n o ? 5 o o j i : * i # < ? > S " s ^ ? * s 5=3-5 &H ■ " o "S -? S Oc 9 1 or o m. az o gn o m» os • O ?5= < Him o >• m o 5°E ; 8 " Ooo ana »o> - 3 s X «* o ° = r a 0 ) * ” H o 0 * 0 ©x o n *© ® o if si m H^| S ! m> o r 2- q r > kAO I" 0 2 U) ro Fig. 4.— Geologic sketch map of Grays Harbor Basin. Adapted from Huntting, £t ad. (1961) with modifications north of the Chehalis River from data in this paper. Dis tributional trends are simplified and generalized in order to best demonstrate over-all patterns. 34 HO QUIA A BERD EEN TOL^ R EC EN T 1 0 MIOCENE 1 0 M IL E S m ALLUVIUM AND DUNES P L E ISTOCENE Q O I G L A C IA L M O N T E S A N O F O R M A T IO N A S T O R IA FO R M A T IO N EOCENE E 3 M e lN T O S K F O R M A T IO N £ 3 3 3 C R E S C E N T h l i S i J F O R M A T IO N [ q t ] S A T S O P F O R M A T IO N O L IGOCENE F F S lI L IN C O L N f ■ F O R M A T IO N IN T RUSIVE PLIOCENE O U .N A U L T F O R M A T IO N SEE LEGEND ON FIGURE 6 f i g u r e 4 35 j ilong Tertiary geosyncline that extended from near the southern border of Oregon to the southern end of Vancouver Island (Fig. 5). Snavely and Wagner (1963) call the geo syncline a eugeosyncline; however, the term epieugeosyncline of Kay (1951) is more appropriate and will be used in the present discussion. From its inception the epieugeosyncline continued to accumulate sedimentary and volcanic strata, perhaps in places without interruption, through the Tertiary. Submarine and subaerial volcanic activity was irregularly distributed within the trough and gradually decreased with time . Uplift and erosion of bordering highlands during Middle Focene time resulted in thick deposits of arkosic sand along the margins of the trough and the deeper central portions particularly in the Oregon Coast Range section. Continental deposits with abundant coal beds predominate on the north east border of the geosynclinal area. These are replaced by deep water mudstone with minor sandstone in the Grays Harbor area (McIntosh Formation of Snavely, et aJL., 1951). During the Late Eocene, local uplift and vulcanism re- ! duced the size of the epieugeosyncline and produced several individual basins. Essentially continuous deposition took j i place in the centers of these but local unconformities were ! Fig. 5.— Possible outline of the Tertiary epieugeosyn cline that occupied the area of western Oregon and Washing ton during the Early Eocene. Adapted from Snavely and Wag ner (1963). Pig. 5.— Possible outline of the Tertiary epieugeosyn cline that occupied the area of western Oregon and Washing ton during the Early Eocene. Adapted from Snavely and Wag ner (1963). 37 CANADA UNITED STATES SRAYS r HARBOR BASIN * Woshington; Oregon k INFCRRCO MARGIN OF EARLY EOCENE E P I E U O E O S Y N C L I N E Oregon Californio o BO 100 MILES FIGURE 5 *. A. FOWLER, l » « 8 38 j commonly developed along the margins, particularly toward the east. In the Grays Harbor area marine sediments re ferred to the McIntosh Formation (Rau, 1958) were deposited.: I ! j Reduction in size of the epieugeosyncline continued on 'through the Oligocene in Oregon. In the northern half of |the trough, however, subsidence resulted in enlargement of basins. Transgressing seas deposited sediments across I Upper, Middle, and Lower Eocene sedimentary and volcanic i |strata. Through the Tertiary Period almost continuous vol canic activity to the east of the epieugeosyncline contri buted ash and larger pyroclastic debris to the marine sec tion. This activity reached a vigorous maximum during the Middle Oligocene. The distinctive, highly tuffaceous mud- I i stone, siltstone, and fine-grained sandstone and interbedde4 i j tuff of the Lincoln Formation (Weaver, 1912) were deposited I i primarily during the Oligocene but range from highest Eocen^ to lowest Miocene. Unweathered exposures of this formation! and equivalent units are readily recognized over large area^ i j i of western Oregon and Washington. i : i ! ! Increased orogenic activity, along northwest-oriented | ! ! 'structural trends in western Washington, further reduced ; basin size in the Early Miocene. Erosion of corresponding highlands to the east and elsewhere resulted in the coarse 39 clastic sediments that characterize the units deposited i jduring the Early and Middle Miocene. Also, local unconfor- j mities are common between the Lincoln Formation and the ; J I joverlying Astoria Formation. In places the latter overlaps , iStill older units. In deeper portions of the basin, how- jever, sedimentation continued with little or no interruption ifrom Lincoln to Astoria time. ; j i i Usage of the term Astoria Formation was extended from jthe type locality around the town of Astoria, Oregon to the IGrays Harbor area by Etherington (1931). There is doubt j i regarding the validity of that usage (Snavely, et. al.. |l958) . However, it has become common practice among strati-! i , I graphers to place Lower to Middle Miocene sandstone and j ! I j I shale in southwestern Washington within the Astoria Forma- i i | jtion. The unit most typically contains large quantities of i iarkosic sandstone in Grays Harbor Basin. It is most coarseH ly grained and contains conglomerate beds and abundant I debris along the eastern margin (Snavely, et al., 1958; Pease and Hoover, 1957). A well defined transition can be I 1 | i j observed from terrestrial deposits westward through typical j continental shelf-type sediments to organic rich mudstone i j containing little sand, deposited in bathyal depths. Ash, j jalthough common, is not as abundant as in previous strata. I __________________ „_ _ _______ _ _ _ _ _ ___________ 40 | Basalt flows, often exhibiting pillow structure, occur fre- i jquently interbedded with the Astoria Formation along the jeastern margins of the Grays Harbor and adjacent basins. j jThese flows are known to extend westward at least as far as i 1 i iHoquiam. The basalt underlies prominent cuestas and other I ielevations south and west of the Doty Hills and south of i : ’ Aberdeen. i ; j | During late Middle Miocene time, renewed and more !vigorous deformation took place along essentially the same ! . . | trends as were established previously. Most intense activi-t | j ty occurred north of the Chehalis River where the Astoria i I ! ^Formation and older units were in places sharply folded and faulted prior to deposition of the next unit. This activity j i iresulted in a retreat of the sea from most of the Grays i i i j ! Harbor area. It is possible that deposition continued without interruption in the southern and western parts of the basin. Pease and Hoover (1957) report brackish to fresh j water deposits interfingering with and overlying typical I lAstoria strata in the vicinity of the Doty Hills. Leaves j j |from the former deposits were dated as Middle to Late Mio- |cene. To the west, molluscan faunas from strata near the | i Stop of what has been tentatively called the Astoria Forma- ! jtion are considered to be of Late Miocene age. No fauna has been reported from the highest exposed rocks in the same area. | By the Late Miocene, downwarping allowed the sea to I [re-enter a much smaller Grays Harbor Basin and this resulted in the deposition of the Montesano Formation. Shallow water; [marine sandstone of this formation can be observed resting I junconformably upon the eroded edges of folded and faulted i i [Astoria, Lincoln and Crescent strata along the northern edge; !of the outcrop area. Relationships along the southern i I I ) [boundary are not as clear but apparently the Montesano For- ; jmation is overlying only the Astoria Formation and with less! ! ! 'unconformity than to the north. Contemporaneous non-marine j [deposits, such as the Wilkes Formation (Roberts, 1958) 5 i 1 dropping out to the southeast of the Grays Harbor Basin, I Iwere formed in local basins. ' ■ i Through basin filling and further uplift, the strand [line and sedimentation migrated westward through the Plio- ! i I jcene. Very little can, as yet, be determined about Middle [Pliocene marine deposits in the Northwest because of limited [exposures. The Quinault Formation which crops out in smallj i [ jsomewhat isolated areas on the coast about 25 miles north [ i I iof the mouth of Grays Harbor is of this age. Wells have i ireportedly encountered it in the vicinity of Grays Harbor 42 I I (Wurdon, 1959). The formation is composed of sandstone followed by mudstone. Deposition took place in outer sub littoral to bathyal environments. | j Late Pliocene deformation elevated the Olympic Moun- ! ’ tains, Oregon Coast Range, and Cascade Mountains to very ' i nearly their present stature. The Montesano and Quinault Formations exhibit gentle folding and faulting developed by , I that deformation. I Subsequent erosion and basin filling transformed the I i , i ferays Harbor area to a surface of low elevation and relief, ; resulting in the accumulation of alluvial, lacustrine and j Jparalic deposits. Poorly consolidated, highly oxidized conglomerate, sandstone and siltstone of these types, formed ! ! during the Pleistocene in this area, are generally referred ! i i i . ! ;to the Satsop Formation (Bretz, 1913). Up to several hun- ■ i dred feet of this material, at one time, probably covered ; | I all except the highest parts of Grays Harbor Basin north j i ; :of the Chehalis River and the western portion south of the j i | jriver. Later broad uplift enabled some of the present streams to cut through this cover. Remnants form flat itopped cappings on hills and ridges. The thickest accumu- i i jlations have not yet been penetrated. MONTESANO FORMATION i I i i i | I Areal Geology j i j ! j Although this was never intended to be a mapping prob lem as such, a considerable amount of field mapping was jnecessary in order to delimit the areal extent of the Monte sano Formation and its relationship to underlying units. i jPrevious to the present study the most detailed geologic j ; J ; , 1 map available of the Grays Harbor area between the Chehalis j i ; iRiver and the Olympic Mountains was that of Weaver (1937). < I His map was compiled at a scale of about 1:151,000; howeverj ! ' j contacts were drawn only approximately and few attitudes Were given. A more recent map, at a scale of 1:500,000, was| compiled by Huntting, et .al. (1961). Although it contains j more up-to-date information, only generalized patterns could i ■ ! I be illustrated at the small scale used. j I . j Because of a lack of an adequate large scale geologic | map for the area containing the Montesano Formation, it was idecided that an attempt should be made to compile one from data obtained in this study (Fig. 6). Poor and limited \ jexposures have resulted in a degree of uncertainty for parts | ! ; i of the study area. These will be accounted for in the dis- ! ! ■cussion to follow. Exposures of the Montesano Formation can be grouped | ;into 3 major areas (Fig. 7). In order from east to west, ithese are: (1) in the vicinity of Cloquallum Creek and ! j i i iwest to the Satsop River (I), (2) along the West and Middle j Forks of the Satsop River (II), and (3) along the Wishkah ! ! |River and Newskah Creek (III). The structural geology, j icontact relationships and general nature of exposures will ; | ! be discussed for each area in order. Details of the strati- 7 Igraphy and fauna will be examined in later sections of this j j I report. i ; I Cloquallum Area The formation is least well exposed in area I (Fig. 7). Although the basal contact was nowhere observed, fair I jcontrol was obtained between closely spaced outcrops along the north and east sides. Best examples are in Cloquallum Creek near the Grays Harbor County line and in Wildcat 'creek about 3 miles west of McCleary. To the south and west 'relationships are obscured by alluvial deposits of the i Fig. 6 .— Geologic map of the area containing the known exposures of the Montesano Formation in Grays Harbor Basin. Base map adapted from U. S. Army Map Service Western United jStates 1:250,000 series maps, Seattle and Hoquiam sheets. I J — ! ^ ■ '! -* -"_, < f « / - ' l " j r . X 1 ) ' , ) i ~ ) - -4- ^ • • ' •' # , | r / - ' . ' ' ' ' 7 • ^ ' / ' Q> / f ' l l l P : ' ' , ’ 1- .*v->~. >'vJS^y*Z>> a r v L e li « 8 F ’• • •-• » • j2 * \ “ i 1 %20^in&PZi7£te WsCTS! m i M m l * t I & ^y:: J b A f ' > ♦ I ^ • i s § ^ l W pi Mf ? s ? ’*;-.;.C:M::' / } * ? & ? ( '3 '- — ' . ' t rao £ V j j ^ . V \ . / ] . f * > ! ’ $ 7 < t l * < r a^=M• ; / « # . .^:y . O '? . •'Jl-H'ma ■ ' ■ '• V ■ '■ '•'''U -'.: •'.• : . • • / W f t i 'L -1 » • I L r PLIOCENE - RECENT Qal ALLUVIUM auth her g^t^LPk^:^ Aloer MIOC ENE 1 1 iiWk. p u l h M . o n t f l i a h ’ [■ q i j S A T S O P F O R M A T I O N •T frtrn .l m o n t e s a n o f o r w a t io I ---1 ; 3 r j ; I T m a | a s t o r i a f o r m a t i o n v' - \ - - .-r.^'X' _.X '• " 1 . '-V' ✓ -\S ' ' x , ' z f r > > y . * ; : : ^ x OLIGOCENE LINCOLN FORMATION 3 T A T U T E M IL E S CONTOUR INTERVAL 2 0 0 FEET EOCENE | T e c I CR ESCENT FORMATIO N O T E ■ the d i s t a h u t ion* op a, MAO E TO SHOW THEIR PAT C MT 0 E P 0 SITS . FIGURE 6 R 5 W R 7 W R 6 W a- i f j r s * .'• ■ ■njrrvj✓wtfiSgx v w s ^ W m S p ■' arlock ) .xtThHwTki’ l T m m *.. • V V : l^ » . - :74-A /-i ; 5 7 G . 0 I ’ a i r f n j f i d l i ' L i ¥ F " ' * f . w m m m m m / 1 > < « * w h j e «/> i -uAr *; ±j. v . Q^ f . ' o f » ■ « - ■ * • •l_- ' * Y~:r TS* . l . cl. J- 1 •£<f ■ . f- ■ ' L'Av«;;/-v 5»a• • ■ » / W ' V^USK ' X f ( T , * 94 * f c A l . V w u f e S f r f e a w m i W J f M * Cem'-/d*»V©MiiP® ^t > Q t , /ag Ay lSiot 3 p r fr3 /•: ^ ' ' ’ ■ ' , c i i A J r n a i U > s | a j i o n PLIOCENE - R EC E N T Qo l I ALLUVIUM FORMATION CONTACT OASHCD W ME RE »»PRO* IM »T E ; DOTTED « H E R E C O N C E A L E D OUEAlED WH E R E VERT U NCE RTA IN • — ARBITRARY CUT GENERALIZED Amer t j l H r i t ^ S a r T ' s a t s o p f o r m a t i o n MIOCENE MONTESANO FORMA TI ON T m m FAULT T RACE E NOTES ABO VE ; RELATIVE I E N 3 E OP MO BY ARROWS AND L E T T E R S T m a ASTORIA FORMA TI ON O il GOCENE L INCOLN FORMATION v‘ v \~. .^•V,,;C'. - 46 N t 10 EO CENE | T e C | C R E S C E N T FORMATION FOLD AX E S S H O W I N G DI RECTION OF PL UN GE s e e N O T E S ABOVE ■ 7-^- ANTICLINE 5 2 ----------- S T N C L I N E IB STRI KE AND DIP OF B ED S Ml L E S t RV AL 2 0 0 F E E T NO TE 1 THE DISTRIBUTIONS OP Q AL AND QT ARE BRCATLY I C N C R A L I Z f 0 . NO ATTEMPT HAS BE E N MAO E TO SHOW THEIR DISTRIBUTIONS WHER E THEY OCCUR * • VERY THIN AND PATCHY OEPOSITS. a A. r o w i l R , I BBS Major outcrop areas of the Montesano Forma- 48 t £ M O N T E S A N O R I V E R cm£haus creek N i I CLOQUALLUM CREEK AREA E o SOUTHERN SATSOP AREA l i b NORTHERN SATSOP AREA M o SOUTHERN WISHKAH AREA H I b NORTHERN WISHKAH AREA ( S t * L t g i n d F o r F i g u r * 6 ) MONTESANO FORMATION 1 0 S T A T U T E M I L E S F I O U R E 7 * . » . r o w L i * 49 | Satsop and Chehalis Rivers and by the Satsop Formation. | The Montesano Formation unconformably overlies massive, tuffaceous mudstone of the Lincoln Formation on the north I i j land east. Judging from conditions south of the Chehalis kiver, the Montesano Formation probably rests upon the I I Astoria Formation beneath cover on the south and west. 1 i A maximum dip of 26 degrees and an average value be tween 10 and 15 degrees were measured for outcrops of the jviontesano Formation. A maximum of 38 degrees was recorded jnear Price Lookout between the Satsop and Wynoochee Rivers; ; I i |however, the over-all average is about 15 degrees. The few | j I (attitudes obtained in the Cloquallum area indicate an east- ! ! i {west trending, shallow syncline plunging westward. Irregu lar attitudes and small faults in the formation at the mouth I bf Cook Creek, in the northwest corner of area I are sugges- I ! tive of proximity to a significant fault. The straight i i feast-west course of Cook Creek and the steep hillsides on i i the south side further suggest control by faulting. A possible fault has been drawn in accordingly (Fig. 6). | j j Satsop Area i i i A second area, to the northwest of Cloquallum Creek, occurs principally in the valleys of the West and Middle 50 Forks of the Satsop River. It is the largest of the 3 areas mapped and forms an oval pattern elongated essentially ! i I 1 i jnorth-south extending for 17 miles beginning at a point 6 miles north of Montesano. For discussion, it is convenient I ito divide this into a southern portion (Ila) and a northern j I ; jportion (lib) (Fig. 7). j i Southern Portion i i i j ! Exposures are poor in the southern half, although they ! are better than in the Cloquallum Creek area. Along the j j southern boundary, the base was observed in a small gully j | | tributary to Black Creek in the NE 1/4 of section 24, T.18N, 1R.8W. At that point well indurated sma11-pebble conglomer- i I I late rests with angular unconformity upon tuffaceous, sandy I isiltstone of the Astoria Formation. The conglomerate con- Isists principally of well rounded clasts of altered basalt, j SThis is typical of conglomerate beds in the Montesano Forma tion throughout the Grays Harbor Basin. \ Although the basal contact was not followed in the i i jfield, a prominent topographic break can be traced east-west (and is thought to indicate the location of the base. To the i jeast in section 22, T.18N,R.7W, outcrops that are considered i |to be of the same conglomerate unit as described above occur 51 along a prominent cliff that descends to the north. The j conglomerate crosses the West Fork of the Satsop River in j j i jthe northwest corner of section 15. This basal contact, as I | j | . ; (determined by the writer, is 1 1/2 miles north of the loca- ; 1 ! ition given by Etherington (1931) and Weaver (1937). Both these authors give fossil locations in this "basal conglom- j erate" near the north end of Sylvia Lake about 1 mile north | i of Montesano. A search of the area failed to turn up the localities, possibly because they are now covered or were ’ |mislocated. The latter has possibilities for at least 2 j ! I ! i (reasons: (1) the conglomerate mentioned above fits the j i I (descriptions of Etherington and Weaver and none was found I iby this writer below it; and (2) throughout the area studied i j conglomerate beds occur frequently at or near the base of i | s Ithe Montesano. These beds are most persistent in the east- j j t i ern exposures. In addition, the contact presented in this paper approximates that indicated by Huntting, et al. I (1961.) . | The eastern border of area Ila is largely obscured by I ivegetation, alluvium, and the Satsop Formation. However, lone of the best exposures of the base of the Montesano I jFormation is present in a road cut at the south end of the bridge where the Middle Satsop Road crosses the Middle Fork of the Satsop River. At that point the Montesano rests with i jmarked unconformity upon the Lincoln Formation. Relief of I |more than 8 feet was developed on the underlying rock sur- i 1 ! jface before deposition of the conglomeratic sandstone of the Montesano Formation (Figs. 8 and 9). The burrows of various | jrock boring pelecypods, worms, and other marine organisms are numerous along the contact (Figs. 9, 10, and 11). These were first reported at this locality by Weaver (1937). The ] writer has observed similar borings at 5 other locations in i ' ! i [Grays Harbor Basin. They will be discussed later. Abundant sub-angular to rounded clasts, up to 4 feet across, of the j i ! Underlying formation are distributed throughout the basal ^sandstone of the Montesano Formation (Figs. 8 and 11). This ! i jWas observed not only at this outcrop but wherever the base ! i i i i I j (was clearly exposed. ! Along the western border of the lower Satsop area the base was observed in a road cut along Bitter Creek in the i i ! northwest corner of section 1., T.18N,R.8W. The Montesano j ! ! (Formation there rests with an angular discordance of more j S i than 30 degrees on carbonaceous mudstone of the Astoria | i ! i j iFormation. Elsewhere along this side the basal contact was | | (drawn by bracketing it between adjacent outcroppings. A i | (fault forms part of the contact west of Bitter Creek. i ___________________________________________________________________________ Fig. 8.— Sketch of the basal contact of the Montesano Formation in a road cut in the southeast corner of section 36, T.19N.,R.7W. Notice the large amount of relief and the jlarge rounded, mudstone clast enclosed in the overlying jsandstone. i i f e j ! s S ' i ' l ! I l i N S - i s f l i l l l i f e * |I ' ' S i I ! l j ! i / f f e t e i f S . i f ^ m e m / i i l l I i S s i ',7 I Fig. 9.— Photograph of part of the contact illustrated |in Figure 8. The hammer handle is 17 inches long. Arrows indicate pholad borings. 56 Montesano Formation Lincoln Formation Figure 9 I Fig. 10.— Photograph of a hand specimen displaying part of the contact in Figure 8 marked by abundant borings. The ruler gives the scale in inches and millimeters. 58 Figure 10 Pig. 11.— Photograph of a hand specimen of the contact shown in Figure 8. Notice the borings (B), carbonaceous debris (C), shell fragments (S), and rounded mudstone clast (M) . 60 Figure 11 •4* , 61 I Small faults interrupt the contact at several places (Fig. j 6). Mapping to date is not adequate enough to be certain I of the type of faulting and amount of movement involved. jwhere possible the relative movement is indicated on the Jgeologic map (Fig. 6). 1 ! | i | Limited structural control indicates a continuation | I I 'into the southern Satsop area of the east-west oriented, j i i westerly plunging syncline of the Cloquallum area. It will j i ' I be seen that this syncline can be traced westward into the ' jwishkah area and is therefore of major proportions. The j i jterm Still Creek Syncline will be used for it in this paper I (because the axial trace approximately coincides with the j paouth of Still Creek. To the north there is an abrupt i I ichange in the structural pattern to a consistent northerly I I ! istrike and easterly dip along the West Fork of the Satsop j 1 I River. It is probable that this change is primarily the |result of faulting; however, field evidence for proof of ithis is lacking. i I I iNorthern Portion I I i I | The northern Satsop area contains 4 of the strati- graphic sections measured in this study. These will be discussed in detail in later sections. The selection of 62 j these sites and the large amount of data subsequently ob- itained are a direct function of the better quality and high- i jer percentage of exposures than in any of the other areas. I I | : ! The base of the Montesano Formation is sharply defined I ion the Middle Fork of the Satsop River in the northeast i jcorner of section 1, T .2ON.,R.7W; on the Canyon River in the jnorthwest corner of section 2, T.20N.,R.7W; and on the West Fork of the Satsop River near the center of section 4, i jT.20N.,R.7W. This is the northernmost occurrence of the ! |formation. The Montesano is unconformable on the Lincoln ; jFormation on the Middle and West Forks of the Satsop River, j i i : ! and on the Astoria Formation on the Canyon River. The con- j itact is marked by local relief on the underlying formations ! at each of the localities. Evidence of boring molluscs, Iprobably pholads and related pelecypods, is abundant on the Canyon River and Middle Fork of the Satsop River. On the east and northwest the Montesano Formation is ' i ; j covered by extensive deposits of alluvium and the Satsop Formation. A small area of exposures is present along the I Wynoochee River in the vicinity of the abandoned Mobray i I iLookout. Although the base was not observed, sandstone j ! : I jconsidered to be not far above the base crops out on the ; i 1 . i IWynoochee. A fault along the south side of this latter are^ separates the Montesano from the Lincoln and Astoria Forma- ! jtions . The northern Satsop area grades into the southern por- j j tion. The consistent northerly strike and easterly dip along the West Fork of the Satsop River mentioned earlier ' I ; jforms the west limb of a broad, shallow, doubly plunging jsyncline that trends generally north-south. To the west there is a short paralleling anticline between the West Fork! jof the Satsop River and Wynoochee River. The upper Satsop syncline is interrupted by a large j i transverse fault that forms the southwest boundary of the j i area. For convenience it will be called the Mobray Fault since the projected trace passes a short distance south of j ! i ! ; piobray Lookout. Good control on this fault was obtained on i ! the Wynoochee River in the NW 1/4 of sectxon 36, T.20N., j P..8W.; on Carter Creek in the SW 1/4 of section 31, T.20N., j F..7W.; and on the West Fork of the Satsop River in the NW j 1/4 of section 4, T.19N.,R.7W. Offset of the Montesano formation indicates a left-lateral sense of movement. In i I view of the magnitude of offset involved, and the associated jdeformation along the fault zone, one would expect the j Mobray Fault to extend a considerable distance in either i jdirection from the area of positive location. A possible extension toward the northwest follows along the southwest flank of a ridge to the northeast of the West Fork of the Wishkah River in the northeast corner of T.20N.,R.9W. (Fig. I 6). Variable attitudes prevail where the projected course ; [crosses the East and Middle Forks of the Wishkah River . j [ | j [Also the southwest flank of the ridge mentioned above is I [straight and oriented in the direction of projection and [possesses a marked change in slope. Subtracting the offset j I ialong the fault would place the Crescent Basalt, that crops ' jout along the ridge, in the proper structural and strati- | graphic position in the open end of a large anticline j 'trending northwest-southeast across the Wynoochee River j (Fig. 6). The projection of the fault to the southeast is questionable, but an approximation is given. The orienta- Ition and sense of movement of this fault are similar to the i | ; I larger Calawah River fault zone along the north side of the [Olympic Mountains (Gower, 1960). Several smaller faults, some paralleling the Mobray Fault, were observed. I Wishkah Area I i i i ! A third major portion of outcrops of the Montesano Formation occurs along the western edge of the study area (Fig. 7). This too can be divided for convenience into a 65 ' southern portion in the vicinity of Aberdeen, Newskah Creek 1 and the lower part of the Wishkah River (Ilia); and a nor thern sector (Illb) along the 3 forks of the Wishkah River ; and part of the Wynoochee River. i j I jSouthern Portion j | i Area Ilia was the least carefully examined of those under study. The basal contact of the Montesano was not j i observed; but as in other areas reasonable control was obtained between outcrops. The formation rests unconform- j I jably upon mudstone of the Astoria Formation on Newskah Creekj I I ! | ;in the southeast 1/4 of section 32, T.17N.,R.9W. To the . i I north of Aberdeen the Montesano also overlies unconformably the Astoria Formation on the Wishkah River in the southwest i jl/4 of section 33, T.18N.,R.9W. Along the west side of the ientire mapped area Tertiary units are covered largely by : I ialluvium and the Satsop Formation. In this southern por- i :tion, outcrop patterns have been sketched in to demonstrate general relationships. Exposures of the Montesano Formation outline a shallow, westerly plunging syncline (the Newskah i Syncline) with an east-west axial trend (Fig. 6). On the | northeast the continuity of exposures is interrupted by a Ismail northeast-southwest trending fault. The distribution 66 | as presented in this paper is essentially the same as that given by Weaver (1937). Along the lower part of the Wishkah jRiver outcrops are scattered and their attitudes are vari- i jable. A tentative contact between the Montesano and Astoria I 'Formations is placed in the southwest 1/4 of section 21, | T .18N.,R.9W. I I 'Northern Portion ! : ! The northern sector of the Wishkah area (Illb) contains i ! jthe locations of 4 sections measured during this study. j I jWeaver (1944) implied that exposures in this area were the ! I i ; | ; most typical for the Montesano Formation. Along the north- j I 'east border the base is clearly defined on the West Fork of j I i ! 1 !the Wishkah River in the NW 1/4 of section 35, T .20N. ,R.9W. ; | : j Ion the Middle Fork in the SE 1/4 of section 36, T.20N., i R.9W.; and on the Wynoochee River in the NE 1/4 of section i i 28, T.19N.,R.8W. The basal contact is closely bracketed | | ! between outcrops on the East Fork of the Wishkah River in j j j the SE 1/4 of section 8, T.19N.,R.8W. At all these locali- ! ! j ities the Montesano rests with angular discordance on the j I ' ! Jinterbedded, carbonaceous mudstone, siltstone and sandstone ! I jof the Astoria Formation. The contact on the Middle Fork of the Wishkah is 3 miles north of that given by Weaver j (1937). On the southeast a northeast trending fault separ- I ates the Montesano and Astoria Formations. , ! The exposures in this area form a broad extension of ; i |the Still Creek Syncline. The plunge remains westerly. ! i : i | Weaver (1937) and Huntting, et _al. (1961) illustrate a con- : nection between areas Illb and Ila. All evidence from this : 1 ! atudy points toward a structural breach between them. | ! The Astoria and Lincoln Formations are highly folded : land faulted in the wedge shaped area between Illb and Ila I ' ; i !(Fig. 6). The Montesano, however, is only slightly de- j 1 I formed. Strikes are uniform and dips low, averaging 15 to j ! i | ! 120 degrees . j I i ! : I j Summary and Conclusions j I | | The Montesano Formation crops out in 3 major areas. frhese are from east to west: in the vicinity of Cloquallum j Creek; along the West and Middle Forks of the Satsop River; i and along the several branches of the Wishkah River. The j i jformation covers about 250 square miles (Fig. 6). ! A prominent unconformity, with a measured angular dis cordance of up to more than 30 degrees, separates the forma tion from underlying strata. The unconformity is marked by jlocal relief of more than 8 feet in the underlying rock, L_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 68 l i abundant borings made by several marine organisms, and littoral to sublittoral basal deposits of the Montesano ' I iFormation. Along the eastern side of Grays Harbor Basin thei | I Underlying unit is principally the Lincoln Formation. In I the western half of the area examined, the Montesano rests jupon various facies of the Astoria Formation. ; Two major patterns of folding are developed in the i ! Montesano Formation (Fig. 12). The broad, east-west trend ing Still Creek Syncline traverses the area from Cloquallum i ; i preek to the Wishkah River. Presumably it continues gener- ! 1 I ally westward beneath cover. Although interrupted, the ! i : | syncline has a gentle westerly plunge. The Newskah Syn- I i | cline, although smaller, is of a similar type. This east- | ! i West trend probably reflects major basement structural I I i I i i Control which maintained the Grays Harbor area as a signifi-j I pant sedimentary basin throughout most of the Tertiary. ’ j A second system of folds is oriented approximately j I i porth-south across the first. This is exemplified by the J j i Satsop Syncline and the anticlinal trends along the Wynoo- i chee River and the Middle Fork of the Satsop River. These s latter two interrupt the continuity of the Still Creek Syn- | j tline. Relationships are obscured along the Satsop River tut are demonstrated clearly on the Wynoochee. The broad Fig. 12.— Map illustrating major structural features developed in the Montesano Formation. i 70 I ♦ / « C H t f U L I t newskah syncline SYNCLINAL AXIS SH0WIN0 DIRECTION OF PLUNOE ANTICLINAL AXIS FAULT TRACE SHOWING OIRECTION OF RELATIVE MOVEMENT < M t L tW H B o a pm u nc « l M ONTESANO FORMATION s o 1 0 STATUTE M ILES FISURE 12 ' w u " anticlinal fold developed there in the Montesano Formation is located over similar folds in the underlying units. I ; ; i ^Immediately west of Montesano there is a structure, locally ; i ! jCalled the Melbourne Anticline, developed in the Astoria i I [Formation. This fold is of the same general size as that jin the Montesano to the north. What is more, their axial I [traces coincide approximately. The Melbourne Anticline is i jconsidered, therefore, to be largely the result of post- I Montesano deformation. Northward along the Wynoochee anticlinal trend, struc- i jtural developments below the Montesano Formation become morej j ! Icomplex and more intense. Several faulted folds developed j in the Astoria and Lincoln Formations occur between areas | Illb and lib. These are oriented northwest-southeast to ! ! I horth-south. This trend has been considered typical of i Tertiary structure in general in southwestern Washington i : ' i ; | '(Weaver, 1937; Snavely and Wagner, 1963). j J ! The north-south post-Montesano structural trends are j j I therefore related to pre-Montesano patterns. As one ap proaches more permanent positive areas, such as the Olympic i 1 Mountains, structure beneath the Montesano Formation becomes! j : progressively more strongly developed. In the centers of j ! I jnajor basins, such as the Grays Harbor Basin, however, there! 72 | j may have been little or no pre-Montesano deformation. ! i Faults cutting the Montesano Formation follow two gen eral trends. One set is oriented northwest-southeast and i ! jthe other northeast-southwest. Much of the faulting is in- | i ' j | jferred in order to explain outcrop patterns. However, the j jMobray Fault is of major significance. It cuts transverse- ! ly, northwest-southeast across the northern part of the study area. Its size and left-lateral off-set indicate a i j I possible relationship to the larger Calawah River fault zonej i along the north side of the Olympic Mountains. Physical Stratigraphy I General Orientation Eight stratigraphic sections of the Montesano Formation i ■were carefully measured and sampled (Fig. 13). Four of j these are in the Wishkah area and 4 in the northern Satsop i (area. These 8 sections contain a total footage of 18,540 i I jfeet. i ! | Original intentions were to obtain detailed sections on all sides of the areas of exposures. However, the lack of outcrops and high degree of weathering in the southern and eastern portions proved the plan to be unrealistic. i I Fig. 13.— Locations of measured sections 74 FIGURE 3 3 FIGURE^ 4 2 FIGURE 4 4 £ FIGURE 14 FIGURE 2 4 FIGUi K ✓. > * J FIGURE .2 9;.' V ELMA M O N T E S A N O A B ER D EE N IS h L tg tn d On S T A T U T E M IL E S Therefore, detailed discussions will be limited to the northern areas where exposures are numerous and fresh. i Other areas, particularly along Newskah Creek, will be out-! i | lined briefly. I i ! 1 | Since several sections display considerable similarity,] j ! typical ones for each group will be treated thoroughly and jthe others used for supplementary control. Areas will be i ! i jexamined in order from west to east rn the manner that de- ; I 1 j 'position would have taken place in a transgressing sea. A 1 i ! proposed type section will be discussed first. j j Type Section j i I i i ! j Sections of the Montesano Formation measured along the West, Middle, and East Forks of the Wishkah River and the I iWynoochee River (Fig. 13) are the thickest, most fossili- j j jferous, and in general most varied of all those studied. ] ' i I It is indeed unfortunate that Weaver first studied the unit I in the area north of Montesano and named it for that town, j ifor there the formation is only partially represented and i i jexposures are poor. The name of a formation suggests a type! ! iarea. Article 131 of the Code of Stratigraphic Nomenclature: i | (American Commission on Stratigraphic Nomenclature, 1916) I 1 Istates: "Thus the type locality contains the type section 76 and the type area contains the type locality." One might then argue that a type section for the Montesano Formation i Imust be in the area originally referred to by Weaver (1912),1 even though he did not designate a type section. The vagueness of his locality descriptions, the poor quality of {exposures, and the subsequent findings that little of the formation has been preserved for a considerable distance north of Montesano all make such a requirement serve little ; luseful purpose. i i i j j The only published measured section that has been re- j jferred to the Montesano Formation was that of Weaver (1916) j ialong the Middle Fork of the Wishkah River; however, still ; no mention was made of a type section. It was pointed out {earlier in this report that Weaver, in his account of the I jgeology of that section, included a variety of unrelated units. Nevertheless, he did include strata which fit his definition of the formation. Also, Weaver (1944) made reference to the Montesano Formation as being a composite |of sections along the Wishkah and Wynoochee Rivers. With ] Ithis in mind, it is considered necessary that a type sec tion be selected and described from the Wishkah area. i i ! ! Although portions of the column are better represented |in other sections in this area, the entire formation is best 77 I exposed and least disturbed along the Middle Fork of the Wishkah River (Figs. 13 and 14). Exposures along this stream from a point 2,100 feet west and 1,400 feet north of , j the southeast corner of section 36, T .20N.,R.9W., to a point |600 feet east and 1,300 feet south of the northwest corner | i iof section 12, T .19N.,R.9W., are here designated the type section of the Montesano Formation. i The basal contact of the formation is clearly exposed in the southeast 1/4 of section 36. It can be traced for i i ; jabout 750 feet in steep cliffs along the southwest bank of |the river (Fig. 15). To the southeast the contact is ob- j Iscured by vegetation and terrace gravels. To the northwest ! i ' i I it is covered by alluvium and slide debris at a point where ! j _ | ithe river turns sharply to the south. The base is again j I jvisible across the stream in a cliff bordering the west side of a small gully tributary to the main stream. On the Middle Fork of the Wishkah the Montesano rests I j junconformably upon massive to thinly bedded., dark olive i gray, fine- to very fine-grained sandstone and interbedded mudstone of the Astoria Formation. The sandstone often jcontains a large percentage of silt and clay. The Astoria j i |is abundantly fossiliferous with both foraminifera and I jlarger invertebrate remains. A well preserved, distinctive | Fig. 14.— Station locations, Middle Fork, Wishkah iRiver . 79 STATION LOCATIONS WISHKAH RIVER TRAVERSE *T>jL / B A S E O F M O N T E S A N O FO R M A T IO N A ST O R IA r8 ^ ' V — y .FORM ATION ^ IOOO SA TSO P FORMATION 2 0 0 0 F E E T WK I SA M PLE LOCATION ^ < f o R E L IA B L E A TT ITU D E ^ ^ 2 0 FAIRLY R E L IA B L E A T T IT U D E ^ < 2 0 U N R E L IA B L E A T T IT U D E — FO R M A T IO N C O N TA CT (D A S H E D W H E R E A P P R O X IM A T E ) F IG U R E 14 B. A. F M L I I IB Fig. 15.— Photograph of the base of the Montesano For mation on the Middle Fork, Wishkah River about 100 feet east of WK-1. Viewer is looking southeast. / Figure 15 Astoria Montesano Formation Formation oo 82 foraminifera fauna from the Astoria just below the base of the Montesano correlates well with faunas from the Relizian Stage of California (Kleinpell, 1938). The following list contains dominant species of the fauna. Bolivina brevior 17% Bolivina advena advena 14% Bolivina advena striatella 14% Uviaerina suboereqrina 13% Buliminella californica 11% Uviaerinella californica ornata 10% Globigerina concinna 7% Cassidulina minuta 3% Buliminella eleaantissima 2% Bagqina californica 2% Comparison with modern assemblages indicates that water jdepths at the time of deposition ranged from 650 to 1,000 I I ! j ifeet. i At the immediate contact in this type section, there is angular discordance of only about 5 degrees between the (Astoria and Montesano Formations. Upstream, however, strata. i (of the Astoria display strong folding, probably associated with faulting. The Montesano, on the other hand, possesses I remarkably uniform attitudes throughout the section. Prior to the deposition of the Montesano Formation an erosion surface with nearly 1 foot of relief was developed on the underlying rock (Fig. 16). Rounded to sub-angular blocks of the Astoria Formation up to 7 inches across are / Fig. 16.— Sketch of a portion of the basal contact ex posed about 300 feet to the northwest of WK-1. Notice con glomerate lenses, relief, borings, and shale clasts. 0 L i o J F E E T VERTI CAL 2X F IG U R E 16 « . A. F O W L E R , 1*9 5 00 85 i common inclusions in the basal few feet of the overlying i sandstone. The contact is marked by the borings of various j ! marine organisms, principally pelecypods. These burrows j ! reach a length of up to 15 inches and a diameter at the j I bottom of 3 inches (Fig. 17). Well preserved molds of the | I j animals are frequent in the borings (Fig. 18). Lenses of I small-pebble conglomerate up to 5 feet thick are irregularly i distributed along the contact. The thicker units lense out ; in about 10 feet in either direction parallel to the strike.! Associated with the conglomerate and sandstone are abundant,! commonly fragmentary shells of Spisula and Chione plus car- ! I bonized wood fragments. j i i : | A total thickness of 2,490 feet was measured on the j Middle Fork of the Wishkah River. In the northern Wishkah j area the formation is easily divisible into a lower member i i i _ i jof sandstone and a finer-grained, upper member (Fig. 19). i ! The upper member is 1,030 feet thick as exposed, and the lower member is 1,460 feet thick. The fine-grained member is rather uniform in lithology; however, the lower member displays numerous local variations. It can be divided into 5 rather well defined units. Lowermost (unit 1, Fig. 19) is 60 feet of fine-to medium-grained sandstone (Fig. 20). lit is fairly well sorted and easily friable. Although the Fig. 17.— Photograph of a large boring at the contact shown in Figure 16. Hammer handle is 17 inches long. Fig. 18.— Photograph of an external mold of Zirfaea (?) sp. at the contact shown in Figure 16. The knife is inches long. 89 Figure 18 Fig. 19.— Columnar section of the Montesano Formation, measured along the Middle Fork of the Wishkah River. MIDDLE FORK, WISHKAH RIVER SECTION (A u S u < 0 PLIO- PLEIST. UJ z UJ o o as ui hi X a : UJ a . o. D § SCALE q 0) 0 100_____ 800 LI Ll FEET u X § COVERED sj t. _^ =r—■ ' rr^jrrr^z rrrj. COVERED (0 r T T ^ - . T T S i ^ T r s i v / T S i V . n l S '. v s K rrr^E ra^rrrr^ns r m m rr— J COVERED______ COVEPfiO _____ COVERED E ± ± ^ e i COVERED COVERED IO m ro 0> IO I II . j U I s ! ® • * IS 8 P — 37 —36 -35 --it 28 ~27o* 26 -25 —24 SLIGHT ANGULAR UNCONFORMITY L E 6 E N 0 ryr-r-i MUDSTONE TUFFACEOUS MUDSTONE CLAYEY SILTSTONE UJ z UJ e o < <o UJ ec UJ a. CL 3 q: uj a. Q. £C UJ £ o IO COVERED COVERED i . » 1 covEPno COVERED COVERED ro a> ro COVERED V “ - 5---- . ~ : T ^ T " r r ^ - ; . ' ; V - ^ 7 7 7 . - ; . J~— — — o (D "CM' ■ : . W? ■ ; A i : : - t Ht ■;•^-il?: ) H COVERED ro -28 ---26 -25 -24 -23 —22 -----21 -20 — 19 — 18 — 17 -16 ■T4 — 13 — 12 -I I ■HO L E G E N D • ■ • ' O V o v ; : m m MUDSTONE TUFFACEOUS MUDSTONE CLAYEY SILTSTONE SILTSTONE SANDY SILTSTONE SILTY AND/OR CLAYEY SANDSTONE SANDSTONE CROSS-BEDDED SANDSTONE CONGLOMERATIC ( PEBBLY) SANDSTONE CONGLOMERATE CALCAREOUS CONCRETIONS IN SANDSTONE (ETC.) m F10URE Ui H X UJ Q. £L 3 LOWER MIOCENE x UJ * o _j ASTORIA . . . l \ ■ .— r - '. \ : .’-7 7 .' V : : • ' . • ■ : . : : . ’ V K : ' 7 r > ' . : • ; . ■ Y , r i > v ; • • ■ ’ •''-^2 : T T yy ro COVERED ■ : • : . - r ; ■ , • , i \ . ' . ■ . • T Trr r r . . COVERED : •: •: • .:: -• '■ •-• ■ • *;: * . v . • ' . - tH - . ^ t . : • COVERED i i j S s S ; I / V 00 N — 19 , w t o K-- o <0 i\r ro N s - 00- (O 10 ’ ■(»' (0 — 18 — 17 -16 H 4 — 13 — 12 --! I ■HO — 7 TTTi. m j 1 1 1 W k . m m . / O o r j /> r s 9Anui 9iUioivnc. SILTY AND/OR CLAYEY SANDSTONE SANDSTONE CROSS-BEDDED SANDSTONE CONGLOMERATIC ( PEBBLY) SANDSTONE CONGLOMERATE CALCAREOUS CONCRETIONS IN SANDSTONE (ETC.) LIMESTONE CONCRETIONS MOLLUSC SHELLS CONVOLUTE STRUCTURES LAMINATED BEDDING THIS L E 0E N 0 A PPLIES TO ALL THE COLUMNAR SECTIONS IN THIS REPORT. NO ONE SECTION NECESSARILY CONTAINS ALL OP THE SY M BO LS. TOTAL THICKNESS - S4B0 FEET M 19 0. A. FO U LER, IS M Fig. 20.— Photograph of the basal sandstone unit at jstation WK-2 on the Middle Fork, Wishkah River (see Figs. 14 and 19). ! 94 i j I jsandstone is generally massive, lenticular, calcareous sand- istone concretions serve to define bedding planes. In cross section the concretions measure up to 1 foot thick by sev- i eral feet long. These, with more irregularly distributed spherical forms, are frequent throughout the lower member. ; i Differential weathering and erosion associated with zones of more abundant silt and clay sized particles also tend to ; outline bedding. Well rounded, granule- to small pebble- Isized clasts make up 1 to 2 per cent of unit 1. They are both bedded and randomly distributed. Fragmental mollusc shells and carbonized wood fragments are common. When fresl} the sandstone is light gray to bluish and greenish gray. i With oxidations the color changes through olive gray to i orange and brown. This is typical of sandstone throughout the Montesano. | The general composition of sandstone from the Montesano [ Formation in the Wishkah area is rather typical for the | i entire Grays Harbor Basin. Certainly small variations j exist areally and stratigraphically; however, detailed pet- | i ! rographic analyses are beyond the scope of this project. ! j i i Most of the sandstone in the formation would be classed as j I I isubfeldspathic lithic arenite following the scheme of Williams, Turner, and Gilbert (1954). The major components |in decreasing order of abundance are: (1) quartz, (2) rock i jfragments (principally altered basalt), and (3) feldspar (chiefly plagioclase). Epidote, hornblende, biotite, gar net, zircon, and magnetite make up the accessory suite. Lithologically, sandstone of the Montesano Formation is for practical purposes indistinguishable from that of the Astor ia Formation as described by Pease and Hoover (1957) and i ; jSnavely, et _al. (1958) and as observed by this writer. Unit 2, above unit 1, is composed of 70 feet of mas- ;sive, compact, carbonaceous and micaceous, sandy siltstone. ; The percentage of sand increases to dominance toward the underlying and overlying units. It is most commonly uni formly disseminated but does occur in thin beds. Clay sized material is concentrated in the lower third of the interval.; i Carbonized wood fragments several inches across are abundant in an 11 inch thick zone near the base of the unit. Mol luscs, foraminifera, and miscellaneous worm burrows are ; l abundant throughout the siltstone. The color is olive gray ; even on the freshest surfaces. Such is the case for all Ifiner-grained units in the formation. ; | j i Unit 3 is similar in all respects to the basal unit. ! ^Although 29 per cent of the total thickness of 37 0 feet is j I Icovered, the remaining portion is remarkably uniform. Small] pebble-sized clasts approach 5 per cent by volume of the j ; jtop 1/4 of the unit. They occur in thin, discontinuous beds 1 ' ;and as disseminated particles. Five feet below the top is j 1 a bed of sandy, small-pebble conglomerate 3 feet thick. ■ 1 ; Well over 50 per cent of the clasts are altered basalt similar to that of the Crescent Formation. This is typical : of the composition of all Montesano conglomerate. Burrows, j possibly left by marine worms, are fairly common and are ! larger than those from lower units. They reach a maximum diameter of about 1 inch and several inches to more than 1 j foot long. | | ! The next unit, number 4, is 170 feet thick. Available , exposures contain siltstone like that in unit 2. Unfortu- j ; l nately, 140 feet of this portion of the section is covered. ! The topmost unit of the lower member (unit 5, Fig. 19) j is composed of 790 feet of massive to thin-bedded, silty, 1 1 very fine- to fine-grained sandstone (Fig. 21). Because of : i the cementing properties of the silt and clay present, the j 1 ! sandstone is only slightly friable. The unit contains 5 to j 10 per cent mudstone in thin, irregular beds. Sorting is j good locally but more commonly is poorly developed in the isandstone of this unit. Flakes of carbonaceous debris and mica are abundant in places, particularly on surfaces Fig. 21.— Photograph of a portion of lithologic unit 5 | jof the lower member of the Montesano Formation at station iWK-20, Middle Fork, Wishkah River. Hammer handle is 17 i inches long. ! i 98 Figure 21 ibetween laminae. Mollusc remains are rather common through- ! jout this unit; however, foraminifera are rare. "Worm" bur rows of varying sizes and shapes are more frequent than in any of the previous units. No conglomeratic material was observed in this part of the section. Two only vaguely distinguishable units comprise the :upper 1,030 feet of the Montesano Formation in this area. The lower 800 feet (unit 6, Fig. 19) are made up of massive mudstone with a characteristic blocky fracture pattern (Fig. 22). Overlying this are 230 feet of massive to poorly- bedded, sandy siltstone (Fig. 23). This latter contains a large enough fraction of very fine-grained sand to consider it in places a silty sandstone. The ease with which this fine-grained sediment is weathered and eroded has resulted in only 55 per cent exposure. The upper member is tuffa- ceous throughout; however, volcanic glass shards are most abundant in the upper third. Finely divided carbonaceous i debris is abundant locally. Molluscan fossils occur fre- j Iquently and foraminifera are more abundant and varied than I ! i in any other portion of the Montesano. Concretions common to the lower member are conspicuously absent in the upper. : I i The lithology of both units of the upper member is a rather uniform light olive gray to olive gray in color. The I Fig. 22.— Photograph of a portion of unit 6 of the jupper member at station WK-33, Middle Fork, Wishkah River. Notice the blocky fracture pattern which is typical of this unit. Hammer handle is 17 inches long. I 101 Figure 22 Fig. 23.— Photograph of unit 7 at station WK-38, Mid dle Fork, Wishkah River. Hammer handle is 17 inches long (slightly below center in the photograph). \ i 103 Figure 23 104 | contact between the 2 members is gradational; but the grada tion takes place rather abruptly. i i The top of the Montesano Formation is not present on j ; | the Middle Fork of the Wishkah River nor is it on any of j the sections in the Wishkah area. The highest exposed beds, in each case, are truncated by an erosion surface. A series of loosely consolidated conglomerate, sandstone, and silt stone has been deposited upon this surface. These capping beds are universally deeply oxidized; they are commonly re ferred to as the Satsop Formation. j Reference Sections i I I Northern Wishkah Area j foishkah River f West Fork ! The lower member of the Montesano Formation is best i i i i represented in the measured section along the West Fork of ! I the Wishkah River in the Northern Wishkah area (Figs. 24 and 25). Along that traverse less than 5 per cent of the total thickness of 1,570 feet is covered. In general, the same sequence of lithologic units is displayed on the West !Fork as was described for the Middle Fork. The Montesano Formation rests with angular discordance Fig. 24.— Station locations for the West Fork, Wishkah River section. 106 STATION L O C A T IO N S W E S T F O R K W IS H K A H R IV E R T R A V E R S E ASTORIA FORMATION BAftE O F MONTESANO FORMATION A N 4 * WWK > yrf /'3, 4 000 S A T S O P FORMATION 2 0 0 0 F E E T WWK I S A M P L E LOCATION R E L IA B L E ATTITUDE ^ 2 7 FAIRLY R E L IA B L E ATTITUDE ^ < 2 5 U N R E L IA B L E ATTITUDE "■ FORMATION CONTACT F IG U R E 2 4 B. A. FOWLER IMI Fig. 25.— Columnar section of the Montesano Formation I [measured along the West Fork of the Wishkah River. FLIO-PLEISTOCENE SEWES WEST FORK WISHKAH RIVER SECTION CO p UJ ui Z u SCALE 100 o m 200 FEET EXACT CONTACT COVERED COVERED E" 30 COVERED 29 28 27 26 COVERED 25 24 23 COVERED COVERED COVERED COVERED COVERED THICKNESSES ABOVE THIS HORIZON ARE SUBJECT TO CONSIDERABLE QUESTION COVERED FIGURE 25 ' 1 5 4 ; 20 5 1 91 157 106 9 2 ,89 74 , 2 87 16 17 16 — 15 14 - - 13 12 I I 10 9 8 7 6 5 4 3 2 — TOTAL THICKNESS * 2 8 1 0 F E E T I FOR L E G E N D S E E F IG U R E 19 ) G A. FOW LER, 1968 108 109 ! jupon the Astoria Formation as described on the Middle Fork. ;tion about 1 1/2 miles upstream, but only a sparse assem- bathyal species are given in the following list. Bolivina marginata pisciformis Bulimina inf lata allicrata Cvclammina sp. Epistominella relizensis Gyroidina soldanii cristobalensis Nonion pompilioides Plectofrondicularia miocenica Sphaeroidina variabilis Suggrunda eckisi These suggest a correlation with the Upper Saucesian of j j California. Water depth during deposition of this material I is estimated at 3,300 to 5,000 feet. This is in marked j 'contrast to the littoral and inner sublittoral environments ! j indicated by the fauna and sediment of the basal Montesano deposits at this locality. Abundant borings made by marine organisms mark the j contact (Fig. 26). These borings are filled with the fine grained sand of unit 1. Although twice as thick in this the Middle Fork. Well preserved mollusc remains are fre quent throughout the unit. In fact, megafossils are better Excellent faunas were obtained from this underlying forma- blage was found immediately below the contact. Distinctive \ section, it is in most respects similar to the basal unit represented in this member on the West Fork of the Wishkah I I j Fig. 26.— Photograph of the contact between the Monte- ; isano and Astoria Formations, West Fork, Wishkah River. \ Notice the numerous filled pholad borings. Tip of the knife 'blade is at the contact. Knife is 6 inches long. Figure 26 |than in any other portion of the formation studied. Ten I jfeet above the base is a 1-foot-thick concretionary zone of .shells, small pebbles, and carbonized wood fragments. One i jof the latter is thoroughly riddled with borings similar to those made by Teredo. A second such bed occurs 15 feet jbelow the top of the unit. Units 2 and 3 are not well defined on the West Fork. jTheir characteristics, however, are generally the same as idescribed previously. The lower siItstone is 300 feet thick and the overlying sandstone 27 0 feet. These thick- i nesses are 7 0 and 37 0 feet, respectively, on the Middle j ! i Fork. Of note is the presence of gentle cross-bedding in the sandstone in this section. This was not observed on ! i , t ’ the Middle Fork but is a locally common feature of Monte- ; I I isano sandstone in the Grays Harbor Basin. About midway > through unit 3 is an interval 30 feet thick of small-pebble ; ; conglomerate beds with shell debris and interbedded sand- j stone. j ; ; Little comment need be made of units 4 and 5 in this j 'section. They are of the same order of thickness as on the i Middle Fork and of completely similar lithology. The upper member of the Montesano Formation along the jWest Fork of the Wishkah River is about 50 per cent covered. ! 113 I I 1 |Most of the exposed strata are deeply weathered. It was I inot possible to obtain any reliable attitudes throughout : i jthis part of the traverse. For these reasons, the measured j thickness of 1,230 feet can only be considered an approxi mation. In general, there is no difference between the ' lithology here and on the Middle Fork. I ; Although the actual contact was not observed, the highH I I jest exposed portion of the Montesano Formation is unconform- lably overlain by deposits of the Satsop Formation. The : j latter covers most of the Wishkah area. jWishkah River. East Fork Of the measured sections in the Wishkah area, the one 1 ! along the East Fork is least well exposed (Figs. 27 and 28).! ■ i Forty-three per cent is covered. Despite the cover, the | 2 members of the formation are well defined. There is j j little evidence, however, of the units recognized in the 2 j j previous sections, particularly in the lower member. The basal contact is covered but can be located with j llittle question between adjacent outcrops and by using topo- i ; graphy. Basal sandstone of the Montesano Formation at this j point apparently rests with considerable angular unconform ity upon mudstone and sandstone of the Astoria Formation. Fig. 27.— Station locations, East Fork, Wishkah River. 115 STATION L O C A T IO N S E A S T F O R K W IS H K A H R IV E R T R A V E R S E ASTORIA FORMATION EW K I 2 3 2 4 IOOO 2 0 0 0 F E E T 1000 SATSOP FORMATION EWK I SAMPLE LOCATION ^ < |8 R ELIA B LE ATTITUDE y <25 FAIRLY RELIABLE ATTITUDE — — FORMATION CONTACT, APPROXIMATE FIGURE 27 • . A. F O W IM t* M Fig. 28.— Columnar section of the Montesano Formation [measured along the East Fork of the Wishkah River. EAST FORK, WISHKAH RIVER CO UJ <E bi (A PLIO- PLEIST. UJ o O z o < 3E K O u. < (0 o: u i AD s ui SCALE 100 200 F E E T CO t o ll! K z w Xu! 2 * oc UJ Q . CL z> — 7 — C O V E R E D ' C O V E R ED COVERED C OVERED COVERED COVERED C O V E R ED C O VE RED o o o o ) - 40- 40 ) IO ).A . IO o i - -8 - O CM CM IO CO U K " - J 111 CL AO ' ssg O u c o z ~ -17 16 15 -14 -13 -12 - I I -10 SECTION EXACT CONTACT NOT O M E R V E D FIGURE UJ CL Q. 3 LOWER MIOCENE o> UJ az Ui £ “ : -.ST v: r r t:/S T T -: rH : “ vr COVERED « . r . . O ’ . * * i i £ « s s ® s ’. t v . * . • COVERED COVERED . v ■ r . : . ' i i - « l ? n ■ S lip ; » : ’ ■ ' ■ ’ • < • • • ~ > . ' i ' » ^ . » . -. ' v ' . • ; ■ ' . • ' ■ • .*.*. . . . . . t t .’i . ; v ASTORIA in GO O K CM CM O CM — 8 — 7 — 5 EXACT C ONTACT NOT O S S E R V E D TOTAL T H IC K N E S S • E S S O F E E T (F O R LESEHO SEE FISURE I S ) 28 S. A. FOWLER, IM S 117 I 118 j | I Folded and faulted strata of the latter crop out a short distance upstream from the stratigraphieslly lowest outcrop ; jof the Montesano. The Montesano Formation, on the other j i | !hand, is not involved in structural complexity throughout j t ; jthis part of the area. j ! The lower member along the East Fork is about 1,500 I ! jfeet thick and is composed principally of sandstone and j jconglomerate. The lowermost 650 feet possibly represent ; i junits 1 through 3 described in the other sections. Fine- | j ; |to medium-grained sandstone is dominant through this inter- j I I jval. Except for the coarser grain size the lithology is j I i j ] ithe same as that in units 1 and 3 on the Middle and West i : | Forks. Unit 2 is missing. Thin, pebble conglomerate beds j | j |and disseminated clasts appear near the middle of the inter- ! ival. Percentage of conglomerate increases up section to a | i i jnaximum of 45 per cent in the upper 100 feet. At that point i !>eds are as much as 10 feet thick. Beds of shell debris and imudstone with leaf remains are common in the upper third of j !the interval. | | The upper 850 feet of the lower member is quite similar j jto unit 5 of the other sections. Unfortunately, only 25 I I jper cent of this interval is exposed. No evidence was found ! jfor unit 4. It is quite possible that one of the covered 119 portions near the bottom of the interval represents that unit. | About 850 feet of the upper member was measured on the ! i # . |East Pork of the Wishkah. A little less than 1/2 is ex- j | Jposed. The portion that is visible, however, is in most I I jrespects identical to the lithology of the upper member ! i I ! throughout the Wishkah area. Sandstone, interfingering with the lower member, is well displayed near the base (station EWK9, Fig. 28). j | iWynoochee River I I ! The section measured down a portion of the Wynoochee jRiver is a composite of somewhat isolated segments from both sides of the valley (Fig. 29). It was necessary to j [project relationships up to a third of a mile. Some por tions of the section were examined in road cuts and others in stream banks. Between these relatively well exposed j jsegments were small outcrops in areas covered by dense vege tation. It became necessary to estimate thickness in spots. [No reliable attitudes were taken in the upper 1,000 feet of i ! [section. For these reasons, relationships between units anc. 1 i [the total measured thickness of 2,600 feet are subject to | [considerable question. Regardless of this, the general r ~ ~ " i Fig. 29.— Station locations, Wynoochee River. i 121 STATION LOCATIONS WYNOOCHEE RIVER T R A V E R S E BASE OF THE MONTESANO FORMATION A II 4 * A 13 a 14 WY I 4,5 8 6 ASTORIA FORMATION 31 a 32 \ J J 8£<15 I ^>^12 WY I SAMPLE LOCATION ^<T6 RELIABLE ATTITUDE ^8 FAIRLY RELIABLE ATTITUDE ^<1 UNRELIABLE ATTITUDE — FORMATION CONTACT (DASHED WHERE APPROXIMATE) 5000 FEET FIGURE 29 9 . A. FO W LE R , I9 6 0 122 trends displayed and relative thicknesses are valid. j As in other sections, 2 distinct members are present j (Fig. 30). The lower is about 1,700 feet thick and the upper measures on the order of 900 feet. Approximately 65 iper cent of the formation is exposed. The distinctive ! jlithologic units reported from the West and Middle Forks of I I | the Wishkah River are even less recognizable here than on j I the East Fork of the Wishkah. ! ' ! Basal sandstone of the Montesano Formation on the Wy- I I inoochee River rests with an angular discordance of 30 de- j I i | i jgrees on massive foraminiferal mudstone of the Astoria. A j | 'well preserved fauna from the latter indicates a Saucesian ; i ;to perhaps Relizian age. The dominant elements are given jin the following list. I Bolivina advena striatella Epistominella carinata parva Nonionella boueana costifera Bulimine11a californica Uviaerinella californica ornata | Buccella vicksburaensis Siphoaenerina transversa Plectofrondicularia miocenica Bulimina montereyana This assemblage is indicative of the upper bathyal environ ment . | i The lower 140 feet of the Montesano Formation is a i massive sandstone unit like that previously described. It Fig. 30.— Columnar section of the Montesano Formation measured along the Wynoochee River. i WYNOOCHEE RIVER SECTION SE R IE S FORMATION MEMBER LITHOLOOIC UNITS K UJ 0. £L D UI Z UJ o 9 _ o f 2 O Z S C A L E O____100 200 F E E T _ COVERED COVERED COVERED UI ki Z COVERED — j.jo. i-io- b--- COVERED COVERED COVERED )- o ft IO o ft IO o o hi “■ -32 -31 ----27 -24 : S “ — 21 -20 -19 — 18 APPROXIMATE SYNCLINAL AXIS POOR CONTROL BETW EEN SEC TIO N S ABOVE AND BELOW TH IS POINT 3 UJ z UJ o o _ o r - s O z < «* 0) , " UJ • 1- z AC o ■ , UJ 2 K Q. UJ 0. * 3 O 10 - J COVERED COVERED - : r r r .- ; v. rrrtj COVERED COVERED COVERED COVERED COVERED COVERED — 20 “ 19 o IO ro — 18 O O * ’-40- - ‘.'1 f —— —■ ““ -12 — I I S 10 !2 04 -10 -9 -8 10 CVJ f----- 7 UJ Q. CL 3 LOWER MIOCENE z o 2 or UJ $ o -j 10 C V J ASTORIA COVERED COVERED COVERED COVERED \ ■ " ■ '; , 'C ^ B f c ‘O O '* ; (i>'• ' f j l . ! j ■ > ' A * m ’ l H CbVERED . ___ * v . i a l • » : * * V > * * . . ' • * ) • . * ; ' f £* ^.ttA^/cS.V £» v^'.^pkW dai i R a i ^ f c f l FIGURE 9 0 10 -9 -8 -7 45 3 2 J ESTIMATED TOTAL THICKNESS ■ ESOO FEET { FOR LE 8E N 0 SEE FISURE IS ) H ro «. A. FOWLER. ISS8 125 j i rests on a contact surface characterized by small scale j relief features and borings of various marine organisms. j I jFragments of the Astoria Formation are included in the basal. jpart of this sandstone unit. I ! | Overlying the basal sandstone is 200 feet of section j | I I i 'Composed of about 50 per cent pebble conglomerate and sandy j ! conglomerate, 40 per cent sandstone, and 10 per cent mud- j j i jstone. The latter occurs as thin, irregular beds. Con- j i i I | glomerate beds reach a maximum thickness of 25 feet. These ! ibeds thin rapidly and lense out both down dip and parallel I ! ^ ! i ! ito the strike. Plant debris is locally abundant and molluscj i shells are present. ! The next approximately 700 feet of the formation is I made up of sandstone like the basal unit with 5 to 10 per cent thin, discontinuous, pebble conglomerate beds and I [disseminated clasts. It is quite uniform throughout. Few ! imollusc remains or other fossils were observed. "Worm" I I I burrows approximately 1 inch in diameter and up to 2 feet ! j long are common. Following the latter sandstone is a unit about 700 I feet thick of silty, very fine-grained sandstone. The few exposures available for study indicate this interval is the same as unit 5 of the previously described sections. No 126 conglomerate was observed. Mollusc shells are common; j i j foraminifera and various "worm" burrows are locally abun- I jdant. The latter are so abundant in an interval 100 feet thick, near the middle of the unit, that they impart a pecu liar, mottled appearance to the rock, particularly when i ! weathered (Fig. 31). \ \ s I i The upper member of the Montesano Formation on the Wynoochee River has been determined to be about 900 feet [thick. It is, in general, quite typically represented. : | i jThe most significant point of departure is in the higher I [percentage of very fine-grained sand and silt than in the ! other sections of this area. jSummary I i I ! In the northern Wishkah area the Montesano Formation j 'has been divided into 2 members. The lower member is com- Iposed predominantly of fine-grained sandstone with pebble conglomerate and mudstone locally dominant. Measured thick ness varies from 1,700 feet on the Wynoochee River to 1,460 feet on the Middle Fork of the Wishkah. The computed aver age is 1,560 feet. In view of the problems involved in jmeasuring sections in the Grays Harbor area, 1,500 feet is [the most realistic figure to use. Fig. 31.— Photograph of abundant "worm" burrows in the Montesano Formation at station WY-16 on the Wynoochee River Notice the peculiar mottled appearance of the rock when weathered. 128 i ! Figure 31 129 Five rather distinct lithologic units are recognized in the lower member in the western part of this area. They , I are, in order from the base up: (1) sandstone, (2) mud- j i stone, (3) sandstone, (4) sandy mudstone, and (5) silty | | jsandstone. In the eastern part only 2 can be delimited: ; ! i [ ! |(1) conglomeratic sandstone and (2) silty sandstone. Goingj i i from northwest to southeast the mudstone units progressive ly drop out (Fig. 32). In other words, the sandstone to ' i shale ratio (SS/SH) increases toward the southeast. For 1 I ' any one section this ratio decreases upsection. In like I j j [fashion, the percentage of conglomerate increases toward ! i ! ;the southeast. i Determinations of the thickness of the upper member vary from 1,230 feet on the West Fork of the Wishkah River to 850 feet on the East Fork. The average is a little over 11,000 feet. These measurements depend upon the number and nature of exposures, determination of attitude, and the amount of section removed by erosion. Because of the latter one would take the highest figure obtained. In this case, however, that figure is questionable due to the other 2 factors. The most reliable figure is the little more than I 1,000 feet obtained on the Middle Fork of the Wishkah. j Lithologically the upper member is remarkably uniform Fig. 32.— Suggested correlation of sections measured along the West, Middle, and East Forks of the Wishkah River and the Wynoochee River. The boundary between the upper and lower members is taken as an arbitrary datum. It is located at the top of the highest significant sandstone bed in the J lower member. Where there is considerable cover relative j topography was used to help locate the boundary. It is not inecessarily a time line. WEST WEST FORK WISHKAH RIVER MIDDLE FORK WISHKAH RIVER SATSOP FORMATION EAST FORK WISHKAH RIVER WYNOOCHEE UNIT 7 UNIT 6 ID 3 0 0 UNIT S UNIT 4 UNIT 3 UNIT 2 UNIT I ASTORIA FORMATION 3 M IL E S I 1 /2 M ILES 3 M IL E S EAST RIVER DATUM. FIGU RE 3 2 G.A. FOWLER l*«8 131 132 throughout the Wishkah area. It is dominantly a tuffaceous ! mudstone. Very fine-grained sand and silt increases in j I i percentage upsection and from northwest to southeast. The base of the Montesano Formation rests upon an ero- jsion surface developed upon various parts of the Astoria j iFormation. The contact is marked by borings made by pele- j 1 i i |cypods and worms. Fragments of the Astoria are included in ithe basal few feet of the Montesano. In addition, an angu- l j jlar discordance of at least 30 degrees was measured between j bedding planes of the 2 formations. A second erosion surface truncates the uppermost strata iof the Montesano Formation. Upon this has been deposited I ithe poorly consolidated conglomerate, sandstone, and silt- I i istone of the Satsop Formation. | The section along the Middle Fork of the Wishkah River iis designated the type section for the Montesano Formation. [Northern Satsop Area i i I During this study, excellent exposures of the formation were examined along the Canyon River and the Middle and West Forks of the Satsop River. In general, the lithology [of the Montesano Formation displays less variability in the I [northern Satsop area than in the one previously described. 133 | j With one exception the formation averages about 7 50 feet I less in thickness in this area. The exception involves an i abnormal environmental situation which will be discussed ' later. j i ! Four sections of the Montesano Formation were measured ! i i I in the northern Satsop area (Fig. 13). Three are located along the northern perimeter of the Satsop Syncline. The j ! i fourth is south of the others and on the west flank of the ! i j syncline. ! i Canvon River The section measured along the Canyon River (Fig. 33) ! ! i |is continuously exposed; the top and bottom contact rela- ! I I tionships are clear cut; and there are no structural inter-j " | jruptions. The exposures along this section are typical of I j Ithe Montesano Formation along the northern part of the Sat-j I I Isop area and will be discussed in greatest detail. Discus sions of the other sections will contribute valuable sup plementary information. i A total thickness of about 1,900 feet was measured ! along the Canyon River. In this area the formation is composed predominantly of massive conglomeratic sandstone (Fig. 34). Local variations are sufficient to characteriae I Fig. 33.— Station locations, Canyon River. i STATION LOCATIONS CANYON RIVER TRAVERSE ASTORIA / FORMATION 2 9 / \ ! •A » C OF MONTCtANO FORMATION - i h IOOO 1 0 0 0 FCIT C l SAMPLE LOCATION RELIABLE ATTITUDE FAIRLY RELIABLE ATTITUDE ^ 4 UNRELIABLE ATTITUDE — f o r m a t i o n c o n t a c t (OASHCO VHCKC APPftOXIMATC) SYNCLINAL AXIS . APPROXIMATE LOCATION SATSOP FORMATION FISURE SS Fig. 34.— Columnar section of the Montesano Formation measured along the Canyon River. ® c X m LOWER t MIOCENE SERIES UPPER MIOCENE FORMATION ASTORIA Of hO Oi 2 > THICKNESS (M FEET) 200 100 200 200 2 0 0 i 200 200 60 200 SAMPLE NUMBER (C - ) ( s > r v > w wa> - < 4 a t w a m -J O H1 ( jJ CANYON RIVER SECTION 138 j ! individual portions of the column which will be examined | ! j jseparately. j The Montesano Formation is unconformable upon the As toria Formation as described earlier. There is no apparent angular discordance between these formations at this point (Fig. 33); however, in sections to the east and west, the j j jAstoria is absent and the Montesano rests upon the Lincoln j I Formation (Fig. 6). The unconformity is further illustrated j by small scale features at the contact. In typical fashion, 1 I I j i |the basal sand of the Montesano Formation was deposited on j an erosion surface marked by the borings of various marine organisms (Figs. 35 and 36). Also, fragments of the Astoria ! are included in the overlying sandstone. One well rounded, jdisc shaped clast was measured as 10 inches in diameter by i2 inches thick. It is completely riddled by borings, about I | i0.04 inch in diameter, probably made by worms. Portions of I several pelecypod borings also penetrate the fragment. The jextreme contrast between the environmental aspects of the | units on either side of the contact leaves little doubt that it is a distinct unconformity. Although foraminifera were not found in the basal strata of the Montesano, molluscan remains strongly indicate littoral to inner sublittoral j conditions. Foraminifera from the Astoria Formation on the Fig. 35.— Photograph of the contact between the Monte sano and Astoria Formations on the Canyon River. Arrow in dicates a mudstone clast in the sandstone. Knife is 6 [inches long. 140 Figure 35 Fig. 36.— Photograph of 2 hand specimens of the contact, shown in Figure 35. Notice the complete specimens of Peni- tella penita in their burrows (arrows). Figure 36 other hand are typical of upper to middle bathyal environ ments. Species given in the following list are diagnostic I I ! i of the Astoria on the Canyon River. i ! i Bolivina advena advena : i Bolivina marqinata pisciformis ; i Bulimina inflata alligata j j Bulimine11a curta Buccella vicksburgensis ' Epistominella carinata parva j Nonionella boueana costifera Stilostomella adolphina i Uviqerina hispida I Uvigerina peregrina hispidocostata | Uvigerina subperegrina ! This fauna is also characteristic of the Saucesian Stage j j j (Kleinpell, 1938) as recognized in the Northwest, j The lower 525 feet of the Montesano Formation along the jcanyon River is principally composed of rather well sorted, j fine- to very fine-grained sandstone (unit 1, Fig. 37). I Pebble- and granule-sized clasts comprise 10 to 15 per cent j i bf the interval. They are well rounded and mostly of al- ; ! tered basaltic composition. Considerably less than 1 per ! j cent of the clasts are disseminated through the sandstone. j I The remainder are in irregular beds up to 30 feet thick (Figs. 38 and 39). The thickest bed was observed to thin from 30 feet to 5 feet in about 1/2 mile parallel to the strike and slightly down dip. Gentle cross-bedding is com- i mon in both the conglomerate and sandstone. Mollusc shells, Fig. 37.— Photograph of a portion of the basal sand stone unit of the Montesano Formation in the Canyon River section. Exposure is in a cut on Simpson Logging Company's road above the Canyon River. Notice the large "cannon-ball sandstone concretion that has weathered from the formation (arrow). Also notice the layer of shell debris slightly below the center of the photograph. Hammer is 1 foot long. 145 Figure 37 Fig. 38.— Photograph of the lowest conglomerate bed, Canyon River. i Figure 38 Astoria Montesano Conglom Formation Formation erate 147 Fig. 39.— Photograph of the same bed as in Figure 38 exposed in a road cut above the Canyon River. Notice the icross-bedding. Hammer is 1 foot long. 149 I 150 | although common throughout the interval, are frequently | | concentrated in thin beds and with the conglomerate. When i in layers the shells are usually broken and abraded. The sandstone is easily friable except for local layers where j the silt and clay fraction reaches a percentage high enough ; ito be a binding agent or where calcium carbonate cement has ! ! i ! i formed concretions and concretionary beds. The latter j i features are scattered throughout the formation. Finely- j j divided carbonaceous debris and mica are abundant in places ! along bedding plane surfaces. Larger pieces of carbonized j i I ! wood, often abraded and with Teredo (?) borings are common, j 1 The end of a log at least 2 feet in diameter was observed j i protruding from an outcrop in the upper third of the inter val. "Worm" burrows are present locally. The sandstone is generally massive; however, bedding is defined by many of the features just discussed. When fresh the sandstone var- lies in color from light gray to bluish and greenish gray; | conglomerate tends to be dark gray, black, and greenish black; and the thin mudstone layers, dark gray to olive gray. With weathering, all the units become yellowish gray to various shades of orange and brown. ! Unit 1 grades upward into a silty sandstone and sandy mudstone unit (unit 2) extending for the next 150 feet (Fig. 151 40). Carbonaceous debris, mica, molluscs, foraminifera and small "worm" burrows are abundant. No conglomerate was ob- I served. The mudstone unit gradually gives way upsection to |sandstone (unit 3), similar to the basal unit, for 350 feet. i i | There is less conglomerate in this unit than in the latter, 5 except for the upper third, and silt is a little more abun- j j dant. Large sinuous "worm" burrows about 1 inch in diameter] i and up to 4 feet long are common in the lower portion. A j thin-bedded to laminated zone, approximately 50 feet thick, j is located near the middle of the interval. The laminations display gentle convolute structure. Carbonaceous debris j continues in abundance in this unit and throughout the re mainder of the formation. Within the next 325 feet of section the previous lith- | ology is replaced by pebbly and granulitic, medium-grained sandstone (unit 4). In general, the sorting is good and the rock is easily friable. Discontinuous, pebble conglom erate beds up to 3 feet thick comprise 5 to 10 per cent of I the interval. Carbonized wood, in pieces up to more than 1 foot across, is more abundant here than in any other part i jof the Montesano Formation along the Canyon River. Many jpieces contain filled borings possibly made by a species of Fig. 40.— Photograph of the sandy mudstone unit on the Canyon River at station C-13. 153 Figure 40 154 Teredo. This lithology grades into that of the underlying and overlying units. The final 550 feet is composed of massive, fine- to very fine-grained sandstone (unit 5). It is very friable i l and well sorted. Pebble conglomerate beds less than 2 feet j I thick comprise 1 to 2 per cent of the unit. These beds are j generally scoured into the underlying sandstone, have flat tops, and are often internally cross-bedded (Fig. 41). | Carbonaceous debris is relatively rare. A few possible j "worm" burrows were observed in the lower portion. With the exception of the latter and the previously mentioned Teredo (?) borings no evidence of marine organisms was I I I I (found in the last 900 feet of the formation. The section ends at the axis of the Satsop Syncline. A short distance downstream the Montesano Formation is ; t I (truncated by the Satsop Formation. Similar situations exist: i at the tops of all the other sections in this area. Satsop River, Upper West Fork To the west of the Canyon River very nearly the same sequence of lithologies was studied along the West Fork of the Satsop River (Fig. 42). As on the Canyon River, the section is very nearly continuously exposed. The Montesano Fig. 41.--Photograph of a conglomerate lense in the uppermost sandstone unit on the Canyon River. This bed is located approximately in the middle of station C-34. No tice that the lense is channeled into the underlying sand stone, the top is flat, and the lense is cross-bedded. {Hammer handle is 17 inches long. 156 Figure 41 Fig. 42.— Station locations, upper West Fork, Satsop River. 158 STATION LOCATIONS UPPER W EST FORK SATSOP RIVER TRAVERSE L IN C O L N FORMATION B A S E OF M O N T E S A N O FORMATION UWS I, 28 2 0 2 3 K>00 1000 2 0 0 0 FEET UWS I S A M P L E LOCATION y < $ R E L IA B L E A T T IT U D E <10 FAIRLY R E L I A B L E A T T I T U D E 24 .25 U N R E L I A B L E A T T IT U D E FO R M A T IO N C O N T A C T , A P P R O X IM A T E S A T S O P FORM ATION F I S U R E 4 2 Formation at that point was determined to be about 1,700 ! feet thick. This figure may be too high because of uncer- j tain relationships at the base. The basal contact of the formation is not as clearly exposed along the West Fork of the Satsop as on adjacent j i i sections. Existing exposures indicate a "contact zone" 70 j feet thick (Fig. 43). This zone consists of pebbly, medium-1 to coarse-grained sandstone with abundant mollusc shells | I and rounded clasts of the underlying formation up to at i I least 1 1/2 feet across. The latter are haphazardly dis- | i j tributed through the sandstone. One such clast may be 40 j feet across. Only the top and bottom of it were observed. It is badly fractured and apparently eroded at these 2 con tacts . Most likely this situation represents a coastal sea cliff at the beginning of the Montesano cycle of deposition. |A similar exposure, only on a smaller scale, was discussed i in an earlier portion of this report (Fig. 8). There is no evidence to suggest a post-Montesano fault of significant proportions. It is possible, however, that faulting caused the relief prior to the accumulation of sandstone in the Montesano Formation. The Montesano Formation rests upon tuffaceous mudstone of the Lincoln Formation along this section. Foraminifera Fig. 43.— Columnar section of the Montesano Formation measured along the upper West Fork, Satsop River. I 161 UPPER WEST FORK SA TSO P RIVER SECTION S E R IE S FORMATION UTHOLOOC UMTS S C A L E O 100 t o o FEET THICKNESS ( M FEET) SAMPLE NUMBER (U W *-I P L IO - P L E IS T . S A T S C P ■ s i t 1 . ■ . «• • . ^ * * j •' ----------------------AXIS Of STNCUNl = ■ = 2 5 - 2 4 T - T r i T . . 3 8 m r - p>.- M ?»*»• V % ’ • * % & * ¥ v i » + S •-4. i w - 2 8 - - - - 2 3 h - t - - - 22 • •* *» ^ - 9 0 r . * . . V . y W ^k>'- V ji.y p. r - * r i i i 219 ] 1 - - 1 9 : • . * • to ^ « * ■ f- "? s - - 1 8 - - 1 7 1 1 0 C E N E O rO • ■ i v . • ■ . ■ > * ; v . = - K - - C M 2 z < J - » — h i - ® - - - 1 6 1 5 C O V E R E D 3 9 c r UJ Q. 1- z o 2 CM E £ ^ E E ^ ? i E ^ § E ^ f t . : - - 14 - - 13 Ql -. <0 )-■*-- - - 12 L - - 10 m -s ’ ■ '■ ' ;‘> i ' : •..©»•• ••.&-.• . '■*'. + • F • i.'©Y.V ’ • =-34_-~ a > _ ro - - - ? 8 • ■ . i • • ••-»-.*•-. ••.•«"?•••• ^ r>. v- ij : --------- 6 K '-■•.••.r '.•'•■;••• '-•■ •ffT ••: • ■ : o.w.o»« r »• <?•' :• • *.T.. .4'. •<-<•' V**/•'■»«_, v-» <_ <D - - 4 s- O C O - 3 :- 30- - - - 2 C O N T A C T ZO N E ---------- 07* i i 01 i ; i * - - 1 OLIGO- CENE LINCOLN k M W M M • / / / / : 1 TOTAL THIOiNL^6 * 17 70 FEET ( FOR LEtENO SEE FISURE I t ) FIGURE 4 3 0 .A. FOWLER (OtS 162 contained in it are not particularly diagnostic of age. In i general, however, they appear older (perhaps Zemorrian) tharj I I foraminifera from the Astoria Formation discussed for the ! Canyon River section. There is no doubt that the latter I 'formation is stratigraphically younger than the tuffaceous | I j [ | jmudstone mentioned here. This lithology can be found in I * 1 the same stratigraphic position throughout Grays Harbor j i Basin. It, in fact, was observed below the Astoria Forma- j j i jtion on the Canyon River. The ubiquitous nature of the jlithology and extremely high ash content indicate possible 1 I jsynchroneity, perhaps reflecting the peak of Tertiary ex plosive vulcanism in the Northwest. The meager fauna given in the following list is more diagnostic of environment jthan precise age. Minimum water depth during deposition 1 I I !was probably on the order of 6,500 to 8,000 feet. Anomalina californiensis Cassidulina neocarinata (?) | Gyroidina soldanii soldanii i Gvroidina soldanii cristobalensis Uvioerina garzaensis nudorobusta Above the "contact zone" the sequence of lithologies is remarkably like that on the Canyon River (Fig. 43). Princi pal differences are in the thicknesses of the several units , involved. For instance, the basal unit on the West Fork of jthe Satsop is 700 feet thick compared with 525 on the Canyon 163 River. In addition, this portion of the column is more j ! I fossiliferous and contains a smaller percentage of conglom- I i l erate on the West Fork. The overlying sandy mudstone and silty sandstone unit is of very nearly the same thickness | and lithology on both streams. | Unit 3 is 410 feet thick on the West Fork of the Sat- j j sop. This is only 60 feet thicker than the same interval on the Canyon River, which is negligible considering the j error in measurement and that the unit boundaries are arbi- | i ! trarily placed. Of note is the lack of conglomerate in this unit on the West Fork. Mollusc remains and large "worm" borings are more abundant there. Also, the convo lute laminations described in the previous section are better developed. ] The final 460 feet of section on the West Fork of the jSatsop is identical to unit 4 on the Canyon River. Contrast between unit 4 and unit 3 is more noticeable on the West Fork. Conglomerate and carbonaceous debris is more abun dant. Teredo (?) and "worm" burrows constitute the only evidence found for a marine origin for the unit. The latter were observed only in the upper 40 feet. 164 Satsop Riverf upper Middle Fork A third section was measured along a portion of the Middle Pork of the Satsop River to the east of those just described. The Montesano Formation is less well exposed there but only 20 per cent is covered. Of further handicap, however, are the low dips through the middle part of the traverse (Pig. 44) making it difficult to measure attitudes i reliably. j i i Basal strata of the Montesano Formation on the upper j Middle Fork were deposited upon an erosion surface develop ed on the Lincoln Formation as previously described. The contact is marked by abundant borings of several marine organisms. The Lincoln is not quite as tuffaceous here as i on the West Fork of the Satsop. Foraminifera are more varied and abundant. The species in the following list ^generally characterize the fauna of the Lincoln Formation i i here . I Anomalina californiensis Bulimina inflata alliaata Cassidulina neocarinata Cassidulinoides erectus Cibicides pseudounaerianus Uvicrerina crarzaensis nudorobusta Age and water depth are about the same as for this fauna on the West Fork. Fig. 44.— Station locations, upper Middle Fork, Satsop River. 166 F IO U R E STATION LOCATIONS UPPER MIDDLE FORK SATSOP RIVER TRAVERSE L IN C O L N \ FORMATION B A S E O F M O N T E S A N O FO RM A TIO N tO O O F E E T 1000 1000 UMS I S A M P L E LOCATION ^ < 1 4 R E L IA B L E ATTITUDE FAIRLY R E L IA B L E AT TIT UD E U N R E L IA B L E A T TIT U D E FORM ATION CO NTA CT ( DASHED WH ERE APPROXIMATE) S Y N C L IN A L A X IS , A P P R O X IM A T E L O C A T IO N 167 Approximately 1,740 feet of massive, fine- to medium- I grained sandstone and conglomerate are present along this j i i stream (Fig. 45). Lithologic changes through the section, although relatively minor in magnitude, follow essentially j J I the same pattern as in the other 2 examined in this area. I I The lower 340 feet of section is composed predominantly t of massive, well sorted, easily friable, conglomeratic, , ! I fine- to medium-grained sandstone. Pebble conglomerate and; i sandy conglomerate in zones up to 40 feet thick comprise a j little more than 20 per cent of the interval. Several "worm" burrows constitute the only observed evidence of marine organisms. Carbonized plant debris is fairly com mon . Overlying the lower portion is an interval about 500 feet thick of fine-grained sandstone containing only 2 to 3 jper cent conglomerate. The latter is concentrated in thin, discontinuous beds near the top and bottom. Otherwise, textural characteristics are the same as in the preceding unit, Large mollusc shells are frequent in the lower half of the interval, particularly in thin beds near the base. "Worm" burrows are more abundant than in the underlying unit. Lenticular, calcareous sandstone concretions make up less than 5 per cent of the unit. This interval is perhaps Fig. 45.— Columnar section of the Montesano Formation measured along the upper Middle Fork, Satsop River. I m 0LI60- CENE SEMES UPPER MIOCENE * o< LINCOLN 2 A N D 3 O r . O 100 176 8 0 7 0 115 5 5 130 170 7 7 172 8 9 8 5 188 9 6 SAMPLE NUMBER (UNS-I r C “0 “0 m 73 o o I" m o 73 CO 5 CO o 73 73 < m 73 i f ) m o H O 1 6 9 equivalent to units 2 and 3 on the Canyon River and West | i Fork of the Satsop. ! j Fine- to medium-grained conglomeratic sandstone and conglomerate occupies the final 900 feet of the Montesano I Formation in this section. It contains a higher percentage ! of disseminated small pebble- and granule-sized clasts but otherwise is like the basal unit. Carbonized wood is more abundant and in larger sized pieces than in preceding units. No mollusc shells or "worm" burrows were observed. Satsop Riverf middle West Fork One of the most interesting sections studied is exposed i along the West Fork of the Satsop River to the south of its juncture with the Canyon River (Figs. 13 and 46). The top of this section is the same point as the top of the Canyon River section; the two being oriented directly opposite one j another. Measurement of the section began a short distance north of where the Mobray Fault zone crosses the West Fork of the Satsop. From there the line of section cuts diagon ally across the formation, making an angle of about 30 de grees with the average trend of the strike. It was not possible to trace the formation, without interruption, the length of the section. The West Fork of the Satsop has Fig. 46.— Station locations, middle West Fork, Satsop River. STATION LOCATIONS MIDDLE WEST FORK SATSOP RIVER TRAVERSE 1 ION M V S I SA M PL E LOCATION T IT U D E T IT U D E APPROXIM ATE B A SE O P LA M IN A TEO S H A L E UNIT developed unusually large and sinuous meanders through the i lower 2-mile stretch of the portion studied here and 3 miles i to the south. This is undoubtedly due to the shale in the formation at that point. The soft strata have also induced a great deal of slumping. Therefore, it was necessary to I j compile a columnar section by measuring segments that were j I clearly exposed and trying to correlate them by projection along the strike. These projections were made over a total ! I j distance of 4 miles. It must be understood that certain j hazards are involved in such a practice. Facies changes in the Montesano Formation can be very abrupt. Local faulting j in concealed areas could repeat portions of the section or I jcreate gaps. Small faults with little displacement are common; however, no substantial evidence for significant | faulting was observed. If the latter is present, the con sequence would be the determination of incorrect thickness. Possible instances of this will be brought out in the fol lowing discussion. Unfortunately, the section under study (Fig. 47) is only a partial one. Relationships at the basal contact and the lower 500 to 1,000 feet of the Montesano Formation were not available for direct observation. From data obtained iat scattered outcrops to the south along the West Fork and Fig. 47.— Columnar section of the Montesano Formation measured along the middle West Fork of the Satsop River. 175 MIDDLE WEST FORK, SATSOP RIVER SECTION U l o o o z < m o a J - m - - ^2gE2«j covimo ^ j su f fi st d o in 3 S 3 W - T t JL h8: S .?«2 7 - - 2 6 - 2 5 - 2 4 —23 -4 ? -20 - 1 9 - 1 8 -1 7 : 1S -1 4 -1 3 -12 -I I - 1 0 S S i & S i Infill? : v : : V : ' r ^ j •• • • ' • ' U J * L j + ; « rW , ■H'.-.VH ,'. ; ;.. • ••i-.-:--. zwZrhrra+cz- 0 0 O O m -CNJ- -OJ- CVJ )-CM- AXIS OP S A T SO P S V H C L IN I - 8 0 - 5 9 5 8 - 5 7 - 5 6 - 5 5 - 5 4 5 2 5 3 a5 1 o c vj V 3 T - - 4 0 - 3 9 3 7 — 3 6 3 8 - 4 7 4 6 - 4 5 - -4 4 - 4 3 - 4 2 -41 T H f O V tR L A P O r THK PA R T IA L S E C T IO N S SHOWN M I R I IS • M I D •O C C LV UPO N M A P P R O M O T IO N S . T N I S I S N I N T S OCCUR ALONS T H I S T R IK I OP T N I FO R M A T IO N . NO L IT H O L O S IC OR PA L IO N T O L O SIC M A R R IR H O RIZO N S W I R I N O T IO . I - I I P l i U R t 4 0 AND T N I D IS C U S S IO N S IN T N I T E X T .) ( FO R L I S I N S S I I P I S U R I IS > (BANC o r PONMATION NOT EXPOBEO> CSTIMATID THICKNESS EXPOSED • ESIO PCET F I6U R E 4 7 S. A . P O W L IR , I S M 176 | to the west along the ridge between the Satsop and Wynoocheej i I Valleys, the lithology of this basal unit is considered to be much like that described for the other sections in this area. The upper few feet of this interval were observed at i I 2 points at the beginning of the measured section. There j I the lithology is massive, rather well sorted, fine-grained ' I I I sandstone. Molluscs, carbonized wood, and small pebbles j I are common. : The uppermost 1,200 feet of the formation in this sec tion is lithologically similar in most respects to the top ! i j 1,200 feet on the Canyon River. There is a little less j conglomerate and the average grain size is smaller. ! i ! The most noteworthy part of this section occurs be tween the lower and upper sandstone units. For reasons brought out earlier, the thickness of this intermediate I junit is open to question but approximates 1,100 feet. A i ^maximum would be on the order of 1,700 feet. The reason for the difference being whether or not faulting has been significant in the upper part of the unit. The interval consists of thin-bedded to laminated siltstone, very fine-grained sandstone, and claystone. The lower 850 feet (Fig. 47) is the most representative and best exposed segment. Structural complications are at a 177 i minimum and there is little doubt of the thickness and se- j ) | quence of strata. The underlying sandstone unit appears to j ! grade up into the shale, although the transition is not well exposed. Fine- to very fine-grained sandstone beds up to several inches thick decrease in number and thickness up i section from the base of the unit. Large, thick, often fragmentary mollusc shells and carbonized wood fragments are associated with the sandstone beds. Convolute struc- j I ture is characteristic not only at the base but throughout the unit. It usually occurs in zones several feet thick bounded top and bottom by undisturbed laminae. Individual convolutions may measure more than 2 feet across, particu- I larly in the sandier beds (Fig. 48). Laminations in this lower segment are remarkably uniform (Fig. 49), although portions several inches to several feet thick display no J laminae. Major laminae average 0.4 inches in thickness but ! usually contain micro-laminations down to less than 0.04 inches (Fig. 50). A typical lamina consists of a dark and light layer. The dark layer is composed of olive gray, ! graded, very fine-grained sandstone, siltstone and clay- i stone. There may be more than one graded sequence of vary ing thickness within each dark layer. This is followed by I ja layer averaging less than 0.04 inches in thickness of Fig. 48.— Photograph of convolute structures in silty, very fine-grained sandstone at station MWS-38 on the West Fork of the Satsop River. Hammer handle is 17 inches long. Fig. 49.— Photograph of laminated mudstone at station MWS-14 on the West Fork of the Satsop River. Hammer handle is 17 inches long. 181 Figure 49 I Fig. 50.— Photograph of a hand specimen from the sec tion illustrated in Figure 49. Notice the alternating thick, dark colored layers and thin, light colored layers. 183 , I V V -4 q Figure 50 184 ! white, very light gray, or light yellowish gray fine silt | i and bentonitic clay. Pyrite is abundant in this layer. I Foraminifera are rare in the sand, common in the dark clay ! and most abundant in the light layers. Volcanic glass j I i shards are common to abundant throughout. The bentonitic ! i ! character of the light colored layers suggests that these I | are composed principally of finely divided ash. Diatoms ; are not particularly abundant anywhere but occur most fre quently in the coarser layers. Finely divided carbonaceous i ! debris is locally abundant. Fossil molluscs are small and j tend to be restricted to the more massive strata. ! i In the upper part of the previously described segment | ! and the overlying segments, laminations become thicker and ! I finally give way to thin-bedded strata (Figs. 51 and 52). There is also a gradual increase in the percentage of sand I I i and silt. Otherwise, the general characteristics of the lithology are much the same as previously described. The remainder of this unit is not well exposed and the suggestion of structural complication produces a degree of uncertainty in the sequence of strata. It is not clear whether several variable attitudes are the result of fault ing or slumping. Also, the sequence of strata in the vicin- jity of station MWS-38 (Fig. 46) when projected along the Fig. 51.— Photograph of thin-bedded to laminated stratd at station MWS-40 on the West Fork, Satsop River. Hammer handle is 17 inches long. Figure 51 Fig. 52.— Photograph of a portion of the section illus trated in Figure 51. Notice the difference in permeability as demonstrated by the wet (dark) and dry zones. White ob ject is 3 inches long. 188 Figure 52 189 j strike does not fit well into the sequence at MWS-52. This j | I could well be the effect of facies change. Data at hand j i i are not sufficient to solve the problem unequivocally. Since faulting cannot be proved and facies changes can be abrupt, the columnar section has been compiled as if there j were no faulting. For clarity, however, the individual I i ! [ segments are illustrated separately (Fig. 47). Of particular note is the presence in this unit of 3 j j zones of conglomerate and sandstone seemingly out of place | | i in the thick shale sequence. The most clearly exposed is 1 at station MWS-33 (Figs. 46 and 47). At that point a lense i of mixed types of coarse-grained sediment fills a channel i cut into the underlying shale (Fig. 53). The dominant sedi ment is a very poorly sorted pebbly and sandy mudstone ofter exhibiting convolutions. Rounded clasts of the underlying j I irock up to 2 feet across are common throughout the lense as j are fragments of thick pelecypod shells. Curved lenses of i i fairly well sorted, fine- to medium-grained sandstone and pebble conglomerate comprise 5 to 10 per cent of the sedi ment. The top of the lense is flat and overlain by thin- bedded to laminated shale identical to that below the lense (Fig. 54). It pinches out parallel to the strike between jthe 2 shale segments. Beyond the lense, the latter are Pig. 53.— Sketch of the filled channel in the vicinity station MWS-33, West Fork, Satsop River. 0 50 L i i . . i i I-------------------1 _____________1 ____________ I_____________I FEET VERT I C AL 2 X FIGURE 53 s. A . F O W L E R , l * « i 191 Fig. 54.— Photograph of part of the channel filling illustrated in Figure 53. Notice the lense-shaped bodies of sediment; poorly sorted nature of the deposits; and the capping of flat, thin-bedded to laminated mudstone. Hammer handle is 17 inches long. 193 Figure 54 i - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ■ ' 1 194 stratigraphically contiguous with no perceptible sign of j i the sandstone and conglomerate. j I I Two similar bodies of coarse-grained sediment occur ! higher in the section (Fig. 47). They are not filling dis- i tinct channels but the basal contacts are sharp. One (at MWS-52) is resting on thin-bedded mudstone and grades up j into massive, fine- to very fine-grained sandstone; the other (MWS-39) is on massive, fine- to very fine-grained ! j (sandstone and grades up into thin-bedded mudstone. The j latter can be traced for several hundred feet, thinning in at least 1 direction. Lithologically all 3 zones are much alike. j i i Summary i In the northern Satsop area the Montesano Formation i can be divided into a number of rather distinct lithologic units. These are best displayed on the Canyon River and the upper portion of the West Fork of the Satsop River where 5 can be recognized. They are in order from the base up: (1) fine-grained sandstone with conglomerate and common large mollusc shells; (2) sandy mudstone and silty sandstone with abundant small mollusc and foraminifera tests; (3) i f ine-grained sandstone with no conglomerate and common large 195 molluscs; (4) medium-grained sandstone with abundant con glomerate, carbonized wood and no molluscan fossils; and (5) fine-grained sandstone with a small percentage of con glomerate and carbonized wood and no molluscan remains. These units vary somewhat in thickness between the 2 sec tions but generally are similar (Fig. 55). To the east the sequence of strata is dissimilar to that to the west. Only 3 poorly defined units can be recog nized on the upper part of the Middle Fork of the Satsop ! River. They are: (1) a lower medium-grained sandstone with I abundant, thick conglomerate beds; (2) a middle fine-grainec sandstone with a small percentage of conglomerate and common 1 mollusc shells; and (3) an upper medium-grained sandstone with abundant conglomerate and carbonized wood. From the i Canyon River to the Middle Fork of the Satsop there is a marked increase in the percentage of conglomerate and in the SS/SH (Fig. 55). Total measured thicknesses of the 3 northernmost sec tions vary from 1,900 to 1,740 feet and average 1,800 feet. The differences are a result primarily of the sections being I terminated by reversals in attitude at various stratigraphic horizons near the center of the Satsop Syncline. Three units were recognized in the fourth section Fig. 55.— Suggested correlation of sections measured along the upper parts of the West and Middle Forks of the Satsop River and the Canyon River. Datum is a line through the parts of the sections representing the deepest water environments as based on studies of foraminifera and mol luscs . WEST EAST SATSOP 3 0 0 - . . i - u i Id • U. 0 - LINCOLN FIGURE 59 CANYON RIVER UPPER MIDDLE FORK SATSOP RIVER AXIS OF SA TSO P SYNCLINE UPPER WEST FORK SATSOP RIVER UHIT 5 FORMATION UNIT 4 UNIT 3 STR UCTURES — -ZONE OF CONVOLUTE D A TU M UNIT 2 w m m r y w # V < y a > U N IT LINCOLN FORMATION FORMATION#^® MILES ASTORIA FORMATION 4 M ILES B.A. FOWLER I M S 197 198 located along the middle portion of the West Fork of the J l I Satsop River. It is only a partial section, with 500 to j I i 1,000 feet at the base not observed. The lower and upper units are like unit 1 and units 3 through 5 respectively on the Canyon River. Between these 2 is an interval of lami- ! i nated to thin-bedded mudstone and very fine-grained sand- | stone displaying graded characteristics and convolute structure. A channel filled with pebbly and sandy mudstone ; j i and 2 other similar zones are unique to this section. This j interval is considered equivalent to unit 2 and the lower part of unit 3 on the Canyon River (Fig. 56). On the latter it is about 300 feet thick as compared to a minimum of 1,10C j feet on the middle portion of the West Fork of the Satsop— an increase by a factor of 4. On the 2 sections where the base was clearly exposed, i contact features were found like those described for the northern Wishkah area. In the present area the Montesano Formation was observed resting unconformably on both the Lincoln and Astoria Formations. Cloquallum Creek Area Only cursory examination of the Montesano Formation was possible in the several other areas where it crops out Pig. 56.— Suggested correlation of the Canyon River anc middle West Fork, Satsop River sections. Datum is a common point for the 2 sections, the top of each. SOUTH 300 -| NORTH MIDDLE W EST FORK SATSOP RIVER Z o K < 2 CL O I I . O z < V) LU H Z o 2 CANYON RIVER - * - „«<. * . .■ *— ^ • '.I m S T rrr. >T : •..f\ • " C ; ‘ • tVt V . * . #r • > < « 'a •. :: . ■ . • ifi* Jjl.**;.-: .* " ? •! a**&&& i a v i .n j r » » T -AXIS OF SATSOP SYNCLINE ?— ar-h:; LAMINATED BASIN SEDIMENTS / / / / - r .- * ; : u * w •* ; : * ■ U ' i \ ^ v - T r r r - . y ISISl .DATUM ASTORIA FORMATION 8ASE NOT EXPOSED FIGURE 56 e.A . FOWLER IO C 3 200 | 201 ;in Grays Harbor Basin. These will be discussed briefly in I order to obtain a broader view of the varying aspects of the formation. In the Cloquallum Creek area (Fig. 7) outcroppings of the Montesano are few in number and deeply weathered. The lower portion is composed chiefly of friable, medium- to coarse-grained sandstone with abundant disseminated granule- and pebble-sized clasts. Sandy mudstone and silty sandstone containing abundant carbonized wood fragments and a few mollusc shells locally form zones up to 10 feet thick. A conglomerate bed about 35 feet thick is present near the bottom of the formation. Highly rounded, cobble- to boulder-sized basalt clasts make up the major part of the bed. This is the coarsest-grained sediment yet observed in the Montesano Formation. The base of the bed is chan- i neled into the underlying sandstone. Upsection along Cloquallum Creek the lithology becomes ' medium- to fine-grained sandstone with progressively fewer pebbles and locally more silt and clay. Wood fragments remain abundant and molluscs increase in number, often occurring in thin beds. It is estimated that 1,5 00 to 2,000 feet of the Monte- i j sano have been preserved in the Cloquallum Creek area. This: 202 I is based upon very scattered field data and determined j I i [trigonometrically from a topographic map. I I : I i I Southern Satsop Area j j Based upon limited exposures on the south flank of the | Still Creek Syncline, it is possible to obtain a brief pic ture of the Montesano Formation in this area (Fig. 7). It is indeed unfortunate that more cannot be said, since this is the area first referred to by Weaver (1912). i Only about 1,000 feet of the Montesano is present in j ! the southern Satsop area. In general the sequence of stratq is like that in the lower part of the Canyon River and j neighboring sections. At the base, there are about 200 feet of sandy, pebble-conglomerate beds and well sorted, ! i ! friable, fine- to medium-grained sandstone. The conglomer- i ate beds are frequently more than 10 feet thick. This in- | j i terval is more resistant to erosion than strata above and j 1 i below and consequently forms a prominent break in topo- j I I graphy that can be traced for several miles. The basal interval grades up into approximately 150 feet of less well sorted, fine- to very fine-grained sand- jstone and silty sandstone. There is little or no conglom eratic material and mollusc remains are common. i 203 ! I J Next is an interval about 200 feet thick of massive to | thin-bedded sandy mudstone and siltstone. Local zones up to a few feet in thickness display the gentle convolute : j structure that is typical of unit 2 in sections to the north of this area. Finely divided carbonaceous debris and small ; molluscs are common. The remainder of the section is less well exposed than i 1 the lower part. Where observed it is composed of massive, friable, well sorted to silty, fine- to very fine-grained sandstone. Pebble-sized clasts, disseminated and in thin, discontinuous beds, make up less than 1 per cent of the j lithology. Carbonaceous debris and mollusc shells are I abundant. Southern Wishkah Area j i I Good but isolated outcrops of the Montesano Formation ! were observed along Newskah Creek on the south side of the j east end of Grays Harbor across from Aberdeen (Fig. 7). j i j These are the southern and southwesternmost exposures stud- j 1 I : I i iied in this investigation. j i ; The base of the Montesano was not observed in the j southern Wishkah area, but could be closely bracketed be tween adjacent outcrops. Numerous reliable and rather I 204 i I uniformly oriented attitudes were obtained throughout the Isection. Assuming no interruption by faults, the total thickness of the Montesano in the Newskah Syncline was ! J ^determined to be about 2,000 feet. Over 50 per cent of the I ’ formation is covered. The existing outcrops are composed |of massive, generally friable sandstone. Grain size varies from fine to very fine at the top to medium to coarse in the middle and averages fine to medium. Sorting is usually i good but least well developed near the top. Fossils are : i most abundant in the upper part but occur scattered through out. Granule- and pebble-sized clasts comprise less than 5 j per cent of the section and are concentrated in the middle I and lower portions. Carbonaceous debris is uniformly j i i i abundant. Calcareous sandstone concretions are common and i "worm" burrows are abundant near the top. No mudstone por tions were observed but could be present in the covered ; i i areas. i | A similar sequence of strata crops out in road and ;stream cuts east and north of Aberdeen in the north flank i of the Newskah Syncline. ! Summary and Conclusions i j Although discussions of the principal outcrop areas 205 | I were individually summar-ized, it would be well to tie them | itogether and point out regional trends. A thorough examina-] faion of the environmental implications of the lithologies ! land comparisons with underlying and overlying formations j j : will be brought out in later sections of this report. The Montesano Formation, wherever conditions at the ! faase could be observed, lies unconformably upon older | ; i jstrata. Several lines of evidence support this conclusion. ’ | j !In some areas there is an angular discordance of more than I ! i , |30 degrees between beds above and below the contact. The j Montesano not only rests upon both the Lincoln and Astoria ; I / [Formations but on various portions of at least the latter. | The environment of deposition of underlying strata is vari- i i | fable from point to point along the contact and may reflect water depths as great as 8,000 feet (Table 1). This is in distinct contrast to the littoral to inner sublittoral en- ! ! I vironment universally in evidence in the basal Montesano strata. The contact itself is usually an erosion surface i with relief up to more than 8 feet, marked by borings made i fay various marine organisms. Rounded clasts of the under- I lying rock, up to several feet across, are frequent in the faasal sandstone of the Montesano. | Throughout the area studied, almost without exception, I TABLE 1 j j COMPARISON OF APPROXIMATE WATER DEPTHS REPRESENTED BY FORAMINIFERAL j FAUNAS IN FORMATIONS BELOW THE MONTESANO FORMATION AT A NUMBER OF LOCALITIES ! Location Underlying Unit Depth (feet) West Fork, Wishkah River Astoria Formation 3,500-5,000 Middle Fork, Wishkah River Astoria Formation 650-1,000 Wynoochee River Astoria Formation 1,500 Upper West Fork, Satsop River Lincoln Formation 6,500-8,000 Canyon River Astoria Formation 3,500 Upper Middle Fork, Satsop River Lincoln Formation 6,500 Newskah Creek Astoria Formation 1,500-3,500 i ro o c r > | 207 | i j : jthe most coarsely-grained sediment was observed at the base |of the formation. This was followed by a general decrease I iin grain size for part, if not all, of the section. Faunal j I ,elements are characteristic of progressively deeper water upsection in parallel fashion with the change in grain size. i iThese factors coupled with relationships at the basal con- I tact indicate that deposition took place in a transgressive |sea for at least the lower part of the formation. Although highly irregular, there is a general trend i 'toward an increase in the average grain size of Montesano Isediments from west to east in Grays Harbor Basin. This is I ^paralleled by a decrease in the average depth of water in- I dicated by the fauna for the Montesano Formation as a whole. i : ^Therefore the sea transgressed from west to east. In all of the 4 western sections the transgressive character is present throughout the column. The Montesano can be divided into 2 members, a sandstone member with small amounts of mudstone and conglomerate and an overlying mud stone member. Minor facies changes are common and abrupt j in the sandstone member. Nevertheless, the general aspects I i can be traced with little difficulty through most of the | sections (Fig. 32). | In the eastern group of sections, the transgression was followed by regression. The sequence of lithologies in j ] ; jgeneral changes from sandstone and conglomerate at the base ; I through mudstone to sandstone and conglomerate at the top. The upper sandstone is more coarsely grained than the lower, contains a high percentage of carbonized wood, in pieces up j to several feet long, and has no unequivocally marine fos sils. Frequent local facies variations complicate this | i i ; I over-all pattern. As in the western area, there is little ! j ; problem in effecting a reasonable correlation between the j separate sections (Fig. 55). i ; | A distinctive facies of laminated shale with graded i | sandstone beds, convolute structures, and channel deposits ' occupies the middle portion of 1 section in the northern j ; ; Satsop area. Although 4 times the thickness, this unit is i ■ i I correlated with mudstone in a similar position in 2 other ! sections (Fig. 56). The large increase in thickness is ; I considered to be the result of repeated displacement of sediment by slumping and turbidity currents into a basin. Rapid facies changes make a positive correlation be- I tween the sections in the northern Wishkah area and those of the northern Satsop area difficult to achieve. In an attempt to do so, the relative frequencies of volcanic iglass shards were determined for the entire thickness of j 209 j | jboth the Middle Fork, Wishkah section and the Canyon River ; [section (Fig. 57). The distributional patterns display I ; Iremarkable similarity. To make this technique valid one i [ I must assume that the ash dispersal is relatively rapid and | | universal. Pyroclastic vulcanism has been a significant geologic process periodically throughout the Tertiary in the Northwest. Not only were large quantities of fine ash i ; widely distributed aerially but also the source areas of ' streams originating to the east were repeatedly covered with thick accumulations of coarser debris. During very j i active periods the streams carried large amounts of ash to j depositional sites. In between, little or none was depos ited. The shards observed in the sediment are fresh and j sharp, indicating that they were not eroded from very con- j : | solidated or old rock. The general sequence of lithologies in the lower mem ber on the Wishkah matches well that in the lower half of i the Montesano Formation on the Canyon River. The sandstone; , i I of the upper portion of the latter section, however, is in j ; i marked contrast to the upper mudstone member on the Wishkah] | j ; j The Canyon River section apparently reflects the regressive j cycle of the Montesano much earlier than does the Wishkah i I section. : Fig. 57.— Suggested correlation of the Canyon River ani jthe Middle Fork, Wishkah River sections based upon the rel- iative abundance of volcanic glass shards. Abundance is ex pressed as estimated percentage of the sand fraction. 211 WEST EAST MIDDLE FORK, WISHKAH RIVER PERCENT SHARDS 7 Z = ^ j - r m ± = - r r . ' j . ■■■ ■ ■ ♦ — — « « < 2 o: o ■V T v.v - . : " V ’ - \ > i- < V ) LU I- * .* :±±J:*• • * v . i f L * : .-V -T:* v -* r 7 5 —I_ 10 5 _ L_ 3 0 0 - 1 / CANYON RIVER 0 ......... / T T . r i l S i Hi! S l l i t -ASTORIA FORMATION FIGURE 57 6. A . F O W L E R 19 6 s ! 212 I j j Based on this correlation, at least 50 feet of the IMontesano Formation had been deposited in the northern Wishkah area before any deposition had taken place in the northern Satsop area. Also more than 5 00 feet more of the top of the formation is preserved in the former area than in the latter. The regional dip in the westernmost area studied is westerly and southwesterly beneath cover. This cover is principally the Satsop Formation which rests upon an ero sion surface on the Montesano and older formations. There fore the youngest portion of the Montesano has not been observed and presumably lies to the west. That part of the formation studied averages 2,500 feet thick in the northern Wishkah area and 1,800 feet in the northern Satsop area. This latter figure does not include the abnormally thick basinal section along the middle por tion of the West Fork of the Satsop River. There the thickness may exceed 3,000 feet. The section studied along the Middle Fork of the Wish kah River is designated the type section for the Montesano Formation. | 213 I Age and Correlation ; j i Introduction i j I ■ I Weaver (1912) originally referred the Montesano Forma- j tion to the Upper Miocene and stated that there were no i known marine deposits of Pliocene age in western Washington. He considered the molluscan fauna to be equivalent to those ; Of the Empire Formation of Oregon and the San Pablo Forma tion of California. Arnold and Hannibal (1913) also made a correlation to the Empire and San Pablo but considered the age to be Middle Miocene. In later investigations Weaver (1937, 1943, and 1944) gradually revised his estimate of [ the age of the Montesano Formation, finally stating that it I was predominantly Early and Middle Pliocene but ranged down ! ! i into the latest Miocene. These early determinations were based almost entirely upon molluscan remains. Weaver, how- ; i i ever, extended the formation down into the Miocene primarily on paleobotanical evidence. La Motte (1936) identified 14 I species from basal strata of the Montesano Formation near | Aberdeen. The flora was considered to have an aspect typi- j i cal of the Mascall Flora of eastern Oregon and to be of Late Miocene age. This is the only previous record of iplant fossils from the formation. A small, fragmental flora was collected during the present study from a bed labout 350 feet above the base along the Canyon River (Fig. | 33). D. I. Axelrod (personal communication, University of : i California, Los Angeles, 1963) stated the following regard ing this material. The collection is much too small to suggest closely an age, but I believe that it probably is Miocene rather than Pliocene to judge from the composition of the Plio cene Troutdale flora near Portland, Oregon. ! Such data, although not alone conclusive, help to substan tiate determinations from other lines of evidence. No vertebrate remains were encountered in the Monte- ; sano. The formation is not known to interfinger with ter restrial deposits containing extensive vertebrate and plant i ‘ assemblages as do many of the marine formations in Califor- ; nia. There is, therefore, no possibility of a tie-in with j mammalian provincial ages. It is the viewpoint of some workers that vertebrates offer one of the better opportuni- j ties for correlation with the European "standard sections" I Ifor the classical Lyellian epochs of the Tertiary (Durham, iet al.. 1954; Evernden, £t al., 1964). In marine sections, j j : i planktonic foraminifera, when present, have been demonstra- j ted to be as reliable, or more so, for interregional corre lations (Bandy, 1964a). Their application in the present jstudy will be pointed out later in this report. ! i ! j Two classifications of the marine section are in gen- I i ieral usage in studies of the Pacific Coast Cenozoic; a sub- ' | t Idivision based upon "megafossils" and a foraminiferal sub division. Durham (1954) has pointed out that the standard imegafossil "stages" have evolved in a haphazard and undis ciplined manner. They are based upon faunas within isolated i ! formations and sequences of formations taken to be charac teristic of different parts of the Tertiary; however, most iare not defined and do not have formally designated type sections. The foraminiferal subdivisions, on the other ; hand, are based upon carefully disciplined studies of essen tially continuous sections and are well defined. The latter! i I are generally considered more reliable because of the pre- j vious statement and the fact that larger populations of foraminifera better demonstrate the variability within I i species. I Megafossils were collected whenever observed during j ] I ithe course of field work; however, an intensive treatment j of them is beyond the scope of the present report. They | i will, for the present at least, be used primarily to help j establish paleoenvironmental trends. j Foraminiferal Biostratiaraphy I The foraminifera of the Montesano Formation have not ibeen discussed previously in the literature. Such an over sight is indeed unfortunate. The fauna is large, varied, and well preserved in at least portions of the formation. Knowledge of foraminifera from this part of the column in the Pacific Northwest is all but lacking and very necessary for an adequate understanding of local and regional strati- igraphic problems. More than 100 species of foraminifera were observed in |the Montesano Formation during the course of examining over 200 samples. Eighty-four of the species have been identi fied (Tables 2, 3, 4 and 5). The others were present in too few numbers to enable reliable determinations. None of the Montesano species differ significantly enough from described forms to warrant designation of them as new. Original references to faunal names used are given at the end of this report. It is possible that new species or subspecies are present but this cannot be affirmed until a critical examination is made of type specimens and until more Montesano material is analyzed statistically. Fifty- i ;five species comprise more than 1 per cent of the fauna in TABLE 2 - RELATIVE ABUNDANCE O F FORAMINIFERA AND OTHER MICROFOSSILS, MONTES> MIDDLE FORK. WISHKAH RIVER a i m s (VK-) 1 2 3 * 3 6 7 8 9 10 1 1 I t 1 3 1* 13 1 6 17 18 19 2 0 2 1 22 23 2 * 2 5 26 27 2 8 29 30 31 32 33 3* 3 5 36 H A T Q«1C M e m o L o a x a n n u b o l l q t w * s o i x o i t s a amililTH O L O T T K A T A a t a t s o n m p * c u o n i u a t o e z a n n u Q tm o o n o B i a r o i a n m o r o u OLOBOBOTALXA CBASSAPOBtfZS QL080BQTALIA SCI T P U SCITCLA OKBOLIBA US1YUSA 63 12 50 25 1 0 0 50 57 * 3 *3 33 33 17 26 33 19 57 52 35 67 7 . 5 100 5 7 6? 7 20 2 2 31 25 ? X —roc spscm AHM 8A CU LX TSS S t. AMQLOOnZSA AB00L08A a h o q l o s s o t a m w a s a i BOLZOTA ADVSU 9T1X A TB LLA (SH A LL POIH) •OLIYZHA C A L Z PO B SIC A B0UT1I& Z B C O S S A T A ■ ol x o t a m u k iz s a ta h o b i c a ju BOLITOU O B L X Q O A b o l i t o a u n n i BOLTYHA YAW BUBI WOCHIA PBIOIOA B T T T iT H T B A A tm IS ■ Q UOTA B C BA CPO TA TA ■oLnm m iA s i i y i o s ■ Q L z m n u A c a l z p o s b z c a B O U O T SU A c o m ■ o l z o t s u a b l b o a b t i s s d u PiMTMTJi CALIPOMISXS1S CALIPOBIIXMSIS CAJSXOBUA C A L Z PO B H X SM SIS TXCKSSI3 C lM T M T J i io b p i a b a C A S S Z B O L X B A D BU CATA CAS8XS0LXIA L A S Y Z Q A T A M M T m t . m H0KL0DSI8 CASSZinLXBA BOKLOSSSIS (K X SLSD PO H H ) PiMWTT.tii OTUTA C A SIX SD LZ B A S O B O S A B O S A Q O A D S A T A CASSHWLIBOIOn C O B S O T A CAS8ZD0LZS0IE88 SIHPLKX X 20 19 2 X 1 0 X 5 1 9 * 2 17 6 3 x 29 19 1 7 57 X * X X 7 X 7 33 12 7 2 * 17 3 33 X X X 1 6 11 11 X X 33 3 t X X 6 21 3 * 20 2 X 22 2 X X 11 CZBXCZBBS LOSATOS czbiczebs K C K A j n u t i CXCLAMIIHA CAVCSLLATA a o r r A i . T X A b a o o i w n t w m w i i A A D V IIA P m U B W Otg lC P L A M SPZSVOOTSLU CAOTATA PACIFICA ■ P m O O T O X A KXIOQA BPXJTOfdKKLLA CAHHUTA SHITB BPIBTOHXXXLU S0&PK8UY1AHA CAUPOSMICA rxaSUO TA LOCXSA OTSQOTA SABOIBATA rZ O T O T A OBLOBOA r a m h a s p . QLAPPfg.nU LASYIOATA w flm n r.i O T A o v d la OX101OTA S P . ■ A B Z A U A Z A IUJB01 ■APLOPBSAOROItttS C0LO TB1SH SS LAODU E L 0B O A T A u a n u l a s y is LAOTA PBLDCIQA u a n u s a m i A T A u a n u SOLCATA u a n u s p p. Lcxoaiomw b a a k u tr i HZUAIOTA PQSCA bobzob A P ra is mncnxu s c a p b a b a s i s p i b a t a BOBIOKBLU LD M A TA m i o m u hzoobica polzjbza ajLUM xani PXBOO BOLLOU3S8 qOZWJDBLOCQLZBA AXBIBtAHA BXLLATULA tjUllKJUBLO CPLTIIA SIH1BUU O f f . botosbxbsxxa (?) o A irx m s is S P B A B B O Z D Z B A YABZABZU8 UYIOBUXA BOOT9I KXJTSI o v i a n m u b o o tsz k o d b lo x h sis u Y zan iB A m s a t U A e is p z b o c o s ta ta O Y I O B B I B A 8 B 0 0 H D 0 S 8 8 I 8 DVianiBA mPMBOBTBA * 17 15 12 c X * 7 3 X 8 12 X 1 11 X X 5 21 18 * 7 7* 1 9 6 1 X 1 19 1 1 1 1 1 5 38 X 5 11 7 P 37 7 X X X X X I X 2 X 3 2 I X X X 7 10 7 k k X 8 3 I t 11 7 1 2 17 7 3 6 9 X X X X X X 5 6 * I 3 X 30 20 32 1? 6 17 X X X X X * X 3 2 2 X X 1 X 2 X X 2 7 8 10 1 * 18 36 3 8 8 2 A 15 39 13 X X 2 X 1 X X X X X 1 X X X X X X 2 5 X 6 6 10 18 I 10 9 6 10 9 * * 1 0 2 20 X X X X X X X X X X X 1 X X X X X X X X X X X X X X X X X X X X X X 2 X X X X X X X X X X I X X 2 ' X t X X X X X X X X X X X 1 X X X ? X X t 3 3 1 X X X X 6 X 99 9 9 99 99 9* 9 9 1 00 PUBXTOBIC SPBCXS8 PBBODfT B I O T I C 0PSCZBS PP CBtT PO SCUAHSOOS PO lA PIISIPtlAL H U IBSB B A O IO L A B Z A B BUHBSB D IA T O H ItffB ta STATOLITH HQHB8B obtbaooob m a n n 'XX XX 9 9 99 9 9 9 9 7 8 X X ?A 59 12 7 1 0 X 9 X X 7 t X X 10 0 9 9 99 X 2 2 9 38 XX* 6 10 1 X 9 9 20 1A 11 X X 9 9 9 8 1 0 0 1 00 9 9 1 0 0 100 1 5 1 X 1 8 X 1 6 6 0 3 0 1 7 6 9 6 5 0 2 1 3 6 1* 3 956 532 35 2 0 • 1 X * 2 8? 1 5 * 8 15 6 8 33 139 129 33 3 3 21 X 3 2 9 2 5 0 2 6 * 8 8 2 6 9 3 1 3 2 80 20* 123 9 1 3 3 81 x x x x 3 x x « 3 3 * x x : _X____________________ X ____________________ X - LSSS T B A B O H S POCDT O B LIBS T H A B O K S PSB 08AH. T O I W i i C - O OKTAHZBATIOH P - F iiflflff, m o o n B —BI.TABIS t • p o c b tp u l z s n r rz p z o A T io B • - VHX L O W 000R SPBCZBS A B U H D A B C S IS O IV E H AS PSB C SH T O P T O TA L PLAHKTOnC O S BIOTIC POfOUTXOS IVE A B U N D A N C E O F F O R A M IN I F E R A AND O T H E R M I C R O F O S S I L S , M O N T E S A N O F O R M A T I O N . 2 1 ^ E FORK. W ISHK A H RIVER 1 0 0 7 100 6 7 1 5 1 00 100 100 100 1 0 0 5 3 1 9 3 3 100 20 10 10 1 7 2 1 12 17 2 1 2 9 1 9 1 7 5 7 2 6 1 7 1 6 1 1 2 6 11 10 1 * 39 22 11 10 I S 1 9 11 6 1 10 10 10 20 6 1 7 1 5 1 * 11 12 21 11 t l 8 12 5 11 1 6 1 7 1 5 5 8 1 6 9 9 9 9 9 9 10 0 9 9 99 9 9 20 9 8 100 100 99 10 0 100 1 0 0 1 0 0 9 9 9 9 9 9 9 9 9 9 100 X 7 6 3 9 X 2 2 9 1 8 60 30,1 76 9 6 5 0 2 1 3 6 1 6 } 9 5 6 5 3 2 2 0 92 10 3 2 9 2 5 0 2 6 6 8 8 2 6 9 5 1 5 2 8 0 2 0 6 1 25 9 1 mm O T A R , o n 218 TABLE 3 - R E L A T I V E ABUNDANCE O F FORAMINIFERA AND OTHER MICROFOSSILS, M ON TE SAN O FORMATION s m n i n u m u — - 9 H 1* 15 16 I* 27 29 30 9 10 11 13 15 17 5 13 15 19 11 23 *5 *7 19 31 plaittohic specie 0L0B10E1IHA RVLL01EBS BULL0IDC3 oLMiontu ncm Dm u OLoeianiu quiHquELOSA OLOBIOEBIKA VJXJtA OLOBOBOTALIA SCITU1A SCITVLA OBV U U UV1VSKU 3* 1 * hh 8 6 A h 1 0 0 ICC ICO ICC mitt mein AMKBACJLITES SP. iwotoanm amoulosa BOLITIHA A m u STBLATELLA (SHALL POM) BOLXVIHA OCCUUATA BOLTrXBA HAfeOIRATA HOBICANA BOLITIHA OBL1QUA bolitiha i m m BOLITIHA TAOOHAKI i o c c h u — *»» BUCCELLA FBXOIDA BUL1R1HA APP1BIS tuunnui cubta BULlHimiA tUOAVTlSSIKA CAlSItKLLA CALIPOHHIEH3I3 CAL1POM1DS1S CiASIEKLU CALXPOIHICH3I5 TJCSX3I3 CAEIDELLA SIB FLA HA CASJIDULIHA OKI. 1 CAT A CA5SIH7LIRA LAITIOATA assnuuHA nodciakhsis assnvuHA boikloexsis (keeled pobb) CAS9IDUUHA RITOTA CASSIMJLXHA StJBOLOBOSA ;UAWUTA CASS10UUB0IDK3 COBfUTA CASSIWtlSCIDKS SIMPLEX CIBICIDH3 PLITCBUI CIBICIDCS NCXAIKAI tSNTALXU BAOOI ELPBIDTW OSS1CUUAB ELPHIMW ■OCH71ASUK tPISTOHimU BBADTAHA EPISTOHIKLLA CA1IHATA PACIFICA EPISTOHIUUA CA1IMATA 3HITHI EPIBTORITOAA EXIOUA FISSUBIHA LUCIDA PISSUBIBA RABOIHATA PISSUBDU OBLOMOA FISSUBIHA BP. OLOBOSULIIUHA OVULA OLOBOBULIHXHA PACIFICA lARZAtfAlA ILL!BOX ■APL4PE1A CMDirSS COLIIRBIXNSE UOOA PBALDCIDA laooa simaniATA UOOA SPP. KA10IHUUBA SP. HILlAimiHA PU3CA NOIIOKKLLA XIOCSXICA B0RI0HXLLA SCAP1U BASISPIHATA FULUHIA ULISBUXI1 QUIBQUKLOCULIHA AKKDIAKA BELLA TULA K W T I U BP. toTonxnuA (t> oabycxensis siohonobpiixiu sp. UVianXHA BOOTS I BOOTS 1 UTIOKBIKA ROOTS I ROWLOOSU UTIEBOIHA PtSSOIIBA HXSPIDOCOSTATA utioebiha stomootxsjs utioebiha stmpnsoaiSA TIMJULIHEUA PtBTUSA 5 18 25 2 56 37 16 A c n i X 6 5 10 11 5 1 $ 11 30 51 2 3 10 3 21 11 6 10 7 * 2 6 6 19 8 12 X X A X 15 IB X X A X X 1 X X X X X X 11 t 6 2 7 7 7 100 100 ioo 100 100 99 100 100 100 100 100 100 100 100 99 100 100 100 100 IOC ICC »9 96 100 9* 90 93 93 93 h 17 li 63 2 1 2 1 7 9 16 31 3 1 X * * 93 2h i t 10 X AM 315 119 17 95 305 32 75 X 675 313 56 n 26 hi 36 19 10 70 22 2> 50 56 X 9 3 X X 19 5 3 13 *5 105 36 12 13 109 19 3 5 5 3 8 2 1 h 3 3 2 5 h? 27 3 17 177 83 50 93 hi 05 35 98 10 13 12 17 35 117 105 h 15 X 1 X 1 9 h h 5 2 X X X 1 3 1 2 1 2 p t t c n r r p l a k k t o h ic species p n c n r r behttuc specie PSBCnrr ABEHACEOUS PEBCtMT POHCELAXEOtlS POBAflXXIPIJUL MtJMBBt BADI0LAB1AM XVnil DIATOM ItlUl STATOLITH HUMBER OSTBACOCK HUfBEB TABLE 4 -RELATIVE ABUNDANCE OF FORAMINIFERA AND OTHER MICROFOSSILS, MONTESANO FORMATION, MIDDLE WEST FORK, SATSOP RIVER SAMPLE NUMBER — (NWS-) I 2 3 5 7 9 11 13 it 16 18 21 23 25 2? 28 29 30 31 32 33 3t 35 37 38 to t2 tt t6 t7 ta 51 5t 56 57 PUNPTONIC SPECIES GLOBIGEBINA BULLOIDES BULLOIDES 9 13 15 33 33 26 *7 39 28 36 25 19 18 17 89 11 17 50 100 t2 6 GLOBIGEBINA OLUTINATA 12 13 2 7 11 15 9 t 6 16 t 9 20 It 50 GLOBIGEBINA PACHTDEHMA 2 9 1 X 9 9 6 t 6 A A 13 10 60 13 100 t 13 50 GLOBIGEBINA ^UINQUELOBA 72 63 80 59 ti 37 3t t9 t3 tl 5t 50 57 73 20 6l 11 100 89 50 33 50 5t 81 50 100 GLOBIGEBINA UVULA 5 3 2 X 6 9 t t 6 10 t 12 10 k 100 7 GLOBOBOTALIA SCITULA SCITULA 2 1 BENTHIC SPECIES ANGULOGERINA ANGULOSA X X X X BOLIVINA sehinum X X B0LIV1NA VAUGHAKI It 13 8 9 11 17 13 17 15 It 16 22 13 22 t3 38 11 1 39 3 33 t5 *3 50 18 7 22 30 3* tt 33 BUCCELLA BLAKCOENSIS X X X X 2 2 X BI'CCEIIA FRIGID* X X X X 2 1 X X X 2 2 2 X It X 1 7 5 X X X Bin.IRINA AFFINIS X X BtLININELLA CALIP0BK1CA X X Bl’ LIRINELLA CUBTA 21 1 X 5 3 7 it 6 5 X X X 2 3 3 2 2 20 3 5 5 10 EULIHINELLA ELEGANTISSIRA 29 52 *3 *5 tt 18 15 17 it 28 35 35 to 6 18 13 X 20 10 31 23 t 6 19 10 6 5 13 39 75 50 CASSIDELU CAL1F0BNIENSIS TICENSIS 5 2 X X 2 1 t 3 5 t A 2 5 7 2 5 7 16 5 X CASSIDELLA SUBPLANA t X 2 X X 2 2 X 1 X 23 X 2 CASSIDULINA RINIPTA t 3 5 2 t 3 5 3 5 2 1 2 2 X t 2 X 3 9 2 X CIBICIDES FLETCHERI 2 X X X 1 X X X CIB1CIDES LOBATUS X ELPHIDIUP 033ICULARE X 5 7 7 7 X X X X X 7 1 X ELPHIDIUN RUGUL05UP! 8 3 12 9 6 X 1 2 X 3 5 1 3 X 71 9t 1 85 9 10 7 X 5 X 3 7 EPISTORINELU B BA DIANA 3 3 3 5 2 6 EPISTORINELU CAB1KATA PACIFICA 1 X X 2 3 5 t X X X 16 5 3 2 X 29 3 10 3 5 EPISTORINELU EXIGUA 9 17 11 12 It tl 36 tt ts tl 30 19 20 33 t3 18 It 2 31 11 33 19 16 8 16 tl 39 25 18 9 FISSUBIHA LUCIDA X X X X X X X . X X X X X GLANDULIHA SP. X GL0B0BLXIR1NA OVUU X X X CL0B0BULIH1NA PACIFICA X X X X X 2 X X 3 l 2 3 CUTTULINA SP. X HANZAWAIA ILLINGI 2 X X X LAGENA ALCOCKI LAGENA AKPHOBA UCENA LAEVIS IAOENA PERCLUCIDA X RILIANRINA PUSCA 2 2 2 X X X 2 2 2 3 X 1 X X X X 1 NODOSARIA SP. X NOKIOKELLA LUNATA X KONIONELU RIOCENICA t 1 7 3 2 X X X X t 7 2 7 7 1 2 X 5 1 6 X 6 7 t 17 NONIONELIA SCAPHA BASISPINATA X X X X X 2 X X 3 X 1 X X 2 1 1 6 6 50 ROTORRINELU (?) SP. X UV1GERINA HOOTSI HOOTSI X X X X X X VIRGULIHELU PBHTUSA X 2 X 5 PERCENT PLANKTONIC SPECIES 21 29 19 13 17 7 12 12 It 7 6 13 10 2 t2 13 5 2 X 2 15 2 3 8 1 10 5 2 3 PERCENT BENTHIC SPECIES 79 71 81 07 83 93 88 66 86 93 9t 81 90 98 58 87 95 78 99 98 85 98 97 ICO 92 99 90 95 98 97 100 100 PERCENT ABEHACEOUS 2 2 2 X X X 2 2 2 3 X 1 X X X X 1 PERCENT PORCELANEOUS FORANINIFERAL NUMBER 0 28 36 22 63 77 ltt 235 208 19t 83 79 30 13t 95 2 30 63 227 115 168 29 99 25 t3 6 125 t2 58 38 13 68 t 1 0 RADIOURIAN NUHBER 0 t 2 X 1 2 2 1 t 2 X 5 1 2 X X 1 1 6 2 0 6 1 0 5 X 1 X X 1 0 C 0 0 DIATOR NUHBEB 0 2t 8 6 13 20 l?t 131 125 112 87 21 to 16 to t? 12 t 18 9 7 13 123 2 5 tt 2t 29 23 9t t 2 C 0 0 STATOLITH NURBEB X X X X X X 2 X 1 X X X 1 X 1 1 2 l X 1 1 t 1 OSTBACODE NUMBER X X X X X - LESS THAN OKB PERCENT OB tjbm THAN ONE FEB GEAR, DBI HEIGHT SPECIES ABUNDANCE IS GIVEN AS FEBCENT OP TOTAL PUNXT0N1C OB BENTHIC POPULATION <9 A. Fowler, I9t5 219 220 TABLE 5 - RELATIVE A B U N D A N C E OF FOR AMI NIFE RA AND OTHER M I C R O FOSS ILS, MONTESANO FORMATION, CANYON RIVER SAMPLE NUMBER -- (C-) 1 2 3 * * 5 6 ? 8 9 10 11 12 13 lU 15 16 17 18 19 PLAMtTWK OLOBIOEBINA BULLOIDES 1 100 IOC QLOBIOKRINA QUINQUELOBA 99 BENTHIC SPECIES BOLIVINA VAUOHANI 19 5 3 BUCCELLA BLANCOENSIS 2 9 X BUCCELU PHIOIDA 6 X 5 X BULIMINELLA CURTA 10 BULIMINELLA ELEOANTISSIHA 23 100 81 22 59 19 75 50 CASSIDELLA CALIPORNIENSIS TICENSIS i * 1U 1 18 CASSIDELLA SUBPIANA X CASSIDULINA MINUTA 2 CIBICIDES PLETCHERI 1 ELPHIDIUM RUOULOSUM 39 X EPISTOMINELLA BRADYANA X 10 X 11 OLOBOBULININA OVUU 2 3 1 11 OLOBOBULIMIHA PACIFICA X 11 1 * HANZAWAIA ILLINGI 5 HAPLOPKRAOMOIDES COLUHBIENSE X 19 2 X 50 LAOENA SPP. X HILIAMNINA PUSCA 11 2 I * X NONIONELLA LUNATA I* NONIONELLA KIOCENICA X 2 10 15 3 25 NONIONELLA SCAPHA BASISPINATA 6 UVIOERINA HOOTSI HOOTSI X PERCENT PLANKTONIC SPECIES 7 X 1 PERCENT BENTHIC SPECIES 93 100 100 99 99 100 100 PERCENT ARENACEOUS 11 X 21 6 1 50 PERCENT PORCELANEOUS FORAMINIFERAL NUMBER 238 h 81 38 51 322 1 X RADIOLAEIAN NUMBER X X X i * X X 2 8 3 DIATOM NUMBER 127 9 9 Zk 2 30 STATOLITH NUMBER X 9 X X 1 OSTRACODE NUMBER X X X - LESS THAN ONE PERCENT OR LESS THAN ONE PER ORAN, DRY WEIGHT SPECIES ABUNDANCE IS OIVEN AS PERCENT OP TOTAL PLANKTONIC OR BENTHIC POPULATION S. A. Fo**ltr,iivs at least 1 sample. The remainder are generally too rare in Itheir occurrence to be considered stratigraphically signi- ! ; jficant. Many of these, however, are important in establish ing paleobathymetry. The largest and most varied foraminiferal faunas were jobserved in the upper member in the northern Wishkah area. .Smaller and less well preserved, but nevertheless distinc tive, assemblages are present in the silty portions of the Slower member. An additional well preserved, though sorae- jwhat restricted, fauna occurs in the laminated shale unit , ,on the West Fork of the Satsop River and the silty part of | the Canyon River section. Similar faunas were studied from isolated samples from the lower part of the West Fork of ! j ; j the Satsop and from the Wynoochee River north of the meas- ! ; i ured section. Both planktonic and benthic types of foraminifera are present in the Montesano Formation. Early investigators of' ! i the Tertiary strata tended to rely on benthic forms for j I .dating and correlation. In more recent years many excellent studies have demonstrated the great usefulness of planktonic} i | foraminifera (see Bandy, 1964a). The 2 groups will be j itreated independently in the present evaluation of the i 'Montesano Fauna. I 222 j I Planktonic Foraminifera i l s Time designations and correlations with units from ! j i jother geographic areas ideally should be based upon plank- ! 1 : i 1 tonic faunas. Classic examples of this point involve the graptolites of the Ordovician and the ammonoids of Late Paleozoic and Mesozoic time. In the Late Mesozoic and Cenozoic, planktonic foraminifera took over the role of Ithese ideal time markers. Since the early 1950's a steadily I : ] ; increasing number of investigators have been focusing their j attentions upon the stratigraphic and ecologic significance bf this group in various parts of the world. Their efforts i are providing us with more reliable means of tying in with | the standard European stages (Bandy, 1964a). Almost exclu- j j ;sively, established stratigraphic zonations have been set j : i up in tropical and sub-tropical regions where faunas are most abundant and most diversified. The marked latitudinal | zonation of planktonic foraminifera is well known (Bandy, j I I 1960a) and poses a serious obstacle to the extrapolation of | : ! planktonic stratigraphic zones poleward from the tropics. j Published works to date on foraminifera from Tertiary j ■ j Strata in the Pacific Northwest have treated planktonic i ! jforms only superficially. Reference to them has been large ly as Globigerina bulloides or Globigerina sp. This trend iprobably developed as a result of rare occurrence, often .inadequate preservation, and inherent difficulties in the jidentification of planktonic foraminifera. The present i study and earlier investigations by the writer have revealed i ja rather large diversity of planktonic species in the Ter- jtiary formations of Oregon and Washington. I ; i Planktonic foraminifera, unfortunately, are present in I ‘ very low numbers in the Montesano Formation with one notable ^exception. Along the Middle Fork of the Wishkah River they j average considerably less than 1 per cent of the total fauna | j : i and reach a maximum of 6 per cent (Table 2). The laminated shale on the West Fork of the Satsop contains up to 30 per cent planktonics and an average of about 15 per cent (Table j j 4). This large variation in abundance is largely the re- > suit of environmental conditions which will be discussed in i | a later chapter of this report. ! i i At least S species of planktonic foraminifera are pre- i I i sent in the Montesano Formation. They are given in the j ifollowing list. I ] ; Globigerina bulloides bulloides i Globigerina glutinata i Globigerina pachyderma I Globigerina guinaueloba Globigerina uvula [ 224 | I ! ! . ! i Globorotalia crassaformis Globorotalia scitula J ; Orbulina universa i : ^11 of these species except Globorotalia crassaformis have ! • j i been reported living in waters of the northeast Pacific (Bradshaw, 1959; Smith, 1963 and 1964). : Globigerina bulloides bulloides. as used in this re port, possibly includes several sometimes separated sub species. These include G. bulloides quadrilatera and G. i I bulloides bulliformis. However, criteria seem insufficient ! | to make a subdivision. ! i ! Only Globigerina pachyderma and Globorotalia crassa- j ; i formis are at present considered to have chronologic signi- ! ficance in Late Cenozoic correlations of this investigation.! ;A single specimen of the latter was found in the upper mem- i : j ber of the Montesano on the Middle Fork of the Wishkah i River. It is listed by Bandy (1964a) as an index to the j Middle Pliocene and as possibly restricted to that portion I of the column. Parker (1962) on the other hand reported j j I jthe species from Recent sediments and plankton tows in the i i ! I ^southeast Pacific. Her illustrations portray the species ' ! | |in typical form. Bandy's conclusions are apparently based | primarily on its stratigraphic distribution in Italy and in the Ventura Basin of California. On a world-wide basis the i i 225 : I | jrange may be not nearly so restricted. In any event, the |presence of a single specimen leads to a strong suspicion of contamination and no reliance can be placed on it as a i j ichronologic marker for the Montesano Formation. Globicrerina pachvderma exhibits progressive change with latitude in the preferred direction of coiling (Ericson, 1959); Bandy, 1960c). The evaluation of coiling direction [in planktonic foraminifera has been demonstrated to be a i valuable stratigraphic tool (Bolli, 1950; Bandy, 1964a). Bandy (1960b) observed stratigraphically restricted zones | in the Late Cenozoic of Southern California in which G. pachyderma coiled either right or left. He was able to define the Pliocene-Pleistocene boundary on that basis and j ; i to correlate between wells. Ingle (1962) successfully usedi I ; | [coiling direction trends in the same species to correlate i Upper Miocene and Pliocene strata in the area near Capis- | I trano, California. A summation of the stratigraphic range 1 and coiling characteristics of G. pachvderma in the southerp California region is given by Bandy (1964a). The presence of G. pachyderma in the Montesano Forma- i ! i : i ition suggests that a tie-in might be made with the southern | j California sections. Observed coiling direction of this I i jspecies exhibited a random pattern with a slight tendency I 226 i 1 f i jtoward a higher percentage of right-handed forms. However, i 1 . ! jso few specimens were available for examination that the ; results are unreliable. In most samples fewer than 10 in- I Idividuals and never more than 5 0 were observed. Also, , ; I truly typical forms of this species are even more rare in j ; the formation. ! Usefulness of planktonic foraminifera in the Montesano | : i ;is limited because of the lack of diversity and the small ! : ! isize of most individuals. The average diameter of G. pachy- j I I | ;derma is less than 0.006 inches. Be (1959) has pointed out ' the difficulty involved in attempting to distinguish be- i I tween several similar species when dealing with specimens j this small. Furthermore, planktonic foraminifera in the formation occur in short, isolated stratigraphic intervals I irather than more or less throughout continuous sections as i in southern California. To make coiling changes meaning ful, it is necessary to have a framework of continuous events for a considerable length of time. I Bandy and Kolpack (1963) indicate a decrease in the javerage diameter of Globicrerina concinna from 0.018 inches |in the Relizian Stage of the California Miocene to 0.006 I : inches in the lower Mohnian in the Tecolote Tunnel section |of southern California. There is a similar trend from ! 227 ! ' 0.012 inches for G. concinna in the Astoria Formation of Grays Harbor Basin to 0.004 inches for Globiaerina quinque- loba in the Montesano Formation. The latter species differs! only slightly from the former. Specimens of G. quinqueloba from the Montesano were compared with those identified as jG. concinna by Bandy from the lower Mohnian of the above isection. The degree of similarity is so great that the (writer sees no reason for a separation. Possibly G. quin- I ^ i j i gueloba should be considered a subspecies of G. concinna. ; The size ranges of foraminifera is dependent upon so I I many factors that it is difficult to have much confidence j j | in such similarities as the one just described. It does, ' I | ■however, lend some support to other evidence. i IBenthic Foraminifera I i i I j With the absence from the fauna of diagnostic plank- ! ! i tonic elements one must rely on benthic foraminifera. This j I ! is not a particularly bad alternative. Correlation of j ! i ! I lassemblages from the same environment and the same zoogeo- i I Igraphic province is entirely reasonable. A comparison of i jstudies by Bandy (1953) and Enbysk (1960) reveals for in- | stance that very nearly the same foraminifera species are !present in modern assemblages from off the coasts of j 228 Washington, Oregon and California, although not necessarily ,in the same abundance or with exactly the same depth limits. I I All 3 states lie within the Californian (or Oregonian) Pro- I ; vince; Grays Harbor Basin is near the northern end. Several very careful zonations have been made of Ter tiary foraminifera in California. Kleinpell's (1938) |treatment of Miocene forms and Natland's (195 3) for the i i Pliocene are most pertinent to this investigation of the iMontesano Formation. These zonations are the closest that can be used for evaluation of the Montesano foraminifera. ; The writer's experience has been that many species are com-i mon to both the California and Pacific Northwest Tertiary sections. Not only are the same species present but they ; i occur in much the same stratigraphic order. This is not to : 1 ; I say that these homotaxial series are absolute chronologic equivalents. Certainly some migration of forms is involved^ However, it is very likely that such migrations would have j ! 4 i taken a negligible amount of geologic time, considering the j j i short distance involved and the lack of physical barriers. ! iThe California species not found in the Northwest are for ithe most part large, robust, more exotic, probably more i jwarm tolerant forms. All foraminifera here reported from i i ithe Montesano are present in Miocene and younger strata of California. j i ! | Benthic foraminiferal biostratigraphy of the Montesano Formation will be based upon the Middle Fork of the Wishkah j River section (Fig. 58) since it is to be the type section and since the most complete collections are from it. The J other 3 sections in the northern Wishkah area contain the jsame faunal assemblages. Supporting evidence will be drawn from sections in other areas. Faunal differences between ' i ithe several areas are largely environmental in nature. It |must also be emphasized that differences from the bottom to the top of the section (Fig. 58) are largely controlled by j I i i ! environmental factors. | Few of the foraminifera in the Montesano Formation are j 'particularly useful for assigning narrow limits on its age. i ; i ;Most are too rare; too long ranging (many to the present); or of equivocal identity or significance. Species consid ered most significant along with their known ranges are j summarized (Fig. 59) from data taken from Kleinpell (1938), iMartin (1952), Pierce (1955), Smith (1960), Ingle (1962), | land Bandy and Kolpack (196 3). It is evident that most of J S i Ithe species listed have rather narrow ranges m the Califor-j- j | inia Miocene section. They are most characteristic of the j j i jUpper Miocene, Mohnian and Delmontian Stages of Kleinpell. Fig. 58.— Stratigraphic distribution of benthic foram inifera, Montesano Formation, Wishkah River. 231 111 IB ~I Fig. 59.— Known ranges through California Miocene and Pliocene Stages of diagnostic benthic foraminifera from the iMontesano Formation. T] Q c 33 m tn ( 0 ft o1 « r f t 10 3 H a a* s » H Sp 3 ® a -< - j a 9 a SAUCESIAN HELIZIAN LUISIAN MOHNIAN DELMONTIAN REPETTIAN VENTURIAN WHEELERIAN 233 Several species are particularly noteworthy. For instance, j | Rotorbinella (?) aarvevensis. which ranges through the top 675 feet of the Middle Fork, Wishkah section, suddenly be- i i 1 comes very abundant 300 feet from the top; reaches values of 30, 32 and 25 per cent in successive samples; then drops off just as suddenly 100 feet from the top (Fig. 58). There appears no logical environmental cause of the distributional trend. Its occurrence is similar in the 3 other sections ! studied in the northern Wishkah area. This distinctive I : species is considered a guide fossil for the uppermost Mio- j cene in California, the Rotorbinella (?) crarveyensis (Rotal-j i ia aarvevensis) Zone of the upper Delmontian (Wissler, I 1943). ; : ! j j Of lesser abundance and with principal occurrence some-j j Iwhat stratigraphically lower than the previous species is ! Bolivina obliqua. It reaches an abundance of only 10 per I ! cent but has its maximum occurrence through as equally nar- i row a stratigraphic interval as Rotorbinella ( ? ) garveyen- j ; i ;sis . In consistent association with it are Bolivina rank in i| |and Bolivina marainata monicana. Bolivina obliqua is the j i i i j guide species for the Bolivina obliqua Zone of the lower : ! belmontian (Kleinpell, 1938). None of the other California j jzone so-called index fossils is present in the Montesano Formation. j Hanzawaia illinai is almost universally illustrated by iauthors as being restricted, or nearly so, to the Mohnian. It does not occur frequently in the Montesano but does reach 38 per cent near the middle of the formation (Fig. 58). Cassidella californiensis ticensis is one of several rather distinct subspecies of a species that is widely dis- , I : tributed in the Miocene section of California. It has per haps the most restricted range in the California Tertiary iof all the Montesano foraminifera. There are not enough data, however, to confirm this. The few reports of this subspecies have been only from lower Mohnian strata. i A smaller but equally distinct species, Cassidella | I I ! | ^subolana. is given in most reports as Delmontian in age. * i | The fact that this species occurs consistently with the previous one through the formation suggest that one or both | of the ranges are in need of adjustment. ! Uviaerina hootsi hootsi and U. hootsi modeloensis are j : j usually considered characteristic of the Mohnian and DelmonH i tian. Their occurrence, however, is thought to be environ- j i ! Smentally controlled (Ingle, 1962). They have been reported ! ; | |as rare in Pliocene and possibly younger strata. In the j jMontesano Formation, the 2 subspecies are present in low ! 236 i I but significant numbers just below the Bolivina obliqua Zone. i : No new biostratigraphic zones are recommended on the : i basis of data resulting from this study. Those previously reported appear to hold true for at least the upper part of the formation. Therefore, the upper 300 feet of the Monte sano on the Middle Fork of the Wishkah River are referred , to the Rotorbinella (?) garvevensis Zone of the upper Del montian Stage. The next stratigraphically lower 300 feet is referrable to the Bolivina obliqua Zone of the lower Delmontian. The remaining portion of the upper member con- j tains a Cassidella californiensis californiensis. Episto- minella carinata pacifica. Uviaerina hootsi hootsi. Cassi- i j i dulina modeloensis. Buliminella curta assemblage but nothing of zonal calibre. Considering the early and late Delmontian age suggested^ for the upper member and the presence of Hanzawaia illingi : I in the lower, an undifferentiated Mohnian age is assigned j | ito the latter. The foraminiferal assemblage in the lower ' I | member is typical of sublittoral environments to be dis- j icussed later. None of the species in the assemblage is i considered worthy of zonal rank. j It is desirable wherever possible to equate strata to jthe original type sections for geologic time divisions. s (Those for the Tertiary are located in various parts of j ; I (Europe. The use of benthic species for this purpose is j : i , I dangerous, particularly for late Tertiary sections, because j of the marked zoogeographic groupings that gradually devel- i i oped through the Tertiary. Planktonic foraminifera, how- ; ;ever, offer excellent possibilities. Unfortunately, as was | i i ipointed out earlier, planktonics in the Montesano Formation; are non-diagnostic. Bandy (in Bandy and Kolpack, 1963), on the basis of preliminary planktonic studies in California, j referred the Mohnian to the middle and upper Tortonian and j : i the lower Sarmatian Stages of Europe and the Delmontian to | the upper Sarmatian and at least the lower Pontian. This j j is consistent with correlations based upon vertebrate re mains (Durham, gt al., 1954), and it is generally verified j by recent correlations based upon absolute chronology (Evernden, gt .al. , 1964). jFaunal Comparisons with Older and Younger Units i Astoria Formation j The Astoria Formation is the youngest unit beneath the j |Montesano Formation. Foraminifera from the Astoria in the (Grays Harbor Basin have been studied by Rau (1948, 1951 and | |1958). These reports placed the highest then-known Astoria I foraminifera in the questionably highest portion of Klein- ' i pell's Saucesian Stage of the Lower Miocene. This writer has made a brief examination of foramini- j fera from strata immediately underlying the Montesano Format l ; ition in a number of places throughout the area studied. Results were given in the chapter on physical stratigraphy. In addition, an attempt was made to compile a composite ! i ^section for the Astoria Formation. Structural complications! and poor exposures in the immediate vicinity of the Monte- j I i sano outcrop area necessitated going elsewhere to obtain the section. For this an area was chosen immediately east j 5 i and slightly north of Raymond (Fig. 60). Because of the i ^ i cursory nature of the examination, no detail can be demon strated and there is definite doubt of the determined thick-j ness. However, the general sequence and approximate spacing! of stations is correct. ; i i Selected samples from the composite Astoria section ! jwere examined for foraminifera. Only the most abundant and j i | ^significant species were analyzed (Table 6). On the basis j lof the fauna present, this investigator confirms a Saucesian |age for the bulk of the Astoria Formation studied. There Fig. 60.— Sample location map and tentative composite jcolumnar section for the Astoria Formation in Grays Harbor basin. F IG U R E U P P E R • S A N D S T O N E ( S o o L o g o n d t F o r F i g a r o * 3 , 6 o n d 1 9 ) 8 A F O W L E R 240 241 TABLE 6 - RELATIVE ABUNDANCE OF DOMINANT AND DIAGNOSTIC FORAMINIFERA, COMPOSITE ASTORIA FORMATION, GRAYS HARBOR BASIN SAMPLE NUMBER -- (A-) 1 2 3 4 5 6 7 8 9 PLANKTONIC SPECIES GLOBIOERINA BULLOIDES 90 83 88 20 100 GLOBIOERINA CONCINNA 15 7 11 74 78 GLOBIGERINA CONCLOMERATA 85 GLOBIOERINA UVULA 10 10 1 GLOBOQUADRINA THIPAHTITA TRIPARTITA X GLOBOHOTALIA SCITULA PRAESCITULA 1 X X BENTHIC SPECIES AMMONIA BECCARII 2 ANOULOGERINA OCCIDENTALIS 10 1 14 14 2 2 BOLIVINA ADVENA ADVENA 22 551 70 BOLIVINA ADVENA ASTORIENSIS 22 1 BOLIVINA ADVENA STRIATELLA 6 8 10 10 BOLIVINA FASTIOIA 2 BOLIVINA MARGINATA PISCIFORMIS 1 6 14 15 BOLIVINA SCALPRATA MIOCENICA 1 BUCCELLA VICKSBURGENSIS 1 2 3 2 BULIMINA INFLATA ALLIGATA 3 BULIMINA MONTEREYANA 4 BULIMINELLA CALIFORNICA 2 8 3 8 5 BULIMINELLA CURTA 3 2 l BULIMINELLA ELEGANTISSIMA 8 l 5 CASSIDELLA BRAMLETTEI 1 11 CASSIDULINA MINUTA 2 1 1 7 CASSIDULINA NEOCARINATA 6 16 4 8 7 CASSIDULINA SUBGLOBOSA 2 l CASSIDULINA SYMMETRICA 2 2 CASSIDULINOIDES ERECTUS 8 CIBICIDES PSEUDOUNGERIANUS 3 2 3 3 3 3 EPISTOMINELLA CARINATA PARVA 42 17 23 11 15 11 EPISTOMINELLA SUBPERUVIANA 34 EPONIDES UMBONATUS 4 1 GLOBOBULIMINA OVULA 8 2 0 0 17 10 6 HANZAWAIA MENLOENSIS 1 1 2 NONIONELLA BOUEANA COSTIFERA 3 16 NONIONELLA INCISA 1 1 1 7 NONIONELLA LUNATA 4 7 NONIONELLA MIOCENICA 9 2 8 NONIONELLA SCAPHA BASISPINATA 2 PLANULINA BAGGI 2 PLANULINA CUSHMANI 3 PLECTOFRONDICULARIA MIOCENICA 1 ROBULUS AMERICANUS 2 ROBULUS INORNATUS 4 ROBULUS MIOCENICUS 3 ROBULUS SIMPLEX 6 SIPHOGENERINA TRANSVERSA 2 STILOSTOMELLA ADOLPHINA 1 STILOSTOMELLA ADVENA 1 UVIOEHINA PEREGRINA HISPIDOCOSTATA 2 UVIOERINELLA CALIFORNICA ORNATA 4 UVIOERINELLA OBESA IMPOLITA 36 13 VALVULINERIA ARAUCANA 2 1 2 2 2 X - LESS THAN ONE PERCENT SPECIES ABUNDANCE IS GIVEN AS PERCENT OF TOTAL PLANKTONIC OR BENTHIC POPULATION <S. A, F * o w / « r ( 242 | jis, however, a definite Relizian or younger 1 1 aspect" to 1 jforaminifera from strata high in the section. This is dem onstrated by the presence of Bagqina californica and the jgreat abundance of Bolivina advena striatella. Since no foraminifera were observed in the highest portions of the I iformation, it is quite probable that the upper, part of the jAstoria is definitely Relizian. I j There is no evidence for faunas of Luisian age in Grays Harbor Basin. This conclusion is in line with the marked I unconformity below the Montesano Formation which requires a significant time lapse. This break may have regional sig- j inificance. Kleinpell (1938) noted that the faunal change between the Luisian and Mohnian Stages was the most pro nounced in the California Miocene. Wheeler and Mallory i (1963) consider that a pre-Upper Miocene stratigraphic break is evident throughout most of the northwestern United States. This is not supported by the continuous Middle Miocene deposits of many California sections. ; j Two distinctive planktonic foraminifera in the Astoria j i ■ i Formation of the Grays Harbor area afford the opportunity j of a possible tie-in with faunas from other parts of the ; jworld. To the best of the writer's knowledge these species j 'have not been reported previously from the West Coast j j~ 243 i 1 Tertiary. Three typical specimens of Globoquadrina tri- i jpartita tripartita were observed in sample A-5 (Table 6). j ; ! ) jThis species is known to range from the uppermost Eocene j |(upper Priabonian) to the lowermost Aquitanian (Eames, et al.. 1962; Bandy, 1964a). Therefore, its presence in the I lower Astoria Formation suggests that part of the formation ; i iis no higher than lower Aquitanian. I ! I Globorotalia scitula praescitula occurs with Globoquadr rina tripartita tripartita in sample A-5 and also at A-4, | ; |A-6, and immediately below the base of the Montesano Forma- | ition on the Middle Fork of the Wishkah River. This species | i ] was described by Blow (1959) from Lower Miocene strata in Venezuela. It was illustrated ranging from the lower Aqui- I tanian to the lower Burdigalian. In Australia, Jenkins i ; j (1960) noted the sudden appearance of this species at about ; j the same stratigraphic position as the initial appearance 5 I up section of Globigerinoides triloba triloba. The first I i I i . ! ioccurrence of the latter species is considered by Bandy ! i s (1964a) as marking the beginning of the Aquitanian. The : I i I last appearance of Globorotalia scitula praescitula in Aus tralia is shortly after the first occurrence of GloborotaliE. I i Imenardii praemenardii or at approximately middle Burdigal- jian (see Bandy, 1964a). A form similar to Globorotalia 244 j i scitula praescitula was illustrated by Drooger and Batjes ,(1959) from the Miocene of the Netherlands. Associations i • were not clearly established; however, they appear rather | jclose to those just discussed. j ' The joint occurrence of Globoquadrina tripartita tri- ! partita and Globorotalia scitula praescitula rather narrow- ! ; i jly limits the stratigraphic position of the basal Astoria i ' j : [Formation in Grays Harbor Basin as lowermost Aquitanian. The benthic assemblage associated with Globorotalia scitula ! : jpraescitula just below the Montesano Formation on the Middle iFork of the Wishkah was previously reported in this paper j i I t I : as being typical of the Relizian "aspect" of higher parts I of the Astoria Formation. Since the known upper limit of j |this planktonic foraminifer is about middle Burdigalian, i ; j the upper part of the Astoria in the Grays Harbor area may be middle Burdigalian or higher. Bandy (in Bandy and Kol- ; : I pack, 1963) estimated that the base of the Relizian corre lates with about the middle of the Burdigalian. Thus the | ; i I ; findings of the 2 studies are consistent. I | ; In contrast to Globorotalia scitula praescitula in the | I j Astoria Formation, typical specimens of Globorotalia scitulsj i I i jscitula are present in the Montesano Formation. | i j In addition to the difference in planktonics, there is | |a marked change in benthic foraminifera between the Astoria jand Montesano Formations. Few species are common to both. i I j i i ' Only a few of the more striking differences will be pointed i I • ! jout here. It is not the objective of this study to under take an intensive analysis of the Astoria foraminifera, j (although this is needed. | The Baaaina-Siphogenerina-Valvulineria assemblages so jtypical of Lower and Middle Miocene deposits of California land sparingly represented in the Astoria Formation are com pletely absent from the Montesano assemblages. Also, there is an almost 100 per cent change in the bolivinid fauna. j ! j The following list contains species observed in the 2 forma-1 tions during this study. j Astoria Formation: Bolivina advena advena Bolivina advena astoriensis Bolivina advena striatella Bolivina brevior Bolivina fastiaia Bolivina marainata pisciformis Bolivina scalprata miocenica I Montesano Formation: Bolivina advena striatella j (small form) | Bolivina decussata I Bolivina marainata monicana I Bolivina obliqua j Bolivina rankini Bolivina seminuda | Bolivina vauahani Nonionella boueana costifera. a very distinctive sublittoral 246 i I I jspecies that ranges through the Astoria Formation, is re- ! i jplaced by N. scauha basispinata in the Montesano Formation. ; Another switch in dominant shallow water species took place : ' ■ i j [between Buccella vicksburgensis of the Astoria and B. frigi- ^ da of the Montesano. Uvigerinella. abundantly represented ; jin the Astoria, is not present in the Montesano. The list i could go on. ; i ; S i ] Quinault Formation j ; i I : i Weaver (1916) at one time considered the Quinault | ; I Formation equivalent to the Montesano Formation and, in ! i fact, made no distinction between them. At that time he j i gave the age of the Quinault as Late Miocene, in contrast J ! to Arnold's (19 06) original designation of Pliocene. i i | I Weaver (1944) later revised his estimate of the age to j Middle to Late Pliocene. The only published account of foraminifera from the Quinault is in a short article by Cushman, et al.. (1949). They considered a small fauna obtained from 2 samples to i have strongest affinities for the Lower Pliocene of Cali- j ifornia. The Quinault Formation crops out along the coast 30 jrailes northwest of the nearest exposures of the Montesano Formation studied by this investigator. The intervening area is largely covered by the Satsop Formation and exist- i I ing outcrops are hopelessly weathered. It is therefore I jimpossible, with the means at hand, to trace out the physi- | cal stratigraphic relationship between the Quinault and pontesano Formations. The writer briefly examined the Quinault, measured an ; I i . j japproximate columnar section, and collected a representative 'suite of samples through it (Fig. 61). Exposures are iso lated and it is difficult to be confident of the exact 1 i I ' stratigraphy. Although a complete treatment of this forma- \ bion is not within the scope of this paper, the data at hand i afford an ample comparison with the Montesano. ; I i A well preserved, abundant and varied microfauna was I i obtained. The distribution of the more abundant and dis- j tinctive species is discussed (Table 7). In contrast to I I the situation between the Montesano and Astoria Formations, j 7 I ; I I I there are many species in common to the Montesano and Quin- j i I iault. Many of the faunal differences present are probably j environmentally controlled. In general, the Quinault for- | ! jaminifera are in a better state of preservation and have a | more "modern" aspect. j i Particularly noteworthy are several Quinault planktonic I I I Fig. 61.— Sample location map and tentative columnar jsection for the Quinault Formation. 249 F IG U R E s M O N T E S A N O A B E R D E E N GRAY S— >HA RBOR v > Z OC O Id Hm z 1 0 20 S T A T U T E M IL E S C A P E E L IZ A B E T H T A H O L A H 012 4 3 5 0 0 COVERED CRESCENT FORM ATION ( S . 1 9 ) 01 P O IN T G R E N V IL L E S T A T U T E M IL E S SI * . * . row LtM 250 TABLE 7 - RELATIVE ABUNDANCE OF DOMINANT AND DIAG NOSTIC FORAMINIFERA, QUINAULT FORMATION SAMPLE NUMBER -- (Q-) 1 2 3 1 * 5 6 7 8 9 10 11 12 PLANKTONIC SPECIES OLOBIOERINA BULLOIDES 13 10 30 58 1 * 692 32 35 GLOBIGERINA OLUTINATA 11 16 8 li 3 l l * X OLOBIOERINA PACHYDERMA 3 2 X 3 27 8 37 OLOBIOERINA QUINQUELOBA 58 57 1 * 118 5 2 4 7 38 15 OLOBIOERINA UVULA 10 i4 17 26 6 X 8 9 OLOBOROTALIA CRASSAFORMIS X OLOBOROTALIA PUNCTICULATA X 2 X 1 OLOBOROTALIA SCITULA SCITULA X 1 X X X 1 ORBULINA UNIVERSA X BENTHIC SPECIES BOLIVINA VAUGHANI X X 16 10 19 7 25 56 3 X BUCCELLA FRIOIDA 5 X 3 9 X X 1 3 2 BUCCELLA TENERRIMA 5 17 X 2 BULIMINELLA CURTA X X X X 7 5 BULIMINELLA ELEOANTISSIMA X 5 13 19 2 19 9 X CASSIDULINA LIMBATA 23 1 * 9 32 3 9 5 6 8 CASSIDULINA MINUTA 10 X 20 13 16 3 9 19 1 16 15 CIBICIDES FLETCHERI « * 21 * 928 25 17 3 CIBICIDES LOBATUS 2 X 3 X CIBICIDES MCKANNAI SUPPRESSUS 3 2 DISCORBIS COLUMBIENSIS 2 7 X 3 X ELPHIDIELLA HANNAI X X X 1 5 ELPHIDIUM FRIGIDUM X X 5 7 8 9 2 X ELPHIDIUM INCERTUM 3 X 1 7 X X 9 EPISTOMINELLA CABINATA PACIFICA X 3 3 X 13 3 17 EPISTOMINELLA EXIGUA 3 39 20 GLOBOBULIMINA PACIFICA X 8 57 1 1 X X NONIONELLA MIOCENICA STELLA X 3 X 9 X 1 6 NONIONELLA SCAPHA BASISPINATA X 8 5 1 X 1 PLECTOFRONDICULARIA CALIFORNICA X PULLENIA SALISBURYI X SUOGRUNDA ECKISI i * UVIGERINA HOOTSI HOOTSI 2 1 * 1 UVIGERINA JUNCEA X UVIGERINA PEREORINA HISPIDOCOSTATA X X UVIGERINA SUBPEREGRINA X X 7 X 1 3 X - LESS THAN ONE PERCENT SPECIES ABUNDANCE IS GIVEN AS PERCENT OF TOTAL PLANKTONIC OR BENTHIC POPULATION < 5 . A. Foutltr t f965 251 | I species. Numerous, typical specimens of Globorotalia punc- jticulata were observed throughout the formation. This spe- I cies has not been reported living off the Washington Coast; ; 1 jhowever, it is a member of modern faunas in more southern portions of the Pacific (Bandy, 1964a). Despite its pres- jence among the living, G. puncticulata is the dominant plankter in Lower Pliocene strata in many parts of the world 'and is considered a guide species for the Lower Pliocene '(Bandy, 1964a) . j : I Globiaerina pachvderma occurs in much more typical form ’ in the Quinault Formation, particularly in the upper part, I i than it did in the Montesano Formation. In the lower por- | tion of the Quinault it is represented by rare, small speci-j ; i mens that tend to coil right-handed. G. pachvderma com- ; | prises up to almost 40 per cent of the planktonic fauna in j the upper portion of the Quinault. There it consistently displays a left coiling preference, averaging more than 80 per cent sinistral specimens. In southern California a j | i dominance of sinistral forms is found only in the latest Miocene, Middle Pliocene, and Pleistocene (Bandy, 1964a). The remainder of the time, in that area, the species coiled jdominantly to the right as it does today. Parker (1962) jreported 87 per cent right coiling (dextral) at 40° N ! 2 5 2 ! i 1 I I jLatitude in the northeast Pacific. Almost 90 per cent dex- I : | ;tral specimens were recorded by Jarman (1962) off Newport, 'Oregon. This evidence suggests that at least the upper ! ; IQuinault Formation is of Middle Pliocene age. Aside from the 2 species just described, the planktonic assemblage in j ,the Quinault is almost identical to that of the Montesano ^Formation. ! Several species of benthic foraminifera typical of the Quinault, but not recorded from the Montesano Formation, i : 1 |are given in the following list. , i I Buccella tenerrima ! Cassidulina limbata Cibicides mckannai suppressus ! Elphidiella hannai j Uviaerina iuncea j ! i These are commonly present in Pliocene and younger strata | i I i lalong the West Coast. The fauna of the Quinault Formation | is definitely younger than any observed in the Montesano. ; Correlation Suggested correlations between the Montesano Formation jand other formations in Washington, Oregon and California j will be discussed below. Only selected units will be treated. It is unrealistic to attempt a consideration of i ! iall possible strata. Discussions will follow in geographic order from north to south. i i j : [Washington i I I i Certain nonmarine strata to the southeast of the out- I ; i crop area of the Montesano Formation are probably correla- ! Itive with it. The Wilkes Formation was described by Roberts j (1958) for more than 760 feet of fluvial, lacustrine, and |brackish-water deposits in the vicinity of Castle Rock and Toledo. It rests upon Middle (?) Miocene basalt considered 1 I [equivalent to the Astoria Formation. Plant remains from j the lower part of the Wilkes Formation were assigned a Late j [ ! ; i Miocene age and correlated with floras from the Latah For- j mation of eastern Washington and the Mascall Formation of | | eastern Oregon. The large amount of ash and other pyro- | I I clastic debris in the Wilkes Formation further suggests a I correlation with the Montesano Formation. ! I j An unnamed unit similar to the Wilkes Formation was i reported cropping out near Centralia and Chehalis, to the north of Castle Rock, by Snavely, .et _al. (1958) . i {Oregon ; The Empire Formation is composed of a moderately thick i [section of sandstone containing an excellent megafauna. It |crops out near the mouth of Coos Bay, Oregon. Weaver (1944) considered the formation to be largely Early and Middle Pliocene in age and to be equivalent to the upper Montesano I ‘ Formation and lower Quinault Formation. The determination ! was based upon molluscan and echinoid remains; this investi- I jgator knows of no reports of foraminifera from the formation. From the evidence available to the writer, at this time it is not possible to establish the relationship between the Montesano and Empire Formations. : I i ] i j Northern California ; ; ! Undoubtedly there are many formations, marine and non- | i marine, in northern California that are equivalent to the j i I I ! Montesano Formation. In a great number of cases, data are j i i not yet sufficient to decide definite correlation. At the ! present time, this writer can suggest relationships only i on the basis of foraminiferal assemblages. Many previous I ' ! ! i correlations were made upon the megafauna. i 1 | As previously noted the megafauna of the Montesano j I jFormation has been correlated with the fauna of the San i 1 i iPablo Formation. The latter crops out in the hills along i Ithe northeast side of San Francisco Bay and is composed of 1 \ 2 members, the Cierbo Sandstone and the overlying Neroly i ________ __ i 255 | i ; jFormation. Kleinpell (1938) placed the San Pablo within ;his Delmontian Stage. The San Pablo Formation conformably overlies the Briones Sandstone considered by Kleinpell to ; j be Mohnian. Thus, on foraminiferal evidence the Montesano Formation is considered correlative at least in part to the ; Briones Sandstone and the San Pablo Formation. | The most distinctive foraminifera in the Montesano jFormation are typical of Kleinpell's Delmontian Stage of ;the Upper Miocene. The type area for this stage is in the jhills south and east of Monterey and Del Monte, California j (Kleinpell, 1938). There, the Upper Miocene beds are mapped^ ; i j I :as part of the Monterey Formation. I I I jSouthern California j ; | ; i Kleinpell (1938) has pointed out that many local names i have developed for various portions of the Monterey Forma tion in California. Two of these, the Reef Ridge Shale and | i the McLure Shale, occur in the subsurface beneath the j i ; | jdettleman Hills and in adjacent outcrops along the southwest] i j Side of the San Joaquin Valley (Woodring, .et aJL. , 1940) . jForaminiferal assemblages from the Reef Ridge Shale and to j ; i some extent the McLure Shale display a high degree of simi- i ! larity to those observed in the Montesano Formation. 256 Kleinpell considers foraminifera from the Reef Ridge Shale ! icharacteristic of his Bolivina obliqua Zone of the lower ! Delmontian. ! | The Sisquoc Formation of the Santa Maria District con tains a foraminiferal assemblage which in most respects is Jlike that of the Montesano Formation. The same is approxi mately true for the overlying Foxen Mudstone; foraminifera I from the underlying upper Monterey Formation also demon- jstrate slight similarity to the Montesano Fauna. Woodring I land Bramlette (1950) considered foraminifera from the Sis- Iquoc Formation representative of the Bolivina obliqua Zone | I | and indicative of a correlation with the Reef Ridge Shale. i However, on the basis of the megafauna these authors con- I j | eluded that the Sisquoc Formation was in part uppermost | | Miocene but mostly Lower and Middle Pliocene. i Similarity between the foraminifera of the Montesano 1 Formation and Upper Miocene units of the Los Angeles Basin j and surroundings is not as great as in the previously de- ! ! iscribed areas. This is probably the result of the presence I I !of a higher percentage of warm tolerant species in southern | i California strata. Nevertheless, many of the definitive j i ! Montesano species carry through. Rotorbinella (?) crarvey- i iensis was originally described from deposits in the Los ! 257 I I ! jAngeles Basin (Natland, 1938). In that area Wissler (1943) i Jused the species to define the latest Miocene in subsurface I | ; isections (Wissler1s Division A of the upper Delmontian). I j iRotorbinella (?) garveyensis has also been reported from i ' the upper Mohnian part of the Modelo Formation in the Santa : Monica Mountains (Pierce, 1956). The uppermost part of that i iformation in Topanga Canyon of the latter mountains was I ! I taken as the type area for the Bolivina obliqua Zone of the , jlower Delmontian (Kleinpell, 1938). A foraminiferal assem- ! l i j jblage, referred to the .B. obliqua Zone, was reported by j j i Woodring, et aJL. (1946) from the Malaga Mudstone of the i I ; I I i ! iPalos Verdes Hills. j i I Summary and Conclusions j : i s i Previous estimates of the age of the Montesano Forma- ' tion have ranged from Middle Miocene to Middle Pliocene : ! (Fig. 62). The latest published statement indicated it ! ranged from latest Miocene to Middle Pliocene (Weaver, |1944). These early determinations were based primarily i upon molluscs and other marine megafossils with some addi- ! Stional information from plant remains. I Foraminifera, previously unreported from the Montesano, i ! jwere observed in abundance and in good preservation during Fig. 62.— Previous age determinations of the Montesano ormation. AGE MIOCENE PLIOCENE CO m AUTHOR C r~ ro Weaver, 1912 Arnold and Hannibal, Weaver, Hertlein and Crickmay, 1 9 2 5 Etherington 1931 Weaver, 1937 Weaver, 1 9 4 3 Weaver, 1 9 4 4 This Paper 6SZ 260 | s the course of the present investigation. Eighty-four spe- jcies and subspecies of benthic and planktonic foraminifera ! ' jare here reported from the formation. The best assemblages j | I I j Iwere observed in the Middle Fork, Wishkah River section, 1 i i particularly the upper part, and in a laminated mudstone i i ; junit along the middle portion of the West Fork of the Sat- sop River. j Planktonic foraminifera occur in low numbers in the ; | Montesano Formation; a total of 8 species have been identi- i I ! jfied. However, none is of much value in establishing its j |aqe. At best a lower limit is set at late Middle Miocene. | i ! I Although few of the Montesano benthic foraminifera are j : j particularly useful for determining narrow age limits, j j Iseveral diagnostic forms are present. These indicate that j j Wissler's Rotorbine11a (?) garveyensis Zone of the late ! | i Delmontian is represented in the top 500 feet of section on j 'the Middle Fork of the Wishkah River (Fig. 63). The under- I I lying 400 feet contain an assemblage referrable to Klein- I ipell's early Delmontian Bolivina obliqua Zone. The pres- j ience of Hanzawaia illingi suggests that the lower part of i jthe Montesano Formation is at least in part late Mohnian. I ; No typical Early Pliocene foraminifera were encountered. [ |in the Montesano. That is to say, none of the species Fig. 63.— Idealized columnar section illustrating the stratigraphic relationships between the Quinault, Montesano, and Astoria Formations in Grays Harbor Basin. The absolute jdating and framework of Epochs and Ages are from Evernden, et al. (1964). 10° YEARS 0LIG 0 PLIOCENE EPOCH AQUI- TANIAN E U R O P E A N ACE VIND0B0N1AN SARMATIAN CALIFORNIA FORAMINIFERAL ACE SAU- CESIAN RE- LIZIAN MOHNlAN REPETTIAN LUISIAN DELMONTIAN IE N T H IC FOR AMINIFERAL ZONE i'MONTESANO,'V“ c ■ » r » ® * * • o * * m - » ® ■ < a - H O - o > n * c r * > •" * B JO 263 j I typical of Natland's Repettian Age of California is known | jto be present. It might be argued that this is the result j ; |of zoogeographic differences; however, modern foraminiferal ! i ! jfaunas between southern California and the Northwest display a high degree of similarity. Ingle (1962) in a critical I | review of the classic controversy over the placement of the ; i JYLiocene-Pliocene boundary in the southern California Ter- i ; jtiary section has recommended that it be placed between the ' Mohnian and Delmontian Stages. His decision was based upon ' jevidence from planktonic foraminifera and radiolarian assem-j ' I blages. The fact that Montesano foraminifera are considered} I i ; largely Delmontian and that megafaunal determinations have been Pliocene indicate it is entirely possible for the ! i | boundary, in the sense used by Ingle, to be in the Montesanoj Formation. However, present evidence is inconclusive. Resolution of the Miocene-Pliocene boundary problem in the j I Northwest Tertiary section must await further study. Benthic foraminifera from the stratigraphically highest i beds of the Astoria Formation below the Montesano Formation j I 1 isuggest a correlation with the lowermost Relizian Stage of jCalifornia (Fig. 63). The known ranges of 2 planktonic | j jforaminifera, Globorotalia scitula oraescitula and Globo- j i I guadrina tripartita tripartita. indicate that the lowest beds referrable to the Astoria Formation in Grays Harbor jBasin are lowermost Aquitanian of the European time scale. |The planktonic species further indicate that the highest ; j jAstoria faunas studied in this investigation may be middle j j iBurdigalian. Since there are more strata above the latter point, the formation may range into the upper Burdigalian. : No faunas of Luisian affinities from Grays Harbor Basinj i i j | jare known to this writer. A suggested time break, which may j i 'span from latest Relizian to earliest Mohnian, is commensur- i ; ate with the large unconformity beneath the Montesano For- mation. j i j Only a few species of foraminifera are considered com- | i i mon to both the Astoria and Montesano Formations. i I The Quinault Formation is physically isolated from the i jMontesano Formation so that physical stratigraphic relation-! i ships cannot be traced out. Planktonic foraminifera from | I ; | the Quinault indicate that it is Lower to Middle Pliocene I I i : I (Fig. 63). This is based upon the consistent presence of [Globorotalia puncticulata and typical forms of Globicerina I ipachyderma which coil sinistrally an average of 80 per cent ;of the time . ! A large percentage of benthic foraminifera are common ! i i ! |to both the Quinault and Montesano Formations. Nevertheless ! ' 265 I j j there are typical Pliocene or younger species in the Quin ault which were not found in the Montesano. The benthic foraminifera of the Montesano Formation ; j j ! ! Indicate a correlation at least in part with the following California units: the Briones Sandstone and San Pablo For- i Imation, San Francisco Bay area; upper Monterey Formation, Monterey area; Reef Ridge Shale and McLure Shale, Kettleman : Hills; Sisquoc Formation, Santa Maria area; upper Modelo jFormation, Los Angeles Basin. i \ 1 i | j Paleoecology I Introduction ; i ; I j Paleoecology has rapidly grown into one of the more j i | jimportant fields of study in geology. It is an indispens- I ; able aid in the search for petroleum resources, for the i solution of stratigraphic problems in general, and the in- j [terpretation of geologic history. Many different groups of prganisms can be used to identify environments. Foramini fera have been demonstrated to be most valuable for this i j purpose in marine and near-marine environments. This is j jtrue because they often occur in large numbers; are micro scopic, necessitating only small samples; are diverse; have 266 j I world-wide distribution; and possess preservable shells withj I (distinctive morphology. The remains of these animals have | been relied upon extensively in the present report. How- ; I : j (ever, miscellaneous other microfossils and molluscs lend j ! I 1 i (supporting evidence. ! Before paleoenvironments can be adequately interpreted,! I a firm knowledge must be had of modern ecologic relation- j |ships in as many diverse environments and geographic areas ias possible. Since the pioneering work of Natland (1933) ; 1 (many investigators on the foraminifera have been and con- j : I itinue to be striving to attain such knowledge. The more j I | significant studies of this nature are summarized by Phleger (I960) and Bandy and Arnal (1960). Recent investigations in the southern California area j (have clearly demonstrated the application of quantitatively j i i based distributional trends in modern foraminifera to the i j paleoecology of Tertiary sections (Bandy and Arnal, 1960; ilngle, 1962; Bandy and Kolpack, 1963). Interpretations were) i j (greatly facilitated by the wealth of refined data that have j ! i |been accumulated for modern faunas in that area (see Ingle, I i |1962). Although preliminary studies by Bandy (1953) off San Francisco; Enbysk (1960) off Oregon, Washington and I jnorthward to the Arctic; and Jarman (1962) off the central jOregon Coast, do not contain the detail of those off south ern California, general trends are available for comparison . j | I Distributional trends in modern foraminifera are often I [associated with variations in water depth. Bathymetric ; j zonations are established. However, associated with in creasing depth there is a decrease in bottom water tempera- j jture. Temperature has been considered by many to be one of I |the prime controlling factors in faunal distributions (Gun- ; j I iter, 1957). The change of faunas and floras from the equa- ' i I I [ itor to the poles is indeed striking; however, other factors j ! I : i contribute in varying degrees to the zonation. Increasing j : . i Idepth in the sea implies increasing distance from shore wrtlj ! j the rate of change varying considerably from area to area. This in turn affects the rate of sedimentation and the i i character of the sediment. Coupled with these changes and i of equal or greater importance depending upon the area and type of organism are, to name a few: Pressure, the amount and type of food, oxygen content, and salinity. Summaries of views on environmental controls of foraminifera can be j ! ‘found in Phleger (1960), Bradshaw (1961), and Loeblich and I ■Tappan (1964). The effects of these variables will be i lexamined wherever they apply in the following discussion; | Ihowever, emphasis will be placed upon paleobathymetry. 268 j and paleotemperature. Recently, it was discovered that many bathyal species of foraminifera have similar upper depth jlimits in entirely different oceanic areas such as the ^ jAntarctic and the Gulf of Mexico (Bandy and Echols, 1964). ; 'Temperature and substrate play minor roles in these cases. i j I Paleoecologic studies of the Montesano Formation have ! jbeen based primarily upon sections along the Middle Fork of s I _ : |the Wishkah River, the West Fork of the Satsop River, and the Canyon River. The best and most complete collections j land the clearest stratigraphic relationships were obtained | ■from them. In general, patterns from other sections displa^ I j j j roughly the same trends. Differences can be explained 'largely by too widely spaced samples, poor preservation, j | j lor structural and, therefore, stratigraphic uncertainty. | 1 I | j 'Significant differences from these other sections and mis cellaneous other areas in Grays Harbor Basin will be exam ined as they apply in the following discussion. ] I Foraminifera i Species Composition i i I Studies of modern foraminifera distribution have dem- ) j i jonstrated an orderly succession of faunas from the shore to ! 269 j I deep water. Workers in various parts of the world have jestablished bathymetric zones based upon faunal assemblages.: j ' j 1 jln the Gulf of California, for example, Bandy (1961) recog- j jnized 17 faunal groups representing 8 bathymetric zones from I | a lagoon to a depth of more than 9,000 feet. Although depth jlimits and species involved are somewhat different from area! !to area, Phleger (1960) concluded that boundaries at approx- i j jimately 65 feet, 165 feet, 350 feet, 650-1,000 feet, 1,300- 1650 feet, 3300 feet, 6,500 feet, and possibly 23,000 feet j ! jhave generally world-wide occurrence. Furthermore, Bandy j ! i (1960c) states: j | ! Bathyal species of the tropics do not become shelf ; species of the cold temperate and polar regions; con- ! versely shelf species of polar regions have related j j forms in the shelf areas of the tropics. j i Over the last 100 years conflicting concepts and ter- | minology have developed regarding the classification of the ; | sea floor into major bathymetric environmental realms. ! iHedgpeth (1957) contains a classification scheme resulting jfrom attempts to standardize usage. It will be used in thisi jpaper with modifications after Bandy (1961) (Table 8). Modern techniques for identifying the presence of ! protoplasm in the tests of foraminifera (Walton, 1952) have jenabled the establishment of definite living ranges. I TABLE 8 DEPTH CLASSIFICATION OF BENTHIC MARINE ENVIRONMENTS j Littoral i Intertidal 1 1 Inner Sublittoral 0- 165 feet Outer Sublittoral 165- 650 feet ; j 1 j Upper Bathyal 650- 2,000 feet 1 i Middle Bathyal 2,000- 8,000 1 feet ; Lower Bathyal 8,000-13,000 feet ! Abyssal 13,000-17,000 i feet i Hadal Deeper than 17, 000 Studies of fossil material involve not only forms that lived jat the site of deposition but also those displaced from ) i other areas, usually shallower environments, plus reworked i | land relic elements. Displaced shallower forms may be ac counted for, if the minimum depth of deposition for the fauna is based upon the upward limit of the deepest living i ; species. The assumption is made that displacement of spe- l i j ' jcies into shallower depths is seldom, if ever, the case. | | [This is valid except for paralic areas where wave turbulence! S ! land tidal currents may combine to produce such a situation. | ! i For example, it has been demonstrated that at Yaquina Bay, I Oregon during at least part of the year there is movement | pf nearshore marine deposits into the bay (Kulm and Byrne, j ! 1964). Rare instances may occur in deeper water areas I I where such processes as animal activity and upwelling may ; cause displacement into shallower water. Reworked foraminifera can often be distinguished by their different state of preservation. Also, admixtures of assemblages from strata of widely different ages are easily j ■recognized. In addition to age differences, reworked faunas i i are frequently representative of environments distinctly i different from those of the indigenous faunas. i | In areas of non-deposition, relict faunas may be L___________________________________________________________________________ 272 I i present at or near enough to the surface to be included withi indigenous forms. Glauconite, phosphorite and concentrated I 'shells are often associated with relict faunas. Normally j i ! ; ( jlarge time differences are not involved but different bathy-j jmetric and zoogeographic assemblages may be. i As a result of evolution it is not possible to make jdirect application of modern assemblage zones to fossil j strata. Although absolute depths cannot be assigned, the ! ! iuse of homeomorphic and isomorphic relationships (Bandy and ! i 1 I jArnal, 1960) have yielded remarkably similar trends. Prob- j ’i I ; lems of speciation are minimized by considering the corre- j i I ilation of foraminiferal morphology with environment (Bandy, ; . i jl960c). | ! I i ' | It is often neither realistic nor possible to attempt i ! las fine a bathymetric subdivision of fossil faunas as Recent, ones for the reasons discussed above. In addition, much ofJ the fauna may be destroyed by post-depositional processes. ;The thin-walled arenaceous species which occur in large j I ;numbers in many inner sublittoral areas are seldom pre served. Even more sturdy forms may be destroyed or damaged 1 Jbeyond adequate recognition by diagenesis and weathering, jparticularly in permeable sandstone. 273 I Wishkah River Sections ' Four paleobathymetric foraminiferal faunas are recog nized in the Montesano Formation along the Middle Fork of ! j I jthe Wishkah River (Table 9). These indicate benthic marine 1 environments ranging from the inner sublittoral zone to the : i ; middle bathyal zone. Various conditions at the basal con- i ! jtact, as discussed earlier, and molluscan fossils in the j l ; ibasal sandstone of the formation, to be treated more fully slater in this paper, indicate that initial sedimentation | ! jtook place in the littoral zone. The occurrence of these j 1 ? jfaunas in regular succession upsection (Fig. 64) reflects j I | a gradual increase in the depth of water in which the for mation was deposited. i I I The lower sandstone member of the Montesano is domin- j ated by faunas I and II, characterized by Buliminella ele- | ! qantissima and Nonionella spp. respectively. There is con- ! ! ! isiderable local variation in the percentage of these 2 groups present in each sample. These are interpreted as ^indicating either changes in the rate of supply of sediment i to the edge of a uniformly subsiding basin or variations in ; j ! i jthe rate of subsidence. The factors are closely interrela- ! j jted and probably were both operative. The only major break, 274 I TABLE 9 PALEOBATHYMETRIC FORAMINIFERAL FAUNAS FROM THE MONTESANO FORMATION I. Buliminella eleaantissima Fauna: 0-150 feet, 10°—15° C Bolivina advena striatella Bolivina vauahani Buccella friaida Buliminella elegantissima Cibicides fletcheri Cibicides lobatus Elphidium orbiculare Ouinqueloculina akneriana bellatula Ouinqueloculina seminula II. Nonionella Fauna: 150-650 feet, 7°-10° C Anguloaerina anaulosa Buliminella curta Cassidella subplana Cassidulina minuta Cassidulina modeloensis Epistominella bradvana Globobulimina ovula Globobulimina Pacifica Hanzawaia illinai Haplophracrmoides columbiense Nonionella scapha basispinata Nonionella lunata Nonionella miocenica III. Bolivina Fauna: 650-2,000 feet, 5°-7° C Bolivina marainata monicana Bolivina obliqua Bolivina rankini T A B L E 9 — C o n t i n u e d B u l i m i n a a f f i n i s C a s s i d e l l a c a l i f o r n i e n s i s c a l i f o r n i e n s i s C a s s i d e l l a c a l i f o r n i e n s i s t i c e n s i s C a s s i d u l i n a l a e v i g a t a C a s s i d u l i n a m o d e l o e n s i s ( k e e l e d f o r m ) Cibicides mckannai E p i s t o m i n e 1 1 a c a r i n a t a p a c i f i c a E p i s t o m i n e l l a e x i a u a U v i a e r i n a h o o t s i h o o t s i U v i g e r i n a h o o t s i m o d e l o e n s i s U v i g e r i n a s u b o e r e a r i n a I V . U v i a e r i n a p e r e q r i n a h i s p i d o c o s t a t a F a u n a : 2 , 0 0 0 - 8 , 0 0 0 f e e t , 2 ° - 5 ° C B u l i m i n a s u b a c u m i n a t a C a s s i d u l i n a d e l i c a t a C a s s i d u l i n o i d e s c o r n u t a E p i s t o m i n e l l a c a r i n a t a s m i t h i L o x o s t o m u m b r a m l e t t i R o t o r b i n e 1 1 a ( ? ) g a r v e y e n s i s S p h a e r o i d i n a v a r i a b i l i s U v i a e r i n a p e r e a r i n a h i s p i d o c o s t a t a P i g . 6 4 . — D i s t r i b u t i o n o f p a l e o e c o l o g i c p a r a m e t e r s t h r o u g h t h e M o n t e s a n o F o r m a t i o n , M i d d l e F o r k , W i s h k a h R i v e r t r / \ I •IA TO M H V H M R ST iT O U T H P b M L C O V A T N T M tT R Y H , ! 277 i n a n o t h e r w i s e u n i f o r m c h a n g e i n f a u n a s t h r o u g h t h i s m e m b e r , o c c u r s i n s a m p l e W K - 1 8 . A t t h a t p o i n t f a u n a I i s t h e o n l y o n e p r e s e n t . I t m u s t b e p o i n t e d o u t t h a t f o r a m i n i f e r a I '' I jin t h i s p a r t o f t h e s e c t i o n a r e o f t e n t o o r a r e a n d t o o p o o r l y p r e s e r v e d t o a l l o w c o m p l e t e c o n f i d e n c e i n p e r c e n t a g e s j ; j o b t a i n e d . T h e r e i s s o m e d i s p l a c e m e n t o f f a u n a s w h i c h m u s t j I ; j : j a l s o b e c o n s i d e r e d . T h e o v e r - a l l p a t t e r n i n t h e l o w e r m e m - ; i | ! jber i n d i c a t e s a g r a d u a l , t h o u g h i r r e g u l a r , i n c r e a s e i n d e p t h ! ! i |of w a t e r f r o m 0 t o a b o u t 8 0 0 f e e t ( F i g . 6 4 ) . i | i T h e u p p e r m e m b e r c o n t a i n s m o r e d i v e r s i f i e d f o r a m i n i - | i ; : j f e r a l a s s e m b l a g e s r e p r e s e n t a t i v e o f a l l o f t h e p a l e o b a t h y - j ! ! | ! t n e t r i c f a u n a s . A l t h o u g h f a u n a I I I (B o l i v i n a s p p . ) c o m p r i s e s o n l y u p t o 1 0 p e r c e n t o f t h e t o t a l f o r a m i n i f e r a l a s s e m b l a g e i n t h e l o w e r m e m b e r , i t r a p i d l y i n c r e a s e s i n i m p o r t a n c e a t t h e t r a n s i t i o n b e t w e e n t h e 2 m e m b e r s a n d b e c o m e s t h e o v e r - j I a l l d o m i n a n t g r o u p t h r o u g h o u t t h e u p p e r m e m b e r . F a u n a I I I ! i s m o s t c h a r a c t e r i s t i c a l l y f o u n d i n t h e l o w e r 3 0 0 f e e t o f t h e u p p e r m e m b e r w h e r e a m a x i m u m o f 8 8 p e r c e n t i s r e a c h e d ! ! jin s a m p l e W K - 2 6 . F a u n a I V (U v i a e r i n a p e r e a r i n a h i s p i d o c o s - | j t a t a ) g r a d u a l l y i n c r e a s e s i n a b u n d a n c e t h r o u g h m o s t o f t h e j | i t o p 7 0 0 f e e t o f t h e f o r m a t i o n ; a m a x i m u m o f 3 7 p e r c e n t i s p r e s e n t i n s a m p l e W K - 3 7 . T h e d e c l i n e i n t h e p e r c e n t a g e o f j j F a u n a I V n e a r t h e t o p o f t h e M o n t e s a n o i s c o n s i d e r e d t h e 279 r e s u l t o f m a s k i n g b y d i s p l a c e d q u a n t i t i e s o f f a u n a s I, I I a n d I I I . T h e 2 a r e a s o f i n c r e a s e d p e r c e n t a g e s o f f a u n a s I l a n d I I i n t h e u p p e r m e m b e r ( F i g . 6 4 ) p r o b a b l y r e s u l t e d f r o m ; j f a u n a l d i s p l a c e m e n t . T h e t r e n d t o w a r d i n c r e a s i n g w a t e r s i d e p t h t h r o u g h t h e l o w e r m e m b e r i s d e m o n s t r a t e d b y t h e s u e - ' i ! I j c e s s i o n o f f a u n a s c o n t i n u i n g i n t o t h e u p p e r m e m b e r . T h e | I j i n c r e a s e i n s u g g e s t e d d e p t h i s a t f i r s t r a t h e r r a p i d , c h a n g - j I , j j i n g f r o m a b o u t 8 0 0 t o 2 , 0 0 0 f e e t ; t h e n i t s l o w s f o r a s p a n , ^ j a n d f i n a l l y i n c r e a s e s m o r e r a p i d l y a g a i n t o a m a x i m u m d e p t h j o n t h e o r d e r o f 3 , 5 0 0 f e e t . T h e s a m e g e n e r a l p a t t e r n o f I j f a u n a l s u c c e s s i o n a n d t h e r e f o r e i n c r e a s i n g w a t e r d e p t h i s I ^ e v i d e n t i n t h e 3 o t h e r s e c t i o n s e x a m i n e d i n t h e n o r t h e r n W i s h k a h a r e a ( s e e T a b l e 3 ) . j I i W e s t F o r k , S a t s o p R i v e r a n d C a n y o n R i v e r S e c t i o n s i 1 I T h e l a m i n a t e d s h a l e u n i t o n t h e W e s t F o r k o f t h e S a t - j s o p R i v e r c o n t a i n s p r e d o m i n a n t l y f a u n a s I a n d I I I ( F i g . | 6 5 ) . F a u n a I I c o m p r i s e s o n t h e a v e r a g e o n l y 1 0 p e r c e n t o f | i ! ! t h e f o r a m i n i f e r a l p o p u l a t i o n . D i s t i n c t i o n b e t w e e n f a u n a s I i jll a n d I I I a s h e r e i l l u s t r a t e d d e p e n d s l a r g e l y u p o n r e l a t i v e p e r c e n t a g e s o f E p i s t o m i n e l l a b r a d v a n a a n d E . e x i g u a . I T h e s e p a r a t i o n o f t h e s e t w o s p e c i e s i s n o t a l w a y s a c l e a r ! F i g . 6 5 . — D i s t r i b u t i o n o f p a l e o e c o l o g i c p a r a m e t e r s t h r o u g h t h e l a m i n a t e d m u d s t o n e u n i t , M o n t e s a n o F o r m a t i o n , W e s t F o r k , S a t s o p R i v e r . ISIS m COLUMNAR S E C T I O N S'. • - « = s: s s = 8 8 rS AA-A.M.A/> A-AA '-vJMCMW* j S A M P L E NUMBER (UW«- ) ^ f x * . -^^. a a a A— c ^-4i i > I n > lie r ■* S P E C I E S - 3 N U M B E R 8 183 282 1 o n e ; h o w e v e r , m o s t s p e c i e s e n c o u n t e r e d h e r e a r e d e f i n i t e l y j r e f e r r a b l e t o E,. e x i a u a . a f o r m m o s t c h a r a c t e r i s t i c o f t h e ! j u p p e r b a t h y a l z o n e ( B a n d y , 1 9 6 1 ) . M o s t t y p i c a l s p e c i e s o f j | I i ! f a u n a I I I ( s e e T a b l e 9 ) a r e n o t f o u n d i n l a r g e n u m b e r s i n | ' t h i s s e c t i o n . T h e p r e s e n c e o f E p i s t o m i n e l l a e x i a u a . E . c a r -j i - ! i ; i i n a t a p a c i f i c a . a n d C a s s i d e l l a c a l i f o r n i c a t i c e n s i s c o n s t i - J ! i ! t u t e s t h e p r i n c i p a l c r i t e r i o n f o r i d e n t i f i c a t i o n o f f a u n a j ! ! ! i | I I I a l o n g t h i s t r a v e r s e . T h e f a u n a i s m o s t p r o n o u n c e d i n J i i t s d e v e l o p m e n t b e t w e e n s a m p l e s M W S - 1 0 a n d 1 9 w h e r e i t c o n - | I j j s i s t e n t l y e x c e e d s 5 0 p e r c e n t o f t h e t o t a l p o p u l a t i o n o f j I j | f o r a m i n i f e r a . A r a t h e r s h a r p t r a n s i t i o n b e t w e e n t h e d o m i - i j i i n a n c e o f f a u n a s I a n d I I I r e s p e c t i v e l y o c c u r s i n t h e v i c i n - ! : i t y o f s a m p l e M W S - 1 0 ; a m o r e g r a d u a l c h a n g e c e n t e r s a r o u n d i s a m p l e M W S - 2 0 . B e c a u s e o f t h e p r e v i o u s l y d i s c u s s e d s t r u c - I i t u r a l a n d s t r a t i g r a p h i c u n c e r t a i n t i e s u p s t r e a m f r o m s a m p l e i I I M W S - 2 3 ( s e e F i g s . 4 6 a n d 4 7 ) , f a u n a l d i s t r i b u t i o n s a r e j i p l o t t e d s e p a r a t e l y f o r i n d i v i d u a l p o r t i o n s o f t h e s e c t i o n . ! j T h e f r e q u e n t v a r i a t i o n s i n p e r c e n t a g e o f t h e v a r i o u s f a u n a s i c o u l d i n d i c a t e r e p e t i t i o n o r o m i s s i o n b y f a u l t i n g , o r r e a l i j c h a n g e s i n e n v i r o n m e n t e i t h e r s t r a t i g r a p h i c a l l y o r a r e a l l y . j R e g a r d l e s s o f t h i s d e g r e e o f u n c e r t a i n t y , t h e m a j o r p a l e o - j ■ e n v i r o n m e n t a l p i c t u r e i s n o t a l t e r e d a p p r e c i a b l y . I I T h e p r e s e n c e i n s i g n i f i c a n t p e r c e n t a g e s o f 2 s p e c i e s 283 ! I 1 m a k e s p o s s i b l e t h e d e l i n e a t i o n o f a f a u n a u n r e c o g n i z e d i n t h e n o r t h e r n W i s h k a h a r e a . I t i s c h a r a c t e r i z e d b y M i l i - i I a m m i n a f u s c a a n d E l p h i d i u m r u a u l o s u m . T h e f o r m e r i s a d o m - i t I I ; i n a n t a n d g e n e r a l l y r e s t r i c t e d b r a c k i s h w a t e r s p e c i e s ( H e d - I ' b e r g , 1 9 3 4 ; P h l e g e r , 1 9 6 0 ; B a n d y , 1 9 6 3 ) . S m a l l , r a t h e r j n o n d e s c r i p t s p e c i e s o f E l p h i d i u m . s u c h a s t h e o n e r e f e r r e d !t o h e r e , a r e c h a r a c t e r i s t i c a l l y o b s e r v e d i n i n n e r s u b l i t t o r - r j i jal t o b r a c k i s h w a t e r e n v i r o n m e n t s ( B a n d y , 1 9 6 1 ) . F o r c o n - j i ] i v e n i e n c e t h i s f a u n a w i l l b e t e r m e d s i m p l y " b r a c k i s h . " I t i ; j m a k e s u p a v a r i a b l e p e r c e n t a g e o f t h e t o t a l p o p u l a t i o n , j g e n e r a l l y p a r a l l e l i n g t h e a b u n d a n c e o f f a u n a I. A m a x i m u m j i ! l v a l u e f o r t h e b a s a l p o r t i o n o f t h e u n i t o f 1 4 p e r c e n t i s j r e a c h e d i n s a m p l e M W S - 5 . A l m o s t c o m p l e t e d o m i n a n c e o f t h e i | j 1 f a u n a b y t h e 2 s p e c i e s w a s o b s e r v e d i n 3 s a m p l e s , a l l f r o m i i i i . j !t h e p o o r l y s o r t e d c h a n n e l - f i l l i n g s e d i m e n t s d i s c u s s e d e a r - j l i e r ( F i g . 6 5 ) . ! : j C o n s i d e r i n g t h e d e e p e s t - o c c u r r i n g e l e m e n t s i n t h e | i i i b e n t h i c f o r a m i n i f e r a a s s e m b l a g e , w a t e r d e p t h s d u r i n g d e p o - j i i i j s i t i o n w e r e , a t a m i n i m u m , o n t h e o r d e r o f 1 , 0 0 0 f e e t . T h e ; j h i g h p e r c e n t a g e o f f a u n a I a n d o f t h e " b r a c k i s h " f a u n a i s c o n s i d e r e d t o b e t h e r e s u l t o f d i s p l a c e m e n t . I ! T h e r e i s s o m e e v i d e n c e t h a t f a u n a I I I i s i n d i c a t i v e o f i j o n l y t h e s i l l d e p t h o f a d e e p e r b a s i n . H a r m a n ( 1 9 6 4 ) n o t e d I t h a t s e v e r a l n o r m a l l y r a r e s p e c i e s i n t h e f a u n a s o f f s o u t h - ■ I j e r n C a l i f o r n i a o c c u r r e d i n h i g h p e r c e n t a g e w i t h i n S a n t a I | i i B a r b a r a B a s i n . T h e s p e c i e s r e p r e s e n t e d a h i g h l y s p e c i a l i z e d ! ! I j f a u n a a b l e t o w i t h s t a n d t h e l o w o x y g e n a t e d c o n d i t i o n s p r e s e n t i n t h i s r e s t r i c t e d b a s i n . M e m b e r s o f t h e f a u n a h a v e a i g e n e r a l l y i m p o v e r i s h e d a p p e a r a n c e w i t h t h i n , f r a g i l e t e s t w a l l s ; s m a l l e r t h a n n o r m a l t e s t s ; a n d n o s u r f a c e o r n a m e n t a - ; [ ; f i ! t i o n . O n e o f H a r m a n ' s i n d e x f o r m s o f l o w o x y g e n a t e d e n v i r o n m e n t s i s B o l i v i n a s e m i n u d a . I t i s n o t e w o r t h y t h a t t h e i i j j o n l y o b s e r v e d o c c u r r e n c e s o f t h i s s p e c i e s i n t h e M o n t e s a n o i I ; F o r m a t i o n a r e i n t h e l a m i n a t e d m u d s t o n e s o f t h e W e s t F o r k , j I 1 ! S a t s o p R i v e r s e c t i o n . I n a d d i t i o n , t h e o v e r - a l l f a u n a c o n - ! t a i n s s p e c i e s w i t h t e s t s s m a l l e r a n d t h i n n e r - w a l l e d t h a n | i n o r m a l . S e d i m e n t c h a r a c t e r i s t i c s t o b e d i s c u s s e d l a t e r i a l s o i n d i c a t e r e s t r i c t e d b a s i n c o n d i t i o n s . I f t h e l a m i n a t e d s h a l e u n i t w e r e d e p o s i t e d i n a s i l l e d 3 j | l o w o x y g e n a t e d b a s i n , t h e p r e s e n c e o f G l o b o r o t a l i a s c i t u l a s c i t u l a g i v e s a n i n d i c a t i o n o f a m i n i m u m d e p t h t o t h e b a s i n j i j | f l o o r . C a s e y ( 1 9 6 3 ) o b s e r v e d t h i s p l a n k t o n i c f o r a m i n i f e r ; i o n l y i n d e p t h s g r e a t e r t h a n 5 0 0 m e t e r s o f f s o u t h e r n C a l i f o r n i a . S i m i l a r f i n d i n g s w e r e r e p o r t e d b y B r a d s h a w ( 1 9 5 9 ) . I I t s h o u l d b e n o t e d f u r t h e r t h a t a m u c h w i d e r v a r i e t y o f ( " n o r m a l a p p e a r i n g " s p e c i e s w e r e o b s e r v e d i n n o n - l a m i n a t e d 285 s e d i m e n t c o n t a i n i n g G l o b o r o t a l i a s c i t u l a f r o m t h e M i d d l e F o r k , W i s h k a h s e c t i o n t h a n i n l a m i n a t e d s h a l e o n t h e W e s t i j F o r k , S a t s o p R i v e r ( c o m p a r e T a b l e s 2 a n d 4 ) . j F o r a m i n i f e r a l a s s e m b l a g e s i d e n t i c a l t o t h o s e j u s t d i s c u s s e d f o r t h e l a m i n a t e d s h a l e a r e p r e s e n t i n t h e s a n d y j m u d s t o n e f a c i e s ( u n i t 2 , F i g s . 3 4 a n d 4 3 ) o f t h e M o n t e s a n o j F o r m a t i o n m e a s u r e d s e c t i o n s o n t h e C a n y o n R i v e r a n d t h e j u p p e r p o r t i o n o f t h e W e s t F o r k o f t h e S a t s o p R i v e r . F a u n a !l i s d o m i n a n t i n a l l b u t 2 o f t h e f o r a m i n i f e r a - b e a r i n g i I ' s a m p l e s f r o m t h e C a n y o n R i v e r s e c t i o n ( F i g . 6 6 ) . T h e l o w e s t o f t h e s e i s C - 8 f r o m a t h i n m u d s t o n e b e d c o n t a i n i n g i i [ a b u n d a n t f i n e l y d i v i d e d c a r b o n a c e o u s d e b r i s a n d a l a r g e c a r b o n i z e d l o g . A t t h a t p o i n t t h e " b r a c k i s h " f a u n a c o m - , p r i s e s 3 9 p e r c e n t o f t h e t o t a l . I t i s p o s s i b l e t h a t t h i s i [ r e p r e s e n t s d e p o s i t i o n i n a l a g o o n o r e s t u a r y . T h e o t h e r d e v i a t i o n i s i n s a m p l e C - 1 4 w h e r e f a u n a I I m a k e s u p 5 8 p e r c e n t o f t h e t o t a l f o r a m i n i f e r a a s s e m b l a g e . T h e d i s t r i b u t i o n o f f a u n a s t h r o u g h u n i t 2 i n d i c a t e s j [ g r a d u a l l y d e e p e n i n g w a t e r t o p r o b a b l y t h e o u t e r p o r t i o n o f i [ t h e s h e l f w h e r e d e p t h r e a c h e d p e r h a p s 5 0 0 t o 6 0 0 f e e t o r | j l e s s . T h i s w a s f o l l o w e d b y s h o a l i n g . F i g . 6 6 — D i s t r i b u t i o n o f p a l e o e c o l o g i c p a r a m e t e r s t h r o u g h t h e M o n t e s a n o F o r m a t i o n , C a n y o n R i v e r . FIGURE 6 6 G- A- FOWLER, 1965 m 3 i O COLUMNAR SECTION SA M PLE NUMBER (C- ) S P E C IE S NUMBER o T RADIOLARIAN NUMBER ° * O 8 * 5 5 o • V S T A T O L IT H NUMBER I • ? - r 0 •290 m o ^i® 7 9 0 C-< m m H a < LQZ ! 288 S p e c i e s D i v e r s i t y J i I i | . I j T h e n u m b e r o f b e n t h i c f o r a m i n i f e r a s p e c i e s l i v i n g a t a 1 { p a r t i c u l a r l o c a t i o n i s a m e a s u r e o f h o w f a v o r a b l e t h e e n - i v i r o n m e n t i s . N u m e r o u s s t u d i e s h a v e p o i n t e d o u t t h e u s e - j i [ f u l n e s s o f t h i s p a r a m e t e r a s a n a i d t o d e l i m i t i n g e n v i r o n - j ! i m e n t a l t r e n d s ( s e e B a n d y a n d A r n a l , 1 9 6 0 ) . T h e s e h a v e d e m - I i j o n s t r a t e d t h a t , e x c e p t i n s p e c i a l i z e d c a s e s , t h e n u m b e r o f i | I s p e c i e s g r a d u a l l y i n c r e a s e s f r o m t h e s h o r e t o t h e u p p e r j I i I b a t h y a l z o n e a n d t h e n o f t e n t e n d s t o d e c r e a s e i n t o d e e p e r j i I I z o n e s . i | G r e a t e s t s p e c i e s d i v e r s i t y i n t h e M o n t e s a n o F o r m a t i o n ! w a s o b s e r v e d i n t h e u p p e r m e m b e r o n t h e M i d d l e F o r k o f t h e j W i s h k a h R i v e r . T h e r e a m a x i m u m o f 4 8 s p e c i e s w a s r e c o r d e d ! ( F i g . 6 4 ) . T h e n u m b e r a v e r a g e s m o r e t h a n 2 5 p e r s a m p l e t h r o u g h t h e u n i t . T h e c o n s i d e r a b l e v a r i a t i o n i n n u m b e r p r e s e n t i s t o s o m e e x t e n t t h e r e s u l t o f d i f f e r e n c e s i n d e - I g r e e o f p r e s e r v a t i o n . T h o u g h i r r e g u l a r , t h e r e i s a g e n e r a l [ t e n d e n c y f o r a g r a d u a l i n c r e a s e i n t h e n u m b e r o f s p e c i e s u p - j s e c t i o n t o s a m p l e W K - 3 3 , f o l l o w e d b y a d e c r e a s e t o w a r d t h e i t o p o f t h e s e c t i o n . T h i s t r e n d i s i n a g r e e m e n t w i t h t h e i { a s s u m e d p a l e o b a t h y m e t r i c c u r v e f o r t h e f o r m a t i o n ( F i g . 6 4 ) j l a n d c o n d i t i o n s r e p o r t e d f r o m m o d e r n e n v i r o n m e n t s . H o w e v e r , 2 8 9 j I j d a t a f o r t h e d e c r e a s e a t t h e t o p a r e i n c o n c l u s i v e . A s s o - i ; i I c i a t e d w i t h i t i s a n i n c r e a s e i n a v e r a g e g r a i n s i z e o f t h e I ( s e d i m e n t a n d a h i g h e r p e r c e n t a g e o f d i s p l a c e d f o r m s . I t i s i d e s i r a b l e t o e x a m i n e s a m p l e s f r o m h i g h e r i n t h e s e c t i o n a n d ( f r o m d e e p e r w a t e r p a l e o e n v i r o n m e n t s . T h e a v e r a g e o f 1 1 s p e c i e s p e r s a m p l e o b s e r v e d i n t h e ( l a m i n a t e d s h a l e u n i t o n t h e W e s t F o r k o f t h e S a t s o p R i v e r | | |is c o n s i d e r a b l y l e s s t h a n t h a t f r o m s a m p l e s o f p r e s u m a b l y I t h e s a m e p a l e o - w a t e r d e p t h o n t h e W i s h k a h . A m a x i m u m o f ' | i j o n l y 2 0 w a s r e c o r d e d i n t h e l a m i n a t e d u n i t ( F i g . 6 5 ) . T h i s j i ! jis c o n s i d e r e d f u r t h e r e v i d e n c e o f t h e i m p o v e r i s h e d n a t u r e | i I ! i o f t h e f a u n a a n d c o m m e n s u r a t e w i t h t h e i n t e r p r e t a t i o n o f a j ; i r e s t r i c t e d b a s i n e n v i r o n m e n t . ! i S i m i l a r l y l o w n u m b e r s a r e p r e s e n t i n l i t h o l o g i c u n i t 2 ! i ! | (on t h e C a n y o n R i v e r ( F i g . 6 6 ) . T h e r e t h e f a u n a d o e s n o t i d i s p l a y a n i m p o v e r i s h e d c h a r a c t e r a n d t h e s p e c i e s c o m p o s i t i o n r e f l e c t s i n n e r t o o u t e r s u b l i t t o r a l e n v i r o n m e n t a l I z o n e s . T h e n u m b e r o f s p e c i e s r e c o r d e d f o r t h i s u n i t i s i n i i jline w i t h t h e p a l e o b a t h y m e t r i c i n t e r p r e t a t i o n a n d w i t h n u m b e r s o f s p e c i e s o b s e r v e d i n m o d e r n s h e l f a s s e m b l a g e s . F o r a m i n i f e r a l N u m b e r F o r a m i n i f e r a l n u m b e r ( S c h o t t , 1 9 3 5 ) i s a n e x p r e s s i o n o f I 2 9 0 I | J t h e n u m b e r o f s p e c i m e n s o f f o r a m i n i f e r a p e r g r a m d r y w e i g h t j jOf s e d i m e n t . A l t h o u g h i t h a s b e e n a r g u e d t h a t a p e r - d r y - i ! I I ■ w e i g h t b a s i s i s u n s a t i s f a c t o r y f o r e c o l o g i c s t u d i e s o f i ] I J m o d e r n f o r a m i n i f e r a ( W a l t o n , 1 9 5 5 ) , t h i s i s a v a l u a b l e j i j a p p r o a c h t h a t c a n b e u s e d i n e v a l u a t i n g f o s s i l m a t e r i a l . T h e t o t a l n u m b e r o f f o r a m i n i f e r a k n o w n t o b e l i v i n g i n a g i v e n a r e a i s a m e a s u r e o f p o p u l a t i o n d e n s i t y , a n d g i v e s | i ; s o m e i n d i c a t i o n o f t h e p r o d u c t i v i t y o f t h e e n v i r o n m e n t . j H o w e v e r , t h e t o t a l n u m b e r o f t e s t s i s c o n t r o l l e d l a r g e l y b y ! I : j s e d i m e n t d i l u t i o n a n d i s t h e r e f o r e a f u n c t i o n o f t h e r a t e I 1 o f s e d i m e n t d e p o s i t i o n ( P h l e g e r , 1 9 5 1 ; B a n d y a n d A r n a l , | 1 9 6 0 ) . S t u d i e s o f m o d e r n a s s e m b l a g e s h a v e d e m o n s t r a t e d a j p r o g r e s s i v e i n c r e a s e i n s p e c i m e n a b u n d a n c e f r o m t h e s h o r e t o t h e u p p e r b a t h y a l z o n e ( B a n d y a n d A r n a l , i 9 6 0 ; B a n d y , j ; ! 1 9 6 1 ) . I n t o d e e p e r w a t e r , t h e r e i s o f t e n a d e c r e a s e i n f o r a m i n i f e r a l n u m b e r e x c e p t f o r p l a n k t o n i c o o z e s . T h e g e n e r a l d e c r e a s e , t o a l a r g e e x t e n t , r e f l e c t s l o w e r p r o d u c t i v i t y ( W a l t o n , 1 9 5 5 ) . U n d o u b t e d l y , d i l u t i o n b y d i s p l a c e d s e d - | t ! i i m e n t i s a f a c t o r i n m a n y a r e a s . F o r i n s t a n c e , i t h a s b e e n ! E x p r e s s e d b y D i e t z ( 1 9 5 2 ) t h a t t h e b u l k o f m o d e r n d e t r i t a l t n a r i n e s e d i m e n t s t e n d t o b y - p a s s t h e o u t e r e d g e o f t h e s h e l f ^ n d u p p e r p a r t o f t h e s l o p e a n d a r e d e p o s i t e d p r i n c i p a l l y I i p e a r s h o r e a n d a t t h e b a s e o f t h e s l o p e . L o w a n d q u i t e v a r i a b l e f o r a m i n i f e r a l n u m b e r s w e r e o b - i ' j t a i n e d t h r o u g h t h e l o w e r m e m b e r o f t h e M o n t e s a n o F o r m a t i o n i ' j ; | a l o n g t h e M i d d l e F o r k o f t h e W i s h k a h R i v e r ( T a b l e 2 , F i g . S ; | 6 4 ) . W i t h f e w e x c e p t i o n s , l e s s t h a n 2 0 s p e c i m e n s p e r g r a m i w e r e p r e s e n t i n t h e s a m p l e s . S i m i l a r v a l u e s h a v e b e e n r e p o r t e d b y B a n d y , e t a d . ( 1 9 6 4 ) f o r l a r g e p o r t i o n s o f t h e ! ( i n n e r a n d c e n t r a l s h e l f a r e a s o f S a n P e d r o B a y , C a l i f o r n i a . i j (The w i d e r a n g e i n v a l u e s , t o s o m e e x t e n t , i s t h e r e s u l t o f ( v a r i a n c e i n t h e d e g r e e o f p r e s e r v a t i o n . H i g h e s t f i g u r e s I ; iare a s s o c i a t e d w i t h s e d i m e n t c o n t a i n i n g l a r g e q u a n t i t i e s o f j I , s i l t a n d c l a y . j I I A l t h o u g h v a r i a b l e , a g r a d u a l i n c r e a s e i n f o r a m i n i f e r a l ; i I p u m b e r i s e v i d e n t t h r o u g h t h e l o w e r h a l f o f t h e u p p e r m e m - j | | b e r t o a m a x i m u m v a l u e o f 9 5 6 i n s a m p l e W K - 3 2 ( F i g . 6 4 ) . j T h e n u m b e r t h e n d r o p s o f f m a r k e d l y a n d g e n e r a l l y r e m a i n s j 1 l e s s t h a n 5 0 p e r g r a m i n t h e r e m a i n d e r o f t h e s e c t i o n . T h e d e c l i n e m a y , i n f a c t , b e m o r e g r a d u a l . T h i s c a n n o t b e d e t e r m i n e d b e c a u s e o f a c o v e r e d i n t e r v a l f o r 1 5 0 f e e t o f s e c - ( : I j j t i o n . I T h e p e a k i n s p e c i m e n a b u n d a n c e c o i n c i d e s r a t h e r n i c e l y | j j w i t h t h e n o t s o o b v i o u s p e a k i n t h e n u m b e r o f s p e c i e s a n d i g e n e r a l l y a g r e e s w i t h t h e p a l e o b a t h y m e t r i c c u r v e d r a w n f o r It h e f o r m a t i o n . A n i n c r e a s e i n a v e r a g e g r a i n s i z e t h r o u g h i _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 292 j t h e t o p 4 0 0 f e e t o f s e c t i o n s u g g e s t s s e d i m e n t d i l u t i o n m a y b e a s i g n i f i c a n t f a c t o r p r o d u c i n g t h e l o w f o r a m i n i f e r a l ■ n u m b e r r e c o r d e d t h e r e . ; F o r a m i n i f e r a l n u m b e r s v a r y f r o m a g e n e r a l a v e r a g e o f ! ! 6 9 t o a p e a k o f 2 3 5 i n t h e l a m i n a t e d s h a l e u n i t o n t h e W e s t I j F o r k o f t h e S a t s o p R i v e r ( F i g . 6 5 ) . M a n y v a r i a t i o n s e x i s t ; ; i I j l o w v a l u e s a r e g e n e r a l l y a s s o c i a t e d w i t h h i g h p e r c e n t a g e s p f f a u n a I. T h i s l e n d s s u p p o r t t o t h e c o n c l u s i o n t h a t t h e i B u l i m i n e l l a e l e g a n t i s s i m a f a u n a i s p r e s e n t i n h i g h n u m b e r s i i I b e c a u s e o f d i s p l a c e m e n t . B a n d y ( 1 9 6 4 b ) h a s o b s e r v e d t h a t j i | v e r y l o w f o r a m i n i f e r a l n u m b e r s , w i t h h i g h p e r c e n t a g e s o f j i n s h o r e s p e c i e s , a r e c h a r a c t e r i s t i c o f d e e p w a t e r s a n d s j i b e l i e v e d t o h a v e b e e n e m p l a c e d b y t u r b i d i t y c u r r e n t a c t i o n | i i ! i i n S a n t a M o n i c a a n d S a n P e d r o B a s i n s , C a l i f o r n i a . ! ■ ! ! J F a u n a l D i s p l a c e m e n t j D i s p l a c e m e n t o f f o r a m i n i f e r a a l o n g w i t h t h e e n c l o s i n g I j s e d i m e n t f r o m t h e i r n o r m a l h a b i t a t i n t o d e e p e r w a t e r e n - j v i r o n s h a s b e e n r e c o g n i z e d a s a c o m m o n p h e n o m e n o n ( B a n d y , i 1 19 5 3 ; P h l e g e r , 1 9 6 0 ; B a n d y , 1 9 6 1 ) . I n m o s t i n s t a n c e s n o ) I s e r i o u s p r o b l e m i s e n c o u n t e r e d i n t h e i n t e r p r e t a t i o n o f p a l e o b a t h y m e t r y b y u s i n g t h e d e e p e s t l i v i n g f o r m s , f r o m t m i x e d f a u n a s , a s i n d i c a t o r s . H o w e v e r , t h e i d e n t i f i c a t i o n 293 | i i o f d i s p l a c e d e l e m e n t s a n d t h e a m o u n t o f d i s p l a c e m e n t c a n b e v e r y h e l p f u l f o r r e c o g n i t i o n o f s p e c i a l i z e d e n v i r o n m e n t a l i c o n d i t i o n s . j I I ! j M o r e t h a n 5 0 p e r c e n t o f t h e f a u n a i s b e l i e v e d t o b e j ! ' d i s p l a c e d i n 2 z o n e s o n t h e M i d d l e F o r k , W i s h k a h s e c t i o n j ( F i g . 6 4 ) . I n t h e u p p e r p a r t o f t h a t s e c t i o n d i s p l a c e d I I f a u n a s a r e a s s o c i a t e d w i t h a n i n c r e a s e i n g r a i n s i z e o f t h e ; ; i l . ! i s e d i m e n t . I | i A n e v e n g r e a t e r p e r c e n t a g e o f d i s p l a c e d f a u n a s w a s 1 ! j ( o b s e r v e d i n t h e l a m i n a t e d s h a l e o n t h e W e s t F o r k o f t h e ! , j ; S a t s o p R i v e r ( F i g . 6 5 ) . V a l u e s b e t w e e n 5 0 a n d 7 5 p e r c e n t j I j j a r e c o m m o n . D e p e n d i n g u p o n h o w r e s t r i c t e d t h e e n v i r o n m e n t a l i C o n d i t i o n s w e r e , i n t h e h y p o t h e t i c a l b a s i n , t h e m a j o r i t y o f ! j i (t h e f o r a m i n i f e r a m i g h t b e o f d i s p l a c e d o r i g i n . P e b b l y a n d j i i ( s a n d y m u d s t o n e f r o m t h e c h a n n e l - l i k e f e a t u r e s d e s c r i b e d I e a r l i e r c o n t a i n p r o b a b l y 1 0 0 p e r c e n t d i s p l a c e d f o r m s . I n j o n e , f o r e x a m p l e , E l p h i d i u m r u g u l o s u m ( a t y p i c a l p a r a l i c s p e c i e s ) c o m p r i s e s 9 4 p e r c e n t o f t h e f a u n a ( F i g . 6 5 ) . i I P l a n k t o n i c F o r a m i n i f e r a i | : U n f o r t u n a t e l y p l a n k t o n i c f o r a m i n i f e r a a r e g e n e r a l l y j q u i t e r a r e i n t h e M o n t e s a n o F o r m a t i o n . A s i d e f r o m t h e i r I i ( v a l u e f o r d a t i n g a n d r e g i o n a l c o r r e l a t i o n , t h e y l e n d ! . . 294 | c o n s i d e r a b l e i n s i g h t i n t o t h e t e m p e r a t u r e s o f t h e w a t e r - m a s s e s w i t h i n w h i c h t h e y l i v e d a n d a r e o t h e r w i s e s i g n i f i c a n t j i n d i c a t o r s o f p a l e o e n v i r o n m e n t a l t r e n d s . I t h a s b e e n n o t e d i i I j t h a t a l o n g t h e w e s t c o a s t o f N o r t h A m e r i c a t h e h i g h e s t p e r c e n t a g e o f p l a n k t o n i c f o r a m i n i f e r a o c c u r s i n t h e u p p e r I I b a t h y a l z o n e ( B a n d y a n d A r n a l , 1 9 6 0 ) . I n t h e s e c t i o n a l o n g I i jthe M i d d l e F o r k o f t h e W i s h k a h R i v e r c o n s i s t e n t l y m u c h l e s s J I I t h a n 1 p e r c e n t o f t h e f a u n a i s m a d e u p o f p l a n k t o n i c s p e - i c i e s . I t i s p e r h a p s n o t e w o r t h y t h a t t h e h i g h e s t v a l u e o f i : |6 p e r c e n t w a s o b s e r v e d i n W K - 3 3 , l e n d i n g s u p p o r t t o t h e i ! p r e v i o u s l y s t a t e d p a l e o b a t h y m e t r i c i n t e r p r e t a t i o n s . j i ; P l a n k t o n i c f o r a m i n i f e r a a r e p r e s e n t i n a p p r e c i a b l y ! g r e a t e r p e r c e n t a g e s i n t h e l a m i n a t e d s h a l e i n t e r v a l o n t h e ! i : ! ' W e s t F o r k , S a t s o p R i v e r . T h e r e t h e y a v e r a g e 1 0 p e r c e n t o f ; I i , i t h e f a u n a a n d r e a c h a r e l i a b l e m a x i m u m o f 2 9 p e r c e n t . A ; g r a d u a l d e c r e a s e i s e v i d e n t u p s e c t i o n . T h e l a r g e r n u m b e r ■of p l a n k t o n i c s i n t h i s s e c t i o n ( m o r e t h a n 1 0 t i m e s t h e n u m - j I j Jber i n t h e W i s h k a h s e c t i o n ) m a y r e f l e c t h i g h e r r a t e s o f i I i i p r i m a r y p r o d u c t i v i t y , p e r h a p s r e l a t e d t o u p w e l l i n g . I t i s ! J ' f u r t h e r l i k e l y t h a t t h e h i g h e r n u m b e r i s p a r t i a l l y t h e r e - i s u i t o f l e s s d i l u t i o n b y a n o r m a l l y l a r g e b e n t h i c p o p u l a - j t i o n . I n a d d i t i o n , B a n d y ( 1 9 6 4 b ) h a s n o t e d a h i g h e r p e r - j i c e n t a g e o f p l a n k t o n i c s i n t u r b i d i t e l a y e r s f r o m b a s i n s o f f J 2 9 5 j I ! s o u t h e r n C a l i f o r n i a t h a n n o r m a l b a s i n a n d s l o p e s e d i m e n t s i [ t h e r e . T h i s l e n d s s u p p o r t t o t h e w r i t e r ' s b e l i e f t h a t m o s t ! iof t h e l a m i n a t e d s e d i m e n t s o r i g i n a t e d t h r o u g h d i s p l a c e m e n t i i f r o m s h e l f a n d u p p e r s l o p e a r e a s . i I t w a s e a r l i e r s t a t e d t h a t p l a n k t o n i c f o r a m i n i f e r a a r e i j e x c e l l e n t i n d i c a t o r s o f t h e t e m p e r a t u r e o f t h e c o n t a i n i n g i w a t e r m a s s . S i n c e t h e m a j o r i t y o f t h e m l i v e b e t w e e n t h e i i ; I j s u r f a c e a n d 3 5 0 f e e t ( B r a d s h a w , 1 9 5 9 ) , s u r f a c e o r n e a r s u r - . i f a c e p a l e o t e m p e r a t u r e s c a n b e e s t i m a t e d . P l a n k t o n i c s p e c i e s ! I ' i i o b s e r v e d i n t h e M o n t e s a n o F o r m a t i o n a r e i n d i c a t i v e o f B r a d - j ' i ! i j s h a w ' s S u b a r c t i c F a u n a w i t h a f f i n i t i e s f o r h i s T r a n s i t i o n j j | F a u n a . T h e s o u t h e r n b o u n d a r y o f t h e S u b a r c t i c F a u n a i s j j c o n s i d e r e d t o c o i n c i d e w i t h t h e 1 5 d e g r e e s C e n t i g r a d e s u m m e r [ i s o t h e r m . E s s e n t i a l l y t h e s a m e a s s e m b l a g e o f p l a n k t o n i c i ! I s p e c i e s p r e s e n t l y l i v e s o f f t h e O r e g o n - W a s h i n g t o n c o a s t . [ T h e r e f o r e i t i s c o n c l u d e d t h a t s e a s u r f a c e t e m p e r a t u r e s o f f j t h e W a s h i n g t o n c o a s t w e r e o f t h e s a m e o r d e r o f m a g n i t u d e | : j d u r i n g t h e L a t e M i o c e n e a s t o d a y , b e t w e e n 1 5 a n d 1 0 d e g r e e s j ; I C e n t i g r a d e . T h i s i s c o n s i s t e n t w i t h B a n d y ' s ( 1 9 6 0 a ) c o n - | [ e l u s i o n t h a t t h e g e n e r a l t e m p e r a t u r e g r a d i e n t o f t h e P a c i f i c O c e a n h a s p r o b a b l y c h a n g e d l i t t l e s i n c e t h e E o c e n e . 296 Arenaceous Foraminifera i | F o r a m i n i f e r a w i t h a g g l u t i n a t e d w a l l s a n d s i m p l e i n t e r i o r s , s u c h a s H a p l o p h r a c r m o i d e s c o l u m b i e n s e . a r e e s s e n t i a l l y | R e s t r i c t e d t o t h e l o w e r m e m b e r o n t h e W i s h k a h R i v e r ( T a b l e 2 ). T h e r e t h e y c o m p r i s e u p t o 2 0 p e r c e n t o f t h e b e n t h i c j f a u n a . T h i s f i g u r e c o u l d b e t o o h i g h b e c a u s e o f s e l e c t i v e p r e s e r v a t i o n . A c o n s i s t e n t a v e r a g e o f 7 p e r c e n t w a s o b - j j s e r v e d i n 3 o t h e r s a m p l e s . S i m i l a r v a l u e s w e r e o b t a i n e d i n I jthe C a n y o n R i v e r s e c t i o n ( T a b l e 5 ) . B a n d y a n d A r n a l ( 1 9 6 0 ) [ h av e n o t e d t h a t t h e p r e s e n c e o f s i m p l e a r e n a c e o u s s p e c i e s j a l o n e i s n o t a g o o d i n d i c a t i o n o f t h e t y p e o f e n v i r o n m e n t . H o w e v e r , t h e s p e c i e s l i s t e d a b o v e i s a g o o d i n d i c a t o r o f i n n e r s u b l i t t o r a l a r e a s . | A r e n a c e o u s s p e c i e s w i t h c o m p l e x i n t e r i o r s t r u c t u r e s I w e r e o b s e r v e d i n o n l y 1 s a m p l e i n t h e M o n t e s a n o F o r m a t i o n . P y c l a m m i n a c a n c e l l a t a m a k e s u p 4 p e r c e n t o f t h e b e n t h i c j p o p u l a t i o n a t W K - 2 4 o n t h e M i d d l e F o r k o f t h e W i s h k a h R i v e r jThis s p e c i e s h a s l o n g b e e n r e c o g n i z e d a s a n i n d i c a t o r o f f a a t h y a l e n v i r o n m e n t s ( A k e r s , 1 9 5 4 ) ; t h e s h o a l e s t k n o w n [ r e c o r d o f i t w a s l i s t e d b y A k e r s a s 3 7 5 f e e t . P a l e o b a t h y - p i e t r y r e g i s t e r e d b y o t h e r e l e m e n t s o f t h e f a u n a i n W K - 2 4 i s i l [ c o n s i d e r e d t o b e o n t h e o r d e r o f 1 , 2 0 0 f e e t , a f i g u r e w e l l 297 i n l i n e w i t h c o n s i s t e n t o c c u r r e n c e o f C v c l a m m i n a c a n c e l l a t a a t t h a t d e p t h a n d g r e a t e r i n m o d e r n s e a s . I t i s a c u r i o u s i f a c t t h a t t h e s p e c i e s w a s n o t o b s e r v e d i n s a m p l e s o f t h e j j I j M o n t e s a n o b e l i e v e d r e p r e s e n t a t i v e o f g r e a t e r d e p t h s . M e g a - I s c o p i c e x a m i n a t i o n o f r o c k s a m p l e s f r o m W K - 2 4 r e v e a l e d t h e j c o n c e n t r a t i o n o f C y c l a m m i n a c a n c e l l a t a i n s o m e w h a t i s o l a t e d i i j p o d s . R e w o r k i n g i s u n l i k e l y i n v i e w o f t h e s t a t e o f p r e s e r v a t i o n a n d t h e l a c k o f o t h e r d e f i n i t e l y r e d e p o s i t e d e l e - : k e n t s . I t i s l i k e l y t h a t e c o l o g i c r e q u i r e m e n t s o f t h i s i i | | j s p e c i e s a r e m o r e c o m p l e x t h a n r e a l i z e d . ! M i l i a m m i n a f u s c a i s t h e o n l y a g g l u t i n a t e d s p e c i e s p r e s - l 'ent i n t h e l a m i n a t e d s h a l e o f t h e W e s t F o r k , S a t s o p R i v e r | s e c t i o n . C o n s i s t e n t l y , i t c o m p r i s e s u p t o 2 p e r c e n t o f t h e b e n t h i c p o p u l a t i o n . A s s t r e s s e d e a r l i e r , t h i s i s a I b r a c k i s h w a t e r f a c i e s i n d i c a t o r a n d i t i s t h e r e a s a r e s u l t i I o f d i s p l a c e m e n t . 1 [ P o r c e l a n e o u s F o r a m i n i f e r a j ! O d d l y e n o u g h t h e o n l y r e c o r d s a l o n g t h e M i d d l e F o r k , ^ i s h k a h R i v e r o f f o r a m i n i f e r a w i t h p o r c e l a n e o u s w a l l s a r e j f r o m 3 s a m p l e s i n t h e u p p e r m e m b e r ( T a b l e 2 ) . O u i n q u e l o c u - ' i l l i n a a k n e r i a n a b e l l a t u l a . Q. s e m i n u l a a n d P v r a o b u l l o i d e s j j m a k e u p l e s s t h a n 1 p e r c e n t o f t h e b e n t h i c a s s e m b l a g e s i n 298 t h e s e s a m p l e s . T h e l a t t e r i s p r o b a b l y i n d i g e n o u s b u t t h e 2 ; s p e c i e s o f O u i n q u e l o c u l i n a w e r e m o s t l i k e l y d i s p l a c e d f r o m i s h a l l o w i n s h o r e w a t e r s , t h e i r c h a r a c t e r i s t i c h a b i t a t i n j i i ^ m o d e r n s e a s ( B a n d y a n d A r n a l , 1 9 6 0 ) . j i j U p t o 7 p e r c e n t O u i n q u e l o c u l i n a s p p . w e r e o b s e r v e d i n i ] ‘ j t h e C a n y o n R i v e r s e c t i o n ( T a b l e 5 ) . H i g h e s t v a l u e s w e r e j a s s o c i a t e d w i t h l a r g e n u m b e r s o f E l p h i d i u m r u a u l o s u m : b o t h j j a r e t y p i c a l p a r a l i c f o r m s . ; i ; M i s c e l l a n e o u s M i c r o - o r g a n i s m s j i i ! | ! D a t a o n a v a r i e t y o f o t h e r m i c r o s c o p i c b i o g e n i c e l e - j i I I ! m e n t s h a v e b e e n r e c o r d e d f r o m s a m p l e s o f t h e M o n t e s a n o F o r - i ; j m a t i o n i n h o p e s o f i d e n t i f y i n g s i g n i f i c a n t s t r a t i g r a p h i c j i , a n d p a l e o e n v i r o n m e n t a l t r e n d s . O b s e r v a t i o n s g e n e r a l l y j i c o r r o b o r a t e i n t e r p r e t a t i o n s b a s e d u p o n f o r a m i n i f e r a l e v i - j : i d e n c e . M a j o r p o i n t s w i l l b e d i s c u s s e d b e l o w . j R a d i o l a r i a i i j S i n c e r a d i o l a r i a n s a r e p l a n k t o n i c a n i m a l s t h a t l i v e ! t h r o u g h o u t t h e w a t e r c o l u m n , t h e y h a v e p o t e n t i a l l y t h e I s a m e v a l u e f o r s o l u t i o n o f s t r a t i g r a p h i c a n d p a l e o e c o l o g i c p r o b l e m s a s d o p l a n k t o n i c f o r a m i n i f e r a . H o w e v e r , o u r e x i s t i n g k n o w l e d g e o f t h e R a d i o l a r i a i s f a r l e s s t h a n t h a t o f f o r a m i n i f e r a . T h e g r o u p i s c u r r e n t l y u n d e r s t u d y a t s e v e r a l i n s t i t u t i o n s a n d c e r t a i n u s e f u l t r e n d s a p p l i c a b l e t o p a l e o n H [to l o g i c a l p r o b l e m s h a v e b e e n e s t a b l i s h e d . ' I R a d i o l a r i a n s a s a r u l e a r e r a r e i n t h e M o n t e s a n o F o r - i ] m a t i o n . R a d i o l a r i a n n u m b e r s ( t h e n u m b e r o f r a d i o l a r i a n s I : I [per g r a m , d r y w e i g h t , o f s e d i m e n t ) a r e c o n s i s t e n t l y m u c h i ; [ l e s s t h a n 1 0 i n t h e C a n y o n R i v e r s e c t i o n , t h e l a m i n a t e d I | i [ s h a l e u n i t o n t h e W e s t F o r k o f t h e S a t s o p R i v e r a n d t h e [ l o w e r s a n d s t o n e m e m b e r o n t h e M i d d l e F o r k o f t h e W i s h k a h j i R i v e r . S u c h v a l u e s a r e c o n s i s t e n t w i t h t h e f i n d i n g s o f : i : I B a n d y a n d A r n a l ( 1 9 5 7 ) a n d B a n d y ( 1 9 6 1 ) f o r s h e l f a r e a s o f f I j t h e w e s t c o a s t o f C e n t r a l A m e r i c a a n d i n t h e G u l f o f C a l i - ! 1 f o r n i a , r e s p e c t i v e l y . j ! ! T h e r e i s a g r a d u a l i n c r e a s e o f r a d i o l a r i a n s t h r o u g h t h e S l o w e r p a r t o f t h e u p p e r m e m b e r o n t h e W i s h k a h t o a m a x i m u m i ‘ r a d i o l a r i a n n u m b e r o f 1 5 4 a n d t h e n a g r a d u a l d e c l i n e t o t h e j t o p o f t h e f o r m a t i o n ( F i g . 6 4 ) . T h e p e a k i n a b u n d a n c e g e n e r a l l y c o i n c i d e s w i t h t h a t f o r f o r a m i n i f e r a ; h o w e v e r , t h e j i j ; r a t i o o f r a d i o l a r i a n s t o f o r a m i n i f e r a i s c o n s i s t e n t l y m u c h j i [ l e s s t h a n 1. T h e f e w c a s e s w h e r e i t e x c e e d s t h i s v a l u e c a n jbe e x p l a i n e d b y t h e f a c t t h a t c a l c a r e o u s f o r a m i n i f e r a w e r e ! ' l a r g e l y l e a c h e d o u t o f t h e r o c k . I t h a s b e e n o b s e r v e d t h a t j I i r a d i o l a r i a n s e x c e e d f o r a m i n i f e r a i n a b u n d a n c e b e l o w a b o u t i I_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ — - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 300 ! I I 5 , 0 0 0 f e e t o f f t h e w e s t c o a s t o f N o r t h A m e r i c a ( B a n d y a n d A r n a l , 1 9 5 7 ; B a n d y , 1 9 6 1 ) . T h e r e f o r e , i t i s p r o b a b l e t h a t J n o n e o f t h e k n o w n s t r a t a o f t h e M o n t e s a n o F o r m a t i o n w e r e ! i i ! ' d e p o s i t e d b e l o w t h a t d e p t h . T h e h i g h e s t r e c o r d e d v a l u e s o f j |l54, 1 3 9 a n d 1 2 8 ( T a b l e 2 ) i m p l y t h a t d e p o s i t i o n t o o k p l a c e ' i n t h e u p p e r t o m i d d l e b a t h y a l r e g i o n s o f t h e s e a . T r e n d s i n m o d e r n r a d i o l a r i a n d i s t r i b u t i o n r e c o r d a c o n t i n u o u s i n - j c r e a s e i n t o d e e p e r w a t e r . T h e d e c r e a s e i n t o i n f e r r e d d e e p e r I ■ w a t e r d e p o s i t s i n t h e M o n t e s a n o ( F i g . 6 4 ) i s a t t r i b u t e d t o | d i l u t i o n b y d i s p l a c e d s e d i m e n t . j i I : j S t a t o l i t h s A v a r i e t y o f o r g a n i s m s , b o t h a q u a t i c a n d t e r r e s t r i a l , j ! j p o s s e s s s o m e f o r m o f s t a t o c y s t u s e d a s a b a l a n c i n g o r g a n . i i I T h e s e s a c k - l i k e s t r u c t u r e s o f t e n c o n t a i n s e c r e t e d p e l l e t s ! o f v a r i a b l e c o m p o s i t i o n , s h a p e , a n d s t r u c t u r e c o l l e c t i v e l y ! ; I t e r m e d s t a t o l i t h s . M a n y a r e p r e s e r v a b l e a n d a r e t h e r e f o r e j p o t e n t i a l a i d s i n t h e s o l u t i o n o f s t r a t i g r a p h i c a n d e c o - i j l o g i c p r o b l e m s . i j B a n d y a n d K o l p a c k ( 1 9 6 3 ) h a v e r e p o r t e d a n d f i g u r e d i I s t a t o l i t h s f r o m M o h n i a n s t r a t a o f t h e M o n t e r e y F o r m a t i o n i n s o u t h e r n C a l i f o r n i a . T h e s e a u t h o r s r e f e r r e d t h e s t a t o l i t h s t o m y s i d s . A l t h o u g h a m o u n t i n g t o o n l y a f e w s p e c i m e n s p e r g r a m , t h e y w e r e n o t e d o n l y f r o m b e d s e s t i m a t e d t o h a v e b e e n j d e p o s i t e d i n 5 , 0 0 0 t o m o r e t h a n 6 , 5 0 0 f e e t o f w a t e r . j i ! S t a t o l i t h s v e r y s i m i l a r t o t h e t y p e f i g u r e d b y B a n d y i i j a n d K o l p a c k w e r e o b s e r v e d t h r o u g h o u t t h e M o n t e s a n o F o r m a t i o n , b u t g e n e r a l l y i n v e r y l o w n u m b e r s ; a v e r a g i n g c o n s i d e r a b l y l e s s t h a n 2 p e r g r a m . A g r a d u a l , a l t h o u g h q u i t e v a r i a b l e , i n c r e a s e w a s n o t e d u p s e c t i o n a l o n g t h e M i d d l e 1 i F o r k , W i s h k a h R i v e r t o a m a x i m u m r e c o r d e d v a l u e o f 9 p e r g r a m i n s a m p l e W K - 3 9 . T h i s p o r t i o n o f t h e c o l u m n i s c o n - I I | s i d e r e d r e p r e s e n t a t i v e o f t h e d e e p e s t b a t h y m e t r i c z o n e i n jt h e f o r m a t i o n . O n e m i g h t t h e n u s e r e v e r s e r e a s o n i n g a n d i I c o n c l u d e t h a t s t a t o l i t h s i n c r e a s e i n n u m b e r i n t o d e e p - w a t e r s e d i m e n t s . H o w e v e r , E n b y s k ( 1 9 6 0 ) r e p o r t e d m y s i d s t a t o - I ! j l i t h s f r o m o n l y s h e l f d e p o s i t s i n a r e c o n n a i s s a n c e s t u d y o f I I t h e n o r t h e a s t P a c i f i c . W o r k i n p r o g r e s s i n d i c a t e s a g o o d p o s s i b i l i t y t h a t t h e s t a t o l i t h s o f B a n d y a n d K o l p a c k a n d t h i s w r i t e r a r e n o t t h e s a m e a s t h o s e o f E n b y s k ( C a r l s o n l a n d R u n g e , 1 9 6 4 ) . C a r l s o n a n d R u n g e h a v e n o t e d s e v e r a l I d i f f e r e n t t y p e s o f s t a t o l i t h s p r e s e n t o n t h e c o n t i n e n t a l ! j s h e l f a n d s l o p e o f f O r e g o n . A m a x i m u m s t a t o l i t h n u m b e r o f ! 1 2 p e r g r a m w a s r e c o r d e d i n s e d i m e n t s f r o m 4 0 0 f e e t a n d i I 11 , 8 0 0 f e e t o f w a t e r r e s p e c t i v e l y . I n t e r v e n i n g v a l u e s I | j r a n g e d f r o m 2 t o 6 . A s h a r p d e c l i n e t o a n a v e r a g e n u m b e r - ~ . . . - - ! 3 0 2 | I o f 1 w a s n o t e d i n d e p t h s d o w n t o 6 , 5 0 0 f e e t . I t i s o b v i o u s ! t h a t t h e e c o l o g i c s i g n i f i c a n c e o f s t a t o l i t h s i s t o o p o o r l y i u n d e r s t o o d t o y e t b e o f m u c h v a l u e . O f c o u r s e , t h e r e i s | ^ a l w a y s t h e p o s s i b i l i t y t h a t t h e l a r g e n u m b e r s o f s t a t o l i t h s ! ; n e a r t h e t o p o f t h e M o n t e s a n o m a y b e t h e r e s u l t o f d i s p l a c e - ! | i j m e n t f r o m s h o a l e r e n v i r o n m e n t s . j i |Di a t o m s J I ! ! i j i A p r o g r e s s i v e i n c r e a s e i n t h e i m p o r t a n c e o f d i a t o m r e - ' i ! ! i j m a i n s a l o n g w i t h r a d i o l a r i a n s i n t o d e e p e r w a t e r a r e a s h a s j i | ; b e e n n o t e d i n a n u m b e r o f s t u d i e s o f m o d e r n e n v i r o n m e n t s ! I ; I ; I a l o n g t h e w e s t c o a s t o f N o r t h A m e r i c a ( B a n d y , 1 9 6 3 ; B a n d y ; ' ! a n d A r n a l , 1 9 5 7 ) . O v e r w h e l m i n g n u m b e r s o f d i a t o m s a s s o c i - j ! i l a t e d w i t h t h e r e d u c t i o n a n d i m p o v e r i s h m e n t o r e x c l u s i o n o f I ( i i b e n t h i c f a u n a s a r e c h a r a c t e r i s t i c o f d e e p , r e s t r i c t e d b a s i n j b o t t o m s ( B a n d y , 1 9 6 1 ) . j D i a t o m f r u s t u l e s w e r e n o t e d i n m o s t s a m p l e s o f t h e M o n t e s a n o F o r m a t i o n , a l t h o u g h g e n e r a l l y i n r a t h e r l o w n u m - j ; b e r s ( T a b l e s 2 , 3, 4 a n d 5) . D i a t o m n u m b e r s ( t h e n u m b e r o f j I i f r u s t u l e s p e r g r a m , d r y w e i g h t , o f s e d i m e n t ) a r e a l l l e s s | j t h a n 1 0 i n t h e l o w e r m e m b e r o n t h e M i d d l e F o r k , W i s h k a h R i v e r ( F i g . 6 4 ) . T h i s i s f o l l o w e d b y a r a p i d r i s e t o m o r e t h a n 5 0 0 p e r g r a m i n s a m p l e W K - 3 0 a n d t h e n a n e q u a l l y r a p i d 303 d e c l i n e t o a n a v e r a g e o f a r o u n d 1 5 i n t h e u p p e r p a r t o f t h e f o r m a t i o n . T h e c u r v e f o l l o w s v e r y c l o s e l y t h o s e f o r f o r a m - | 1 ^ i n i f e r a l n u m b e r a n d r a d i o l a r i a n n u m b e r . i I j B a n d y ( 1 9 6 1 ) h a s s t a t e d t h e f o l l o w i n g w i t h r e s p e c t t o j d i a t o m s i n t h e G u l f o f C a l i f o r n i a s e d i m e n t s : " D i a t o m s a l s o ; i : i a t t a i n d o m i n a n c e i n s h a l l o w e r b a t h y a l w a t e r s i n m a n y p l a c e s , i j | ^ e s p e c i a l l y j u s t b e l o w t h e e d g e o f t h e s h e l f . " A l t h o u g h i : I ! j d i a t o m b l o o m s o c c u r p r i m a r i l y i n s h a l l o w w a t e r , B y r n e a n d E m e r y ( 1 9 6 0 ) c o n c l u d e t h a t t h e y a r e d e p o s i t e d f o r t h e m o s t ; I ! | ; j p a r t i n d e e p e r a r e a s o f t h e G u l f . P a l e o b a t h y m e t r i c i n t e r - j ; i p r e t a t i o n s f o r t h e M o n t e s a n o F o r m a t i o n a r e c o n s i s t e n t w i t h j I i I I I | t h e s e f i n d i n g s . j i D i a t o m n u m b e r s i n t h e l a m i n a t e d s h a l e o n t h e W e s t F o r k , j i I ! I i S a t s o p R i v e r v a r y g r e a t l y w i t h a n a v e r a g e a r o u n d 3 0 a n d a j I I I j i m a x i m u m o f 1 7 4 ( F i g . 6 5 ) . H i g h e s t c o n c e n t r a t i o n o f d i a t o m i : i ; f r u s t u l e s c o i n c i d e s w i t h t h e l a r g e s t p e r c e n t a g e s o f p a l e o - j , I b a t h y m e t r i c f a u n a I I I a n d i n t h i s r e s p e c t i s s i m i l a r t o t h e i ! d i s t r i b u t i o n a l p a t t e r n o n t h e W i s h k a h . i I b s t r a c o d e s i i | O s t r a c o d e c a r a p a c e s a r e e x t r e m e l y r a r e i n M o n t e s a n o I s e d i m e n t s . T h e o c c u r r e n c e s a r e a s s o c i a t e d w i t h i n n e r s u b - j l i t t o r a l d e p o s i t s o r d i s p l a c e d s e d i m e n t . O s t r a c o d e n u m b e r s jare w i t h o n e e x c e p t i o n m u c h l e s s t h a n 1; a v a l u e o f 3 p e r I j g r a m w a s r e c o r d e d f r o m s a m p l e W W K - 1 4 o n t h e W e s t F o r k o f t h e I t W i s h k a h R i v e r . I n a l l c a s e s t h e r a t i o o f f o r a m i n i f e r a t o ! ( | i o s t r a c o d e s i s g r e a t e r t h a n 1 0 0 a n d u s u a l l y m u c h g r e a t e r . A ! I j i ( g e n e r a l d e c r e a s e i n t h e n u m b e r o f o s t r a c o d e s w a s n o t e d j I | [ g o i n g u p s e c t i o n a l o n g t h e M i d d l e F o r k , W i s h k a h R i v e r . ; B a n d y ( 1 9 6 3 ) h a s o b s e r v e d t h a t f o r a m i n i f e r a l / o s t r a c o d e i j j v a l u e s o f l e s s t h a n 1 0 0 a r e p r e s e n t o n l y i n l a g o o n s a n d [ e s t u a r i e s a n d i n n o c a s e d i d h e f i n d o s t r a c o d e s i n e x c e s s I i ; i Jof f o r a m i n i f e r a . T h e g r e a t r a r i t y o f o s t r a c o d e s i n t h e i ; M o n t e s a n o F o r m a t i o n i s c o n s i s t e n t w i t h s i m i l a r l y v e r y l o w | i n u m b e r s i n m o d e r n s u b l i t t o r a l a n d d e e p e r w a t e r e n v i r o n m e n t s . j M o l l u s c s i | i T h e M o n t e s a n o F o r m a t i o n c o n t a i n s a n a b u n d a n t , w e l l - ; j i I ( p r e s e r v e d , a n d v a r i e d m o l l u s c a n f a u n a i n a d d i t i o n t o s e v e r a l o t h e r i n v e r t e b r a t e g r o u p s . W e a v e r a t v a r i o u s t i m e s r e p o r t e d ( f r o m 3 0 t o 7 0 s p e c i e s o f m o l l u s c s f r o m t h e f o r m a t i o n . B a s e d . | i u p o n a p r e l i m i n a r y e x a m i n a t i o n t h e w r i t e r b e l i e v e s t h e r e t o i i jbe i n t h e n e i g h b o r h o o d o f 1 0 0 o r m o r e s p e c i e s p r e s e n t . A | t h o r o u g h e x a m i n a t i o n o f t h e m i s d e s i r a b l e a n d w o u l d b e a d e f i n i t e c o n t r i b u t i o n t o a p r o p e r u n d e r s t a n d i n g o f t h e r e l a t i o n s h i p b e t w e e n f o r a m i n i f e r a l a n d m o l l u s c a n s u c c e s s i o n s I 305 I t I I iin the Tertiary strata of the Northwest and the entire West I I iCoast. To accomplish this an intensive biometric study of | llarge numbers of individuals from many areas would be neces-J jsary. Such a treatment is beyond the scope of this paper; j 'however, certain valuable observations pertaining to the ! i | paleoecology of the formation can be stated. Notes will j i ! be confined principally to those strata where foraminiferal j ’ I i jevidence is lacking or insufficient. Specific identifies- : itions are tentative pending a more thorough study. Ecologid ! | idata have been taken largely from Clark (in Natland, 1957), j i i ; i ;Bandy (1958), and Keen (1963). j 1 j i As mentioned several times previously in this paper, | the contact between the Montesano and underlying formations lis frequently marked by abundant borings. A wide variety of marine organisms, including species of pelecypods, gas tropods, chitons, echinoids and worms, are responsible for such features (see Emery, 1960). Principal among the bor ings beneath the Montesano Formation are those made by several species of pelecypods. Aside from filled borings, many well-defined external and internal molds of the organ isms were observed and in a few cases poorly to well pre served shells were present. A notable example is at the exposure of the basal contact on the Canyon River (Fig. 33). 306 At that locality abundant specimens of Penitella penita and Platyodon colobus were collected. The former is a common west coast species ranging from the littoral zone to possi- i j i jbly as deep as 270 feet but with maximum occurrence at and 'just below low, low water. Living species of Platyodon are i j : Iconsidered entirely intertidal organisms. Another rock j jboring clam, Adula falcata. was observed to be dominant at j | i jthe basal contact on the Wynoochee River and at 2 places on j . i |the Middle Fork of the Satsop River. Keen ( 1 9 6 3 ) lists the j I i Jgenus as ranging from intertidal areas to a depth of about j i i I 65 feet. The largest borings, up to 15 inches long, were j made by Zirfaea (?) sp. Fragmented molds of this form were observed on the Middle Forks of the Wishkah and Satsop j j j i jRivers. The animal probably reached a length of at least 4 I jinches. This genus is considered an intertidal form in modern seas. This assemblage of intertidal boring pelecy- j pods confirms the conclusion that initial deposition of the I Montesano Formation took place in the littoral zone. A Spisula-Chione paleobathymetric faunal assemblage i jrepresenting a maximum range in water depth of 0 to 165 feet j jand a generally clean sand substrate is characteristic of I !the basal sandstone units of the Montesano throughout the area studied. Although these 2 genera range as deep as listed above, most reports of species are from lagoons and J particularly sandy beaches out to just beyond the surf zone.: '.Dominant elements of the assemblage in the Montesano Forma- i | I ■ ! jtion are Spisula spp. (including Spisula albaria). Chione I j isecuris. C.. ensifera. and Polinices spp. The species Crepi- dula princeps. Anadara devincta. A. trilineata. Katherinellc( anoustifrons are also prominent. j i The assemblage is excellently represented in the lower ' i 1700 feet of the upper West Fork, Satsop River section and ' I : i j jthe bottom 450 to 500 feet on the Canyon River. It is rep- j ! ; resented partially in the upper Middle Fork, Satsop River j 'section and there represents the deepest zone encountered, j i The foraminiferal, sandy mudstone of the Canyon River and | 1 i IWest Fork Satsop sections follows the Spisula-Chione bearing I ■strata with a fauna characterized by Cvclocardia subtenta. j Acila conradi, Solen sp., Thracia trapezoides and associated forms. These species represent environments in line with foraminiferal paleobathymetry outlined earlier. This unit i lis followed by massive sandstone containing abundant Spisulc. |sp. indicating a return to innermost sublittoral depths. | ; The Spisula-Chione assemblage is also well developed }in the basal part of the Montesano in the northern Wishkah [ jarea particularly on the West Fork, Wishkah River. In this 3 08 i jarea the fauna is followed by strata containing abundant and! ! jdiagnostic foraminifera that delimit a gradually increasing ; i t ■paleobathymetry. An associated abundant and varied mega- 1 i I jfauna suggests paleoenvironments in agreement with the foraminiferal evidence, as far as can be determined. i j It is noteworthy that megafossils are extremely rare | I I iin the laminated shale on the West Fork, Satsop River sug- j I | | jgesting adverse environmental conditions, complementing the ; I (foraminiferal data. Molluscs observed were for the most | | I Ipart either definitely displaced shelf species or thin | ; ! ishelled species of Macoma. The latter were found only in j I I i the occasional unlaminated portions of the unit. . i Two obvious zoogeographic changes are displayed between) i jthe Montesano faunas and modern assemblages. Keen (1963) i j (has stated that Anadara and Chione are represented in modern 1 j seas only south of Point Conception, California. Similar differences were previously noted in the microfauna. l i j Terrestrial Flora { A small flora was collected along the Canyon River (which reflects terrestrial climatic conditions somewhat I jdifferent from that presently found in the area. Specimens i 1 (are too fragmentary to allow specific identifications; 3 09 however, D. I. Axelrod (personal Communication) believes that species of the following are present. j Persea (avocado) I | Liquidambar (sweet gum) | Betula (birch) j Carya (hickory) I I Ouercus (oak) | Sassafras (sassafras) i I |He concluded from this that the climate was mild temperate jwith only moderate ranges of seasonal temperature and per- j ! ; haps as much as 50-60 inches of yearly precipitation well j i distributed through the seasons. This is in contrast to j i ! more than 80 inches annually at the present (Rudd, R. D. in j ! I jHighsmith, 1962) . i Even though rigorous textural and compositional analy- i | ;ses were not made of the sedimentary rocks of the Montesano Formation, it is possible to arrive at a number of general the most significant aspects will be treated at this time, j The basal portion of the formation is universally made sandstone. Rounded pebble-size clasts are frequently either disseminated or in discontinuous beds. The conglomerate Environmental Aspects of the Sediment inferences regarding the environment of deposition. Only rather well sorted, fine-grained beds often contain high numbers of mollusc shells and abun- j dant carbonaceous debris. It was noted that mollusc shells,; I ! i ! randomly distributed through the sediment, are frequently j jwhole, suggesting they were preserved in life position. On I I J i |the other hand, those in the conglomerate are generally i ; [disarticulated, fragmental and abraded, suggesting accumu- I i lation under high energy conditions such as surf action. i i . ! jThese features are particularly well developed at the immed-'; iiate base of the formation where it rests upon the under- i i jlying rock. Many examples have been described in detail in earlier portions of this report. i i ( ! : The lithologic characteristics of the lowermost sand j i 'units just described are very similar to those of modern j i ! beach and inner sublittoral sediments being deposited off 1 Isouthern California (Emery, 1960) and probably in many other i areas. Thus, characteristics of the sediment point toward the same paleoenvironmental interpretation as drawn from | ! ! :the molluscan assemblage present. In most of the sections examined the lower sand gradu ally contains higher percentages of silt and clay upsec- ition; eventually resulting in sandy mudstone as, for in- [ i [stance, in the Canyon River and upper West Fork, Satsop iRiver sections. Such a trend is typically encountered as one moves offshore across the continental shelf into deeper ; i |water areas. The faunas from these mudstone units also ; ^indicate deeper water conditions. ! ' ! | Several fluctuations, in the trend toward over-all j ; 1 decrease in average grain size upsection in the lower mem- 1 jber, are encountered in the traverses of the northern Wish- 1 jkah area. These could easily record changes in the rate ofj I ! i i jsediment influx. i In the northern Wishkah area the reduction in grain ! ! isize continues through the formation into the mudstone and j ! j siltstone of the upper member. This sediment type is con- i j : i I sistent with the interpretation of upper to middle bathyal j i environments based upon faunal elements. A reversal to | j siltstone and silty, very fine-grained sandstone at the top j iof the section is considered to be the result of displace ment of shelf deposits into deeper water. I ; I One of the most interesting types of lithology encoun tered during this study is the laminated shale unit on the I i j jWest Fork of the Satsop River. It has been pointed out ! jthat extensively developed laminations such as those encoun tered in this part of the Montesano Formation most likely | jaccumulated in an area devoid of significant numbers of i I jburrowing organisms (Hiilsemann and Emery, 1961). Otherwise, 312 | activity of the animals would destroy the laminations. It has already been noted that megafossils are rare in the 'section at this point. A lack of benthic organisms can be equated to abnormally low oxygen values in restricted basinsi I |such as in Santa Barbara Basin off southern California 1 |(Hiilsemann and Emery, 1961) . The nature of the foramini- Sferal fauna in the laminated shale has already been pointed I j jout as indicative of low oxygenated conditions. Hulsemann and Emery noted that relatively barren lami- j inated zones alternated with homogeneous sediment containing ! I i i I abundant evidence of animal activity in cores from Santa j [Barbara Basin. They concluded that the homogeneous zones Recorded periodic return of well oxygenated conditions to the basin. Similarly homogeneous intervals up to 2 feet thick were observed in the laminated unit of the Montesano. j As previously noted, the homogeneous zones contain the highest numbers of megafossils. Laminations in the Montesano Formation are composed, for the most part, of graded layers of very fine-grained sandstone, siltstone, and claystone. More than this, there lis an alternation of dark and light colored layers. The | latter are the thinnest and composed of white to light gray very finely divided ash and bentonitic clay. Volcanic 313 ; ! glass shards are common to abundant through most of the unit with the largest fragments present, generally, in the coar- I ;ser-grained layers. It is suggested that the dark layers | i j i i jare composed of one or more essentially instantaneously i i emplaced turbidite deposits and that the light colored bands! ! [represent times of very slow deposition of fine ash which j : jwas slowly settling through the water column at all times. [ i ! |As previously pointed out, foraminifera are concentrated in ; jthe thin, light colored layers corroborating the low rate i ! : i [of sediment accumulation. | ; i ; Rather uniform spacing of couplets of dark and light j | | ilaminated zones is suggestive of seasonal cycles of deposi- ! | tion. The dark turbidite layers were possibly formed during I j periods of high rainfall and runoff (winter and spring) and [the light layers during times of no rainfall and low runoff ! I (summer and fall) . If these, in fact, are varved sediments,j i it would be possible to determine how long it took for the ! I [ entire laminated unit to be deposited. Necessary field [measurements to accomplish such a determination were not i {made; however, it is possible to estimate an order of mag- i [nitude. The minimum average thickness of couplets through Lnuch of the section is about 0.4 inches. It is greater near ithe base and toward the top. The absolute thickness of the I ______________________________________ ______________________________________ unit is uncertain but estimates range from 1,000 to 1,600 ; feet. Using a figure of 0.4 inches per year, periods of j { 130,000 to 48,000 years are obtained. A greater average ! | ! thickness for couplets would produce lower figures. Much i jadditional study is needed before the validity of these | i ; |figures can be ascertained. ; ! Zones up to 5 feet thick displaying convolute struc- j I | jtures bounded, top and bottom, by undisturbed zones indicate I 1 I jmass movement by slumping from the sides of the basin. Such! jslumping was prominent locally. ; j Of particular note, in the laminated shale sequence of j i i the Montesano Formation, are the channel and apron-like j i j deposits of poorly sorted, coarse-grained elastics in its j | j upper part. A filled channel is well exposed at MWS-33. j As discussed earlier, the dominant sediment in this channel . I is a pebbly and sandy mudstone containing eroded fragments j : i of large pelecypod shells and displaying convolute struc- j itures. The pelecypod shells and foraminifera are character istic of brackish and innermost sublittoral environments. i [Essentially identical deposits have been recorded and illus- ! jtrated by Gorsline and Emery (1959) from submarine canyons and the upper parts of subsea fans in southern California |offshore basins . 315 | | It is of interest to note the concentration of muriforiq I i (masses of pyrite in the thin, light colored laminae of the i ; (laminated shale unit. Such accumulations have been noted ! [by Emery (1960) to be common in subsill basin sediments of isouthern California. i | ! There is a gradual increase in the average grain size upsection in the upper part of the laminated shale unit. Sandstone beds increase in number and thickness; and the I iunit grades into sandstone with thin, discontinuous pebble (beds and megafossils indicative of shelf environments. The upper 400 to 800 feet of section in the northern I ISatsop area is devoid of definitely marine fossils but con- ; Itains large amounts of carbonized wood. The average grain ; isize of these sediments is greater than in most other parts | I of the Montesano Formation, and conglomerate beds are more ( frequent. The bases of the latter are channeled into under lying sandstone and the beds have flat tops. Gentle cross- ; I bedding is common. All these factors suggest that the I | j previously-mentioned basin had filled and that final sedi- j j mentation had possibly taken place on extensive sand flats j [at, or perhaps above, sea level. j ! There is a general trend toward an increase in over-allj I | (average grain size and in the percentage of conglomerate in 316 I the Montesano Formation toward the east in Grays Harbor Basin. i : i ; i Summary and Conclusions i I I Eight paleoenvironmental faunal assemblages have been i | I jrecognized in the Montesano Formation. A brackish faunal ; {assemblage is characterized by Miliammina fusca and Elphi- j I ; jdium ruaulosum and considered indicative of brackish estu- | j ! jarine, lagoonal and innermost sublittoral areas. Its pres- ' i j jence in the Montesano strata observed is due largely to | I i [displacement; however, a probable in situ relationship j j 1 [exists in the lower part of the Canyon River section. ! i I A second assemblage is made up of several rock boring ! I 'pelecypods. These mark the basal contact in many places I ! i j | land indicate intertidal to immediately subtidal environ- I j ments. They are Penitella penita. Platyodon colobus. Adula ! : j falcata and Zirfaea (?) sp. i | A molluscan fauna, the third assemblage, characterized i jby several species of Spisula and Chione. is universally j [present in the sandstone of the basal few hundred feet of ] I i i the formation. The total depth range of this group is 0 to ;15 0 feet; however, it is found in abundance generally in I i jand just seaward of the surf zone along exposed coasts with ja sandy substrate. i . ; j The sections of the northern Wishkah area and along | Ithe middle portion of the West Fork, Satsop River contain | i l jabundant foraminifera that can be used effectively to de limit paleoenvironments. Four foraminiferal assemblages | jare present. Inner and outer sublittoral and upper and ) ; middle Bathyal benthic environmental zones are represented I i i ! jby a Buliminella elecrantissima Fauna (0-150 feet, 10 to 15 jdegrees Centigrade), a Nonionella Fauna (150-650 feet, 7 to ! i j 1 10 degrees Centigrade), a Bolivina Fauna (6 50-2,000 feet, :5 to 7 degrees Centigrade), and a Uvigerina perearina his- j I | jpidocostata Fauna (2,000-8,000 feet, 2 to 5 degrees Centi- ! ; # ! grade) respectively. The successive occurrence of these | ! ! faunas upsection in the northern Wishkah area indicates a ; iprogressive increase in water depth from 0 to at least I 3,500 feet during the deposition of the Montesano Formation.! The impoverished appearance of the eighth foraminiferal. i assemblage and the presence of Bolivina seminuda along with ! jlaminated characteristics of the sediment indicate that i jportions of the Montesano Formation accumulated in a re- i j jstricted basin. This resulted in the thick sequence of !laminated shale and associated sediments along the middle | (portion of the West Fork, Satsop River. Dominant benthrc 318 I I foraminifera suggest a sill depth of 650 to 1,000 feet; a | i basin plain depth of 1,500 feet or more is indicated by j I plankton. The laminated character of the sediment, rarity r !of megafossils, and the impoverished foraminifera attest to j ! i i I a deficiency of oxygen within the basin. j ; i I Most sedimentation took place in the basin through j |turbidity current activity and slumping. This is indicated j I I jby graded bedding, convolute structure, large numbers of \ ] | !displaced foraminifera, and channel fillings of unsorted, ! I , ooarse-grained elastics of shallow water origin. > i Trends in the number of species of foraminifera, for- | I ! jaminiferal number, and distribution of planktonic, arena- ! i i jceous and porcelaneous groups further corroborate the paleo-j j bathymetry determined for the Montesano Formation. Various ; I I ! j other microfossils and miscellaneous sediment trends also ; i substantiate the interpretations based upon foraminifera. ] i Large numbers of displaced foraminifera were recognizecj in the uppermost part of the formation in the northern i fWishkah area and in the laminated shale unit on the West I i iFork of the Satsop River. | i A planktonic fauna composed of 8 species is similar to I jthat characterizing Bradshaw's Subarctic Fauna. Some affi- jnities are evident for his Transition Fauna. In general, the same kinds of species presently live in the water column) !off the Pacific Northwest. Therefore paleo-surface tempera-; | i jtures of 10 to 15 degrees Centigrade are postulated for LateJ Miocene seas in this area. j I | A meager terrestrial flora collected from the Montesand suggests that a mild temperate climate prevailed over bor- ! dering land areas during its formation. Only moderate j ! j ranges of seasonal temperature and perhaps 50-6 0 inches of , annual precipitation, well distributed through the seasons, ! I i jare indicated. By comparison, the present average annual j I j precipitation for Grays Harbor Basin exceeds 80 inches j (Rudd, R. D., in Highsmith, 1962). CONCLUSIONS ! ] i The Montesano Formation, as mapped, covers about 250 j | j ■square miles in Grays Harbor Basin, Washington. It probably i | extends farther to the west but is there covered by later ! ! i deposits. | j Two sets of folds, oriented east-west and north-south | I ^respectively, have been developed in the Montesano. The j | ! Ifirst of these probably reflects major basement structural j i | control which maintained Grays Harbor Basin as a significant] j depositional basin throughout most of the Tertiary. The j ; I i i jnorth-south set is considered to have resulted from Casca- j ; ! jdian orogenic activity which followed, in general, pre- 1 Montesano structural trends. Faults are not as clearly de- j limited as folds but generally follow northwest-southeast ; | land northeast-southwest oriented patterns. The former di rection is the most prominent and may indicate a relation- i : jship to similar trends along the north side of the Olympic fountains. | i A distinct erosional unconformity separates the Monte- sano from older units wherever the contact was observed. | In the Wishkah area the formation averages 2,500 feet ;in thickness and is divided into 2 members. The lower one ' [ ! , I jis about 1,500 feet thick and composed principally of fine grained sandstone (subfeldspathic lithic arenite) with j 'pebble conglomerate and mudstone locally dominant. One thousand feet of tuffaceous mudstone and sandy siltstone j I ' ! 1 (characterize the upper member. To the east the Montesano i | laverages 1,800 feet in thickness and is made up predominant-) I i ' t I |ly of conglomeratic, fine- to medium-grained sandstone. On j the West Fork of the Satsop River, an abnormal section of i j [ Ithin-bedded to laminated mudstone and very fine-grained I I (sandstone about 1,100 feet thick contributes to perhaps a j S S (maximum thickness of more than 3,000 feet. Since the top I i jof the formation was not observed during this study, the formation might be thicker to the west where it is covered by more recent deposits. ! ! It is concluded that the section exposed along the Middle Fork of the Wishkah River should be the type section of the Montesano Formation since one had not been designated i ! Over most of the area studied there is no difficulty ! jin differentiating lithologically between the Montesano and 322 Astoria Formations. This is because the former always has j a sandstone unit at its base and the latter is most often a j j mudstone, in that area. However, sandstone of the Montesanoj jrests, in some places, on similar sandstone of the Astoria. I i 'Where this situation was encountered during the present 1 j | jstudy, the contact between these 2 formations, unfortunate- | i : ly, was concealed. In such cases a prominent zone of con- j i jglomerate was used to approximate the lower limit of the ; j i |Montesano Formation. j ! ■ I i This paper contains the first account of foraminifera j ! I I from the Montesano Formation. It contains a well preserved i | j ifauna containing more than 100 species and subspecies. ;Eighty-four of them have been identified. No diagnostic i I 'index species of previously established California zones I |were found in the lower member in the Wishkah area. How ever, the presence of Hanzawaia illinai and stratigraphic position suggest a correlation with the late Mohnian foram- 'iniferal age of the California Late Miocene. The Bolivina I I jobliqua Zone of the lower portion of the superjacent Del- j jmontian and the Rotorbinella (?) aarveyensis Zone of the I jupper Delmontian are recognized in the upper member. The i Montesano is therefore Upper Miocene. Insufficient forami- i I i Iniferal evidence is present to indicate whether any portion of it reaches into the Lower Pliocene. | ! I Few species of foraminifera are common to both the j Montesano and Astoria Formations. The latter is referred to j i jthe Saucesian and possibly Relizian of California (Lower 1 i jand Middle Miocene) on the basis of benthic faunas. There- ■ |fore, as far as can be determined from this study, most of j the Relizian, the Luisian, and much of the Mohnian (Middle ! j ! | jand Late Miocene) record is missing from the area studied. ! The Quinault Formation is considered to be Early to ' i | jMiddle Pliocene in age on the basis of planktonic forami- j i i inifera and therefore younger than the Montesano Formation. ! i > 1 . . 1 The Montesano was deposited m a sea transgressing | :west to east over the land. In the Wishkah area water 1 ■depth increased progressively from the littoral zone to I jmore than 3,000 feet. This is indicated by the successive ! j | ■appearance of 8 paleobathymetric faunas and trends in other | i jpaleoecologic parameters. To the east water depths gener ally did not exceed about 600 feet. The upper half of the i iformation in that area reflects a regression of the sea not i ! jrecognized to the west. The laminated mudstone contains I | Iforaminifera and sediment which suggest deposition in a Iclosed basin. i i ! Planktonic foraminifera indicate that sea surface I _________________________________________________________________ - 324 | s temperatures were approximately 10 to 15 degrees Centigrade j during the deposition of the Montesano. The terrestrial j jflora reflects a mild temperate climate. 1 F A U N A L RE FE R E N C E LISTS i FAUNAL REFERENCE LISTS ! Listed below are the references to the original de scriptions and figures of each species of foraminifera and imollusc discussed in the foregoing text. Trinomials repre sent genus, species, and subspecies. The preferred modern (name is followed by the original designation for ease of ilocation in the Catalogue of Foraminifera (Ellis and Mes- jsina, 1940-1965). Lincoln Formation For amini fer a Anomalina californiensis Cushman and Hobson, 1935, Contr. Cushman Lab. Foram. Res., v. 11, pt. 3, p. 64, pi. 9, fig. 8. S Bulimina inflata alliaata Cushman and Laiming, 1931, Jour, ! Paleontology, v. 5, no. 2, p. 107, pi. 11, fig. 17. Cassidulina neocarinata Thalmann, 1950, Contr. Cushman Found. Foram. Res., v. 1, pts. 3-4, p. 44. Cassidulinoides erectus Cushman and Renz, 1941, Contr. i Cushman Lab. Foram. Res., v. 17, p. 25, pi. 4, fig. 6, j cibicides pseudounaerianus (Cushman) = Truncatulina pseudo- unaeriana Cushman, 1922, U. S. Geol. Survey, Prof. ! Paper 129-E, p. 97, pi. 20, fig. 9. j Gvroidina soldanii cristobalensis Bermudez = Gvroidina I mauryae cristobalensis Bermudez, 1949, Cushman Lab. | Foram. Res., Special Pub. 25, p. 253, pi. 17, figs. I 46-47. 327 j I Gyroidina soldanii soldanii d'Orbigny, 1826, Ann. Sci. Nat . j , ser. 1, v. 7, p. 278; Modeles, no. 36. j juviaerina garzaensis nudorobusta Mallory, 1959, Lower Ter- ! i tiary Biostratigraphy of the California Coast Ranges, j | Am. Assoc. Petroleum Geologists, p. 208, pi. 17, fig. ! I Astoria Formation I | ! ! I Foraminifera j i I ^ \ . 1 jPlanktonic species i i i i | | jGlobiqerina bulloides d'Orbigny, 1926, Annales Sci. Nat., I ser. 1, v. 7, p. 277; Modeles, no. 76. ; i ; ! jGlobiqerina concinna Reuss, 1850, K. Akad. Wiss. Wien, j Math.-Nat. Cl., Denkschr., v. 1, p. 37 3, pi. 47, fig. j 8. I i Globigerina conglomerata Schwager, 1866, Novara Exped., , Geol., v. 2, pt. 2, p. 255, pi. 7, fig. 113. i i 1 j Globiqerina uvula (Ehrenberg) = Pylodexia uvula Ehrenberg, | I 1861, K. Preuss. Akad. Wiss. Berlin, Monatsbre., p. 276, 277, 308. i j Globiqerinoides triloba triloba (Reuss)= Globiqerina tri- | loba Reuss, 1850, K. Akad. Wiss. Wien, Math.-Nat. Cl., Denkschr., v. 1, p. 374, pi. 47, fig. 11. Globoquadrina tripartita tripartita (Koch) = Globiqerina bulloides tripartita Koch, 1926, Eclogae Geol. Helv., v. 19, no. 3, p. 746, text-fig. 21. Globorotalia menardii praemenardii Cushman and Stainforth = Globorotalia praemenardii Cushman and Stainforth, 1945, Cushman Lab. Foram. Res., Special Pub. 14, p. 70, pi. 13, fig. 14. 328 Globorotalia scitula praescitula Blow, 1959, Bull. Am. Paleontology, v. 39, no. 178, p. 221, pi. 19, fig. 128.j jBenthic species i j lAmmonia beccarii (Linne) = Nautilus beccarii Linne, 1758, j i Syst. Nat., tomus 1, p. 710, pi. 19, fig. 1. i ! i i ! jAngu loger in a occidentalis (Cushman) = Uviger ina occide. , calisi ! Cushman, 1923, U. S. Nat. Mus., Bull. 104, pt. 4, p. i j 169. j ! i jBaqqina californica Cushman, 1926, Contr. Cushman Lab. j I Foram. Res., v. 2, pt. 3, p. 64, pi. 9, fig. 8. j iBolivina advena advena Cushman, 1925, Contr. Cushman Lab. i Foram. Res., v. 1, pt. 2, p. 29, pi. 5, fig. 1. ! I Bolivina advena astoriensis Cushman, R. E. and K. C. Stew- | art = Bolivina astoriensis Cushman, R. E. and K. C. I 1 Stewart, 1948, Oregon Dept. Geol. and Mineral Indus tries, Bull. 36, p. 47, pi. 6, fig. 3. |Bolivina advena striatella Cushman, 1925, Contr. Cushman Lab. Foram. Res., v. 1, pt. 2, pi. 5, fig. 3. I iBolivina brevior Cushman, 1925, Contr. Cushman Lab. Foram. ; Res., v. 1, pt. 2, p. 31, pi. 5, fig. 8. | i IBolivina fastigia Cushman, 1936, Cushman Lab. Foram. Res., Special Pub. 6, p. 51, pi. 7, fig. 17. I Bolivina marginata pisciformis Galloway and Morrey = Boli vina pisciformis Galloway and Morrey, 1929, Bull. Am. Paleontology, v. 15, no. 55, p. 36, pi. 5, fig. 10. Bolivina scalprata miocenica Macfadyen, 1930, Geol. Surv. Egypt, p. 61, pi. 4, fig. 22. Buccella vicksburgensis (Cushman and Ellisor) = Eponides vicksburgensis Cushman and Ellisor, 1931, Contr. j Cushman Lab. Foram. Res., v. 7, pt. 3, p. 56, pi. 7, I fig. 8. Bulimina inflata alligata Cushman and Laiming, 1931, Jour. j Paleontology, v. 5, no. 2, p. 107, pi. 11, fig. 17. Bulimina montereyana Kleinpell, 1938, Miocene Stratigraphy of California, Am. Assoc. Petroleum Geologists, p. 254,; | pi. 12, fig. 13. | ; I jBuliminella californica Cushman, 1925, Contr. Cushman Lab. j Foram. Res., v. 1, pt. 2, p. 33, pi. 5, fig. 15. ! jBuliminella curta Cushman, 1925, Contr. Cushman Lab. Foram Res., v. 1, pt. 2, p. 33, pi. 5, fig. 13. iBuliminella elegantissima (d'Orbigny) = Bulimina elegantis- j ; sima d'Orbigny, 1839, Voyage dans l'Amerique meridio- | nale, v. 5, pt. 5, Foraminiferes, p. 51, pi. 7, figs. i 13-14. I ! S iCassidella bramlettei (Galloway and Morrey) = Virgulina j ; bramlettei Galloway and Morrey, 1929, Bull. Am. Pale- i ; ontology, v. 15, p. 37, pi. 5, fig. 14. j | I iCassidulina minuta Cushman, 1933, Contr. Cushman Lab. For- ; ; am. Res., v. 9, pt. 4, no. 137, p. 92, pi. 10, fig. 3. j ; i iCassidulina neocarinata Thalmann, 1950, Contr. Cushman j Found. Foram. Res., v. 1, pts. 3-4, p. 44. I iCassidulina subglobosa Brady, 1881, Quart. Jour. Micr. | Sci., London, v. 21, p. 60. ICassidulina symmetrica LeRoy, 1944, Colorado School Mines, ' Quart., v. 39, no. 3, p. 37, pi. 5, figs. 51-52. I jCassidulinoides erectus Cushman and Renz, 1941, Contr. | Cushman Lab. Foram. Res., v. 17, p. 25, pi. 4, fig. 6. Cibicides pseudoungerianus (Cushman) = Truncatulina pseudo- ungeriana Cushman, 1922, U. S. Geol. Survey, Prof. Paper 129-E, p. 97, pi. 20, fig. 9. Epistominella carinata parva (Cushman and Laiming) = Pulvi- nulinella parva Cushman and Laiming, 1931, Jour. Paleontology, v. 5, no. 2, p. 115, pi. 13, fig. 5 330 I Epistominella relizensis (Kleinpell) = Pulvinulinella reli- j zensis Kleinpell, 1938, Miocene Stratigraphy of Cali- I I fornia, Am. Assoc. Petroleum Geologists, p. 329, pt. | 10, fig. 10. i i jEpistominella subperuviana (Cushman) = Pulvinulinella sub- | peruviana Cushman, 1926, Contr. Cushman Lab. Foram. Res., v, 2, pt. 3, p. 63, pi. 9, fig. 9. j jEoonides umbonatus (Reuss) = Rotalina umbonata Reuss, 1851,j ! Deutsch. Geol. Ges. Zeitschr., bd. 3, p . 75, pi. 5, j fig. 35. | I jGlobobu1imina ovula (d'Orbigny) = Bulimina ovula d'Orbigny, | 1839, Voyage dans l'Amerique meridionale, v. 5, pt. 5, ; Foraminiferes, p. 51, pi. 1, figs. 10, 11. I j j IGyroidina soldanii cristoba3.ensis Bermudez = Gyroidina 1 mauryae cristobalensis Bermudez, 1949, Cushman Lab. j ’ Foram. Res., Special Pub. 25, p. 253, pi. 17, figs. | | 46-47. | Hanzawaia menloensis (Rau) = Valvulineria menloensis Rau, | 1951, Jour. Paleontology, v. 25, no. 4, p. 446, pi. 66, figs. 23-25. i | I iNonion pompilioides (Fichte1 and Moll) = Nautilus pompili- I I oides Fichtel and Moll, 1798, Testacea microscopia, j p. 31, pi. 2, figs. a-c. j Nonionella boueana costifera (Cushman) = Nonionina costifera Cushman, 1926, Contr. Cushman Lab. Foram. Res., v. 1, pt. 4, p. 60, pi. 13, fig. 2. iNonionella incisa (Cushman) = Nonionina incisa Cushman, j 1926, Contr. Cushman Lab. Foram. Res., v. 1, pt. 4, ! p. 90, pi. 13, fig. 3. iNonionella lunata (Garrett) = Nonion lunatum Garrett, 1938, j Journ. Paleontology, v. 12, p. 314, pi. 40, fig. 3. I i jNonionella miocenica Cushman, 1926, Contr. Cushman Lab. | Foram. Res., v. 2, pt. 3, p. 64. Nonionella scapha basispinata (Cushman and Moyer) = Nonion pizarrensis basispinata Cushman and Moyer, 1930, Contr. Cushman Lab. Foram. Res., v. 6, p. 54, pi. 7, ! fig. 18. Planulina baaai Kleinpell, 1938, Miocene Stratigraphy of : California, Am. Assoc. Petroleum Geologists, p. 349, ; pi. 8, fig. 14. [Planulina cushmani (Barbat and von Estorff) = Cibicides floridanus cushmani Barbat and von Estorff, 1933, Jour. Paleontology, v. 7, no. 2, p. 17 3, pi. 23, fig. ; 21- jplectofrondicularia miocenica Cushman, 1926, Contr. Cushman^ Lab. Foram. Res., v. 2, pt. 3, p. 58, pi. 7, figs. 10- j 11; pi. 8, figs. 11-12. Robulus americanus (Cushman) = Cristellaria americana Cush-i ! man, 1918, U. S. Geol. Survey, Bull. 676, p. 50, pi. j i 10, figs.5,6. ; i ; ^obulus inornatus (d'Orbigny) = Robulina inornata d'Orbig- j ny, 1846, Foraminiferes fossiles du bassin tertiaire i de Vienne (Autriche), p. 102, pi. 4, figs. 25-26. j : jRobulus miocenicus (Chapman) = Cristellar ia miocenica Chap-j j man, 1900, California Acad. Sco., Proc., ser. 3 j (Geol.), v. 1, p. 250, pi. 30, fig. 1. jRobulus simplex (d'Orbigny) = Robulina simplex d'Orbigny, 1846, Foraminiferes fossiles du bassin tertiaire de Vienne (Autriche), p. 103, pi. 4, figs. 27-28. j I ! piphogenerina transversa Cushman = Siphocrenerina raphanus j j (Parker and Jones) var. transversus Cushman, 1918, | U. S. Nat. Mus., Bull. 103, p. 64, pi. 22, fig. 8. i I Sphaeroidina variabilis Reuss, 1851, Deutsch. Geol. Ges., Zeitschr., Bd. 3, p. 88, pi. 7, figs. 61-64. j I i ptilostomella adolphina (d'Orbigny) = Dentalina adolphina • ! d'Orbigny, 1846, Foraminiferes fossiles du bassin ter- j | tiaire de Vienne (Autriche), p. 51, pi. 2, figs. 18-20.j Stilostome11a advena (Cushman and Laiming) = Nodoqenerina j I advena Cushman and Laiming, 1931, Jour. Paleontology, ! v. 5, no. 2, p. 106, pi. 11, fig. 19. I I I , jSuqqrunda eckisi Natland, 1950, Geol. Soc. America, Mem. j 43, pt. 4, p. 23, pi. 9, fig. 12. I : i I iUvigerina hispida Schwager, 1866, Novara Exped., Geol. ! i Theil., Bd. 2, Abt. 2, p. 249, pi. 7, fig. 95. ! iUvigerina perearina hispidocostata Cushman and Todd, 1945, j j Cushman Lab. Foram. Res., Special Pub. 15, p. 51, pi. | j 7, fig. 31. ! i I iUvigerina subpereqrina Cushman and Kleinpell, 1934, Contr. ; Cushman Lab. Foram. Res., v. 10, pt. 1, p. 12, pi. 2, j I fig. 9. ! i 1 j j Uvigerinella californica ornata Cushman, 1926, Contr. , Cushman Lab. Foram. Res., v. 2, pt. 3, p. 59, pi. 8, j I fig. 1. j iUviqerinella obesa impolita Cushman and Laiming, 1931, ! ; Jour. Paleontology, v. 5, no. 2, p. Ill, pi. 12, fig. j iValvulineria araucana (d'Orbigny) = Rosalina araucana | d'Orbigny, 1839, Voyage dans l’Amerique meridionale, i v. 5, pt. 5, Foraminiferes, p. 44, pi. 6, figs. 16-18. ; 1 Montesano Formation j Foraminifera i i i jPlanktonic species i I jGlobiqerina bulloides bulliformis Mayer-Eymar = Globiger- | ina bulliformis Mayer-Eymar, 1887, Beitr. Geol. Karte ! Schweiz, no. 24, pt. 2, appendix, p. 123, pi. 35, fig. I 19. 333 j i I Globiqerina bulloides bulloides d'Orbigny, 1926, Annales j Sci. Nat., ser. 1, v. 7, p. 277; Modfeles, no. 76. i Globiqerina bulloides quadrilatera Galloway and Wissler = | Globiqerina quadrilatera Galloway and Wissler, 1927, Jour. Paleontology, v. 1, no. 1, p. 44, pi. 7, fig. 11 . | ; Globiqerina glutinata Egger, 1895, K. Bayer. Akad. Wiss., Math.-Phys. Cl., Abh. , v. 17, pt. 2, p. 371, pi. 13, I ; figs. 19-21. Globiqerina pachyderma (Ehrenberg) = Ar isterospira pachy- ' ' derma Ehrenberg, 1861, K. Akad. Wiss. Berlin, Monats- ; i ber., p. 276, 277, 303. j i jGlobiqerina quinqueloba Natland, 1938, Univ. California, j Scripps Inst. Oceanogr., Bull., Tech. Ser., v. 4, no. ! 5, p. 149, pi. 6, fig. 7. , I ! Globiqerina uvula (Ehrenberg) = Pylodexia uvula Ehrenberg, j 1861, K. Preuss. Akad. Wiss. Berlin, Monatsber., p. j 276, 277, 308. j Globorotalia crassaformis (Galloway and Wissler) = Globi- j | gerina crassaformis Galloway and Wissler, 1927, Jour, j j Paleontology, v. 1, no. 1, p. 41, pi. 7, fig. 12. j : i j ! Globorotalia scitula scitula (Brady) = Pulvinulina scitula j I Brady, 1882, Roy. Soc. Edinburgh, Proc. , v. 11, p. 716.j Orbulina universa d’Orbigny, 1839, in de la Sagra, His. j Phys. Pol. Nat. Cuba, Foraminiferes, p. 3, pi. 1, fig. i iBenthic species ,'Anquloqerina anqulosa (Williamson) = Uviqerina anqulosa j Williamson, 1858, Recent foram. Gt. Britain, Roy. Soc., | p. 67, pi. 5, fig. 140. Angulogerina hughesi (Galloway and Wissler) = Uviqerina ! hughesi Galloway and Wissler, 1927, Jour. Paleontolo- | <3Y> v- 1* P» 76, Pi* *-2, fig. 5. 334 Bolivina advena striatella Cushman, 1925, Contr. Cushman I ! Lab. Foram. Res., v. 1, pt. 2, pi. 5, fig. 3. I j ! jBolivina californica Cushman, 1925, Contr. Cushman Lab. I | Foram. Res., v. 1, pt. 2, p. 32, pi. 5, fig. 10. j Bolivina decussata Brady, 1881, Quart. Journ. Micr. Sci., i | v. 21, p. 28. j Bolivina marainata monicana Pierce, 1956, Jour. Paleontolo- ; gy, v. 30, no. 6, p. 1308, pi. 143, fig. 3. i jBolivina obliqua Barbat and Johnston, 1934, Jour. Paleon- j | tology, v. 8, no. 1, p. 15,pi. 1, fig.20. j j Bolivina rankini Kleinpell, 1938, Miocene Stratigraphy of. i California, Am. Assoc. Petroleum Geologists, p. 280, ! pi. 22, figs. 4, 9. j I ! I jBolivina seminuda Cushman, 1911, U. S. Nat. Mus., Bull., j j v. 71, pt. 2, p. 34, text-fig. 55. | | j Bolivina vaughani Natland, 1938, Univ. California, Scripps j Inst. Oceanogr., Bull., Tech. Ser., v. 4, no. 5, p. ! 146, pi. 5, fig. 11. Buccella be11a Bandy and Arnal, 1957, Contr. Cushman Found, j Foram. Res., v. 8, pt. 2, p. 56, pi. 7, fig. 7. ! I Buccella blancoensis (Bandy) = Eponides blancoensis Bandy, j 1950, Jour. Paleontology, v. 24, no. 3, p. 277, pi. 42, j fig. 1. [Buccella frigida (Cushman) = Pulvinulina frigida Cushman, : 1922, Biol. Board, Contr. Canadian Biol., no. 9, p. j 12 (144) . i Bulimina affinis d'Orbigny, 1840, in de la Sagra, Hist. Phys. Pol. Nat. Cuba, Foraminiferes, v. 6, p. 109, pi. j 2, fig. 25, 26. i [Bulimina subacuminata Cushman and R. E. Stewart, 1930, San I Diego Soc. Nat. Hist., Trans., v. 6, p. 65, pi. 5, j fig. 2, 3. 335 Buliminella brevior Cushman, 1925, Contr. Cushman Lab. Foram. Res., v. 1, pt. 2, p. 33, pi. 5, fig. 14. ! Buliminella californica Cushman, 1925, Contr. Cushman Lab. Foram. Res., v. 1, pt. 2, p. 33, pi. 5, fig. 15. I Buliminella curta Cushman, 1925, Contr. Cushman Lab. Foram.j | Res., v. 1, pt. 2, p. 33, pi. 5, fig. 13. J 1 | Buliminella eleaantissima (d’Orbigny) = Bulimina eleaantis- i | sima d'Orbigny, 1839, Voyage dans l'Amerique meridio- ; nale, v. 5, pt. 5, Foraminiferes, p. 51, pi. 7, figs. | 13-14. ! ICassidella californiensis californiensis (Cushman) = Virgu- I lina californiensis Cushman, 1925, Contr. Cushman Lab.j ' Foram. Res., v. 1, pt. 2, p. 32, pi. 5, fig. 11. j ( I ^assidella californiensis ticensis (Cushman and Kleinpell) = Virgulina californiensis ticensis Cushman and Klein- i pell, 1934, Contr. Cushman Lab. Foram. Res., v. 10, | p. 10, pi. 1, fig. 17. | ; i ICassidella subplana (Barbat and Johnson) = Virgulina sub- j plana Barbat and Johnson, 1934, Jour. Paleontology, j v. 8, p. 14, pi. 1, figs. 16, 17. Cassidulina delicata Cushman, 1927, Univ. California, ■ Scripps Inst. Oceanogr., Bull., Tech. Ser., v. 1, no. 10, p. 168, pi. 6, fig. 5. i Cassidulina laevigata d’Orbigny, 1826, Annales Sci. Nat., i ser. 1, v. 7, no. 1, p. 282, pi. 15, figs. 4-5. j iCassidulina minuta Cushman, 1933, Contr. Cushman Lab. For- j am. Res., v. 9, pt. 4, no. 137, p. 92, pi. 10, fig. 3. I | iCassidulina modeloensis Rankin, 1934, Contr. Cushman Lab. I Foram. Res., v. 10, pt. 1, p. 23, pi. 3, fig. 12. I i ICassidulina subclobosa quadrata Cushman and Hughes, 1925, Contr. Cushman Lab. Foram. Res., v. 1, no. 5, p. 15, | pi. 2, fig. 7. 336 Cassidulinoides cornuta (Cushman) = Virgulina cornuta Cush man, 1913, U. S. Nat. Mus., Proc., v. 44, p. 637, pi. ! 80, fig. 1. 'Cassidulinoides simplex Cushman and Todd, 1945, Cushman i Lab. Foram. Res., Special Pub. 15, p. 63, pi. 10, fig. j 15. ! j Cibicides fletcheri Galloway and Wissler, 1927, Jour. Pale-] | ontology, v. 1, p. 64, pi. 10, fig. 8, 9. j Cibicides lobatus (Montagu) = Seroula lobata Montagu, 1803, I Tes. Brit., p. 515, 516. I |Cibicides mckannai Galloway and Wissler, 1927, Jour. Pale- ] i ontology, v. 1, p. 65, pi. 10, fig. 5, 6. iCyclammina cancellata Brady, 1879, Quart. Jour. Micr. Soc., | v. 19, p. 62. | Dentalina baggi Galloway and Wissler, 1927, Jour. Paleon tology, v. 1, p. 49, pi. 8, fig. 14. i |Eggerella advena (Cushman) = Verneuilina advena Cushman, j 1922, Contr. Canadian Biol., no. 9, p. 141. lElphidium orbiculare (Brady) = Nonionina orbicularis Brady, ! 1881, Annals and Mag. Nat. Hist., ser. 5, v. 8, p. | 415, pi. 21, fig. 5. i i jElphidium rugulosum Cushman and Wickenden = Elphidium arti- culatum rugulosum Cushman and Wickenden, 1929, U. S. Nat. Mus. Proc., v. 75, art. 8, p. 7, pi. 3, fig. 8. j Epistominella bradvana (Cushman) = Pulvinulinella bradyana Cushman, 1927, Univ. California, Scripps Inst. Ocean- ! ogr., Bull., Tech. Ser., v. 1, p. 165, pi. 5, figs. I 11-13. i [Epistominella carinata pacifica (Cushman) = Pulvinulinella ] pacifica Cushman, 1927, Univ. California, Scripps Inst. Oceanogr., Bull., Tech. Ser., v. 1, p. 165, pi. I 5, figs. 14-15. 337 Epistominella carinata smithi (Stewart and Stewart) = Pul vinulinella smithi Stewart and Stewart, 1930, Jour. Paleontology, v. 4, p. 70, pi. 9, fig. 4. I iEpistominella exigua (Brady) = Pulvinulina exigua Brady, j 1884,Rept. Voy. Challenger (Zool.), v. 9, p. 696, pi. | 103, figs. 13, 14. i iEpistominella subperuviana californica White = Epistomin- ! ella pontoni californica White, 1956, Jour. Paleon- ! tology, v. 30, no. 2, p. 257, pi. 31, fig. 9a-c. i j Fissurina lucida (Williamson) = Entosolenia (Montagu) var. lucida Williamson, 1848, Ann. Ag. Nat. His., ser. 2, v. 1, p. 17, pi. 2, fig. 17. Fissurina marginata (Montagu) = Vermiculum marginatum Mon tagu, 1803, Testacea Britannica, p. 524. Fissurina oblonga (Montagu) = Vermiculum oblongum Montagu, 1803, Testacea Britannica, p. 522, pi. 14, fig. 9. Gaudryina arenaria Galloway and Wissler, 1927, Jour. Pale ontology, v. 1, p. 68, pi. 11, fig. 5. Glandulina laevigata d'Orbigny = Nodosaria (Glandulina) laevigata d'Orbigny, 1826, Annales, Sci. Nat., v. 7, j p. 252, pi. 10, fig. 1-3. Globobulimina ovula (d'Orbigny) = Bulimina ovula d'Orbigny, 1839, Voyage dans l'Amerique meridionale, v. 5, pt. 5, Foraminiferes, p. 51, pi. 1, figs. 10, 11. j Globobulimina pacifica Cushman, 1927, Contr. Cushman Lab. | Foram. Res., v. 3, no. 39, p. 67, pi. 14, fig. 12. I j iHanzawaia illingi (Nuttall) = Truncatulina illingi Nuttall, I 1928, Geol. Soc. London, Quart. Jour., v. 84, pt. 1, p. 97, pi. 7, figs. 11, 17. iHaplophragmoides columbiense Cushman, 1925, Contr. Cushman ! Lab. Foram. Res., v. 1, pt. 2, p. 39, pi. 6, fig. 2. j ibagena alcocki White, 1956, Jour. Paleontology, v. 30, no. 2, p. 246. 338 | i Laaena amphora Reuss, 1893, K. Akad. Wiss. Wien, Math.-Nat.j Cl. Sitzber., v. 46, no. 1, p. 330, pi. 4, fig. 57. j j Laaena eIonaata (Ehrenberg) = Miliola elonaata Ehrenberg, | 1844, K. Akad. Wiss. Berlin, p. 274. [ Laaena laevis (Montagu) = Vermiculum laeve Montagu, 1803, | Testacea Britannica, p. 524. j ^ I ILaaena per lucida (Montagu) = Vermiculum per lucidum Montagu,; j 1803, Testacea Britannica, p. 525, pi. 14, fig. 3. [ |Laaena substriata Williamson, 1848, Ann. Mag. Nat. Hist., j | ser. 2, v. . . p. 15, pi. 2, fig. 12. j j i ILaaena sulcata Walker and Jacob = Serpula (Laaena) sulcatai- I Walker and Jacob, 1798, Adam's Essays, Kanmacher's ed.j i p, 634, pi. 14, fig. 5. I jLoxostomum bramlettei (Kleinpell) = Bolivina bramlettei ! Kleinpell, 1938, Miocene Stratigraphy of California, | Am. Assoc. Petroleum Geologists, p. 267, pi. 21, fig. | 9- H . j jMiliammina fusca (Brady) = Ouinqueloculina fusca Brady, I 1870, Ann. Mag. Nat. Hist., ser. 4, v. 6, p. 47, pi. i 11, fig. 2. i ] ^onion affinis (Reuss) = Nonionina affinis Reuss, 1851, Deutsch. Geol. Ges. Zeitschr., v. 3, p. 72, pi. 5, fig. 32 . Nonionella lunata (Garrett) = Nonion lunatum Garrett, 1938, Jour. Paleontology, v. 12, p. 314, pi. 40, fig. 3. iNonionella miocenica Cushman, 1926, Contr. Cushman Lab. Foram. Res., v. 2, pt. 3, p. 64. Nonionella scapha basispinata (Cushman and Moyer) = Nonion pizarrensis basispinata Cushman and Moyer, 1930, Contr. Cushman Lab. Foram. Res., v. 6, p. 54, pi. 7, | fig. 18. i L 339 Pullenia salisburyi R. E. and K. C. Stewart, 1931, Contr. Cushman Lab., Foram. Res., v. 7, pt. 1, p. 15, pi. 2, fig. 15a, b. | j pyrao bulloides (d'Orbigny) = Biloculina bulloides d'Or- ! bigny, 1826, Ann. Sci. Nat., ser. 1, v. 7, p. 297, pi. j 16, figs. 1-4. I | Ouinqueloculina akneriana bellatula Bandy, 1950, Jour. ; Paleontology, v. 24, no. 3, p. 273, pi. 41, fig. 1. ! Ouinqueloculina seminula (Linne) = Serpula seminulum Linne,! 1758, Systema Nat., 10 ed., v. 1, p. 786. j I I Rotorbinella (?) garveyensis (Natland) = Rotalia qarveyensisi Natland, 1938, California Univ., Scripps Inst. Ocean- ogr. Bull., Tech. Ser., v. 4, no. 5, p. 147, pi. 6, | fig. 6. Sphaeroidina variabilis Reuss, 1851, Deutsch. Geol. Ges., Zeitschr., v. 3, p. 88, pi. 7, figs. 61-64. Uviqerina hootsi hootsi Rankin, 1934, Contr. Cushman Lab. j j Foram. Res., v. 10, p. 22, pi. 3, fig. 8, 9. i [Uviqerina hootsi modeloensis Cushman and Kleinpell = Uvi- I aerina modeloensis Cushman and Kleinpell, 1934, | Contr. Cushman Lab. Foram. Res., v. 10, pt. 1, p. 12, i pi. 2, fig. 8. i ! Uviqerina peregrina hispidocostata Cushman and Todd = Uvi- ! gerina hispidocostata Cushman and Todd, 1945, Cushman Lab. Foram. Res., Special Publ. 15, p. 51, pi. 7, fig. j 27, 31. jUvigerina sequndoensis Cushman and Galliher, 19 34, Contr. j Cushman Lab. Foram. Res., v. 10, p. 26, pi. 4, fig. 11. pviqerina subpereqrina Cushman and Kleinpell, 1934, Contr. i Cushman Lab. Foram. Res., v. 10, pt. 1, p. 12, pi. 2, figs. 9-11. Virgulinella pertusa (Reuss) = Virgulina pertusa Reuss, | 1860, K. Akad. Wiss. Wien, Math.-Nat. Cl., Sitzber., | v. 42, p. 362, 368, pi. 2, fig. 16. 340 Molluscs Acila conradi (Meek) = Nuculana conradi Meek, 1864, Check list Mio. Fossils N. Am., p. 27. jAdula falcata (Gould) = Botula falcata Gould, 1851, Proc. j Boston Soc. Nat. Hist., v. 4, p. 92. j i i Anadara devincta (Conrad) = Area devincta Conrad, 1849, j U. S. Explor. Exped. Geol., p. 726, pi. 18, fig. 10. j I i I iAnadara trilineata (Conrad) = Area trilineata Conrad, 1857,| Pacific R. R. Repts., no. 6, p. 70, pi. 2, fig. 9. | Chione ensifera (Dali) = ?Venus ensifera Dali, 1909, U. S. j i Geol. Survey, Prof. Paper 59, p. 122. ! j i jChione securis (Shximard) = Venus securis Shumard, 1858, j Trans. St. Louis Acad. Sci., v. 1, no. 2, p. 122. i I jcrepidula princeps Conrad, 1856, Pacific R. R. Repts., no. I 5, p. 326, pi. 6, fig. 52. jCyclocardia subtenta (Conrad) = Cardita subtenta Conrad, | 1849, U. S. Explor. Exped., Geol., p. 726, pi. 18, | fig. 12. Katherinella anaustifrons (Conrad) = Venus anaustifrons j Conrad, 1849, U. S. Explor. Exped., Geol., p. 724, pi. 17, fig. 11. jPenitella penita (Conrad) = Pholadidea penita Conrad, 1837, I Jour. Acad. Nat. Sci., Phila., v. 7, p. 237, pi. 18, | fig. 7. Platvodon colobus Woodring, 1940, U. S. Geol. Survey, Prof. Paper 195, p. 95, pi. 21, figs. 1, 2. Spisula albaria (Conrad) = Mactra albaria Conrad, 1848, Am. | Jour. Sci., 2nd ser., v. 5, p. 432, fig. 4. jThracia trapezoides Conrad, 1849, U. S. Explor. Exped., | Geol., p„ 723, pi. 17, fig. 6. 341 Quinault Formation Foraminifera Planktonic species iGlobiaerina bulloides d'Orbigny, 1926, Annales Sci. Nat., i ser. 1, v. 7, p. 277; Modeles, no. 76. Globiqerina qlutinata Egger, 1895, K. Bayer. Akad. Wiss., Math.-Phys. Cl., Abh., v. 17, pt. 2, p. 371, pi. 13, j figs. 19-21. 1 Globiqerina pachyderma (Ehrenberg) = Aristerospira pachv- j derma Ehrenberg, 1861, K. Akad. Wiss. Berlin, Monats- j ber., p. 276, 277, 303. Globiqerina quinqueloba Natland, 1938, Univ. California, | Scripps Inst. Oceanogr., Bull., Tech. Ser., v. 4, no. 5, p. 149, pi. 6, fig. 7. Globiqerina uvula (Ehrenberg) = Pvlodexia uvula Ehrenberg, 1861, K. Preuss. Akad. Wiss., Berlin, Monatsber., p. 276, 277, 308. Globorotalia crassaformis (Galloway and Wissler) = Globi- j qerina cr as s a formi s Galloway and Wissler, 1927, Jour. Paleontology, v. 1, no. 1, p. 41, pi. 7, fig. 12. Globorotalia puncticulata (d’Orbigny) = Globiqerina puncti- culata d'Orbigny, 1832, in Deshayes, Encyclopedie j methodique, v. 2, pt. 2, p. 170, Globorotalia scitula scitula (Brady) = Pulvinulina scitula Brady, 1882, Roy. Soc. Edinburgh, Proc., v. 11, p. 716 Orbulina universa d'Orbigny, 1839, in de la Sagra, His. Phys. Pol. Nat. Cuba, Foraminiferes, p. 3, pi. 1, fig. 1. I i Benthic species Bolivina vaughani Natland, 1938, Univ. California, Scripps Inst. Oceanogr., Bull., Tech. Ser., v. 4, no. 5, p. i 146, pi. 5, fig. 11. j Buccella friaida (Cushman) = Pulvinulina frigida Cushman, 1922, Biol. Board, Contr. Canadian Biol., no. 9, p. 12 (144). ; Buccella tenerrima (Bandy) = Rotalia tenerrima Bandy, 1950,' Jour. Paleontology, p . 278,pi. 42,fig.3. j I ! jBuliminella curt a Cushman, 1925, Contr. Cushman Lab. For am . j Res., v. 1, pt. 2, p. 33, pi. 5, fig. 13. i i ! jBuliminella eleaantissima (d'Orbigny) = Bulimina eleqantis- j sima d'Orbigny, 1839, Voyage dans l'Amerique meridio- j nale, v. 5, pt. 5, Foraminiferes, p. 51, pi. 7, figs. j 13, 14. i icassidulina limbata Cushman and Hughes, 1925, Contr. Cush man Lab. Foram. Res., v. 1, no. 5, p. 12, pi. 2, fig. I 2. ! ! jCassidulina minuta Cushman, 1933, Contr. Cushman Lab. For- | am. Res., v. 9, pt. 4, no. 137, p. 92, pi. 10, fig. 3. Cibicides fletcheri Galloway and Wissler, 1927, Jour. Paleontology, v. 1, p. 64-, pi. 10, fig. 8, 9. jCibicides lobatus (Montagu) = Seroula lobata Montagu, 1803, i Tes. Brit,, p. 515, 516. j j Cibicides mckannai suppressus Martin, 1952, Contr. Cushman I Found. Foram. Res., v. 3, pts. 3-4, p. 126, pi. 20, fig. 3 . Discorbis columbiensis Cushman, 1925, Contr. Cushman Lab. Foram. Res., v. 1, no. 11, p. 43, pi. 6, fig. 13. Elphidiella hannai (Cushman and Grant) = Elphidium hannai Cushman and Grant, 1927, San Diego Soc. Nat. Hist. Trans., v. 5, no. 6, p. 77, pi. 8, figs. 1, 2. 343 i I Elphidium frigidum Cushman, 1933, Smithsonian Misc. Coll., ; v. 89, no. 4, p. 5, pi. 1, fig. 8. ! Elphidium incertum (Williamson) = Polvstome11a umbilicatula var. incerta Williamson, 1858, Recent form. Gt. Brit ain, Roy. Soc., p. 44, pi. 3, fig. 82. | i jEpistominella carinata pacifica (Cushman) = Pulvinulinella | ! pacifica Cushman, 1927, Univ. California, Scripps j | Inst. Oceanogr., Bull., Tech Ser., v. 1, p. 165, pi. 5, figs. 14, 15. ! ! Epistominella exiaua (Brady) = Pulvinulina exiqua Brady, j 1884, Rept. Voy. Challenger (Zool.), v. 9, p. 696, pi. | 103, figs. 13, 14. > j iGlobobulimina pacifica Cushman, 1927, Contr. Cushman Lab. ! j Foram. Res., v. 3, no. 39, p. 67, pi. 14, fig. 12. j Nonionella miocenica stella Cushman and Moyer, 1930, Contr. Cushman Lab. Foram. Res., v. 6, p. 56, pi. 7, fig. 17. Nonionella scapha basispinata (Cushman and Moyer) = Nonion j pizarrensis basispinata Cushman and Moyer, 1930, Contr. Cushman Lab. Foram. Res., v. 6, p. 54, pi. 7, | fig. 18. i Plectofrondicularia californica Cushman and R. E. Stewart, ! 1926, Contr. Cushman Lab. Foram. Res., v. 2, p. 39, pi. 6, fig. 9-11. IPullenia salisburvi Stewart and Stewart, 1930, Jour. Pale- j ontology, v. 4, no. 1, p. 72, pi. 8, fig. 2. i Sugqrunda eckisi Natland, 1950, Geol. Soc. America, Me. 43, j pt. 4, p. 23, pi. 9, fig. 12. Uviqerina hootsi hootsi Rankin, 1934, Contr. Cushman Lab. Foram. Res., v. 10, p. 22, pi. 3, fig. 8, 9. Uviqerina iuncea Cushman and Todd, 1941, Contr. Cushman Lab. Foram. Res., v. 17, p. 78, pi. 20, fig. 4. ! i i r 344 Uviqerina peregrina hispidocostata Cushman and Todd, 1945, I Cushman Lab. Foram. Res., Special Pub. 15, p. 51, pi. 7, fig. 31. j i Uviqerina subperearina Cushman and Kleinpell, 1934, Contr. Cushman Lab. Foram. Res., v. 10, pt. 1, p. 12, pi. 2, figs. 9-11. / I R E F E R E N C E S CITED i REFERENCES CITED jAkers, W. H., 1954, Ecologic aspects and stratigraphic sig nificance of the foraminifer Cvclaminina cancellata ' Brady: Jour. Paleontology, v. 28, no. 2, p. 132-152. [American Commission on Stratigraphic Nomenclature, 1961, | Code of stratigraphic nomenclature: Am. Assoc. Petro-j leum Geologists Bull., v. 45, no. 5, p. 645-66 5. j I [Arnold, Ralph, 1906, A geological reconnaissance of the j ! coast of the Olympic Peninsula, Washington: Geol. Soc. I America Bull., v. 17, p. 451-468. i j | 1 | i _________, and Hannibal, H., 1913, The marine Tertiary j i stratigraphy of the north Pacific Coast of America: ( j Am. Philosophical Soc. Proc., v. 52, p. 559-605. j Bandy, 0. L., 1953, Ecology and distribution of some Cali- j fornia foraminifera, pt. 1, The frequency distribution' I of recent foraminifera off California: Jour. Paleon- ! I tology, v. 27, no. 2, p. 161-182. | _________, 1958, Dominant molluscan faunas of the San Pedro Basin, California: Jour. Paleontology, v. 32, no. 4, i p. 703-714. j _________, 1960a, Planktonic foraminiferal criteria for ! paleoclimatic zonation: Sci. Repts. Tohoku Univ., Sendai, Oapan, 2nd ser. (Geol.) special v. 4, p. 1-8. j _________, 1960b, The geologic significance of coiling ratios in the foraminifer Globiqerina pachyderma (Ehrenberg): i Jour. Paleontology, v. 34, no. 4, p. 671-681. | | _________, 1960c, General correlation of foraminiferal struc ture with environment: Internat. Geol. Cong. Repts., 21 Sess. Norden, pt. 22, p. 7-19. ____________________________________J346___________________________________ 347 Bandy, 0. L., 1961, Distribution of foraminifera, radiolaria and diatoms in sediments of the Gulf of California: Micropaleontology, v. 7, no. 1, p. 1-26. i i ! | ________ , 1963, Dominant paralic foraminifera of southern j | California and the Gulf of California: Contr. Cushman i Found. Foram. Res., v. 14, no. 4, p. 127-134. | j _________, 1964a, Cenozoic planktonic foraminiferal zonation: Micropaleontology, v. 10, no. 1, p. 1-17. i ; i | ________ , 1964b, Foraminiferal trends associated with deep- ! | water sands, San Pedro and Santa Monica Basins, Cali- j i fornia: Jour. Paleontology, v. 38, no. 1, p. 138-148. j I . . . ! ; ________, and Arnal, R. E., 1957, Distribution of Recent i i foraminifera off the west coast of Central America: j j Am. Assoc. Petroleum Geologists Bull., v. 41, p. 2037- j j 2053. j ________, and Arnal, R. E., 1960, Concepts of foraminiferal ; paleoecology: Am. Assoc. Petroleum Geologists Bull., j ' v,. 44, no. 12, p. 1921-1932. j I I ; ________ _ and Kolpack, R. L., 1963, Foraminiferal and sedi- mentological trends in the Tertiary section of Tecolote Tunnel, California: Micropaleontology, v. 9, no. 2, j | p. 117-170. ! : ________, and Echols, R. J., 1964, Antarctic foraminiferal | zonation: Antarctic Research Ser. Am. Geophys. Union, v. 1, p. 7 3-91. | ________, and Ingle, J. C. Jr., and Resig, J. M., 1964, ! Facies trends, San Pedro Bay, California: Geol. Soc. America Bull., v. 75, no. 5, p. 403-424. [Be, A. W. H., 1959, Ecology of recent planktonic foramini- | fera, pt. 1, Areal distribution in the western North j Atlantic: Micropaleontology, v. 5, no. 1, p. 77-100. i jBeikman, Helen M., Gower, Howard D., and Dana, Toni A. M., j 1962, Coal reserves of Washington: Washington Div. ! Mines and Geol. Bull. 47, 115p. 348 Bennett, W. A. G., 1939, Bibliography and index of geology j and mineral resources of Washington, 1814-1936: Wash- S ington Div. Geol. Bull. 35, 140 p. : | jBlow, W. H.., 1959, Age, correlation and biostratigraphy of j | the upper Tocuyo (San Lorenzo) and Pozon Formations, j j eastern Falcon, Venezuela: Bull. Am. Paleontology, v. j 39, no. 178, p. 67-251. ; j ! jBolli, H. M., 1950, The direction of coiling in the evolu tion of some Globorotaliidae: Contr. Cushman Found. | Foram. Res., v. 1, nos. 3 and 4, p. 82-89. Bradshaw, J. S., 1959, Ecology of living planktonic forami nifera in the north and equatorial Pacific Ocean: Contr. Cushman Found. Foram. Res., v. 10, no. 2, p. j 25-64. | ! ! j _________, 1961, Laboratory experiments on the ecology of forananifera: Contr. Cushman Found. Foram. Res., v. | 12, no. 3, p. 87-106. I jBretz, J. H., 1913, Glaciation of the Puget Sound region: Washington Geol. Surv. Bull. 8, 244 p. i jBrown, R. D. Jr., Gower, H. D., and Snavely, P. D. Jr., 1960, Geology of the Port Angeles-Lake Crescent area, | Clallam County, Washington: U. S. Geol. Survey, Map j OM-203. 'Byrne, John V., 1962, Geomorphology of the continental ter-j race off the central coast of Oregon: The Ore Bin, v. 24, no. 5, p. 65-74. I _________, and Emery, K. 0., 1960, Sediments of the Gulf of | California: Geol. Soc. America Bull., v. 71, no. 7, j p. 983-1010. | i jcarlson, P. R., and Runge, E. J., 1964, Statoliths from the I continental terrace off the coast of Oregon: unpub. Marine Nekton rept., Oregon State Univ., 32 p. Casey, R., 1963, Studies on the ecology of planktonic foram inifera and radiolaria off the southern California coast (abs.): Jour. Paleontology, v. 37, no. 4, p. 977, Culver, Harold E., 1936, The geology of Washington, pt. 1, General features of Washington geology: Washington | Div. of Geol. Bull. 32, 70 p. i I ICushman, J. A., Stewart, R. E. and Stewart, K. C., 1949, j j Quinault Pliocene foraminifera from western Washington: ; Oregon Dept. Geol. and Mineral Industries Bull. 36, I pt. 7, p. 148-162. I ;Dietz, R. S., 1952, Geomorphic evolution of continental ; : terrace (continental shelf and slope): Am. Assoc. j I Petroleum Geologists Bull., v. 36, no. 9, p. 1802-1819.1 i i jDiller, J. S., 1896, A geologic reconnaissance in north- j | western Oregon: U. S. Geol. Survey 17th Ann. Rept., ■ pt. 1, p. 441-520. i | i ; |Drooger, C. W. and Batjes, D. A. J., 1959, Planktonic for- ! | aminifera in the Oligocene and Miocene of the North j ; Sea Basin: K. Nederl. Akad. Wetensch., Proc., ser. B, j ; v. 62, no. 3, p. 172-186. j I ; I ! 'Durham, J. W., 1954, The marine Cenozoic of southern Cali- ; fornia: California Div. of Mines Bull. 170, Ch. 3, p. 23-31. _________, Jahns, R. H., and Savage, D. E., 1954, Marine- j ! nonmarine relationships in the Cenozoic section of \ California: California Div. of Mines Bull. 170, Ch. 3, p. 59-71. I j j iEames, F. E., Banner, F. T., Blow, W. H., and Clarke, W. J.j | 1962, Fundamentals of Mid-Tertiary stratigraphical j I correlation: Cambridge Univ. Press, 163 p. jEllis, B. F., and Messina, Angelina R., 1940-1965, Catalogue I of foraminifera: Amer. Mus. Nat. Hist., New York. I Emery, K. O., 1960, The sea off southern California, A modern habitat of petroleum: John Wiley and Sons, j Inc., New York, 366 p. | lEnbysk, B. J., 1960, Distribution of foraminifera in the Northeast Pacific: unpub. Ph.D. dissert., Univ. Wash ington, 191 p., 21 pis. 350 ; Ericson, D. B., 1959, Coiling direction of Globiaerina pachyderma ais a climatic index: Science, v. 130, no. | 3369, p. 219-220. j | ; Etherington, T. J., 1931, Stratigraphy and fauna of the j ! Astoria Miocene of Southwest Washington: California ! i Univ. Dept. Geol. Sci. Bull., v. 20, no. 5, p. 31-142. ' I : jEvernden, J. F., Savage, D. E., Curtis, G. H., and James, | G. T., 1964, Potassium argon dates and the Cenozoic | Mammalian chronology of North America: Am. Jour. Sci.j 1 v. 262, no. 2, p. 145-198. iFenneman, N. M., 1931, Physiography of western United | i States: McGraw-Hill, 534 p. i j i IGorsline, D. S., and Emery, K. 0., 1959, Turbidity current ; I deposits in San Pedro and Santa Monica Basins off | | southern California: Geol. Soc. America Bull., v. 70,j i no. 3, p. 279-290. j j I iGower, H. D., 1960, Geology of the Pysht Quadrangle, Wash- ; 1 ington: U. S. Geol. Survey Map GQ 129. j (Gunter, G., 1957, Temperature: Geol. Soc. America Mem. 67, ! v. 1, p. 159-184. I 1 iHarman, R. A., 1964, Distribution of foraminifera in the j Santa Barbara Basin, California: Micropaleontology, I v. 10, no. 1, p. 81-96. j Hedberg, H. D., 1934, Some recent and fossil brackish to fresh-water foraminifera: Jour. Paleontology, v. 8, ! no. 4, p. 469-476. iHedgpeth, J. W., 1957, Classification of marine environ- ) ments: Geol. Soc. America Mem. 67, v. 1, p. 17-28. I I |Hertlein, L. G. and Crickmay, C. H., 1925, A summary of the j nomenclature and stratigraphy of the marine Tertiary j i of Oregon and Washington: Am. Philosophical Soc. | Proc., v. 64, no. 2, p. 224-282. j (Highsmith, R. M., 1962, Atlas of the Pacific Northwest re- ! sources and development: Oregon State Univ. Press, jfJowe, H. V. , 1922, Faunal and stratigraphic relationships of; j the Empire Formation, Coos Bay, Oregon: California ; Univ. Dept. Geol. Sci. Bull., v. 14, p. 85-114. | i | ! | iHiilsemann, J. and Emery, K. 0., 1961, Stratification in ; i recent sediments of Santa Barbara Basin as controlled ' ; by organisms and water characteristics: Jour. Geology,; v. 69, p. 279-290. ! i ; jHuntting, M. T., Bennett, W. A. G., Livingston, V. E. Jr., j and Moen, W. S., 1961, Geologic Map of Washington: ; | Washington Div. Mines and Geol. j i I ! Ingle, J. C. Jr., 1962, Paleoecologic, sedimentary, and j ! structural history of the Late Tertiary Capistrano j j Embayment, California: unpub. MS thesis, Univ. So. | | California, 166 p., 4 pis. j i i Jarman, G. D., 1962, Recent foraminifera and associated j j sediments of the continental shelf in the vicinity of j Newport, Oregon: unpub. MS thesis, Oregon State Univ.,; Ill p ., 8 pis. jjenkins, D. G., 1960, Planktonic foraminifera from the lakes! | entrance oil shaft, Victoria, Australia: Micropaleon- I I tology, v. 6, no. 4, p. 345-371. j i i ^Cay, M., 1951, North American geosynclines: Geol. Soc. j America Mem. 48, 143 p. j Keen, M. A., 1963, Marine molluscan genera of western North 1 America, An illustrated key: Stanford Univ. Press, 126 p . I | kleinpell, R. M., 1938, Miocene stratigraphy of California: j Am. Assoc. Petroleum Geologists, 450 p. i i Kulm, L. D., and Byrne, J. V., 1964, The sediments of Ya- : quina Bay, Oregon (abs.): Conference on Estuaries, Jekyll Island, Georgia, program, p. 38. £ia Motte, R. S., 1936, Plant fossils in a marine Upper Mio- ! cene deposit near Aberdeen, Washington (abs.): Geol. I Soc. America Proc., p. 348. Livingston, Vaughn E. Jr., 1959, Oil and gas exploration in j Washington, 1900-1957: Washington Div. of Mines and j I Geol., Information Circular No. 29, 61 p. | I ! i | |Loeblich, A. R., Jr., and Tappan, H., 1964, Treatise on i invertebrate paleontology, pt. C, Protista 2 Sarcodina,1 chiefly thecamoebians and Foraminiferida: Geol. Soc. | of America, and Univ. of Kansas Press, 900 p. j Martin, L., 1952, Some Pliocene foraminifera from a portion of the Los Angeles Basin: Contr. Cushman Found. Foram. Res., v. 3, p. 107-141. | i ^ Natland, M. L., 1933, The temperature and depth distribu- ! tion of some recent and fossil foraminifera in the i southern California region: California Univ., Scripps ! | Inst. Oceanogr. Bull., Tech. Ser., v. 3, no. 10, p. j 225-230. | ; I j _________ , 1938, New species of foraminifera from off the j i west coast of North America and from the later Terti- i ary of the Los Angeles Basin: California Univ., j Scripps Inst. Oceanogr. Bull., Tech. Ser., v. 4, no. j | 5, 147 p. i s I ; i : _________ , 1953, Correlation of Pleistocene and Pliocene j stages in southern California: Pacific Petroleum i Geo1., v. 7, no. 2, p . 2. j ; _________ , 1957, Paleoecology of West Coast Tertiary sedi ments: Geol. Soc. America Mem. 67, v. 2, p. 543-572. j jParker, F. L., 1962, Planktonic foraminiferal species in j Pacific sediments: Micropaleontology, v. 8, no. 2, ! p. 219-254. i i jPease, M. H. Jr., and Hoover, Linn, 1957, Geology of the ! Doty-Minot Peak area, Washington: U. S. Geol. Survey | Oil and Gas Investigations Map OM 188. jphleger, F. B., 1951, Ecology of foraminifera, northwest | Gulf of Mexico, Part I, Foraminifera distribution: Geol. Soc. of America Mem. 46, 88 p. (Phleger, F. B., 1960, Ecology and distribution of recent ! foraminifera: The Johns Hopkins Press, Baltimore, ! 297 p. | I 'Pierce, R. L., 1956, Upper Miocene foraminifera and fish ; from the Los Angeles area, California: Jour. Paleon- | tology, v. 30, no. 6, p. 1288-1314. ! j i p.au, W. W., 1948, Foraminifera from the Miocene Astoria I | Formation in southwestern Washington: Jour. Paleon- ; tology, v. 22, no. 6, p. 774-782. ; _________, 1951, Tertiary foraminifera from the Willapa Riverj Valley of Southwest Washington: Jour. Paleontology, j I v. 25, no. 4, p. 417-453. ( | _________, 1958, Stratigraphy and foraminiferal zonation in ' | some of the Tertiary rocks of southwestern Washington: j ; U. S. Geol. Survey Oil and Gas Investigations Chart OC ; 57. I (Roberts, A. E., 1958, Geology and coal resources of the | 1 Toledo-Castle Rock district, Cowlitz and Lewis Coun ties, Washington: U. S. Geol. Survey, Bull. 1062, j 71 p . j i I ! ^ I 'Schott, W., 1935, Die foraminiferen in den aquatorealen teil des Atlantischen Oceans: Deutsche Sudpolar Exped., v. | 11, no. 6, p. 411-616. s I _ j Smith, A. B., 1963, Distribution of living planktonic for- I aminifera in the northeastern Pacific: Contr. Cushman j ' Found. Foram. Res., v. 14, no. 1, p. 1-15. ; _________, 1964, Living planktonic foraminifera collected | along an east-west traverse in the North Pacific: | Contr. Cushman Found. Foram. Res., v. 15, pt. 4, p. | 131-134. i — i (Smith, P. B., 1960, Foraminifera of the Monterey Shale and ' Puente Formation, Santa Ana Mountains and San Juan I Capistrano area, California: U. S. Geol. Survey, Prof. J Paper 294-M, p. 463-495. 354 Snavely, P. D. Jr., Rau, W. W., Hoover, Linn Jr., and i Roberts, A. E., 1951, McIntosh Formation, Centralia- | Chehalis coal district, Washington: Am. Assoc. Petro- ! leum Geologists Bull., v. 35, no. 5, p. 1052-1051. : ' i I _________, Brown, R. D. Jr., Roberts, A. E., and Rau, W. W., ■ 1958, Geology and coal resources of the Centralia- ! Chehalis district, Washington: U. S. Geol. Survey, Bull. 1053, 143 p. j i ________ , and Wagner, Holly C., 1953, Tertiary geologic j history of western Oregon and Washington: Washington Div. of Mines and Geology, Rept. of Investigations No. j I 22, 25 p. ; Walton, W. R., 1952, Techniques for recognition of living i foraminifera: Contr. Cushman Found. Foram Res., v. 3, ' ; p . 56-50. : i i - j ________ , 1955, Ecology of living benthonic foraminifera, Todos Santos Bay, Baja California: Jour. Paleontology,; | v. 29, no. 6, p. 952-1018. j I Weaver, C. E., 1912, A preliminary report on the Tertiary j paleontology of western Washington: Washington Geol. | ! Surv., Bull. 15, 80 p. ! j ; ________, 1916, The Tertiary formations of western Washing- j ton: Washington Geol. Survey, Bull. 13, 327 p. i ; j ■ ________, 1937, Tertiary stratigraphy of western Washington | and northwestern Oregon: Washington Univ. (Seattle) Pub. Geol., v. 4, 266 p. i ________, 1943, Paleontology of the marine Tertiary forma tions of Oregon and Washington: Washington Univ. (Seattle) Pub. Geol. v. 5, Nos. 1, 2, and 3, 789 p. I ________, and western Cenozoic Subcommittee, 1944, Correla tion of the marine Cenozoic formations of western North America: Geol. Soc. America Bull., v. 55, p. j 569-598. Wheeler, H. E. and Mallory, V. S., 1963, Regional Tertiary sequences in the Pacific Northwest: Geol. Soc. Ameri- | ca, Special Paper 15, p. 73-74. 1 iWilliams, H., Turner, F. J., and Gilbert, C. M., 1954, Petrography: An introduction to the study of rocks in thin section: W. H. Freeman and Co., San Francisco, 406 pp. Wissler, S. G., 1943, Stratigraphic formations of the pro ducing zones of the Los Angeles Basin Oil Fields: California Div. Mines Bull., 118, p. 209-234. Woodring, W. P., Stewart, R., and Richards, R. W., 1940, Geology of th^ Kettleman Hills oil field, California: U. S. Geol. Survey, Prof. Paper 195, 17 0 p. ; _________ , Bramlette, M. N., and Kew, W. S. W., 1946, Geo logy and paleontology of Palos Verdes Hills, Califor- j nia: U. S. Geol. Survey, Prof. Paper 207, 145 p. | __________ and Bramlette, M. N., 1950, Geology and paleon tology of the Santa Maria District, California: U. S. | Geol. Survey, Prof. Paper 222, 185 p. Wurden, F. H., 1959, What are the prospects in Washington State? World Oil, v. 149, no. 1, p. 94-98. Youngquist, Walter, 1961, Annotated lexicon of names applie to Tertiary stratigraphic units in Oregon and Washing ton west of Cascade Mountains, with bibliography: Edwards Brothers, Inc., Ann Arbor, Michigan, 92 p ., 2 charts.

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Creator Fowler, Gerald Allan (author)

Core Title The Stratigraphy, Foraminifera, And Paleoecology Of The Montesano Formation, Grays Harbor County, Washington

Degree Doctor of Philosophy

Degree Program Geology

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Geology,OAI-PMH Harvest

Format dissertations (aat)

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Bandy, Orville L. (committee chair), Easton, William H. (committee member), Reith, John W. (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c18-178392

Unique identifier UC11359603

Identifier 6512258.pdf (filename),usctheses-c18-178392 (legacy record id)

Legacy Identifier 6512258.pdf

Dmrecord 178392

Document Type Dissertation

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Rights Fowler, Gerald Allan

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Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

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