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Marine Geology Of The Santa Catalina Basin Area, California

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Marine Geology Of The Santa Catalina Basin Area, California

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Content ( Thle dlsewUtlon ha» been mlarofllmed e*acUy •• **celved 66—8787 . ■ GAAL, Robert Arthur Paul, 1929- MARINE GEOLOGY OF THE SANTA CATALINA BASIN AREA, CALIFORNIA. University of Southern California, Ph.D., 1966 Geology University Microfilms. Inc., Ann Arbor, Michigan / MARINE GEOLOGY OF THE SANTA CATALINA BASIN AREA, CALIFORNIA by Robert Arthur Paul Gaal 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) January 1966 UNIVERSITY OP SOUTHERN CALIFORNIA THK ORADUATC SCHOOL U N IV K M IT V PARK LOS A N Q K LU , CALIFO RNIA S 0 0 0 7 This dissertation, written by __ under the direction of Aift— Dissertation Com- mittee, and approved by a ll 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 O F P H IL O S O P H Y Date.... January*. . l . 9. 6 . 6. DISSERTATION OOMMITTEE ... 1 CONTENTS Pago ABSTRACT ..............................................xv INTRODUCTION ...................................... 1 General statement................................ 1 Location........................................ 2 Previous work.................................... 4 Acknowledgments.................................. 4 BATHYMETRY....................... 6 Physiographic classification .................... 6 General features................................ 6 Bathymetric trends .............................. 10 Ridges............................................ 12 Lands lides........................................ 12 Terraces.......................................... 13 Basin parameters ........................ 14 OCEANOGRAPHY.......................................... 15 General statement.................................. 15 Drainage.......................................... 15 ii Page Wind, waves, tides, and currents.............. 17 Sound velocity, temperature, pressure and salinity data............................ 20 STRUCTURE.......................................... 27 Structural framework.......................... 27 Geomorphic interpretations .................... 30 Seismicity.................................... 32 Refraction seismic data........................ 35 Magnetic data.................................. 42 Gravity d a t a .................................. 50 Acoustic reflection data (electrosonic profiler).................................... 55 - Age and origin of the Santa Catalina Basin ... 64 RESULTS OF CORES AMD DREDGES...................... 69 Core results.................................. 69 Interpretation................................ 73 Dredge haul results............................ 75 BOTTOM PHOTOGRAPHY................................ 83 X-RADIOGRAPHY...................................... 86 SEDXMENTOLOGY .......................... 88 iii Page General statement.............................. 88 Size analyses.................................. 88 Texture.................................... 91 Sediment type...................... 91 Mean diameter....................... . 97 Standard deviation................. . . 100 Skewness . . . . . . . . . . . . . . . . 104 Kurtosis.......................... 106 Coarse fraction analyses .................... 110 MINERALOGY OF SEDIMENTS.............................. 117 General statement................................ 117 Heavy minerals............................ 118 Light minerals............................ 129 CLAY MINERALOGY...................................... 132 General statement................................ 132 Methods.......................................... 133 Results.......................................... 135 GEOCHEMISTRY........................................ 138 General statement................................ 138 Calcium carbonate analyses ............. 138 iv Page Organic constituents .......................... 144 Nitrogen analyses .......................... 144 Organic carbon analyses .................... 150 Organic matter ............................ 154 Spectrochemical analyses...................... 157 Major elements............................ 157 Minor elements............................ 163 FORAMINIFERA...................................... 190 Methods........................................ 190 Foraminiferal analyses ........................ 190 SUMMARY AND CONCLUSIONS............................ 201 REFERENCES........................................ 212 APPENDIXES........................................ 222 Appendix A: Continuous sound velocity, tempera ture, and depth data for the Santa Catalina Basin area, California . . . 224 Appendix B: Station locations................... 249 Appendix C: Semiquantitative spectrographic analyses of the 0-3 cm surface inter val of some Santa Catalina Basin area cores.............................. 254 Appendix Dt Spectrochemical ratios of some Santa Catalina Basin area samples ........ 266 v LIST OF TABLES Table Page 1. Temperature-salinity data for Station N0TS-10, November 2, 1964 .......................... 26 2. Semiquantitative spectrochemical analyses of dredged rocks from the Santa Catalina Basin, California........................ 79 3. Textural parameters of surface (0-3 cm) samples of the Santa Catalina Basin, California................................ 90 4. Coarse fraction analyses of surface (0-3 cm) samples of the Santa Catalina Basin, California................................ Ill 5. Comparison of percentage, frequency number, and proportion analyses nomenclature .... 119 6. Heavy mineral composition of Santa Catalina Basin Area surface sediments.............. 121 7. Light mineral composition of Santa Catalina Basin Area surface samples............ 130 8. Percentage of clay minerals in the Santa Catalina Basin Area, California .......... 136 9. Geochemical characteristics of Santa Catalina Basin Area sediments...................... 140 10. Foraminifera of the surface interval (0-3 cm) of the Santa Catalina Basin System, California................................ 192 vi LIST OF PLATES Plate Page I. Bathymetric Chart of the Santa Catalina Basin Area, California .................... pocket II. Bathymetry of the Emery Seaknoll, Santa Catalina Basin, California ................ pocket III. Bathymetry of Osborn B a n k ....................pocket IV. Photographs of Representative Cores of the Santa Catalina Basin, California ............ 72 V. Photographs of Thin Sections of Andes ite Autobreccia (A) and Phosphorite Nodule (B) Dredged from the Emery Seaknoll at a Water Depth of about 780 Meters at 33°021 N Lat., 118°23' W Long......................... 77 vii LIST OF ILLUSTRATIONS Figure Page 1. Index map of the Santa Catalina Basin Area, California............. 3 2. - Physiographic provinces of the Santa Catalina Basin, California ........................ 7 3. Location map of echo sounding lines for the Santa Catalina Basin, California .......... 8 4. Station location map for continuous sound velocity, temperature and pressure data for the Santa Catalina Basin Area, California................................ 21 5. Continuous sound velocity profile along line A, Santa Catalina Basin, California . . 22 6. Continuous temperature profile along line A, Santa Catalina Basin, California .......... 23 7. Continuous temperature profile along line A, Santa Catalina Basin, California .......... 24 8. Continuous temperature profile along line C, Santa Catalina Basin, California .......... 25 9. Generalized geologic map of the Santa Catalina Basin and adjacent area, California .... 28 10. Earthquake epicenter location map of the Santa Catalina Basin and adjacent area, California ........................ 33 11. Location map of seismic refraction lines in the Santa Catalina Basin, California .... 37 viii Figure Page 12. Seismic refraction structure section, profiles of Total Magnetic Anomaly, Bouguer Gravity Anomaly, and Bathymetry along line A—A* of the Santa Catalina Basin, California .... 38 13. Seismic refraction structure section, profiles of Total Magnetic Anomaly, Bouguer Gravity Anomaly and Bathymetry along line B-B' of the Santa Catalina Basin, California .... 39 14. Geomagnetic map of the Santa Catalina Basin and adjacent area, California ............ 44 15. Bouguer Gravity Anomaly map of the Santa Catalina Basin and adjacent area, California................................ 51 16. Ship track lines for continuous sub-bottom acoustic reflection records (electrosonic profiler) for the Santa Catalina Basin, California............................. 57 17. Electrosonic records and interpretative profiler sections along lines 25, 30 and 3 4 ................................. 58 18. Electrosonic records and interpretative profiler sections along lines 19 and 32 . . 59 19. Electrosonic records and interpretative profiler sections along lines 24 and 38 . . 60 20. Electrosonic records and interpretative profiler sections along lines 14, 21 and 2 6 ................................. 61 21. Structural contours on apparent reflector horizons "A".and "BM for the Santa Catalina Basin, California ................ 63 22. Core and dredge sample location map of the Santa Catalina Basin, California ........ 70 ix Figure Page 23. Bottom photographs of the San Clemente slope at a water depth of about 800 meters at 33°01' N lat., 118°31* W long........................................ 84 24. X-radiograph sections (left photos) and photographs (right photos) of representa tive cores of the Santa Catalina Basin, California................................. 87 25. Probability cumulative curves for Santa Catalina Basin Area surface sediments ... 92 26. Frequency polygons and histograms for Santa Catalina Basin Area surface sediments ... 93 27. Texural triangular composition diagram of Santa Catalina Basin sediments ............ 95 28. Sector diagram for the per cent of sand, silt, and clay in the surface interval 0-3 cm of the Santa Catalina Basin, California .... 96 29. Distance distribution of standard deviation, arithmetic mean, skewness, and kurtosis of the Santa Catalina Basin, California .... 98 30. Relationship between median diameter and depth in the Santa Catalina Basin........ 99 31. Relationship between median diameter and trask sorting coefficient of surface sediments........................ 101 32. Relationship of mean diameter versus standard deviation and skewness of surface sediments.................................. 103 33. Relationship of mean diameter versus standard deviation and kurtosis of surface sediments.................................. 108 x Figure Page 34. Relationship between skewness and kurtosis of surface sediments......................109 35. Variation of composition for the surface interval of the 0.25-0.061 mm fraction of a SW-NE cross section of the Santa Catalina Basin, California ...... ... 112 36. Variation of composition for the surface interval of the 0.25-0.061 mm fraction of a NW-SE cross section of the Santa Catalina Basin, California ....................... 113 37. Variation of composition for the surface interval of the 0.25-0.061 mm fraction of a SW-NE cross section of the Santa Catalina Basin, California ..... ............. 114 38. Relationship of per cent total sand versus per cent of Mica, Foraminifera and Radiolarians of the surface sediments....................116 39. Variation of composition of the surface interval of light and heavy mineral assemblages for the 0.25-0.061 mm fraction of a SW- NE cross section of the Santa Catalina Basin, California.................................. 122 40. Variation of composition of the surface interval of light and heavy mineral assemblages for the 0.25-0.061 mm fraction of a NW-SE cross section of the Santa Catalina Basin, California..................123 41. Variation of composition of the surface interval of light and heavy mineral assemblages for the 0.25-0.061 mm fraction of a SW-NE cross section of the Santa Catalina Basin, California ............... 124 xi Figure Page 42. Relationship between CaCC>3 and median diameter of surface sediments............ 141 43. Relationship between CaC<>3 and depth in the Santa Catalina Basin, California . , 142 44. Relationship of mean diameter versus standard deviation and CaC03 of surface sediments................................143 45. Distribution of total calcium carbonate content of the Santa Catalina Basin, California................................ 145 46. Surface sediment variation of per cent CaC(>3, total organic matter, nitrogen, mean grain diameter, and standard deviation with depth across three transects of the Santa Catalina Basin, California .......... 146 47. Distribution of organic nitrogen of the Santa Catalina Basin, California .......... 147 48. Relationship of mean diameter versus standard deviation and nitrogen of surface sediments ........ ... ..... 148 49. Relationships between nitrogen and median diameter of surface sediments.............. 149 50. Relationships between nitrogen and depth in the Santa Catalina Basin .................. 151 51. Relationships between CaC<>3 and nitrogen of surface sediments........................ 152 52. Distribution of organic matter of the Santa Catalina Basin, California ................ 155 53. Variation of total organic material versus percentage of clay-size fraction and diatoms and radiolarians.............. 156 xii Figure Page 54. Variation in the ratio of total iron to, total aluminum with percentage of total aluminum.................................... 164 55. Variation in the ratio of total strontium to total calcium with percentage of total calcium.............................. 166 56. Variation in the ratio of total barium to total potassium with percentage of total potassium................. 168 57. Variation in the ratio of total barium to total sodium plus potassium with percentage of total sodium plus potassium...............169 58. Variation in the ratio of total boron to total aluminum with percentage of total aluminum.................................... 172 59. Variation in the ratio of total copper to organic carbon with percentage of organic carbon ............................ 175 60. Variation in the ratio of total chromium to organic carbon with percentage of organic carbon...................................... 177 61. Variation in the ratio of total vanadium to organic carbon with percentage of organic carbon...................................... 179 62. Variation in the ratio of total gallium to organic carbon with percentage of organic carbon......... 181 63. Variation in the ratio of total nickel to total aluminum with percentage of total aluminum.................................... 184 xiii Figure Page 64. Variation in the ratio of total cobalt to total aluminum with percentage of total aluminum.................................. 185 65. Variation in the ratio of total nickel to organic carbon with percentage of organic carbon....................................186 66. Variation in the ratio of total cobalt to organic carbon with percentage of organic carbon....................................187 9 xiv ABSTRACT The Santa Catalina Basin lies in the Continental Bor derland off southern California at an intermediate distance between the nearshore and offshore basins. This northwest- southeast trending trough is unique among the Borderland basins because it is bounded by islands; on the north by Santa Barbara, the west by San Clemente, and the east by Santa Catalina. Bathymetrically, the basin is bordered by steep, straight escarpments, and is extremely flat-floored. Seismic epicenters concentrated along the southeastern extension of the San Clemente "rift" zone indicate that faulting is, or has been, an active process in the develop- j ment of the basin and probably represents an adjustment to larger-scaled borderland stresses. Faults, folds, and un conformities interpreted from electrosonic profiler records of the basin indicate a structural evolution similar to the onshore basins. These structures may represent important future potential oil traps. 'Electrosonic profiler data re veal sediment to be thickest in the marginal troughs and thinnest in the central part of the basin along its north- south axis. Marginal troughs fronting San Clemente and Santa Catalina Islands contain 0.4 km and 0.3 km of uncon- formable unconsolidated sediment, ranging from probably Pliocene to Recent in age, respectively. A large, northwest-trending positive 1500-gamma mag netic anomaly centers just west of San Clemente Island. Along the island's eastern base, a prominent negative ano maly trends northwest, suggestive of a fault. Bouguer gravity data show a closed, confound negative anomaly over the basin, and significant positive anomalies over the Emery Seaknoll and portions of Santa Catalina Is land. San Clemente Island exhibits a prominent positive magnetic anomaly; however, it is the only large topographic high in the area not associated with a major bouguer ano maly. xv .j Most of the small amount of sand now entering the basin Is derived primarily from the surrounding Islands. Some deep basinal cores contained evidence reflecting displaced units and possible turbidity currents. Abundant phosphorite and glauconite occur on the Emery Seaknoll. Andesite auto- : breccia dredged from the Emery Seaknoll indicated a volcanic origin, presumably related to the Middle-Miocene andesites on nearby San Clemente Island. Clayey silt is the dominant size mode in the 0- to 3-cra surface sediment interval. Mean diameters range from 0.323 per cent respectively, and the C/N ratio is 9.5. Markedly fresh orthopyroxene, primarily hypersthene, is the most abundant heavy mineral in the surface sands. Horn blende is subordinate with lesser amounts of augite, epi- dote, actinolite, and chlorite. The unstable orthopyroxene- hornblende assemblage is a first-cycle product of erosion from a mixed volcanic and metamorphic terrain. Suggestive also of a volcanic source are the unusual abundance of plagioclase feldspar, and the lack of potash feldspar. Montmorillonite, as shown by X-ray analysis, is the dominant clay in the <2|i fraction, with moderate amounts of illite, and minor portions of kaolinite. The low value for kaolinite and illite in the <2|i fraction is due to possible ! differential flocculation and size fractionation near shore with deposition and concentration into the >2\i fraction. Semiquantitative, spectrochemical analyses of the sur- , face sediment revealed that its chemical composition is controlled primarily by the clay minerals. Of the 200 species of foraminifera recognized in the surface interval, only 20 are living forms. A comparison of coiling ratios of Globiaerina pachvderma (Ehrenberg) with depth in core AHF 8424 yielded an uncorrected rate of sedi mentation of 2.5 cm/100 years. A foraminiferal zone between two volcanic units on Santa Barbara Island, along the basin margin, indicated a Middle Miocene, Early Luisian age. Similar faunas from strata on San Clemente Island are also Luisian. xvi INTRODUCTION General Statement A study of the Santa Catalina Basin was undertaken in order to obtain and integrate the various marine geologic parameters affecting the nature of this transitional basin which lies between the nearshore and offshore basins. Until this study, there has been no intensive research in the basin, although Shepard and Emery (1941) studied the Contin ental Borderland in general and Emery (1960) presented a summation of what had been accomplished in the area to that date. Bathymetric, surface, and coring operations were begun in 1962 aboard the Allan Hancock Research Vessel Velero IV. A series of oceanographic cruises devoted to the study of the area aboard several United States Navy vessels followed. A total of 80 days were spent at sea and over 500 miles of echo sounding tracks were covered. Forty-four sediment cores, 9 rock dredges, and 5 grab samples were obtained. 1 Location 2 Santa Catalina Basin is an elongate trough in the Con tinental Borderland Province (Shepard and Emery, 1941) of the southern California offshore area (Fig. 1). The Con tinental Borderland Province consists of ridge and trough bathymetry bordering the West Coast of North America between Point Conception, California (32.5° N) and Viscaino Penin sula, Baja California, Mexico (28° N). The Catalina basin is unique among the series of basins off southern California in that it is bounded on three sides by islands. Santa Catalina Island lies to the east, Santa Barbara Island is on the northern margin, and San Clemente Island bounds the western edge of the basin. This inter island basin lies in an intermediate position between the nearshore basins on the north and east such as Santa Barbara Basin, Santa Monica Basin, San Pedro Basin, and the San Diego Trough and the offshore basins on the west, such as Tanner Basin, Long Basin, and Velero Basin (Fig. 1). The approximate boundaries of the basin are 33° 40* N. latitude and 119° 10* W. longitude, and 32° 50* N. latitude and 118° 02* W. longitude. I 1 1 9 * KILOMI l A N t A C I t . LOS ANGELES $ M * r * VO*fC4 *4*1* ■ \ 9 4* * . ft 0*0-. o II* • MC0L4 9 AN OICOO 1 > < s > »«• INDEX MAP OF THE SANTA CATALINA BASIN AREA, CALIFORNIA FIGURE I Previous Work 4 Although this is the first detailed study of the Santa Catalina Basin, the area and surrounding basins have been explored in a general way by Shepard and Emery (1941), who contoured United States Hydrographic Office Chart 1006. Emery (1960) and associates made restricted studies in the area which are included in his book The Sea Off Southern California. Although various oil companies and the United States Navy have studied parts of the area in detail, their data have been classified and are unavailable to date. Acknowledgments The writer acknowledges especially the support and constructive criticism throughout the project of Or. Donn S. Gorsline. Doctors O. L. Bandy, R. Merriam, J. W. Reith, and R. O. Stone suggested important revisions. J. R. Curray, J. C. Harrison, D. Moore, G. Shaefer, and O. W. Scholl furnished unpublished geophysical and bathymetric data. I. R. Kaplan and R. Rex offered constructive sugges tions and reviewed portions of the manuscript. Partial reduction of the foraminiferal material was done by the Shell Oil Company and the Chevron Research Company afforded 5 use of X-ray facilities. The project was partially supported by the Geological Society of America and the National Science Foundation. K. Green offered great encouragement and many valuable suggestions regarding the foraminiferal study and J. Clements assisted in the drafting of charts. » I i BATHYMETRY Physiographic Classification According to Heezen (1963), the Continental Margin is divided into three categories of provinces of which the Santa Catalina Basin is an example of a Ridge-Basin Complex Province. The principal physiographic divisions as shown in Figure 2 are largely descriptive and are used in designating areas of reference in the text. General Features The bathymetry of the Santa Catalina Basin area is known partly from Coast and Geodetic Survey soundings, pub lications of Shepard and Emery (1941), Emery (1960), United States Naval Ordnance Test Station data, and surveys made by the writer on cruises of the Velero IV and three naval ships from 1962-1964 (Plate 1). Figure 3 shows the ship track lines from which soundings were obtained. Depths were recorded as continuous profiles on a Precision Depth 6 7 S I * - 4 t f •OOUNOMV or MVM- wunoc MOVIMCI •Arrn<MiiMTt m u n o m v ■ POtTUlATCO MCCHT 0 (Ut'OCCXMT KOI HINT TMJCCTORlia ♦ O ' ♦ o ' is PHYSIOGRAPHIC PROVINCES OF THE SANTA CATALINA BASIN. CALIFORNIA n o * FIOUMI 8 •o ' If. i i i * IM U IIO IM I m o i / f r t i m i » LOCATION MAP OF ECHO SOUNDING LINES FOR THE SANTA CATALINA BASIN, CALIFORNIA. •VIA* C«U>M ft'J *114* M44C0U #*l*«04Tlt* C*gil| N H K I ^nlATiM C>giftl IIV v M t o tvi» c « v m . n c 4 ,m : Ulfel M V II CO lH K , * • » |,I 9 M * • * • iCU »•♦* C*g<»C* m I .4 H 4 Uf t Recorder manufactured by the Times Facsimile Corporation and a Precision Graphic Recorder made by Litton Industries. Both are used in conjunction with an BIX) UQN-1E sonar sounding set. In coastal areas visual bearings and radar ranges on known points were obtained to locate the sounding lines. In the outer portions of the basin shipboard radar was used for locations and minor inaccuracies can be expect ed . Precise surveying over a portion of the San Clemente shelf and an adjacent submarine high using theodolites and land-based ranging radar gave locations to within less than 50 feet at 20 mile distances and much greater precision nearshore. In general, the bathymetric charts were drawn with some interpretation and much "contour license" because of uneven ship track spacings, the navigational uncertainties, and the presence of areas of highly irregular bathymetry. Depths were read and plotted at 3-minute intervals. Soundings were initially recorded in fathoms, assuming a nominal sound velocity of 4800 ft/sec and later converted to meters; these soundings have not been corrected for local variation in water characteristics or for other echo sounding corrections such as side-echo effects and slope corrections. The un certainties of the navigational inaccuracies have been 10 lessened by adjustments of the crossings of ship tracks. Although location errors may exist, it is believed that features on the Emery Seaknoll bathymetric chart (Plate II) are located to within 50 yards beyond 10 miles from Santa Catalina Island and possibly within 50 feet within 10 miles of San Clemente Island. The positions of soundings of the Osborn Bank Chart (Plate III) sure accurate to about 150 feet horizontally. Charts constructed from uncorrected echo soundings have the advantage that they can be used by ships equipped with standard sonar devices without the bother of reconverting. However, charts in this report are based upon the metric system for efficiency and in anticipation of eventual con version of American sonar devices to the metric system. Bathymetric Trends Although two marked topographic trends appear within the region, the more dominant is the northwest-southeast trend and a modifying east-west trend. The northwest- southeast trend extends from the southern Continental Bor derland (Krause, 1961 and 1965) to the northern channel is lands where it is indistinct and the east-west trend pre dominates . Bathymetrically the Santa Catalina Basin is a more or less flat-floored closed basin covered largely with olive green clayey silts. This basin has one of the flattest floors of the basins close to shore. The topography is an index to the amount and manner of filling of the basin. If this basin is believed to be of comparatively recent origin, then the relatively small supply of sediment that is con tributed from the surrounding area should not fill it with sediment. It is bordered by apparent "scarps" on either side and has been considered to be a graben or rift valley by some geologists and possibly even a faulted syncline. Because of the straight steep escarpment bordering both Santa Catalina and San Clemente Islands, Shepard and Emery (1941) and Emery (1960) interpreted the basin as a fault trough. Bathymetric expression indicates that an east-west profile is asymmetric along the island fronts, suggesting that the relatively steeper slope of the San Clemente Island escarpment is younger than the gentler escarpment of Santa Catalina Island. A slope-apron complex is indicated along the western escarpment of Santa Catalina which is absent along most of the San Clemente Island area. An oval-shaped high in the basin is herein named the Emery Seaknoll in recognition of K. 0. Emery, who pioneered studies in the Continental Borderland (see Plate II). 12 Ridges The origin of the ridges surrounding the Santa Catalina Basin is speculative; however, three origins are proposed. Folding, faulting, and termination of submarine volcanic flows are possible ridge-formers in the submarine environ ment. Electrosonic profiler data suggest that the ridge form ing San Clemente Island may be a combination of volcanic and structural origin. To what extent faulting or folding (warping) is dominant is unknown, yet folding is evident in the electrosonic profiler records of the basin. The ridge to the west-northwest of Santa Catalina Island is most probably fault-controlled, as pre-Tertiary metamorphics have been dredged along its west flank at AHF station 8426. Landslides Recognition of landslides is determined from fathograms by the uneven nature of the bottom topography, abnormal slopes, hummocky slopes, cirque-like depressions, and anti thetical slopes. Materials at the base of the San Clemente escarpment slopes and the western slopes of the Emery 13 Seaknoll are believed to be landslide debris. Gravity sliding may be an important sediment contributor to the basin floor, especially in this area of relatively high seismicity. Terraces i Emery (1958 and 1960) described submarine terraces in the Continental Borderland and attributed them to marine processes of erosion during lower stands of sea level. Al though some terraces are attributed to erosion and/or depo sition, such as Emery's "five separate flattenings" which sure reportedly consistent in the northern borderland, others may have been constructed by such phenomena as faulting, landslide or slumping, volcanic flows or resistant sills. However, similar features at the same depth around the is lands may suggest a primary origin by erosion, or by flows or sills. The western edge of a terrace-like feature is in some cases deeper than the eastern margin, as on San Cle mente Island. A seaward and southward deepening of the shelf-break occurs from 75 m at Los Angeles to 145 m at 32° N. latitude. The great depth of some terrace-like features leads to speculation as to whether or not the lowering of sea level 14 was very much (greater than 200 m) and, also, whether much of the area now underwater was exposed in intervening time. These speculations have led some investigators to the theory of a subaerial origin for submarine canyons and turbidity mechanisms for sand deposition in basins. Basin Parameters Two sills occur in the Santa Cataline Basin at depths of 975 and 983 m, respectively. The depth of bottom is 1360 m and the difference between effective sill depth and bottom is 377 m. The area of the basin is approximately 2150 km® and the volume is about 435 km3. OCEANOGRAPHY General Statement Data on water characteristics of the Santa Catalina Basin are fragmentary and have been obtained from several sources. Emery (1960) compiled most of the oceanographic data available up to that time. These data were gathered from reports of the Allan Hancock Foundation, the Scripps Institution of Oceanography, the United States Fish and Wildlife Service, and the California Division of Fish and Game. The California Cooperative Fisheries Investigation has published yearly data on surface characteristics in the area since 1953. Recently, the United States Navy, the Allan Hancock Foundation, and the Los Angeles County Museum have gathered data on various parts of the basin. Drainage No permanent streams occur on the islands surrounding the Santa Catalina Basin. Intermittent streams contain 15 16 running water only for a short period of time after rains which occur infrequently during the winter. During and shortly after periods of heavy rainstorms, the larger steep ravines and canyons on Santa Catalina and San Clemente Is lands may channel sediment-laden water into the ocean. This discharge causes a discoloration in the surface and near surface layers for several hundreds to thousands of feet offshore and this condition has been observed by the writer to remain for several days. Perennial springs occur on both the larger islands. However, runoff from these springs is negligible. In most places the axial drainage divide of San Cle mente Island is near the upper edge of the eastern escarp ment. The drainage system is poorly developed on the pre cipitous east side of San Clemente Island, where gradients are exceedingly steep, especially along the escarpment. Although the mouths of all the stream channels appear ac cordant with sea level, some gulley-like canyons have an hourglass pattern near their debouchement area, suggesting a # rapid incising as a result of a relative drop in sea level. The western slope of the island is dissected by a series of relatively steep-sided gulley-like canyons. Many of the upper reaches of the stream courses are poorly defined, 17 whereas father downslope sharp steep-walled V-shaped canyons have been cut by the streams. Although over 85 per cent of the discharge from the island flows into San Nicolas Basin, San Clemente Island is considered one of the chief sources of Recent stream-borne sediment in the western portion of the Santa Catalina Basin. The chemical composition of the runoff waters from the pre dominantly andesitic rocks forming the island would presum ably be high in calcium, magnesium, iron, and minor elements such as chromium, vanadium, strontium, and nickel. Over two-thirds of the drainage on Santa Catalina Is land flows into the basin. More than 75 per cent of the discharge is channeled towards the Catalina Canyon sediment cell complex. Probably only small amounts of sediment reach the basin from Santa Barbara island. Wind, Waves, Tides, and Currents The prevailing wind in the area is from the northwest. Even though daily winds may depart from the annual average, the northwesterly pattern is reasonably constant. Sometimes in the summer a general counter-clockwise eddy is generated north of Santa Catalina Island. At other times of the year, ' excluding summer, strong hot dry sediment-bearing winds, Santa Anas, blow from the desert area seaward. These winds are believed to be an important source of Recent sediment to the offshore area and large dust-laden clouds have been observed several miles off the southern California coast by this writer. It should be noted that smog particles escap ing the Los Angeles Basin are also potential sediment con tributors to the nearshore and intermediate offshore basins. Wave patterns in the basin are, in general, controlled by the prevailing winds, whereas the swells cure usually generated from storm centers in the North Pacific west of California. Emery (1960) made an interesting study of the swell and wave patterns of the northern Continental Border land from a seaplane. On October 15, 1957 (0900-1500 hours) his observations indicated a pattern of crossing wave trains consisting of swells from two distant offshore storm centers and of waves from local winds. These included a long period swell from the northwest, an intermediate swell from the west and local wind waves from the north-northwest. The local wind waves were refracted the most as they passed through the Santa Catalina Basin area and the long period swells were affected least. The very complicated patterns of crossing sea and swell often seen in the basin are caused by the interference of the many islands in the area and by 19 the smaller reflected waves. Internal waves were measured by Emery (1956) in the Santa Catalina Basin over a 25-hour interval. Standing oscillations with a period of 2 hours and an amplitude of 200 m were recorded. Emery (1956) believed that his data suggested the presence of one or more standing internal waves having a node near the center of the basin. Interest ingly enough, these waves may transmit sufficient energy to generate bottom currents which in turn could produce sedi ment movement on the deep basin floor and also could produce submarine erosion along the margins of the basin. Tidal observations have been recorded from only a few locations. Recently, tides have been measured at Catalina Harbor, Santa Catalina Island, and Wilson Cove, San Clemente Island. The diurnal tide curves of the area are character ized by asymmetry in that there is usually one cycle of greater range and one of lesser range. Diurnal tides have a slightly greater velocity than the semi-diurnal tides. The period of the diurnal current is 25.1 hours and the velocity averages 0.3 foot/sec. According to Emery (1960), tidal currents in the region move from southeast to the northwest. The velocity of the tidal current is greater during the ebb tide when the water mass is moving toward 20 the southeast because the general mass transport of water from the northwest is added to it. Little is known of current velocities within the basin. Current measurements using a modified Roberts Current Meter at depths of less than 600 feet of water along the northeast side of San Clemente Island indicated velocities of about 0.1 ft/sec. No bottom current velocities have been measured to date. Sound Velocity, Temperature, Pressure, and Salinity Data . Continuous sound velocity, temperature, and pressure data (SVTP), using a Ramsey Probe, were obtained for the basin and immediate area during a November 2, 1964 cruise aboard the USNS Davis. These data are tabulated in Appendix A. Station locations are shown in Figure 4 and distribution 1 diagrams for sound velocity and temperature versus depth sure found in Figures 5, 6, 7, and 8. The average temperature and salinity for the basin is 4.02° C and 34.43 °/oo, respectively (Emery, 1960). Temper ature and salinity data from a Nansen cast for November 2, 1964, at station NOTS-10 are listed in Table 1. 21 i w r * f t t M M i IT- STATION LOCATION MAP FOR CONTINUOUS SOUND VELOCITY, TEMPERATURE,AND PRESSURE 0A1A FOR THE SANTA CATAUNA BASIN AREA, CALIFORNIA. Uftfeft mm CMtmtt * * km HMtn ■Lfcfithfl I M » V l l l C I 1 V , T ( H » I M ( b l | M m iim i iwmi K U M l « (Nil M * • i i W f • K M N I M l V •* aft ftiM tr. • « * £E mm CONTINUOUS SOUND VELOCITY PROFILE ALONG LINE A SANTA CATALINA BASIN. CALIFORNIA. m m i I * * * * * 8 r «r CONTINUOUS TEMPERATURE PROFILE ALONG LINE A SANTA CATALINA BASIN. CALIFORNIA n w w w m w n i cumuic K> Ul tvr»4 IVTM IfVI m * riMMt^r CONTINUOUS TEMPERATURE PROFILE ALONG LIN E A SANTA CA1AUNA BASIN. CAUFORNIA m WtP* it a* e n CONTINUOUS TEMPERATURE PROFILE ALONG LINE C SANTA CATALINA BASIN. CALIFORNIA i w n i w n • H i m timm ii 26 TABLE 1 TEMPERATURE-SALINITY DATA FOR STATION NOTS-IO, NOVEMBER 2, 1964 Depth (m) T °C S °/oo 0 18.87 33.85 10 18.82 33.83 19 18.60 33.81 29 14.66 33.41 48 12.61 33.60 72 11.29 33.88 96 10.64 33.81 144 9.99 34.04 192 9.66 34.26 288 34.24 386 8.00 34.32 483 6.83 34.25 581 6.03 34.29 776 5.01 34.45 972 4.10 34.58 1168 34.55 1463 2.83 34.55 1955 2.70 34.49 STRUCTURE Structural Framework Structurally, southern California is a region of in tense faulting and folding. Folded structures on land may be related to faults such as occur along the Newport- Inglewood uplift (Woodford and others, 1954). Krause (1961) indicated that important folding on land was related to causal faults and that the faults were generally much longer than the folds. It is very likely that in the offshore area similar rock structures are present. Consequently, as in the Los Angeles Basin area the structure of the Continental Borderland may be thought of in terms of analogy, that is, presumably faulted and folded structures occur below the Recent sediment cover. A perusal of geologic maps which border the offshore area as well as maps of the Channel Islands indicate substantial folding and faulting (see Fig. 9). Furthermore, sonoprobe profiles (Moore, 1960) and electrosonic profiler or Arcer studies (Curray, 1964 and 27 28 p p p r N tttfu r L0C4U D TILT IQ U fM GENERALIZED GEOLOGIC MAP OF THE SANTA CATALINA BASIN AND ADJACENT AREA.CALIFOHNA. MOL M M BATA MMlFitl tfUl IS|lT CM m tanfMWi com mam smct olmsm A M MOL«0V H U B • A M MAP C A M M A F A Q M M I O M O H I t T M OCALf IfM J T Q ' MNLT M M fiQU-UOS j ) post « MCtMI M MB* _ I Ml Lo»«f Mmfiif lw AM/or •AO*# K+<»n» T* lwlp| Vfl^Ki 29 Scholl, 1964, personal communication) show considerable folding and faulting in and below pre-Pleistocene shelf sediments of the Continental Borderland. A concept of the northern Continental Borderland is necessary as a basis for further discussion. The northern Continental Borderland is a broad shelf area, characterized by low, flat-topped ridges and banks (Shepard and Emery, 1941). Several marked trends appear in the region, especi ally the surficially dominant northwest-southeast trend and a modifying east-west trend. Fourteen closed basins exist and they sure depicted as nearshore, transitional, and off shore basins (see Figure 1). Structurally, the Santa Cata lina Basin and adjacent insulsur areas sure regions of appsur- ent vertical and possibly lateral movements. Over 6400 feet of appsurent relative vertical displacement is indicated by "Franciscan-type" schists on Santa Catalina Island. Rela tive lateral movements sure conjectural and thrusting, sug gestive of compressional or gravitational forces, has been indicated by Bailey (1941) on Santa Catalina Island. Some of the local structural anomalies appear to be adequately explained by normal gravitational forces, although lsurger regional anomalies may be the result of isostatic adjustment to thick sedimentsury accumulation, from movements 30 associated with warping or displacement of the basement rock, or from the emplacement of plutons. Larger anomalies than previously reported have been suggested by Harrison (1965, personal communication) trending east-west in the basement rock which now exhibit a superficial northwest- southeast trend. Inferences as to the geologic structures of the area are dranw from insular geologic maps, geomorphic features from the bathymetric chart, sub-bottom continuous acoustic reflection records (electrosonic profilers), magnetic, gravity, seismic refraction, and earthquake epicenter data. Even a general knowledge of known insular geology along with bathymetry may be misleading when making structural interpretations. Therefore, it is believed that the dis cussion of structure based upon an integration of the afore mentioned data will provide the present most probably pic ture of the area. Geomorphic Interpretation Geomorphic features on the deep-sea floor are rela tively reliable indicators of tectonic structures because weathering and erosion are presumed to be relatively in active modifying agents in the marine environment. Any 31 modification that occurs on the sea floor is doubtless due either to mass movement of rock or sediment or to "normal" processes of sedimentation. The bathymetry of the Santa Catalina Basin may reflect similar structural features as occur on the surrounding land areas. A great deal of prudence must be applied when deal ing with the interpretation of structure from bathymetry alone. Prominent apparent structural trends are evident from the bathymetric chart of the basin (see Plate I). Emery (1960) listed criteria for assessing fault origin of sea floor scarps taken from bathymetry such as straightness, offsets, height, steepness, step-like profiles, and linear depressions at the base. The scarps bordering the north east side of San Clemente and the southwest side of Santa Catalina Island suggest fault bathymetry (Plate I). Whether or not a fault offset controls Santa Catalina Canyon is purely conjectural. Of interest is the north-south align ment of the Palos Verdes Hills, Santa Catalina Island, and San Clemente Island, all of which are at about the same elevation. The sub-rounded plan, conical shape, and rela tively steep slopes of the Emery Seaknoll suggest a volcanic structure. The highly irregular bathymetry along the south western slope suggests a breached or faulted portion of the 32 structure. Seismicity The Santa Catalina Basin is within the Offshore Seismic Province of Richter (1958), and is bounded on all but the west by the Coastal Stable Block Province, the Hurray Frac ture Zone and adjacent Transverse Range Seismic Province, and the Baja California Stable Area, respectively. The Inglewood Fault zone may represent the eastern boundary? however, the northwest-trending fault near the northern margin of the Palos Verdes Hills which passes westward into the Santa Monica Basin may be the more important structural boundary. Early workers, including Wood (1947), Clements and Emery (1947) and Emery (1960) showed correlations of epi centers with known and inferred faults in southern Califor nia. Progrsummed epicenter data from January 5, 1934 to May 7, 1963 were obtained from the California Institute of Technology Seismological Station and these data were plotted on a chart showing location, quality of location, intensity, and depth (see Fig. 10). About 100 earthquakes having epi centers of A or B quality (surficial locations believed accurate to within 5 km) and having a magnitude 3 or greater 33 Oo o ®; 00, oo o 00 oo ol OD • * h n• at »• •N - u1 I* EARTHQUAKE EPICENTER LOCATION MAP OF THE SANTA CATALINA BASIN AND ADJACENT AREA* CALIFORNIA. v lacmrmat AC***'! f* mv UH «■ * tmm hwi •uu iitun O i o u i« iu v cacti O l% hoc*tii umiTufli o* o*» o» o « « M HfMCIVAHailMiJn M Ml 34 on the Richter scale were recorded. The restriction to high quality locations and high magnitude shocks insures suffi cient accuracy to indicate relationships to known topograph ic and structural features. Although most epicenters are concentrated in the land area of southern California, some epicenters occur in the offshore area of which the greatest concentration occurs near San Clemente Island, in the southwest portion of the Santa Catalina Basin (see Fig. 10). The northeast scarp of San Clemente Island is one of the steepest and straightest in the region. This escarpment is traceable northwestward and southeastward by "submarine rift" topography as well as by the general trend of earth quake epicenters. All epicenters in the offshore area had foci less than 16 km deep. The most recent data obtained which had accurate depth determinations for the offshore area indicated that foci were no deeper than 9.2 km on Santa Catalina Island, and no greater than 8.2 km in the northeast portion of the Santa Catalina Basin. Seismic activity in the offshore area is low to moderate and the largest recorded shock in the basin was magnitude 5.9 which occurred near the southeast tip of San Clemente Island. Even though seismic evidence is scant, the distribution 35 of large long linear, steep scarps in an area of otherwise flat bottom suggests that faulting is or has been an active process. Seismicity occurring at present is concentrated along the southeastern extension of the San Clemente "rift" zone and probably represents adjustment to larger-scaled borderland stresses. Refraction Seismic Data Interpretation of the deep structure of the Santa Catalina Basin is based largely upc:: the seismic refraction studies of Shor and Raitt (1958). The theory behind seismic refraction profiling has been thoroughly discussed by Dobrin (1960). In principle, a sound field is created, usually by explosives, and the minimum time required for the sound pulse to travel from one point to another is determined. A travel-time plot of the sound travel-time against the trave1-distance yields a graph with points that lie in characteristic patterns as segments of straight lines. These data can be related to the structure of the earth's crust through which the waves passed and each array of points or line segments represents the arrivals from separ ate layers within the crust. The velocity of the compres sions! sound wave through a layer is found from the inverse 36 slope of the line and the depth of the layer is determined from the intercept of the line with the time axis. Shor (1963) described the field methods used by the Scripps Institution of Oceanography for seismic refraction work at sea. The computational methods were similar to those used by Katz and Ewing (1956). On Figure 11 positions of seismic refraction profiles by Shor and Raitt (1958) are shown, and a portion of two of their composite seismic refraction profiles are presented on Figures 12 and 13 respectively. These workers summarized their results as follows: 1. Thickness of unconsolidated sediment is small on the ridges, great under portions of the interior basins and the inner continental shelf. 2. The upper continental crust is present under some of the ridges and basins. 3. The typical oceanic crust with velocity 6.7 km/sec is continuously present across the borderland. 4. The Mohorovicic discontinuity systematically in creases in depth toward the continent, with most of the depth increase accounted for by thickening of the oceanic (lower continental) crust. Shor and Raitt (1958) indicated the base of the t 37 » U KAT ION M A P OF SEIS MIC R E F R A C T IO N UN C S J N THE SANTA C A T A U N A BASI N. CALI FORNIA mmmmmut mm w i n mtmm 38 I - I - I t "* ! • I - •M TOTAL MdQWttlC m m m Mfllll * ■ W t l H i m iaai « i ommc W fM CtioN n w u c rw i a n n o * m o n u s o r to w . mmmvc m m i x m m m m t u t n MmuxMomwMTmiumumA'itviMuimamm9Hm.t*urQm»ik. 39 t - I f i - TOTAL MAONITI6 . m a v it t iiio m iu m o n u A to m • » * *« imc n Minn i n m m nivac i i REF RACT ION STR UC TUR E secti on, pr o fi les o f total m ag neti c ANO MA IX B O U G U E R GRAVITY ANOMAU ANO BATH YM ETR Y A L O N G LINE B -tf OF THE 8AN1 A CA1A U NA BASM, CALIFORNIA. unconsolidated sediment in the Santa Catalina Basin to be 1 1/2 km and the base of the next layer of consolidated sediment, (4.31-4.87 km/sec) at 3 km except at the north west end, where the base of the second layer drops to 5.2 km below sea level. These depths are in sharp contrast to the adjacent basins, such as Santa Cruz and San Nicolas, where sedimentary fill is estimated to be 5 to 7 km below sea level. Curiously enough, the depth to the base of the combined unconsolidated-consolidated sediment and/or vol- canics is similar to the depth to "basement" in the deep oceanic area west of the Patton Escarpment which is consid ered to be the margin of the continental shelf. This simi larity indicates that oceanic "basement" (6.7 km/sec) is present as far east as the Santa Catalina Basin. The presence of rock with velocity 5.8 km/sec as the upper layer of the crystalline crust under the Santa Cata lina Basin suggests that the continental crust is present as far west as San Clemente Island. From San Clemente Island westward, the 5.8 km/sec layer is apparently lost and seem ingly the west flank of the deeper rodks comprising San Clemente Island and lying under the San Nicolas basin repre sent the western margin of continental crustal rocks in the area. Rocks with velocity 5.8 to 6.2 km/sec are comparable 41 to the granitic rocks of the southern California Batholith and similar rocks crop out at the southern tip of Santa Catalina Island* Presumably they sure of the same age. The Mohorovicic discontinuity beneath the Santa Catalina Basin is at a depth of about 24 km. Using the densities given by Worzel and Shurbet (1955), Shor and Raitt deter- ) ined the depth at which the Mohorovicic discontinuity should lie beneath this basin. The computed value of 26 km is very close to the observed value of 24 km. It is inter esting to note that the depth of the Mohorovicic discontin uity at the base of the outer continental slope is 9 to 11 km and increases in depth towards the continent, being 24 km under the Santa Catalina Basin and increasing to 32 km under the Peninsular Ranges. Shor and Raitt account for this in crease in depth by the thickening of the 6.7 km/sec "oceanic crust" landward. According to Krause (1961), the San Diego Trough to Santa Barbara Island crustal section is in iso static equilibrium with the thick crust at Corona, Califor nia, and with the oceanic crust just west of the Patton Escarpment. Recently, there has been considerable controversy as to where to place the boundary between the continental and oceanic regions off southern California. Ordinarily, the 42 margin of the continents is taken where the continental slopes lead directly to the deep sea floor. Oceanic crust is considered by some to be under oceanic depths, that is, where the water depth is greater than 4 km (Menard, 1964). The offshore seismic province lies east of what is normally considered to be the boundary for oceanic and continental rocks. Menard (1964) believed that the region off southern California is an exception to the normal boundary definition in that faulting has produced a transitional zone of basins and ridges at the continental margin. The crust under the southern California Borderland was believed by Press (1956) to be oceanic and he suggested that the Mohorovicic discon tinuity may stand at or near the oceanic level. Shor and Raitt (1958), however, believed that the small and relative ly shallow basins off southern California are down-faulted blocks of continental crusts. Magnetic Data Magnetic data were obtained from J. C. Harrison of Hughes Research Laboratories, Malibu, California. These data were collected from cruises of the Tilman J., a Hughes Aircraft Company vessel, and the USNS Davis, a United States Navy Oceanographic ship. A total intensity proton 43 precession ship-towed magnetometer was used in the survey; the theory and use of this equipment has been fully dis cussed by Bullard and Mason (1963). The magnetic anomalies in the area are believed to be caused by magnetic minerals, such as magnetite or maghemite, spatially arranged by geo logic processes in the crustal rocks which, in turn, cure superimposed on the geomagnetic field produced by the core mantle complex. Although Bromery, Emery, and Balsley (1960) made an airborne reconnaissance survey in 1949, the magnetic survey of Harrison represented the first detailed study of the area and his magnetic data were recontoured and a total magnetic field intensity map constructed (see Fig. 14). Information regarding the magnetic susceptibility of the rocks and geo thermal, radioactive element, or heat flow data for the area was not available, and no corrections were made for diurnal and magnetic storm fluctuations of the Earth's mag netic field. Thus, the origin of the magnetic anomalies must be viewed in light of the aforementioned and therefore the origin of these anomalies generally is speculative and unknown. Mason (1958) believed that the maximum depth to the top of the geologic structures which caused the magnetic anomalies in this part of the borderland is probably less 44 41 GEOMAGNETIC MAP OF THE SANTA CATALINA BASIN AND ADJACENT AREA. CALIFORNIA t o t a l f i e l o m a g n e tic i n t e n s i t y IN GAMMAS: ADO 4 9 ,0 0 0 TO ALL VALUES MMfiC NTI U M 4CTIC t W T M M ' l l h f i l • m MM M»eOtf*Ll> MM U K III t l l C M t t M IM I H«» I 45 than 11 km. Emery (1960) reported the results of the first published aerial reconnaissance magnetic survey in the area and Krause (1961, 1965) indicated that the same general features appear in the Southern Borderland as well as a large 1500 gamma anomaly at San Clemente Island. More recently, Harrison and von Huene (1965) discussed the magnetic and gravity ano malies of the region in more detail. For the Santa Catalina Basin, it is assumed that the configuration or distribution of mass occurs at one level since most magnetic anomalies are due to susceptibility con trasts in the basement. Therefore, the magnetic anomaly map is considered to be a reflection of the slope of the basement and depths can be approximated. Two profiles of total magnetic intensity, corrected for regional gradient by inspection from United States Navy H. 0. Chart 1703 are shown in Figures 12 and 13. These pro files have been integrated into a diagram with other geo physical and bathymetric data in order to show general re lationships and to make interpretations more readily dis cernible. It should be noted that the magnetic map is not obviously geological in nature and therefore not directly indicative of structure. Consequently, a large degree of 46 interpretation and integration with the other data must be applied to bring out the subtle relations to geology. A distinctive pattern of the geomagnetic field is shown in Figure 14 which is apparently related to the geology? the anomalies generally trend northwest-southeast. The trend is broken at the northern channel islands where disruption causes an east-west trend coincident with the Transverse Ranges. The linear anomalies appear to be discontinuous and probably represent fault zones which are presumably represented in the bathymetry. The east-west anomalies may also be discontinuous. Generally, the anomalies have sharp inflections and are associated with local bathymetric fea tures . Possible origins for the anomalies are speculative; however, the larger anomalies appear to be correlative with the larger tectonic and bathymetric units. The magnetic trends are compatible to known structural trends onshore and consequently may reflect a similar origin. An examination of the magnetic map (Fig. 14) indicates a very large positive anomaly that trends in a northwesterly direction a few miles to the west of San Clemente Island. The east flank of this anomaly coincides with the eastern escarpment of the island. This major anomaly has a value of 47 1500 gammas. Although the positive anomaly dissipates near the southern tip of San Clemente island, it continues north ward, broken only by a saddle parallel to the ridge connect ing with Santa Barb aura Island. A very prominent negative anomaly trends northwesterly along the base of San Clemente Island that extends from the southern tip of the island to approximately 20 miles south west of Santa Barbara Island. The large positive magnetic anomaly a few miles to the west of San Clemente Island indicates a highly magnetic body at depth which presumably is a large basic or ultrabasic pluton. Emery (1960) mapped a fault along the entire length of the San Clemente escarpment. The magnetic data are not entirely consistent with this interpretation because this important feature apparently disappears about halfway along the island. If the escarpment represents a fault of pre sumably large displacement, then we must explain the appar ent cessation of the anomaly. Krause (1961 and 1965) en countered a similar situation along the San Benito Ridge in the southern borderland. The anomaly may have disappeared due to one or all of several possibilities: (1) fault off set, (2) occurrence of nonmagnetic rock in the north, (3) 48 the curie temperature is extremely shallow to the north, (4) magnetic basement is at greater depths to the north result ing in no anomaly. Alternate explanations may be that the island is the edge of a relatively magnetic volcanic flow (Harrison, personal communication, 1965), or it may repre sent an igneous rock facies transition such as from rela tively magnetic basalt to relatively non-magnetic andesite, or it may be a fault dying out in a large fold. There is a profound change in the bathymetric depth along the San Clemente escarpment with the bathymetry dropping from 1280 meters in the Santa Catalina Basin to 2090 meters in the San Clemente Basin, which suggests a possible hinging mechanism. The trend of the feature is consistent with the regional structure and therefore may represent a lateral fault of large displacement. Krause (1961) believed that a fault borders the east flank of San Clemente Island which is right lateral and continues southeastward intermittently toward the Punta Banda branch of the Agua Blanca fault, but did not quite connect these. He (1961) also observed that the northern borderland is moving west relative to the southern portion along the Santo Tomas fault, an east-west branch of the Agua Blanca fault. This implied that much of the defor mation occurring in the Northern Borderland is expended in 49 the Santo Tomas sheen: zone. Curiously enough, this pattern of movement is sympathetic with the theory that the Pacific Ocean basin is moving northwest relative to the borderland and continent. A zone of tension apparently caused by the interaction of the ocean basin movement and the opposing borderland movement results in the Santo Tomas shear zone which appears to be coincident with the en echelon volcanoes farther offshore in the Pacific basin. The origin of the Santa Catalina Basin is purely con jectural. Santa Catalina Basin may be a simple graben bounded by normal faults due to northeast-southwest tension- al stress, or it may represent a depression in an imbricated west to east thrust fault pattern of large magnitude. A phase change or a thinning of the crust due to stretching beneath the basin may have caused the depression. So-called "normal" crust may be absent and the depression could repre sent a large tensional crack. The basin possibly may be a large syncline bounded on the east and west flanks by the antiform San Clemente and Santa Catalina Islands. Possibly a combination of all these factors fits the general regional picture. Gravity Data 50 Computerized gravity meter data were kindly made avail able by J. C. Harrison of the Hughes Research Laboratories at Malibu for the Santa Catalina Basin area. These data were contoured and a Bouguer anomaly map, based upon an assumed density of 2.35 gm/cc was constructed (Fig. 15). Most of the gravity measurements were made with a LaCoste- Romberg surface-ship gravity meter (Harrison and von Huene, 1965). The methods and theory of surface-ship gravity meters are described by Worzel and Harrison (1963) and the accuracy of data in the Continental Borderland and adjacent areas was thoroughly discussed by Harrison and Mather (1964) and Harrison and von Huene (1965). The gravitational method is based on the measurement of the variation in the acceleration due to gravity at the sea- level surface. As these variations are caused by changes in the distribution of mass beneath the shipborne meter, cor rections such as variations for the depths of water and surrounding bathymetry must be made. The resulting correct ed gravity anomalies are then assumed to be caused by den sity variations beneath the sea floor. Anomalies can be caused by lateral density changes that are not caused by BOUCUER GRAVITY ANOWALY HAP OF THE SANTA CATALINA BASIN AND ADJACENT AREA,CALIFORNIA structure at all. Harrison and von Huene (1965) used a compromise density of 2.35 gm/cc for the basis of their Bouguer anomaly maps of the Northern Continental Borderland; the same density is used in this study. It should be noted that a unique solution for sub-bottom structure cannot be obtained from a gravity profile because there is generally no single solution to the problem of finding a mass distri bution that will produce the measured gravity field. Conse quently, for any set of data there are an infinite number of interpretations which are theoretically possible. Therefore, numerous assumptions and integration with other geophysical data must be made before satisfactory structural deductions of gravity anomalies may be rendered. However, when gravity data are combined with the results of seismic refraction studies, the layering determined from refraction studies can be used in the solution of the gravity profile, and the gravity data thus fill the gaps between the seismic lines (Shepard, 1963). An examination of the Bouguer Anomaly Map (Fig. 15) shows a closed compound negative gravity anomaly over the more or less flat-bottom Santa Catalina Basin and positive anomalies over the Emery Seaknoll and Santa Catalina Island. Curiously enough, San Clemente Island is the only 53 topographic high in the area not associated with a major Bouguer anomaly, although it does exhibit a prominent mag netic anomaly. Harrison and von Huene (1965) inferred the presence of a great thickness of uniformly magnetized igne ous rocks, presumably of vesicular texture or low density, as the cause. Although the exposed rocks on San Clemente Island are mostly volcanic, no magnetic property data of these rocks have been published. Extending these inferen ces further, the San Clemente Island-Ridge structural high may represent a linear "pile of volcanics," the escarpments being the margins of massed flows. This is, indeed, implied by Harrison and von Huene (1965). These prominent closed anomalies, as well as others on the map, coincide with known geological or topographic features. One of the most prominent positive anomalies in the area diverges from the San Clemente Ridge and runs southeast from Santa Barbara Island for about 20 miles and terminates near the deepest part of the San Nicolas Basin. According to Harrison and von Huene (1965), this gravity high does not correspond with a major topographic feature and its inter pretation as a major basement uplift could be in doubt al though an electrosonic profiler section indicates that it coincides with a minor ridge on the floor of the eastern 54 part of the San Nicolas Basin. Because the gravity anomaly coincides in most part with the observed magnetic anomaly, it seems highly plausible that a causative relationship exists. Therefore, a deduction may be made that there is a probable basic or ultrabasic intrusion or an anomalous fea ture in the basement which may cause both anomalies as there is a relationship between the gravitational and magnetic potential of a body. Where there is a gravity anomaly and no magnetic ano maly, as in parts of the Santa Catalina Basin and the adja cent San Nicolas Basin, it is deduced that sedimentary structures are present. Depths to basement in the area may be approximated by using a figure of 240 ft/milligal. Harrison and von Huene (1965) concluded that the cor respondence between their gravity anomalies and topography suggested that the smaller scale variations on their gravity map sure primarily due to changes in the thickness of the sedimentary layers and in the depth to basement. They also believed that gravity lows marked basins of thick sediments, the highs indicated sureas of shallow, or even exposed, base ment. These hypotheses sure corroborated by the strong cor relation between anomalies and known geologic structures, such as the coincident gravity highs and exposed basement 55 rocks on Santa Catalina Island (see Figs. 9 and 15). A very interesting analysis of the small and large scale variations of the Northern Continental Borderland gravity field was published in 1965 by Harrison and von Huene. The east-west trending patterns found for intermed iate and long wavelength variations are believed to be due to basenent topography and variations in sediment thickness. The reduction analysis eliminated the surficial northwest- southeast trending grain associated with the Coast Ranges by an averaging process. This east-west trend parallels the Murray fracture zone offshore and the transverse structures nearshore and onshore. Consequently, Harrison and von Huene (1955) believed that in all probability these east-west features represent an older grain in the area which has been largely obliterated by the northwest trending Coast Range structures. Acoustic Reflection Data (Slectrosonic Profiler) Unpublished sub-bottom continuous acoustic reflection records of a 1964 cruise in the basin from a Rayflex electro- sonic profiler, hereafter referred to as ESP, have been kindly furnished through the courtesy of D. W. Scholl, 56 United States Naval Ordnance Test Station, China Lake, California. A supplementary line through the basin was obtained from J. R. Curray, Scripps Institution of Oceano graphy, La Jolla, California. The theory, instrumentation, methods, and interpreta tion of acoustic reflection profiling have been discussed by Curray and Moore (1964). According to Curray and Moore (1964), interpretation of ESP records is complicated and a significant amount of intuitive geologic reasoning is re quired in their analysis. Structural interpretations based on ESP profiles sure highly desirable because they sure be lieved to approximate structural cross-sections. Their reliability has been corroborated by geologic data. Over 150 miles of lines, whose locations are shown in Figure 16, were analyzed and interpreted. The ESP records presented with interpretative line drawings and described in captions (Figs. 17 to 20) were selected to indicate per tinent structural features and lithologic units within the area. Various surfaces, believed to represent significant geologic horizons, were correlated between adjacent survey lines. These surfaces were postulated in order to estab lish a sequence of possible events which may be extrapolated into a chronology of the depositional and structural history 57 SHIP TRACK LINES FOR CONTINUOUS SUB-BOTTOM ACOUSTIC REFLECTION RECORDS (ELECTROSONIC PROFILER) FOR THE SANTA CATALINA BASIN. CALIFORNIA. h o c u p •Biimii Mlw* WMNl Mill . V I M " I W I W M M I H I B IWI • ] ESP LINE 90 ESP LINE ELECTRO-SONIC PROFILER RECORDS ALONG LINES 2 5 ,3 0 Al sw Me m SANTA CATAUMA BASIN M£ SAMTA C SLOB t INTERPRETATIVE Foult" Unconformity * ** ** ** SANTA C A T A L IN A sim . sa sw N i ESP LINE 25 sa n C L U tem m o u 4 N T A G A T ALINA BASIN ESP LINE 30 S A N T A C A TA LIN A Sim SSI ESP LINE 34 INTERPRETATIVE PROFILER SE C TIO N S A LO N G LINES 25,30 A N O 34 NO SC ALE FIGURE 1 7 j i Ct .V ESP LINE 19 J & * ESP LINE 32 ELECTRO-SONIC PROFILER RECORDS ALONG LINES 19 AND 32 EMERY SEAKNOLL SAN CLEMENTE ESCARPMENT ESP LINE 19 SAN : CLEMENTE RI06E SANTA CATALINA BASIN NE ESP LINE 32 INTERPRETATIVE PROFILER SECTIONS ALONG LINES 19 AND 32 NO SCALE Fault Unconformity FIGURE V . ' ESP LINE 24 ESP LINE 38 ELECTRO-SONIC PROFILER RECORDS ALONG LINES 24 AND 38 60 EVERY SEAKNOLL ESP LINE 24 SE SAN1 M M SLOPE i ; , i v 4 t\; A.^ /vir ESP LINE 38 INTERPRETATIVE . PROFILER SECTIONS ALONG LINES 24 AND 38 NO SCALE Foul! —— Unconform ity FIGURE 19 ESP LINE 14 S i t ! > > ! ' * ESP LINE 21 SANTA ESP LINE 26 INTERPRETATIVE ELECTRO-SONIC PROFILER RECOROS ALONG LINES 14,21 AND 26 F a u lt » U nconform ity — SAN CLEMENTE NIECE SW ESP LINE 14 SAN CLEMENTE ESCARPMENT SW NE ESP LINE 21 SANTA CATALINA RIDCE NE ESP LINE 26 INTERPRETATIVE PROFILER SECTIONS ALONG LINES 14,21 AND 26 F o u lt ■ Unconform ity NO SCALE FIGURE of the basin. Probable structural contours determined from uncorrected survey lines are shown in Figure 21. The corre lated surfaces represent the predilections of this writer and, in reality, may not truly represent a true fossil sur face but only an apparent acoustic reflecting horizon or break in the apparent morphology of the reflected units. For coherent sub-bottom reflections near the surface, an assumed sound velocity of 1.8 km/sec was used; assumed velocities of 2.8 to 3.8 km/sec were used for reflections of poor coherence below the 1.8 km/sec reflections. Lines 25 and 30, an east-west profile across the basin (Fig. 17), show that linear marginal depressions occur along the base of both Santa Catalina and San Clemente Islands. Also, this section as well as line 34 indicated that sedi ment is relatively thick (0.5 km) in the marginal troughs and exceptionally thin (0.25 km) in the central put of the basin along its north-south axis. The unconformities repre sented along the margins of these troughs are believed to be Pliocene to Recent in age. A marginal depression along the base of the east flank of San Clemente Island apparently deepens towards the south and shallows rapidly in the area immediately west of the Emery Seaknoll (see line 19, Fig. 18). Line 32, Figure 18, however, reveals that the trough + r i l l * 00' tmutnr ifoi.im STRUCTURAL CONTOURS ON APPARENT REFLECTOR HORIZONS “A " AND "B* FOR THE SANTA CATALINA BASIN, CALIFORNIA. - SCALE I; 2 3 4 .2 7 0 C0NT0U4 HtTCNVAL 100 MCTCRt FIGURE 21 64 deepens again towards the northwest. The northern basin flat area appears to contain the thickest deposits (>1.0 km), inasmuch as some of the best horizontal reflectors in the basin extend to the deepest zones there (see line 38, Fig. 19). Line 24 in Figure 19 indicates that marginal depressions also border the Emery Seaknoll, and line 21 illustrates the highly irregular folded pre-Recent topography of the area northeast of San Clemente Island (Fig. 20). Basement rock reflections on the Santa Catalina Island Ridge are shown by line 26 in Figure 20, and lines 14 and 21 in Figure 20 indicate that volcanics or similar dense rocks apparently comprise the bulk of San Clemente Island. Age and Origin of the Santa Catalina Ba^sin The major development of the Continental Borderland is believed to have occurred during Miocene time by Shepard and Emery (1941) and Emery (1954 and 1960). Miocene rocks have the widest distribution in the area and phosphorite on the bank tops contains Middle to Late Miocene foraminifera (Emery, 1954). Andesite is reported to be the predominant Miocene volcanic both offshore and onshore (Shelton, 1954). Probably, the Continental Borderland had its inception in the Mesozoic. Apparently, during the Middle Miocene (Jahns, 1954) a major diastrophic event occurred, leaving its imprint in the unconformities prominent along the mar gins of the southern California basins. This major period of diastrophism, occurring in the Middle Miocene, resulted in faulting, folding, and effusion of andesitic lavas. Dur ing this interval the shape of the present-day borderland probably originated. Since the Middle Miocene, deformation and sedimentation continued more or less uninterrupted until the Middle Pleistocene orogeny (Jahns, 1954). The structure of the modern borderland may have origi nated according to the hypothesis of Menard (1960) as a result of the East Pacific Rise Convection Cell which passes under the North American Continent near the Gulf of Califor nia. A brief review of the origin of the Continental Border land is necessary to bring the structure of the Santa Cata lina Basin into focus. Of prime importance is the San Andreas fault system and its sympathetic faults. The San Andreas is an active right lateral fault along which move ment is presently occurring. Activity is believed to have taken place since Jurassic time and a maximum displacement of perhaps as much as 350 miles has taken place (Hill and Diblee, 1953). Significantly, almost every fault in this area which trends parallel to the San Andreas, northwest- southeast, has a right lateral component of displacement. If this trend is carried into the offshore area, then the sea floor of the Pacific Ocean Basin is also moving north west relative to the continental landmass lying to the east of the San Andreas fault zone (Menard, 1964). Although the cause is unknown, various theorists such as the advocators of expansion or contraction must still draw their inferences from the same set of data. Regardless, the Continental Borderland block including the Baja California Peninsula doubtless lies in the eastern one-half of a shear zone caused by movement along the San Andreas fault system (Carey, 1958, Menard, 1960, and Krause, 1961). According to Krause (1961), an east-west dilation exists in the crustal section of the borderland. Because of the funda mental weakness of the earth's crust at the ocean-continent interface, Krause (1961) believed that a tensional east- west expansion of the crust should have a shear component in the right lateral direction of the San Andreas. Further more, Krause (1961) noted that this broad shear zone between the San Andreas fault zone and the deep sea should have a greater northwest displacement of blocks relative to the continental interior rock as one moves westward from the San Andreas fault. Projecting the speculation further, if the Borderland-Peninsular Range-Baja California block is moving northwestward and is abutting against the Transverse Range- North Channel Island complex, as it is indeed doing, then this block is and has been exerting a compressive force upon these transverse structures. As a consequence, one would expect the borderland block to exhibit a more or less east- west structural trend in the surface and subsurface as a response to the compression. Evidently, this is not as apparent in the surface structure as one might eaqpect. Al though the onshore Los Angeles and Ventura Basins and the offshore Santa Barbara Basin do exhibit an east-west trend, it is not as apparent or is not found in the other surface structures of the borderland. Fortunately, Harrison (per sonal communication, 1965) has shown by interpretation of gravity maps that an east-west trend occurs in the basement rock of the Northern Borderland. This, then, leads to an other problem as to why the dominant surficial structures are northwest-southeast trending. Accepting the specula tions of Krause (1961 and 1965), one would expect the rela tively incompetent upper crustal rocks to be modified in response to tensional and shear forces due to the relative movement of the oceanic block to the continental block. As aforementioned, folding and faulting with differential move ment along the faults parallel to and sympathetic with the northwest-southeast trending San Andreas fault system should have evolved, as is apparently the case in the borderland. Thus, on the basis of the geologic and geophysical data, the Santa Catalina Basin appears to have formed during the Mio cene and reflects a complex origin whose present spatial trend may be a result of block faulting, shear, and uneven stretching, although later modified by igneous and meta- morphic processes. RESULTS OF CORES AND DREDGES Core Results Locations of cores are shown in Figure 22 and general station statistics are given in Appendix B. Only the com ponents in the sand size fraction of the 0-3 cm interval of the cores are reported in detail (see section on sediment- ology). This fraction, >0.061 mm, consists of ubiquitous calcareous foraminifera, minor amounts of fine sand, and commonly radiolaria, broken glass rods from siliceous sponges, sponge spicules, and occasionally mica flakes. Diatoms, echinoid fragments, fecal pellets, chitinous mater ial, and glauconite are less common constituents. Phosphor ite, shell debris, ostracods, bryozoa, fish scales and fish teeth were observed in a few instances. The basin slope and basin flat cores consist primarily of land-derived sandy silt and silty clay, with varying amounts of pelagic and benthonic organic material as well as allogenic minerals which are primarily displaced authigenic 69 * 70 H I * ***-•»!» • , V i iM-H« _ „ Wk^nt r! — r in iw i i CORE AND DREDGE SAMPLE LOCATION MAP OF THE SANTA CATALINA BASIN. CALIFORNIA. K*U * I*-- 1 0 * **h It OCNO 114110*1 4M#» ALLAH HlhfOCl fOtftMtlOft. UfclVl«ll1v or tOuH*Ml C4tlf0**>4 « >MVU MHtMCI HIT *141*0*. Hi • U M i Clvti (Hill*** HI, voiHf Hucmivf M - H4M *C 4 0 « I » 0 M .« < • • CMC l U T l t i — • H I M IHfiM lit* 71 glauconite and phosphorite. A few cores contained giant foraminifera which ranged up to greater than 2 mm in dia meter in the surface interval (N0TS-10), whereas others con tained an apparent diminutive fauna (AHF 8424). Some cores, for example AHF 8320, contained graded bedding, layers of sand and silt, and very abundant mica which is suggestive of a displaced shallow water sequence. Other deep basinal cores (AHF 8425) contained shallow water shell debris which may also reflect a displaced unit. In contrast, a few cores consisted entirely of a se quence of monotonous unbedded silty clay with scattered fine-grained angular sediment presumably of aeolian origin (Rex and Goldberg, 1958). Grain by grain settling from suspended sediment, in the water column and within organ isms, and bottom transported sediment by turbidity or nor mal bottom currents probably account for these particles. On the other hand, the origin of the thick sand layers (Plate 4) suggest some sort of a rapid dumping effect such as is believed to be due to a turbidity current mechanism. Sediments obtained from the Emery Seaknoll contain abundant phosphorite, glauconite, and foraminifera. Mottled sediment in AHF core 8692 caused by mud-inhabiting organisms indicate that sediment is mixed after deposition and that 72 B PHOTOGRAPHS OF REPRESENTATIVE CORES OF THE SANTA CATALINA BASIN, CALIFORNIA A - AHF 8320: B - AHF 8321: C - NOTS-6: massive olive green mud massive bluish-gray sand interbedded sand (white), clay (light gray), and clayey silt (dark gray) D - AHF 8691: graded sand layer in olive green mud 73 any original laminations or bedding present have been destroyed (see Plate 4). Interpretation Bottom transported sediment may arrive directly across the sill at the southeast part of the basin if turbidity currents have enough energy to cross the divide between the San Diego Trough and the Santa.Catalina Basin and still possess enough momentum to cross the sill. Of necessity, this implies a source of sediment from the San Gabriel and Santa Ana River systems, presumably in the pre-Recent when sea level was lower. Large landslides and slumping may be a chief contributor of sediment to the basin at present, be cause coarse materials have been found in cores (NOTS-8) from a supposedly muddy basin floor. Also, some material may be reworked coarse elastics from pre-Recent, presumably Miocene and Pliocene (?) rocks exposed on the sea floor. Core NOTS-IO bottomed in a Pliocene (?) sandstone. Some coarse sediment in AHF core 8320 may have come from either the Emery Seaknoll or the San Clemente escarpment. The absence of any major channels in the basin suggests that turbidity currents are now inactive. Any minor recti linear channel-like depressions that do occur, can 74 presumably be interpreted as fault troughs. The southeast ern part of the basin appears to be partially filled by a fan. This probably represents the pre-Recent site of depo sition of "coarse sediments" from the divide area and the finer material has passed into the basin flat areas. During the time of lowered sea level in the Pleisto cene , ranging from 70 m to possibly as much as 1100 m (Kuenen, 1950), much of the sediment of the basin probably came from the islands, ridges, seaknoll, and bank tops. The basin was closed by a low sill at the southeast without any apparent channel-like depressions. The origin of the sill is unknown; however, it may represent a deformational fea ture rather than being of turbidity current origin. A de tailed survey of the sill area has not been made. The presence of sand layers intercalated with basin muds arouses much speculation. Although turbidity currents have been discussed, speculated upon, and experimented with in and out of the laboratory, the concept is not universally accepted because they have not been seen directly. Gorsline and Emery (1959) studied the nearshore basins and indicated that sediment is moving into the basins. They called upon the mechanism of turbidity currents to cause the features observed within the sediment. More recently, Emery (1964) 75 suggested that turbidity currents have been active since the Precambrian time as indicated by textural and structural evidence in the stratigraphic record. According to Menard (1964): The presence of sand layers provides no new line of evidence to support emplacement of turbidity currents. They do, however, give yet another proof that some process transports and sorts sediments on the deep sea floor. Therefore, in the absence of any other known process they sure also tentatively attributed to turbi dity currents. Assuming that turbidity currents exist, then they should be most active in the vicinity of submarine canyons where the beach-canyon-fan cell is likely to be operative. During low stands of sea level in the Pleistocene, when presumably rainfall was greater, more sediment was avail able due to a greater esqposed shelf area and greater river run off. Consequently, with lowered sea level, more avail able sediment, and fluctuations in the surface ocean tem perature causing density gradients, the turbidity mechanism may have been an important contributor of sediments to the basin. Dredge Haul Results Dredge hauls are listed in Appendix D and locations 76 sure shown in Figure 22. Nine dredge hauls were taken from the flanks and tops of the Emery Seaknoll, the east escarp ment of San Clemente Island, and the west escarpment of the northern Santa Catalina Ridge (see Fig. 22). Quartz-albite-chlorite-zoisite schist was dredged from AHF station 8426 along the west escarpment of the northern Santa Catalina Ridge. Sphene and glaucophane (?) are pres ent. This rock is highly contorted, relatively fresh, and i i was dredged from a depth of 910 to 454 m. A thin section photomicrograph of the rock is shown in Plate V. A complex rock of andesitic composition was dredged from AHF station 8420 at the top of the cone-shaped Emery Seaknoll from 130 meters to 121 meters. This rock fragment is the second bit of evidence which indicates that the sea knoll contains igneous rock. Garrison and Takahasi (1950) reported rhyolite occurring on the Emery Seaknoll. Rocks of the andesite-rhyolite clan occur on some of the nearby is lands . Petrographically, the rock is classified as a silici- fied andesite autobreccia, although it may be called an an- desite "tuff." Feldspar phenocrysts are generally angular, fractured and shattered, resorbed, of various sizes, and a few are normally zoned to oscillatory. Extinction angles A B Plate V PHOTOGRAPHS OF THIN SECTIONS OF ANDESITE AUTOBRECCIA (A) AND PHOSPHORITE NODULE (B) DREDGED FROM THE EMERY SEAKNOLL AT A WATER DEPTH OF ABOUT 780 METERS AT 33°02' N LAT., 118°23' W LONG. (A) Andesite autobreccia showing zoned (a) and corroded (b) plagioclase crystals Plagioclase microlites (c) are inset in glass (dark areas) which has been fractured. Crossed polarizing prisms; magnifaction 62 1/2 X. (B) Phosphorite nodule illustrating irregular layering (a), numerous foraminifera (b), ellipsoidal phosphorite (c), and some glauconite fragments (D). Crossed polar izing prisms; magnification 6 1/4 X. indicate that the feldspar is at the upper range of andesine composition. Extinction angles on microlites in the glassy groundmass (pilotaxitic texture) of the autoliths appear to have a more sodic composition and lie within the composition range of oligoclase. Orthopyroxene and augite are the domi nant mafics and "iron ore" is also present. Iron staining is prevalent on the highly oxidized margins of the rock. A semiquantitative spectrochemical analysis is listed in Table 2. The writer suggests the rock represents the outer rind of an andesite pillow flow because of the monolithologic fragments which appear to have been once connected, the presence of glass and shattered crystals and rock which sug gests a rapid change in temperature conditions. Rhyolites and andesites are present on San Clemente Island and the rocks of the Emery Seaknol] may be consanguineous with them. According to Williams, Turner, and Gilbert (1954), basic andesites generally form thick, short flows or steep-sided domical protrusions, both of which may be present on the Emery Seaknoll. Shelton (1954) concluded that the main volcanic episode in the Los Angeles area was in Middle Mio cene timer Olmsted (1958) dated the andesites and rhyolites of nearby San Clemente Island as of probable Middle Miocene 79 TABLE 2 SEMIQUANTITATIVE SPECTROCHEMICAL ANALYSES OF DREDGED ROCKS FROM THE SANTA CATALINA BASIN, CALIFORNIA Element Station AHF 8420 Station N0TS-14 Silicon 24.0% 1.3% Calcium 2.3 22.0 Aluminum 10.0 1.3 Iron 10.0 1.1 Magnesium 2.3 2.9 Sodium 1.7 1.2 Phosphorus nil 19.0 Barium nil nil Boron 0.0065 0.029 Titanium 0*82 0.019 Manganese 0.084 0.036 Lead nil 0.097 Gallium 0.0059 nil Chromium 0.019 0.030 Nickel 0.0084 0.022 Vanadium 0.029 0.013 Copper 0.0031 0.0030 Zirconium 0.018 nil Cobalt 0.0080 nil Strontium 0.012 0.16 Potassium nil nil Other elements nil nil 80 age; Kemnitzer (1933) dated the "basalts" on Santa Barbara Island as Middle Miocene. Tentatively, the volcanic rocks of the Emery Seaknoll are considered to be of a similar Mid dle Miocene age, which, in turn, may also date the apparent time of formation of this structure. Phosphorite is the chief constituent of the dredge hauls on the Emery Seaknoll. It is usually dark-colored although light-colored phosphorite nodules were also found in the dredge, suggesting possibly two major periods of phosphorite formation (Emery, 1960). Typically, the nodules and grains sure hsurd, dense, have a smooth glazed brown sur face, and often sure encrusted on the exposed surface with organisms such as worm tubes, bryozoans, sponges, and cor als, indicating that the nodules sure in a low energy envir onment . A semiquantitative spectrochemical analysis for AHF station 8420 is listed in Table 2 and a photomicrograph of a thin section of a phosphorite nodule from AHF 8420 is shown in Plate V. Petrographic analysis of samples from AHF 8420 re vealed that the phoshporite nodules are primarily collo- phane, a nearly isotropic microcrystalline mineral. Some anisotropic material showed a banded and fibrous texture 81 which may be either dahlite or francolite. Similar minerals have been observed in phosphorite nodules by Dietz, Emery, and Shepard (1942) and Emery and Dietz (1950). These miner als usually form small ellipsoidal disseminated grains, oolite layers, and replacement of originally calcareous mollusc shells and foraminiferal tests. Small disseminated grains of clastic minerals, such as feldspar, quartz, mica, and pyroxene (?) are present. Some grains are rounded al though most are angular. Photomicrographs showed irregular and regular layering, suggesting that discontinuous and con tinuous periods of accretion occurred, respectively. Grains, pellets, and casts of foraminiferal tests of glau conite also occur as segregations or disseminated throughout the nodules. The age of phosphorite nodules in the Borderland is divided into two groups, the dark-brown nodules which are Middle to early Late Miocene and the light-brown nodules which are Pliocene to Recent (Emery, 1960). According to Emery (1960), the occurrence of phosphorite is common to the shallow areas of the Northern Borderland, whereas Krause (196i) has shown phosphorite to be uncommon in the Southern Borderland. The paucity of phosphorite nodules in the Southern Borderland is believed to be due to the greater 82 depth in that area (Krause, 1961), The part that the structural highs of supposed pre- Cretaceous rocks at Santa Catalina Island, Santa Barbara Island, and San Clemente Island may have played in the depo- sitional history of the younger sedimentary rocks in the region is unknown. Dredging and coring in the basin, how ever, have yielded clastic fragments of basement rocks simi lar to those on Santa Catalina, Santa Barbara, and San Cle mente Islands. Also, terrace gravels on these islands con tain glaucophane schist, suggesting a nearby source for this rock type. Whether or not these schist fragments were de rived from a sedimentary formation resembling the San Onofre Breccia of Middle Miocene age that may be concealed on the sea floor near the islands or from old structural highs of Sodium-Amphibole schists is conjectural. BOTTOM PHOTOGRAPHY Bottom photographs of the sea floor were obtained from several locations, although most were near the eastern es carpment of San Clemente Island. They were taken and made available by Mr. Frank Strahalm of the United States Naval Ordnance Test Station, Pasadena. He obtained them with a new and improved Edgerton deep sea camera and pinger. The sea floor of the Santa Catalina Basin has areas which sure covered with tracks of animals (see Fig^ 23). These sure probsfely echinoids and holothurians and include sea cucumbers, urchins, ophiurods, worms, sea pens, brachio- pods and others. Where organisms sure absent in the photo graphs, tracks sure usually present, indicating that they may cover a great deal of the sea floor. Unidentifis&le fea tures reveal that possibly other organisms are living in and on the surface sediments. Fish sure present in the photographs suround the east flank of San Clemente Island and appsurently rest on the sea 83 FIGURE 23 BOTTOM PHOTOGRAPHS OF THE SAN CLEMENTE SLOPE AT A WATER DEPTH OF ABOUT 800 METERS AT 33°01* N LAT., 118°31' W LONG. Photographs courtesy of F Strahalm, United States Naval Ordnance Test Station, Pasadena, California (A) Sea Pen (a), Sebastolobus ? (b), urchins (c), uniden tified trials (d), and irregular microrelief (e). (B) School of Sablefish (a), on and above the bottom, starfish (b), and numerous urchins (c). 85 floor, a condition which may cause bottom irregularities. Where photographs show living organisms, the distribution pattern of the biomass can be estimated. Photographs indi- cate a distribution of about 1/100 square meters and 10/5 square meter (see Fig. 23). Some of these animals are pri marily .mid-ingesting and indicate that the surface sediments to an unknown depth in the sea floor are in a dynamic physi cal and chemical environment which is in a constant state of change. The effect in the sedimentary record is obvious and adds to the understanding and explanation of some of the monotonous unbedded sequences (see Fig. 23) common in cores. X-RADIOGRAPHY Latent structures in apparently homogeneous sediments were resolved using the X-radiographic techniques of Hamblin (1962) and Calvert and Veevers (1962). Exposures were made on Kodak Type M Industrial Film using a Picker-Harding 3- phase X-ray unit. X-radiographs of representative features of cores sure shown in Figure 24. The X-radiograph technique confirmed the homogeneity of sediments that appeared homogeneous in reflected light, and resolved in finer detail structures which were already apparent in reflected light. In addi tion, they revealed discrete particles, such as organisms and sand balls, which lie beneath the surface of the sec tion, and revealed latent structures, such as bedding and mottling, which were not visible in reflected light. 86 A-l A-2 B-l B-2 C - l 02 D - l D*-2 FIGURE 24 X-RADIOGRAPH SECTIONS (LEFT PHOTOS) AND PHOTOGRAPHS (RIGHT PHOTOS) OF REPRESENTATIVE CORES OF THE SANTA CATALINA BASIN, CALIFORNIA A-I NOTS-8: B-l NOTS-17: C-l NOTS-18: D-l NOTS-11: radiograph shewing indistinct mottling and irregular laminae; photograph A-2 appears homogenous radiograph showing distinct mottles; photo graph B-2 appears homogenous radiograph reveals a sand ball and distinct laminations; photograph C-2 exhibits faint laminations radiograph showing distinct laminations and apparent cross-laminations; photograph D-2 exhibits indistinct streaks -.. - SEDIMENTOLOGY General Statement The purpose of the sedlmen to logical study was not only to determine and map the areal distribution of the surface sediment parameters on the basinal sea floor but also to discover the processes that may have caused their deposi tion. Horizontal correlation studies of this type within a single basin of deposition may bring out trends or varia tions applicable to stratigraphy. All surface sediment samples were analyzed texturally, chemically, and mineralo- gically. Detrital grains, both bottom transported and pelagic, benthonic and planktonic organics, and some authi- genic sediments (really allogenic because they are displaced or reworked) greatly influenced the size analyses of the stir face sediment. Size Analyses Standard sieve-pipette methods (Krumbein and Pettijohn, 88 89 1938) were used in the mechanical analysis of the 0-3 cm surface interval. Some modifications, however, were used because of flocculation even after three to five filtra- tions with distilled water and Calgon diapersant. in order to oxidize the organic matter in some samples, about 100- 150 ml of 30 per cent was added to a 5 gm sample. Samples which still flocculated were dried, treated with acetone, dispersed with a sodium oxalate-carbonate peptizer, reprocessed with HqOq, and filtered several more times. The coarse fraction was analyzed using the techniques of Shepard and Moore (1954 and 1960). Approximately 100 grains from each Wentworth sand-size fraction were counted using a grid system with a binocular microscope. It should be noted that the composition of the surface sediments (top few cm) are composite in nature and reflect both the present depositional conditions and also earlier depositional conditions. No laminations were apparent in the cores under the binocular microscope and the surface sample represents non-laminated homogeneous mixed sediments. Textural data were analyzed statistically with the aid of a Honeywell 800 computer. Momental values for mean grain size, standard deviation, skewness, and kurtosis are listed in Table 3. J ■ ■ “ " ---- CPPt 14 * 1 M ’ P M ’ O Of CO act •'t>: OOOWO vutn I'M I’M CP M ’ O- 4 CP- IP‘ 1 1100*0 •ca P’a i-oni •*•* C M CP M ’ O- M'P U ’l 1 *00*0 tO' 4 Cl •-mi O’M C M Cl 10*1- 40*0 •0*1 MOO'O ’ M ' 4 ••• c^taaa r n I'M C‘ « aca •1*1- ta*a 4100*0 Ct'O ca a-'nao t'» I’ tl •*• M*t- M ’ P- tea 1*00*0 00*4 - a*» t-aaao *— *'M H'l M ’ O •4*0 M ’t 10* 0- 0*0011 t-*CII — — — - C M W'O- aco- •ft 01*1 •1* 0- O'tTO •-•«•« -— C M M't •4* 0- 44*0 •aco aci 0*001 l-’ C* I’M I’ll 4 C 0- W*0- M ’ t •000*0 Pl‘ 4 •*4 PI 0400 »'N C M P’l M*0* ao'o •0*1 MOO'O CC4 • *• Ml MOO I'M t’ M P’l • ICO* 10*0- 44 * 1 MOO'O M ’t c* M 0400 C M CPI I’t M ’ P* wo- •4*1 0100*0 PC 4 I'I 4 1 ora •‘•I CPC l’ PI ICO* •1*0 w a 410*0 •4** 0*80 M OIOU C M cia C M M'O* ICO M'C •M’O M*» 0*CP •1 0400 »*» •’ Cl CP aco* •1*0- M ’t MOO’ O 00’ 4 •’• 11 MOB t'TI C M C M M't- 40* 0- ICC MO’ O U't 0*00 01 0400 C M C M C M M*0- M*l M*a •M’ O 4 *** 0*1 * P 0401 t'tt C M C M M'P- ta*p- aca M 0‘ 0 It’* 0*M • 0400 I’ll •’ •4 -O’* M'O- aop- 40*1 •00*0 00*4 0**1 4 OMR I’M C M I’t 0**0- M ’ O IC1 0400*0 M ‘ 4 0*0 • 0400 I’ll C 4 * Cl 4 P*0- M ’ P 4 4 *1 MOO’O ••’• C M I 1400 •’ 11 cc» ■‘IP PC’ P* M'O to'a OCO'O •O’I 0‘M av-oioo r m C M Ct M ’ P* •CO- OO’I MOO’ O aca 0*1 1-0-0 «*1C I'll a*4 i 11*1 - PI’ 0 •4‘a •MO’ O aco o*n a-o-o •’1C •’Cl I’M W ’ O- 11*0 n*a MOO’O *4’ » a*4 i 1-0-0 •••* P’M ca M*l- oa*o- oca 0*00*0 14*4 •** •PM JW •*• I’ l cap M ’P IP’ O M ’t 000*0 M ’l • *M0 1 PM M »'R C M 4’M M ’T- oa*o M*a MO'O M ’* CPI o pm on 1*4 *’ • 1 I’M *1 * 1 CP'l oo*a MO’ O 40*1 O'POl M M on «’» 4’CP C M ■P’ O* M ’O- •ca 0000*0 •1*4 0’» M M on I’M 4*11 •’ * H ’l- M ’O- •a* a 0000*0 00*4 •*• 4 IM JW C M C M C M . M ’ P- •0*0 •ca 0110*0 ao‘« 0*01 M M in C M •*n P'M aa’ p 4 C 1 •»*a 0*40*0 •c* O'Ml ISM JW •*M C M •‘M •CO- M ’ O ••*a 0410*0 t*'• •‘•a M M JW •'» C M I’ l fp’ p- •1*0- ao*a •MO'O M ‘ 4 i'i M M JW I’M 4'M a** aca* aco- M*a •MO’ O 14*4 Cl •8M JW Cf* I’ M t’i •4* 0- ICO- •4‘t MOO’O ••'4 •*• M M JW l’i I’ M •’4* M ’ a M ’l M'l IM’ O M** O’M M M JW CPI 4‘ M C 4P Cl* 4**0 M ’f 00C 0 tea 0*111 taw j w ••« •'• P’PP OI'I . ao’i IP‘ 1 oaa'o •t*a 0*040 OOM JW ca I’l cap PP'« •Cl fl’l OM'O OP’l 0*001 P1M JW •‘H •’4 * Cl *4*0- PCO- co’ a MOO'O w a P'l M M JW CM. f «4 •*a aco* M'O «o*a 110*0 0C’« **01 tato j w C M I’ll ca oco- 1C 0- oi*a •MO'O 10*4 a‘t •aca j w *’4 * 4‘ M •*a 4 P’ 0- M'P- oo*a •MO’O 1C 4 •*• •1(0 JW C M C M i'i M ’ P* 0C 0- M*a 0*00*0 M ' 4 •*( 41 M JW C M CIP Cl M'O ' 04*0- •4 * 1 MOO’ O . M'O 0*1 •tea j w C M C M CP IP’ t* Ct’0- ip* i 1*00*0 M ' 4 C* M M JW C M 4*4 * I’ll 14* 0- • •‘ 0 M ‘l MO’O OP‘I O'PO •ICO JW ura m m ire vim au jo iwawi (a i-o) soumm so uniaw ii wi m 9 1 The results of the analyses for surface samples are illustrated as cumulative curves on arithmetic probability paper (Fig. 25) and also as frequency curves and histograms on arithmetic paper (Fig. 26). Comparison of the cumulative curves of sediments from the Santa Catalina Basin indicate that two main groups of size frequency distribution can be distinguished on the basis of curve shapes. Representatives of each group are shown in Figure 25. No attempt has been made to relate textural parameters to the hydrodynamics of the basin because energy factors such as bottom current measurements are lacking. Conse quently, any speculation regarding the hydrodynamic effect might be misleading. A study of currents at variable depths is currently being made in the basin, but no data are now available. Texture Sediment type Unconsolidated sediments in the Santa Catalina Basin consist of grains that range in maximum diameter from less than 1 micron to greater than several millimeters. The CUMULATIVE PERCENT 99.5 5 0 .0 - 100- 0.50 NOTS G-l NOTS G*2 NOTS 5 1 NOTS 9 9 .5 9 0 .0 - 5 0 .0 - 1 0 . 0 - 0 .5 0 NOTS G-3 NOTS 4B NOTS 7 NOTS 99.5 9 0 .0 - 1 0 . 0 - 0 .5 0 AHF 8418 AHF 8419 AHF 8422 AHF ( 9 9 .5 9 0 . 0 - 5 0 0 - 100- 0.50 I 0 5 1 0 MEAN D IAM ETER + U N ITS AHF 8420 O 5 1 0 AHF 8421 O 5 0 AHF 8424 AHF 8 PROB NOTS 6 NOTS 6 NOTS 9 NOTS 10 NOTS 16 NOTS II NOTS 15 / NOTS 16 AHF 6423 o 9 AHF 6425 to AHF 8426 O 5 AHF 6686T AHF 6685 AHF 8687 AHF 8 68 6 5 0 . PRO BABILITY AHF S690 C U M U L A T IV E CURVES FOR SANTA NOTS 16 NOTS 17 NOTS 19 AHF 8314 NOTS I8A NOTS 18 AHF 8315 AHF 8316 LITTLE HARBOR AHF 8692 AHF 8 6 8 9 AHF 8686 1 0 5 0 0 5 1 0 1 0 5 0 0 5 1 0 AHF 8690 AHF 8691 MA-I M A - 2 SANTA CATALINA B A SIN AREA SURFACE SEDIMENTS 92 AHF 8319 AHF 8314 AHF 6317 AHF 8321 AHF 8316 AHF 8320 NCEL 4 NCEL I M A -3 rTLE HARBOR 5 0 1 0 0 5 1 0 1 0 5 M A - 2 NCEL 2 NCEL 3 NCEL 5 MENTS FIGURE 25 CUMULATIVE PERCENT 100 50- NOTS 6-1 NOTS 6-2 NOTS 6-3 100 50- / l p s . NOTS 4B NOTS 5 NOTS 6 100 50- NOTS 7 NOTS 8 | a a 50- I I NOTS 9 MEAN DIAMETER t NOTS II NOTS 10 5 I I NOTS IS FREQUENCY I 6-3 NOTS 16 NOTS 17 NOTS 16 AH /V-, 6 NOTS ISA NOTS 19 AHF 6914 A M .___ J \ 9 AHF 6SI5A AHF 83I6A AHF 6917 Al / i II 15 i 1 3 1 AHF 6310 1 3 1 AHF 9920 I - 1 3 1 AHF 6921 1 1 Al ENCY POLYGONS AND HISTOGRAMS FOR SANl AHF 6414 AHF 8419 AHF 6688 AHF8420 AH A J AHF 6422 A H F 8691-C AHF 6421 AHF 8423 AHF 6424A AHF 8426 MA-I AHF 6425 AHF 8667 NCEL I AHF 8685 AHF 66MT SANTA CATALINA BASIN AREA SURFACE SEDIMEN* 93 HF 8686 AHF 8689 AHF 8690 \ H F 8691-C M A-I AHF 8692 MA-2 II NCEL 2 NCEL I LITTLE H A R B O R MA-3 NCEL 4 I I - I 5 I I - I NCEL 3 5 I I NCEL 5 E SEDIMENTS FIGURE 24 94 standard Wentworth nomenclature for size classification is used (Wentworth, 1922). Because sediment samples may contain varying percent ages of sand, silt, and clay, a triangular size-composition diagram can be used to classify sediment types. The trian gular diagram (Fig. 27) is modified from Shepard (1954) and consists of a three component system which is divided into sediment types according to the percentage composition of the three representative sizes. A perusal of Figure 27 indicates that although there is a complete spectrum from almost 100 per cent sand to silty clay, the dominant mode is in the clayey silt range. Clayey silt comprises about 45 per cent of the basin sediment, with silty clay ranking second with 16 per cent. Sand-silt-clay and silty sand each comprise 14 per cent of the types. About 11 per cent of the sediment type is sand, of which 5 per cent is from Osborn Bank and the remainder from the basin floor. Due to the low density of sample sites it did not seem prudent to contour isopleths of sediment type. However, percentages of sand, silt, and clay are plotted on sector diagrams for each sample locality (Fig. 28). It is apparent from Figure 28 that the sands are associated with areas of 95 CLAY CLAYEY CLAY CLAY CLAY SAND- < v o SILT - • • • CLAY 20- SILTV SAND 50 CLAYEY TEXTURAL TRIANGULAR COMPOSITION DIAGRAM OF SANTA CATALINA BASIN SEDIMENTS Modified from Shepard (1954) B ated on Sand ( 2 -0 .6 2 m m ), S ilt ( 0 . 6 2 - 0 .0 0 4 m m ) , Clay ((0 .0 0 4 m m ) FIGURE 2 7 V 96 I I A * * * -I—,"— * % € ) © «o tor uf SECTOR DIAGRAM FOR THE PERCENT OF SAND. SILT. AND CLAY IN THE SURFACE INTERVAL 0 - 3 e m OF THE SANTA CATALINA BASIN. CALIFORNIA FtGUftE 2ft 9 7 elevation such as Santa Catalina Island, San Clemente Island, the Emery Seaknoll, and the high area at the southern margin of the basin. Silts are dominant along the Catalina Fan and clays are important in the basin flats. Mean diameter The distribution of mean grain sizes in the basin apparently is correlative with sediment type. Values for mean diameters sure tablulated in Table 3 and shown in Figure 29. Mean diameters within the basin range from 0.003-0.300 mm. A high mean diameter of 0.260 mm was found on the Emery Seaknoll; however, the highest value of 1.18 mm occurs on Osborn Bank. In general, the mean grain size decreases towards the deeper portions of the basin. Median diameters obtained graphically from probability curves and computed by the method of moments are in vari ance. This discrepancy is partially a reflection of the polymodal (multisource) character of some of the curves. Hence, the median diameter parameter does not always accur ately describe sediment size. As might be expected in a basin environment, the median diameters decrease with increasing depth (Fig. 30) and the lowest value of 0.003 mm is in one of the deepest parts of 98 to' MMV* MM*** 0 »M ta . If'Sr MM l.M * * IIL -9. 1 * mm V ^ \ \ v tt MA'IV L « X l . M — m — nr ■IH ■IN am - > . # • I- * * S ’ # -r« i t a M — • If ® j s r i t •mi *y* t * « # ^ ‘S v i ! F r J # In, mm 22, •«U lk -8T M-» .(« ___ ** jg, K it K I ® i t aT • LtttMD •ti*M MM Ml fTMMN tnim MITMMTIC MM (MMHM NtMIMW ----Y^X.fU CM IM X ^ g i ■ra. fff f f i . " i t MU’ S # • 0I5TANCE DISTRIBUTION OF STANDARO DEVIATION, ARITHMETIC MEAN, SKEWNESS, AND KURTOSIS OF THE SANTA CATALINA BASIN, CALIFORNIA nw»i»» 500- C0 a: ui 2 1000- X H Q. UJ o 1500- 2000- 99 I 10 \ 100 1000 MEDIAN DIAM ETER p UNITS R E L A T IO N S H IP BETW EEN M EOIAN DIAM ETER AND DEPTH IN THE SANTA C A T A L IN A BASIN FIGURE 30 1 0 0 the basin. Standard deviation Sorting, the measure of dispersion or scatter about the mean, can be measured by various methods. In this study momental standard deviation in phi units is used (Table 3, Fig. 29). However, for comparison with earlier studies in the area, the Trask Sorting Coefficient has been plotted against median diameter (Fig. 31) and is also listed for each station (Fig. 29). The range in standard deviation over the whole area is 0.77 ^ on Osborn Bank to 3.92 <p along the San Clemente escarpment. Basin flats range from 1.71 to 2.21 ^ and average about 2.02 < f > . Various classifications have been proposed for the degree of sorting in phi units such as Folk's (1961). His classification lists standard deviations from 0.00*0.50 phi units as well-sorted sediments, moderately-sorted from 0.50- 1.00, poorly-sorted 1.00-2.00, and very poorly-sorted if greater than 2.00. A study by Emery (1954) of the average sediment parameters for various environments indicated that the degree of sorting is meaningful only within a restricted geographic area. Therefore, any classification of the de gree of sorting is relative only in terms of other samples 101 1000 100- 3L 10- V# ••• •% I TRASK SORTING CO EFFICIENT RELATIONSHIP BETWEEN MEDIAN DIAMETER AND TRASK SORTING COEFFICIENT OF SURFACE SEDIMENTS FIGURE 91 102 within the area of study. A broad, apparently sinusoidal trend exists between the mean grain size and standard deviation due to the wide range of grain sizes (Fig. 32). Similar trends exist for some aqueous environments (Folk, 1960, and Hubert, 1964). This sinusoidal relationship is apparently due to a multi-modal source (Hubert, 1964). Inman (1949) noted that the best sorting occurs in sediments with medians in the fine sand range and poor sorting occurs as mean diameters differ from 0.18 mm. This central V-shaped distribution of the sinus oidal curve is shown in the main trend line in Figure 32 and is known to be typical of most marine environments of deposition. In the over-all basinal environment, the best sorting generally occurs as the mean diameters increase and decrease from Inman's 0.18 mm optimum point, that is, more or less midway between modal diameters. Comparison of Trask Sorting Coefficient (SQ) for ap proximately 50 samples of this study with that of Emery's (1960) data is amazingly close. Emery's analyses based upon 35 samples had an average SQ of 3.7 while 3.76 was the average for the basin floor samples of this study. Because the Trask coefficient measures only the sorting in the central part of the curve and ignores the areas where the o ■n </> c z ■n > o m o> m o m co 3 « c x m IX r \ > S TA N D A R D D E V IA T IO N 6 U N IT S l 2 3 4 -I-------1 ------1------1 ---- CO x H m > i “ z > O -I > o 3 5 O | m tj < > O H ^ ° Z z ™ rn > z o > z m H m z > z o CO X m € z m co co I f 15 i ! HI • SILTY-CLAY CLAYEY-SILT -SILT-CLAY CO k -h e ir iu h hJ 2 < O s + * Eiem Cootm' SKEW NESS 6 UNITS -I 0 1 2 J I I ____— L >• ■ 1 0 < So Etc*** F i r . * < o - - 4- a z " l i If s*i5!|!*-! — ■ i*l v: • • • • • • ■m • 104 differences between samples are most marked, the ends or tails of the curve, its use is questionable. Consequently, the standard deviation as obtained from the method of mom ents is used since it is considered to be more representa tive of the true sorting because every grain in the system affects the measure. Inasmuch as the finest grain sizes were probably de posited in a flocculated state, it is not certain what the actual size-sorting or size-skewness relationships are in the fine sediments because analyses were run on defloccu lated samples. This indicates that the values obtained may bear little resemblance to the original size distribution. Detailed studies of suspended sediment are needed to clarify this matter and an initial survey has been made by Rodolfo (1964). Also, it would be interesting to determine whether the flocculation is primarily in the water column or at the sediment-water interface. Skewness Skewness is a measure of the asymmetry of a curve and indicates the presence of small amounts of fine or coarse grains at the tail of the curve. Curves with excess coarse material have negative skewness and those with excess fine material have a positive skewness. Multiple source areas may be indicated by skewness measurements. Momenta 1 skew- ness values are listed in Table 3. Areal distribution of momental skewness in the Santa Catalina Basin is shown in Figure 29. About 45 per cent of the samples on the basin floor have weakly negative skewness (0.00-0.50^) which indicates a slight surplus of coarse material. Approximately 10 per cent are nearly symmetrical. Of the remaining 45 per cent of the basin samples, 55 per cent are weakly positive-skewed and 45 per cent are strongly positive-skewed, possibly as the effect of deflocculation. Sediments apparently emanating from the San Gabriel Canyon System are nearly symmetrical with values ranging from -0.09 to +0.02, whereas those along the Catalina Fan have appreciably higher positive and negative values. The abun dance of skewed values both left and right within the basin suggests multiple origins for the sediments. A predominance of negative values in the basin flats indicates that small quantities of coarse-grained materal are being added to an otherwise normal fine-grained sediment distribution. This surplus of coarse material probably reflects biogenous com ponents, aeolian terrigenous material, displaced sediments, and possible reworked pre-Recent sediments. 106 Comparison of mean size versus skewness_indicates a roughly sinusoidal relationship similar to mean size versus standard deviation (Fig. 32). This similarity of curves is characteristic of multimodal sediments, and skewness is very closely a function of grain size (Folk and Ward, 1957). In general, skewness is seen to increase negatively from 8 to 6 $ and positively from 6 $ to about 2 ^ where values to -1 are strongly skewed both in a positive and negative manner. The fine to very coarse sands show the greatest scatter ranging from strongly coarse-skewed to strongly fine-skewed. Silty-sand sediments types are extremely fine- skewed, whereas the silty clays are strongly coarse-skewed. Clayey-silt sediment types distributions approach near- symmetrical. In terms of environment of deposition, one might expect the basin flat sediments to be generally near- symmetrical to coarse-skewed, which indeed they are, because of the admixture of biogenous and terrigenous components in the coarser silts and finer sand grades. Kurtosis Kurtosis is the quantitative measure of the flatness or peakedness of a curve and describes the departure from nor mality of a normal Gaussian probability curve. Therefore, 107 kurtosis measures the ratio between the sorting in the tails and the sorting in the central portion of the curve, or it may be thought of as the ratio of the average spread in the tails (Inman, 1952). Excessively peaked curves indicate that the central portion is better sorted than the tails. Flat-peaked or platykurtic curves indicate that the tails are better sorted than the central portion. Mesokurtic curves approach normal kurtosis, that is, a nearly straight line on a probability graph. Values for the fourth moment measure are listed in Table 3 and shown in Figure 29. The majority of the curves in the basin are leptokurtic. Plots of kurtosis against mean diameter do not exhibit the apparent sinusoidal curve found in the standard devia tion and skewness plots (Fig. 32). The kurtosis versus median diameter diagram (Fig. 33) indicates that the finer grades are chiefly moderately leptokurtic, whereas the coarser grades (sands) exhibit a broad spread from meso kurtic to extremely platykurtic. A scatter diagram of skewness against kurtosis (Fig. 34) shows that in general there is a major grouping of nega tively-skewed leptokurtic values and a gentle, more or less linear spread of some positively-skewed points +1 and +2 108 • Crm 1 ; CD 1 < 0 I X N X S 1 IN 0 $ 8 3 1 3 W V IQ N V 3 W * v .. •j *. ' ; V * - • « i -------1 ------ 1 -------1 -------1 ------ RELATIONSHIP OF MEAN DIAMETER vs STANDARD DEVIATION AND KURTOSIS OF SURFACE SEDIMENTS r - t o < / > £• •Z 3 M < 7 > N O h> 2 3 * — O < / ) - o — C V J > Ui O 2 < O z < I- FIGURE 33 KUR TOSIS -2 2- </> -I- -2 RELATIONSHIP BETWEEN SKEWNESS* AND KURTOSIS OF SURFACE SEDIMENTS FIGURE 34 110 from about 0 to 7 kurtosis units. The extreme high and low values imply that part of the sediment may have achieved its sorting elsewhere in a high energy environment and that it was transported essentially with its size characteristics unmodified to the present site of deposition (Folk, 1957). Coarse Fraction Analyses Analysis of the coarse fraction— sediment with diameter greater than 62 microns— is a useful method of establishing trends in sediments between and within sedimentary environ ments. Although not a highly accurate method, differences and similarities are established. A method modified after the technique of Shepard and Moore (1954 and 1960) provided reasonable results. These results are tabulated in Table 4 and variation diagrams across three representative cross sections along the basin are given in Figures 35, 36, and 37. In general, the terrigenous components are greater than the biogenous constituents. However, in some of the finest and coarsest grades, the biogenous components are more abun dant . Mica shows much variation in relation to the total percentage of sand in the sample, but is most abundant where " I 8 1 K I ii i m 4 1 S t. ii f t ■ b i i 1* li r X I MO m 1 8 9 3 8 • f t ft 4 «IS f t f t f t f t i r i ft ft ft ft • • • • 8 S 8 8 • • — « ft ft ~ r ft s s s 8 - ft ft « « ft ft • « • • • 8 « * • * 8 8 8 • • • < • • * ! a a 8 s • * - •* * s - 8 * :•** sun*-;! i l i i s i i i H i i i i i i i S i i i i i : ! i i i i i i n i i i n i i n i i n n n i i i •.11 i ‘ f t f t ! .'i f t f t f t S 9 * • • • • f t f t f t tttt iii a a 9ft«#*ftft333«l**9$ s«a8*«Xis2s liiKiiiSSEEEi illiliEEEEi f t . 1 2:222 Mil! i i i i .tn 9 8 8 8 8 8 8 3 3 ftftftftftftftftft ft*«ftft«|ftftfta| c::stn«3} iniMisiS f t f t f t 3 8 9 3 3 I 8 * NE Not* 4B SS ° Not* 7 Not* 6 I QUARTZ 8 FE LD S P A R VARIATION OF COMPOSITION FOR THE SURFACE INTERVAL OF THE 0 .2 5 -0 .0 6 1 mm FRACTION OF A S W -N E CROSS SECTION OF THE SANTA CATALINA BASIN, CALIFORNIA FIGURE 35 8 ? * S S NOUISOJNOO JO 1N30M3J SAUVinwrtO VARIATION OF COMPOSITION FOR THE SURFACE INTERVAL OF THE 0 .2 9 -0.061m m FRACTION OF A N W -S E CROSS SECTION OF THE SANTA CATALINA BASIN, CALIFORNIA ______________ FIOUW E 36 8 I I 114 8 S 8 8 S 8 8 8 N O U ttO d M O O dO lN30d3d 3All¥inwnO VARIATION OF COMPOSITION FOR THE SURFACE INTERVAL OF THE 0 .2 5 - 0.061mm FRACTION OF A SW-NE CROSS SECTION OF THE SANTA CATALINA BASIN. CALIFORNIA FlOUftC 37 115 the sand percentage is lowest (Fig. 38). A scatter diagram for mica, foraminifera, and radiolarians plotted against percentage of sand is given in Figure 38. Radiolarians oc cur in the greatest abundance where the percentage of sand is lowest. Paralleling the radiolarian trend, diatoms are most abundant in the lowest sand values. In contrast to the radiolarians and diatoms, foraminifera increase in abundance with both increasing and decreasing percentages of sand from about the 40 per cent sand interval. Variations of composition of the 0.06-0.25 mm fractions for three representative cross-sections in the basin (Figs. 35, 36, and 37) indicate the ubiquity of the foraminifera and mica, the association of phosphorite and glauconite with surrounding high areas, and also show that bottom-dwelling organisms are mixing the surface sediments as evidenced by abundant fecal pellets. Roundness values for the 0.25 to 0.063 mm fractions based upon the Power's Scale of Roundness range from 0.5 to 3.5 and average 1.8. Therefore, the fine sands are domi nantly angular. 116 PERCENT M IC A ft RADIOLARIANS 20 100 0 MICA • RADIOLARIANS 1 FORAMINIFERA 00- CHIEFLY 0ENTHONIC FORAMS •o 70- t 50- o* oi FORAMINIFERA 40- 30- CHIEFLY PLANKTONIC FORAMS 20- 10- RAOIOL ARIANS ii 100 50 PERCENT FO RA M INIFER A RELATIONSHIP OF PERCENT TOTAL SAND vs PERCENT OF MICA, FORAMINIFERA AND RADIOLARIANS OF THE SURFACE SEDIMENTS FIGURE 38 MINERALOGY OF SEDIMENTS General Statement Heavy and light minerals from the 0.125-0.62 mm frac tion of the 0-3 cm surface mud interval were analyzed in order to ascertain what mineral sands were being deposited, if any, and their source area. Although sediments cure a product of transport, environment of deposition, and prove nance, their composition is also modified between source rocks and depositional site by weathering of unstable miner als and of selective sorting during transport. Ideally, the entire sand fraction should be analyzed; however, as the finer sands analyzed in this report were generally the most plentiful sand grade and appeared representative of the mode, they were considered indicative of recent sedimenta tion. Consequently, the aforementioned factors controlling sediments may have affected the finer sand assemblages present, but not to any marked extent to discredit their applicability to horizontal correlation within the basin. 117 118 Also, the abundant presence of relatively low stability minerals such as pyroxene and hornblende is indicative that the sediments reflect a first cycle deposit and little modi fication from source to depositional site has occurred. Heavy Minerals Heavy minerals were examined to determine the suites present, their source, and possible method of introduction to the basin. In order to obtain a representative picture of the area, approximately 50 samples were studied. Heavy minerals (>s.g. 2.96) from samples treated with HgOg to remove the organic matter were separated from the finest sand grade (0.125-0.062 mm) with tetrabromoethane, weighed, and expressed as a weight per cent for the grade. Both heavy minerals and light minerals were identified optically using immersion oils and mounted sections. Most of the samples contained sufficient heavy minerals to carry out a normal count. The counts (Table 5) were expressed directly in fre quency numbers which can be equated to per cent or propor tion (Evans, Hayman and Majeed, 1934). Mica, primarily biotite, was present in both the heavy and light fractions as a result of its variable specific 119 TABLE 5 COMPARISON TABLE OF PERCENTAGE, FREQUENCY NUMBER AND PROPORTION ANALYSES NOMENCLATURE Percentage Frequency Nuniber Proportion 80 8 Very abundant 40 7 Abundant 20 6 Fairly abundant 10 5 Very common 5 4 Common 2-3 3 Fairly common 1-2 2 Scarce 1/2-1 1 Rare 0-1/2 1 One grain per slide 0 0 Absent 1 2 0 gravity. Both biotite and opaque minerals have been includ ed in the 100 per cent total of heavy minerals and are not considered separately as was done by Shepard and Einsele (1962) in their study of the adjacent San Diego Trough. Inspection of Table 6 and Figures 39, 40, and 41 shows that the heavy mineral suite of the Santa Catalina Basin surface sediments is characterized by the abundance of orthopyroxene with subordinate hornblende, actinolite, bio tite, and epidote. Orthopyroxene with an average composi tion of hypersthene is by feu: the most abundant mineral and averages more than 35 per cent of the non-opaque heavy minerals. In some samples hypersthene may reach values of 80 per cent of total heavies. Hornblende is present in more samples than is augite and usually in a higher percentage. Epidote is common to many samples, averaging about 10 per cent of the heavies; stations AHF 8315 and NCEL 5 had 45 and 40 per cent respectively. Biotite is more or less ubi quitous. Chlorite and actinolite are present, though in minor quantities only, while glaucophane and muscovite form minor constituents in a number of samples. Such minerals as tourmaline, garnet, zircon and sphene either are present only in subordinate quantities or are completely lacking. Essentially, the basin is characterized by an ^ m s o r* c o o s o r* c o at H H H H r-t H H iH ft ft (*1 ft f) ft f) H 1 tt ^ co c o c o co co co co co oo a a a a s a Augite - - - - - _ _ p* ^ Orthopyroxene 5 5 P P 1 7 + 2 - - 7+ Hornblende 3 - - - - 1 - - P 3 Biotite . - 1 P P 1 - 2 - P 2 Magnetite 2 - - - 1 - 1 - - 3 Rock Fragments 2 - - - - - 1 - P 1 Epidote 3 5 P - 1 3 2 - - 3 Chlorite Glaucophane 2 - - - - Actinolite 2 Muscovite - I P Garnet - Zircon - - - - - Tourmaline - - - - - ^ \ Sphene - - - - - - - - - - % Heavies 4.0 8.7 4.2 3.5 80.4 4.4 1.7 - 4.0 3.0 *P«present s •H s U) I H I K ■ I I I ( a l H . W IO W ^ H AHF 8419 T o m i I i i i i I h M h W M W i AHF 8420 o fell I H I AHF 8421 m m i iioi i.i h h i O h IOuui n i AHF 8422 • o H I I i i I I M H> I IIOIIOI AHF 8423 to "J I i l l i i i i I I i i * i I AHF 8424 • i n » « * * i i ■ I h u to (0 I to m i AHF 8425 0 m l l h> i l to w I IO » l I m m » • * AHF 8426 • m I m • i i h i i i h h l » * AHP 8685 ro m 0 1 i i o m i i 1 1 * 1 i h >) io h ahf 8 6 8 6 m i . M yiiiiiiiiiiiroi.ioovio AHF 8687 « i <4 * 1 i i i o i I ■ n w i i H m * ro AHF 8 6 8 8 \ o» I y* • * i h I h i i o i h i o h i o W h AHF 8689 ! io ! t AHF 8690 TABLE 6 » HEAVY MINERAL COMPOSITION OP SOME SANTA CATALINA BASIN ARE/ (Fraction 0.062-0.185 mm. Composition by point and sand content in frequency numbers) C O 00 ( O 0 0 & 3 2 4 6 1 o o v O o o o v o o o H O V O 00 CM C l 3 2 1 6 2 1 2 1 1 6 2 1 2 1 2 1 1 6 2 1 2 1 2 1 P P 4 4 3 1 2 2 3 77.6 5.2 8.5 9.0 16.0 0.2 16,9 H C M & 1 ( 0 E h n $ t A i n A • i * . A A S 1 1 0 i ( 0 H A E h A E h A E h A A H A E h g g g g g * g g 5 4 3 4 3 4 - - 2 3 5 4 5 4 3 6 6 6 7+ 5 4 4 5 4 - - - - 3 3 3 5 4 4 3 3 3 1 4 3 3 3 3 3 2 2 2 3 4 3 3 3 3 2 2 2 2 - 4 4 4 4 4 4 5 S 5 3 2 3 3 4 4 3 1 1 1 - 2 3 - - m m - 1 - 2 5 6 5 5 3 3 - 1? 2 2 2 2 2 1 1 1 - - 1 1 2 1 1 - - m - 1 2 2 2 2 2 2 2 1 - 1 m m - m - - - m - 1 - - 1 - - - - 16.9 7.2 16.5 2.8 3.3 33.3 4.2 7.5 8.0 3. BASIN AREA SURFACE SEDIMENTS by point count, number*) . ■ VM3NIN AAV3H 3AU.V1ANR3 \f'. " . V*; -V'.:;;-■ ■ ; -^s-i m w x . h^#81&z2 f r y * V:TS: .j .- « ^ ..v . . . . - j , . ^ , , 122 lN 39M 3d 1VU3NIN 1H 0I1 3AllV*inwn9 VARIATION OF COMPOSITION OF THE SURFACE INTERVAL OF LIGHT AND HEAVY MINERAL ASSEMBLAGES FOR THE 0 .2 5 -0 .0 6 1 mm FRACTION OF A SW-NE CROSS SECTION OF THE SANTA CATALINA BASIN, CALIFORNIA _______________________________________ FIGURE 30 f*? • ' . ‘ f . - r J 1 **'■ $ ^ k-^ 4Ct m o u t£ VARIATION OF COMPOSITION OF THE SURFACE INTERVAL OF LIGHT AND HEAVY MINERAL ASSEMBLAGES FOR THE 0 .2 5 -0 .0 6 1 mm FRACTION OFANW-SE CROSS SECTION OF THE SANTA CATALINA BASIN, CALIFORNIA MUM 40 jpfsw , #> / hi 40 mm —, » " ? ' - ' • . • . - . « . % • * : « ; • - i v . v'- ■ ■ ■ ' ■ . . - ■ _ - A V v f - v t - . - i w v M W T I I M E I I E ’ . _*';’* , ■ r» >Cl* ■ ‘ ■■-.» ’ >J ■ > . V £ / VV'/ v ■ • + 7 / 1 “ 40- W O TiTC VARIATION OF COMPOSITION OF THE SURFACE IN T E R V A L OF L IG H T ANO HEAVY M IN E R A L A S SE M B LAG ES FOR TH E a S B - O .O G I m m F R A C TIO N OF A S W -N E CROSS SECTION OF TH E SAN TA C A T A L IN A B A S IN , CALIFO RNIA _______________________________ : _______________ ; _______________ FIOURE 41 124 125 orthopyroxene-hornblende assemblage that is modified by various metamorphic mineral groups such as chlorite-epidote, glaucophane-actinolite, muscovite-garnet, zircon-tourmaline, and sphene. The components of the metamorphic groups are subordinate to the assemblage, and the composition does not properly reflect the distribution or rocks in the presumed source area. The orthopyroxene-hornblende suite is a first- cycle product of low stability and apparently the result of erosion of a mixed volcanic, plutonic, and metamorphic ter rain. Zn contrast to the unstable orthopyroxene-hornblende assemblage c u r e the highly stable metamorphic minerals which usually reflect at least a second-cycle product; however, because of their higher degree of angularity and proximity to a primary source, they are probably first-cycle products. The age of the heavy mineral assemblage is considered to be predominantly post-Pleistocene and possibly in part reworked Pleistocene sands. The major source area is the surrounding islands and ridges. Azmon (1960) established several heavy mineral provinces along the southern Califor nia coast. His Province III is of interest as a possible sediment source if turbidity currents are now operative and cure contributing mainland shelf sediments to the Santa Catalina Basin. Province III is defined by three 126 significant mineral groups, excluding the opaques, with average percentages: 29 per cent epidote and zoisite, 23 per cent amphibole, and 11 per cent pyroxene. In the Santa Catalina Basin, the order of dominant percentages is: or thopyroxene, amphibole, epidote, and augite. This inverse relationship indicates a different source area for the ma jority of the heavy minerals in the surface sediments of the basin. Although most of the sphene may have been derived from Santa Catalina Island, it is probable that some has come from the southern California batholith (Larsen, 1954) by some presumed current mechanism in the Recent or possibly in the Pleistocene and is reworked. Shepard and Einsele (1962) reported relatively high percentages of sphene in the adja cent San Diego Trough and refer the source to the sphene- bearing gabbros and tonalites of the southern California batholith. The markedly fresh appearance of the mineral grains, the nearly total absence of altered material, and the low percentage of stable minerals such as tourmaline and zircon support the assumption that selective weathering of the un stable minerals has not modified to any appreciable extent the mineral composition between source rock and depositional 127 site. Einsele (Shepard and Einsele, 1960) also found a relatively low content of alterItes In the San Diego Trough In contrast to the high percentages In the beach and near shore area reported by Azmon (1960). According to Einsele (1960) only 5 per cent of the heavy minerals In the San Diego Trough had alteration products, whereas nearshore areas had 10 to 30 per cent. The Santa Catalina Basin had less than 1 per cent alterites and if the nearshore area were the source provenance, then one would expect far less contrast in alterites than is present. Whether the altera tion took place prior to, during, or after deposition is not known. Hence, it is apparent that the heavy mineral assem blage of the surface sediments has been derived essentially from another source such as the surrounding islands and ridges and not from the nearshore area. The large micas are represented by biotite, muscovite, and chlorite. Paradoxically, biotite is far more abundant than the muscovite in both the light and heavy fractions. This possibly indicates that (1) the source was primarily volcanic rock, and (2) that in the source area the erosion rate was greater than the weathering rate, otherwise the unstable biotite would have been altered to chlorite or to limonite and clay minerals, depending upon whether reducing 128 or oxidizing conditions were operative, respectively. The metamorphic rocks of Santa Catalina Island and surrounding ridges are probably one of the chief sources of muscovite, chlorite, and biotite. Magnetite is the principal opaque mineral and is pres ent as an accessory in the volcanic source rocks surrounding the basin. The abundance and ubiquity of magnetite suggests oxidizing conditions occur in most parts of the basin, since under reducing conditions magnetite is readily dissolved (Folk, 1961). The ultra-stable minerals, zircon and tourmaline, al though present in low percentages in some of the samples investigated, reflect a metamorphic source. Some zircon is idiomorphic and is believed to be an index of volcanism (Callender in Folk, 1961). Abundance of the moderately unstable minerals horn blende and orthopyroxene indicates a metamorphic and a vol canic source, respectively. Glaucophane, abundant garnet, and epidote denote a definite metamorphic source. Although magnetite, tourmaline, zircon, and sphene can form authigenically in sediments, no evidence was found to indicate that this has happened in the Santa Catalina Basin. 129 Light Minerals The minerals of the light fraction are quartz, feld spar, biotite, and muscovite and are listed in Table 7. Variations across the basin are shown in Figures 39, 40, and 41. Grains sure mostly fresh and angular, and show few, if any, weathering effects. Although biotite is present, it has largely been concentrated in the heavy fractions. Plagioclase composition estimated on the basis of refractive indices is chiefly andesine. Potash feldspar was recognized in only 6 samples. Four samples containing abun dant rock fragments contained dark chert with a refractive index s 1.50. The detrital chert is generally believed to be diagnostic of an older sedimentary source. Ratios of quartz and plagioclase and potash feldspar were determined for 6 samples because these were the only ones containing potash feldspar. The ratios sure variable, but plagioclase is greater than quartz and potash feldspar in 3 samples and equal to wartz and greater than potash feldspar in 2. The average ratio of quartz: plagioclase: potash feldspar is 8: 14: 3. Shepard and Einsele (1960) determined an average ratio of 59: 33: 8 for the San Diego Trough. t 22 2! ^ J h h h c m h h h c v j C O C O C O C O G Q C O C O O O C O C O w Quartz 2 1 1 1 2 . 2 1 2 2 1 1 Rock Fragments 5 7 6 7 3 7 6 7 6 7 7 Plagioclase^ 2 1 1 1 3 2 2 2 2 3 3 K-Feldspar - - - - - - - - - - - Biotite 1 - 1 1 - - Muscovite- - - - - - - - - - - Chlorite - - - - - - - - - - - Organic 8 7 8 .7 8 7 8 7 7 6 6 Quartz/Feldspar 1 1 1 1 0.67 1 0.5 1 1 0.33 0. % Light Minerals 96.0 91.3 95.8 36.5 19.6 95.6 98.3 100.0 96.0 97.0 95. aChiefly dark chert 2% RI - 1.50t ct 3% RI- 1.50i ^Plagioclase composition range - oligoclase j g e ■ oligoclase andesine s£* o » f- > o I I h l IO Ot IO A H F 8418 m o SO * « i o O ' I i i I w >i h AHF 8419 • ' • o u w (O _ m o O' * l l i w <4 H AHF 8420 • • O u u so o C O I I h l u w M AHF 8421 m O ' SO _ > t o io i i io u a u A H F 8422 O ui O ' 00 a > h o < i I i I io ^ io AHF 8423 c o so W h >J I l I l IO si io AHF 8424 m SO 0 9 h >1 l i h I W > J io AHF 8425 £ +* ** i i t i t o io AHF 8426 2 I i I i l H M IO A H F 8685 00 O ' JO » ►- » I l IO w ^ » AHF 8686 u» $ I o» I i m m io I io AHF 8687 UI So • i r i H » io AHF 8688 A ■ -a l l I I h io AHF 8689 • 00 «P | O' I • i i N si w AHF 8690 w TABUS 7 COMPOSITION OF THE LIGHT FRACTION OF SOME SANTA CATALIN (Fraction 0.062-0,125 n un. Composition by and sand content in frequency numb 01 < n $ (0 £ a A * (0 in A vO A r* A A A a H H a N 8 g g g g g ■ 1 1 1 1 2 2 l 5 5 6 5 4 2 2 2 3 3 3 4 3 2 - - - - ? 1 ? - 1 1 2 1 1 - 1 - - - • - - - - - - - m 8 8 a 8 8 8 7 0.5 0.33 0.33 0.33 0.5 0.5 0, 92.8 83.5 97.2 96.7 66.7 95.8 92, ft (0 o H (0 1 3 I 7 0.67 1 H H 8 1 7 1 7 1 HE SANTA CATALINA BASIN SURFACE SEDIMENTS Composition by point count, n frequency numbers) o H (0 1 3 I 7 .67 1 H in IO CO 3 H H H H H H (0 0) (0 (0 (0 (0 H H H EJ H g g g g g g 1 5 2 2 2 2 7 6 5 7a 5 7a 1 5 3 2 3 2 7 1 7 1 8 0.67 7 1 8 0.67 1 6 1 a 8 0.67 H i i 5 3 8 cvt * «*» * H A W g 01 A 7C 2 1 m 7 .0 96.6 98.5 89.7 97.3 99.2 97.5 55.1 95.6 77.5 98.7 70.5 95.0 87.5 131 The unusual abundance of the plagioclases, some of which sure zoned, and the lack of potash feldspars indicates a volcanic source for most of the feldspars. The absence of feIdspars in 3 samples may indicate that very little or no feldspar was available at the source area. This is especi ally true where schists, phyllites, and older sediments were the source rocks. The metamorphic rocks and acidic igneous types on Santa Catalina Island and adjacent ridges are probably the chief source of muscovite. Organic fragments of foraminifera, diatoms, radiolari- ans, and chitinous materials make up 30 to 85 per cent of the samples. Rock fragments ranged from 5 to 60 per cent of the light fraction. NCEL stations 1 and 2 contained 2 to 3 per cent pumice. The presence of volcanic glass is rare in the surface sediments and represents explosive eruption of siliceous magma; the source is unknown. CLAY MINERALOGY General Statement The Santa Catalina Basin represents an accumulation of sediments principally derived from soil material from the southern California mainland and adjacent islands. Clay minerals are significant factors relating to the mass of the deposit, the properties of the sediment, and the character istics of the water column through which they pass and set tle. According to Mason (1962), clay minerals of the 2:1 expanding lattice type may scavenge ions from sea water and consequently change the concentrations of certain ions sig nificantly, both of the water mass and of the clay mineral. Also, they may be an important factor in the concentration and incorporation of organic matter into the sediment by virtue of organic matter adsorbed on clay surfaces. Little research has been undertaken on the clay miner als of the basins in the Continental Borderland. What data that have been published were compiled and summarized by 132 133 Emery (1960). He found that among 3 sets of analyses by 3 different groups of workers for the same basin, there was a great degree of dissimilarity between interpretations. Apparently, differences of interpretation exist for essenti ally the same samples, and in order to bring order out of chaos, the objective researcher must use some standard tech nique and interpretation to analyze his data. Towards this end, the following outline of methods used is reviewed. Methods X-ray analyses for 36 basin sediments were analyzed through the facilities of the Chevron Research Corporation, La Habra, using standard X-ray diffraction procedures. Methods used followed those of R. W. Rex of Chevron Re search, with modifications as required by the samples. Samples N0TS-4B to NOTS 19, N-G-l to N-G-3, and AHF 8314 to AHF 8687 were X-rayed with an automated General Electric X-ray diffraction machine using nickel-filtered CuK^ radia tion and a high-angle spectrometer goniometer. Patterns were made from 2° to 14° (2 ®). Samples NCEL-1 to NCEL-5 were analyzed with a Phillips X-ray diffraction machine using a similar source and goniometer; however, patterns were made from 2° to 40° (2 ®). 134 All samples run on the General Electric X-ray machine were prepared from the <2\i fraction of calgon and/or HgOg dispersed surface sediment. Samples NCEL-1 to NCEL-5 ana lyzed on the Phillips X-ray were prepared from the >4n fraction. Three oriented clay slides were prepared by pipetting a dispersed clay-liquid suspension onto the sur face of porous porcelain plates and air-dried. One slide of each sequence of 3 was heated to 600°C, a second slide was sprayed with glycerol using an atomizer, and the third was retained as the oriented air-dried sample. The main advantage of using porcelain slides is that they give a homogeneous distribution of the clays instead of a fraction ation with kaolinite setting first and montmorillonite last, masking out the coarser minerals. Three clay mineral spe cies were determined: montmorillonite, illite, and kaolin ite. Chlorite was recognized in some samples. A semi-quantitative method was used to determine the relative percentages of clay minerals. The areas under the peaks of diffractograms for montmorillonite, illite, and kaolinite were obtained by using a planimeter and these values were assumed to be a measure of the abundance or relative weight of the clays in the sediment. The various clay minerals were distinguished by the 135 following criteria of McAllister (1964): Monfamfillonite has a 14.5 A (001) basal spacing in the air-dried sample, which expands to about 17.7 A upon saturation with glycerol, and collapses to 10 A when heated to 600°C. Illite is char acterized by a 10 A basal spacing, which is not affected by glycerol adsorption and only the peak height is intensified at 600°C. Kaolinite shows a strong 7 A basal spacing and a (002) at 3.55 A. They are not affected by glycerol ad sorption, but both disappear at 600°C. Chlorite has a strong 14 A basal spacing and a 7 A second-order reflection generally lost in the (001) of kaolinite. If distinguish ed) le, a unique (003) peak at 4.7 A is diagnostic. These spacings sure unaffected by glycerol adsorption, and when heated to about 550°C the 14 A peak intensifies and the others weaken and disappear. Halloysite, vermiculite, and mixed-layer clays were not identified. Results Table 8 shows the percentages of montmorillonite, illite, and kaolinite obtained. The values listed were determined by using form factors of 2 and 4 for montmoril lonite. Results of the X-ray diffraction study indicates that a fractionation of the basin clays has occurred and the «**• • 136 ■ o r cm * u m m i n t v itm c u m j m h i m m m , cm i m m i * I M m Ui M a r . h i » i ifn • hn h im i l l a l t tm a M U M l l l M l u ) S B M tU ftto M /f ■ II1 1 0 4 w / t ■ ■■!!•■ ■ i l f t r a t u Vara t V M M 4 ^ r* ®/4 O r a a f i r t t 4 V* ■ a n a i M t a f 4 m « # t o t u . a / T m a i.a u . a 1 , 0 ) 4 / > T . » u a . a n . a ■ O ft | u . a aa.a # J % . aa.a >4.1 a . w o / > l . o u U . 4 41,1 won a a.a a.T a . n i / / T m aa.a a . a 0 . 0 1 4 / < , U f t 4ft .4 u . a ■ova v u . a aa .a a . a a t / « < a u aa.a 44 .4 1 . 0 4 4 / < 1 0 0 44.4 n . 4 ■ o ta a fta.a 14.1 / T m t f .4 a . a a . a a o / - n , M i u . a U . 4 ■ova a u . a U .V 4 ,4 0 4 / A M B aa.a u . a • • V n a U .V 44,1 I ■ova la H . t aa.a a . i a a / < 7 v u a . a 41.1 a , v a # / u . a IV *4 f ■ova i t a.« U .V l . N t / / < I 1 4 n . 4 m . o t $ ? T n a u . a U . l a m u a .a 11.4 o . m / / . M aa.a u . a v . v ia ^ > 1 * 1 4 0 u . a n . a wen i» a,a u . a N . l u . a 0 . 0 1 0 / < | , 4 U va.v M .O m i« u . a iv .a 0 . 4 4 4 / *< 4 4 4 a . a u . a i.a a a ^ . > 1 . 4 0 1 u . a a . a » wen i t u . a a i.a 4 . 4 1 0 / < T a n n . a 41.1 I ■ o ta u a.a a .a ' 11.0 M .O o . a a o / O . W n . a « . • ■ o ta ia * a i.a u . a u . a n . 4 4 . 4 1 0 / < . n o 10.1 U . 4 J ■ova iv a.a a .v a . t a > / f m 11*0 aa.a 4 l J V T i a u . a U . V m t a m u . a aa.a o . u a / / 1 . 4 W a.a U .V 1 .4 4 0 / < , 4 1 1 u . a u . l n o o m la .a u . a “ % i 14*1 n . i . 4 . 4 4 4 / < . o a V I.4 44.1 ■ a a m a .v u . a 14.4 04 .4 “ S f T m H .V a i . i M r a iiv a .a f t i .f t ,M>Sm u . a aa.a > T M V I.4 • v .a M r aaaa 4 .4 T . l u . a n . a . . u * , ' T M n . a M .O m t o ttft U .V ia .v 0 .4 M / X m i a i.a 14.4 a i.a u . a m t a m u . a u . a t . l N > <<•11 u . a a i . i ‘ % T m . u . a a i.v m t m i u . a ia .a a .a a / u . a n . i I.T M K , u . a U . 4 M M H l . a n . i 0 . 4 4 1 / / f l U u . a n . a « . » M ^ O . W u . a a a .4 m t a a a a ia .a ia .a 0 . 4 1 1 / / M l a i.a 44.4 u . a U . l tm a o a a .f t ia .a a . 4 a > / M l 11.4 n . a I . N t « / T M U . l * a i. a ■ M a m a .a u . a a . a u / / » 1 V t l . f t N . l 41.0 41.4 tm BUT a .a u . a * ! T m . 0.1 14.4 0 , 1 4 4 / < . 4 0 1 41*4 n . a ■-•-ft u . a aa.a 11.4 u . a 4 . 4 4 4 / /l . W n . a 4 1 .4 •■ •■ a u . a u . a u . a n . a 4 .0 1 0 / u . a 4 1 .4 M-l ia .a u . a 0 . 4 0 / -<40 aa.a u . a 0 . 4 U / /T.oa u . a U . 4 net^ft aa.a N .4 0 . 1 4 4 / < v a u . a 41,1 ■ . 1 0 / < U 4 n . i 11.1 K V U I aa.a aa.a 1 . 0 4 4 / i i . a u . a * 1 . 1 0 4 / < 4 U u . a n . a ■ c a i/a aa.a iv . a 0 . 0 1 0 / u . a u . a I . 1 U / < a v n . a a i. a ■ c s i^a aa.a aa.a 0 . 4 4 0 / < 4 1 1 u . a a . a i . o a / < 4 4 1 41.4 n . a ■ ca i^a aa.a 44. V u . a n . a 4B.0 U . l j M i f f i f a l l I ■ U t U M M M f l M M i i « n W | 1 a u . a I B. & T aa.a u . s a U . 4 1 0 / * < 4 .0 0 0 . 4 4 4 4 - « < a u ai.a 00.41 a n . t 00.04 1 0 1 . 4 0 / ' u . o m 4 * 1 1 1 / 4 . M I a u a .o u . v o M N J 4 4 . 4 4 a w a y M % U l . l l U t i a M M V 1 M K t l ^ l f l y ■ M .M u . a it . v a a . o i v / a m * 1 l U / / a n a 140.4 aa.aa u a . a t l . N v . a u / < . a a v 1 . 4 0 / <0 4 4 4 1U.V 1.0ft u i . o 0 4 . U 137 dominant clay mineral in the <2|i fraction is montmorillonite with moderate to minor amounts of illite, and minor to in significant portions of kaolinite. As shown at stations NCEL-1 to NCEL-5 (Table 8), illite and kaolinite are equiva lent to or greater than some of the coarser montmorillonite which is concentrated in the coarse >2| j l to <31| j l fraction. The low values for kaolinite and illite in the <2|i fraction are due, in part, to possible differential flocculation and deposition of these minerals near shore. Also, a portion of the low values appear to be due to fractionation of the larger-grained illite and kaolinite which seem to be con centrated in the >2jj size grade. Consequently, if the silt fraction is not included in the analyses, the total amount of clay minerals in the sample will not be recorded. X-ray results indicated the presence of quartz, cal- cite, aragonite, plagioclase, orthoclase, and phillipsite (?), in order of their relative abundance based upon peak height-ratios. The average quartz-to-feldspar ratio was 7:1.33 and the average plagioclase-to-orthoclase ratio was 1:0.36. GEOCHEMISTRY General Statement Geochemical evaluation of a single stratigraphic hori zon within a basin is of great value for comparison of modern basins and with similar horizons in the geologic column. Thus, analyses of carbonate, organic carbon, nitro gen, and major and minor elements for 46 surface samples (0-3 cm) of the Santa Catalina Basin were made in order to establish some of the chemical components of the sediment. Major and minor element distributions are generally related to the component minerals or mineral with which they are associated. Speculations derived from the major and minor element distribution can be related to the early dia genesis of the sediment and the physical conditions of sedi mentation (Nicholls and Loring, 1962). Calcium Carbonate Analyses Calcium carbonate was calculated from the weight 138 139 percentage of total carbonate obtained by a modified gaso- metric technique of Bien (1952) and Hiilsemann (1964). No attempt was made to differentiate coarse or fine fraction carbonate and values for calcium carbonate are listed in Table 9. The highest and lowest values for calcium carbon ate are 59.63 and 5.65 per cent, respectively. The average for the basin is 18.8 per cent. A scatter diagram of calcium carbonate versus median diameter (Fig. 42) shows a tendency towards a greater con centration in the finer grain sizes which is in accord with Emery*s findings (1960). This presumably reflects a higher concentration of reworked detrital calcium carbonate, which may be comminuted or small foraminifera. The percentage of calcium carbonate is more or less constant with depth in the basin, although there is a very slight tendency for it to decrease with depth (Fig. 43). Standard deviation and percentage of calcium carbonate plotted against mean dia meter (Fig. 44) indicates in general that the poorer-sorted sediments have the greater range and lower calcium carbonate values than the better-sorted sediments which generally have higher values. Also, total calcium carbonate generally de creases with depth in most cores. The distribution of total calcium carbonate within the / a C A L I 140 M ap!* M a M t l (a) M a tte l a U t n l I t ) ■JoMafcl M tx * |ta CM t n t a l a Matte* ID C17M* o r ta a la Carla* CM C alais* Carta**** <*> JW VII4 1M 7.1 *-> t . m l.W * t . l l ll.M MT « IU 1111.4 M l 1.444 t.wt 4.M U .W M M U i n t . * M l *.114 t.tu l .M M.M M t t i l t I t M . t M l t.4 T t t.m 4.W ll.tt •Mt M U M.t M l t .M I t . m l . t l t M .t l M t tilt IM T .t M l t . * U t . t w l.W 1 4 .U M t M M lM t.4 M l t . l l * t . t w *.47 U . l t M t t l t l IM T .t M l t . m «.*** l . t t U .W M t M U 11*4.1 M l t . m 1.171 l . t l U .1 7 M t M U T M .t M l t .o a i 1.411 7,14 U .l * M t M M T M .t M l t . u t t . t w l . U *7.74 M t M t l I t t . l M l t.m 4.4*4 l . t l U .W M t M M • 1 0 ,t M l t .W l t.ltt t . l t • l . t t t a r M t* 1 U 4 .I M l t.4 M 7.7W t . l l M .M M t M M U U . t M l t .W l I .M t 4.71 •1.41 M t M t* 1*48. t M l 0 .4 U 7.7W 4.11 M .M JUT M M T M .t M l t.wt I.OM t.m 17. M M t M M I M t,* M I t.wt 1.4M t.tu U .W M t M tl 10*1,7 M l t.m l . t t t t.tt M .I1 M t M M 11M .4 M l t . i w I .M t i . tt M .W M t M M t t t . 4 M l t.* 1 7 t . t l t t .M I M .M M t M M 7*1.» M l t.m t.m l.W M .W M t M tl l U t . t M l t.tu t.tu t . m 17.17 I t M M U U . t M l t.tw 1 .171 a . u M .tT ' M OM > 1 U M .I M l t.ut t . t w l . U 11. U , *O W '*-l 1171.4 M l 1.4*7 t.tu l .M U . l t MOM a 1 i t t t . t M I t . m t.tu l . U U . l t MOM-** I M t.* M t t . U I t . m l.W t . M MOM-1 lllt.l M t *.*17 7 .4 U l . U ' U .W M O W « ll*7.t M* t.*n t .M I l.W U .t* MOM-7 i t * . 4 M* t . 4 U t . m 4 .U M .l l MOW-* lltl.t M* t.tw . 1 .0 4 l .M M . t l M W -t 7 (7 .t M* t .W l l . t l t t.m U .W M W -It 10M .4 M l t . l l * * .t w l .M M .M MOM-11 *0*4.t M* t.wt t . t t l l.M U . t l MOM-11 I t t t . t 0-1 t.m t . t u t . w t M .M MOW-U - M t . t t . u t t.m l . t t U .W M M -17 Itll.t M l t.* * 7 t.tu 4.7* • l .M MDW-U tu.t M l t . l l * l . I U l.W U .M M0W-1M t T t . l M* 1.4*4 t.tu 4.W M .M M W -U 7 * t.t M l t.M 4 t . i t t l.W U .M MCMW 1117.* 4 .4 U 7.7* 4 .M 7 .M a c a ir t U U . t M t t .4 U t . t t . 4.4* U .M MC4V-I U M .I t.iu t . t l 1.44 • l . t t MCtlrt 1*41.1 M* t.tu t . l l 4 .M U .M MCttei I t M .t M* *.441 7.74 4.7* U . l t 1 4 1 6 0 - 5 0 - 0 4 0 - Z J O - 20— 10— 10 100 MEDIAN DIAMETER |i UNITS 1000 R E L A T IO N S H IP BETWEEN C aC 03 AND MEDIAN DIAMETER OF SURFACE SEDIMENTS FIGURE 4 2 c ' P E R C E N T C a C O , ) 25 3 50 1 • u • • • 2 5 0 - i 5 0 0 - • ■ • 10 Q C hi U 7 5 0 - 2 • • • • • • • z • • , • 5 1 0 0 0 - • • a Q . L lI O • •* • «c • • 1 2 5 0 - • • • • • • • r • . • 1500 — - • • f t i 3U RELATIONSHIP 9ETWEEN CaCO* AND DEPTH IN THE SANTA CATALINA BASIN FIGURE 4 3 B313WVI0 NV3W t — CM 143 K> O o O o UJ o oc Ui 0. C r t z o K < > Ui o o oc < a z < h (O RELATIONSHIP OF MEAN DIAMETER vs STANDARD DEVIATION AND C aC 03 OF SURFACE SEDIM ENTS FIGURE 44 144 basin is shown in Figure 45. The maximum values occur along the western slope of the basin and on the Emery Seaknoll, and consequently there is a definite relationship between depth and calcium carbonate distribution. The lowest value (5.7 per cent) occurs in the northern basin flat and low values also occur in the southeastern part of the basin, but this may be due to dilution by clastic sediment. A comparison of calcium carbonate to topography and other parameters is shown in Figure 46. Organic Constituents Nitrogen ftnalyaee Nitrogen was determined by a micro-Kjeldahl technique (Niederl and Niederl, 1947). Values are listed in Table 9 and contoured in Figure 47. Nitrogen content in the basin sediment ranges from 0.021 to 0.579 per cent and averages 0.323 per cent. A plot of nitrogen and standard deviation against mean diameter shows that the percentage of nitrogen increases with decreasing grain size and that higher values are asso ciated with the poorest sorting (Figs. 48 and 49). Nitrogen content is also found to increase with depth of water (Fig. 145 40' to' to (O' 4tf 4 0 ' IK* DISTRIBUTION OF TOTAL CALCIUM CARBONATE CONTENT OF THE SANTA CATALINA BASIN, CALIFORNIA 146 n w * 4 • I 0 0 iJ J tO O A J J 4 0 0 * Si 6 0 0 • 0 0 _ _ _M£AN_ £i**LIt5 — _ ____ STAfiOAHQ DEVIATION _____ 1 0 w -J itwmd t H v nnos % ?j>t ))>y) > rr ! * • * o 0 i j f * 0 0 40 ° g| * 0 0 * *00 AN_ DIAMC TER _ j - ^ ~ - — STANDARD DEVIATION >TT? U^- (llO W C T tltS * SURFACE SEDIMENT VARIATION OF PERCENT CoCOj. TOTAL ORGANIC MATTER. NITROGEN, MEAN GRAIN DIAMETER. AND STANDARD DEVIATION WITH D E P T H ACROSS THREE TRANSECTS OF THE SANTA CATALINA BASIN. CALIFORNIA _________________ • FIGURE 46 147 40' (O' I I I * M 01 0* OJ 0 4 0 4 O S »• 4 t f It * * 40 : DISTRIBUTION OF ORGANIC NITROGEN OF THE SANTA CATALINA BASIN, CALIFORNIA n o * • • •% C O _L CO i S1INO 4> «3X3WVia NV3W • • * \ .. * V - ■ - .. to ■ o t n * o o ui (9 O ac H w. Z o Ui o s “ ° o. 148 O t f > — K> — CM > Ui a o t c < a in RELATIONSHIP OF MEAN DIAMETER vs STANDARD DEVIATION AND NITROGEN OF SURFACE SEDIMENTS figure 48 149 0.6- 0 . 5 - ••• • • 0.3- 0.1- 0- 1000 10 100 MEDIAN DIAMETER p. UNITS RELATIONSHIPS BETWEEN NITROGEN AND MEDIAN DIAMETER OF SURFACE SEDIMENTS FIGURE 49 150 50). The baslnal distribution of organic nitrogen may be seen in Figure 47. A comparison of organic nitrogen versus calcium carbonate (Fig. 51) indicates that in general the areas of high organic nitrogen are relatively low in calcium carbonate, as for example the Emery Seaknoll and the southern basin flat and that low nitrogen and high nitrogen values sure related to coarse and fine grain sizes, respectively. A comparison of nitrogen to topography and other parameters is illustrated in Figure 46. Organic Carbon Analyses Total carbon content was obtained by dry combustion with a Leco apparatus and organic carbon determinations were made by difference of total carbon and carbonate carbon and by the chromic acid reduction method of Allison (1935). Although the use of the Allison method assumes that the organic matter in all the sediments in the basin is at the same state of oxidation and disregards the presence of oxi- dizable pyrite (I. R. Kaplan, personal communication, 1$65), it yields only approximate, though reproducible results. The presence of pyrite in the sediment was verified by X-ray analysis. Rittenberg, Emery, and Orr (1955) found that 151 0 250 500 < / > QC U J I — w 750 >.1000 < L U J o 1250 1500 (750 PERCENT NITROGEN RELATIONSHIPS BETWEEN NITROGEN AND DEPTH IN THE SANTA CATALINA BASIN FIGURE 50 0 . 1 0.2 0.3 0.4 0.5 0.6 152 O O QC UJ o oc 0.6 0 .5 - Fine grained sed im en ts 0 .4 - 0.3- t 0.2- 0.1 , Coarse grained sedim ents 10 20 30 PERCENT C aC 03 RELATIONSHIPS BETWEEN CaC03 AND NITROGEN OF SURFACE SEOIMENTS FIGURE 51 153 surface sediment to a depth of about 1 m in the Catalina Basin had a positive Eh indicating an oxidizing condition. The highest percentage of organic carbon was 5.460 per cent and the lowest 0,190 per cent. The average organic carbon value for the basin was 3.230 per cent. Values for the organic carbon may be found in Table 9. The average ratio for organic carbon to organic nitro gen (C/N) is 9.5 for the basin. The C/N ratio for the Santa Catalina Basin is higher than Trask's (1939) value of 8.4 which is somewhat below the 11.3 value reported by Emery and Rittenberg (1952). The general average of 10 used by Emery (1960) for basin surface sediments was obtained from an average of Trask1s and Emery and Rittenberg's average values. This average closely approximates the 9.5 C/N ratio deter mined in this study. Carbon/nitrogen ratios increase slightly with depth and statistically no significant trend exists laterally in the surface sediments. According to Ketchum and Redfield (1949), C/N ratios for planktonic organisms range from 6.7 to 8.3. These val ues are lower than the average for the Catalina Basin sedi ments and the increase in C/N ratio may be due either to bacterial decomposition with a resulting loss in nitrogen (Debyser, 1961) or to differing rates of sedimentation or 154 varying rates of organic matter production (Emery, 1960). Organic Matter Both organic carbon and organic nitrogen cure a measure of the amount of organic matter present. The ratio of or ganic carbon and organic nitrogen to organic matter varies as the state of oxidation and the type of organic matter. Emery (1960) used a value of 1.7 x organic carbon or 17 x organic nitrogen as a means of estimating the total quantity of organic matter in basin sediments. The same factors are followed in this report and values for total organic matter are listed in Table 9, and a distribution map is presented in Figure 52. Organic matter of the surface sediments ranges from 0.357 to 9.758 per cent and averages 5.7 per cent for the basin system. Organic matter decreases with increasing depth within the cores. The higher values of organic matter are in the finer grain sizes and the lower values are in the coarser sediments. Organic matter increases with increasing percentages of clay-size fraction (Fig. 53). A comparison of organic mat ter versus percentage of diatoms and radiolarians in Figure 53 shows a general increase in organic content with increas ing percentages of diatoms and radiolarians. The relation- 155 40' I l f (O' sv u* 4 0 ' So1 *(? D IS T R IB U T IO N O F O R G A N IC M A T T E R OF T H E S A N T A C A T A L IN A B A S IN , C A L IF O R N IA i n * 156 U311VW 3INV0U0 IVlOi. lN39H3d •• VARIATION OF TOTAL ORGANIC MATERIAL vs PERCENTAGE OF CLAY-SIZE FRACTION AND DIATOMS AND RADIOLARIANS FIGURE S3 157 ship of organic matter to topography and other parameters is shown in Figure 46. Spectrochemical Analyses Major Elementa Forty-six bulX-sediment samples from the Santa Catalina Basin were analyzed spectrochemically by Los Angeles County a facilities and the Pacific Spectrochemical Laboratory. Additional analyses were obtained from the Chevron Research Corporation, La Habra, California. Appendix C gives the results of spectrochemical analyses of the surface interval (0-3 cm) from 46 cores. No attempt was made to differentiate detrital and non- detrital major and trace elements. Pre-analysis treatment included an initial drying at 200°C, reduction to a fine powder by grinding with an automatic agate mortar, and finally ashing at 500°C. According to Hirst (1962), the distribution of the major elements (silicon, aluminum, iron, sodium, potassium, magnesium, and titanium) in sediments, developed by normal sedimentary processes, is usually determined by their vary ing clay mineral content and to a lesser extent by the more 158 Important aluminum-bearing minerals such as the feldspars and micas. However, under some conditions chemical composi tion and enrichment is at a minimum and the chemical compo sition is controlled by its mineralogy to a greater extent than by the physical conditions of sedimentation. Silicon is by far the most abundant element and varies roughly antipathetically with the clay mineral content. The silicon contents of the basin system sediments vary between 15 and 25 per cent and the average value is 19.1 per cent, which is below the average silicon figure of 29.0 per cent for argillaceous rocks cited by Rankama and Sahama (1950). Much, if not all, of the silicon apparently has been deposited either as detrital quartz or structurally combined in the aluminosilicates, such as feldspars, micas, chlorite, and the clay minerals. The distinct relationship between higher silicon content and higher concentrations of sand size fractions near the topographic highs indicates the higher concentrations of free quartz and unaltered alumino silicates in these sediments. The generally lower values of silicon in the deeper water sediments, especially those found in the basin flats (stations AHF 8429 and AHF 8320) are presumably due to the lower quartz contents and lower silicon contents of the finer-grained aluminosilicates. 159 Aluminum is the second most abundant element, ranging from 4.6 to 12.0 per cent and averaging 8.8 per cent. The varying aluminum contents exhibit a slight tendency to re flect the varying clay mineral content and generally there appears to be a differentiation in respect to sediment types. A correlation of higher values in the deeper water finer-grained sediments is not readily apparent, as one might anticipate. As a consequence, this inconsistency of the distribution of aluminum suggests that possibly grain size may not be the controlling factor, but rather the mineralogic nature of the bulk sample may be more important in the aluminum distribution. If spectrochemical analyses of both the coarse and fine fractions were run, it might be possible to corroborate this view. That is, the importance of the mineralogy would be ascertained if the aluminum were found to be equally divided between the coarse fraction (>0.061 mm) containing abundant feldspar as a main source of aluminum, while in the finer fraction (<0.061 mm) the phyllosilicates were in greater quantities than the feld spars. Furthermore, it is possible that the type and amount of clay mineral, as well as the amount of substitution for aluminum in the octahedral positions may be larger contribu tors to the final aluminum content. Hirst (1962) believed 160 that the relatively low aluminum content of Gulf of Paria clays may be due to the presence of considerable illite +++ +++ (with some substitution of A1 by Fe ) and montmorilIon ite, a mineral with low aluminum/silicon ratio and consid erable substitution of Al+++ by Fe+++ and Mg+++ in the octa hedral positions. Also, according to Keller (1953), green ish-colored mud is indicative of ferric silicate, therefore the general greenish color of the Catalina Basin sediment +++ may be taken as evidence of such substitution of A1 by Fe+++. The average aluminum contents of the Catalina Basin sediments sure comparable with the values for argillaceous rocks (Clarke, 1924) and the greenish muds from the Gulf of Paria (Hirst, 1962). These values are still below the con tents of argillaceous rocks reported by Mohr (1955) and Spencer (1957) in Hirst (1962). Presumably, the variation of the silicon/aluminum ra tios within the basin system reflects the relationship be tween quartz and the aluminosilicates. The average silicon/ aluminum ratio of 2.54 is lower than the 3.1 average for 52 terrigenous rocks reported by Clarke (1924), but is com parable to the estimated ratio of 2.56 for greenish muds from the Gulf of Paria (Hirst, 1962). 161 Sodium contents range between 1.3 and 3.6 per cent and average 2.4 per cent, whereas the potassium contents range between 0.71 and 8.5 per cent and average 2.5 per cent. The high value for sodium Is chiefly due to sodium In the form of dissolved solids contained In the interstitial water; a small portion of potassium is of the same origin. Potassium content is higher in the finer-grained higher clay percen tage sediments, while the sodium content shows no systematic distribution pattern. The sodium/potassium ratio of 0.96 is much higher than the 0.36 value reported by Rankama and Sahama (1950) for argillaceous rocks, yet it is reasonably close to Hirst's (1962) value 1.06 for greenish muds. The calcium contents range between 3.0 and 18.0 per cent and average 8 per cent. The great variation of calcium apparently reflects the various contents of calcareous or ganic detritus. Calcium can probably occur as calcium carbonate in shell debris or inorganic precipitates (<0.05 mm), as calcium phosphate, in 12-fold coordination in mont- morillonite, or in the plagioclase feldspars. Magnesium averages 3.11 per cent and ranges from 2.0 to 4.4 per cent. The magnesium values are higher than nor mally found in igneous rocks (1.26) and argillaceous rocks (0.89) by Rankama and Sahama (1950). Emery (1960) reported 162 a 2.1 per cent average for the Catalina Basin. The high magnesium values may be associated with the high montmoril- lonlte clay fraction In which the magnesium Is probably In cluded In the montmorlllonlte structure. Possibly some magnesium has been incorporated into the sediments from solution. Total iron ranges from 1.0 to 15.0 per cent and aver- + + ages 4.08 per cent. Iron may occur as Fe or Fe sub stituting for magnesium or aluminum in the lattice of clay minerals or in glauconite. Sediment colors suggest that the + + majority of iron is present as Fe . The fixation of the iron may have occurred at either the source, during trans portation, or in the basin of deposition. The inconsistency of the aluminum/iron ratios across the basin system suggests that the fixation of Fe may have occurred either during transport or at the site of deposition; however, the pres ence of glauconite, pyrite, and hydrotroilite tends to com plicate this interpretation as well as a secondary source area. The average iron content of igneous rocks is 5.0 per cent (Goldschmidt, 1937), and shales average 4.71 per cent (Clarke, 1924). Hirst noted an average iron content of 5.08 per cent for greenish muds in the Gulf of Paria and Emery (1960) reported values of 4.3.and 4.5 for the Santa Barbara 163 and Santa Catalina Basins, respectively. A plot of iron/ aluminum ratios against percentage of aluminum in Figure 54 indicates that aluminum is the major controlling factor for iron in the basin sediments. In the Santa Catalina Basin, titanium ranges between 0.25 and 1.5 per cent. The average of 0.76 per cent for the Catalina basin closely approximates Goldberg and Arrhenius's (1958) value of 0.73 per cent for red clays. Steiger, in Clarke (1920) reported an average titanium percentage of 0.76 per cent for blue and green muds, which is equivalent to the value in this report; however, Emery (1960) reported a much lower value of 0.50 per cent for both the Santa Cata lina and Santa Barbara Basins. It should be noted that Emery's average included smaples from the entire core and not just the surface interval as herein reported. Minor Elements Strontium values range from 0.015 per cent to 0.070 per cent and average 0.038 per cent. Emery's (1960) stron tium average of 0.040 per cent is comparable to the 0.038 per cent reported here; but both values are much lower than the value of 0.071 per cent given by Goldberg and Arrhenius (1958) for Pacific pelagic sediments. The average strontium 164 12 H II- ••• 10- _ 9- 7- 6- 0 1 . 0 0.4 0.8 02 0.6 PERCENT F«/A I VARIATION . IN THE RATIO OF TOTAL IRON TO TOTAL ALUMINUM WITH PERCENTAGE OF TOTAL ALUMINUM FIGURE 54 165 value for igneous rocks is 0.034 per cent, which is slightly below the reported value for the Santa Catalina Basin and indicates a slight tendency towards concentration of stron tium. The highest content of strontium (0.070 per cent) for the basin system occurs in AHF station 8318, a San Clemente Island shelf sediment which was high in shell material. There is a general tendency in the argillaceous sediments for relatively high strontium values to be associated with the clay-size mineral fraction. An inverse relationship is seen in Figure 55, in which the strontium/calcium ratios are plotted against percentage of calcium and indicate that calcium is not the major controlling factor for strontium contents in the basin. Manganese content ranges from 0.089 per cent to 0.000 per cent and averages 0.036 per cent. Comparison of the manganese content with the average values of other workers indicates that the average of 0.036 per cent is about one- half of Emery's (1960) value of 0.064 per cent and only one- sixth the value for green muds (0.020 per cent) for the Gulf of Paria given by Hirst (1962). Although barium ranges from 0.049 per cent to 0.43 per cent, it averages only 0.092 per cent in the basin sediments. There is a general relationship between barium and high 166 . K> -s* - o -» • •• — ID <M 01 v 03/4$ l N 3 0 d 3 d VARIATION IN THE RATIO OF TOTAL STRONTIUM TO TOTAL CALCIUM WITH PERCENTAGE OF TOTAL CALCIUM _______________ FIGURE 55 167 values of organic matter and clay-sized minerals. Also, there is a tendency for barium to be associated with higher percentages of radiolarians and siliceous sponge fragments. Arrhenius (1963) reported high barium contents associated with the spines of acantharid radiolaria. Goldberg and Arrhenius (1958) believed that the barium/titanium ratio may be an index of organic productivity in the euphotic zone; however, barium relative to titanium is much less abundant than in deep sea pelagic sediment. Emery (1960) noted that in the continental borderland the barium/titanium ratios increase continuously seaward which is inversely proportion al to both productivity of surface waters and rate of depo sition of detrital sediments. Although the curve relating barium/potassium to percentage of potassium (Fig. 56) has a broad spread in the lower range of potassium, there is a general linear tendency with a slight suggestion towards inverse relationships. The plot of barium/sodium + potas sium versus sodium + potassium (Fig. 57) exhibits a linear relationship indicating that sodium + potassium controls the barium content, which suggests that illite controls the barium content. Based upon the assumption that barium ra tios plotted against potassium and sodium are taken to indi cate variations with illite and montmorillonite, it appears . 168 • -HI • • • • % * * -9 9 4 ■ ( ► • • • • ■ • # t • • • • • • • • • • • • • » • • ► » 1 1 1 1 > 1 2 3 PERCENT K 1 1 1 I t 1 1 <D N 0 A t HI N sOlKX/og iN30W3d VARIATION IN THE RATIO OF TOTAL BARIUM TO TOTAL POTASSIUM WITH PERCENTAGE OF TOTAL POTASSIUM FIGURE 56 9 8 - 7 - w & O 6’ ¥ 5' o o 4 CD4 U 3 QC 2- I - • • I 3 T i 6 4 5 PERCENT (No+K) i 7 I 8 V t 9 VARIATION IN THE RATIO OF TOTAL BARIUM TO TOTAL SODIUM PLUS POTASSIUM WITH PERCENTAGE OF TOTAL SODIUM PLUS POTASSIUM FIGURE 57 that these clays may be a major factor controlling the bar- ium concentrations within the basin system. However, the great variation in barium/potassium and barium/sodium + potassium ratios suggests that other factors are also opera-* tive. The highest contents for barium occur along the western margin of the basin, suggesting a possibly more recent source of magmatic activity than along the eastern margin of the basin. The highest value in the basin system is 0.43 per cent at station N0TS-10 along the San Clemente Rift Zone. The high value of 0.11 per cent at station AHF 8421 along the steep slope of San Clemente Island is probab ly related to a similar origin as postulated for barite concretions reported there by Revelle and Emery (1951). Emery (1960) presumed that baritic solutions emanated from a magmatic source upward along a fault zone and precipitated as concretionary forms in the muds on contact with sulfate- bearing interstitial waters. Boron contents range from 0.0015 per cent to 0.027 per cent and average 0.0049 per cent. Hirst (1962) reported values of 0.0081 per cent for greenish muds and Emery (1960) found boron percentages of 0.028, 0.017, and 0.025 for the Santa Barbara Basin, San Clemente Basin, and the continental slope, respectively. 171 The general trend is for boron to be associated with the clay fractions. The relationship between boron and clays was studied in detail by Harder (1961), who reported that illite absorbs much more boron than either montmorilIonite or kaolinite under the same conditions and further suggested that boron replaces aluminum, proxying for silicon in tetra hedral positions. However, an apparent anomaly exists for stations AHF 8419, NOTS 15 and NOTS 16, in which sediments low in clays have the highest boron percentages of 0.018, 0.015, and 0.027 per cent, respectively. The inconsistency of high boron content with coarse grain size is believed due to the high percentage of glauconite in the sediment. Hirst (1962) reported values of 0.0300 and 0.0155 per cent for some glauconite sands. There is an apparent inverse relationship of the curve in Figure 58 at values of 7 to about 9 per cent aluminum, which indicates additional con trols on boron. However, at about 9 per cent aluminum the curve levels out and the boron/aluminum ratios maintain a steady value of about 2.0 x 104. Nicholls and Loring (1962) used a similar constant ratio to represent the maximum boron/aluminum ratio for aluminum associated boron and, since the ratio apparently remains constant despite varia- % tion in sedimentation rate, it probably represents the 172 8 - 7 - 6- 3 9- 2- I- PERCENT Al VARIATION IN THE RATIO OF TOTAL BORON TO TOTAL ALUMINUM WITH PERCENTAGE OF TOTAL ALUMINUM F IG U R E 5 8 173 maximum detrital boron/aluminum ratio in the degraded clays carried into the basin of deposition. The Santa Catalina Basin contains copper percentages ranging from 0.00095 to 0.012 and averaging 0.00603 per cent. Although the copper/aluminum ratios are not entirely consistent, a general tendency exists which suggests that copper is probably associated mainly with the clays because ratios of copper/aluminum against aluminum are taken to in dicate variations with total clay content? also, it may suggest little variation in sedimentation intensity. A comparison of copper/magnesium and copper/potassium ratios indicates that copper is related to potassium and it appears that copper favors illite as its host mineral. Revelle and others (1955) found a close correlation between the barium and organic contents of Pacific sediments. In the present work, some values of high barium contents are asso ciated with high copper contents, but a definite trend is not established. Wakeel and Riley (1961) reported that a portion of the copper in marine sediments is of biogenous origin and is derived from organic-copper complexes, such as i the respiratory pigment haemocyanin, derived from fish and planktonic debris. A plot of the variation in the ratio of copper to organic carbon with percentage of organic carbon 174 (Fig. 59) suggests an inverse relationship in which at val ues less than about 4 per cent organic carbon other factors control the abundance of copper in the sediment. The average chromium content of the basin system is 0.0192 per cent and ranges from 0.0084 per cent to 0.088 per cent. The highest value is associated with the Emery Sea- knoll (0.088 per cent). Goldberg and Arrhenius have sugges ted that an excess of chromium greater than 0.0100 per cent in sediments is a useful indication of the presence of al tered or unaltered basaltic pyroclastics. Consequently, the presence of exceptionally large amounts of chromium on the Emery Seaknoll may be taken as corroborating evidence for an underlying volcanic structure. An alternate expla nation is that high chromium may be related to a highly oxidizing environment. The average chromium content of greenish muds at the Gulf of Paria is 0.0093 per cent (Hirst, 1962). Emery (1960) reported values of 0.007 per cent and 0.015 per cent for the Santa Barbara Basin and the Santa Catalina Basin, respectively. Steiger (in Clarke, 1920) reported an average chromium content of 0.034 per cent for blue and green muds. The chromium/aluminum ratios are moderately constant, suggesting a degree of association of chromium with the clay fraction. According to Hirst 175 l.3-i . 1.2- • l . l - 1.0- • 0 . 9 - fO O 0 . 8 - i A M u 0 -7 - \ o 0 .6- V. A U 0 . 5 - 0 . 4 - 0 . 3 - 0 . 2 - • \ • • V . • • 0.1- # * 1 , # 1 1 • # • 0 - 1 I I I I I I I I 0 1 2 9 4 5 6 PERCENT O.C. VARIATION IN THE RATIO OF TOTAL COPPER TO ORGANIC CARBON WITH PERCENTAGE OF ORGANIC CARBON FIGURE 59 (1962), chromium probably enters a basin in lattice posi tions within the degraded clays. Frohlich (1960) postulated that the bulk of chromium present in sediments is associated with micas and clays, particularly illite. A comparison of the chromium/magnesium ratios and chromium/potassium ratios indicates no apparent consistency and therefore no conclu sions can be drawn as to whether or not chromium fixation is dominant in montmorillonite or illite. It is probable, how ever, that chromium shows a preference for illite in accord ance with the expected conditions of formation of the illite during weathering. Hirst (1962) reported that illite is formed under rather acid and reducing conditions which pro- bably allow retention of chromium (as Cr ) and its inclu sion in the lattice, and conversely, montmorillonite is formed under oxidizing and alkaline conditions where chro mium may be converted to the anionic complex CrOg- and re moved in solution. The variation in chromium/organic carbon ratios with percentage organic carbon, Figure 60 shows an inverse relationship. Thus, the organic carbon is far from saturated with non-detrital chromium and consequently other processes where largely responsible for the extraction of chromium from solution. Vanadium determinations gave results somewhat higher 177 16- 14- 12- .M t e- 4- 2- 3 9 7 a 2 4 6 PERCENT O. C. VARIATION IN THE RATIO OF TOTAL CHROMIUM TO ORGANIC CARBON WITH PERCENTAGE OF ORGANIC CARBON FIGURE 60 178 than Emery's 0.015 per cent value for the Catalina Basin and quite a bit lower than the average of 0.045 per cent deter mined by Goldberg and Arrhenius (1958) for red clays. The average content of vanadium is 0.0213 per cent and ranges from 0.012 per cent to 0.055 per cent. The highest concen trations of vanadium occur in the southern part of the basin and sure apparently associated with the San Clemente rift zone. Much of the vanadium in marine sediments is probably contained in the clay minerals (Rankama and Sahama, 1950). Ratios of vanadium/aluminum and vanadium/iron suggest a close association with the clays as found by Le Riche (1959) with entry to the basin in lattice positions within the de graded clays. The relatively high chromium/vanadium ratios may indicate a concentration of vanadium relative to chro mium in montmorillonite. According to Hirst (1962), vana dium is preferentially retained during the formation of montmorillonite, whereas chromium prefers illite. There is a general relationship between high values of vanadium with high values of iron and as indicated by Krauskopf (1956) vanadium is fixed by adsorption of vanadium onto F6203 and Fe(0H)3 . Some vanadium may be related to concentration by organic matter and Figure 61 representing the variation of the vanadium/organic carbon ratio with percentage organic 179 9- 8- 7 - e - 5 - i 3- 2- I- PERCENT O.C. VARIATION IN THE RATIO OF TOTAL VANADIUM TO ORGANIC CARBON WITH PERCENTAGE OF ORGANIC CARBON FIGURE «l 180 carbon has an inverse relationship indicating additional processes of concentration sure active for this fraction. Gallium contents vary from 0.0030 per cent to 0.0082 per cent and average 0.0057 per cent. The relatively high average for gallium is in great variance with Hirst's (1962) average value for greenish mud (0.0022 per cent) and the 0.0019 per cent average for Pacific pelagic sediments re ported by Goldberg and Arrhenius (1958). The general con stancy of the gallium/aluminum ratio suggests that gallium enters the basin structurally combined within the lattices of the clay minerals. The gallium/sodium + potassium ratio shows great constancy compared to the gallium/aluminum ratio, suggesting gallium is related more to illite and montmorillonite, assuming that the bulk of sodium and po tassium is in these two clay minerals rather than with the total clay content. Although McLaughlin (1959) held a similar point of view in that the amount of gallium that is diadochic with aluminum in the kaolinite structure is usual ly small, Hirst (1962) found that much of the gallium in the Gulf of Paria Basin sediment may be replacing aluminum in kaolinite. The relationship between gallium/organic carbon and percentage organic carbon, illustrated in Figure 62, demonstrates a tendency towards an inverse relationship. 0 1 v*ro/09 181 16- 12- 10- 6- 4- 2- PERCENT O.C. VARIATION IN THE RATIO OF TOTAL GALLIUM TO ORGANIC CARBON WITH PERCENTAGE OF ORGANIC CARBON * ___________ FI0U6E 62 182 The curve suggests that the ratios become more or less con stant despite variations in gallium content at Ga/O.C. 2.0 x 10 and that there is an association of gallium with or ganic carbon in the Catalina Basin. Niche 1 ranges between 0.0032 per cent and 0.018 per cent and averages 0.0104 per cent, whereas cobalt averages 0.00293 per cent and ranges between 0,0014 and 0.0087 per cent. The average nickel percentage is greater than the 0.0080 per cent usually found in igneous rocks (Sandell and Goldich, 1943), and indicates that nickel is concentrating in the basin. Cobalt is also being concentrated in the sed iments as Sandell and Goldich (1943) reported an average of 0.0023 per cent for igneous rocks, and Carr and Turekian (1961) reported average cobalt percentages of 0.016 per cent for Pacific clays. The general constancy of the nickel/ aluminum and cobalt/aluminum ratios and the relative incon sistency of the nickel/magnesium and cobalt/magnesium ra tios suggest that nickel and cobalt may be related to fac tors other than the montmorillonite content. According to Hirst (1962), magnesium is lost relative to cobalt and nickel during weathering and during the formation of mont morillonite, when magnesium is retained, both cobalt and nickel will be retained also. Furthermore, although cobalt 183 and nickel contents will be higher in sediments containing montmorillonite than those containing illite alone, their ratios to magnesium should be lower. A plot of nickel/ aluminum and cobalt/aluminum ratios against percentage of aluminum (Figs. 63 and 64) shows a tendency towards an in- verse relationship for cobalt and a linear relationship for nickel. There is a significant difference between the two curves, suggesting that the nickel content is controlled at or near the site of weathering by ionic substitution in the clay lattice, whereas other factors may control the cobalt content. Carr and Turekian (1961) suggested that there are two independent sources for cobalt in deep-sea sediments, detrital clays and dissolved materials in the streams feed ing the oceans. The average cobalt/nickel ratio for the basin is 0.282 per cent, which is less than the 0.288 per cent for the average of cobalt/nickel in igneous rocks and indicates that a relatively small amount of cobalt has been lost, therefore suggesting a short distance of transport. Both Hirst (1962) and Butler (1953) found that cobalt was lost relative to nickel in the weathering products of igne ous rocks so that the cobalt/nickel ratio always decreased from rock to clay. In Figures 65 and 66 the ratios of nickel and cobalt to organic carbon are plotted against 1 8 4 12- • / < •“ • • • • 10- • • ■ •• • • • • • A A * _ 9 - < Z 8 - U l § \ • * - j • • • • u c r U J * 7 — • • • • • 6 - • 5 - • • 4 — < i i 1 > 0 .1 0.2 ' 0.3 N i / Al x 10s VARIATION IN THE RATIO OF TOTAL NICKEL TO TO TAL ALUM INUM WITH PERCENTAGE OF TO TA L ALUM INUM FIG URE 63 1 8 5 0.6- 0 .5 - < 0 .3 - 0.2- 0.1- PERCENT AI VARIATION IN THE RATIO OF TOTAL COBALT TO TOTAL ALUMINUM WITH PERCENTAGE OF TOTAL ALUMINUM FIGURE 6 4 \ \ 0.2- 186 PERCENT O.C. VARIATION IN THE RATIO OF TO TAL NICKEL TO ORGANIC CARBON WITH PERCENTAGE OF ORGANIC CARBON FIG U R E 65 187 20- 18- 16- 14- O k 12- • o o o io— o 8 - 6- 4- PERCENT O.C. VARIATION IN THE RATIO OF TOTAL COBALT TO ORGANIC CARBON WITH PERCENTAGE OF ORGANIC CARBON FIGURE 66 188 percentage organic carbon. Both curves indicate an inverse relationship. There is no marked flattening of the curves relating either nickel/organic carbon or cobalt/organic car bon to percentage of organic carbon; consequently, organic matter is only one of the contributing factors controlling these two elements. Furthermore, the organic matter is not saturated with nickel or cobalt. Zirconium contents average 0.00981 per cent and range from 0.0028 per cent to 0.0260 per cent. The Catalina Basin sediments are below both the 0.018 per cent average for Pacific pelagic sediments (Goldberg and Arrhenius, 1958) and the value for Gulf of Paria average of 0.0169 per cent for clays. There is a tendency for high values of zirconium to be associated with sediments containing zircon, but not in all instances. Degenhardt (1957) presented evidence for substitution of aluminum by zirconium in kaolinite, suggest ing that zirconium in solution would enter the lattice of developing montmorillonite. Tin values were determined in only 4 samples and the failure to detect tin in the determination of total trace elements is due to the lack of sensitivity of the spectro- graphic technique employed. Similarly, lead was determined semi-quantitatively for only 2 samples, although it was identified in 6 other samples. Tin values ranged from 0.0000 per cent to 0.0095 per cent and lead percentages varied from 0.0000 to 0.0260. Hirst (1962) believed that both organic carbon and clay mineral adsorption have a con trol on non-detrital tin. A value of 0.0005 per cent tin in the lithosphere was given by Onishi and Sandell (1957). Goldberg and Arrhenius (1958) reported an average value for Pacific pelagic sediments of 0.0150 per cent for lead. FORAMINIFERA Methods A standardized procedure was followed for the labora tory and faunal analyses. Each sample was weighed dry and washed on a 250 mesh (0.061 mm opening) screen. Perchloro- ethylene was then used for separation of the foraminifera and samples were reweighed. Foraminiferal concentrations and residues from the surface and every 30 cm, or where lithologies changed down the cores, were then encapsulated for further studies. Forantiniferal Analyses Surface (0-3 cm) samples from 50 cores, grabs, and dredges were selected in order to establish the total repre sentative fauna. Recent and subrecent faunas in the Santa Catalina Basin System now occur at the surface due to re working. Specimens were mounted and catalogued for future reference and study. 190 X91 Listed in Table 10 are the species of foraminifera identified for the surface interval of the Santa Catalina Basin System. Over 200 species were recognized, of which only about 20 species were stained by the Rose Bengal tech nique. A study was made of the foraminiferal zone in a soft thin lenticular very fine-grained sandy shale on Santa Bar bara Island. This horizon ranges in thickness from several inches to several feet and occurs between an underlying pillow basalt unit and an overlying basaltic agglomerate unit. Over 60 species and 29 genera were identified. The age of the unit is Middle Miocene lower Luisian Stage as identified by the index Valvulineria californica Cushman. A high abundance of Bolivinas and Buliminas suggest an upper bathyal depth. The fauna from interbedded marine strata in the volcanic sequence of the Wilson Cove area, San Clemente Island, was found to be also of Luisian age. Coiling ratios of Globiaerina paehvdarma (Ehrenberg) core AHF 8424 were plotted against depth. Although it is not known with certainty that water temperature is the domi nant controlling characteristic, studies by Bandy (1960) indicate that dextrally coiled species of Globiqerina pachy derms are dominant in tropical and temperate waters, whereas 192 TABLE 10 FORAMINIFERA OF THE SURFACE INTERVAL (0-3 cm) OF THE SANTA CATALINA BASIN SYSTEM, CALIFORNIA Ammodiscus hoeglundi (Uchio) 1960 Ammodiscus pacificus Cushman and Valentine 1930 Angulogerina angulosa (Williamson) 1858 Angulogerina baggi (Galloway and Wissler) 1927 Angulogerina carinata Cushman 1927 Angulogerina semitrigona Galloway and Wissler 1927 Astacolus planatus (Galloway and Wissler) 1927 Biorbulina (?) sp. Bolivina advena Cushman 1925 Bolivina argentea Cushman 1926 Bolivina bradyi Asano 1938 Bolivina brevior Cushman 1925 Bolivina californica Cushman 1925 Bolivina decussata Brady 1881 Bolivina instabile Cushman and McCulloch 1942 Bolivina pacifica Cushman and McCulloch 1942 Bolivina pseudobeyrichi Cushman 1926 Bolivina pseudoplicata Heron-Alien and Earland 1930 Bolivina pseudospissa Kleinpell 1938 Bolivina seminuda Cushman 1911 Bolivina seminuda humilis Cushman and McCulloch 1942 Bolivina cuneata (Hofker) 1951 Bolivina subadvena spissa Cushman 1926 Bolivina subadvena acuminata Natland 1938 Bolivina tongi Cushman 1929 Bolivina vaughani Natland 1938 Bolivinita minuta (Natland) 1938 Bulimina barbata Cushman 1927 Buliroina inflata mexicana Cushman 1922 Bulimina marginata denudata Cushman and Parker 1938 Bulimina pagoda Cushman 1927 Bulimina subacuminata Cushman and R. E. Stewart 1930 Buliminella elegantissima (d'Orbigny) 1839 Buliminella subfusiformis tenuata Cushman 1927 Carpentaria balaniformis Gray 1858 Cassidella bramletti (Galloway and Morrey) 1929 Cassidulina bradshawi Uchio 1960 Cassidulina braziliensis Cushman 1922 Cassidulina californica Cushman and Hughes 1925 Cassidulina corbyi Cushman and Hughes 1925 Cassidulina cushmani R. E. and K. C. Stewart 1930 Cassidulina delicata Cushman 1927 Cassidulina limbata Cushman and Hughes 1925 Cassidulina lomitensis Galloway and Wissler 1927 Cassidulina neocarinata Thalmann 1950 Cassidulina norcrossi Cushman 1933 Cassidulina subglobosa Brady 1881 Cassidulina tortuosa Cushman and Hughes 1925 Cassidulina sp. Cassidulinoides bradyi (Norman) 1881 Cassidulinoides waltoni Uchio 1960 Chilostomella ovoidea Reuss 1850 Cibicides conoideus Galloway and Wissler 1927 194 Cibicldes fletcherl Galloway and Wissler 1927 Cibicldes galloway! Cushman and Valentine 1931 Cibicldes lobatula (Walker and Jacob) 1798 Cibicldes mckannai Galloway and Wissler 1927 Cibicldes spiralis Natland 1938 Cibicldes wuellerstorfi (Schwager) 1866 Cornuspira (?) sp. Cribrogoesella pacifica Cushman and McCulloch 1939 Cribrostomoides subglobosum (Cushman) 1910 Cyclammina pus ilia Brady 1881 Cyclammina pus 11 la Brady 1881 variant Dentalina cocoaensis (Cushman) 1925 Dentalina communis (d'Orbigny) 1826 Dentalina decepta (Bagg) 1912 Discorbis orbicularis (Terquem) 1876 Discorbis translucens Ear land 1934 Dyocibicides biserialis Cushman and Valentine 1930 Eggerella advena (Cushman) 1922 Eggerella pus ilia (Goes) 1896 Ehrenbergina bradyi Cushman 1922 Ehrehbergina compressa Cushman 1927 Eilohedra levicula (Resig) 1958 Elphidium articulatum rugulosum Cushman and Wickenden 1929 Elphidium crispum (Linne) 1758 Elphidium hughesi Cushman and Grant 1927 Epistominella exigua (Brady) 1884 Epistominella pacifica (Cushman) 1927 Epistominella smith! (R. E. and K. C. Stewart) 1930 Epistominella subperuviana (Cushman) 1926 195 Eponides repandus (Fichtel and Moll) 1798 Fissurlna luclda (Williamson) 1848 Fissurina obscurocostata Galloway and Wissler 1927 Fissurina orbignyana Sequenza 1862 Fissurina siciliensis Loeblich and Tappan 1954 Fissurina spp. Gaudryina arenaria (Galloway and Wissler) 1927 Glabratella lauriei (Heron-Alien and Earland) 1924 Globigerina bulloides d'Orbigny 1826 Globigerina bulloides quadrilatera Galloway and Wissler 1927 Globigerina hexagona Natland 1938 Globigerina inflata d'Orbigny 1839 Globigerina pachyderma (Ehrenberg) 1861 Globigerina quinqueloba Natland 1938 Globigerina quinqueloba variety Globigerina subcretecea Lomnicki 1901 Globigerinita humilis (Brady) 1884 Globigerinita uvula (Ehrenberg) 1861 Globigerinoides rubra (d'Orbigny) 1839 Globigerinoides sacculifera (Brady) 1877 Globigerinoides aff. triloba (Reuss) 1850 Globobulimina ovata (d'Orbigny) 1846 Globobulimina pacifica Cushman 1927 Globoquadrina eggeri (Rhumbler) 1901 Globorotalia hirsuta (d'Orbigny) 1839 Globorotalia scitula (Brady) 1882 Globorotalia truncatulinoides (d'Orbigny) 1839 Glomospira gordialis (Jones and Parker) 1860 Guttulina quinquecosta Cushman and Ozawa 1930 Gyroidina altiformis (R. E. and K. C. Stewart) 1930 Gyroidlna healdl (R. E. and K. C. Stewart) 1930 Gyroidina subtener (Galloway and Wissler) 1927 Haplophragmoides columbiense evolutum Cushman and McCulloch 1939 Hanzawaia sp, Hoeglundina elegans (d'Orbigny) 1826 Hyperanunina sp. Lagena acuticosta Reuss 1862 Lagena alcocki White 1956 Lagena catenulata (Williamson) 1848 Lagena dentaliformis Bagg 1912 Lagena distoma Parker and Jones 1864 Lagena gracilis Williamson 1848 Lagena hexagona (Williamson) 1848 Lagena laevis (Montagu) 1803 Lagena lineata (Williamson) 1848 Lagena semistriata Williamson 1848 Lagena sesquistriata Bagg 1912 Lagena signoidella Cushman 1933 Lagena striata (d'Orbigny) variants Lagena striatopunctata Parker and Jones 1865 Lagena sulcata (Walker and Jacobs) 1798 Lagena tricarinata (Parr) 1950 Lagena spp. Laticarinina pauperata (Parker and Jones) 1865 Melonis pomplioides (Fichte1 and Moll) 1798 Milionella circularis (Bornemann) 1855 Nonionella scapha (Fichtel and Moll) 1798 197 Nonionella scapha baslspinata (Cushman and Moyer) 1930 Orbulina universa d'Orbigny 1838. Oolina sp. Parafissurina sp. Patellina corrugata Williamson 1858 Planorbulina mediterranensis d'Orbigny 1826 Planulina ariminensis d'Orbigny 1826 Planulina ornata (d'Orbigny) 1839 Polymorphina charlottensis Cushman 1925 Polymorphina frondiculariformis Galloway and Wissler 1927 Polymorphina gibba d'Orbigny 1826 Pullenia Salisbury! R. E. and K. C. Stewart 1930 Pyrgo elongata (d'Orbigny) 1826 Pyrgo ringens (Lamarck) 1804 Quinqueloculina akneriana d'Orbigny 1846 Quinqueloculina angularis d'Orbigny 1905 Quinqueloculina angulo-striata Cushman and Valentine 1930 Quinqueloculina dutemplei d'Orbigny 1846 Rhabdammina sp. Reophaxdentaliniformis (Brady) 1881 Robertinoides charlottensis (Cushman) 1925 Robulus cultratus (Montfort) 1808 Robulus sp. Rotorbinella campanulata (Galloway and Wissler) 1927 Rotorbinella versiformis (Bandy) 1953 Rupertia sp, Saracenaria beali (Cushman) 1934 Sigmoilina tenuis (Czjzek) 1848 Siphogaudryina nuciformis Kleinpell 1938 I 198 Spirillina vivipara Ehrenberg 1843 Splroloculina sp, Stalnforthla schreibersiana complanata Egger 1893 Triloculina trlgonula (Lamarck) 1804 Trochammina charlottensis Cushman 1925 Trochammina pacifica simplissima Cushman and McCulloch 1939 Uvigerina auberina d'Orbigny 1839 Uvigerina hispida Schwager 1866 Uvigerina juncea Cushman and Todd 1941 Uvigerina peregrina Cushman 1923 Uvigerina peregrina hispido-costata Cushman and Todd 1925 Uvigerina senticosa Cushman 1927 Uvigerina subperegrina Cushman and Kleinpell 1934 Valvulineria auracana (d'Orbigny) 1839 Valvulineria inaequalis (d'Orbigny) 1839 species from Arctic waters sure sinistrally coiled (Green, 1958). Bradshaw (1959) established the southern limit of living sinistrally-coiled Globigerina pachvderma. which is indicative of cold waters (Subarctic) faunas, in the Pacific Ocean at 40° N. latitude. There is a positive correlation on a regional basis between cool water masses and sinistral coiling (Ericson, 1959; Ewing and Donn, 1960). There is also a correlation between coiling directions of Globigerina pachvderma and climatic changes during Late Pleistocene and Recent time in the eastern Pacific area. Bandy (1960) has shown, based on radiocarbon dates, that the coiling direc tion of Globigerina pachvderma from Continental Borderland cores changed from sinistral to dextral approximately 12.000 years B. P. This date is about midway between the 15.000 to 7,000 year dates as determined by Curray (1961) for the period of rapidly rising sea level and warming cli mate at the close of the Wisconsin glacial stage. Conse quently, in this area during the Late Pleistocene and Recent dominantly dextrally-coiled tests reflected warm periods, while tests were sinistrally coiled during cold climates. Globigerina pachvderma tests in the upper 260 cm of core AHF 8424 are distinctly dextrally-coiled and show a trend toward sinistrality at about 280 cm. They are 200 approximately 50 per cent sinistrally-coiled at 300 cm and appear to remain so throughout the lower part of the core to 410 cm. The striking similarity between Globigerina pachv derma coiling ratios of core AHF 8424 and Bandy's (1960) core AHF 4704 strongly suggests a time correlation between these cores. Using and extrapolating the radiocarbon dates and coiling ratios given by Bandy (1960) and Emery (1960) for core AHF 4704 and assuming continuous sedimentation, the uncorrected rate of sedimentation for the core is 2.5 cm/100 years. A continuation of the coiling ratio study in this basin, as well as in others, could lead to a useful horizon which might be contoured. An isopachus map of the pre-Recent to post-glacial interval may be constructed and relative rates of sedimentation in the basin determined. CONCLUSIONS The following conclusions are made on the basis of the Catalina Basin study: 1. Extensive faulting largely determined the present shape of the Santa Catalina Basin. The presence of steep, straight escarpments bordering the closed flat-floored Santa Catalina Basin presumably rep resent fault scarps. As a result of geophysical, stratigraphic, and electrosonic profiler data, the basin is interpreted as a fault trough. Over 1800 meters of apparent relative vertical displacement is indicated by "Franciscan-type" schists on Santa Catalina Island. v 2. Earthquake epicenters aligned along the San Cle mente fault zone suggests that active deformation is presently occurring in the offshore area. Faulting is still proceeding along the western margin of the basin in response to local stresses whereas the eastern margin appears to be momentary ly relatively stable. Electrosonic profiler data across the basin reveal that faults, folds, and unconformities are clearly evident, suggesting a structural evolution similar to the onshore area. The combination of these potential structural petroleum traps, reservoir rocks and known oil seeps along the Northern Cata lina Ridge indicates that the Santa Catalina Basin as well as other offshore basins may be sites of important future oil production. Although no vesiculation studies were made, a Mid dle Miocene foraminiferal unit interbedded with submarine pillow basalts on Santa Barbara Island suggests that the bulk of the island formed probab ly at bathyal depths. Uplift of this island block occurred not earlier than post-Middle Miocene Luisian time. Fathograms reveal the presence of irregular hum mocky topography both along the western flank of the Emery Seaknoll and at the base of the San Cle mente Escarpment. These possible submarine land- i slide features may have been triggered by eearthquakes associated with the San Clemente fault ; zone. Although not readily apparent from the fathograms, but suggested by bottom photographs, some slopes on the Emery Seaknoll and the San Cle mente Escarpment may exceed 45°. Currents measured at 180 meters along the northeast side of San Clemente Island had velocities of 3 cm/sec. Continuous sound velocity, temperature and pressure data obtained from a Ramsey Probe revealed no anomalous temperature inversions for the basin and also that a possible northwest-trending "sound channel" may occur along parts of the axis of the basin. Andesite autobreccia dredged from the Emery Sea knoll indicated this bathymetric high is probably a submarine volcano. Similarity of composition with nearby San Clemente Island andesites suggest a Middle Miocene age for this structure. Dark- colored phosphorite, probably Middle to early Late Miocene in age, dredged from the seaknoll surface substantiates an upper limit of time of formation as Late Miocene. | Living organisms are prevalent on the sea floor. j 204 i Some of ihese animals are mud-ingesting, which in- ; dicates that mixing occurs in the surface sediment to an undetermined depth. These organisms may account for the apparent monotonous unbedded se quences found in cores. On the other hand, X- radiographs not only revealed latent structures such as bedding and mottling not visible in re flected light but also resolved in greater detail structures apparent in reflected light. 9. Sediment distribution is fairly regular; however, a distinction occurs between the coarser-grained sediments on or adjacent to topographic highs and the finer-grained basinal sediments. 10. The coarse fraction of the surface interval (0-3 cm) consists of calcareous foraminifera, minor amounts of sand, and occasional diatoms and radio- larians. Coarse fraction analyses showed that foraminifera increase in abundance with both in creasing and decreasing percentages of sand from the 40 per cent sand interval. Higher values in finer sand grades is due to an abundance of plank- tonic foraminifera while high values in the coarser| i i sand grades is a result of a concentration in 205 ; benthonic foraminifera. Diatoms and radiolarians are most abundant in the finer grade sediment. i Allogenic phosphorite and glauconite in the sands have been displaced from bathymetric highs. Abun dant fecal pellets in the silty-clays indicate mixing of the bottom sediment by bottom-dwelling organisms. 11. Clayey silt is the dominant sediment mode in the basin system. A V-shaped distribution curve for I I plots of mean grain size with standard deviation shows that the best sorting occurs at about a mean diameter of 0.18 mm. Basin flat sediments are dominantly negatively skewed, indicating a multiple source in that coarse-grained sediment is being added to an otherwise normally fine-grained sedi ment distribution. The coarse material is an ad mixture of biogenous and terrigenous components in the coarser silt and finer sand grades. Values of kurtosis for the finer grades are principally leptokurtic, whereas the coarser grades are chiefly mesokurtic to platykurtic, indicating that part of j the sediment was previously sorted in a different environment and was transported more or less 206 | unmodified texturally to the present site of depo- 1 sition. 12. The Recent surface sands reflect the mineralogy of the insular terrain and not the continental en virons . The mineralogy of the sand-sized fraction of the surface sediments reveals that they are mineralogically immature. The composition of the unstable heavy fraction and associated light frac tion indicates that the rocks of the islands and submarine highs are the principal source for the sands. 13. The abundance of relatively low stability minerals such as markedly fresh orthopyroxene and hornblende from the surrounding islands and submarine highs reflects a first cycle deposit. Orthopyroxene with: an average composition of hypersthene is the most abundant non-opaque heavy mineral. This assemblage is modified by minor amounts of highly stable groups such as chlorite-epidote, glaucophane- actinolite, muscovite-garnet, and zircon-tourmaline whose source is the metamorphics of Santa Catalina j Island and the Santa Catalina Ridge. The extremelyj low content of alterites as compared with the i 207 i i relatively high values in the mainland coastal area corroborates the conclusion that the sands of the surface interval were derived from the surrounding islands and ridges. Unaltered magnetite in the surface sediments suggests that oxidizing condi tions occur in most parts of the basin. The un usual abundance of plagioclase and lack of potash feldspar indicates a relatively basic igneous source and supports the conclusion that most of the surface sand is derived from local highs. 14. Previous X-ray clay mineral analyses for the basin revealed considerable difference in results. II- lite was found to be dominant in earlier works; however, this study indicates that montmorilIonite is the dominant clay mineral, with moderate amounts of illite and minor quantities of kaolinite. The reason for these discrepancies is due to different preparation techniques and methods of interpreta tion. A standardized technique utilizing porcelain slides for dispersed samples of <31m and using a form factor of 4 for montmorillonite yielded the most accurate and precise results. Low values for ; } illite and kaolinite in the <2|i fraction are due to! 208 | possible differential flocculation near shore and ■ possible size fractionation in the preparation technique. Consequently, if the >2p. and <31j j l frac tion are not included in the analyses, results are inaccurate and lower values of illite and kaolinite result. 15. Although montmorillonite probably has a composite origin in deep-sea sediment, being either the product of alteration of indigenous volcanic mater ial or transported detritus from continents, the relatively high abundance of montmorillonite in the Catalina Basin surface sediment is believed to be continental detritus. The absence in the area of known Recent volcanism, glass shards, and phillip- site in the sediment strongly support this view. 16. A comparison of quartz: feldspar ratios in the <62|i and >62|i fractions indicated that the quartz con tent is greater by a factor of about 4 in the coarser fraction, suggesting different sources for the quartz. 17. Calcium carbonate averaged 18.8 per cent for the basin and scattergrams of calcium carbonate content; plotted against median diameters show a tendency 209 j i towards concentration in the finer grain sizes, probably reflecting comminuted shell and foramini- i feral detritus or small foraminifera. 18. Nitrogen content increased with decreasing grain size and averaged 0.321 per cent. The average C/N ratio is 9.5. Organic matter contents are higher in the finer-grained sediment and average 5.7 per cent for the basin system. 19. Semiquantitative spectrochemical analyses on bulk i samples indicate that the distribution of the major elements (Si, Al, Fe, Na, K, Mg, and Ti) is appar ently primarily controlled by the clay mineralogy of the sediments rather than by the physical con ditions of deposition. Minor elements (Sr, Mn, Ba, B, Cu, Cr, V, Ga, Ni, Co, Zr, Sn, and Pb) analyses : suggest a complex mode of introduction into the basin of deposition. Most probably entered the basin combined structurally in the lattices of clay minerals as evidenced by the relative constancy of i the elementsAl ratios and by other detritals such as zircon. Some elements seem in part controlled by the organic content. Other processes may also j i be operative. j 210 j i 20. About 200 species of foraminifera occur in the 0-3 j cm surface interval, of which 20 species are living forms. 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America, v. 37, p. 107-157, 217-256. Woodford, A. 0., Schoellhamer, J. E., Vedder, J. G., and Yerkes, R. F., 1954, Geology of the Los Angeles basin, chap. II, p. 65-81 in Jahns, R. H., editor, Geology of southern California: Calif. Div. Mines Bull. 170, 876 p. APPENDIXES APPENDIX A Continuous Sound Velocity, Temperature, and Depth Data for the Santa Catalina Basin Area, California (Data Reduction by R. Gaal, 1964) STATION NO. 2 D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 4.5 1509 17.51 309.4 1483 7.91 8.3 (1493)* 17.52- 321.3 1483 7.84 15.9 1507 16.90 333.4 1483 7.71 24.5 1506 16.45 347.3 1483 7.59 33.7 1501 15.53 356.1 1483 7.52 43.7 1494 12.70 360.5 1483 7.49 51.0 1492 11.98 376.9 1483 7.46 55.6 1491 11.37 391.4 1482 7.22 58.1 — — 403.6 1482 7.08 65.8 1490 11.03 409.8 1482 7.02 75.7 1489 10.58 411.7 1482 6.99 84.1 1488 10.26 422.2 1482 6.98 „ 92.8 1487 10.07 434.2 1481 6.89 99.4 1487 9.83 444.6 1481 6.79 104.3 1487 9.74 455.6 1481 6.70 105.8 1487 9.71 462.7 1481 6.60 114.9 1451 (9.72) 478.4 1481 6.50 130.1 1486 9.55 490.7 1480 6.41 144.7 1486 9.42 502.5 1480 6.32 156.7 1486 9.25 512.1 1480 6.23 163.4 1486 9.24 514.8 1480 6.20 174.7 1486 9.12 533.4 1480 6.15 187.2 1485 9.04 547.5 1480 6.09 200.4 1485 8.89 560.2 1480 6.03 207.0 1485 8.76 565.6 1480 5.92 227.2 1485 8.67 566.0 1480 5.90 242.8 1484 8.54 575.6 1479 5.88 254.3 1484 8.38 590.0 1479 5.80 258.3 1484 8.33 603.0 (n.g.) 5.73 272.3 1484 8.20 614.0 1479 5.67 285.0 1484 8.12 617.2 1479 5.64 298.4 1484 8.01 639.4 1479 5.54 306.4 1484 7.95 651.2 1479 5.48 224 225 STATION NO. 2— Continued D(M) SV(M/S) T(°C) 662.2 1480 5.43 668.5 1480 5.38 675.8 (n.g.) (5.37) 687.3 1480 5.32 698.5 1479 5.26 709.5 1479 5.23 718.0 1479 5.21 720.5 1479 5.19 ♦Questionable data in parentheses. 226 STATION NO. 4 D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 1.3 1509 17.53 251.6 1484 8.43 2.3 1509 17.51 252.0 1484 8.39 4.7 1509 17.50 256.6 1484 8.34 10.8 1508 17.40 257.5 1484 8.28 17.2 1497 14.15 261.7 (n.g.) 8.21 24.2 1495 12.93 270.9 1484 8.16 32.0 1492 11.95 280.6 1483 8.04 39.1 1492 11.74 289.8 1483 8.03 46.5 (n.g.) 11.60 298.7 1483 7.93 49.4 1492 11.55 303.7 1483 7.90 50.4 1492 11.51 307.4 1483 7.80 52.7 1491 11.48 308.9 1483 7.74 53.3 1491 11.39 312.9 1483 (7.77) 61.2 1490 11.19 320.6 1483 7.69 71.1 1489 10.79 329.2 1482 7.59 82.0 1488 10.49 338.3 1482 7.58 92.9 1488 10.25 347.6 1482 7.29 97.1 1488 10.17 353.8 1482 7.25 104.1 1488 10.03 357.1 1481 7.20 107.0 1488 10.02 359.8 1481 7.11 111.0 1487 9.96 360.1 1481 7.06 120.2 1487 9.77 370.7 1481 7.00 135.2 1486 9.49 383.3 1482 (7.01) 144.2 1486 9.43 396.4 1482 (7.22) 147.9 1486 9.42 404.8 1482 (7.08) 151.9 (n.g.) 9.37 410.0 1481 6.97 154.8 1486 9.36 411.7 1481 6.93 168.0 1486 9.22 418.1 1481 6.92 175.3 1486 9.23 427.4 1461 6.88 184.8 1486 9.26 444.4 1481 6.75 193.8 1486 9.15 450.9 1481 6.63 199.3 1486 8.99 456.4 1481 6.58 205.5 1486 8.98 460.1 1481 6.57 212.5 1485 8.92 462.1 1480 6.54 220.3 1485 8.77 233.9 1485 8.60 243.9 1484 8.52 227 STATION NO. 5 D(M) SV(M/S) T(°C) D(M) sv(Vs) T(°C) 0.1 1508 17.06 271.9 1484 8.15 0.7 — 17.04 285.2 1484 8.07 4.4 1508 17.05 295.5 1483 7.99 12.3 1508 17.05 301.2 1483 7.89 20.7 1505 16.95 331.9 1483 7.72 29.4 1494 12.60 341.2 1483 7.63 38.1 1493 12.25 348.7 1483 7.51 46.1 1491 11.56 351.3 1483 7.49 50.8 1490 11.09 366.7 1483 (7.54) 51.4 1490 11.01 380.1 1483 7.43 57.0 1490 10.95 391.6 1482 7.31 65.4 1487 10.64 401.0 1482 7.05 73.7 1488 10.44 408.9 1481 6.99 82.0 1488 10.23 420.3 1481 6.96 90.3 1487 10.03 431.6 1481 6.78 97.5 1487 9.91 441.7 1480 6.68 101.4 1487 9.76 449.2 1480 6.50 110.2 1487 9.69 451.6 1480 6.47 119.4 1486 9.63 466.2 1480 6.36 129.6 1486 9.51 469.4 1480 6.28 139.0 1486 9.45 491.1 1480 6.23 146.7 1486 9.32 500.2 1479 6.15 151.2 1486 9.31 501.5 1479 6.11 158.9 1486 9.30 504.8 1480 6.06 168.7 1486 9.23 540.6 1480 5.99 177.4 1486 9.12 552.1 1480 5.96 187.6 1485 8.95 603.5 1479 5.70 195.9 1485 8.88 631.0 1479 5.59 201.0 1485 8.79 641.5 1479 5.52 209.8 1485 8.76 654.5 1479 5.43 217.5 1484 8.58 671.6 1479 5.34 230.3 1484 8.48 685.7 1479 5.25 240.2 1484 8.39 704.8 1478 5.08 246.9 1484 8.33 715.0 1478 5.07 252.0 1484 8.30 744.8 1478 4.95 256.5 — 8.29 756.5 1478 4.90 266.0 1484 8.25 772.3 1478 4.89 228 STATION NO. 5— Continued D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 787.6 1478 4.83 799.7 1478 4.79 807.7 1478 4.74 827.5 1478 4.67 842.0 1478 4.62 854.5 1478 4.55 858.1 1478 4.53 879.0 1478 4.49 890.1 1478 4.45 900.1 1478 4.43 908.9 1478 4.40 914.7 1479 4.39 927.5 1478 4.36 941.7 1479 4.31 953.9 1479 4.29 958.9 1479 4.28 971.4 1479 4.27 983.6 1479 4.25 996.5 1479 4.24 1006.9 1479 4.22 1009.5 1479 4.21 1013.5 — 4.22 1023.3 1780 4.22 1033.8 1480 4.21 1044.3 1480 4.20 1053.3 1480 4.19 1060.0 1480 4.18 1075.1 1480 4.17 1086.6 1480 4.16 1091.7 1481 4.13 1110.7 1481 4.13 2 2 9 STATION NO. 6 D(M) SV(M/S) T(°C ) D(M) sv(Vs> T(°C] 0.1 1510 17.72 329.1 1483 7.70 0.6 — 17.71 340.7 1483 7.51 5.8 1510 17.69 352.8 1482 7.34 14.3 1510 17.68 364.8 1482 7.23 25.0 1505 16.87 376.9 1482 7.20 33.9 1498 14.37 388.8 1482 7.12 41.8 1494 12.49 400.5 1482 7.18 48.3 1494 12.33 411.6 1481 6.86 50.2 1494 12.11 424.2 1481 6.75 56.4 1492 11.84 435.4 1481 6.71 66.0 1490 11.03 447.6 1480 6.49 74.2 1488 10.52 459.1 1480 6.39 84.5 1488 10.16 470.8 1480 6.32 94.3 1487 9.88 482.9 1480 6.33 99.2 1487 9.82 494.7 1480 6.33 100.5 1487 9.78 506 .3 1480 6.27 106.0 1487 (9.81) 518.3 1480 6.12 125.5 1486 9.58 530.2 1480 6.03 137.9 1486 9.41 541.8 1480 5.96 147.3 1486 9.22 553.6 1480 5.92 151.2 1486 9.18 565.4 1480 5.88 157.7 1485 9.16 577.3 1480 5.83 168.9 1485 8.93 589.7 1480 5.77 180.7 1485 8.78 602.0 1479 5.69 193.4 1484 8.66 614.7 1479 5.63 201.9 1484 8.60 627.3 1479 5.59 202.1 (1485-) 8.60 639.6 1479 5.52 207.0 1484 8.58 652.1 (n.g.) 5.47 218.0 (1485) 8.54 664.0 1479 5.41 231.3 1484 8.40 676.8 1479 5.35 242.4 1484 8.27 688.8 1479 5.29 252.5 1484 8.21 700.8 1479 5.22 258.6 1484 8.21 713.3 1479 5.17 270.4 1483 8.04 725.2 1479 5.31 283.3 1483 7.96 737.6 1479 5.09 295.2 1483 7.87 749.7 1479 5.02 303.5 1483 7.75 762.1 1479 4.96 230 STATION NO. 6—CQntinttfid D(M) SV(M/S) T(OC) D(M) SV(M/S) T(°C) 774.1 1479 4.91 786.6 1479 4.85 798.5 1479 4.81 810.5 1479 4.77 822.3 1479 4.70 834.5 1479 4.64 846.7 1479 4.59 859.2 1479 4.55 871.8 1479 4.52 884.8 1479 4.47 897.3 1479 4.43 908.5 1479 4.41 919.8 1479 4.38 931.9 1479 4.35 943.4 (n.g.) 4.31 954.8 1479 4.27 966.2 1479 4.24 977.4 1479 4.23 989.5 1479 4.21 1002.5 (n.g.) 4.19 1015.2 1480 4.17 1027.7 1480 4.16 1052.7 1480 4.14 1065.3 1480 4.12 1077.8 1480 4.11 1090.7 1480 4.10 1103.3 1481 4.09 1116.3 1481 4.08 1129 .4 1481 4.08 1142.5 1481 4.07 1155.2 1481 4.07 1161.9 1481 4.06 1162.8 1481 4.06 1163.0 1481 4.06 231 STATION NO. 7 D(M) SV(M/S) T(°C) 0.2 1.3 2.3 2.4 5.8 17.1 30.2 48.6 57.0 71.8 82.0 97.6 110.6 127.6 139.3 154.7 167.2 185.0 203.2 221.3 237.5 255.9 268.8 288.1 304.8 321.7 339.8 358.4 376.1 392.0 406.1 1263 1509 1509 1509 1509 1508 1498 1493 1490 1490 1488 1488 1486 1485 1485 1485 1484 1484 1484 1484 1483 (n.g.) 1483 1483 1483 1482 1482 1481 1481 1480 1480 18.07 17.41 17.38 17.43 17.47 17.28 14.19 12.28 11.26 10.98 10.57 10.22 9.83 9.46 9.20 8.99 8.78 8.50 8.38 8.28 8.19 7.94 7.84 7.69 7.63 7.49 7.31 7.14 6.89 6.79 6.71 232 STATION NO. 8 D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C 2.9 1510 17.65 387.3 1481 7.08 6.0 1510 17.65 396.4 1481 6.94 9.9 1510 17.65 408.9 1481 6.88 14.2 1510 17.58 417.1 1481 6.81 18.8 1510 17.54 426.5 1480 6.62 25.2 1506 17.36 435.1 1480 6.41 33.4 1500 14.65 444.8 1480 6.45 44.1 1495 13.39 455.3 1480 6.37 54.8 1492 11.91 467.2 (n.g.) 6.31 64.8 1490 11.32 478.6 1480 6.25 73.5 1489 10.79 488.2 1480 6.20 83.8 (n.g.) 10.52 497.5 1480 6.13 90.7 1488 10.22 507.4 1480 6.09 91.3 1488 10.11 517.3 1480 6.05 100.4 1487 9.97 526.3 1479 5.99 111.3 1486 9.58 535.8 1480- 5.96 122.0 1486 9.39 545.8 1479 5.92 132.7 1485 9.21 554.7 1479 5.88 146.4 1485 9.00 563.2 1480- 5.87 159.0 (1484) 8.79 572.4 1480- 5.85 172.4 1485 8.74 581.9 1479 5.78 187.3 1485 8.68 590.9 1479 5.77 199.5 1485 8.70 601.1 1479 5.71 214.5 1484 8.49 610.9 1479 5.67 233.5 1484 8.25 621.6 1479 5.63 247.5 1483 8.16 631.7 1479 5.59 261.5 1483 7.83 641.7 1479 5.54 280.5 1482 7.74 651.8 1479 5.48 294.1 1482 7.55 662.0 1479 5.43 306.8 1482 7.40 672.1 1479 5.39 317.4 1482 7.42 682.4 1479 5.37 328.5 1482 7.33 691.6 1479 5.34 337.6 1482 7.39 700.8 1479 5.30 348.3 1482 7.39 709.6 1479 5.25 359.0 1482 7.35 718.7 1479 5.20 369.5 1482 7.25 727.7 1479 5.17 378.9 (n.g.) 7.23 736.5 1479 5.13 233 STATION NO. 8— Continued D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 745.4 1479 5.09 754.4 1479 5.08 763.5 1479 5.05 772.6 1479 5.02 781.5 1479 4.99 790.5 1479 4.91 799.3 1479 4.87 808.2 1479 4.83 817.1 1479 4.79 826.0 1479 4.74 834.8 1479 4.68 844.0 1479 4.66 853.1 1479 4.63 862.2 1479 4.60 870.9 1479 4.58 879.7 1479 4.53 888.4 1479 4.52 897.4 (n.g.) 4.51 905.2 1479 4.48 909.2 1479 4.45 STATION NO. if ro o j u o H o 'C 10 in O' 00 in CM 10 O' 00 H O' 10 rH * o 00 * o 00 p in O p O CO in O ro O' O' 0 * ro OJ o 00 p ID in in in ro CM CM rH H rH O o O' O' O' 00 00 00 00 p p io m in if ro ro • • • • 9 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • £* p p p p ID vO ID id 10 10 10 10 10 10 10 10 VO 10 10 in in in in in in in in in in in in in in in W \ • OJ rH rH O o O o o o o o O' O' O' O' ot O' O' O' O' O' O' o O' O' o 9 O' O' o O' O' O' s O'00 00 00 00 00 00 00 00 00 00 00 p p p p p p p p p p 00 p p 00 O' P p p p p p* • If If If ' O ' Tf - < f If * if If * * * * • if > c «H •H I —1H rH rH rH rH rH rH rH rH rH rH rH H rH rH rH rH rH rH rH rH rH a rH rH rH rH rH rH CO w w m O' p O' 10 O rH H ro 1" 10 CO H 00 rH o CO p if in ro in CM 10 P H ro 00 CO 00 CM in VO • • . • • • * • • * * • * • • • • • • • • • * • • • • • • • • • • • se in in in ro ro in in in 2 if ro if ro If If ro CM CM CM CM CM ro ro ro if If in in 10 in 00 in *• in vO P 00 O' o o CM ro M1in 10 p 00 O' O rH CM ro if in 10 p 00 O' o rH CM ro * in in Q ro ro ro ro ro ro ro if if if if * m in in in in in in in in in 10 10 vO 10 10 10 10 00 ID m iH rH 10 ro p O' CM 00 O' o rH in ID in p ro o o rH 00 10 CM 2J p* o O' CM rH 00 lO u p p p p P OJ O' 00 ro O' CM CM 00 m ro ro ro CM CM o p in ro CM rH o o o p* 00 P> if if o • • * • • • • • • • • • • • • • • « • • • • • • 9 m • • • 9 « • • ■ * • • p p p p p 10 ro C V I rH rH o o o o O' O' O' O' O' O' O' O' O' 00 00 00 00 00 00 00 00 00 p p- P* P P Ei H H H rH rH rH rH •H ■H rH rH rH rH H 10 O O O o o ro 00 if CM rH • O' 00 00 p ID ID ID 10 10 10 10 in it it if If ro CO ro If If ro CO CM CM CM iH iH rH rH rH O O' O' O' O' O' 00 00 00 00 00 00 a> CO CO 00 00 00 00 CO CO 00 00 00 00 00 00 00 00 00 00 00 in in in in in in * * * * * If * * * * If If Hf * If If * * If if H rH rH rH rH rH rH rH rH rH C H rH H rH rH «H rH rH rH rH H rH rH rH H rH rH H rH rH rH H rH rH H CO CM in p 00 O o O' 00 H P ^ p O 10 in in 10 H rH CM O' 00 CM CM p O' O oo 10 * 00 10 p* P» m O • • • • • • • • • • • • • • • • • • • • • • • • • • 9 • • • • • • • • * • s O in C V J O' P H O' 00 10 in ro CM o O' 00 p 10 ID in ro ro CO ro ro in in 10 P p P» 10 £ in 10 H rH OJ ro it m 10 l * » 00 O' o o rH CM ro <5 in id P 00 O' O rH CM co in 10 p 00 O' o rH CM H rH rH rH rH rH rH rH rH rH rH H CM CM CM CM CM CM CM CM CM CM ro ro ro 235 STATION NO. 10 D(M) SV(M/S) T(°C) D(M) svdv's) T(°C) 0.1 1512 18.52 337.8 1484 7.96 4.8 . 1512 18.51 351.0 1484 7.80 11.7 1512 18.44 361.4 1483 7.35 18.9 1511 18.36 376.4 1483 (7.50) 26.1 1504 16.67 389.5 1483 7.32 33.6 1498 14.03 403.3 1482 7.28 41.6 1498 12.04 415.8 1482 7.14 49.0 1491 11.62 428.4 1482 7.01 57.6 1489 11.00 442.6 1482 6.93 67.0 1489 10.75 456.2 1481 6.81 76.7 1488 10.45 468.0 1481 6.68 86.0 1487 10.13 479.1 1481 6.50 94.5 1487 10.00 492.4 1481 6.42 103.6 1487 9.93 507.1 1480 6.31 113.7 (1488) (10.00) 523.1 1480 6.09 123.1 1487 9.79 537.7 1480 6.05 133.7 1486 9.57 549.1 1480 5.99 143.3 1485 9.13 563.4 1480 5.93 153.9 1487 9.61 575.1 1480 5.90 165.7 1487 9.54 591.4 1480 5.86 178.8 1486 9.15 606.9 1480 5.78 188.6 1486 8.98 622.1 1480 5.73 197.9 1486 8.95 636.0 1480 5.63 205.9 1486 8.87 652.4 (n.g.) 5.60 214.1 1486 8.80 667.1 1480 5.51 220.9 1485 8.78 679.9 1480 5.46 229.9 1486 8.77 695.1 1480 5.41 243.2 1486 8.77 706.8 1480 5.32 253.8 1486 8.70 718.8 1480 5.31 265.8 1486 8.60 731.2 1480 5.25 276.4 1485 8.48 746.5 1480 5.20 287.7 1485 8.38 761.8 1479 5.13 298.1 1485 8.23 778.2 1480- 5.04 306.9 1485 8.19 789.9 1480- 5.02 314.5 1485 8.15 804.7 1479 4.96 324.2 1484 8.00 819.4 1479 4.86 236 STATION NO. 10— Continued D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 835.7 1479 4.81 847.6 1479 4.80 863.7 1480- 4.76 875.9 1479 4.68 890.0 1479 4.61 905.4 1479 4.47 918.5 1479 4.45 934.5 1479 4.38 949.1 1479 4.27 964.6 1479 4.19 977.4 1479 4.15 994.1 1479 4.06 1009.7 1479 4.03 1024.9 1479 4.03 1042.2 1479 4.02 1058.9 (n.g.) 3.95 1076.9 1479 3.83 1090.7 1479 3.77 1105.9 1479 3.75 1123.3 1479 3.73 1137.8 1479 3.70 1154.3 1480 3.70 1168.8 1480 3.67 1179.5 1480 3.63 1186.3 1480 3.61 1187.9 1480 3.61 237 STATION NO. 11 D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C 0.3 1513 18.86 304.1 (1485) 8.38 0.6 1513 18.85 318.9 1486 8.38 1.6 1513 18.85 332.6 1486 8.34 4.3 1513 18.86 347.4 1486 8.26 7.0 1513 18.86 360.8 1485 8.14 9.4 1513 18.79 374.2 1485 7.88 10.0 1513 18.70 386.9 1484 7.77 12.2 1513 18.65 400.9 1484 7.70 16.3 1513 18.63 414.4 1483 7.50 21.8 1504 16.61 427.4 1483 7.24 27.6 1499 14.06 440.2 1482 7.05 34.3 1495 13.11 454.5 1482 6.85 42.0 1493 12.29 469.3 1482 6.78 49.4 1493 12.04 481.3 1481 6.68 59.2 1490 11.18 491.5 1481 6.63 68.5 1490 10.89 499.0 1481 6.55 75.7 1490 10.83 502.5 1481 6.58 85.7 (n.g.) 10.65 506.1 1481 6.56 96.3 1488 10.30 514.1 1481 6.53 106.6 1488 10.06 524.5 1481 6.39 117.6 1488 9.97 534.8 1481 6.29 128.4 1487 9.84 545.7 1481 6.25 137.8 1487 9.75 554.4 1481 6.19 148.0 1487 9.60 562.4 1480 6.12 159.1 1487 9.50 571.1 1480 6.02 168.1 1487 9.48 580.6 1480 5.95 178.5 1487 9.41 590.5 1480 5.88 189.2 1487 9.38 604.0 1480 5.83 199.9 1487 9.34 616.8 1480 5.75 210.2 1487 9.34 630.6 1480 5.69 220.8 1487 9.23 644.5 (1478) 5.63 232.4 1487 9.02 659.9 (n.g.) 5.56 243.6 1486 8.87 674.1 1480 5.51 255.0 1486 8.84 687.5 1480 5.45 267.3 1486 8.74 698.4 1480 5.43 281.9 1486 8.65 702.2 1480 5.36 293.0 1486 8.46 710.4 1480 5.35 238 STATION NO. 11— Continued D(M) SV(M/S) T(°C) D(M) SV(H/S) T(°C) 727.4 1480 5.30 1329.2 1481- 3.29 749.2 1480 5.20 1348.2 1481 3.26 769.6 1480 5.10 1367.7 1481 3.25 789.4 1479 4.99 1385.5 1481 3.19 808.5 1479 4.91 1396.0 1481 3.17 827.8 1479 4.78 1400.8 (n.g.) 3.16 847.6 1479 4.66 1416.7 1481 3.13 866.8 1479 4.54 1434.9 1481 3.11 886.0 1479 4.47 1451.4 1481 3.06 905.2 1479 4.42 1465.6 1481 3.06 924.4 1479 4.29 1479.9 1482- 3.04 943.7 1479 4.23 1492.3 1482 3.03 963.0 1479 4.16 1494.7 1482 3.02 982.3 1479 4.09 1507.7 1482 3.02 1000.2 1479 4.02 1510.0 1482 3.00 1007.3 . .(1478) 4.01 1520.5 1482 2.98 1018.1 1479 3.98 1532.2 1482 2.97 1030.6 1479 3.95 1543.8 1482 2.97 1047.0 1479 3.88 1552.2 1482 2.95 1064.4 1479 3.84 1566.4 1483 2.94 1081.6 1479 3.79 1578.2 1483- 2.93 1098.6 1479 3.74 1588.7 1483 2.91 1115.5 1479 3.66 1592.4 1483 2.90 1132.7 (1478) 3.58 1601.2 1483 (2.91) 1148.3 1479 3.55 1612.7 1483 2.90 1164.6 1479 3.56 1628.4 1483 2.88 1177.5 1479 3.54 1642.0 1483 2.87 1188.9 1479 3.55 1655.4 1484 (2.88) 1197.4 1479 3.51 1669.6 1484 2.86 1198.3 1479 3.50 1681.7 (n.g.) 2.86 1201.9 1479 3.50 1690.0 1484 2.86 1215.4 1479 3.47 1691.0 1484 2.85 1233.1 1480 3.47 1699.8 1484 (2.86) 1252.5 1480 3.41 1710.6 1484 2.85 1271.4 1480 3.38 1724.4 1485 2.85 1290.6 1480 3.34 1737.8 1485 2.85 1310.2 1480 3.32 1753.2 1485 2.84 239 STATION NO. 11— Continued D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 1765.7 1485 2.83 1776.5 1485 2.83 1789.3 1486 2.82 1802.3 1486 2.83 1812.4 1486 2.82 1822.7 (n.g.) (2.83) 1833.0 1486 2.82 1839.6 1486 2.82 1844.3 1486 2.82 1851.7 1487- 2.82 1862.0 1487 2.82 1875.4 1487 2.82 1886.1 1487 2.82 1891.5 1487 2.81 1896.9 1487 2.81 1097.3 1487 2.81 1917.3 1488- 2.82 1922.4 1488- 2.81 1936.2 1488 2.82 1942.4 1488 2.82 1948.6 1488 2.82 1956.3 1488 2.82 1962.5 1488 2.82 1964.1 1488 2.82 1972.7 1488 2.82 1980.0 1489- 2.83 1989.7 1489 2.83 1993.5 1489 2.84 240 STATION NO. 12 D<M) SV(M/S) T(°C) D(M) SV(M/S) T(°C 6.1 1512 18.33 261.4 (n.g.) 8.38 10.2 1512 18.33 271.8 1484 8.22 . 14.3 1512 16.35 283.3 1484 8.11 19.1 1512 18.34 293.7 1484 7.96 23.3 1512 18.33 302.8 1484 7.94 28.5 1508 18.17 315.5 1483 7.86 34.2 1499 14.24 324.1 1483 7.73 40.3 1494 13.05 333.6 1483 7.56 46.1 1491 11.73 343.0 1482 7.36 53.4 1490 11.35 353.7 1482 7.35 61.1 1490 11.08 365.1 1482 7.26 69.2 1489 10.98 379.1 1482 7.15 80.0 1488 10.70 391.6 1482 7.08 89.2 1487 10.10 402.0 1481 6.97 99.8 1487 9.90 410.7 1481 6.90 110.2 1485 9.70 421.8 1481 6.84 120.6 1485 9.16 434.3 1480 6.68 130.2 1484 9.00 443.1 1480 6.53 139.9 1484 8.91 450.6 1480 6.50 148.7 1484 8.79 455.6 1480 6.48 156.2 1484 8.57 457.9 1480 6.47 164.1 1483 8.58 171.1 1483 8.33 179.6 1484 8.51 189.8 1485 8.81 201.5 1485 8.85 210.8 1485 8.59 219.0 1485 8.55 226.8 1484 8.45 236.2 1485 8.54 248.5 1485 8.46 241 STATION NO. 13 D(M) sv(m/s ) T(°C) 0.1 1511 18.23 6.1 (n.g.) 18.22 27.0 1511 18.17 40.3 1505 16.77 54.9 1496 13.52 71.2 1491 11.71 80.4 1491 11.14 87.0 1489 10.83 96.3 1489 10.48 105.9 1489 10.14 121.3 1487 9.90 139.6 1486 9.57 146.8 1486 9.34 153.4 1486 9.29 171.7 1486 9.22 186.0 1485 9.11 193.0 1484 8.68 202.0 1484 8.54 207.5 1484 8.52 224.0 1484 8.48 235.4 1485- (8.54) 244.5 1485 8.54 257.5 1485 8.44 267.1 1485 8.40 274.9 1485 8.38 284.5 1485 8.32 295.1 1484 8.27 309.6 (n.g.) 8.07 322.8 1483 7.83 340.0 1483 7.71 350.5 1483 7.67 359.4 1483 7.63 369.7 1483 7.46 384.2 1483 7.38 389.5 1483 7.32 392.2 1483 7.31 242 STATION NO. 15 D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C 1.2 1511 18.12 575.7 1480 5.94 2.6 (n.g.) 18.12 594.3 1480 5.83 6.5 1511 18.12 613.1 1480 5.73 13.5 1511 18.13 631.5 1480 5.68 22.1 1506 17.19 649.9 1480 5.65 31.5 1499 14.71 668.4 1480- 5.50 43.3 1496 13.08 687.3 1479 5.38 55.5 1492 11.91 705.6 1479 5.30 67.1 1491 11.31 724.2 1479 5.22 75.9 1489 10.89 742.7 1479 5.13 93.9 1488 10.35 761.1 1479 5.06 109.2 1486 9.80 779.4 1479 4.99 122.6 1486 9.56 797.9 1479 4.81 135.2 1486 9.46 816.7 1479 4.82 150.1 1486 9.30 834.9 1479 4.74 168.8 1486 9.25 853.3 1479 4.68 186.9 1485 8.79 871.7 1479 4.60 205.1 1484 8.66 890.1 1479 4.51 223.6 1484 8.47 908.4 1479 4.39 241.8 1484 8.27 926.6 1479- 4.31 260.4 1484- 8.15 938.0 1479 4.27 278.9 1483 7.92 297.6 1483 7.82 316.7 1483 7.66 335.1 1483- 7.54 ' 353.3 1482 7.45 371.9 1482 7.30 390.5 1482 7.22 409.0 1481 7.05 427.5 1481 6.84 446.0 1481 6.65 464.4 1481- 6.54 482.9 1481 6.50 501.5 1480 6.29 520.0 1480 6.22 538.8 1480 6.07 557.3 1480 6.03 243 STATION NO. 16 D(M) SV( M/S) T(°C) D(M) SV(M/S) t (°c ; 1.0 1511- 18.01 553.9 1480 6.03 1.1 (n.g.) 17.97 572.2 1480 5.99 4.5 1511- 17.97 590.2 1480 5.86 14.1 1511 17.96 608.7 1480 5.83 26.3 1499 14.84 624.1 1480 5.74 41.0 1494 12.71 640.9 1480 5.62 55.8 1490 11.32 660.1 1480 5.52 71.4 1489 10.67 679.8 1480 5.41 85.7 1488 10.29 699.9 1480 5.35 101.3 1487 9.95 718.6 1480- 5.23 116.8 1487 9.80 737.3 1479 5.15 132.0 1487 9.62 751.0 1479 5.10 149.7 1486 9.49 756.9 1479 5.07 166.3 1486 9.34 182.1 1486 9.22 197.5 1485 9.02 209.8 1485 8.75 223.2 1485 8.62 240.0 1484 8.50 254.6 1484 8.26 273.2 1483 8.03 289.1 1483 7.88 302.0 1483 7.78 314.8 1483 7.74 331.3 1483 7.65 349.8 1483 7.51 368.3 1483 7.39 387.4 1482 7.23 405.9 1481 6.99 424.7 1481 6.77 443.3 1481 6.62 461.6 1481- 6.53 480.2 1480 6.48 498.5 1480 6.23 517.0 1480 6.22 535.3 1480 6.16 244 STATION NO. 17 D(M) SV(M/S) T(°C) D(M) sv(^s) T(°C] 2.9 1508 17.14 459.8 1480 6.49 3.4 (n.g.) 17.09 476.0 1480 6.38 11.7 1508 16.99 491.3 1480 6.25 23.1 1505 16.82 505.8 1479 6.12 37.9 1494 12.57 519.3 1480- 6.09 50.2 1491 11.51 531.7 1480 6.03 61.6 1491 11.30 544.1 1480 6.01 75.8 1490- 10.91 555.2 1480 5.95 90.0 1488 10.51 565.7 1480 5.92 100.4 1488 10.25 575.6 1480 5.90 110.4 1487 9.96 585.0 1480 5.87 119.9 1487 9.69 593.6 1480 5.83 128.7 1487 9.61 602.1 1480 5.79 139.4 1487- 9.53 612.6 1480 5.78 153.1 1486 9.42 626.9 1480 5.70 165.2 1486 9.27 641.5 1480 5.63 176.7 1486 9.11 654.5 1480 5.57 189.0 1486 9.04 667.8 1480 5.50 203.2 1485 8.88 682.1 1479 5.45 218.1 1485- 8.65 693.1 1479 5.37 235.2 1484 8.45 703.0 1479 5.35 251.3 1484 8.31 716.9 1479 5.27 265.0 1484 8.21 729.1 1479 5.24 277.6 1484 8.11 739.6 1479 5.22 288.8 1484 8.03 750.6 1479 5.12 303.3 1484 7.97 761.1 1479 5.03 314.6 1483 7.86 772.0 1479 4.92 324.9 1483 7.75 783.0 1479- 4.86 338.8 1483- 7.59 793.5 1478 4.75 353.1 1482 7.44 804.8 1478 4.68 368.0 1481 7.20 815.3 1478 4.64 382.4 1481 6.97 826.4 1478 4.59 397.4 1481 6.95 836.9 1478 4.54 412.1 1481 6.86 851.4 1478 4.49 427.6 1481 6.86 863.8 1478 4.45 443.2 1481- 6.70 873.6 1478 4.41 245 STATION NO. 17— Continued D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C) 883.3 1478 4.36 892.8 1478 4.34 902.4 1478 4.30 912.2 1478 4.27 922.3 1478 4.24 '933.1 1478 4.22 940.7 1478 4.21 945.3 1478 4.21 947.5 1478 4.19 948.2 1478 4.19 246 STATION NO. 18 D(M) SV(M/S) T(°C) D(M) SV(M/S) T(°C 53.2 1491- 11.34 533.1 1480 6.09 65.5 1489 10.89 545.6 1480 6.02 77.5 1488 10.44 558.9 1480- 5.90 89.6 1487 10.01 574.6 1479 5.85 101.5 1487 9.84 590.2 1479 5.77 125.9 1486 9.56 603.7 1479 5.67 137.7 1486 9.37 616.0 1479 5.63 150.1 1486- 9.21 628.6 1479 5.55 163.3 1486 9.17 641.5 1479 5.48 177.0 1485 9.00 654.8 1479 5.44 190.7 1485 8.96 667.8 1479 5.36 204.6 1485 8.76 681.0 1479 5.29 217.8 1485 8.73 694.1 1479 5.22 231.9 1484 8.59 706.5 1479 5.14 246.5 1484 8.42 720.0 1479- 5.05 260.1 1484 8.27 732.3 1479 4.99 271.5 1485 8.20 745.1 1478 4.85 282.6 1484 8.05 757.2 1478 4.77 296.5 1484- 7.98 770.0 1478 4.73 309.0 1483 7.87 781.3 1478 4.70 320.0 1483 7.72 793.6 1478 4.68 333.2 1483 7.62 805.4 1478 4.65 346.2 1483 7.52 813.6 1478 4.61 357.7 1482 7.44 820.4 1478 4.60 368.9 1482 7.33 827.7 1478 4.60 384.2 1482 7.24 834.2 1478 4.59 398.7 1482 7.10 843.0 1478 4.57 408.9 1481 6.98 851.3 1478 4.50 419.5 1481 6.85 856.2 1478 4.45 434.3 1481 6.79 860.3 1478 4.43 447.4 1481 6.75 459.2 1481 6.64 471.2 1481 6.53 483.5 1480 6.45 496.5 1480 6.35 509.1 1480 6.26 520.6 1480 6.20 247 STATION NO. 19 D(M) SV(M/S) T(°C) (0.8) (1267) (20.20) 1.9 1474 17.11 2.6 1606 16.06 2.7 1505 15.96 3.0 1505 15.98 3.1 1505 15.99 5.1 (n.g.) 16.04 11.0 1505 16.00 19.3 1505 16.03 29.3 1500 14.82 39.2 1494 12.63 48.9 1492 11.84 58.5 1491 11.27 67.8 1490 11.09 76.9 1489 10.71 84.7 1489 10.49 85.9 1488 10.36 86.8 1488 10.25 82.1 1487 9.90 153.2 1487 9.56 159.8 1487 9.56 166.3 1487 9.56 172.9 1486 9.40 182.1 1486 9.26 192.6 1486 9.14 202.7 1486 9.05 205.5 1486 9.14 227.5 1486 9.05 250.4 1484 8.30 (687.2) 1479 (5.55) 696.4 1478 5.12 699.3 1479- 5.12 (872.0) 1478 (5.10) APPENDIX f i Station Locations STATION LOCATIONS Station Latitude Longitude Depth (Meters) Type AHF 8314a 33°22'45"N 118038'27" W 1057.3 Piston Core AHF 8315 33°22'30"N 118°47132"W 1331.4 II II AHF 8316 - 33°17*40"N 118°53,45"W 1333.3 11 ll AHF 8317 33°14'10"N 118037'30" I f 1298.0 II II AHF 8318 33°02'10"N 118°34'54"W 24.7 Dietz-Lafond AHF 8319 33°05138"N 118° 34* 12" W 1227.8 Piston Core AHF 8320 32°55,28"N 118°20,20"W 1260.4 II II AHF 8321 33°07'29MN 118°09'00, , W 1027.3 II II AHF 8418 33°04'00"N 118021*10"W 1134.1 Pipe Dredge AHF 8419 33°02'00"N 118°23,32"W 728.0 II II AHF 8420 33°02*10"N 118°23'45"W 785.0 II II AHF 8421 33°02'13"N 118031*40" W 530.2 II II AHF 8422 33o10'55"N 118°31'55"W 910.0 II II AHF 8423 33°10'55"N 118022'45"W 1184.2 II II AHF 8424 33° 19' 15" N 118°43* 02"W 1314.0 II II AHF 8425 33°26,40"N 118°51'48"W 1242.8 II II Station Latitude Longitude Depth (Meters) Type AHF 8426 33°26,25"N 118o40'00" W 728.0 Biological Dredge AHF 8685 33°06'54"N 118o03'15“W 987.2 Piston Core AHF 8686 33°13'15"N 118°12'15"W 1088.3 II II AHF 8687 33°09'27"N 118014'35”W 1091.7 11 II AHF 8688 33o03*00"N 118°16'35nW 1108.6 II t l AHF 8689 32o50,45"N 118°17'55"W 999.4 II II AHF 8690 32°51'40, , N 118021,57"W 781.5 Gravity Core AHF 8691 32o58*40"N 118°26126"W 1150.9 Piston Core AHF 8692 33°05l55"N 118°24* 30”W 1116.2 II II AHF 8693 32°57'55"N 118°17,50"W 1207.3 Campbell Grab MA-lb 33°21,53"N 119°02,20"W 51.8 Snapper MA-2 33°21'32”N 119°01'10"W 82.3 II MA-3 33°21'5S"N 119°03,20"W 76.2 II NOTS-G-1° 33°15'28, , N 118°24,35"W 1688.8 Phleger Core NOTS-G-2 33°12'42"N H8°30'27"W 1371.4 t l n NOTS-G-3 33°10* 12”N 118o36,00"W 1462.8 II l i N0TS-4A 33°15.4' N 118°16.6' W 386.4 Kullenberg Gravity Core 250 Station Latitude Longitude Depth (Meters) Type N0TS-4B 33°14.2* M 118°19.2' W 1088.3 DOTS-5 33°11.51 M 118°21.3' w 1153.0 NOTS-6 33°05.5* N 118°27.5' w 1157.0 NOTS-7 33°02.4' M 118°32.9' w 505.4 MOTS~8 32°57.71 N 118°28.4' w 1101.3 NOTS-9 32°51'N 118°20.3' w 757.9 NOTS-IO 32°44.6' M 118°12.8' w 1096.6 MOTS'11 32°38.2' M 118°07.2’ w 2024.2 NOTS-14-1 33°01.7' N 118°22.71 w 780.0 MOTS-14-2 33°01.6’ N 118°22.4' w 782.0 MOTS—15 32°55.61 N 118° 16.1' w 1045.8 MOTS-16 33°01'N 118°10.6' w 822.2 NOTS-17 32°05.9' N 118°05.11 w 1013.9 MOTS-18 33°10.3' M 118°01.1' w 918.9 N0TS-18A 33°15’N 118°02.4' w 879.8 MOTS—19 33°21.2' M ii8o02.5' w 739.9 MOTS-34 33°00' 13"'N 118°32107"W 224.9 Kullenberg Gravity Core Gravity Core l\J U l Station Latitude Lon9itude Depth (Meters) Type NOTS-39 33°00‘14"N 118°32,07"W 224.9 Gravity Core NOTS-121 33o00’15"N 118°32,07"W 226.8 M I I NOTS-130 33°00'14"N 118°32'06"W 226.8 I I I I NOTS-143 33°00'15"N 118°32,06"W 230.4 I I I t NCEL-ld 33°19.2' N 118°42.31 W 1317.0 I I I I NCEL-2 33°15.2' N 118°39.0' W 1310.8 I I I I NCEL-3 33°10.7' N iia?36.3' W 1296.5 I I t l NCEL-4 32°56.2* N 118°20.0' W 1243.3 I I I I NCEL-5 32°58.6' N 118°17.4' W 1258.6 I I I I LITTLE HARBOR 32°23.0' N 118°28.51 W Mid Tide Point Grab Sample aAllan Hancock Station Sample ^Marine Advisers Sample CNaval Ordnance Test Station, Pasadena, Sample dNaval Civil Engineering Laboratories, Pt. Hueneme, Sample f O V> r o APPENDIX C Semiquantitative Spectrographic Analyses of the 0-3 cm Surface Interval of Some Santa Catalina Basin Area Cores (Values in Per Cent) 254 Element AHF 8314 AHF 8315 AHF 8316 AHF 8317 Silicon 21.0 22.0 19.0 19.0 Aluminum 8.8 8.8 9.0 11.0 Iron 3.4 4.7 3.3 4.4 Calcium 6.0 5.4 7.0 6.7 Magnesium ^ 4.4 | 3.6 J 3.5 j 3.5 Titanium 0.70 0.62 0.79 i 0.80 Barium 0.096 0.087 0.11 0.086 Boron 0.0021 0.0042 0.0043 0.0053 Lead nil nil nil trace Gallium 0.0057 0.0049 0.0053 0.0073 Manganese 0.042 0.049 0.035 0.041 Chromium 0.023 0.023 0.022 0.017 Nickel 0.012 0.015 0.014 0.013 Vanadium 0.015 0.018 0.017 0.020 Copper 0.0052 0.0070 0.0076 0.011 Sodium 2.6 2.0 3.2 2.4 Zirconium 0.011 0.010 0.0076 0.0095 Cobalt 0.0034 0.0040 0.0032 0.0037 Potassium 2.5 1.3 1.5 1.7 Strontium 0.042 0.036 0.052 0.048 Tin nil nil 255 Element AHF 8318 AHF 8319 AHF 8320 AHF 8321 Silicon 15.0 22.0 15.0 21.0 Aluminum 5.6 8.6 8.7 8.8 Iron 1.6 3.6 3.4 4.8 Calcium 18.0 6.8 9.6 5.1 Magnesium 2.6 3.2 3.9 3.2 Titanium 0.45 0.79 0.86 0.64 Barium nil 0.10 0.095 0.074 Boron 0.0026 0.0064 0.0058 0.0042 Lead nil trace nil trace Gallium trace 0.0058 0.0048 0.0078 Manganese 0.11 0.041 0.017 0.051 Chromium 0.012 0.017 0.022 0.016 Nickel 0.0045 0.013 0.012 0.012 Vanadium nil 0.020 0.015 0.020 Copper 0.00095 0.011 0.0069 0.0087 Sodium 1.4 2.1 3.4 3.0 Zirconium 0.0029 0.010 0.0058 0.012 Cobalt trace 0.0028 0.0027 0.0041 Potassium 0.71 1.2 4.2 2.3 Strontium 0.070 0.046 0.030 0.049 Tin nil nil 0.0095 trace Phosphorus nil 256 Element AHF 8418 AHF 8419 AHF 8421 AHF 8422 Silicon 17.0 18.0 18.0 18.0 Aluminum 9.6 7.4 9.4 10.0 Iron 4.0 15.0 3.0 2.6 Calcium 6.8 6.1 9.7 3.0 Magnesium 3.4 2.4 2.0 2.8 Titanium 0.78 0.49 0.72 0.75 Barium 0.10 nil 0.11 trace Boron 0.0034 0.018 0.0077 nil Lead nil trace nil 0.026 Gallium 0.0057 0.0033 0.0030 0.0061 Manganese 0.021 0.032 0.022 0.032 Chromium 0.018 0.088 0.026 0.0084 Nickel 0.010 0.0083 0.014 0.0041 Vanadium 0.019 0.040 o.ofr*?, 0.018 0.020 Copper 0.0060 0.0096 0.011 Sodium 3.1 1.3 1.7 4.1 Zirconium 0.011 0.0084 0.0063 0.026 Cobalt 0.0027 trace 0.0019 0.0028 Potassium 4.3 1.3 1.4 8.5 Strontium 0.043 0.018 0.042 0.039 Tin nil nil nil 0.0059 Phosphorus nil nil 0.96 nil 1 257 Element AHF 8424 AHF 8424 AHF 8425 AHF 8426 Silicon 17.0 21.0 21.0 19.0 Aluminum 8.9 11.0 8.1 8.6 Iron 3.8 3.9 4.4 3.4 Calcium 9.3 3.0 6.8 7.6 Magnesium 3.3 4.0 3.5 3.8 Titanium 0.97 0.81 0.69 0.89 Barium 0.088 0.057 0.078 trace Boron 0.0030 0.0021 0.G031 0.0022 Lead nil nil nil nil Gallium 0.0055 0.0074 0.0049 0.0049 Manganese 0.024 0.052 0.033 0.025 Chromium 0.018 0.013 0.020 0.035 Nickel 0.0097 0.0074 0.012 0.015 Vanadium 0.025 0.024 0.019 0.021 Copper 0.0036 0.0050 0.0048 0.0029 Sodium 2.0 2.8 2.1 2.3 Zirconium 0.0084 0.016 0.0074 0.0088 Cobalt 0.0033 0.0041 0.0028 0.0032 Potassium 3.3 3.9 1.6 1.4 Strontium 0.052 0.037 0.044 0.037 Tin 258 Element AHF 8686 AHF 8687 AHF 8688 AHF 8689 Silicon 18.0 20.0 21.0 16.0 Aluminum 10.0 11.0 9.1 7.9 Iron 3.6 4.0 4.3 2.1 Calcium 5.2 7.2 7.7 14.0 Magnesium 3.5 2.4 2.8 2.1 Titanium 0.88 0.75 0.68 0.87 Barium trace trace 0.079 trace Boron 0.0026 0.0052 0.0038 0.0026 Lead nil nil nil nil Gallium 0.0063 0.0061 0.0047 trace Manganese 0.025 0.044 0.054 0.022 Chromium 0.019 0.013 0.021 0.014 Nickel 0.0052 0.012 0.016 0.0032 Vanadium 0.025 0.015 0.017 0.012 Copper 0.0035 0.0088 0.0073 0.0022 Sodium 2.9 1.9 1.7 1.6 Zirconium 0.020 0.0085 0.0079 0.0058 Cobalt 0.0026 0.0024 0.0033 0.0014 Potassium 4.0 1.2 1.2 0.86 Strontium 0.044 0.032 0.040 0.046 Tin nil nil nil nil 259 Element AHF 8691 AHF 8692 NOTS-G-1 NOTS-G-2 Silicon 19.0 21.0 23.0 25.0 Aluminum 7.4 9.0 7.6 6.8 Iron 2.3 3.3 2.3 3.7 Calcium 12.0 7.6 7.6 4.7 Magnesium 2.5 2.9 3.1 3.4 Titanium 1.0 0.94 0.48 0.55 Barium nil 0.11 0.049 0.067 Boron trace 0.0031 0.0024 0.0046 Lead trace nil nil nil Gallium 0.0044 0.0035 0.0034 0.0064 Manganese 0.031 0.037 0.089 0.046 Chromium 0.010 0.012 0.018 0.015 Nickel 0.0034 0.0086 0.0071 0.013 Vanadium 0.014 0.015 0.016 0.017 Copper 0.0016 0.0048 0.0030 0.0076 Sodium 2.3 1.7 1.9 2.4 Zirconium 0.014 0.0086 0.0081 0.0087 Cobalt 0.0020 0.0019 trace 0.0038 Potassium 1.2 1.7 1.4 2.1 Strontium 0.041 0.023 0.019 f 0.044 Tin trace 0.0065 260 Element NOTS-G-3 N0TS-4B NOTS-5 NOTS-6 Silicon 21.0 19.0 18.0 17.0 Aluminum 9.7 10.0 7.2 9.2 Iron 4.7 3.5 3.6 3.6 Calcium 5.9 7.2 9.3 9.1 Magnesium 2.5 2.5 3.7 3.4 Titanium 0.55 0.67 1.5 0.85 Barium 0.14 trace 0.082 0.085 Boron 0.0056 0.0018 0.0036 0.0039 Lead nil nil nil nil Gallium 0.0068 0.0059 0.0064 0.0054 Manganese 0.060 0.026 0.023 0.033 Chromium 0.013 0.023 0.017 0.015 Nickel 0.018 0.0089 0.0091 0.011 Vanadium 0.015 0.015 0.020 0.020 Copper 0.0070 0.0033 0.0052 0.0034 Sodium 2.2 2.6 2.3 2.5 Zirconium 0.010 0.015 0.0074 0.0058 Cobalt 0.0034 0.0028 0.0028 0.0029 Potassium 2.0 1.8 2.0 1.9 Strontium 0.043 0.029 0.022 0.056 261 Element NOTS-7 NOTS-8 N0TS-9 N0TS-10 Silicon 22.0 19.0 19.0 20.0 Aluminum 4.6 8.1 9.3 8.6 Iron 1.0 3.0 3.5 3.7 Calcium 13.0 11.0 9.3 6.5 Magnesium 1.4 3.1 2.6 3.4 Titanium 0.25 0.80 1.2 0.83 Barium nil 0.088 nil 0.43 Boron 0.0053 0.0027 0.0019 0.0035 Lead 0.012 nil nil nil Gallium nil 0.0045 0.0037 0.0051 Manganese 0.030 0.027 0.028 0.022 Chromium 0.038 0.013 0.015 0.032 Nickel 0.012 0.010 0.0046 0.011 Vanadium 0.043 0.015 0.014 0.055 Copper 0.0072 0.0049 0.0035 0.0049 Sodium 1.6 1.8 1.5 2.6 Zirconium 0.0028 0.0078 0.011 0.014 Cobalt trace 0.0025 0.0021 0.0028 Potassium 0.83 1.4 1.6 2.4 Strontium 0.035 0.044 0.032 0.048 262 Element NOTS-11 NOTS-15 NOTS-16 NOTS-17 Silicon 22.0 23.0 21.0 20.0 Aluminum 9.7 9.4 8.3 9.7 Iron 4.5 8.8 0 0 • r- 4.0 Calcium 4.3 3.4 6.5 7.1 Magnesium 2.5 2.1 2.9 3.3 Titanium 0.76 0.67 0.75 0.77 Barium 0.10 nil nil 0.084 Boron 0.0072 0.015 0.027 0.0032 Lead nil nil nil nil Gallium 0.0059 0.0063 0.0080 0.0047 Manganese 0.016 0.037 0.034 0.036 Chromium 0.015 0.065 0.058 0.018 Nickel 0.012 0.0068 0.0080 0.010 Vanadium 0.021 0.032 0.035 0.021 Copper 0.012 0.0046 0.0075 0.0084 Sodium 1.6 1.3 1.5 1.5 Zirconium 0.0082 0.0092 0.011 0.012 Cobalt 0.0030 trace trace 0.0029 Potassium 1.5 1.5 2.2 1.8 Strontium 0.035 0.016 0.015 0.039 263 Element NOTS-18 N0TS-18A NOTS-19 NCEL-1 Silicon 17.0 17.0 18.0 18.0 Aluminum 12.0 11.0 10.0 8.8 Iron 5.1 5.4 4.4 3.5 Calcium 6.9 6.3 6.1 9.6 Magnesium 3.0 4.1 3.2 3.7 Titanium 0.90 0.94 0.80 0.77 Barium 0.069 0.077 0.094 0.093 Boron 0.0026 0.0023 0.0020 0.0032 Lead nil nil trace Gallium 0.0072 0.0082 0.0062 0.0059 Manganese 0.029 0.031 0.029 0.021 Chromium 0.020 0.017 0.016 0.018 Nickel 0.011 0.0097 0.0094 0.010 Vanadium 0.030 0.026 0.016 0.020 Copper 0.0076 0.0078 0.0061 0.0037 Sodium 1.9 2.2 2.0 Zirconium 0.012 0.017 0.010 0.0085 Cobalt 0.0041 0.0041 . 0.0023 0.0026 Potassium 2.5 2.8 3.9 3.1 Strontium 0.032 0.045 0.031 0.028 264 Element NCEL-2 NCEL-3 NCEL-4 NCEL-5 Silicon 16.0 16.0 15.0 17.0 Aluminum 7.8 8.5 7.5 8.6 Iron 3.8 3.9 3.0 3.4 Calcium 11.0 8.8 12.0 11.0 Magnesium 4.1 3.9 3.7 2.9 Titanium 0.63 0.64 0.70 0.62 Barium 0.075 0.084 0.12 0.090 Boron 0.0027 0.0055 0.0032 0.0039 Gallium 0.0063 0.0076 0.0075 0.0055 Manganese 0.027 0.029 0.016 0.040 Chromium 0.017 0.018 0.018 0.017 Nickel 0.0098 0.018 0.010 0.012 Vanadium 0.017 0.024 0.021 0.015 Copper 0.0061 0.0084 0.0056 0.0046 Sodium 2.9 3.6 3.4 2.6 Zirconium 0.0083 0.0072 0.0096 0.0083 Cobalt 0.0028 0.0045 0.0022 0.0025 Potassium 3.6 4.9 4.1 3.6 Strontium 0.038 0.032 0.032 0.034 Tin trace 0.0091 trace nil APPENDIX D Spectrochemical Ratios of Some Santa Catalina Basin Area Samples (0-3 cm Interval) Sample Number Si/Al Al/Fe Ca/Mg Fe/Ti Ba/Ti Ca/Sr Ni/V AHF 8314 2.39 2.59 1.50 4.85 0.137 143 0.800 AHF 8315 2.56 1.87 1.50 7.58 0.141 150 0.833 AHF 8316 2.11 2.72 2.00 4.18 0.139 135 0.824 AHF 8317 1.73 2.50 1.92 5.50 0.108 140 0.650 AHF 8318 2.68 3.50 6.93 3.56 — 258 — AHF 8319 2.56 2.39 2.22 4.56 0.127 146 0.650 AHF 8320 1.73 2.56 3.00 3.96 0.111 320 0.800 AHF 8321 2.39 1.83 1.60 7.50 0.116 140 0.595 AHF 8418 1.77 2.40 2.00 5.13 0.128 158 0.527 AHF 8419 2.43 0.494 2.54 30.6 — 340 0.207 AHF 8421 1.915 3.13 4.85 4.17 0.158 231 0.778 AHF 8422 1.80 3.85 1.07 3.47 — 77 0.205 AHF 8424A 1.91 2.34 2.82 3.92 0.0907 179 0.388 AHF 8424B 1.91 2.82 0.750 4.82 0.0703 81 0.308 AHF 8425 2.59 1.84 1.94 6.38 0.113 155 0.632 AHF 8425Z 2.14 2.22 2.82 4.45 0.0955 221 0.578 AHF 8426 2.21 2.53 2.00 3.82 — 205 0.714 imple Number Si/Al Al/Fe Ca/Mg Fe/Ti Ba/Ti Ca/Sr Ni/V AHF 8686T 1.80 2.78 1.49 4.09 — 118 0.208 AHF 8687 (Top) 1.82 2.75 3.00 5.27 — 225 0.800 AHF 8688 2.31 2.12 2.75 6.33 0.116 193 0.942 AHF 8689 2.02 3.76 6.68 2.42 — 304 0.267 AHF 8691C 2.57 3.22 4.80 2.30 — 293 0.243 AHF 8692 2.33 2.73 2.62 3.51 0.117 330 0.573 AHF 2375 2.53 4.18 2.70 3.10 0.211 195 no value AHF 1633 2.87 4.10 3.30 3.04 0.205 185 no value AHF 2187 3.16 3.30 2.75 3.44 0.175 220 no value AHF 2188 2.73 4.00 2.08 3.55 0.232 224 no value NOTS-G-1 3.03 3.30 2.45 4.69 0.102 400 0.444 NOTS-G-2 3.68 1.84 1.38 6.74 0.122 107 0.765 NOTS-G-3 2.165 2.06 2.36 8.55 0.254 137 1.20 N0TS-4B 1.90 2.86 2.88 5.225 — 248 0.594 NOTS-5 2.50 2.00 2.51 2.40 0.0540 423 0.455 NOTS-6 1.85 2.56 2.68 4.23 0.100 168 0.550 ( O - j Sample Number Si/Al Al/Fe Ca/Mg Fe/Ti Ba/Ti Ca/Sr Ni/V NOTS-7 4.78 4.60 9.28 4.00 — 372 0.279 NOTS-8 2.35 2.70 3.55 3.75 0.111 250 0.667 NOTS-9 2.04 2.37 3.58 2.92 — 290 0.328 NOTS-IO 2.32 2.32 1.91 4.46 0.518 135 0.200 NOTS-11 2.27 2.16 1.72 5.92 0.132 123 0.572 HOTS-15 2.45 1.07 1.62 13.1 — 212 0.213 NOTS-16 2.53 1.065 2.24 10.4 — 433 0.285 NOTS-17 2.06 2.42 2.15 5.20 0.109 182 0.477 NOTS-18 1.42 2.36 2.30 5.60 0.0767 216 0.367 N0TS-18A 1.545 2.04 1.54 5.74 0.0820 140 0.373 HOTS-19 1.80 2.27 1.91 5.50 0.118 197 0.588 Sta. Cat. #1 2.36 2.47 1.24 5.07 0.124 124 0.372 w o* 00 n o too too SANTA BARBARA tSLi Q t PLATE BATHYMETRIC CHART OF B A SIN AREA, C O NTO UR IM TE R M M . T. . . .T. ■ ■ .T ( M U III SOUNDINGS BASED UPON U.S.Cafl.3. SOUNDINGS FROM THE ALLAN HANCOCI PLATE 1 ; CHART O F THE S A N T A CATALIN A B A S IN AREA, CALIFORNIA C O N T O U R M T B M L 1 0 0 MC T E M 0 IM9 AMO M S 1111111111 I i i i i I i i i i I K A U IIMMftl HINDINGS BASED UPON U.&CB&& ORIGINAL SURVEYS AND ECHO >IN G S FROM THE ALLAN HANCOCK FOUNDATION AND THE U.S. NAVY MN CLEMENTE ISLAND \\\ & too • I / S O •MOO too o t oo too • 1 0' I M L PLATE 2 BATHYM ETRY O F THE E M E SANTA CATALINA B A SIN , J I M ■M ED UPON SURVEY! OF TM I U t NAVAL O F PLATE 2 i OF THE EMERY SEAKNOLL FAUNA BASIN, CALIFORNIA. IVCVt or THE a t N A V A L O N Q N A N C C T E A T tTAT IO N , M tA O C N A , saL PLATE 2 BATHYMETRY O F THE EMERY SEAKNOLI SANTA CATALINA BASIN. CALIFORNIA. SOUNDINQS BASED UPON SURVEYS OP THE US. NAVAL ORDNANCE TEST STATION, AND THE ALLAN HANCOCK FOUNDATION CONTOUR INTERVAL 10 METERS SCALE 1:20,000 PLATE 2 ' O F THE EM ERY SEAKNOLL ‘ALINA BASIN, CALIFORNIA. VEVS OF THE U& NAVAL ORDNANCE TEST STATION,PASADENA, THE ALLAN HANCOCK FOUNDATION 20NT0UR INTERVAL 10 METERS SCALE 1.20,000 DETAIL OF THE TOP OF OSBORN BANK 8 DETAIL OF THE TOP OF OSBORN BANK 38 *2# CONTOUR RITCRWU. S NCTIRI PLATE 3 BATHYMETRY OF OSBOR BATHYMETRIC DATA FROM U.&C ALLAN HANCOCK I AND MARINE ADVISORS, INC CONTRACT DATA O B U.S NAVAL ORDNANCE TEST STATION, PASADEN OEPTHS IN METERS BELOW MLLt HORIZONTAL DISTANCES IN METER CONTOUR INTERVAL AS INDICATED SEPTEMBER IM S PLATE 3 *Y OF OSBORN BANK :OM U.SC ALLAN HANCOCK FOUNDATION CRUISES i, INC. CONTRACT DATA OBTAINED FROM THE ICE TEST STATION, PASADENA CALIFORNIA. PTHS IN METERS BELOW MLLW 1IZONTAL DISTANCES IN METERS N TO U R INTERVAL A S INDICATED SEPTEMBER IMS M * MM ■ ■ i __I __I __I — I __l__J K4U

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Asset Metadata

Creator Gaal, Robert Arthur Paul (author)

Core Title Marine Geology Of The Santa Catalina Basin Area, California

Degree Doctor of Philosophy

Degree Program Geology

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

Tag Geology,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Gorsline, Donn S. (committee chair), Reith, John W. (committee member), Stone, Richard O. (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c18-204765

Unique identifier UC11360672

Identifier 6608787.pdf (filename),usctheses-c18-204765 (legacy record id)

Legacy Identifier 6608787.pdf

Dmrecord 204765

Document Type Dissertation

Rights Gaal, Robert Arthur Paul

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

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...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA