University of Southern California Dissertations and Theses

Seismic stratigraphic study of the California Continental Borderland basins: Structure, stratigraphy, and sedimentation

(USC Thesis Other)

Seismic stratigraphic study of the California Continental Borderland basins: Structure, stratigraphy, and sedimentation

PDF

Download

Open document

Flip pages

Download a page range

Download transcript

Copy asset link

Request this asset

Transcript (if available)

Content SEISMIC STRATIGRAPHIC STUDY OF THE CALIFORNIA CONTINENTAL
BORDERLAND BASINS:
STRUCTURE, STRATIGRAPHY, AND SEDIMENTATION
by
Louis; Sui-Yui Teng
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
(Geological Sciences)
April 1S85
UMI Number: DP28574
All rights reserved
INFORMATION TO ALL USERS
The quality of this reproduction is dependent upon the quality of the copy submitted.
In the unlikely event that the author did not send a complete manuscript
and there are missing pages, these will be noted. Also, if material had to be removed,
a note will indicate the deletion.
Dissertation Publishing
UMI DP28574
Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author.
Microform Edition © ProQuest LLC.
All rights reserved. This work is protected against
unauthorized copying under Title 17, United States Code
uest'
ProQuest LLC.
789 East Eisenhower Parkway
P.O. Box 1346
Ann Arbor, Ml 48106-1346
UNIVERSITY OF SOUTHERN CAUFORNIA
TH E G RADUATE SC H O O L
UN IVER SITY PARK
LOS ANGELES, C A U F O R N IA 90089
This dissertation, written by
Louis Suh-Yui Teng
under the direction of .. Dissertation
Committee, and approved by all its members,
has been presented to and accepted by The
Graduate School, in partial fulfillm ent of re
quirements fo r the degree of
D O C T O R O F P H IL O S O P H Y
Dean
D a te..
DISSERTATION COMMITTEE
Chairperson
ACKNOWLEDGEMENT
The writer is greatly indebted to his committee chairman
and dissertation advisor Dr. Donn S. Gorsline for his
guidance and encouragement for all these years. His
perennial enthusiasm and profound knowledge enlighted the
writer’s interest in marine geology and led the writer to
work through his research. .Thanks are also due to other
members of the committee, Drs. Thomas L. Henyey, David J.
Bottjer, Douglas W. Burbank, and Jiin-Jen Lee for their
guidance and valuable advice on the writer’s study.
For this study, a great amount of seismic reflection
data were provided by Union Oil Company of California, for
which the writer wishes to express his great gratitude.
Special thanks are due to Geophysicists Michael T. Reblin
and David P. Eichen and Geologist Thomas w. Redin for their
ardent help and beneficial discussions.
The writer would also like to thank Drs. Brian D.
Edwards, H. Gary Greene and Jack G. Vedder of the U.S.
Geological Survey for providing seismic reflection data and
giving instructive discussions. Thanks are extended to Mr.
Thomas Chase for providing seismic data and trackiine maps.
During the writer’s research, many friends and colleages
in the Department of Geological Sciences have offered
helpful advices and assistance. The writer wishes to give
special thanks to Charles E. Savrda, Suzanne Reynolds, and
Alex P. Carlos for their helpful discussions and advice in
dissertation preparation.
ABSTRACT
The California Continental Borderland is a geologically
complicated territory characterized by intricate
geomorphologic as well as structural features. The
intertwining ridges and basins make the Borderland an ideal
natural laboratory for marginal basin sedimentation. Based
on seismic reflection data, the structure, stratigraphy,
and sedimentation of the Borderland basins have been
invest igated.
By and large, the Borderland and associated coastal area
are composed of two comparable belts in terms of the
pre-Neogene basement geology. Each belt consists of an
eastern zone characterized by a thick Mesozoic to Paleogene
sedimentary sequence and a western zone characterized by
the coeval melange deposits. The coupling of the two zones
resembles the Great Valley Sequence - Franciscan Complex
couple that characterised the California continental margin
during the early Tertiary. The outer Borderland belt is
believed to be a sliver of continental margin that has been
transposed to the present position by Neogene tectonism.
In terms of Neogene structural features, the Borderland
can be divided into two structural terrains. The northern
terrain, which comprises Santa Barbara Basin and the
northern Channel Islands, is characterized by E-W trending
compressional features with sinistral component that are
associated with the structural grain of the Transverse
Ranges. The southern terrain, which includes the rest of
the Borderland, is characterized by NNW-SSE to NW-SE
trending dextral as well as compressional features that
comply with the structural grain of the Peninsular Ranges.
Stratigraphically, many of the Borderland basins share
comparable characteristics in spite of the differences in
sediment thickness. Patton and Tanner Basins are floored
with Franciscan-tvpe basement draped by Miocene sequences
and filled with Miocene to Recent deposits. Santa Cruz,
San Nicolas, and probably Santa 3arbara Basins are floored
with a thick Mesozoic to Paleogene sequence draped by
Miocene layers and filled with Pliocene to Recent
sediments. Santa Monica and San Pedro Basins are floored
with Franciscan-type basement draped by Miocene sequences
and filled with thick Pliocene to Recent deposits.
Catalina Basin and San Diego Trough are also floored with
Franciscan-type deposits, but they are filled with Miocene
to Recent sediments. As inferred from the outcrop and core
v
sample studies, the Mesozoic to Paleogene sequences are
composed of shallow to deep water clastic deposits. The
coeval Franciscan-type basement is made up of melange
deposits. The Miocene sequences are mainly diatomaceous
shales, volcaniclastics, and mass-flow deposits. The
Pliocene to Recent sequences are mainly mass-flow deposits
and hemipeiagics.
The present Borderland basins did not begin to take
shape until late Miocene. Genuine basin-fill deposits
whose distribution is confined to the basins are the
Pliocene to Recent sequences. For the offshore basins,
such as Patton, Tanner, Santa Cruz, and San Nicolas,
fine-grained mass-flow deposits and hemipeiagics derived
from the neighboring insular sources dominate the
basin-fill sequences. Catalina Basin is a transitional
zone between the offshore and nearshore basins, in which
fine-grained turbiaitic deposits and hemipeiagics derived
from both insular sources and the continent have been
deposited. For the nearshore basins, including Santa
Barbara, Santa Monica, San Pedro basins, and San Diego
Trough, a huge amount of continent-derived sediment has
been dumped into the depressions often as prominent
deep-sea fans spreading over the entire basins.
Coarse-grained mass-flow deposits may be the dominant
v i
facies in the nearshore basin-fill sequences instead of the
fine-grained turbidites and hemipeiagics.
The Cenozoic geologic evolution of the Continental
Borderland has been dominated by the interactions between
the East Pacific Rise and the North American Plate. During
the Mesozoic to early Paleogene, the southern California
coastal area was a part of the active margin characterized
by the couplet of a coherent forearc sedimentary sequence
and a coeval trench melange deposit. At about 29 Ma, the
East Pacific Rise collided with the North American
Continent and began to transform subduction activities to
wrench tectonics. The transcurrent movements were
concentrated along the coastline in early Miocene and
transposed a sliver of continental margin situated south o
San Diego northward to offshore California to form the
present outer Borderland. Associated with the wrench
tectonism, magmatic activities and diastrophic movements
spread widely over the Borderland and caused drastic
subsidence and uplift in this area. At about 5 Ma, the
major transcurrent movements jumped inland to the present
San Andreas Fault. The wrench tectonics dwindled in the
Borderland and in many places have been overwhelmed by the
compressional activities associated with the uplift of the
Transverse Ranges. The present configuration of the
Borderland has been forged mainly in this period.
vi i
i-i,
The origin of Borderland basins cannot be attributed to
wrench tectonics alone as used to be thought. Thermal
subsidence as a result of cessation of magmatic activities
in the Miocene provided the basis for basin formation.
Compression shaped the broad highs-and-lows configuration
of the present Borderland and outlined the framework for
the basins. Wrench tectonism determined the loci of the
E
basins by means oc pull-apart, transverse blocking, and
sagging.
Based on the stratigraphic characteristics of the
Borderland basins, three major paleoceanographic events can
be inferred. The widespread occurrence of Miocene
biogenic pelagic sequences indicates that the Miocene was a
period of high sea stand and high bioproductivity in
southern California. The unconformity often present within
the Miocene sequences is believed to represent the sea
level fall at about 14 Ma. The abrupt change of Miocene
biogenic pelagic sedimentation to Pliocene mass-flow
deposition is attributed to the paleoceanographic changes
associated with the sea level fall at about the
Mio-Piiocene boundary (about 4.5 Ma, and possibly 6.2 Ma).
The distinct boundary between the old and young basin-fill
sequences is thought to reflect a period of slow
sedimentation in consequence of the sea level rise at about
2.8 Ma. These paleoceanographic changes are consistent
with the global eustatic fluctuations and with other
paleoceanographic studies on the southern California and
other parts of the world.
ix
CONTENTS
ACKNOWLEDGEMENT............................................... i i
ABSTRACT....................................................... iv
Chapter page
I. INTRODUCTION ............................................. 1
Previous study ........................................ 4
Geomorphologicai study .......... * 4
Petrological study .............................. 5
Sedimentological study ......................... 5
Seismic stratigraphic studies in the
Borderland ..................................... 7
Purpose of study.................................... . 9
II. PRINCIPLES OF SEISMIC STRATIGRAPHY ............... 11
Fundamentals of Seismic Profiles ............... 13
Deep-penetration profiles .................... 16
Intermediate-penetration profiles .......... 16
Shallow-penetration profiles ............ , 16
Interpretation.............. 31
Structural analysis ........................... 32
Sequence analysis .............................. 33
Facies analysis ................................ 34
Geohistory analysis ........................... 35
III. STRUCTURAL FRAMEWORK OF THE BORDERLAND .......... 37
Paleogene Geologic Terrains .................... 38
Inner Borderland.................................41
Outer Borderland .......................45
Neogene structural features................. 49
Northern t e r rain...................... 52
Southern terrain .............................. 57
IV. STRATIGRAPHIES OF THE BORDERLAND BASINS .......... 63
Patton and Tanner Basins ......................... 64
Santa Cruz and San Nicolas B a s i n s ................69
x
Santa Barbara B a s i n .................................74
Santa Monica, San Pedro, and Catalina
Basins, and San Diego Trough................75
V. SEDIMENTATION OF THE BORDERLAND BASINS .......... 82
Depositional systems and seismic facies . . . 83
Shelf f a c i e s ......................................83
Slope f a c i e s ......................................88
Basinal facies ................................ 88
Submarine fan systems and seismic facies . . . 88
Fan settings......................................89
Fan f a c i e s .........................................93
Facies patterns of basin-fill sequences . . . 94
Patton B a s i n ................■.....................94
Tanner Basin ................................... 99
Santa Cruz B a s i n .................................99
San Nicolas Basin . . . . ......................108
Catalina Basin ................................113
Santa Barbara Basin...............................118
Santa Monica B a s i n ...............................123
San Pedro Basin.................................. 128
San Diego T r o u g h ................................133
Sediment accumulation rates .................... 138
VI. SYNTHESIS................................................. 143
Tectonic Evolution of the California
Continental Borderland .................... 143
Formation of Borderland Basins ................. 155
Thermal subsidence ........................... 156
Compression....................................... 157
Wrench tectonism .............................. 157
Paleoceanographic Events ......................... 170
Miocene event ................................... 171
Mio-Pliocene event ........................... 172
Pliocene event ................................ 173
VII. CONCLUSIONS...............................................178
REFERENCES...................................................... 186
x i
LIST OF TABLES
Table page
1. Total accumulation rates of the Borderland
Basins.....................................................139
2. Unit accumulation rates of the Borderland
Basins.....................................................140
x i i
LIST OF FIGURES
F i gure page
1. Bathymetric map of the California Continental
Borderland. (From Moore, 1969) . . . 2
2. Deep-penetration profiles, west Santa Barbara
Basin.....................................................17
3. Trackline map of the deep-penetration profiles
from oil industry source........... 19
4. Intermediate-penetration (sparker) profiles,
east Santa Barbara Basin..........................21
5. Trackline map of the intermediate-penetration
profiles from U. S. Geological Survey files. . 23
6. Shallow-penetration (air-gun) profiles, Central
Catalina Basin.......................................25
7. High-resolution (3.5 KHz) profiles, Central
Catalina Basin.......................................27
8. Trackline map for shallow-penetration profiles
from USC marine geology laboratory. ...... 29
9. Geologic terrains of the California Continental
Borderland and associated coastal region. . . . 39
10. Schematic cross-section of California
Continental Borderland.............................42
11. Line drawing of the seismic profiles across the
outer Borderland....................................46
12. Examples of the hierarchy of structural
features, Santa Cruz Basin........................50
13. Structural framework of the Continental
Borderland, southern California................. 53
xi i i
14. Neogene structures of the Continental
Borderland, southern California......................55
15. Stratigraphic schemes of the Borderland basins. . 65
16. Stratigraphic column for Patton and Tanner
Basins. Thicknesses are relative in the
diagram....................................................67
17. Stratigraphic column for Santa Cruz, San
Nicolas, and possibly Santa Barbara Basins.
Thicknesses are relative in the diagram. . . . 70
18. Stratigraphi£ column for Santa Monica and San
Pedro Basans. Thicknesses are relative in
the diagram...............................................76
19. Stratigraphic column for Catalina Basin and San
Diego Trough. Thicknesses are relative in
the diagram...............................................78
20. Diagrammatic depositional settings and facies
of the continental margin, (after Brown and
Fisher, 1977)......................................... 84
20. Facies analysis on Seismic Profiles,Santa
Monica Basin..............................................86
22. Depositional settings of submarine fan.
a. American model (after Normark, 1978),
b. European model (after Rupke, 1978)........... 90
23. Depositional systems of the Lower to Middle
Pliocene sequences (PI), Patton Basin.............. 95
24. Depositional svstems'of the Upper Pliocene to
Recent sequences (P2), Patton Basin.................97
25. Depositional systems of the Lower to Middle
Pliocene sequences (PI), Tanner Basin.............100
26. Depositional systems of the Upper Pliocene to
Recent sequences (P2), Tanner Basin................102
27. Depositional systems of the Lower to Middle
Pliocene sequences (PI), Santa Cruz Basin. . . 104
28. Depositional systems of the Upper Pliocene to
Recent sequences (P2), Santa Cruz Basin. . . . 106
xiv
109
111
114
116
119
121
124
126
129
131
134
136
146
148
151
xv
Depositional systems of the Lower to Middle
Pliocene sequences (PI), San Nicolas Basin, .
Depositional systems of the Upper Pliocene to
Recent sequences (P2), San Nicolas Basin. . .
Depositional systems of the Lower to Middle
Pliocene sequences (PI), Catalina Basin. . ,
Depositional systems of the Upper Pliocene to
Recent sequences (P2), Catalina Basin. . . .
Depositional systems of the Lower to Middle
Pliocene sequences (PI), Santa Barbara
Basin.................................................
Depositional systems of the Upper Pliocene to
Recent sequences (P2), Santa Barbara Basin. .
Depositional systems of the Lower to Middle
Pliocene sequences (PI), Santa Monica Basin,
Depositional systems of the Upper Pliocene to
Recent sequences (P2), Santa Monica Basin. . .
Isopach map of the Lower to Middle Pliocene
sequences (PI), San Pedro Basin................
Depositional systems of the Upper Pliocene to
Recent sequences (P2), San Pedro Basin, . . ,
Depositional systems of the Lower to Middle
Pliocene sequences (PI), San Diego Trough.
Depositional systems of the Upper Pliocene to
Recent sequences (P2), San Diego Trough. . .
Paleogeographic reconstruction of the southern
California continental margin at around 30
Ma....................................................
Paleogeographic reconstruction of the southern
California continental margin at around 15
Ma....................................................
Schematic paleogeography of the California
Continental Borderland at around 15 Ma. . . .
44. Paleogeographic reconstruction of the southern
California continental margin at around 2
Ma............................ I ......................... 153
45. Pull-apart mechanism and associated structural
pattern in the Patton-Tanner Low. a.
Schematic drawing, b. Structural features.
The dotted bands are the Santa Rosa-Cortes
and Patton Fault Zones respectively................15S
46. Transverse blocking and associated structural
features in the Santa Monica Belt. a. Late
Miocene, b. Present.................................. 161
47. Subsidence of Santa Monica Basin as related to
structural features. a. Lower to middle
Pliocene, b. Upper Pliocene to Recent...........164
48. Schematic picture of sagging, along the
transcurrent fault.....................................166
4S. Subsidence of San Pedro Basin as related to
structural features. a. Lower ro middle
Pliocene, b. Upper Pliocene to Recent........... 168
50. Neogene paleoceanographic fluctuations and
stratigraphic evolution in Tanner and other
Borderland Basins......................................175
xvi
Chapter I
INTRODUCTION
The California Continental Borderland, as first proposed
by Shepard and Emery (1941), comprises the offshore area
bounded by the coastline and the 3000-m isobath on Patton
Escarpment between Point Argueilo, California and Isla
Cearos, Baja California. The northern half of the
Borderland within the United States territory is the area
involved in this study (Figure 1). Topographically, this
area is characterized by a series of basins and ridges
which make up a highly complicated continental margin. The
depths of the basins decrease from the nearshore inner
basins ( Santa Monica and San Pedro 3asins, max. depth 900
m) toward the offshore outer basins ( San Nicolas and
Tanner Basins, max. depth 1800 m) and from the northern
basins ( Santa Barbara Basin, max. depth 600 m) to the
southern basins (Velero Basin, max. depth 2550 m). Most of
the basins are separated from one another by topograpic
highs (either ridges, banks, or sills) which bar the
sediment of each basin from spilling over to more distal
basins until they have filled to the sill depth.
1
Figure 1 Bathymetric map of the California Continental
Borderland. (From Moore, 1969)
2
EIATHYMETRIC CHART
ERLAND
RNIA
>tV*
: Santa'Barh
CONTINENTAL BORD
SOUTHERN CALIFO
Contours in fathom
m m
: \ %4v ; J
tilViS
\\xi ■ - " v; v - , v. , c" _ ,-—r “« ‘.
Mi , '
Wj>W xl
I li
O ) r > t
\ )\ Vv:\V/^ / ' - ) '
1
m m
<\v - \ \
\ I\ W Vf
\ \\\;'v \ V •
I V ‘f .. \
, , , x , J I J11W1
x ;
11 1 % % %
\ \ ' X ( V x\ (
C O
The topographic complexities are, in fact, the surficial
expression of the intricate geological structures of the
basement. Intense tectonic activities disrupted the whole
Borderland terrain and created the complicated geomorphic
features which affected the sedimentation pattern in the
Borderland basins. The interplay of tectonism and
sedimentation made the California Continental Borderland a
unique geologic terrain as an ideal natural laboratory for
the study of marginal basin sedimentation (Moore, 1969).
1.1 PREVIOUS STUDY
Being an intriguing geological territory, the California
Continental Borderland has been a subject of intense study
during the past 50 years. The basic geologic research can
be grouped into three categories:
1.1.1 Geomorpholoqical study
From the early sounding surveys of the 1920’s to the
recent Gloria project (1984), the topographic features of
the Continental Borderland have been fairly well
recognized, and many studies on the geomorphic provinces
and associated structural implications have been
accomplished (Shepard and Emery, 1941; Emery, 1960; Moore,
1969; Vedder and Toth, 1976).
1•1•2 Petrological study
Petrological studies associated with stratigraphic
analysis have been done on the Borderland in two ways. For
the outcrops on the' islands, basic field mapping and
petrological descriptions have been done and summarized in
a number of publications (Weaver, 1969a; Howell, 1976a)
which also include seme detailed studies. For the
submarine area, dredge hauls and dart core samples have
been raised throughout the area and their lithological
characteristics have been described in a number of reports
(Emery, 1960; Vedder and others, 1974, 1979, 1981a)
Preliminary sea floor geologic maps of the Borderland have
been compiled on the basis of these studies (Emery, 1960;
Vedder and others, 1974).
1.1.3 Sedimentological study
Marine sedimentological research has been one of the
most intense studies in this area. Modern sedimentary
processes along the coast, upon the shelf and slope all the
way down to the deep basins have been investigated,
recorded, and documented (e.g., Ingle, 1966; Drake et al.,
1972; Shepard and Marshall, 1973). Thousands of box cores
and piston cores have been raised and have provided
valuable resources for the study of Quaternary
5
sedimentation in the basins (Gorsline, 1981; Douglas,
1981) .
In addition to the above three categories, many other
studies on the regional tectonics and geologic history of
southern California also involve, more or less, the
Continental Borderland (e.g., Atwater, 1970; Crowell,
1974b; Dickinson and Snyder, 1979)
In spite of the voluminous geologic studies that have
been done in this area, the geology of the Continental
Borderland is far from well understood. The outcrops of
the islands provide bits and pieces of information about
the basement of the Borderland which show hardly any
lateral equivalence and continuity. The dredge and dart
core samples furnish knowledge of the lithology of the
sea-floor bedrocks which, however, offer only indistinct
insights to the regional geology. Studies of box cores and
piston cores have contributed to the understanding of late
Quaternary sedimentation but offer very little help to the
pre-Quarternary geologic history. Owing to the lack of
knowledge about the deep-seated rocks in the submarine
area, the stratigraphy, structural framework and geologic
history of most of the Borderland still remain moot and one
must resort to speculations.
6
1.2 SEISMIC STRATIGRAPHIC STUDIES IN THE BORDERLAND
Seismic techniques have been employed by the petroleum
industry as an exploration method for over 50 years.
Seismic reflection profiles proved to be one of the most
powerful tools for unravelling the subsurface geology. The
reflection profiles provide continuous two-dimensional
pictures of the inaccessible subsurface strata which, when
used in association with drilling data, serve as geologic
cross sections that are not obtainable otherwise.
Especially in sedimentary basin floors where the outcrops
are either limited or inaccessible, seismic reflection
profiles are indispensable for geologic exploration.
Seismic methods have been used in the Borderland area
for about 30 years. In the late 1950's, researchers of the
Scripps Institute of Oceanography launched the pioneer
refraction and reflection studies and thereby developed
some crude crustal models for the 3orderland (Shor and
Raitt, 1958). In the early 1960’s, the U. S. Geological
Survey (USGS) started systematic seismic profiling over the
entire Borderland. The data they collected include
thousands of Km of 3-sec 1 sparker profiles, 2- and 4-sec
air gun profiles and 0.25 sec uniboom profiles. Many of
them have been interpreted and summarized in a number of
1 two way travel time? which is also the time reference of
other profiles in this paper and will not be noted again
7
papers (e.g. Moore, 1969; Junger, 1979). In the
mid-1970's, the University of Southern California (USC)
marine research group joined the seismic profiling team to
collect 1-sec air-gun profiles and 0.25 sec high-resolution
profiles. Many of these data have been analyzed in several
MS and PhD theses (Nardin, 1980; Schwalbach, 1982;
Reynolds, 1984). Both the USGS and USC data are shallow
penetration profiles, they mainly contribute data for the
shallow sea floor geology.
On the other hand, the oil industry also started to
shoot deep- penetration profiles in the late 1950's.
Thousands of Km of 6-9 sec profiles have been collected
over the entire area. However, almost all of them are
propriety data and the studies done by the oil companies on
these data are mostly unpublished. Some other
organizations, such as the U. S. Coast and Geodetic Survey
also did some seismic profiling work in certain areas of
the Borderland.
Up to now, an appreciable amount of seismic reflection
data have been collected from the Borderland area and quite
a few studies have been achieved on the basis of these
data. However, owing to the uneven trackline distribution
and the varied data quality, the academic studies tend to
focus on the shallow surface geology and those by the
8
industry tend to concentrate on the productive areas. The
geologic information extracted from the seismic reflection
data seems to have concentrated in certain areas or on
certain horizons. Very few studies have been published
concerning the regional geologic framework over the entire
Borderland, although good coverage by seismic profiling
lines has been achieved.
x-3 PURPOSE OF STUDY’
Admittedly, the California Continental Borderland is
geologically a very complicated terrain. It is not easy to
get a complete picture of the geologic framework of such an
area on land, let alone in submarine territory. However,
with the help of seismic reflection profiles, it is
possible now to integrate all the available geologic
information and produce an acceptable picture of the
stratigraphy, structure, and geologic history of the
Borderland. The writer has been fortunate to have gained
access to some of the deep-penetration profiles from the
Union Oil Company of California in addition to the
reflection data collected by USGS and USC. Based on these
data, it is the writer’s wish to work out the structural
and stratigraphical evolution of the Borderland and to
probe a little more into the late Neogene sedimentation
history of the basins. Hopefully through this study, a
forward step to the better understanding of the Borderland
geology can be accomplished.
10
Chapter II
PRINCIPLES OF SEISMIC STRATIGRAPHY
Although seismic reflection profiles have been well
regarded as a powerful tool for detecting the subsurface
geology; not everybody utilizes them in the same way.
Petroleum geologists first used seismic profile analysis in
the hope of understanding the subsurface structural
patterns and the location of potential traps for petroleum.
A lot of effort has been funneled into structural analysis
and hydrocarbon detection. Stratigraphic study also
benefits from tying the seismic profiles to exploratory
well data and field geologic information. However; owing
to the complexities of the geology and the varied response
of seismic waves to lithology, stratigraphic interpretation
was not all that definite and is more an art than a
science. In the academic world; marine geoscientists also
utilized seismic reflection profiles to explore the
submarine geology (e.g., Karig and others, 1970), but in a
less sophisticated way than the industrial world.
Seismic stratigraphy was not a well-established
discipline until the mid-1970s when the Exxon research
11
group published their approach to reflection profile
interpretation (Payton, 1977). They proposed a systematic
way of interpreting seismic reflection profiles and
incorporated a refined stratigraphic scheme in the
interpretation. Brown and Fischer (1977, 1980) moved one
step further to tie the seismic stratigraphic
interpretation to the depositional systems. By their
E
efforts, seismic reflection profiles not only serve as a
tool for probing subsurface geology but also provide a new
approach to the analysis of the stratigraphy and
sedimentation history of the depositional basins. Seismic
stratigraphy became a viable and valuable approach to basin
analysis and stratigraphic studies and has been
successfully applied to many areas (e.g., Mitchum, 1978;
Addy and Buffler, 1984). The principles of seismic
stratigraphy have been elucidated in a large exploration
geophysics literature (e.g., Dobrin, 1976; Payton, 1977;
Brown and Fisher, 1980; Sheriff, 1980; Sheriff and Geidart,
1983). It is net the writer’s aim to review all the
essentials of seismic stratigraphy. However, in order to
provide a proper background for understanding the use of
seismic reflection profiles, it is worthwhile to briefly
state the fundamental characteristics of reflection
profiles and the basic steps for interpretation.
12
2.1 FUNDAMENTALS OF SEISMIC PROFILES
Seismic reflection profiles, as they are laid down on
the desk, have already gone through a whole series of
complicated procedures, from field data collection to
laboratory data processing. Each step of the procedure
influences, to various extent, the final printouts of the
reflection profiles. The quality and characteristics of
the reflection profiles depends heavily on these
procedures. Seismic stratiaraphers, when dealing with the
reflection profiles, must take into account the procedures
that the profiles have gone through.
Seismic reflection profiles are not the ultimate product
and have -certain limitations. The most important
limitations are penetration and resolution. Penetration is
mainly determined by the frequency band used in signal
collection and processing. Since the Earth is a low-pass
filter, high frequency signals tend to attenuate quickly at
shallow depth. In order to receive reflected signals from
depth, low frequency signals are often collected. For
example, the frequency band width of air-gun profiles
(Figure. 6) is about 200 to 500 Hz, and their maximum
penetration is about 500 m (0.5 sec). The frequency range
of deep penetration profiles (Figure. 2} is about 5 to 20
Hz. Their maximum penetration may be as much as 6 Km or
even deeper (6 sec).
13
Resolution also depends on the frequency band width of
the seismic signals. The vertical resolution is about 1/8
of the wavelength of the central frequency of the source
signal (Widess, 1973). The higher the frequency, the
smaller the wavelength and the better the vertical
resolution. For example, on air-gun profiles, lithological
units of about 5 m thickness can be recognized, while on
deep-penetrat ion profiles, only those more than 20 m thick
can be distinguished. The lateral resolution is determined
by the radius of the Fresnel zone which is also dependent
on the central frequency of the signal in addition to the
depth (Neidell and Poggiagliomi, 1977). Generally
speaking, the higher the frequency and the shallower the
depth, the better the lateral resolution. For example, on
air-gun profiles, it is possible to recognize a lenticular
bed of 30 m width, while on deep-penetration profiles, only
those wider than 50 m may be recognized at shallow depth,
and the width limit increases as depth increases.
Other factors also affect the penetration and resolution
of the reflection profiles. Enhancement of the source
signal energy, amelioration of field data collection and
the employment of proper data processing procedures all
point to improving both penetration and resolution.
However, all these techniques have their own limitations
and are beyond the expertise of seismic stratigraphers.
14
Seismic stratigraphers, when dealing with the seismic
reflection profiles, generally have to accept the seismic
profiles as they are and try to make the most of them.
Before making any interpretations, seismic stratigraphers
must realize the nature of the reflection profiles, their
applicabilities and limitations. For example, the
deep-penetration profiles provide good insights into the
architecture and large-scale lithological units of the
sedimentary basins, factors which are suitable for basin
analysis; whereas the high resolution profiles offer
detailed pictures of the sea floor lithology and more
recent structural features which are useful for
geotechnical purposes. It is not appropriate to interpret
the Holocene fan-channel systems using deep-penetration
profiles or to infer the regional structural framework on
the basis of high resolution profiles. Bear in mind that
the seismic reflection profiles are artifacts that might
offer valuable clues to subsurface geology if interpreted
properly. Sound interpretations rely on the understanding
of the underlying physical basis and the characteristics of
reflection profiles.
For this study, various kinds of reflection profiles are
available. By and large, they fall into three categories;
15
2.1.1 Deep-penetrat ion prof iles
These were obtained from the oil industry, and have
penetrations of 6 to 9 second two-way travel time. Most of
them have been properly processed so that the data quality
is very good (Figure 2). The tracklines of these profiles
evenly cover the Borderland area (Figure 3) and provide the
basis for the study.
2.1.2 Intermediate-penetrat ion prof iles
These have been provided by the U. S. Geological Survey,
2 to 4 seconds two-way travel time, either sparker or air
gun source, and single channel gathering. These profiles
did not go through deconvolution and migration. Their data
quality is not-as good as the deep-penetration profiles and
may vary appreciably from place to place (Figure 4). The
tracklines of these profiles cover most of the Borderland
(Figure 5) but tend to concentrate in the nearshore areas.
2.1.3 Shallow-penetration profiles
These are available in USC marine geology laboratory,
including 3.5 KHz and air-gun profiles (Figure 6 and 7),
0.25 to 1 second two-way travel time. The tracklines of
these profiles cover a large part of the 3orderland (Figure
8) but the density is fairly low in the outer Borderland.
16
Figure 2: Deep-penetration profiles, west Santa Barbara
Bas in
(see reference map below). The vertical scale
is two-way travel time. The upper profile is
the original stacked section. The lower figure
is the interpreted version. Kp: Cretaceous to
Paleogene sequences; M; Miocene sequences; PI:
Lower to middle Pliocene sequences; P2: Upper
Pliocene to Recent sequences.
17
Slope Facies
Basinal Facies h
| M | 1 1 1
ifllf I
ip^py
mm
SANTA BARBARA BASINj
W H H
co
Figure 3
Trackline map of the deep-penetration profiles
from oil industry source.
IS
TRACKLINE MAP
Deep-penetration Profiles
Industry
50K m
N>
o
Figure 4: Intermediate-penetration (sparker) profiles,
east Santa Barbara Basin.
(see reference map below). The vertic
is two-way travel time. The upper pro
the original stacked section. The low
is the interpreted version. 'M: Miocen
sequences; PI: Lower to middle Pliocen
sequences; P2: Upper Pliocene to Recen
sequences.
1 scale
ile is
r figure
21
Montalvo
Trend
Rincon
Trend
Santa Cruz
Island
M
to
Figure 5 Trackline map of the intermediate-penetra
profiles from U. S. Geological Survey fil
23
f D rf
TRACKLINE MAP
Intermediate-penetration Profiles
USGS
5 0 Km
wf/infth/i'd
K)
it*
Figure 6: Shaliow-penetrat ion (air-gun) profiles, Central
Catalina Basin.
(see reference map below). The vertical scale
is two-way travel time. The upper profile is
the original stacked section. The lower figure
is the interpreted version. M: Miocene
sequences; Pis Lower to middle Pliocene
sequences; P2: Upper Pliocene to Recent
sequences.
25
Catalina Basin
Is r€>
-jEf ;Z n ~ ^ v^ - r f —
L1
: r _ :
i-
I-
z C a ta lin a
Fault
-tarn
Clemente -J|p
25
Figure 7: High-resolution (3.5 KHz) profiles, Central
Catalina Basin.
The vertical scale is two-way travel time. The
upper profile is the original stacked section.
The lower figure is the interpreted version.
The same trackline as Figure 6
27
% Slump Catalina
Fault Scarp
5 Km ( j |
Fine-grained turbidites
and hemipelagics
San
Clemente
Fault Scarp J
\ '
Figure 8 Trackline map for shallow-penetrat ion profiles
from USC marine geology laboratory.
23
TRACKLINE MAP
Shallow-penetration Profiles
USC
50Km
The data quality also varies appreciably.
2.2 INTERPRETATION
Interpretation produces geologic information out of
seismic reflection profiles. Since reflection profiles
display the seismic response of the subsurface strata,
they naturally carry geologic information with them. The
problem is how to interpret them. Different interpreters
have different ways of aesciphering the reflections. Up to
the present, the geologic information that can be obtained
from the reflection profiles includes a whole gamut of
things, from the pore fluids in the reservoir rocks
{Domenico, 1974) to global sea level fluctuations (Vail and
others, 1977b). However, for seismic stratigraphers, the
structural and stratigraphical evolutions of the
depositional basins are the most important issues. In
order to understand the structural and stratigraphical
evolutions, seismic stratigraphers need to investigate the
structural framework, stratigraphy, and sedimentary facies
of the depositional basins. The basic steps of seismic
stratigraphic interpretation pretty much follow these
lines. They are structural, sequence, facies, and
geohistory analyses (Figure 2).
31
2.2.1 Structural analysis
The purpose of structural analysis is to delineate
folds, faults, and other structural features such as
unconformities, swells, and aiapirs on the reflection
profiles. Theoretically, it might sound like an easy
task, simply looking for discontinuities and arching of the
reflection surfaces. But in actuality, it is not as simple
as one might think. Owing to the nuisances of extraneous
seismic signals like diffractions and side echos etc., the
apparent discontinuities and arching in the reflection
profiles are often distorted and fraught with fake
reflections, especially in structurally complicated areas.
It might be very misleading to make straightforward
interpretations on those features. Pitfalls of this kind
have been well exemplified in the literature (Tucker and
Yorston, 1973; Tucker, 1982) and illustrative atlas on
structural interpretation have been published (Bally,
1983a,b,c). It is always instructive to become familiar
with these atlases and the basic principles of ray path
(Sheriff, 1982) before making an interpretation, and to
consult the atlas periodically during the interpretation.
32
2.2.2 Sequence anaiys i s
Sequence analysis is actually a stratigraphic analysis
of reflection profiles. In principle, it is just like
doing stratigraphic analysis on rocks in the field. The
first step is to break the rock strata into subunits.
Owing to the resolution limit of seismic signals, it is not
appropriate to divide the strata into very small units.
The basic unit used in seismic straigraphic interpretation
is a depositional ’’sequence” which is a strat igraphic unit
composed of a relatively conformable succession of
genetically related strata bounded at top and base by
unconformities and their correlative conformities (Mitchum
and others, 1977a). Since the reflection surfaces normally
are parallel with the time plane, a sequence is pretty much
a chronostratigraphic unit rather than a lithostratigraphic
unit. The criteria for defining the sequence boundaries
have been proposed (Mitchum and others, 1977a). However,
like any other stratigraphic divisions, the delineation of
a sequence is arbitrary and subject to prejudices.
Incorporation of other geologic information such as well
log and paleontological data may furnish the sequence with
more geologic significance. A good sequence subdivision is
testable by the consistency of sequence boundaries which
can be checked by the closing of loops. The absolute
33
correctness of sequences can not be ascertained and is not
the goal of the analysis.
2.2.3 Facies analysis
Reflected seismic signals respond to the acoustic
impedance of the rocks, which is, in turn, dependent on the
lithological characteristics. Lithological changes in a
depositional sequence can modify the seismic response of
the reflection surfaces and produce lateral variations in
reflection characteristics. Therefore, based on the
lateral changes in reflection characteristics, the
lithological changes in the sequence can be inferred. A
number of reflection parameters, including configuration,
continuity, amplitude, frequency, and interval velocity
have been proposed as the criteria to define seismic facies
(Mitchum et al., 1977b). However, none of these parameters
are definitive and many of them are heavily affected by
other factors than lithology. In general, configuration
and continuity are more reliable than the other parameters.
Nevertheless, it is advisable to utilize all the parameters
in the interpretation and to blend in the concepts of
depositional systems. Other geologic information such as
regional stratigraphy and core data should also be taken
into account. It is fair to say that facies analysis is
34
very much geology-dependent and should not be done without
proper knowledge about the regional geology and the
depositional systems.
2-2.4 Geohi story analysi s
Based on the knowledge obtained from the previous three
analyses, the final step is to integrate all the geologic
information to depict the geologic history of the study
area. Like any other geohistory interpretation, the more
information, the better the interpretation. The advantage
of- reflection profiles is that they can provide continuous
sections of subsurface strata. With proper assemblage of
the sections, it is easy to get a three-dimensional picture
of the depositional basin, in which the structural
patterns, vertical stratigraphic evolution and lateral
facies changes are manifested. Many geohistory analyses
based on seismic profiles have been accomplished and have
proved to offer valuable clues to the tectonic evolution,
sedimentation and burial history, and sea level
fluctuations of the depositional basins (Stuart and
Caughey, 1977; Vail and others, 1977b; Middleton, 1984).
For this study, the method of interpretation basically
follows these lines. The first step is to depict the
35
structural features and depositional sequences of each
basin. Then integrate all the structural features to
produce a regional structural framework. Then compare and
correlate the sequence stratigraphies of individual basins
to delineate the geologic terrains. Facies analysis has
been done on the post-Miocene sequences for which good data
quality and trackline coverage are available. The last
step is summarizing all the geologic information obtained
from the seismic sections as well as from the literature to
depict the geologic evolution of the Borderland.
36
Chapter III
STRUCTURAL FRAMEWORK OF THE BORDERLAND
As exhibited by the rugged topography, the California
Continental Borderland is a complicated structural terrain.
By and large, the Borderland area can be divided into two
structurally distinctive terrains. Santa Barbara Basin and
the northern Channel Islands constitute one terrain which
is marked by the E-W structural grain associated with the
Transverse Ranges. The rest of the Borderland is
charactrerized by the NW-SE structural grain associated
with the Peninular Ranges. These two terrains are so
distinctive that they have been recognized for a long time
(Moore, 1969). However, the structural patterns that
characterize these terrains are mainly late Neogene
features, because the Borderland has been tectonicaily very
active during late Neogene time. The early Tertiary
structural features have mostly been masked by the later
structural events and become hardly discernible. It is not
the purpose of this study to restore the early Tertiary
structural details. However, based on the knowledge of
regional geology, it is possible to delineate the geologic
terrains of early Tertiary rocks and thereby to infer the
large-scale structural pattern for the early Tertiary
Borderland.
3.1 PALEOGENE GEOLOGIC TERRAINS
On the basis of the basement and early Tertiary geology,
the Borderland and associated coastal area can be divided
into two subparallel belts. Each belt is characterized by
a zone floored with a Mesozoic to Paleogene sedimentary
sequence coupled with a zone floored with Franciscan-type
rocks. (Figure 9). The concept of these zones was first
proposed by Howell (1976b) and then further elaborated by
Crouch (1979, 1981) and Howell and Vedder (1981). The
validity of these zones has been confirmed by this study,
but the boundaries between the zones have been modified to
some extent.
In general, the Borderland area can be split into an
inner belt and an outer belt (Figure 9 and 10). The
boundary between the two belts pretty much follows the line
of Santa Cruz-Catalina and San Clemente Ridges. South of
San Clemente Island, the boundary largely follows the San
Clemente Fault extending into Mexican territory. The
northern stretch of this boundary is cut by the Santa Cruz
Island Fault and obscured by the E-W structural grain.
38
Figure 9: Geologic terrains of the California Continental
Borderland and associated coastal region.
Zones A and C are floored with Mesozoic to
Paleogene sedimentary sequences (Great Valley
Sequence - Type). Zones B and D are floored
with Mesozoic to early Tertiary melange deposits
(Franciscan-type).
39
wmmfm
•X rnMmrn
o
However, since the rocks on Santa Rosa and San Miguel
Islands exhibit more affinity to the outer Borderland belt
{Cole, 1977), it is believed that the boundary extends
northward across the western part of Santa Barbara Basin.
Owing to the lack of geologic information in that area, the
boundary is only tentatively drawn in terms of available
seismic reflection data. The southern extension of the
boundary is out of the study area and can not be
delineated.
3.1.1 Inner Borderland
The inner Borderland belt consists of two zones. Zone A
is floored with granitic basement of the Peninsular Ranges
and covered with Jurassic to Paleogene sedimentary rocks.
The eastern part of Zone A has been uplifted and exposed on
the western slope of the Peninsular Ranges, from the Santa
Ana Mountains down to San Diego and the Mexican coastal
area (Campbell, 1962, 1966; Gastil and others, 1975;
Bottjer and Link, 1984). In Los Angeles Basin, the
pre-Neogene rocks of Zone A are deeply buried by Necgene
sediments. However, based on the available subsurface
information, the presence of these rocks has been verified
(Yerkes and others, 1965). Similar kinds of rock sequences
can be found in the eastern and central parts of the
Transverse Ranges. Sedimentological studies suggest that a
41
Figure 10: Schematic cross-section of California
Continental Borderland.
The location of the (X-Y) is shown in Figure 9
Fe: Franciscan-type basement
Gr: Granitic basement
Om: Ophiolitic basement
Tv: Tertiary volcanics
Kj: Jurassic to Cretaceous sequences
P : Paleogene sequences
M : Miocene sequences
Q : Pliocene to Recent sequences
42
Outer Borderland- - * \ + — Inner Borderland -H I
Zone D h Zone C Zone B ►|<-Zone A -> |
Patton Santa Rosa- San Clemente Newport-Inglewood Margarita
Fault Cortes Fault Fault Fault Mountains
f 4 ^ f
Patton Santa Rosa- San Clemente Catalina
Ridge Coites Ridge Ridge Ridge
part of these rocks resemble those in the Peninsular Ranges
(Link and others, 1984; Bottjer and Link, 1984). Because
these rocks have been severely transposed by Neogene
tectonic movements, their original spatial distribution is
hard to discern. The western limit of Zone A is generally
demarcated by a series of faults. In Los Angeles Basin, it
is roughly bounded by the Newport-Inglewood Fault. In the
San Diegc area, the boundary swings offshore and largely
follows the Rose Canyon and Coronado Faults.
Sandwiched between Zone A and the outer Borderland, Zone
B is characterized by the lack of Mesozoic to Paleogene
sedimentary sequences and the presence of Franciscan-type
basement. The basement rocks of this zone are exposed in
the Palos Verdes Hills and on Santa Catalina Island, and
also have been attested to in the west Los Angeles Basin by
drilling and in the offshore area by dredging (Howell and
Vedaer, 1981). On the seismic profiles, the
Franciscan-type basement is characterized by a chaotic
reflection pattern and can be traced beneath the Neogene
sedimentary cover throughout most of this zone.
44
3.1,2 Outer Border land
The outer Borderland belt is by and large a duplicate of
the inner Borderland belt, consisting of an eastern Zone C
characterized by the presence of a thick Cretaceous
(Jurassic?) to Paleogene sedimentary wedge and a western
Zone D marked by the Franciscan-type basement (Figure 10
and 11). Unlike Zone A, there is no evidence showing that
i
al granitic basement underlies Zone C, though it has been
suggested (Crouch, 1981). The eastern margin of the
sedimentary wedge in Zone C is fairly well preserved and
deeply buried by Neogene sediments in Santa Cruz Basin
(Figure 11) . In San Nicolas Basin, this margin either
exhibits erosional features or becomes covered by the
volcanics. The western margin of the sedimentary wedge has
been disrupted and uplifted by Neogene tectonism and some
of the rocks are exposed on the northern Channel Islands
(Weaver, 1969) as well as on San Nicolas Island (Vedder and
Norris, 1963). A test well drilled on Cortes Bank
manifests that this sedimentary wedge also underlies the
Miocene sedimentary cover in that area (Paul and others,
1976). On seismic profiles, this wedge displays
well-stratified reflections all over Zone C (Figure 11).
The western limit of Zone C largely follows the west scarp
of San Miguel Island and Santa Rosa-Cortes ridge. Although
45
Figure 11: Line drawing of the seismic profiles across the
outer Borderland.
(see reference map below). The upper profile is
the original section. The lower figure is the
interpreted version.
Fe: Franciscan-type basement
Gr: Granitic basement
Om: Ophiolitic basement
Tv: Tertiary volcanics
K : Jurassic(?) to Cretaceous sequences
P : Paleogene sequences
M : Miocene sequences
Q : Pliocene to Recent sequences
PI: Lower to middle Pliocene sequences
P2: Upper Pliocene to Recent sequences
46
Patton Basin /■
Sea level Patton Ridge
Santa Rosa-
Cortes Ridge
Santa Cruz-
Catalina Ridge
Santa Cruz Basin
Sea ievel
Patton Fault
Santa Rosa-
Cortes Fault
Santa Cruz-
Santa Barbara
Fault
this boundary is often cut by faults, it is not a simple
tectonic line. Erosional features can be observed on top
of this wedge from place to place. It appears that the
west margin of the sedimentary wedge has gone through a
complex history which resulted in the present irregular
conf igurat ion.
West of Zone C, Zone D comprises the rest of the
Borderland all the way to the Pacific Ocean floor.
Basically this zone is made up of Franciscan-type deposit
covered by thin Neogene sedimentary sequences. It mainly *
forms a topographic high upon which several small basins
developed as a result of Neogene tectonism.
Franciscan-type rocks, such as greenschist, biueschist, and
greywacke, have been dredged and cored in some of DSDP
holes (Crouch, 1981). Chaotic reflection patterns
characteristic of Franciscan-type rocks are ubiquitous on
the seismic profiles in this zone.
Overall, the geologic terrains of the Borderland can be
distinguished in terms of the late Mesozoic to early
Tertiary rocks. Although having been modified by Neogene
tectonism, the geographic distribution of the pre-Neogene
sequences still retains a coherent configuration thac gives
us a fairly clear picture of the early Tertiary
48
paleogeography. This paleogeographic picture provides
clues to the early history of the Borderland and has been
employed to interpret the tectonic evolution of the
Borderland (Crouch, 1979; Howell and Vedder, 1981) which
will be further discussed afterwards.
3.2 NEOGENE STRUCTURAL FEATURES
The California Borderland has been a tectonically active
region throughout the late Cenozoic Period. The structural
features that mask the present Borderland area are mostly
attributed to Neogene tectonism. Since the Borderland is
strewn with complicated structural features, it is not easy
to elucidate them in an unambiguous way, although some
structural analyses have been proposed (Moore, 1969;
Howell, 1976a). In order to achieve a better perception of
the structural pattern of the Borderland, the writer has
attempted to look into the structural features in a
hierarchical fashion, i.e., in different scales (Figure
12). For the first step, the regional structural terrains
and the first-order structural features whose dimensions
are on the order of tens of Km will be investigated. Then
the second-order structures whose dimensions are on the
order of several Km will be displayed. In so doing, it is
hoped that the structural patterns and their
interrrelationships can be better documented.
49
Figure 12: Examples of the hierarchy of structural
features, Santa Cruz Basin.
50
First-order Structures
i \
A n ticlin o riu m S yn c lin o riu m
Second-order
^Structures * syncline
\ % anticline %
thrust
3.2.1 Northern terrain
As mentioned previously, the Borderland can be divided
into two structural terrains. The northern terrain,
comprising Santa Barbara Basin and the Northern Channel
Islands, is structurally a part of the Transverse Ranges.
The southern terrain which covers the rest of the
Borderland is structurally affiliated to the Peninsular
Ranges (Figures 13 and 14). The Santa Barbara Basin is the
offshore extension of the Ventura Basin and the Northern
Channel Islands are the extension of the Santa Monica
Mountains. For the first-order structures, the Santa
Barbara Basin is a broad syncline bracketed by the the
Santa Ynez Mountains to the north and the Northern Channel
Islands to the south. A number of E-W trending
second-order structures extend from the Ventura Basin into
the eastern and central part of the Santa Barbara Basin and
gradually die out to the west (Figure 14). Most of the
second-order structures tend to cluster on either limb of
the basin and the axial portion of the basin is relatively
intact.
The northern Channel Islands are, in general, an
anticlinorium. The second-order structurs on the islands
are mostly NW-SE trending. However, these second-order
structures are probably older features. Younger E-W
structures, such as Santa Cruz Island Fault and Santa Rosa
52
Figure 13: Structural framework of the Continental
Borderland, southern California.
First-order structures:
a. Santa Barbara Basin Synclinorium
b. Northern Channel Islands Anticlinorium
c. North Patton Ridge Anticlinorium
d. South Patton Ridge Anticlinorium
e. Santa Rosa-San Nicolas Ridge Anticlinorium
f. Nidever-Tanner Ridge Anticlinorium
g. Cortes Bank Anticlinorium
h. Santa Cruz Basin Synclinorium
i. San Nicolas Basin Synclinorium
j. Santa Cruz-Catalina Ridge Anticlinorium
k. San Clemente Ridge Anticlinorium
1. Catalina Ridge Anticlinorium
Basins:
1. Santa Barbara Basin
2. Patton Basin
3. Tanner Basin
4. Santa Cruz Basin
5. San Nicolas Basin
6. Catalina Basin
7. Santa Monica Basin
8. San Pedro Basin
9. San Diego Trough
53
STRUCTURAL FRAMEWORK
CONTINENTAL BORDERLAND
CALIFORNIA
0 SOKm
>
are Low
Los
. Angeles
k 1 %
San
?i)jego
Figure 14: Neogene structures of the Continental
Borderland, southern California.
Patterns:
Heavy dotted lines: terrain boundaries.
Dotted thick lines: anticlinoriums.
Dashed thick lines: synclinoriums.
First-order structures:
a. Santa Barbara Basin Synclinorium
b. Northern Channel Islands Anticlinorium
c. North Patton Ridge Anticlinorium
d. South Patton Ridge Anticlinorium
e. Santa Rosa-San Nicolas Ridge Anticlinorium
f. Nidever-Tanner Ridge Anticlinorium
g. Cortes Bank Anticlinorium
h. Santa Cruz Basin Synclinorium
i. San Nicolas Basin Synclinorium
j. Santa Cruz-Catalina Ridge Anticlinorium
k. San Clemente Ridge Anticlinorium
1. Catalina Ridge Anticlinorium
55
NEOGENE STRUCTURES
Continental Borderland
Southern California
b \.\V ■'■"***
N
M
\
Island Fault, cut through the NW-SE structures.
In general, both the first-order and second-order
structures in the northern terrain manifest the dominant
E-W structural grain. Most of these structures are
compressional features, although left-lateral transcurrent
movements have been noted too (Weaver, 1969b). The E-W
structural trend gradually dies out and is replaced by the
NW-SE trend in the western part of the terrain (Junger,
1979; Crouch and others, 19S4). Along with this change,
the intensity of deformation also varies such that the
eastern part of the terrain is packed with closely-spaced
second-order structures that fade away in the western part
of the terrain.
3.2.2 Southern terrain
The southern terrain is dominated by a NW-SE structural
grain which is consistent with the structural pattern of
the Peninsular Ranges. For the first-order structures,
this terrain is made up of a series of parallel structural
highs and lows (Figure 13). From west to east, the Patton
Ridge forms the first structural high and is flanked to the
east by the Patton-Tanner Low in which downwarped basins
such as Patton, Tanner, and Long are situated. The Santa
Rosa-Cortes Ridge makes up the second structural high and
57
is flanked to the east by the Santa Cruz-San Nicolas Low,
in which Santa Cruz, San Nicolas, and East Cortes Basins
are included. Further to the east is another structural
high, the Santa Cruz-San Clemente Ridge. Between the Santa
Cruz-San Clemente High and the continent is a structurally
low area which comprises a number of Neogene basins such as
Santa Monica, San Pedro, and Catalina Basins and San Diego
Trough. Because NW-SE structures are so well developed in
this area, it can be further subdivided into two structural
lows (Santa Monica- San Pedro, Catalina-San Diego) and one
intervening structural high (Catalina-Coronado).
In the southern terrain, most of the first-order
structures are compressional features aligned in the
NNW-SSE direction. They are generally made up of
anticlinoriums and sync 1inoriums arranged in en echelon
fashion. For instance, the Santa Rosa-Cortes High is
composed of Santa Rosa-San Nicolas Ridge, Nidever-Tanner
Ridge, and Cortes Bank anticlinoriums. The Cortes Bank
anticlinorium is shifted to the southeast relative to the
Nidever-Tanner Ridge anticlinorium which is also shifted to
the southeast relative to the Santa Rosa-San Nicolas Ridge
anticlinorium. Similar kinds of en echelon features can be
seen in other highs and lows. These compressional
structures are also accompanied by NW-SE trending faults,
58
such as Santa Cruz- San Clemente, Santa Rosa-Cortes, and
Patton fault zones (Fig. 14).
The second-order structures are more complicated in
nature (Figure 14). Generally speaking, they vary in
accordance with the basement geology and the first-order
structures. In Zone D of the outer Borderland, NW-SE
trending faults (about N 35 W) dominate the structural
grain. Most of them are strike-slip faults with some
vertical displacement. Although these faults are widely
distributed over the entire zone, most of them tend to
concentrate on the west limb of Santa Rosa-Cortes Ridge
(Santa Rosa-Cortes Fault Zone) and the east side of Patton
Ridge (Patton Fault Zone). Between the two fault ones, a
series of NNW-SSE to N-S trending normal faults cut through
the intervening region and are responsible for the
downwarping of Patton and Tanner Basins. A few
compressional features developed on Patton Ridge and on the
west side of Santa Rosa- Cortes Ridge. These features
generally have a NW-SE trend (about N 50 W) and are about
10 to 20 degrees further to the west relative to the NW
trending faults.
In Zone C of the outer Borderland, compressional
features become the dominant structural elements. Almost
all of these features are concentrated on the anticlinal
59
ridges along either side of this zone. NW-SE trending
folds and thrusts are superimposed on Santa Rosa-Cortes and
Santa Cruz-San Clemente Ridges in en echelon fashion. A
few WNW-ESE trending features cut across the zone and
separate Santa Cruz Basin from San Nicolas Basin. Some
strike-slip faults parallel to the NNW-SSE trending
first-order structures can also be found in the ridges but
they are overwhelmed by the compressional features.
In Zone B of the inner Borderland, both strike-slip
faults and compressional structures are prominent and they
often merge into one another. These features can be
grouped into two sets. One includes the NNW-SSE trending
faults, such as San Pedro Basin, San Diego Trough, and
Coronado Faults which are mainly strike-slip faults with a
minor amount of extension. Another set includes the NW-SE
trending faults and folds, such as Rose Canyon, Palos
Verdes faults and associated folds. These NW-SE trending
faults have both strike-slip and compressional components
and are largely parallel to the regional compressional
features. Most of the compressional features are developed
in the eastern half of the zone. To the west edge of this
zone, NW-SE faults, such as the Santa Cruz-Catalina and San
Clemente faults, are normal faults rather than
compressional features. Although the whole zone is
60
intensively penetrated by faults, most of the major faults
are concentrated in four zones, from west to east, Santa
Cruz-San Clemente, San Pedro Basin- San Diego Trough, Palos
Verdes-Corcnado, and Newport Inglewood-Rose Canyon Fault
Zones, as Legg and Kennedy (197S) suggested.
In summary, the Borderland can be divided into two
structural terrains. The nothern terrain which includes
Santa Barbara Basin and the northern Channel Islands is
characterized by the E-W structural grain which is well
developed in the eastern part of the terrain but gradually
fades out to the west. Most of the structural features are
compressional in nature, although left-lateral transcurrent
movements are also involved. The structural pattern
suggests that N-S compression is the dominant tectonic
stress in this area. The southern terrain which comprises
the rest of the Borderland is dominated by NNW-SSE to NW-SE
structural grains. For the first-order structures, this
area can be broken into a series of structural highs and
lows that are mostly made up of anticlinoriums and
synclinoriums arranged in en echelon fashion. The
second-order structures vary in accordance with the
basement geology and first-order structures. Compressional
features dominate Zone C and the eastern half of Zone B,
61
whereas transcurrent and extensional features dominate Zone
D and the western portion of Zone B. The overall
structural pattern suggests that NW-SE right lateral shear
with NE-SW convergence is the dominant tectonic stress in
the southern terrain.
62
Chapter IV
STRATIGRAPHIES OF THE BORDERLAND BASINS
Except for several small islands, most of the Borderland
is covered by sea water. Although the islands provide bits
and pieces of stratigraphic information, they do not
represent the stratigraphies of the basins. Bottom samples
offer clues to the sea floor geology but give very little
indication as to the stratigraphic sequence. A number of
test wells have been drilled in the Borderland but only a
few have been open to the public (Paul et al., 1976; Cook,
1979; Yeats and others, 1981; Howell and Vedder, 1983) and
none of them were drilled in the basins. So very little
direct information is available publically concerning the
stratigraphies of the Borderland basins.
In spite of the intrinsic difficulties, it is attempted
here to approach this task by incorporating the geologic
information with the seismic profiles. The basic idea is
to do sequence analysis for each basin to establish the
seismic reflection sequences. Then apply the geologic
information obtained from bottom samples, cores and
outcrops to the sequences and thereby infer possible
63
lithologic and biostratigraphic characteristics for the
sequences. In so doing, it is possible to produce a
reasonable hypothetical generalized stratigraphic column
for each basi'n. Certainly the statigraphic characteristics
may vary from place to place due to lateral facies
variations. It is not the purpose of this study to cover
all the stratigraphic details for the whole Borderland, but
to propose a representative stratigraphic column for each
basin so that a general picture of the stratigraphies of
the basins with some knowledge of their differences and
relationships can be obtained (Figure 15).
4.1 PATTON AND TANNER BASINS
In Zone D of the outer Borderland, Patton and Tanner
Basins share comparable stratigraphic features (Figure 16).
Their sediments are based on Franciscan-type rocks,
possibly Mesozoic to early Tertiary in age. Early to
middle Miocene sequences which consist of diatomaceous
shales, volcaniclastics, and turbidites unconformably
overlie the basement. These sequences are not confined to
the basins but are widely spread over the entire area
(Crouch, 1981). Unconformably overlying the early to
middle Miocene sequences are the middle to late Miocene
rocks which are iithologically similar to the underlying
strata. These sequences are much more restricted in
Figure 15: Stratigraphic schemes of the Borderland basins.
Fe: Franciscan-type basement
Gr: Granitic basement
Om: Ophiolitic basement
Tv: Tertiary volcanics
K : Jurassic(?) to Cretaceous sequences
P : Paleogene sequences
M : Miocene sequences
Q : Pliocene to Recent sequences
PI: Lower to middle Pliocene sequences
P2: Upper Pliocene to Recent sequences
65
Santa
Barbara
\ Santa
\ \ C r u *
\
Patton
\Tanner
\\pkk-
0
L
50 Km
STRATIGRAPHIC SCHEMES
CONTINENTAL BORDERLAND BASINS
Santa SOUTHERN CALIFORNIA
Monica
San
Pedro
Mu
Catalina/
San
Diego
igure 16: Stratigraphic column for Patton and Tanne
Basins. Thicknesses are relative in the
diagram.
Patton and Tanner Basins
Schematic stratigraphic column
n r\__rl
r \__ rl -A
v vv
-A- _A_ _A_
Upper Pliocene to Recent Sequence
mass-flow deposits and hemipelagics
max. thickness about 300 m.
Conform ity w ith minor discordance
Lower to Middle Pliocene Sequence
mass-flow deposits
max. thickness about 600 m.
Basin edge unconform ity
Middle to Upper Miocene Sequence
f o s s i1ife ro u s shales and v o lc a n ic la s tic s
max. thickness about 800 m.
Unconformi ty
Lower to Middle Miocene Seauence
Marine c la s tic deposits and v o lc a n ic la s tic s
max. thickness about 1400 m.
Uncon formi ty
Mesozoic to E arly Te r t ia r y Basement
Francis can-type melange deposits
68
distribution than the early to middle Miocene rocks and
mostly fill in the basins. Overlying the Miocene strata
are the Pliocene to Recent clastic deposits. These late
Neogene sediments are confined to the basins and are
believed to be mainly hemipelagic and mass-flow deposits.
A slight discordance may separate the late Pliocene and
younger strata from the early to middle Pliocene sequences.
4.2 SANTA CRUZ AND SAN NICOLAS BASINS
In Zone C of the outer Borderland, Santa Cruz and San
Nicolas 3asins have comparable stratigraphic sequences
(Figure 17). The basement character is basically unknown,
although possibly ophiolitic as well as granitic crusts
have been suggested (Howell and Vedder, 1981; Crouch,
1951). Some Mesozoic plutonic rocks and associated
metamorphic complex are exposed underlying the Cenozoic
sedimentary sequences on Santa Cruz Island, which most
likely represent a sliver of the basement rocks (Hill,
1976).
69
Figure 17: Stratigraphic column for Santa Cruz, San
Nicolas, and possibly Santa Barbara Basins.
Thicknesses are relative in the diagram.
70
Santa Cruz and San Nicolas Basins
(Santa Barbara Basin?)
Schematic stratigraphic column
vy
Upper Pliocene to Recent Sequence
mass-flow deposits and hemipelagics
max. thickness about 600 m.
Basin edge unconform ity
Lower to middle Pliocene Sequence
mass-flow deposits
max. thickness about 800 m.
Basin edge unconform ity
Miocene Sequence
fossi 1 i ferous marine shales,
v o lc a n ic la s tic and t u r b i d i t i c deposits
max. thickness about 1800 m.
Unccnformi ty
Paleogene Sequence
shallow to deep marine c la s tic deposits
max. thickness about 1600 m.
Conformi ty
Jurassic? to Cretaceous Sequence
Coarse-grained mass-flow deposits
max. thickness about 3000 m.
Conform ity w ith minor discordance
Mesozoic Basement
o p h io litic ? p a r tly g ra n itic ?
or melange?
71
Overlying the acoustic basement is a thick sequence of
Cretaceous (possibly Jurassic) to Paleogene strata which
forms a sedimentary wedge that thins and onlaps the
basement to the east and thickens to the west (Figure 11).
A part of this sequence is exposed on the northern Channel
Islands (Weaver, 1969c; Doerner, 1969; Weaver and Doerner,
1969) and San Nicolas Island (Vedder and Norris, 1963), and
has been found in drill holes at Cortes Bank (Paul and
others, 1976). Both the outcrop and core data suggest a
spectrum of shallow to deep-water deposits that owe their
sources mainly to the continent (Weaver and Doerner, 1969;
Cole, 1977; Abbott and Smith, 1978; Howell and Link, 1979;
Abbott and others, 1983; Bartlings and Abbott, 1983).
Although minor hiatuses can be found in these rocks, they
essentially represent a continuous sequence without any
significant discordance. The thickness of the total
sequence may reach 3000 m near its western margin.
Miocene strata are the most widespread rocks in this
zone. They overlap the Paleogene rocks and onlap the
basement to the east. For most of the area, they form a
drape-like deposit of fairly uniform thickness, covering
all the topographic irregularities, basins, troughs,
ridges, as well as banks. Dredge samples indicate that a
great portion of these deposits are diatomaceous shales
72
equivalent to the Monterey-type rocks on land. Volcanic
and volcaniclastic rocks are also very abundant in the
Miocene strata, especially along the Santa Cruz- San
Clemente Ridge. Some of these rocks are exposed on Santa
Cruz, Santa Rosa, and San Clemente Islands (McLean and
others, 1976; Vedder and Howell, 1976a) Many of the
volcaniclastic strata are believed to be submarine fan
deposits (McLean and Howell, 1983). Both the volcanic and
volcaniclastic rocks often interfinger with the
diatomaceous shales.
The post-Miocene rocks are quite different from the
older rocks in that their distributions are mainly confined
to the basins. They generally fill in the basins as
flat-lying layers onlapping the flanks of the basins
(Figure 11) . They are believed to be mainly turbiditic
deposits, slump beds and hemipelagics. Two units can be
recognized in these deposits. The lower unit is believed
to be early to middle Pliocene in age, and the upper unit
late Pliocene to Recent in age.
73
4.3 SANTA BARBARA BASIN
Santa Barbara Basin has, in general, the same
stratigraphic sequences as Santa Cruz and San Nicolas
Basins. However, the relative thicknesses are quite
different. The Neogene sequences are very thick in Santa
Barbara Basin, about 3000 to 4000 m (Figure 2). The
thickness increases appreciably toward the east where the
post-Miocene sequences have accumulated to more than 4000 m
(see structure cross sections of Weaver, 1969a). The
pre-Neogene sequences are deeply buried by the Neogene
sediments and their thickness i-s actually unknown.
However, Cretaceous rocks have been reported underlying the
Miocene sequences in the western part of the basin around
the Point Conception area (Cook, 1979), and the pre-Miocene
sequences on the northern Channel Islands can be traced to
the southwest part of the basin on the seismic profiles.
It is beli.eved that Mesozoic to Paleogene sequences at
least underlie a part of the basin, but their thickness is
much reduced.
74
4.4 SANTA MONICA, SAN PEDRO, AND CATALINA BASINS, AND SAN
DIEGO TROUGH
In Zone B of the inner Borderland, Santa Monica, San
Pedro and Catalina Basins and San Diego Trough share
comparable stratigraphic characteristics (Figure 18 and
19), in spite of their variation in sediment thickness.
They are based on Franciscan-type rocks and covered with
Miocene to Recent sediment. The basement rocks crop out on
the Palos Verdes Hills and Santa Catalina Island where they
are known as Catalina schist (Woodford, 1924). Similar
kinds of rocks can be traced all over the area on
seismograms and some of them have been documented by
dredging (Howell and Vedder, 1981). Overlying the basement
are the widely distributed Miocene sequences. A portion of
the Miocene rocks are exposed on Palos Verdes Hills, Santa
Barbara, and Santa Catalina Islands, where they show up as
volcaniclastic rocks that interfinger with Monterey-type
shales (Conrad and Ehlig, 1983; Vedder and Howell, 1976a).
Dredge samples also indicate that the same kind of
lithologic associations occur in the offshore area. In San
Diego Trough, the Miocene sequences may reach 1500 m in
thickness, whereas in Catalina and San Pedro basins, their
thickness is generally less than 500 m. In Santa Monica
Basin, the Miocene deposits only cover the southeastern
corner of the basin and are missing in the center of the
75
Fiqure 18: Stratigraphic column for Santa Monica ana San
Pedro Basins. Thicknesses are relative m the
diagram.
76
Santa Monica and San Pedro Basins
Schematic stratigraphic column
_y\_ _n
Upper Pliocene to Recent Sequence
Slope to deep-sea mass-flow deposits
max. thickness about 1300 m.
Conform ity w ith minor discordance
Lowe'- to Middle Pliocene Sequence
S he lf to deep-sea c la s tic deposits
max. thickness about 1200 m.
Unconformi ty
Middle to Upper Miocene Sequence
diatomaceous shales and v o lc a n ic la s tic s
max. thickness about 700 m.
’Jnconformi ty
Mesozoic to Early T e r tia r y Basement
Franciscan-type melange deposits
p a r tly covered by Miocene v o lca n ics.
77
Figure 19: Stratigraphic column for Catalina Basin and San
Diego Trough. Thicknesses are relative in the
diagram.
78
Catalina Basin and San Diego Trough
Schematic stratigraphic column
Upper Pliocene to Recent Sequence
t u r b i d i t i c deposits
max. thickness about 400 m.
Conform ity w ith minor discordance
Lower to Middle Pliocene Sequence
t u r b i d i t i c and hemi pel agio deposits
max. thickness about 300 m.
Basin edge unconform ity
Middle to Upper Miocene Sequence
diatomaceous shales, v o lc a n ic 1a s tic
and mass-flow de po sits,
max. thickness about 800 m.
Unconformi ty
Lower to Middle Miocene Sequence
Shallow to deep marine c la s tic deposits
vol earn’ d a s ti cs and diatomaceous shales
max. thickness about 1000 m.
Unconfo rmi ty
Mesozoic to E arly T e r tia r y basement
Franciscan-type melange depoists.
79
basin. An unconformity can often be found in the middle
of the Miocene sequences. Overlying the Miocene strata as
well as the basement are the Pliocene to Recent deposits.
Unlike the Miocene sequences, the distribution of these
young deposits is pretty much delimited to the basins.
They are believed to be epiclastic sediments derived mainly
from the continent. In Catalina Basin, these young basin
deposits are fairly thin, whereas in Santa Monica and San
Pedro Basins, they can attain 3000 m in thickness.
In summary, the Borderland basins share comparable
stratigraphic characteristics in spite of their differences
in sediment thickness and distribution. Patton, Tanner,
Catalina, Santa Monica, and San Pedro Basins and San Diego
Trough are all floored with Franciscan-type basement
covered with Miocene to Recent sediments. Santa Cruz, San
Nicolas, and Santa Barbara Basins are characterized by
thick Mesozoic to Paleogene sequences draped by Miocene
strata and filled in with Pliocene to Recent sediments.
Although the rock properties vary from place to place,
generally speaking, Mesozoic to Paleogene sequences are
composed of shallow to deep water siliciclastic deposits.
The Miocene sequences are dominated by volcaniclastic and
biogenic sediments. The Pliocene to Recent sequences are
80
dominated by deep-water mass-flow deposits. Based on the
available biostratigraphic information, a preliminary
correlation among the stratigraphic columns of the basins
is proposed as shown in Figure 15.
81
Chapter V
SEDIMENTATION OF THE BORDERLAND BASINS
As mentioned in the last chapter, the distribution of
Mesozoic to Miocene sequences in the Borderland are not
controlled by the configuration of the present-day basins
(Figure 11). Only the Pliocene to Recent deposits are
confined to the basins, in which they fill in the lows of
the depressions as flat-lying sequences onlapping the
Miocene and older rocks. The basin-fill deposits have
well-defined areal distribution and are believed to have
been deposited by the sedimentary processes intrinsic to
the basins. Hence the facies distribution of these
deposits will undoubtedly reflect the depositional
processes in the basins. Moreover, these deposits are
relatively surficial sequences, for which the reflection
profiles yield the best coverage and resolution.
Therefore, it is very appropriate and worthwhile to perform
facies analysis on the basin-fill deposits in order to
depict the depositional systems and sedimentation history
of the Borderland basins.
82
5.1 DEPOSITIONAL SYSTEMS AND SEISMIC FACIES
The methods and criteria for facies analysis have been
elucidated and tabulated in many papers (e.g., Brown and
Fisher,1977; Mitchum and others, 1977b; Sangree and
Widmier, 1977). However, different terrains have different
geologic characteristics. The facies criteria applicable
to one area do not necessarily work for another area. For
the California Continental Borderland which is an active
continental margin complicated by wrench tectonism, deep
marginal basin sedimentation is the dominant
sedimentological feature. In order to demonstrate this
type of depositional system, the writer has attempted here
to subdivide the seismic facies into three major categories
(Figures 20 and 21):
5.1.1 Shelf facies
These includes all the shallow-water facies deposited in
the area between the coastline and the shelf break. They
are dominated by parallic deposits which are characterized
by reflections of low discontinuity and variable amplitude
on the seismograms.
83
Figure 20: Diagrammatic deposational settings and facies
of the continental margin, (after Brown and
Fisher, 1977).
84
Shelf
St! StUS
CONTINENTAL SHELF
-A Facies
, / » : >jt\Y 8 0 HOM St T B E us 5 K f f -
'( / m % n iw fL d s m r i^ 'M rJ
CONTINENTAL SLOPE
V OEtP-SEA FAN V
Basina!
4< ' ' —» -
t> - _
ADYSSAL PLAIN —
85
Figure 20: Facies analysis on Seismic Profiles,Santa
Monica Basin.
{see reference map below). Deep-penetration
profiles. The vertical scale is two-way travel
time. The upper profile is the original stacked
section. The lower figure is the interpreted
version. PI: Lower to middle Pliocene
sequences; P2: Upper Pliocene to Recent
sequences.
86
NISV8 VOINOJAI V1NVS
5.1.2 Slope facies
These include all the facies.deposited between the shelf
break and deep basins. They are dominated by hemipelagic
sediment with minor amounts of mass-flow deposit.
Submarine canyons and slump beds are very common. On the
seismograms, they are recognized by reflections of low
amplitude and frequency, and the presence of chaotic slump
features and deep canyons.
5.1.3 Basinal facies
These include all the facies deposited in the deep
basins. They are mostly dominated by turbiaitic deposits,
but a hemipelagic component can also be important. On the
seismograms, they are characterized by reflections of
variable continuity and amplitude.
5.2 SUBMARINE FAN SYSTEMS AND SEISMIC FACIES
Since the Borderland basins are dominated by deep-sea
mass-flow deposition, the basinal facies actually
contribute more than eighty percent of the total
sedimentary sequences. It is worth further breaking down
the basinal facies into more detailed facies subdivisions
if possible. In fact, most of the basinal facies are
composed of coalesced submarine fan-channel complexes. The
88
depositional systems of the submarine fan deposits have
been fairly well understood as a result of studies in the
last two decades, and a number of models have been proposed
(Rupke, 1978; Nardin and others, 1979a; Normark and others,
1983) Seismic reflection characteristics of the different
facies of the submarine fan deposits have also been
tabulated and used for interpretation (Nardin, 1983; Kolia
and others, 1984). However, neither the depositional
systems of submarine fan complexes nor the seismic
reflection characteristics are unequivocal. It is not the
writer's intention to get into the detailed arguments about
these two subjects. Nevertheless, in order to vindicate
the validity of the facies analysis, it is imperative to
briefly elucidate the depositional model and reflection
characteristics used in this study.
5.2.1 Fan settinqs
In spite of the variations in details, it is generally
accepted that four subdivisions of the submarine fan system
can be distinguished (Figure 21 and 22):
89
Figure 22 Depositional settings of submarine fan.
a. American model (after Normark, 1978)
b. European model (after Rupke, 1S78).
90
Upper Fan
- i - V, > v K
Conlinental Sjop®,
l l l l u i h j M 1 111 L- u - i *
V \ Mid F an
Abandoned
Suprafon
Supra fan Lower Fan
K i lom«1ers
KO
Basin plain
I I I Mainly clay/marl
Inner fan------' ------1
b
' V Main sand accumulation
Middle fan : ' j
Outer fan L ~ J 4 sand
Pelagic deposits J Mainly clay/marl
A. Upper (or Inner) fan:
the area around the apex of the fan just in front of
the feeding canyon, generally having the steepest slope,
characterized by large and deep channels and sharp
lateral facies changes.
B. Middle fan
the area around the medial portion of the fan,
generally having a moderate slope, characterized by
abundant shallow distributary channels and less lateral
. facies variations.
C. Lower (or Outer) fan
the area around the lower fringe of the fan, slope
generally small, characterized by lateral facies
homogeneity and the lack of prominent channels.
D. Basin plain
deep basin area beyond the dominance of turbidity
current activities. generally no prominent slope,
characterized by the hemipelagic and thin very distal
turbiditic deposits.
92
5 . 2 . 2 Fan f a c i e s
For the Borderland basins, the turbiaitic deposits are
restricted to the limited basinal area (only 15% of total
Borderland area, Trosper, 1983), such that the basin plain
deposits are hardly distinguishable from the outer fan
deposits. Therefore, based on the characteristics of the
subdivisions of submarine fans, three corresponding seismic
facies can be recognized (Figure 21)
1. Upper fan facies
Characterized by deep channels and sharp lateral
variations. Chaotic reflections are often associated.
2. Middle fan facies
Characterized by reflections of low continuity and
variable amplitude.
3. Lower fan (including basin plain) facies
Characterized by reflections of high continuity and
uniform amplitude.
Like many other classifications, these facies
subdivisions are separated arbitrarily and are transitional
to one another. They are determined in a qualitative and
relative sense so that the depositional systems of the fan
complex can be displayed. The facies maps thus obtained
provide clues to the depositional processes and the
93
potential source terrains for the basin sediments. However,
no absolute implications on the lithology of different
facies can be made.
5.3 FACIES PATTERNS OF BASIN-FILL SEQUENCES
For the nine basins in the studied area, the basin-fill
sequences can be divided into two units. The lower unit is
the Lower to middle Pliocene (PI) and the upper is the
Upper Pliocene to Recent (P2). Facies maps featured with
isopachs for both PI and P2 are made for each basin
(Figures 23 to 40) and the sedimentation pattern and
history thereby briefly discussed.
5.3.1 Patton Basin
As shown in Figures 23 and 24, lower fan and basin plain
facies dominate the basin. From the facies pattern, it
seems that Patton Ridge has been the major source terrain
for the sediment. Santa Rosa-San Nicolas Ridge supplied
only a minor amount of sediment to PI but the sediment
supply increased for P2 as shown by the newly developed fan
at the northeastern corner. Based on the facies
distribution and the reflection characteristics, it is
believed that hemipelagic and fine-grained turbiditic
deposits dominate the basin-fill sequences.
94
F ig u r e 23: D e p o s i t i o n a l system s o f th e Lower t o M id d le
P lio c e n e sequences ( P I ) , P a tto n B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
95
PATTON BASIN
10Km
F ig u r e 24: D e p o s i t i o n a l system s o f th e Upper P lio c e n e t o
R ecent sequences (P2), P a tto n B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
97
z d
UJMOL
C
I
C 5
0 -
Nisva N O llV d
5.3.2 Tanner Basin
Tanner was actually composed of two separate basins
during the early to middle Pliocene, as shown in Figure 25
Continued subsidence at the waist of the basin lowered the
barrier between the two basins and gave rise to a single
basin at later time (Fig. 26). Garrett Ridge situated to
the southwest of the basin and the Nidever Bank to the
northeast seem to have been the major source for the
sediment of both Pi and P2. Tanner Bank situated to the
southeast contributed only a small amount of sediment. The
facies distribution and the reflection characteristics
indicate that the lower fan and basin plain facies dominate
the basin-fill sequences which are mainly composed of
fine-grained turbidites and hemipelagics. Box core and
high resolution seismic stratigraphic studies support this
conclusion (Gorsline and others, 1S68; Reynolds, 19S4).
5.3.3 Santa Cruz Bas in
As shown in Figures 27 and 28, the basin-fill sequences
appear dominated by mass-flow deposits. Santa Rosa-San
Nicolas Ridge lying to the west of the basin evidently have
been the major source for the sediment. Santa Barbara
Island situated to the southeast of the basin contributed a
small portion. Although different fan facies can be
distinguished, no conspicuous canyon-fan-basin systems
99
F ig u r e 25: D e p o s i t i o n a l system s o f th e Lower t o M id d le
P lio c e n e sequences (P I) , T anner B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
100
TANNER BASIN
\
\
N Id ever
Bank
Tanner
Bank
T'
10Km
-j
F ig u r e 26: D e p o s i t i o n a l system s o f th e Upper P lio c e n e to
R ecent sequences ( P 2 ) , Tanner B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
102
t a n n e r
^NitJever
\ . ^
b a s in
N
F ig u r e 27: D e p o s i t i o n a l system s o f th e Lower t o M id d le
P lio c e n e sequences ( P I ) , Santa C ruz B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1500-m isobaths.
104

F ig u r e 28: D e p o s i t i o n a l system s o f th e Upper P lio c e n e to
Recent sequences (P2), Santa Cruz B a s in .
Patterns:
Very heavy dots: Slope facies
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1500-m isobaths.
106
SANTA CRUZ BASIN
*
10Km
O '
N
k
Santa
Barbara
^xlsian d
)
107
(Nardin and others, 1979a; Gorsline, 1980) can be
recognized. It seems that the mass-flow deposits might
have been fed by a number of small channels draining down
the slope from Santa Rosa-San Nicolas Ridge, or by sediment
failures on the slope. High resolution seismic reflection
studies on Quartenary deposits support this form of process
(Nardin and others, 1979b; Field and Edwards, 1980). Based
on the reflection characteristics, it is believed that
fine-grained turbidites and hemipelagics dominate the basin
sediments, whereas slump beds might dominate around the
base-of-slope margin of the basin.
5.3.4 San Nicolas Basin
San Nicolas Basin appears to be filled mainly with
mass-flow deposits as shown in Figures 29 and 30. The
major supply of sediment came from source terrain lying to
the northwest of the basin, which includes San Nicolas
Island Bank and Nidever Bank. Based on high resolution
data, Reynolds (1984) was able to document a complicated
bifurcating channel system at the northwest corner of the
basin, which has been responsible for funneling the
sediment into the basin. Niaever-Tanner Ridge and San
Clemente Ridge on either side of the basin are the
subordinate source terrains which contributed to the basin
mainly through small individual channels on the slope.
108
F ig u r e 29: D e p o s i t i o n a l system s o f th e Lower t o M id d le
P lio c e n e sequences ( P I) , San N ic o la s B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m) . See location in Figure 1.
Dashed lines are the 1000-m isobaths.
109
z
( / )
<
CO
( / )
<£
_ l
o
o
&
z
<
< n
F ig u r e 30: D e p o s i t i o n a l system s o f th e Upper P lio c e n e t o
R ecent sequences (P2), San N ic o la s B a s in .
Patterns:
Very heavy dots: Slope facies
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
I l l
CO
<
CO
t n
<
o
o
z
z
<
C / 5
Small fan systems might have formed on the eastern side of
the basin where more concentrated channel flows might have
existed (Reynolds, 1984). Slump deposits are very common
on the western side of the basin. In the center of the
basin, hemipelagic and distal turbiditic deposits appear to
be the dominant facies in terms of reflection
characteristics.
5.3.5 Catalina Basin
Catalina is a large and starved basin as compared with
other basins in the Borderland. In the early to middle
Pliocene (Figure 31), the depocenter was mainly at the
northwestern part of the basin where sediment derived from
Catalina Rdge, Santa Barbara Island, and San Clemente Ridge
accumulated in several small deep holes. To the south, a
minor amount of sediment was brought in from Fortymile Bank
and from San Pedro Shelf after spilling over Catalina
Ridge. Reflection characteristics indicate that
hemipelagic and fine-grained turbiditic deposits make up
the essential component of the basin-fill. No distinct fan
systems can be recognized in these deposits, although the
sediment aprons derived from Catalina Ridge and San Pedro
Shelf may appear like fans.
F ig u r e 31: D e p o s i t i o n a l system s o f th e Lower t o M id d le
P lio c e n e sequences ( P I ) , C a t a lin a B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100 »
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
114
C A T A L IN A B A S IN
San
Pedro
^ Shelf
m /
\
Santa '
Barbara'
Island
&
s mile
*
( "J
Ol
P i
San Clem
0 10 Km
-j
F ig u r e 32: D e p o s i t i o n a l system s o f th e U p p e r P lio c e n e to
R ecent sequences (P2), C a t a lin a B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
116
CATALINA BASIN
San
Pedro
S h elf
$ a
Cfe
m
Santa ^
Barbara (
Island
\ b ) b M
P
The depositional systems changed quite a bit in the
Piio-Pleistocene (Figure 32). Due to tectonic activities,
the depositional area in the northwestern part of the basin
shrank and received only a small amount of sediment from
local highs. The sediments spilling over Catalina Ridge
spread over half of the basin to form a large fan system
and constitute the major portion of the basin-fill. Based
on the reflection characteristics, turbiditic deposits
dominate the basin-fill sequences, whereas hemipelagic
deposits may also be dominant in some parts of the basin.
5.3.6 Santa Barbara Basin
As shown in Figures 33 and 34, Santa Barbara Basin is
filled with a thick sequence of post-Miocene sediments.
The reflection characteristics of the basin-fill deposits
show that channeling and slump features are very common all
over the basin (Figure 2) (Thornton, 1981). No distinct
fan subdivisions can be distinguished . It seems that the
basin has been dominated by the base-of-slope deposition
(Gorsline, 1980) since the Pliocene. Based on the facies
distribution and sediment thickness, it is clear that the
Santa Barbara Coast and the Oxnard Shelf have been the
major source terrains for the basin sediment. The
reflection characteristics indicate that mass-flow deposits
118
F ig u r e 33: D e p o s i t i o n a l system s o f th e -Lower t o M id d le
P lio c e n e sequences ( P I ) , S anta B a rb a ra B a s in .
Patterns:
Dots : Slope facies
Lines: Basinal facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 200-m isobaths.
119
120
SANTA BARBARA BASIN
B a r b a r a
S o n t a
C o a s t
-^--rrV: \ •-* *-* ,v.‘ v» • • . . # •
• J . i > < 1 ' V f * / ’ • • • » • < . ' • • * . % * . ' • • • .
v.-.'.vlv.-b.-iv.o
Islands
Oxnard
Shelf
F ig u r e 34: D e p o s i t i o n a l syste m s o f th e Upper P lio c e n e t o
R ecent sequences (P2), Santa B a rb a ra B a s in .
Patterns:
Dots : Slope facies
Lines: Basinal facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 200-m isobaths.
121
SANTA BARBARA BASIN
Santa Barbara Coast
Oxnard
Shelf
10Km
P :
Northern Channel Islands
tv)
fO
dominate the basin-fill sequences, which has been supported
by core studies (Thornton, 1981).
5.3.7 ' Santa Monica 3asin
Santa Monica Basin is filled with a thick sequence of
Pliocene to Recent sediment. As shown in Figure 35, the
basin was not entirely a deep basin but included a large
portion of shelf to slope settings in the early to middle
Pliocene (Figure 21). The basinal facies are restricted to
a small region in the southern part of the basin, in which
no distinct fan systems can be recognized. Volumetrically
the shelf deposits made up the major portion of the
basin-fill and the slope to basinal facies occupy a minor
portion. This indicates that the basin was at its early
stage of subsidence and the sediment input was large enough
to fill a large portion of the basin to maintain the
shallow water environment. Based on the facies
distribution, the Oxnard-Santa Monica coast was the
sediment source for the basin deposits.
The depositional systems have changed quite a bit since
the late Pliocene. As shown in Figure 36, submarine fan
systems are well developed in the young basin-fill
sequences. Four distinct fan systems can be distinguished,
in which Hueneme fan is the largest, Mugu the second, Dume
the third, and Santa Monica the smallest. Based on the
123
F ig u r e 35: D e p o s i t i o n a l system s o f th e Lower t o M id d le
P lio c e n e sequences ( P I ) , S anta M onica B a s in .
Patterns:
Heavy dots: Shelf facies
Samll dots : Slope facies
Lines: Basinal facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 750-m isobaths.
124
m O l
. . . .
* * '^.v
« / e
iSBOQ BOIUO|/\| BlUeS
k
r
j
Nisva VOINOIAI V1NVS
125
F ig u r e 36: D e p o s i t i o n a l system s o f th e U pper P lio c e n e t o
R ecent sequences ( P 2 ) f Santa M onica B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 750-m isobaths.
126
SANTA MONICA BASIN
0
L
Hueneme
Mugu
©cuD
^ ' ranyon
Santa
Monica
any.on
£
I l',l
: q>'V
v S i M m .
W M2, ' f .
' M M l
W fi'i'
m m
10 Km
-j
facies pattern, it seems that the sediment was supplied
from the north (Oxnard area) by a coastal drift system
pretty much similar to what we have today. Sediment
spilled from Los Angeles Basin might have also contributed
to the basin, especially through Santa Monica Canyon.
Based on the reflection characteristics, it seems that
turbiditic deposits, both coarse- and fine-grained facies,
cover the entire basin. These P2 deposits have been
further studied in detail in terms of high resolution data
(Junger and Wagner, 1977; Nardin, 1981, 1983). Three
subunits can be distinguished and their depositional
systems have been well displayed.
5.3.8 San Pedro Basin
Like Santa Monica Basin, San Pedro Basin is also filled
with a thick sequence of post-Miocene sediments. Because
the quality of deep-penetration profiles across the basin
is not good enough to warrant a decent facies analysis for
the old basin-fill deposits, only the isopach map of PI is
shown in Figure 37. It seems that San Pedro Basin was only
a part of an arcuate trough connecting the Palos Verdes
area to the San Pedro area. If the basin received
sediments from the continent via the trough, Palos Verdes
and San Pedro coastal areas would be equally important as
the source for the basin sediment.
128
Figure 37: Isopach map of the Lower to Middle Pliocene
sequences (PI), San Pedro Basin.
Patterns:
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 750-m isobaths.
129
SAN PEDRO BASIN
N
10Km
i
San
~Jm P e ^ r°
* Shelf
130
F ig u r e 38: D e p o s i t i o n a l system s o f th e Upper P lio c e n e to
R ecent sequences (P2), San Pedro B a s in .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 750-m isobaths.
131'
SAN PEDRO BASIN
Redondo
^Canyoi
10Km
i
For the late Pliocene to Recent deposits, the picture is
quite different (Figure 38). The whole basin is actually
covered by a single fan system fed by Redondo Canyon. A
large amount of sediment has been dumped into the basin.
Based on the high resolution profiles, Nardin{1981) was
able to divide these deposits into three subunits, all of
which are mainly composed of turbidites. This conclusion
is consistent with the writer’s interpretation in terms of
additional high-quality reflection profiles.
5.3.9 San Diego Trough-
As shown in Figures 39 and 40, San Diego Trough has been
dominated by the La Jolla fan system since the Pliocene. A
small amount of sediment might have been supplied by the
Coronado Bank during the early to middle Pliocene and by
spillover from the Gulf of Catalina during the late
Pliocene to Recent. Based on the reflection
characteristics, fine-grained turbiditic deposits dominate
the old basin-fill sequences, whereas coarse-grained
turbiditic deposits might gain some weight in the young
basin-fill sequences. Clearly the La Jolla Fan system has
been growing throughout Plio-Plestocene and sediments have
spilled out of the trough to feed the San Clemente Basin
(Normark and Hess, 1979) and possibly Catalina Basin too.
13 3
F ig u r e 39: D e p o s i t i o n a l syste m s o f th e Lower t o M id d le
P lio c e n e sequences ( P I ) , San D ie g o T ro u g h .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m) . See location in Figure 1.
Dashed lines are the 1000-m isobaths.
134
SAN DIEGO TROUGH
w y x - i - W
R
L.3
Jolla
Canyon
N
m .
• * V «•
v
. |\\ Coronado
s^ll\V.Bank
9 m m \
\ ^ o 1 -
10Km
135
F ig u r e 40: D e p o s i t i o n a l system s o f th e Upper P lio c e n e t o
R ece n t sequences (P2), San D ie g o T ro u g h .
Patterns:
Heavy dots: Upper fan facies
Small dots: Middle fan facies
Dashes: Lower fan and basin plain facies
Arrows: Inferred sediment dispersal pattern
Isopachs in 100 msec (rouhly equivalent to 100
m). See location in Figure 1.
Dashed lines are the 1000-m isobaths.
136
SAN DIEGO TROUGH
G u lf Of
C a ta lin a
La Jolla
^ ^Canyon
a * . • • i * A •
R
v.v • ' . • ■ • . • ; . ■ \ v ; , v
m m m m
10Km
137
5.4 SEDIMENT ACCUMULATION RATES
Based on the isopach maps of the basin-fill sequences,
the sediment budget can be roughly estimated. Assuming
that the average velocity of the basin sediment is about
2000 m/sec, the thickness of the sediment in milliseconds
is equivalent to the thickness in meters. The volume of
sediment is calculated by multiplying the area between two
contours with the mean value of the two contours. Assuming
that the specific weight of the sediment is 1.6, the total
weight of the basin sediment can be estimated by
multiplying the volume with density.
Although no good geochronologic data is available to
give a good time control on the basin-fill sequences, the
time spanned by PI and P2 are believed to be 2.5 and 2 m.y.
respectively (see discussions in the late chapter). Based
on these time span estimates, the sediment accumulation
rates of each basin is calculated and displayed in Tables 1
and 2, in comparison with the Holocene rates estimated by
Schwalbach (1582)’. Owing to the uncertainties in the
assumptions, the accumulation may have an error range about
50 %. The numbers in the table only provide a first-step
approximation and a rough picture about the variations of
the basin sedimentation.
138
TABLE 1
Total accumulation rates of the Borderland Basins.
Basi n
Accumulation rates (10 tons/yr)
PI P2 Holocene
Patton 0.06 0.08
Tanner 0.13 0.10 0.13
Santa Cruz 0.24 0.11 0.46
San Nicolas 0.42 0.21 0.33
Catali na 0.22 0.16 0.27
Santa Barbara 0.51 0.93 2.35
Santa Monica 0.64 1.09 1.40
San Pedro 0.24 0.19 0.36
San Diego 0.08 0.16 0.18
139
TABLE 2
U n i t a c c u m u la tio n ra te s of th e B o r d e r la n d B a s in s ,
Bas i n
2
Accumulation rates (mg/cm /yr)
PI P2 Hoiocene
Patton 8 9
Tanner 27 14
o
CM
i
ID
Santa Cruz 24 13 20-40
San Nicolas 22 14 10-21
Catali na 14 10 10-27
Santa Barbara 26 40 80-130
Santa Monica 43 54 40-90
San Pedro 26 27 30-90
San Diego 12 13 10
140
As shown in Table 1, Patton and Tanner Basins have the
lowest total sediment accumulation, Santa Cruz, San
Nicolas, and Catalina Basins have a higher total sediment
accumulation because of their large dimensions. Santa
Monica and Santa Barbara Basins are the major sediment
traps as shown by their high total sediment amounts. San
Pedro Basin and San Diego Trough accumulated a relatively
small amount of sediment owing to their small dimension and
by-passing of sediment to other basins.
In terms of unit rates (Table 2), all the offshore
basins pretty much have the same accumulation rate, which
indicates that those basins have been dominated by
comparable hemipelagic sedimentation. The nearshore
basins, except San Diego Trough, evidently have higher
accumulation rates, especially in Recent time.
Considering the changes of accumulation rates through
time, it is interesting to note that the offshore basins
generally exhibit a decreasing trend, whereas the nearshore
basins show an increasing trend. The decline of sediment
accumulation in the offshore basins probably resulted from
the continual subsidence of the Borderland area which
reduced the insular source area for the sediment. The
increase of sediment accumulation in the nearshore basins
is mostly likely attributed to the influx of terrestrial
141
sediment after the Ventura and Los Angeles Basins have been
filled up.
In summary, the depositional systems of the continental
Borderland are characterized by isolated marginal basin
sedimentation. In the offshore basins, such as Patton,
Tanner, Santa Cruz, and San Nicolas, the sediments are
mainly derived from the neighboring insular sources.
Fine-grained mass-fiow deposits and hemipelagics are
believed to dominate the basin-fill sequences. Catalina
Basin is a transitional type of basin between the offshore
and nearshore basins. It is filled with fine-grained
turbiditic and hemipelagic deposits similar to the offshore
basins but receives the sediments from the continent as
overflow from the nearshore basins. The nearshore basins,
including Santa Barbara, Santa Monica, and San Pedro Basins
and San Diego Trough, are filled with thick sequences of
continent-derived sediments. Except for Santa Barbara
Basin, well-developed fan systems spread all over the
basins and stack turbiditic deposits one on another. In
addition to fine-grained turbiditic and hemipelagic
deposits, coarse-grained turbidites also become important
and may well dominate the basin-fill sequences.
142
Chapter VI
SYNTHESIS
6*1 TECTONIC EVOLUTION OF THE CALIFORNIA CONTINENTAL
BORDERLAND
One of the most intriguing geologic features about the
California Continental Borderland is the variegated nature
of Mesozoic to Paleogene stratigraphy. Based on the
distribution of Mesozoic to Paleogene sequences, the
Borderland and the associated coastal region can be
regarded as a pair of comparable belts. Each belt is made
up of an eastern zone characterized by thick Mesozoic to
Paleogene sedimentary sequences and a western zone
characterized by coeval Franciscan-type rocks. The
petrotectonic configuration of the parallel zones has led
some geologists to the belief that they are comparable to
the forearc basin sequence-trench complex doublet which is
characteristic of an active continental margin (Howell and
Vedder, 1981; Crouch,1979, 1981; Dickinson, 1981).
It may not be difficult to visualize the inner
Borderland belt as a part of the early Tertiary continental
margin. But why is a similar belt repeated in the
143
offshore area? Petrological studies of some of the
Mesozoic to Paleogene sequences exposed on the islands
indicated that these rocks owe their sources to a continent
to the east (Cole, 1977; Abbott and Smith, 1978; Abbott and
others, 1983; Bartlings and Abbott, 1983). This indicates
that the outer Borderland belt was located closer to the
continent in the early Tertiary and was later brought to
the present position by lateral Neogene tectonic movements.
As a matter of fact, the California continental margin
has been dominated by wrench tectonism for the last thirty
million years as a result of the collision between the East
Pacific Rise and the North American continental plate
(Atwater,1970). Large transcurrent movements have
transposed pieces of continental margin to the north and
stacked one on another. Backed with paleocurrent analysis
on Tertiary sequences, Howell and others(1974) claimed that
the outer Borderland was a sliver of continental margin
which was situated south of San Diego and was brought 300
Km to the north by the transcurrent movements. Later
sedimentological and paleomagnetic studies (Abbott and
others, 1983; Kamerling and Luyendike, 1979) further
supported this hypothesis and has led Crouch (1979) to
propose his tectonic model for the paired Borderland belts.
In spite of some other arguments (Yeats, 1976), the
transcurrent hypothesis seems fairly acceptable.
144
Eased on this study, the transposed-continentai-margin
model has been further validated. Although the Borderland
has been deformed by Neogene tectonism, the geographic
configuration of the paired Borderland belts still retains
a fairly intact picture. The geometry and provenance of
the Mesozoic to Paleogene sequences indicate that the outer
Borderland belt was situated south of San Diego as a part
of the active margin during Cretaceous to early Tertiary
time (Figure 41) .
At about 29 Ma, the East Pacific Rise started to impinge
on the continental margin (Atwater, 1970; Atwater and
Molnar,1973). As a result, wrench tectonism transplanted
the subduction along the continental margin as the Rivera
triple junction swept through (Dickinson, 1981). In early
Miocene, the transcurrent movements were concentrated along
the coastal region. A sliver of continental margin south
of San Diego was sliced from the continent and transposed
to the north-northwest by wrench activities. The sliver
moved offshore and north along a line located roughly along
the Santa Cruz-San Clemente Ridge to form the present outer
Borderland (Figure 42). Associated with wrench tectonism
were the widespread Miocene volcanism and uplift which
brought deep-seated rocks up to the surface to shed
coarse-grained detritus to form the San Onofre-type
145
Figure 41: Paleogeographic reconstruction of the southern
California continental margin at around 30 Ma.
146
/
#4
W
o
CO
147
Figure 42: Paleogeographic reconstruct ion of the sou
California continental margin at around 1
148
■ M If)
15Ma
149
deposits. Pull-apart activities also prevailed at this
time and were responsible for the initiation or deepening
of many southern California basins, such as Los Angeles,
Ventura, Ridge, Santa Cruz, San Nicolas,Patton and Tanner
(Figure 43) . These basins served as dump sites for the
neighboring highlands and have accumulated thick sequences
of Neogene sediments, especially those basins near the
cont inent.
At about 5 Ma, the major wrench activities jumped inland
to the present San Andreas Fault (Crowell, 1981). NW-SE
right-lateral transcurrent movements with NE-SW compression
became the dominant tectonic activities (Figure 44). In
the nothern part, associated with the bending of San
Andreas Fault, E-W trending compressional features with
left-lateral movements dominate Santa Barbara Basin, the
Northern Channel Islands, and other parts of the Transverse
Ranges. South of the Northern Channel Islands, the
Borderland yields to NW-SE to NNW-SSE trending en echelon
folds and faults which comply with the structural grain of
the Peninsula Ranges. Some of the present Borderland
basins, such as Santa Monica, Santa Barbara, San Pedro,and
Catalina, were formed at this time.
150
Figure 43: Schematic paleogeography of the California
Continental Borderland at around 15 Ma.
151
152
Figure 44: Paleogeographic reconstruction of the southern
California continental margin at around 2 Ma.
153
m z
154
6.2 FORMATION OF BORDERLAND BASINS
Coastal southern California is well known for its
numerous deep Tertiary basins in which thick sequences of
Neogene sediments are accumulated. The origin of these
basins is believed to be related to the transform tectonism
prevailing in the last 29 M.Y.. Tensional mechanisms in
consequence of complex wrench tectonism have been
exemplified and invoked to account for the formation of
many inland Neogene basins (Crowell, 1974a, 1974b, 1976).
However, it is not clear how the offshore basins were
formed, although similar kinds of mechanisms have been
suggested (Crowell, 1974b; Blake and others, 1978; Howell
and others,1980).
Based on this study, several interesting points about
the formation of Borderland basins have emerged. First of
all, the distribution of Pre-late Miocene sedimentary
sequences barely show any relationship to the present
Borderland basins (Figure 11). Only the late Miocene to
Recent deposits are affected by the present basin geometry.
This menifests that the Borderland basins did not begin to
take shape until late Miocene. Therefore, the formation of
Borderland basins can only be attributed to late Neogene
geologic events. Three diastrophic mechanisms, thermal
subsidence, compression, and wrench tectonism, that have
155
been prevailing in the Borderland since late Miocene are
believed to be responsible for the formation of Borderland
ba s i n s.
6.2.1 Thermal subsidence
As shown in the stratigraphic columns of the Borderland
basins (Figure 15), Zones B and D which are floored with
Franciscan-type basement are characterized by the absence
of a pre-Neogene sedimentary cover. Although a part of the
area is covered by Miocene sequences,erosional features are
very common in these deposits. This implies that most of
Zones B and D might have been subaeriaily exposed during
Miocene time. Sedimentary records preserved by the Miocene
San Onofre-type deposits also support the existence of
these highlands (Stuart, 1976; Platt, 1976; Vedder and
Howell, 1976b). Despite eustatic influences, it is fair to
say that a great part of Zones B and D was above or close
to sea level during the Miocene. But today most of these
areas are about 1000 m below sea level or even deeper. It
seems that an appreciable amount of subsidence has occurred
in these areas since the late Miocene. Interestingly
enough, the volcanic activities which prevailed in the
Borderland area during the early Miocene dwindled at around
10 Ma (Vedder and others, 1981). The coincidence of the
156
subsidence with the attenuation of magmatic activities in
these areas suggests that thermal decay of the crust might
be the causal effect for the subsidence and thus have
played an important role in basin development in the
Borderland area, especially in Zones B and D.
6.2.2 Compression
More prominent than thermal subsidence, compressional
factors also play a major role in basin formation. As
previously stated, the Borderland is largely made up of a
series of highs and lows. Although wrench activities have
some effects on the broad pattern, these basins and ridges
are essentially compressional features. Some of the
basins, such as Santa Barbara, Santa Cruz, and San Nicolas
Basins, are actually simple synclines in a broad sense
(Figures 2 and 11). For other basins, compressional
features may not appear as a direct factor in basin
formation, but they still delineate the broad outline for
the basins.
6.2.3 Wrench tectonism
Wrench tectonism is the most conspicuous mechanism that
dominates basin development in the Borderland. There are
three types of basin formation associated with wrench
tectonism:
157
1. Pull-apart
This is best exemplified by Patton and Tanner Basins.
As shown in Figures 45 and 14, both basins are bounded by
NW trending transcurrent faults on either side. The Patton
Fault Zone extends from the south into this area and
gradually dies out to the north. The Santa Rosa-Cortes
Fault Zone starts out on the northeastern side of Tanner
Basin and gradually picks up most of the transcurrent
movement to the north. The differential movements along
the two fault zones create a zone of extension between.
Instead of developing normal faults that are perpendicular
to the transcurrent faults as Crowell (1974b) suggested, a
series of nearly N-S trending faults take up the extension
to give way to low-angle normal faults. These faults are
responsible for the down dropping of the Patton-Tanner Low
and many other small basins on the Patton Ridge as well
(Figure 11).
Pull-apart mechanism was also invoked to account for
some of the small basins in Zone B, but the dimensions are
much reduced (Greene and others, 1979).
2.Transverse Blocking
This form of mechanism was first proposed by Luyendyke
and others (1980). Santa Monica and Catalina Basins are
formed mainly in this way. As shown in Figure 46, the
158
Figure 45: Pull-apart mechanism and associated structural
pattern in the Patton-Tanner Low. a. Schematic
drawing, b. Structural features. The dotted
bands are the Santa Rosa-Cortes and Patton
Fault Zones respectively.
159
160
Pull-apart
r i
\ \ 4
%
Figure 46: Transverse blocking and associated structural
features in the Santa Monica Belt. a. Late
Miocene, b. Present.
161
3
Newport-
Inglewood Fault
Santa Cruz-
San Clemente Fault
Transverse Ranges
Zone of
subsidence v
Santa Monica
Basin
b
Zone of
compression
Palos
Verdes
High
Northern Channel Islands and Santa Monica Mountains form a
barrier blocking the northwestward movement of the southern
Borderland. The Santa Monica belt which is the area
bounded by the Newport- Inglewood and Santa Cruz-San
Clemente Fault Zones is subjected to aifferntial stress as
a result of the blocking. Because the northeastern margin
of the Santa Monica belt has been locked up while the
northern Channel Islands continue to be pushed northward by
the outer Borderland, the northwestern corner of the belt
becomes an area subject to extension and subsidence. This
mechanism may account for the localization of the
depocenter at the northwest corner of the basin (Figure
47). This kind of phenomenon can also be observed in Los
Angeles, Santa Cruz, and San Nicolas Basins.
3. Sagging
In Zone B, a number of transcurrent faults bear a
NNW-SSE trend (Figure 14). However, relative movements of
the two blocks on either side of the fault do not -totally
follow the fault trace but show a slight divergence (Figure
48). The divergence is not significant enough to generate
prominent extentional features like detachment faults, but
causes both sides of the fault to tip down toward the
fault. As a result,the faults become the loci for the
basins. San Pedro Basin and San Diego Trough are actually
formed in this way (Figure 49).
163
Figure 47: Subsidence
structural
Piiocene,
of Santa Monica Basin as related to
features. a. Lower to middle
b. Upper Pliocene to Recent.
164
0 10Km
0 10Km
165
Figure 48: Schematic picture of sagging along the
transcurrent fault.
166
Fault trace
Zone of
subsidence
Block
movement
Plane View
Cross Section
Figure 49: Subsidence
structural
Piiocene,
of San Pedro Basin as related to
features. a. Lower ro middle
b. Upper Pliocene to Recent.
168
169
In summary, the present-day Borderland basins have been
formed during the late Neogene. Thermal deterioration of
the crust in consequence of the cessation of magmatic
activities induced the regional subsidence and provided the
basis for basin formation. Compression shaped the
large-scale features of the Borderland and outlined the
framework for the basins. Wrench tectonism exerted direct
influences on the localization of the depositional basins.
6.3 PALEOCEANOGRAPHIC EVENTS
The California Continental Borderland has been
tectonically very active for the last 29 M.Y.. Without
doubt, the Neogene sedimentation history of the Borderland
is dominated by tectonism. However, paleoceanographic
influences should not be overlooked. Paleoceanographic
effects may not be as dramatic as tectonic influences and
have diffferent dominant time scales, but they tend to
influence a large area at the same time. Therefore, by
looking through the sedimentary records, the imprints of
paleoceanographic effects should be recognizable in spite
of the tectonic influences. Since the Neogene records are
better preserved in the Borderland, only the Neogene
paleoceanographic events will be discussed.
170
6.3.1 Miocene event
The Miocene of coastal California is marked by the
widespread Monterey-type deposits (Pisciotto and Garrison,
1981). The geographic distribution and the dominance of
biogenic pelagic components of the Monterey Formation
indicate that the Miocene was an epoch of high sea stand
and intense biological productivities in coastal California
(Ingle, 1981). In the Borderland, the Miocene sequences
are also the most widely distributed. They often occur as
drape-like layers 'covering various topographic
irregularities, both basins and ridges (Figure 11). In
addition to volcaniclastic sediments, diatomaceous shales
comparable to the Monterey-type deposits dominate these
sequences. Especially on many of the ridges, Miocene
sequences very often are the only sedimentary cover. These
features support the point that the Miocene was an epoch of
high sea stand and high biogenic sedimentation in this
area.
In spite of the ubiquitousness of Miocene strata, the
Upper Miocene sequences are often separated from the Lower
Miocene sequences by a distinct unconformity (Figure 15).
This unconformity is widely found in Zones B and D where it
often shows up as an angular discordance. Even in Zone C
where the Miocene strata are mostly a continuous sequence,
171
different facies patterns between the upper and lower
Miocene sequences can be perceived in terms of reflection
characteristics. Since Zones B and D are mostly above or
close to sea level during Miocene time, the depositional
hiatus represented by the unconformity is very likely
attributable to a period of sea level fall. Although good
geochronological data are not available, the youngest rock
beneath the unconformity was dated to be 13.2 Ma on the
Patton Ridge (Crouch, 1981). In other areas,crude
paleontologic data manifest that the" unconformity is
approximately equivalent to late Luisian to early Mohnian
in age which is about 15 to 13 Ma.
6.3.2 Mio-Pliocene event
The Miocene to Pliocene transition is another important
paleoceanographic event in the Borderland. As stated
above, the Miocene is characterized by biogenic pelagic
sedimentation which commonly laid down drape-like sequences
blanketing all the topographic irregularities. The
Pliocene to Recent deposits, instead, occur as flat-lying
sequences filling in the lows of the topography (Figure
11). The transition from Miocene biogenic pelagic
sedimentation to Pliocene-to-Recent epiclastic
sedimentation indicates that significant paleoceanographic
changes took place at the Mio-Pliocene transition so that
the Miocene biogenic sedimentation ceased and was replaced
by mass-flow deposition. This transition can be observed
in every Borderland basin and a similar transition has been
described in one land section at nearby Newport Bay (Ingle,
1973; Teng, 1984). It seems that this transition is a
widespread event in the Southern California Borderland
area. Preliminary studies suggest that this event resulted
from the paleoceanographic changes associated with the sea
level fall at about 4.5 Ma (Barron, 1976; Teng, 1984).
However the details of this even: still remain to be
studied.
6.3.3 Pliocene event
During Pliocene to Recent time, the Borderland has been
characterized by fairly continuous mass-flow sedimentation.
Within the basin-fill sequences, a distinct boundary often
can be recognized between the lower and upper basin-fill
deposits (PI and P2 in the last chapter). This boundary
sometimes shows up as discordant surfaces near the fringe
of the basins. It seems that this boundary represents a
period of slow or non-deposition so that the tectonic
activities were able to deform the lower basin-fill
sequences to an appreciable extent before the upper
173
basin-fill sequences began to be deposited. Since the
mass-flow deposits are believed to be laid down mainly
during the low sea stand (Nardin, 1981), this boundary may
well represent a period of high sea stand, during which the
epiclastic sediments were mainly trapped on the shelf or in
the coastal zone and could not reach the deep basins.
Although no good biostratigraphic data can be used to pin
down the time of this boundary, crude age approximations
based on sedimentation rate and dredge sample fossil data
point to the upper Pliocene (3 to 2 Ma) for the age of the
boundary.
Comparing the Neogene paleoceanographic changes in the
Borderland with coeval global eustatic fluctuations (Vail
and Hardenbol,197S), it is interesting to note that they
are harmoniously consistent with each other (Figure 50).
According to Vail's curve, the Miocene is, by and large, a
period of high sea stand with a sharp drop at about 14 Ma.
The Mio-Pliocene boundary is marked by two prominent
eustatic falls at around 6.2 Ma and 4.2 Ma. A high sea
stand is centered around 2.5-2.8 Ma. These major eustatic
changes match with the paleoceanographic variations
inferred from this study rather well, especially when
taking into account the uncertainties on the reponse of
coastal onlap/offlap to sea level changes and the available
174
Figure 50: Neogene paleoceanographic fluctuations and
stratigraphic evolution in Tanner and other
Borderland Basins.
(sea
sense
level fluctuations are drawn in a relative
, modified from Vail and Hardenbol, 1979)
175
Tanner
/ .2
:x
( 0
< D
/ ^
( d >
\ ^
\ d >
X * «
. — . -
x - - -
Rising Falling
Sea level curve
A
a)
g
‘c
0)
CD
o
in
0 Ma
2.5 Ma
4.5 Ma
14 Ma
20 Ma?
o
c n
(A
c d
geochronologic data. Other stratigraphic and paleontologic
studies on the coastal California and other parts of the
world also support the validity of the general picture of
these Neogene paleoceanographic changes (Ingle, 1980; Savin
and others, 1981).
Based on the seismic stratigraphies and available
geologic information, the gross picture of the Neogene
paleoceanographic changes of the Borderland basins can be
depicted on the order of several million years. Events of
smaller orders can also be recognized on the seismograms,
but without core data, these events cannot be discretely
defined in time. This is a question worth further
explorat ion.
177
Chapter VII
CONCLUSIONS
The collection of seismic reflection data in the last
two decades has reached a level where the time is ripe for
an overall seismic stratigraphic analysis of the California
Continental Borderland. A whole gamut of reflection
seismograms, including 6 to 9 sec deep-penetration, 2 to 4
sec intermediate-penetration, and 0.25 to 1 sec
shallow-penetration profiles, have been obtained from the
oil industry, US Geological Survey, and USC marine geology
laboratory to provide the database for this study.
Depending on the characteristics of the seismograms,
different reflection profiles have different applications,
in which deep-penetration profiles are used to build up the
structural framework and stratigraphic sequences of the
study area, deep- and intermediate-penetration profiles to
delineate small structures, and shallow-penetration
profiles to help designate the sequences as well as facies
of the basin sediments.
In general, seismic stratigraphic interpretation
includes four basic steps; structural, sequence, facies,
173
and geohistory analyses. Structural analysis involves
delineating the geometric features of reflection surfaces
and is often fraught with pitfalls. Sequence analysis is
basically a stratigraphic analysis for seismograms, to
which most of the standard stratigraphic principles apply.
Facies analysis is the litholcgic interpretation of the
depositional sequences in which the concepts of
depositional systems are heavily invoked. Geohistory
analysis is an integrated analysis that synthesizes the
information obtained from the reflection profiles and
regional- geology. The approach used in this study largely
follows these steps.
The Borderland and associated coastal area can be
divided into two subparallel belts based on the
distribution of pre-Neogene rocks. Each belt is made up of
an eastern zone characterized by a thick Mesozoic to
Paleogene sedimentary sequence and a western zone
characterized by the coeval melange deposits. The couplet
of the pre-Neogene rocks resembles the coupling of the
Great Valley Sequence and Franciscan complex that
characterized the California continental margin in early
Tertiary time. The outer Borderland belt can be regarded
as a sliver of continental margin that has been transposed
to its present position by late Cenozoic tectonic
activities.
179
Most of the structural features in the present
Borderland are attributed to Neogene tectonism. The
northern structural terrain which includes Santa Barbara
Basin and the northern Channel Islands is characterized by
E-W structural features that are affiliated with the
structural grain of the Transverse Ranges. The southern
terrain which comprises the rest of the Borderland is
characterized by NW-SE structural features that are
consistent with the structural grain of the Peninsular
Ranges. For the first-order structures, the northern
terrain is an anticlinorium-synclinorium couple, whereas
the southern terrain can be divided into a series of
structural highs and lows aligned in NNW-SSE direction in
en echelon fashion. For the second order structures, E-W
trending compressional features dominate the eastern and
central part of the northern terrain and gradually die out
to the west where the NW-SE trending structures become
dominant. The second-order structures of the southern
terrain vary with the basement geology and the first-order
structures. NW-SE trending transcurrent faults and
associated N-S trending normal faults dominate Zone D and
the western half of Zone B, whereas NW-SE trending
compressional features dominate Zone C and the eastern half
of Zone B. The structural patterns suggest that N-S
180
compression with left-lateral shear is the major tectonic
stress in the northern terrain, and NW-SE right-lateral
shear with NE-SW compression is the major tectonic stress
in the southern terrain.
Stratigraphically many of the Borderland basins share
comparable characteristics in spite of the differences in
sediment thickness. In Zone D, Patton and Tanner Basins
are floored with Franciscan-type basement draped by Miocene
sequences and filled with Miocene to Recent deposits. In
Zone C, Santa Cruz, San Nicolas, and probably Santa Barbara
Basins are floored with a thick Mesozoic to Paleogene
sequence draped by Miocene layers and filled with Pliocene
to Recent sediments. In Zone B, Santa Monica and San Pedro
Basins are floored with Franciscan-type basement draped by
Miocene sequences and filled with thick Pliocene to Recent
deposits. Catalina Basin and San Diego Trough are also
based on Franciscan-type deposits, but they are filled with
Miocene to Recent sediments. As inferred from the outcrop
and core sample studies, the Mesozoic to Paleogene
sequences in Zone C are composed of shallow to deep water
clastic deposits. The coeval Franciscan-type basement is
made up of melange deposits. The Miocene sequences are
mainly diatomaceous shales, volcaniclastics, and mass-flow
deposits. The Pliocene to Recent sequences are mainly
mass-flow deposits and hemipelagics.
181
The present Borderland basins did not begin to take
shape until late Miocene. Genuine basin-fill deposits
whose distribution is confined to the basins are the
'Pliocene to Recent sequences. Depositional systems of the
Borderland basins are characterized by isolated marginal
basin sedimentation. For the offshore basins, such as
Patton, Tanner, Santa Cruz, and San Nicolas, fine-grained
mass-flow deposits and hemipelagics derived from thei
neighboring insular sources dominate the basin-fill
sequences. Catalina Basin is a transitional zone between
the offshore and nearshore basins, in which fine-grained
turbiditic deposits and hemipelagics derived from both
insular sources and the continent have been deposited. For
the nearshore basins, including Santa Barbara, Santa
Monica, San Pedro basins, and San Diego Trough, a huge
amount of continent-derived sediment has often been dumped
into the depressions as prominent deep-sea fans spreading
over the entire basin. Coarse-grained mass-flow deposits
may be the dominant facies in the basin-fill sequences
instead of the fine-grained turbidites and hemipelagics.
Based on the geologic information obtained from this and
other studies, the geologic evolution of California
Continental Borderland can be depicted. During the
Mesozoic to early Paleogene, the southern California
182
coastal area was a part of the active margin and
characterized by the couplet of a coherent forearc
sedimentary sequence and a coeval trench melange deposit.
At about 29 Ma, the East Pacific Rise collided with the
North American Continent and began to transform subduction
activities to wrench tectonics. As the Rivera triple
junction swept through the area, subduction ceased and was
transplanted by transform activities. The transcurrent
movements were concentrated along the coastline in early
Miocene and transposed a sliver of continental margin
situated south of San Diego northward to offshore
California to form the present outer Borderland.
Associated with the wrench tectonism, magmatic activities
and diastrophic movements spread over the Borderland and
caused drastic subsidence and uplift in this area. At
about 5 Ma, the major transcurrent movements jumped inland
to the present San Andreas Fault. The wrench tectonics
dwindled in the Borderland and in many places have been
overwhelmed by the compressional activities associated with
the uplift of the Transverse Ranges. The present
configuration of the Borderland has been forged mainly in
this period.
The origin of Borderland basins cannot be attributed to
wrench tectonics alone as used to be thought. Thermal
183
subsidence as a result of cessation of magmatic activities
in the Miocene provided the basis for basin formation.
Compression shaped the broad highs-and-lows configuration
of the present Borderland and outlined the framework for
the basins. Wrench tectonism determined the loci of the
basins by means of pull-apart, transverse blocking, and
sagging.
Based on the stratigraphic characteristics of the
Borderland basins, three major paleoceanographic events can
be inferred. The widespread occurrence of Miocene
biogenic pelagic sequences indicates that the Miocene was a
period of high sea stand and high bioproductivitv in
southern California. The unconformity often present with
the Miocene sequences is believed to represent the sea
level fall at about 14 Ma. The abrupt change of Miocene
biogenic pelagic sedimentation to Pliocene mass-fiow
deposition is attributed to the paleoceanographic changes
associated with the sea level fall at about the
Mio-Pliocene boundary (about 4.5 Ma, and possibly 6.2 Ma).
The distinct boundary between the old and young basin-fill
sequences is thought to reflect a period of slow
sedimentation in consequence of the sea level rise at about
2.8 Ma. These paleoceanographic changes are consistent
with the global eustatic fluctuations and with other
184
H-
paleoceanographic studies in southern California and other
areas of the world.
185
REFERENCES
Abbott, P. L., and Smith, T. E., 1978, Trace-eiement
comparison of clasts in Eocene conglomerate,
southwestern California and northwestern Mexico: Jour.
Geology, v.86, p.753-762.
Abbott, P. L., and others, 1983, A tectonic slice of Eocene
strata, northern part of California continental
Borderland: in Larue, Q. K., and Steel, R. J., eds.,
Cenozoic marine sedimentation, Pacific Margin, USA.
Pacific Section, SEPM, p.151-168.
Addy, S. K., and Buffler, R. T., 1984, Seismic stratigraphy
of shelf and slope, northern Gulf of Mexico: AAPG
Bull., v.68, p.1782-1789.
Atwater, T., 1970, Implications of plate tectonics for the
Cenozoic tectonic evolution of western North America:
Geol. Soc. Amer. Bull., v.81, p.3515-3536.
Atwater, T., and Molnar, P., 1973 Relative motion of the
Pacific and North American plates deduced from sea-floor
spreading in the Atlantic, Indian, and south Pacific
oceans: Stanford Univ. Pubs. Geol. Sci., v.13,
p.136-148.
Bally, A. W., ed., 1983a, Seismic expression of Structural
styles - Vol.l: AAPG, 216p.
, 1983b, Seismic expression of structural styles -
Vol. 2: AAPG, 327p.
— ----, 1983c, Seismic expression of structural styles -
Vol. 3: AAPG, 448p.
Barron, J. A., 1976, Revised Miocene and Pliocene diatom
biostratigraphy of Upper Newport Bay, Newport Beach,
California: Marine Micropaleontology, v.l, p.27-63.
186
Bartling, W. A., and Abbott, P. L., 1983, Upper Cretaceous
sedimentation and tectonics with reference to Eocene,
San Miguel Island, and San Diego Area, California: in
Larue, D. K., and Steel, R. J., eds., Cenozoic marine
sedimentation, Pacific Margin, USA. Pacific Section,
SEPM, p.133-150.
Blake, M. C., and others, 1978, Neogene basin formation in
relation to plate-tectonic evolution of San Andreas
fault system, California: AAPG Bull., v.62, p.344-372.
Bottjer, D. J., and Link, M. , 1984, A synthesis of late
Cretaceous southern California and northern Baja
California paleogeography: in Crouch, J. K, and
Bachman, S. B. eds., Tectonics and Sedimentation along
the California margin: Pacific Section, SEPM, p.171-188
Brown, L. F., and Fisher, W.L., 1977, Seismic stratigraphic
interpretation of depcsitional systems: Examples from
Brazilian rift and pull-apart basins: in Payton, C. E.,
ed., Seismic Stratigraphy - applications to hydrocarbon
exploration. AAPG Mem. 26, p.213-248.
, 1980, Seismic stratigraphic interpretation and
petroleum exploration: Tulsa, AAPG Continuing Education
Course Notes Series no.16.
Campbell, I., 1962, Geologic Map of California: San Diego-
E1 Centro Sheet: California Division of Mines and
Geology.
, 1966, Geologic Map of California: Santa Ana Sheet:
California Division of Mines and Geology.
Cole, M. R., 1977, Eocene paleocurrents and sedimentation,
San Nicolas Island, California: AAPG Bull., v.61,
p.237-247.
Conrad, C. L., and Ehlig, P. L,, 1983, The Monterey
Formation of the Palos Verdes Peninsula, California - An
example of sedimentation in a tectonicallv active basin
within the California Continental Borderland: in Larue,
D. K., and Steel, R. J., eds., Cenozoic marine
sedimentation, Pacific Margin, USA. Pacific Section,
SEPM, p.103-116.
Cook, H. E., ed., 1979, Geologic studies of the Point
Conception deep stratigraphic test well OCS-CAL 78-164
no.l, outer continental shelf, southern California: U.S.
Geol. Surv. Open-file Report, 79-1218, 148p..
187
Crouch, J. K., 1979, Neogene tectonic evolution of the
California Borderland and western Transverse Ranges:
GSA Bull., v .90, p.338-345.
, 1981, Northwest margin of the California Continental
Borderland: marine geology and tectonic evolution: AAPG
Bull., v.65, p.191-218.
, Bachman, S. B., and Shay, J. T., 1984, Post-Miocene
compressional tectonics along the central California
margin: in Crouch, J. K., and Bachman, S. B., eds.,
Tectonics and Sedimentation along the California margin:
Pacific Section, SEPM, p.37-54.
Crowell, J. C., 1974a, Sedimentation along the San Andreas
fault, California: in Dott, R. H., Jr., and Shaver, R.
H., eds., Modern and Ancient Geosynclinal Sedimentation:
SEPM Spec. Pub., no.19, p.292-303.
, 1974b, Origin of late Cenozoic basins in southern
California: in Dickinson, W.R. ed., Tectonics and
Sedimentation: SEPM Spec. Pub., no.22, p.190-204.
, 1976, Implication of crustal stretching and
shortening of coastal Ventura basin, California: in
Howell, D.G., ed., Aspects of the Geologic History of
the California Continental 3orderland: AAPG Misc. Pub.,
24, p.365-382.
, 1981, An outline of the tectonic history of
southeastern California: in Ernst, W.G., ed., The
Geotectonic Development of California, Prentice-Hali,
p.583-600.
Dickinson, W. R., 1981, Plate tectonics and the continental
margin of California: in Ernst, W. G., ed., The
Geotectonic Development of California: Prentice-Hail,
p. 1-28.
, and Snyder, W. S., 1979, Geometry of triple
junctions related to San Andreas transform: Jour.
Geophys. Res., v.84, p.561-572.
Dobrin, M. B., 1976, Introduction to Geophysical
Prospecting: McGraw-Hill, 630p.
188
Doerner, D. P., 1969, Lower Tertiary biostratigraphv of
southwestern Santa Cruz Island: in Weaver, D. W., ed.,
Geology of the northern Channel Islands, southern
California Borderland: Los Angeles, California: Pacific
Section, AAPG and SEPM, p.17-29.
Domenico, S. N., 1974, Effect of water saturation on
seismic reflectivity of sand reservoirs encased in
shale: Geophysics, v.39, p.759-769.
Douglas, R. G., 1981, Paleoecology of continental margin
basins: A modern case history form the borderland of
southern California: in Douglas, R. G., and others,
eds.'^ Depositional Systems of Active Continental Margin
Basiiis: Short Course Notes, Pacific Section, SEPM,
p.121-156.
Drake, D. E., Kolpack, R. L., and Fischer, P. J., 1972,
Sediment transport on the Santa Barbara-Oxnard Shelf,
Santa Barbara Channel California: in Swift, D. J. P.,
and others, eds., Shelf Sediment Transport: Hutchinson
and Ross, p.307-332.
Emery, K. 0., 1960, The Sea off Southern California: John
Wiley and Sons, 366p.
Field, M., and Edwards, B. D., 1980, Slopes of the southern
California Continental Borderland: A.region of mass
transport: Pacific Section SEPM, Pacific Coast
Paleoaeography Symposium 4, p.169-184.
Gastil, R. G., Phillips, R. P., and Allison, E. C., 1975,
Reconnaissance geology of the state of Baja California:
GSA Memoir 140, 170p.
Gorsline, D. S.,* 1980, Deep water sedimentologic conditions
and models: Marine Geology, v.38, p.1-21.
, 1981, Fine sediment transport and deposition in
active margin basins: in Douglas, R. G., and others,
eds., Depositional Systems of Active Continental Margin
Basins, short course, Pacific Section, SEPM, p.39-59.
, Drake, D. E., and Barnes, P. W., 1968, Holocene
sedimentation in Tanner Basin, California Continental
Borderland: GSA Bull., v.79, p.659-674.
189
Greene, H. G., and others, 1979, Implications of fault
patterns of the inner California Continental Borderland
between San Pedro and San Diego: in Abbott, P. L., and
Elliot, W. J., eds., Earthquakes and other perils: San
Diego region: GSA Annual Meeting Guidebook, p.29-46.
Hill, D. J., 1976, Geology of the Jurassic basement rocks,
Santa Cruz Island, California and correlation with other
Mesozoic basement terranes in California: in Howell,
D.G., ed., Aspects of the Geologic History of the
California Continental Borderland: AAPG Misc. Pub., 24,
p. 16-46.
Howell, D.G., ed., 1976a, Aspects of the Geologic History
of the California Continental Borderland: AAPG Misc.
Pub., 24, 561p.
, 1976b, Inferred Eocene and Miocene cross sections of
the southern California Borderland: in Howell, D.G.,
ed., Aspects of the Geologic History of the California
Continental Borderland: AAPG Misc. Pub., 24, p.363-364.
, and others, 1974, Possible strike-slip faulting in
the southern California Borderland: Geology, v.2,
p.93-98.
, and Link, M. H., 1979, Eocene conglomerate
sedimentology and basin analysis, San Diego and the
southern California Borderland: Jour. Sed. Petrol.,
v.49, p.517-540.
-------, and others, 1980, Basin development along the late
Mesozoic and Cenozoic California margin: a plate-
tectonic margin of subduction, oblique subduction and
transform tectonics: Int. Assoc. Sediment., Spec. Pub.
4, p.43-62.
, and Vedaer, J., 1981, Structural implications of
stratigraphic discontinuities across the southern
California Borderland: in Ernst, W. G., ed., The
Geotectonic Development of California, Prentice-Hall,
p.535-558.
, and Vedder, J. G., 1983 Ferrelo Fan, California:
Depositional system influenced by eustatic sea level
changes: Geo-Marine Letters, v.3, p.187-192.
Ingle, J. C., Jr., 1966, The Movement of Beach Sand:
Elsevier, 221p.
190
, 1973, Biostratigraphy and paleoecology of early
Miocene through early Pleistocene benthic and planktonic
formainifera, San Joaquin Hills -Newport Bay-Dana Point
area, Orange County, California: SEPM Trip 1 Guidebook,
Miocene sedimentary environments and biofacies,
southeastern Los Angeles Basin. p.18-38.
, 1980, Cenozoic paleobathymetry and depositional
history of selected sequences within the southern
California continental borderland. Cushman Found.
Foram. Res., Spec. Pub., 19, p.163-195.
, 1981, Origin of Neogene diatomites around the north
Pacific Pacific rim: in Garrison, R. E., and others,
eds., The Monterey Formation and related siliceous rocks
of California: Pacific Section, SEPM, p.159-179.
Junger, A., 1979, Maps and seismic profiles showing
geologic structure of the northern Channel Islands
Platform, California Continental Borderland: U. S.
Geol. Surv. Misc. Field Studies Map MF-991.
, and Wagner, H. C., 1977, Geology of the Santa Monica
and San Pedro Basins, California Continental Borderland:
U. S. Geological Survey Map, MF-320, 10p..
Kamerling, M. J., and Luyendyk, B. P., 1979, Tectonic
rotation of the Santa Monica Mountains region, western
Transverse Ranges, California, suggested by
paleomagnetic vestors: GSA Bull., v. 90, p.331-337.
Karig, D. E., Peterson, M. N. A., and Shor, G. G., Jr.,
1970, Sediment-capped guyots in the Mid-Pacific
Mountains: Deep-Sea Res., 17, p.373-378.
Kolia, V. , Buffler, R. T., and Ladd, J. w., 1984, Seismic
stratigraphy and sedimentation of Magdalena Fan,
southern Colombian Basin, Caribbean sea: AAPG Bull.,
v.68, p.316-332.
Legg, M. R., and Kennedy, M. P., 1979, Faulting offshore
San Diego and northern Baja California: in Abbott, P.
L., and Elliot, W. J., eds., Earthquakes and other
perils: San Diego region: GSA Annual Meeting guidebook,
p.29-46.
Link, M.H., Squires, R. L., and Colburn, I. P., 1984, Slope
and deep-sea fan facies and paleogeography of upper
Cretaceous Chatsworth Formation, Simi Hills, California:
AAPG Bull., v.68, p.850-873.
191
Luyendyk, B. P., and others, 1980, Geometric model for
Neogene crustal rotations.in southern California: GSA
Bull., v.91, p.211-217.
McLean, H., Howell, P.G., and Vedder, J.G., 1976, Miocene
strata of Santa Cruz and Santa Rosa Islands, a
reflection of tectonic events in the southern California
Borderland: in Howell, D.G., ed., Aspects of the
Geologic History of the California Continental
Borderland: AAPG Misc. Pub., 24, p.80-106.
McLean, H., and Howell, D. G., 1983, Miocene Blanca Fan,
Northern Channel Islands, California: small fans
reflecting tectonism and volcanism: Geo-Marine Letters,
v .3, p.161-166.
Middleton, M.F., 1984, Seismic geohistory analysis - a case
history from the Canning Basin, Western Australia:
Geophysics 49, p.333-343.
Mitchum, R. M., Jr., 1978, Seismic stratigrpahic
investigation of west Florida slope, Gulf of Mexico: in
Framework, Facies and Oil-trapping Characteristics of
uuper continental margin: AAPG Studies in Geology 7,
p.193-223.
, Vail, P. R., and Thompson, S., 1977a, Seismic
stratigraphy and global changes of sea level, part 2,
The depositional sequence as a basic unit for
stratigraphic analysis: in Payton, C. E., ed., Seismic
Stratigraphy - applications to hydrocarbon exploration.
AAPG Mem 26, p.53-62.
,Vail, P.R., and Sangree, J. B., 1977b, Seismic
stratigraphy and global changes of sea level, part 6,
Stratigraphic interpretation of seismic reflection
patterns in depositional sequences: in Payton, C. E.,
ed., Seismic Stratigraphy - applications to hydrocarbon
exploration. AAPG Mem 26, p.117-134.
Moore, D. G., 1969, Reflection profiling studies of the
California Continental Borderland - structure and
Quarternary turbidite basin: GSA Spec. Paper 107, 142p.
Nardin, T. R., 1981, Seismic stratigraphy of Santa Monica
and San Pedro Basins, California Continental Borderland:
late Neogene History of Sedimentation and Tectonics:
unpub. PhD dissertation, Univ. Southern California, Los
Angeles, 295p.
192
, 1983, Late Quarternary depositional systems and sea
level change, Santa Monica and San Pedro Basins,
California Continental Borderland: AAPG Bull., v.67,
p.1104-1124.
, and others, 1979a, A review of mass movement
processes, sediment and acoustic characteristics, and
contrasts in slope and base-of-slope systems versus
canyon-fan-basin floor systems: in Geology of
Continental Slopes: SEPM Spec. Pub., no.27, p.61-73.
, Edwards, B. D., and Gorsline, D. S., 1979b, Santa
Cruz Basin, California borderland: dominance of slope
processes in basin sedimentation, in Geology of
Continental Slopes: SEPM Spec. Pub., no.27, p.209-221.
Neidell, N. S., and Poggiagliolmi, E., 1977, Stratigraphic
modelling and interpretation - Geophysical principles
and techniques, in Payton, C. E., ed., Seismic
Stratigraphy - applications to hydrocarbon exploration.
AAPG Mem 26, p.389-416.
Normark, W. R., and Hess, G. R., 1979, Distributary
channels, sand lobes, and mesotopography of Navy
submarine fan, California borderland, with applications
to ancient fan sediments: Sedimentology, v.26,
p.747-774.
Normark, W. R., Mutti, E., and Bouma, A. H., 1983, Problems
in turbidite reseach: a need for COMFAN: Geo-Marine
Letters, v.3, p.53-56.
Paul, R. C., and others, 1976, Geological and operational
summary, southern California deep stratigraphic test
well OCS-CAL 75-70 no.i, Cortes Bank area offshore
California: U.S. Geol. Surv. Open-file Report 76-232,
65p.
Payton, C. E., ed., 1977, Seismic Stratigraphy -
applications to hydrocarbon exploration. AAPG Mem 26,
516p.
Pisciotto, K. A., and Garrison, R. E., 1981, Lithofacies
and depositional environments of the Monterey Formation,
California: in Garrison, R. E., and others, eds., The
Monterey Formation and related siliceous rocks of
California: Pacific Section, SEPM, p.97-122.
193
Platt, J. P., 1976, The significance of the Catalina Schist
in the history of southern California Borderland: in
Howell, D.G., ed., Aspects of the Geologic History of
the California Continental Borderland: AAPG Misc. Pub.,
24, p.47-52.
Reynolds, S., 1984, Late Cenozoic sedimentation,
stratigraphy, structure and tectonic history, San
Nicolas and Tanner Basins, California Continental
Borderland: unpub. MS thesis, Univ. Southern Calif.,
224p.
Rupke, N. A., 1978, Deep clastic seas: in Reading, H. G.,
ed., Sedimentary Environment and Facies: Elsevier,
p.372-415.
Sangree, J. B., and Widmier, J. M., 1977, Seismic
stratigraphy and global changes of sea level, part 9:
Seismic interpretation of clastic depositional facies:
in Payton, C. E., ed., Seismic Stratigraphy -
applications to hydrocarbon exploration. AAPG Mem 26,
p.165-184.
Schwalbach, J. R., 1982, A sediment budget for the northern
region of the California Continental Borderland: unpub.
MS thesis, Univ. Southern Calif., 212p.
Shepard, F. P., and Emery, K. 0., 1941, Submarine
topography off the California coast - canyons and
tectonic interpretation: GSA Spec. Paper 31, 171p.
Shepard, F. P., and Marshall, M. N., 1973, Currents along
floors of submarine canyons; AAPG Bull., v.57,
p.244-264.
Shor, G. G. Jr., and Raitt, R. W., 1958, Seismic studies in
the southern California Borderland: Section 9(2) -
Geofisica aplicada, Intern. Geol. Congr., 20th, Mexico,
p.243-259.
Sheriff, R. E., 1980, Seismic Stratigraphy: International
Human Resources Development Corp.
, 1932, Structural interpretation of seismic data:
AAPG Education course Note Series no.23, 73p.
, and Geldart, L. P., Exploration Seismology, Volume 2
- Data Processing and Interpretation: Cambridge,
London, 221p.
194
Stuart, C., 1976, Source terrain of the San Onofre Breccia
preliminary notes: in Howell, D.G., ed., Aspects of the
Geologic History of the California Continental
Borderland: AAPG Misc. Pub., 24, p.309-325.
Stuart, C. J., and Caughey, C. A., 1977, Seismic facies and
sedimentology of terrigenous Pleistocene deposits in
Northwest and central Gulf of Mexico: in Payton, C. E.,
ed., Seismic Stratigraphy - applications to hydrocarbon
exploration. AAPG Mem 26, p.249-276.
Savin, S. M., and others, 1981, Miocene benthic
foraminifera isotope record: A synthesis: Marine
Paleontology, v.6, p.423-450.
Teng, L . S., 1984, Depositional environments of late
Neogene rocks in Newport Lagoon area, southern
California: SEPM 1st Annual Midyear Meeting
(Abstracts), p.81.
Thornton, S. E., 1981, Holocene stratigraphy and
sediemntary processes in Santa Barbara Basin: Influence
of tectonics, ocean circulation, climate, and mass
movement: unpub.- PhD dissertation: Univ. Southern Calif.
351p.
Trosper, E. J., 1983, Classification of southern California
3orderland geomorphic features: unpubl. Geol. Report,
Univ. Southefrn Calif., Los Angeles, lOp..
Tucker, P. M., 1982, Pitfalls Revisited: SEG, Tulsa, 23p..
, and Yorston, H. J., 1973, Pitfalls in Seismic
Interpretation: SEG Monogr. Series no.2, Tulsa, 56p..
Vail, P. R., Mitchum, R. M., and Thompson, S., 1977a
Seismic stratigraphy and global changes of sea level,
part 2, Relative changes of sea level from coastal
onlap: in Payton, C. E., ed., Seismic Stratigraphy -
applications to hydrocarbon exploration. AAPG Mem 26,
p. 63-81.
, 1977b, Seismic stratigraphy and global changes of
sea level, part 4, Global cycles of relative changes of
sea level: in Payton, C. E., ed., Seismic Stratigraphy
- applications to hydrocarbon exploration. AAPG Mem 26,
p.83-98.
Vail, P. J., and Hardenbol, J., 1979, Sea-level changes
during the Tertiary: Oceanus, v.22, p.71-79.
195
Vedder, J. G., and Norris, R. M., 1963, Geology of San
Nicolas Island: U.S. Geol, Surv. Prof. Paper 369, 65p.
Vedder, J. G., and others, 1974, Preliminary report on the
geology of the Continental Borderland of southern
California: U.S. Geol. Surv. Open-File Report MF-624,
34p.
Vedder, J. G., and Toth, M. I., 1976a Proposed new
geographic names for features in the California
Continental Borderland: in Howell, D.G., ed., Aspects
of the Geologic History of the California Continental
Borderland: AAPG Misc. Pub., 24, p.12-14.
Vedder, J. G., and Howell, D. G., 1976a Neogene strata of
the southern group of Channel Islands, California: in
Howell, D.G., ed., Aspects of the Geologic History of
the California Continental Borderland: AAPG Misc. Pub.,
24, p.80-106.
Vedder, J. G., and Howell, D. G., 1976b Review of the
distribution and tectonic implications of Miocene debris
from the Catalina Schist, California Continental
Borderland and adjacent coastal areas: in Howell, D.G.,
ed., Aspects of the Geologic History of the California
Continental Borderland: AAPG Misc. Pub., 24, p.326-342.
Vedder, J. G., and others, 1979, Descriptions of dart core
samples R/V Samuel P. Lee Cruise L2-78-SC, May, 1978,
California Continental Borderland: U.S. Geol. Surv.
Open-File Report 79-936.
Vedder, J. G., and others, 1981a, Composition and
correlation of bedrock and sediment cores, R/V Sea
Sounder Cruise S3-79-SC, May 1979, California
Continental Borderland. U.S. Geol. Surv. Open-File
Report 81-744.
Vedder, J. G., Crouch, J. K., and Lee-Wong, F., 1981b,
Comparative study of rocks from Deep Sea Drilling
Project Holes 467, 468, and 469, and the southern
California Borderland: in Yeats and others, eds., Init.
Repts., DSDP, 63: Washington (U. S. Govt. Printing
Office), p.907-918.
Weaver, D.W., ed., 1969a, Geology of the northern Channel
Islands, southern California Borderland: Los Angeles,
California: Pacific Section, AAPG and SEPM, 200p.
156
, 1969b, Paleoceanographic implication and geologic
history: in Weaver, D. W., ed., Geology of the northern
Channel Islands, southern California Borderland: Los
Angeles, California: Pacific Section, AAPG and SEPM,
p.115-124.
, 1969c, The Creataceous rocks: in Weaver, D. W.,
ed., Geology of the northern Channel Islands, southern
California Borderland: Los Angeles, California: Pacific
Section, AAPG and SEPM, p.14-16.
, and Doerner, D. P., Lower Tertiary stratigraphy, San
Miguel and Santa Rosa Islands: in Weaver, D. W., ed.,
Geology of the northern Channel Islands, southern
California Borderland: Los Angeles, California: Pacif
Section, AAPG and SEPM, p.30-47.
Widess, M. B., 1973, How thin is a thin bed? Geoohvsics
38, p.1176-1180.
Woodford, A. 0., 1924, The Catalina metamorphic facies of
the Franciscan series: Univ. Calif. Dept, of Geol.,
Studies Bull., v.15, p.49-68.
Yeats, R. S., 1976, Extension verbsus strike-slip origin of
the southern California Borderland: in Howell, D.G.,
ed., Aspects of the Geologic History of the California
Continental Borderland: AAPG Misc. Pub., 24, p.455-485
, and others, 1981, Initial Reports, DSDP, 63,
Washington (U.S. Govt. Printing Office). 967p.
Yerkes, R. F., McCulloh, T. H., Schoellhamer, J. E., and
Vedder, J. G., 1965, Geology of the Los Angeles Basin,
California: U. S. Geol. Surv. Prof. Pap., 420-A, 57p.
197
-rH

Linked assets

University of Southern California Dissertations and Theses

Conceptually similar

PDF

Seismic sequence stratigraphy and structural development of the southern outer portion of the California Continental Borderland

PDF

A surface wave study of crustal and upper mantle structures of Eurasia

PDF

Stratigraphic and sedimentologic analysis of the Monterey Formation: Santa Maria and Pismo basins, California

PDF

Late Quaternary erosional and depositional history of Sierra del Mayor, Baja California, Mexico

PDF

The surface wave study of crustal and upper mantle structures of mainland China

PDF

Surface wave profiling for 3-D shear wave structure of the Pacific Ocean basin

PDF

Structure of Santa Cruz-Catalina Ridge and adjacent areas, Southern California Continental Borderland from reflection and magnetic profiling: Implications for late Cenozoic tectonics of Southern...

PDF

Seismic stratigraphy of Santa Monica and San Pedro Basins, California Continental Borderland: Late Neogene history of sedimentation and tectonics

PDF

Stable isotopes in live benthic foraminifera from the Southern California borderland

PDF

Deterministic and stochastic modelling of the high frequency seismic wave generation and propagation in the lithosphere

PDF

Animal-sediment relationships in dysaerobic bathyal environments: California continental borderland

PDF

Estuarine sediment transport and Holocene depositional history, Upper Chesapeake Bay, Maryland

PDF

Holocene stratigraphy and sedimentary processes in Santa Barbara Basin: Influence of tectonics, ocean circulation, climate and mass movement

PDF

A gravity and magnetic study of the Tehachapi Mountains, California

PDF

Geometry, kinematics, and a mechanical analysis of a strip of the Lewis allochthon from Peril Peak to Bison Mountain, Glacier National Park, Montana

PDF

Quaternary geomorphic surfaces on the northern Perris Block, Riverside County, California: Interrelationship of soils, vegetation, climate and tectonics

PDF

Late Cenozoic tectonics of the central Mojave Desert, California

PDF

Processes influencing transportation and deposition of sediment on the continental shelf, Southern California

PDF

Trends in extent and depth of bioturbation in Great Basin Precambrian-Ordovician strata, California, Nevada and Utah

PDF

Late Precambrian diabase intrusions in the southern Death Valley region, California: Their petrology, geochemistry, and tectonic significance

Asset Metadata

Creator Teng, Louis Sui-Yui (author)

Core Title Seismic stratigraphic study of the California Continental Borderland basins: Structure, stratigraphy, and sedimentation

Contributor Digitized by ProQuest (provenance)

Degree Doctor of Philosophy

Degree Program Geological Sciences

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

Tag geophysics,OAI-PMH Harvest

Language English

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c29-351356

Unique identifier UC11219066

Identifier DP28574.pdf (filename),usctheses-c29-351356 (legacy record id)

Legacy Identifier DP28574.pdf

Dmrecord 351356

Document Type Dissertation

Rights Teng, Louis Sui-Yui

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