A Thesis Submitted in Partial Satisfaction of the Requirements for the Degree of Master of Science In

Home , Kettleman Hills

CALIFORNIA STATE UNIVERSITY, NORTHRIDGE

DEPOSITIONAL ENVIRONMENTS OF THE

AVENAL SANDSTONE OF REEF RIDGE,

CENTRAL CALIFORNIA

A thesis submitted in partial satisfaction of the requirements for the degree of Master of Science in

Geology

Kristine Ann Kappeler

May, 1984 The Thesis of Kristine Ann Kappeler is approved:

L. Squires Committee Chairman

California State University, Northridge

ii DEDICATION

This thesis is dedicated to my family, whose encouragement, help, love, and moral support

allowed me to achieve this goal.

iii ACKNOWLEDGEMENTS

Special thanks go to the following property owners for allowing access to

the study area: John Den Hartog, Ed Kreyenhagen, Jerry and Leslie Sagasar, the

Avenal Gun Club, and Darrel Zwang. Without their generosity and cooperation this thesis could not have been undertaken. I am grateful to my father and Donald w. Frames, consulting geologists, for introducing me to the Avenal Sandstone of Reef Ridge, for accompanying me on numerous excursions, and for sharing their knowledge and expertise of the geology of the San Joaquin Valley area. I am further grateful to my mother and brother for assisting as field troopers on numerous occasions. I would like to thank my thesis chairman, Richard L. Squires, for all his help, support, encouragement, and guidance throughout the project, for identification of megafossils, and for critical review of this manuscript. I am appreciative of the help that A. Eugene Fritsche provided which led to interpretation of the depositional environments identified within this thesis, for petrographic assistance, and for review of this manuscript. I am grateful to LouElla R. Saul,

University of California, Los Angeles, who aided with documentation of megafossil identifications. Joyce R. Blueford, U. S. Geological Survey, and AI A.

Almgren, Union Oil Company, analyzed microfossil samples. S. Tony Reid,

Getty Oil Company, provided microfossil analysis by Green and Associates and subsurface data. Dave M. Advocate, Exxon Oil Company, assisted in the field and provided various photographs. Daniel A. Yamashiro, California State

University, Northridge, assisted with laboratory procedures. Gary Haunstein,

Getty Pipeline in Coalinga, aided with logistics.

iv I am especially indebted to Patricia A. Thall for typing the thesis and for her patience with my many revisions. Tony A. Furio, Linda Villareal, Basil Argyroudis, Karl Grundl, Gary Bedrossian, and Alain Bally, all of Getty Oil

Company, skillfully drafted the figures and tables.

v TABLE OF CONTENTS

Dedication ...... iii Acknowledgements iv List of lllustrations vii Tables .•••..•.•. ix Abstract X Introduction 1 Previous Work 10 Methods •••••••.•. 11 Age and Correlation 26 Geologic Setting 29 Structure •. 29 Stratigraphy 30 Lithosomes and Depositional Environments 33 Fluvial Lithosome ••••.•.•••.••••• 34 Fluvial Description 34 Fluvial Interpretation •• 38 Sand-Flat Tidal-Channel Deposits . 38 Tidal-Channel Conglomerate Description .••••••...•.•••••. 39 Tidal-Channel Sandstone-Fill Description 39 Sand-Flat Tidal-Channel Interpretation .•••. 44 Sand-Flat Lithosome •.••••• 45 Sand-Flat Description 45 Sand-Flat Interpretation 47 Upper Shoreface Lithosome 48 Upper Shoreface Description 48 Upper Shoreface Interpretation 49 Lower Shoreface Lithosome ••.••• 52 Lower Shoreface Description 52 Lower Shoreface Interpretation 54 Transgressive-Lag Lithosome 55 Transgressive-Lag Description 55 Transgressive-Lag Jnterpreta tion ••.•.. 56 Avenal-Kreyenhagen Unconformity 57 Provenance 59 Paleogeography 62 References •.••••••• 65 Appendix 1 74 Appendix 2 80 Appendix 3 82

vi LIST OF ILLUSTRATIONS

Figure Page

1. Index map of study area and vicinity showing major 2 physiographic features and surface exposures of the Avenal Sandstone.

2. Summation of names and age assignments of formations 3 on Reef Ridge.

3. Generalized geologic map of Reef Ridge showing areal 5 distribution of the Avenal Sandstone, major faults of the area, and megafossil localities.

4. Location of measured sections through the Avenal 6 Sandstone at Reef Ridge, Kings and Fresno Counties, California.

5. Location of oil fields and structures within the 7 vicinity of the study area.

6. Type E-log for Jacalitos oil field, H.C. Lillis No. 1 8 ~ec. 28, T21~ R16E).

7. Explanation for measured stratigraphic sections. 12

8. Stratigraphic section of the Avenal Sandstone measured 13 along the north side of Big Tar East, NEi of section 20, T23S, R17E, Garza Peak quadrangle, California.

9. Stratigraphic section of the Avenal Sandstone measured 14 along the south side of Garza Canyon, Ni of section 10, T23S, R16E, Garza Peak quadrangle, California.

10. Stratigraphic section of the Avenal Sandstone measured 15 along the south side of Canoas Canyon, SEi of section 32, T22S, R16E, the Dark Hole quadrangle, California.

11. Stratigraphic section of the Avenal Sandstone measured 16 along the south side of Reese Canyon, NEt of section 31, T22S, R16E, Garza Peak quadrangle, California.

12. Stratigraphic section of the Avenal Sandstone measured 17 along Arroyo Pinoso, NEt of section 35, T22S, R15E, Garza Peak quadrangle, California.

13. Stratigraphic section of the Avenal Sandstone measured 18 along the south side of Zapato Canyon, NEt of section 21, T22S, R15E, Kreyenhagen Hills quadrangle, California.

vii 14. Ternary diagrams showing composition of sandstones of 20 the Eocene Avenal Sandstone and Cretaceous Panoche Formation. 15. Correlation chart of various authors for comparison 27 of the age assignment of the Avenal Sandstone.

16. Fluviallithosome with interbedded lenses of conglom- 36 erate and sandstone exposured at the base of the Garza Canyon section.

17. Fluviallithosome with interbedded lenses of 36 conglomerate, sandstone, and shale rip-up clasts exposed at the base of the Garza Canyon section.

18. Scour-and-fill erosional contact of the tidal-channel 37 lag lithosome into parallel laminated sandstone of the tidal-channel sandstone-filllithosome exposed in Zapato Canyon.

19. Tidal-channel lag deposits range in thickness between 2 40 to 15 em thick interbedded with tidal-channel sandstone-fill deposits.

20. Bidirectional crossbedding of the tidal-channel 41 sandstone-filllithosome, pencil is 17 em long.

21. Crossbedding of the tidal-channel sandtone-filllithosome 41 preserved in concretions near the basal contact in Canoas Canyon.

22. Asymmetrical ripples of the tidal-channel sandstone-fill 42 lithosome exposed in Garza Canyon.

23. Climbing-ripple cross-lamination of the tidal-channel 43 sandstone-filllithosome exposed in Canoas Canyon. 24. Boxwork pattern of Ophiomorpha burrows characteristic 47 of the sandflat lithosome exposed in Zapato Canyon near the top of the section.

25. Bioturbated fine-grained sandstone of the upper 50 shoreface lithosome exposed in Canoas Canyon.

26. Paleogeography during deposition of the Avenal 63 Sandstone.

viii TABLES

Table

1. Petrology and field location of rock samples. 19

2. Heavy mineral analysis of five samples from the Avenal 21 Sandstone at Reef Ridge.

3. Composition of conglomerate samples from the Avenal 22 Sandstone at Reef Ridge.

4. Megafossils from the Avenal Sandstone, Reef Ridge, 24 Fresno and Kings Counties, California.

ix ABSTRACT

DEPOSITIONAL ENVIRONMENTS OF THE AVENAL SANDSTONE

OF REEF RIDGE, CENTRAL CALIFORNIA

Kristine A. Kappeler Department of Geological Sciences California State University, Northridge Northridge,. California

The late early through early medial Eocene age Avenal Sandstone crops out along the west side of San Joaquin Valley, near Avenal, California. The formation has a maximum thickness of 130 m and rests unconformably on the

Upper Cretaceous Panoche Formation.

Northwest of Garza Peak, the Avenal grades vertically upward through fluvial-deltaic, sand-flat tidal-channel, sand-flat, and upper shoreface deposits.

Fluvial-deltaic deposits are channelized, matrix-supported, pebble conglomerate, which is interbedded with lenses of coarse-grained sandstone and which locally contains megafossils. The sand-flat tidal-channel deposits consist of tidal- channel lag deposits, which are pebble-conglomerate stringers, and tidal-channel sandstone-fill deposits, which are dominated by bidirectional tabular and trough cross-bedded, parallel-laminated, ripple-laminated, and convolute-bedded, well sorted, fine-grained sandstone, that locally contains beds with grading. Sand-flat deposits are characterized by Ophiomorpha-burrowed (up to 50%), moderately to

X well sorted, fine-grained sandstone. Upper shoreface deposits are fine-grained sandstone defined by an increase in burrowing to between 50% and 90%. Southeast of Garza Peak, the Avenal consists of lower shoreface deposits, which are structureless (90% to 100% bioturbated), silty to fine-grained sandstone with scattered molluscan- and discocyclinid-bearing lenses.

Sedimentary structures are rare. Degree of bioturbation increases upsection. Megafossils, including leaf debris and wood fragments, suggest deposition in a nearshore-marine environment, and the mollusks and discocyclinids are indicative of warm temperate to subtropical waters. Following uplift and erosion of Cretaceous strata, an eastward-sloping tidal-dominated delta and sand flat formed north of Garza Peak, while to the south a headland existed. Continued transgression brought lower shoreface sedimentation to the whole area. Absence of transition and locally shoreface deposits to the north indicates that the area was slightly uplifted and eroded during the early medial Eocene before being covered by the bathyal shale of the

Kreyenhagen Formation.

xi INTRODUCTION

Since 1905 the Avenal Sandstone has been the subject of several stratigraphic and paleontologic investigations, but a detailed analysis of its depositional environments has not been done. The objectives of this investigation are to divide the Avenal Sandstone into lithosomes and to interpret the depositional environment of each lithosome based on sedimentologic and paleontologic features. Refinement of the age of the formation based on megafossils is also a primary objective. Secondary objectives include the examination of subsurface characteristics and a geochemical study. The Avenal Sandstone was named by Anderson (1905) and has its type area at Big Tar Canyon (Fig. 1). Early workers referred to the Avenal by three different names (Fig. 2). In recent years there has been some thought given to whether the name "Domengine Formation" (named by Anderson, 1905, for exposures 40 km northwest of the area) should be used instead of the name

"Avenal Sandstone". In this report the name "Avenal Sandstone" will be used because 1) it was named for the exposures in the study area, 2) the name has priority over the "Domengine Formation", and 3) to date, no one has shown that the Domengine Formation and the Avenal Sandstone are the same stratigraphic unit. The late early through early medial Eocene age Avenal Sandstone crops out for 29 km along Reef Ridge on the west side of San Joaquin Valley, southeast of

Coalinga, in western Fresno and Kings Counties, central California (Fig. 1). It rests with angular unconformity (150 to 30°) on the Upper Cretaceous Panoche

Formation, unconformably underlies the lower middle Eocene Kreyenhagen

Formation, is overlapped by the upper to middle Miocene McLure Shale Member

1 i 2

N -----1·: i l .;._,:··· .. •.. "...... " <, ~ .... "

0 ~ +, .... " .. :

__ __.l.I

..... N 1 ...... ·- ~----~· Figure 1. Index map of study area and vicinity showing major physiographic features and surface exposures of the Avenal Sandstone (modified after Stewart, 1946). Arnold, Ralph, and Von EstroH. F.E., 1930; A.D., and Hollister, J.S., This paper :1 II) Anderson, F.t.t., Clark, B.L, Reed, I UJ Anderson, Robert, and 1936; Ge&ter, G.C., Galloway, i ~ a: 1905 John, 1933; 1935 Woodring, W.P., and others, 1940; 1984 >- UJ uuo II) II) Goudkolf, P.P., 1934 Weaver, C.E., and others, 1944; Stewalt, Ralph, 1946

KREYENHAGEN TEJON KREYENHAGEN i\ouGOCENE/ KREYENHAGEN KREYENHAGEN >- a: UJz ~ UJ KREYENHAGEN 1-a: 8 ~ w AVENAL TEJON OOMENGINE AVENAL AVENAL AVENAL

II) ::;) CHICO KNOXVILLE-CHICO KNOXVILLE..CHICO SHASTA..CHICO PANOCHE PANOCHE II) 0 J UJ 0 u w -< u IU a: u a:~ a: u UJ D. D. J ···-

Figure 2. Summation of names and age assignments of formations on Reef Ridge (modified after Stewart, 1946).

w 4

of the Monterey Formation to the southeast, and is overlapped by the lower

Miocene Temblor Formation to the northwest (Fig. 3). Areas of best exposure of the Avenal Sandstone are Big Tar Canyon area, Garza Canyon, Canoas

Canyon, Reese Canyon, Arroyo Pinoso, and Zapato Canyon (Figs. 1, 3, and 4).

Elsewhere the formation is mostly covered.

Ninety-five percent of the Avenal Sandstone is a thick- to thin-bedded, fossiliferous, fine- to coarse-grained sandstone. Five percent of the formation is a pebble conglomerate that occurs in the basal portion of the formation and ranges in thickness from 0 to 7 m. The formation has a maximum thickness of

130m. Active oil seeps and tar springs occur locally toward the top of the Avenal.

In the North Dome of the Kettleman oil field, 10 km to the east of the study area, the Avenal Sandstone's equivalent is an oil-producing horizon.

The subsurface Avenal Sandstone as identified in the study area is referred to in drill reports as the McAdams sand. The name "McAdams sand" has been designated equivalent to the Avenal Sandstone by the Geological Survey and is used by the California Division of Oil and Gas. To the east from Reef Ridge in

Kettleman Hills and Jacalitos oil fields (Fig. 5), the McAdams (Avenal) can consist of an upper and lower member referred to as upper and lower McAdams sands (Fig. 6). The Avenal is probably equivalent only to the upper McAdams when both are present. The Avenal Sandstone equivalent is present beneath

Kreyenhagen Hills, Kettleman Hills, Jacalitos, and possibly Coalinga eastside area and Pyramid Hills oil fields (Fig. 5).

In this attempt to examine the subsurface characteristics, it became apparent that scarcity of data and lack of knowledge still exist today when dealing with Eocene strata in the San Joaquin Valley. Many questions remain unanswered as to ages and equivalent deposits. ·--·-\ ~ ..

...... Tt

Alluvium Temblor Fm. ~ [!Q Miocene ~, [!!U Tulare Aft. [!LJ Kreyenhaven All. Pleiatocent Eocene [!!] San .Joaquin F111. Avenal SandttOM 0 2mi Pliocene m Eocene 1 1 t I I I Etchevoin Aft. Cretactoua undiHertntlated 0 311m ~ Pliocene ~ [ji] R.. f Rid91 Shalt / contact K ayncllnt leeleiJ IIIUilied otter T. W. 0111111 .., .Jr,, D. w. Fro111n , Miocene ,_,- fault anti clint c.c. Cllurcll, 1111d E.H. StelnllleJtr (1971). Me Lure Shale ~ ~ ..&- attitude _760 c SuN mevafo1111 locality Miocene of bed• • ole eample Figure 3. Generalized geologic map of Reef Ridge showing areal distribution of the Avenal Sandstone, major faults of the area, and megafossil localities (geology modified from Dibblee, 1971-1974).

V'l c•t\iot\ 1.•<~•'0 c•t\"ot\ f'\t\o•o ,_,,o'lo

t c•t\"ot\ e'o 1•c t.••' 0 e\0 1•c AVENAL SANDSTONE &9'\(\0 ~ 0 3 km ~oo MEASURED SECTIONS ' / .\.,,,,. 1•c c•t\"ot\ cat\'fot\ u\t~"uc Figure 4; Location of measured sections through the Avenal Sandstone at Reef Ridge, Kings and Fresno Counties, California.

0'1 7

:::::::::: ..·.·.···... -~:······... ~- ...... ; .. :·:; \-..~::.

-::::::. aTUDY AREA

0 :tiOicm //;:::::;:: OIL FIELD '\'\\, 0 tZmi \ ·· ..

Figure 5. Location of oil fields and structures within the vicinity of the study area (modified after Woodring and others, 1940). 8

Avenal Sd.

?t ~ C Lower~ ~ cAdams _:::::s:

Hondo Shale

Figure 6. Type E-log for Jacalitos oil field, H. C. Lillis No. 1 (sec. 28, T21S, R16E). 9

A geochemical comparison between an outcrop sample of the Eocene

Kreyenhagen Shale and oil from a seep in the underlying Avenal Sandstone was carried out by the Getty Oil Company Research Center to determine whether the shale sample could have generated the seep oil. The Kreyenhagen sample was collected near Arroyo Pinoso, Kings County (NE sec. 26, T22S, R15E) (Fig.

3). The oil sample was collected from a seep 25 km to the southwest (SE sec. 20, T23S, R17E) (Fig. 6). PREVIOUS WORK

Following Anderson's (1905) naming of the formation, the Avenal Sandstone was mapped and further described by Arnold (1910), Arnold and Anderson (1908,

1910), Gester and Galloway (1933), Siegfus (1939), Clark (1935), Stewart (1946),

Addicott (1970, 1972), and Dibblee (1971-1974). Megapaleontologic data were reported by Arnold (1910), Arnold and Anderson (1910), Vokes (1939), Wells

(1940), and Stewart (1946). Benthonic foraminiferal data were reported by

Laiming (1940a, 1940b, 1943), Crume (1940), and Mallory (1959). Subsurface studies of the Avenal Sandstone at Kettleman Hills oil field were done by Gester and Galloway (1933), and Woodring and others (1940). Bodden (1983) and Cherven

(1983a) studied the depositional environments of the middle Eocene Domengine

Formation of the southern Sacramento Basin. Moreland (in preparation) is presently working on a reconstruction of the depositional environments of the

Avenal Sandstone along Reef Ridge. Kappeler and others (1984) interpreted the depositional environments of the Avenal Sandstone along Reef Ridge as a preliminary article to this thesis project.

10 METHODS

Six stratigraphic sections {Fig. 4) were measured by means of tape-and

Brunton and Jacob-staff methods, and additional exposures were studied between

the measured sections. The designated type section at Big Tar Canyon was not

measured because of poor exposure. Figure 7 shows the explanation for the

drafted measured sections that are shown in Figures 8 to 13. Locations of thin

section samples and observed megafossils are designated in Figures 8 to 13.

Laboratory analysis included study of thin sections, determination of grain

size distribution by dry sieving, identification of heavy minerals and

conglomerate clasts, and determination of grain angularity and shape. Thin

sections were cut from 19 rock samples (Table 1) and a petrographic analysis was

undertaken in order to determine the composition (Fig. 14), textural properties,

and diagenetic history of t~ese rocks. One-half of each slide was stained for

potassium feldspar. Percent composition was determined by point counts of 250

points per thin section, using a point-count microscope attachment. Grain-size

distribution by dry sieving for 15 minutes on a Ro-Tap machine was done on 10

samples. Heavy-mineral analysis was done on five samples (Table 2). Descriptions of conglomerate beds include clast-to-matrix ratio, clast

composition, angularity and shape. Clasts were collected by placing a Jacob

staff on the outcrop approximately parallel to the strike of the bed and then · removing 25 pebbles which touched the staff, generally at four localities within

each section. Clast composition was then determined in the laboratory (Table 3).

Lithologic colors are according to the rock-color chart distributed by the Geological Society of America (Goddard, 1980). Grain-size classification is from

11 12

EXPLANATION

LITHOLOGY STRUCTURE

SHALE GRADED

0 FLOATING CLASTS -s.-. RIP-UP CLASTS MEDIUM • CARBONIZED WOOD

COARSE = "' ~ CARBONACEOUS MATERIAL

VERY COARSE TO CHANNELS GRANULAR &~ ·.·.·:.·.·.·.·.·.·.·.· LAMINATED OR THIN PEIIBIE } ~ ; BEDDED ..,:;~::.:.:;:<··' CROSS BEDDED ~ z (0 CONCRETIONS 0 u c:J COVERED

RIPPLE BEDDED

BED FORMS SYMBOLS

(·.·.·.·.·.·.! FLAT ' OIL SEEP BTE-4,CC-5,etc. THIN SECTION NUMBERS jl MEGAFOSSILS ~LENS 780- CSUN MEGAFOSSIL LOCALITY

c;::::o:;:;::o' CHANNELl ZED y TRACE FOSSIL

Figure 7. Explanation for measured stratigraphic sections. 13

BIG TAR EAST (BTE) SECTION

Avenal Kreyenhagen Sand atone 80 Formation 88.7 m. ~~·

CD 30 70 a: lower atGiilface ...w lower shoreface w :E BTE-4 20 80

10 ,_ BTE-2

764

0 Panoche Formation BASE OF SECTION COVERED

Figure 8. Stratigraphic section of the Avenal Sandstone measured along the north side of Big Tar East, NE~ of section 20, T23S, R17E, Garza Peak quadrangle, California. 14

GARZA CANYON (GC) SECTION

Avenal Kreyenhagen Sand atone Formation

-104.8 m. l&ndtlat

50 100

~1-daaelllg sand flat

tktak:hamel llg 80 40 I4JP8I' aholeface eand flat ~1-daaellllg

30 80 CD •nd flat a: w .... tidal-daaellag w :E 20 70

GC-6 tidal-dameI aandstone-4111 10 80

...... 0 GC-2

.. ,·: ~ GC-Kr ~~~·~·~·w Panoche BASE OF SECTION Formation COVERED

Figure 9. Stratigraphic section of the Avenal Sandstone measured along the south side of Garza Canyon, N~ of section 10, T23S, R16E, Garza Peak quadrangle, California. 15

CANOAS CANYON (CC) SECTION Kreyenhagen Avenal Formation Sandatone 130 --129.7 m.

eandtlat IClP8I' ahoreface eo 120 tldal-ctamel lag andlat tldal-ctamel eandat~flll 60 tidal-channel lag 110 aand tlat tlda H:hannel aandatone-flll tldal-ctannel lag Jl tldal-ctamel 40 eandat~flll 100

tidal-channel lag (I) a: and flat w eand flat .... w 30 90 :E cc-e Jl. tidal-channel • 0 a.ndstone-flll 0 0 20 eo ...tlat tldal-ctannellag

0 .. 0. 000 T· and flat 0 '[pJ ... 0 • tidal-channel • • • 0

eandat~flll ~-.....·~·:.·.::.· .. - ...... 10 70 ::~·::-.·;;.

0 . tidal-channel lag r·· . and tat

Panoche Formation Figure 10. Stratigraphic section of the Avenal Sandstone measured along the south side of Canoas Canyon, SE\ of section 32, T22S, R16E, the Dark Hole quadrangle, California. 16

REESE CANYON (RC) SECTION

Avenal Sandstone

80 tlda J-cl"'arwwl a.g RC-8 Kreyenhagen .-..- Formation aand tat tldaJ-chamellag

50 aand flat 120

tldaH:hannel lag

..Stat

tldaJ-chamellag 40 110 ....Sflat IClP8I' ahoraface Cl) a: w tldaJ-chamel lag ~ w 30 100 :E tclal-<:harnel •ldatone-.

ldal-chamellag

20 90

tldal-<::tarral •ldabe-.

10 ~RC-8 80

0 70 Panoche aandflat Formation RC-Kr

Figure 11. Stratigraphic section of the Avenal Sandstone measured along the south side of Reese Canyon, NE\ of section 31, T22S, R16E, Garza Peak quadrangle, California. 17

ARROYO PINOSO (AP) SECTION

Avenal Kreyenhagen Sand atone- Formation

111.1m. 110

und flat und flat tldakhamel llg tldat-chamel lag eand flat 60 100 Und flat tkBI-dlamel lag

und flat

tkBI-dlamel lag 40 tldakhamel Jag 10

eand flat fD a: aand flat w tldat-chamel Jag ... 30 80 w und flat ~ tldakhamel Jag

20 70 .· . ·T· AP-11 .:-r·. :-.· .· und flat tldal-chamel . 0 • . eardston~t-flll ..•.. tldakhamel Jag tidal-channel lag und flat 10

tidat-chamel lag

~ AP-8 tlda 1-chamel lag :;:;\/~~·~~-:~~~~: tblal 0 ~ AP-Kr Panoche Formation Figure 12. Stratigraphic section of the Avenal Sandstone measured along Arroyo Pinoso, NE~ of section 35, T22S, R15E, Garza Peak quadrangle, California. 18

ZAPA TO CANYON {ZC) SECTION

Temblor Formation

88nd flat

tldakhamel Jag

60 tldal-chamel aandatone-flll

tldakhamel lag zc:..1 tldakhamelaandstone-flll ZC-8 aand flat 40 tldaktamel Jag tldal-chamel aandstone-flll tldaH:hamel lag

~ a: w 30 Avenal ~ Sandstone w ~

10 ......

• --- 789

Panoche Formation

Figure 13. Stratigraphic section of the Avenal Sandstone measured along the south side of Zapata Canyon, NE~ of section 21, T22S, R15E, Kreyenhagen Hills quadrangle, California. TABLE 1. PETROLOGY AND FIELD LOCATION OF ROCK SAMPLES

SAMPLE FIELD LOCATION PERCENT COMPOSITION AVG. TEXT. ROCK NAME (after Folk, 1980) au PLAG OATH RF CACM OTCM OT so AD 8m above base of fine aand•tone: calcitic mature AP-6 I frroyo Pinoso section 29.6 0.4 22.8 2.4 44.4 0 0.4 w A F1g. 11) arkose Near Base of Reese line sandstone: calcitic submature RC·6 fanyo~) Seclion 26.4 1.6 20.0 2.8 46.4 0.4 2.4 M SA I Fig 10 b10titic arkose 22.5m above base of Big line sandstone: calcitic mature BTE-4 I ~~~ C~nyon East section 34.8 6.4 13.2 4.0 37.6 0 4.0 w SA F1 . 7 biotitic arkose Near middle of Reese line sandstone: phosphatic eubmature RC-9 section 39.6 1.2 29.2 10.8 12.4 0 6.8 M SA I ~anyon muscovitic arkose ~ 18m above base of line sandstone: phosphatic submature CC-5 I ~anoas Canyon section 41.2 3.2 22.4 9.6 0 12.4 1t.2 M SA F1g. 9) _ muscovitic arkose 20m above base of CC-6 22.0 2.4 20.0 5.6 42.4 0.4 5.2 w SA line sandstone: calcitic mature ~~~o~~ Canyon section micaceous arkose 15m above base of fine sandstone: calcitic mature GC-6 Garza Canyon section 27.6 0.8 14.0 4.8 40.8 2.4 9.6 w SA (F~ muscovitic arkose Near m1ddle of line sandstone: calcitic subrnatura GC·9 i ?arza Canyon section 9.2 2.4 3.6 1.6 79.2 0 4.0 p SA F~ plant-bearing arkose Near top of Zapato coarse sandstone: hematitic phosphatic ZC-6 40.0 1.2 23.6 13.2 0 12.8 9.2 M SA I f(;~Y~~ 1 section submature micaceous claystone-bearing arkose 40m below lop of line sandstone: lerrugenous mature AP-11 44.2 3.1 t7.7 10.4 0 8.4 16.2 w SA ~V;~Y~ ~inoso section muscovitic claystone-bearing arkose 2m above base of Big fine sandstone: phosphatic submature BTE-2 Jar C~nyon East section 41.6 4.8 20.0 5.6 0 23.2 4.8 M SA Fig. 7 muscovitic arkose At base of Garza fine sandstone: calcitic mature GC-2 29.2 4.0 6.8 4.4 48.8 0 6.8 w SA ~~~y~r section biotitic arkose 23m above base of medium sandstone: calcitic mature GC-t I ~~~z~ canyon section 25.2 1.6 18.0 1.2 5t.6 0 2.4 M SA 1 arkose 24m abo"iie base of fine sandstone: calcitic phosphatic mature GC-tl I rarz~)Canyon section 29.2 3.6 28.4 tO.O 11.6 8.0 9.2 M SA Fig 8 muscovitic arkose 1om below lop ol fine sandstone: submature muscovitic ZC-7 I fapato Canyon section 5t.6 2.4 25.6 t0.8 0 0.4 9.2 M SA Fl~-- glauc~nilic quartzite-bearing arkose Upper Cretaceous contact medium sandstone: calcitic submatura AP-Kr trrgyo Pinoso canyon 24.8 4.0 t9.2 7.2 36.0 0 8.8 M SA 1 Fl .:...2.!1._ micaceous quartzite-bearing arkose Upper Cretaceous contact coarse sandstone: calcitic submature RG-Kr I reese Canyon 24.4 7.2 16.0 8.8 34.8 0 0.6 M SA Flg.10) m~eaceous quartzite-bearing arkose Upper Cretaceous contact coarse sandstone: calcitic submature GC·Kr Garz~ canyon 24.0 4.0 9.6 t6.8 33.6 0 22.0 M SA 1':!.!!.8 1 biotitic quartzite-bearing arkose Upper Cretaceous contact medium sandstone: calcitic submatura CC·Kr Canyon 21.6 8.0 12.8 4.8 35.2 0 17.6 p SA I ~ano:~Fig. 9 biotitic arkose KEY' ..._."-""",QU .. Ouaru,PI.AO- Plogooclaoo.OIIlH- Orlhoclua.Rf ·· Rod

..... \0 Q Q

n=11 n-11

MEAN MEAN 0 aa F37 Ra 0 e1 P33 K,

F 3:1 1:1 1:3 R p K

0 AVENAL SANDSTONE Q TOTAL QUARTZ X PANOCHE FORMATION F TOTAL FELDSPAR R TOTAL ROCK FRAGMENTS P PLAGIOCLASE K POTASSIUM FELDSPAR

Figure 14. Ternary diagrams showing composition of sandstones of the Eocene Avenal Sandstone and Cretaceous Panoche Formation.

N 0 21

TABLE 2. HEAVY MINERAL ANALYSIS OF FIVE SAMPLES FROM THE AVENAL SANDSTONE AT REEF RIDGE

HEAVY MINERAL COMPOSITION

.Sample Number AP-11 ZC-8 ZC-7 RC-7 CC-5 Mean Percent Uthofacies SF TCF TCF TCF SF

Mineral

Magnetite 6.4 5.3 4.0 7.3 4.6 Ilmenite 12.3 7.9 9.0 22.0 7.5 11.7 Leucoxene 34.2 32.8 36.6 55.4 75.0 46.8 Limonite 16.1 5.3 10.1 6.3 Hematite 12.2 21.1 20.8 25 11.3 Zircon 5.2 7.9 11.7 6.0 2.5 6.6 Tourmaline 13.6 7.9 3.9 4.1 12.5 8.4 Hornblende 1.3 1.0 0.5 Apatite 1.3 1.0 0.5 Gamet 11.8 1.3 2.9 3.2 Biotite .3 0.1

Total Percent 100.0 100.0 100.0 100.0 100.0 100.0

_ =absent SF = sand-flat TCF = tidal-channel sandstone-fill

SEPARATION YIELD

Sample Initial Heavy Light %Heavy %Light Percent Number Weight Min.Wt. Min. Wt. Minerals Minerals Loss

AP-11 1.642 .004 1.632 0.245 99.755 0.39 ZC-8 1.788 .002 1.622 0.123 99.877 3.61 ZC-7 1.769 .005 1.759 0.283 99.717 0.32 RC-7 1.818 .002 1.796 0.111 99.889 1.08 CC-5 1.762 .002 1.709 0.117 99.883 2.95 TABLE 3. COMPOSITION OF CONGLOMERATE SAMPLES FROM THE AVENAL SANDSTONE AT REEF RIDGE SIZE(CM) SAMPLE CLAST COMPOSmON PERCENT SHAPE ROUNDNESS ~s RANGE I AVERAGE ZC-2 ZAP ATO CANYON BLACK CHERT 57 2.0·0.5 1.0 EQUANT ROUNDED FLUVIAL METAVOLCANIC 7 2.0·1.0 1.5 EQUANT SUB ROUNDED QUARTZITE 28 2.75-0.5 1.0 EQUANT ROUNDED SHALE 3 1.0-0.5 1.0 OBLATE SUBANGULAR SANDSTONE 1 2.0-1.0 2.0 EQUANT SUBROUNDED JASPER 1 1.0·0.5 1.0 PROLATE SUBROUNDED GRANITE 3 2.0·1.0 1.5 EQUANT ROUNDED RC-1 REESE CANYON QUARTZITE 30 8.0·0.5 2.5 EQUANT ROUNDED FLUVIAL SANDSTONE 32 6.0·1.0 2.0 EQUANT SUB ROUNDED SHALE 5 2.5-1.5 1.5 OBLATE SUBROUNDED GRANITE 5 3.0·1.0 2.5 EQUANT WELL ROUNDED I METAVOLCANIC 7 3.5·1.0 2.5 EQUANT WELL ROUNDED BLACK CHERT 18 3.0-0.5 1.5 EQUANT WELL ROUNDED CHALCEDONY 3 2.0·1.0 1.5 PROLATE SUBROUNDED I RC-10 REESE CANYON BLACK CHERT 15 3.0-0.5 2.0 EQUANT WELL ROUNDED : TIDAL-CHANNEL LAG QUARTZITE 50 4.0-.75 3.0 EQUANT WELL ROUNDED SANDSTONE 26 4.0-.5 2.0 EQUANT WELL ROUNDED GRANITE 3 2.0-1.5 1.5 EQUANT WELL ROUNDED META VOLCANIC 6 3.0·2.0 2.5 EQUANT SUBROUNDED

GC-2 GARZA CREEK QUARTZITE 43 7.0-1.0 1.0 EQUANT ROUNDED FLUVIAL GRANITE 3 1.5-1.0 1.0 EQUANT ROUNDED BLACK CHERT 29 3.0-0.5 1.5 EQUANT WELL ROUNDED META VOLCANIC 5 3.0-1.0 1.0 EQUANT WELL ROUNDED SANDSTONE 20 2.5·1.0 1.5 EQUANT WELL ROUNDED AP-7 ARROYO PINOSO BLACK CHERT 27 3.5-1.0 2.5 EQUANT WELL ROUNDED TIDAL-CHANNEL LAG QUARTZITE 31 4.0·2.0 3.0 EQUANT WELL ROUNDED SANDSTONE 34 4.0·1.0 2.0 EQUANT SUBROUNDED GRANITE 4 2.0·0.5 2.0 EQUANT WELL ROUNDED META VOLCANIC 4 5.0·2.0 2.0 EQUANT WELL ROUNDED

N N 23

Wentworth (1922), rounding is from Powers (1953), shape is from Zingg (1953), and sorting, maturity, and rock names are from Folk (1980). Nomenclature and definitions of environments are from Reineck and Singh (1980).

An examination of the Avenal Sandstone in the subsurface of Jacalitos oil field and downdip from the Reef Ridge outcrops in Kreyenhagen Hills was compared with the results of the surface analysis. These areas were selected due to availability of data. Subsurface studies include: (1) the examination of electric logs of the Jacalitos oil field wells and description of the lithologic characteristics on logs of the Avenal Sandstone; (2) analysis of isopach maps and cross-sections constructed from correlations; and (3) core descriptions, where available, were used to compare subsurface to surface lithology. Seven major cross sections were set-up approximately N-S and E-W across the San Joaquin Valley in an attempt to correlate E-logs of wells in the nearby oil fields. Outcrop descriptions of the Avenal were used to compare with well core descriptions, mud logs, and paleontology samples of subsurface strata where available.

A Kreyenhagen shale sample (Fig. 3) was subjected to a number of geochemical measurements which included total organic content (TOC), Rock

Eval pyrolysis, visual kerogen assessment, vitrinite reflectance, and extraction of C15+ soluble organic matter by standard chromatographic techniques (Appendix 1). Similar chromatographic methods were used to analyze seep oil from the Avenal Sandstone (Fig. 8). A sample of sand was also analyzed for total organic carbon content.

Megafossils, collected from ten localities (Fig. 3; Appendix 2), were identified by R. L. Squires (Table 4) and are housed at California State

University, Northridge. Microfossil samples were collected from sandstones in the northern part of the field area, but they were all barren. Preparations were 24

TABLE 4. MEGAFOSSILS FROM THE AVENAL SANDSTONE, REEF RIDGE, FRESNO AND KINGS COUNTIES, CALIFORNIA LOCALITIES

MEGAFAUNA i760 761 762 7631764 765 766 767 768 769 Large ~UKAM1NI~lKA Pseudophragmina (Proporocyclina) clarki (Cushman, 1920) X X X SCLERACTINIA Astrocoenia? sp ••••••.• X ?D1scotrochus californicus Wells X Turb1noha? sp. X un1dent1f1ed solitary coral X ANNELIDA Rotularia tejonense (Arnold, 1910) X X X X SCAPHOPODA Dental ium (Laevidentalium) calafium Yokes, 1939 X X GASTROPODA Amaurellina caleocia Yokes, 1939 X Arch1tectoni~laxisl c]§!6ja Gabb, 1864 X 81tt1um dumblei !D1ckerson, .•...• X BOneTTltlaiTACmetula) paucivaricata (Gabb, 1864) X Ca1yptraea d1egoana (Conrad, 1855) .. X X Conus horni1 umpquaensis Turner, 1938 . X X Conus n. sp. • X ryl1Chnina tantilla (Anderson and Hanna, 1925) X X Domenglne1latCTaYfOnensis (Gabb, 1864) ..• X Ect1noch1lus !Hac1lentosl macilentus (White, 1889) X X X X X X Eocerm na hanm ba 11 01 ckerson, 1914 X X X X X F1cops1s remond11 crescentensis Weaver & Palmer, 1922 X ROmalOPOm~ umpquaens1s Merriam &Turner, 1937 X Le1orh1nus? ree01 Stewart, 1946 X Lyr1a anders~aring, 1917 X ~nella ([eptegouana?) hulini Vokes, 1939 X Ho1opophorus ant1quatus (G~B64) X Ner1ta (Amphinerlta) eorex Vokes, 1939 X Never}ta (Neverlta) g1{toka Gabb, 1869 X liTequama d0iiieiig1nica o es, 1939) • X X Ollve1la mat~ewson11 (Gabb, 1864) X ~omm1u~ clark1 (Stewart, 1927) X X X Paraseraphs erratTCUs (Cooper, 1894) X Phal1um !Sem1cass1s) tuberculiformis (Hanna, 1924) X POTTnTCes !Eusp1ral nuc1form1s (Gabb, 1864) X X Prox1m1tra? cretacea (Gabb, 1864) X Pseudol1va? ~ • X Ranell1na pilsbryi Stewart, 1927 X Surcul1tes-matheWSonii (Gabb, 1864) X Turrltel1a anderson1 lawsoni Dickerson, 1916 X Turr1tel1a buwa1dana D1ckerson, 1916 X X X X X Turrlte11a uvasana aedificata Merriam, 1941 X X X Turrlte11a uvasana n. subsp.? X IIIUrlCld X naticid X X turrid X unidentified gastropods X BIVALVIA Acanthocardia (Schedocardia) brewerii (Gabb, 1864) X X Cla1born1tes diegoens1s (Dlckerson, 1916) X Corbu1a compl1cata Hanna, 1924 X ~undulata Vokes, 1939 X bJYCymerls (Giycymerita) sagittata (Gabb, 1864) X X X X X Glyptoacbs domeng1n1ca (Vokes, 1939) .•... X ? X ? Nemocard1um (Nemocard1um) linteum (Conrad, 1855) X Nucu1ana (Sacce11al chaney~. 1939 •.. X P1tar (Lame111concha) JOaquinensis Vokes, 1939 X X X X X Sp1sula mernam1 Packard, 1916 • X X TeTTTna ~oledadensis Hanna, 1927 X Tei'edO? sp. - • • • . . X venerlcardia (Pacificor) aragonia joaquinensis (Vokes, 1g39) X X Vener1card1a sp. 1ndet. X ostre1d X X X pitarids X X X sol enid X X unidentified bivalves X X X BRACHYURAN unidentified crab cheliped X CHORDATA unidentified aammal? bone X PLANTAE unidentified wood fragments X X 25

done by Green and Associates, Paleontological Services, Whittier, California (Appendix 3). il .

AGE AND CORRELATION

The Avenal Sandstone is of late early through early medial Eocene age based on mollusks and benthonic foraminifers (Fig. 15).

Clark and Vokes (1936) originally proposed a chronological sequence of molluscan provincial "stages" for the West Coast Eocene. Their sequence was used by Vokes (1939) and Weaver and others (1944) who assigned the Avenal

Sandstone (or strata equivalent to it) to the "Domengine Stage". Givens (1974) revised the original concept of the "Domengine Stage" by including within it, the upper faunal zone (!_.~., the Galeodea susanae Zone) of the underlying "Capay

Stage" of Clark and Vokes (1936). Givens' (1974) revised "Domengine Stage" is used herein. Based on calcareous nannofossils and mollusks in the Simi Valley,

California area, Saul (1983a) reported the "Domengine Stage" as revised by

Givens (1974) to be of late early through early medial Eocene age.

The Avenal Sandstone contains, throughout its entire thickness, megafossils that have been reported (Givens, 1974; Givens and Kennedy, 1979; Saul, 1983a;

Squires, in press) elsewhere on the West Coast only from the revised "Dornengine

Stage". Such taxa found in the course of this present work are Dentalium

(Laevidentalium) calafium, Lyria andersoni, Olequahia dornenginica, Proxirnitra? cretacea, Turritella andersoni lawsoni, Claibornites diegoensis, Gari eoundulata, and Pitar (Lamelliconcha) joaquinensis. Turritella uvasana aedificata, which was also found in the course of this present work, has been reported by (Merriam,

1941) as indicative of the "Domengine Stage".

Other Avenal Sandstone taxa that are restricted to the "Domengine Stage" and which have been reported by others (Anderson, 1905; Vokes, 1939; Stewart,

1946), but not found in the course of this present work, are Ancilla (Spirancilla)

26 PACIFIC COAST BENTHIC FORAMINIFERAL PALEOGENE ZONE CALCAREOUS NANNOPLANKTON PLANKTONIC ~w EUROPEAN PROVINCIAL STAGES ZONES ZONES III~ SERIES OR! FORMATIONS MOLLUSCAN STAGES FORAMINIFERAL "< STAGES CLARK & VOKES (1936) LAIMING (1940a, MARTINI ( 1971) BUKRY &OKADA >:u SUBSERIES MALLORY (1959) BEAGGR ~ N, KENT) (1980) ::::t(J) GIVENS (1974) 1940b, 1943) & FLYNN1 1n1 oreu. SAUL(1983) i NP16 45 A-1 P12 "TEJON" NARIZIAN - KREYENHAGEN IJ.I LUTETIAN f------FORMATION NP15 ..I A-2 P11 CP13 0 r------IJ.I ------0 "TRANSITION" A-3 - z f------/ ------so- 2 / IJ.I / B-1A P10 / - "DOMENGINE" / ------CP12b () NP14 AVENAL I-- 0 ULATISIAN I CP12a B-1 pg SANDSTONE I IJ.I I NP13 CP11 - >- >------..I YPRESIAN 1------I PS 55- a: I NP12 CP10 "CAPAY" I B-2 - c IJ.I I P7 NP11 CP9

I .

Figure 15. Correlation chart of various authors for comparison of the age assignment of the Avenal Sandstone (compiled by author for generalized comparison).

N " 28

gabbi, Conus caleocius, Cypraea castacensis, Fusiturricula (Crenaturricula) crenatospira domenginica, Pseudoliva lineata, Xenophora stocki, and Spondylus carlosensis.

A "Domengine" age, based on mollusks for the Avenal Sandstone, is in agreement with Laiming's (1940a, 1940b, 1943) age based on benthonic foraminifers. He reported the Avenal to contain foraminifers indicative of his tentative B-1 Zone which he considered equivalent to the "Domengine Stage".

Mallory (1959) assigned the Avenal to his West Coast benthonic foraminiferal

Ulatisian Stage. This stage is time transgressive (Poore, 1980), but includes the

"Domengine Stage".

The mollusks of the Avenal Sandstone are very similar to those reported by

Givens and Kennedy (1979) for the "Domengine" age La Jolla Group, San Diego,

California. Much of the megafauna reported by Squires (in press) for the

"Domengine"-age part of the Llajas Formation, Simi Valley, California, is conspecific with that of the Avenal. Turritella buwaldana and Turritella andersoni lawsoni are also present in the lower portion of the Llajas Formation.

The Avenal Sandstone megafauna is also very similar to that reported by Squires

(1977) for "Domengine"-age unnamed strata in lower Piru Creek, Transverse

Ranges of California. In the Pine Mountain region of the Transverse Ranges, the

"Domengine"-age Turritella uvasana applinae megafauna of the Juncal Formation

(Givens, 1974) is very similar to that of the Avenal Sandstone. GEOLOGIC SETTING

STRUCTURE

The Avenal Sandstone crops out along the west side of Reef Ridge. Reef

Ridge forms the northwestern flank of the Diablo Range and joins the western edge of the San Joaquin Valley, south of Coalinga and west of Kettleman Hills

(Fig. 1). The ridge is underlain by one of several large southeast-trending, en echelon folds developed subparallel to the San Andreas fault (24 km to the west)

(Fig. 5). The ridge extends northwest from Pyramid Hills in the south to Zapato

Canyon in the north. The Kreyenhagen Hills lie to the northeast between Reef

Ridge and Kettleman Plain with the younger (Pleistocene) Guijarral Hills

Kettleman Hills beyond (Fig. 1). McLure Valley (also referred to as Sunflower

Valley) lies to the southwest.

Reef Ridge forms a portion of an eroded and faulted anticlinal structure with Tertiary strata dipping as much as 850 to the east. No major faults are recognized in the field that cut the Avenal Sandstone, although one fault has been mapped by Stewart (1946) and Dibblee (1971-1974) in Big Tar East (Fig. 3).

In the subsurface, however, two major faults, the Castle Mountain and Curry

Mountain are recognized.

The northwest-striking Castle Mountain fault, just southwest of the study area (Figs. 3 and 5), is a high-angle reverse fault with some left lateral motion.

The southwest side is down according to Fowkes (1982), which is confirmed by subsurface information provided by D. W. Frames. Maximum displacement is 23 m. North of the Castle Mountain fault is the northwest-striking Curry Mountain fault (Fig. 5). It is a high-angle (600) reverse fault with a minimum displacement of over 305 m (Clark, 1935). The Castle Mountain fault cuts the

29 30

Miocene Reef Ridge Shale in the study area, and it possibly resulted from shear associated with the San Andreas fault system. At least four folding events within the study area are suggested by examination of the geologic map and cross sections. The first event was pre-

Avenal folding when the Cretaceous section was tilted to the east, subsequently eroded, and unconformably (angular discordance of 150 to 300) overlain by the

Eocene Avenal Sandstone. The second event was post-Avenal uplift and erosion of parts of the Avenal Sandstone. The transition zone environment was eroded in all areas, and in some localities in the northwest, the lower and upper shoreface environments also were eroded away. The Avenal Sandstone was subsequently overlain unconformably by the bathyal shale of the Kreyenhagen Formation. The third event was post-Kreyenhagen folding (or was related to a lower sea level during the Oligocene) noted in the northwest by the absence of the Kreyenhagen and by the unconformable sedimentation of the Miocene Temblor Formation overlying the Eocene Avenal. The fourth event was post-Temblor folding recognized in the southeast by uplift and erosion of the Miocene Temblor,

Eocene Kreyenhagen, and Avenal formations followed by the unconformable deposition of the Miocene McLure Shale.

STRATIGRAPHY

Reef Ridge cd\.tains a stratigraphic section of Cretaceous through

I Quaternary fossiliferous sedimentary rocks with some volcanic ash (Fig. 3). The

Eocene Avenal Sandstone lies unconformably upon deep-marine turbidites of the

Upper Cretaceous Panoche Formation throughout the study area (Fig. 2). The

Panoche Formation (approximately 6,000 m thick) consists Of a series of alternating sandstone, dark thin-bedded silty shale, and locally thick conglomerate (Anderson and Pack, 1915; Mansfield, 1972) beds. Environments of 31

deposition include low- and high-energy turbidite deposits, grain flow, and subaqueous debris-flow deposits as interpreted by Mansfield (1972). For detailed information regarding the Panoche Formation refer to Arnold and Anderson

(1910), Arnold and Pack (1915), Marsh (1960), Anderson (1972), and Mansfield

(1972).

The late early through early medial Eocene Avenal Sandstone of Reef

Ridge is unconformably overlain by the lower middle Eocene Kreyenhagen Shale as depicted on Figures 3 and 4. The Kreyenhagen has a maximum thickness of about 305 m and consists predominantly of thin-bedded, purplish-brown, hemipelagic shale, with a few lenticular beds of sandstone, and local lenses of limestone (Addicott, 1972). The basal 30 m of the formation was named the

Canoas Siltstone Member by Cushman and Siegfus (1939) for exposures on Garza

Creek (Fig. 1). The Canoas Siltstone contains calcareous nannoplankton taxon R. inflata, which is the zonal marker taxon of Bukry (1973) R. inflata subzone which is of early medial Eocene age. The Canoas member is also recognized in the subsurface. Above the Canoas, beds reveal an upward sequence of argillaceous, calcareous, and siliceous shales containing an abundance of foraminifers and diatoms. Samples taken from the Kreyenhagen (Canoas Siltstone) just above the

Avenal contact in the study area contain bathyal foraminifers as identified by

Green and Associates. Radiolaria are abundant in the upper Kreyenhagen Shale and are indicative of bathyal deposition (Karp and others, 1972). The predominant megafossil is the small mud pectinid Propeamussum interradiatum

(Gabb), but fossil leaves and other organic materials including fish scales also have been found. Von Estroff (1930) believed the Kreyenhagen Shale of Reef

Ridge was deposited under marine conditions of normal salinity, at a depth of 92 m or more, which increased upsection. The assemblage of microfossils indicates 32

a slope to basin-floor environment of deposition with connections to the open ocean (Steinmeyer, 1972). Stewart (1946) believed that the absence or scarcity of other large invertebrates would further argue for deep-water deposition.

Hemipelagic shales also denote deep marine conditions (Reineck and Singh, 1980;

Reading, 1978). For additional information regarding the Kreyenhagen

Formation refer to von Estroff (1930), Cushman and Siegfus (1939), and Addicott (1972). LITHOSOMES AND DEPOSITIONAL ENVIRONMENTS

Seven lithosomes are recognized in the Avenal Sandstone. These include a fluvial lithosome, a sand-flat tidal-channel assemblage of tidal-channel conglomerate and tidal-channel sandstone lithosomes, and sand-flat, upper shoreface, lower shoreface, and transgressive lag lithosomes. The first five are present only northwest of the Garza Peak area, and the last two are present only southeast of the Garza Peak area.

A tidal-flat environment can be differentiated into supratidal (marsh), intertidal (sand flats), and subtidal zones (sand bars and channels) (Reineck and

Singh, 1980). Environmental subdivisions of the coastal zone as used herein are defined by Reineck and Singh (1980). The supratidal zone refers to the area above the mean high-water line. The intertidal zone is defined as the region between the mean high-water line and the spring-tide mean low-water line, and the subtidal zone is below the low-water line. The shoreface extends from the mean low-water level to the effective wave base at a water depth of less than 20 m. The transition zone denotes transitional sediment between the coastal sand and shelf mud. The upward limit of the transition zone is just below the normal wave base, where silt and clay settle down.

A sand-:flat subenvironment of a tidal flat environment can be regarded as a marginal-marine deposit, located adjacent to a land mass. In many modern examples, landward of the sand flat are marsh deposits. In the case of the

Avenal Sandstone, fluvial deposits were landward of the sand flat. Seaward of sand flats in modern settings are coastal sands or shoreface-like deposits (Reineck and Singh, 1980). Such was the situation during deposition of the

Avenal. Seaward from the shoreface deposits on modern coasts are transition

33 34

sediments represented by alternating coastal sands and more offshore clayey silt and silty clay (Reineck and Singh, 1980). This environment is not recognized in the Avenal Sandstone sequence and therefore is interpreted as having been eroded prior to the deposition of the overlying Kreyenhagen Formation.

Tidal flats occur in low-wave energy mesotidal (2-4 m) and macrotidal

(greater' than 4 m) settings where they dominate extensive stretches of shoreline, form within embayments, lagoons, or estuaries, or form on tidally influenced deltas (Hayes, 1975; Davis, 1978; Reading, 1980; Reineck and Singh, 1980;

Weimer and others, 1982). Tidal flats are featureless plains dissected by a network of tidal channels and creeks (Reading, 1980; Reineck and Singh, 1980).

Tidal channels supply water and sediment to the tidal flat (Weimer and others,

1982). During flood periods, tidal waters enter channels, overtop the channel banks and inundate the adjacent sand flats (Reading, 1978).

Most previous work or study of tidal-flat environments has been concentrated mainly on fine-grained (mud-dominated) tidal flats, with less work done on tidal channels and sand bodies (Davis, 1978).

FLUVIAL LITHOSOME

Fluvial description

Fluvial deposits crop out along the west flank of Reef Ridge from the

Garza Peak area northwest to Zapato Canyon (Fig. 3). These deposits unconformably overlie the Upper Cretaceous Panoche Formation. The only places that the basal unconformable contact is exposed is at Canoas Canyon and just north of Big Tar Canyon (Fig. 3). Fluvial deposits consist of pebble conglomerate (70%) and medium- to coarse-grained sandstone (30%). Color ranges from grayish orange (10 YR 7/4) to dark orangish gray (10 YR 6/6) on weathered and fresh surfaces. Deposits occur most commonly in the lower third 35

of the formation but locally are absent in Canoas and Arroyo Pinoso Canyons. In

Reese Canyon, deposits are 7 m thick and occur as a basal conglomerate. Conglomerate beds are lens shaped, range in thickness from 10 em to 1.5 m, averaging 20 em, and are laterally continuous from 50 em to 9 m (Figs. 16 and 17) Most of the clasts in the conglomerate are poorly sorted and matrix supported (75%) in medium- to coarse-grained sandstone. Clast-supported conglomerate (25%) is present locally. No imbrication, stratification, or grading were seen. The bases of conglomerate beds are generally erosional surfaces that display excellent scour-and-fill structure (Fig. 18). Some lower contacts, however, are gradational. Upper contacts with the overlying tidal-channel conglomerate lithosome are sharp.

Conglomerate clasts constitute 50% to 65% of the rock, range in size from granule to cobble, averaging pebble size, and are subrounded to well rounded and equant in shape. Most abundant clasts are pebbles of well rounded quartzite and chert. Less common clasts are pebbles of metavolcanic, sedimentary, and granitic rocks (Table 3). Quartzite clasts tend to be the largest, having maximum size of 15 em in diameter. Black chert pebbles are generally the smallest, averaging 1 em. Angular to subangular shale rip-up clasts, up to 12 em in length occur locally and are best exposed in Garza Canyon near the base of the Avenal (Fig. 17).

The sandstone matrix in the conglomerate is moderately sorted, medium-to coarse-grained, biotitic arkose (sample GC-2, Table 1). The matrix sandstone in the conglomerate also occurs in interbedded lenses. Beds range in thickness from a few centimeters to 2 m, averaging 30 em. They locally extend over 5 m laterally. The sandstone is predominantly structureless, but locally it is low angle, medium-scale, trough cross bedded, laminated, or burrowed. Contacts with conglomerate beds are sharp to gradational. 36

... '""' . .. ,.... - ": ' ~ ' "' ~

Figure 16. Fluvial lithosome with interbedded lenses of conglomerate and sandstone exposed at the base of the Garza Canyon section. Hammer is 33 em in length.

Figure 17. Fluvial lithosome with interbedded lenses of conglomerate, sandstone, and shale rip-up clasts exposed at the base of the Garza Canyon section. Hammer is 33 em in length. 37

Figure 18. Scour-and-fill erosional contact of the tidal-channel lag lithosorne into parallel laminated sand stone of the tidal-channel sandstone-fill lithosorne exposed in Zapato Canyon. Pencil is 17 ern in length.

Fluvial deposits locally contain abundant megafossils (!_.~. internal molds of unidentifiable articulated and broken bivalves). Scattered wood fragments are also present. About 0.5 km south of Zapato Canyon, Arnold (1910, USGS loc. 4615) found Ba.rbatia, Acanthocardia [=Cardium J , Corbula, Ostrea, Pitar fMeretrix ], Placunanomia, small-sized Venericardia, and Acteon in the upper portion of pebble conglomerate. Stewart (1946) reported the conglomerate in

Garza Canyon to contain Molopophorus, Terebra, Umpquaia, Calyptraea,

Neverita, Acila, Brachidontes, Crassatella, and Glycymeris. 38

Fluvial interpretation

The interbedded conglomerate and sandstone deposits of the Avenal are similar to river-channel deposits described by Reineck and Singh (1980). Fluvial transported gravels are generally channelized with scoured erosional bases and horizontal upper surfaces (Clifton, 1973; Miall, 1978; Reineck and Singh, 1980;

Cherven, 1983b) as observed in the Avenal exposures. The conglomerate and sandstone beds are lenticular, which is similar to stream or fluvial channel deposits described by Clifton (1973) and Miall (1978). Low-angle, medium-scale, trough crossbedding may be a characteristic structure of fluvial deposits

(Reineck and Singh, 1980; Cherven, 1983b). Cherven (1983b) described fluvial deposits of a delta-plain environment in the Sacramento Valley as containing discontinuous lenses or pods of mudstone rip-up clasts commonly at the base.

Shale rip-up clasts occur near the base in the Avenal. Because these fluvial deposits are below and interbedded with marginal-marine tidal-flat deposits, it is apparent that they represent the upper subaerial part of a tidal-dominated delta.

Some upper beds contain articulated marine bivalves, wood fragments, and burrows which suggest that the conglomerate locally was reworked by ocean waves where streams or rivers entered into a marginal sea.

SAND-FLAT TIDAL-CHANNEL DEPOSITS

Sand-flat tidal-channel deposits crop out along Reef Ridge northwest of the Garza Peak area (Fig. 3). These deposits are found near the base of the formation, overlying fluvial conglomerate where present, and scattered upward throughout mostly the lower half of the formation (Figs. 8 to 13). The sand-flat tidal-channel deposits are subdivided into two lithosomes: tidal-channel conglomerate (10%) and tidal-channel sandstone fill (90%). Each is described separately, but the two are interpreted as a single unit. 39

Tidal-channel conglomerate description

Tidal-channel conglomerate deposits are channelized pebble stringers and occur in all sections northwest of the Garza Peak area interbedded with fluvial, sand-flat, and tidal-channel sandstone-fill deposits. Color is grayish orange (10

YR 7 /4) to medium gray (N 4) on a weathered surface and grayish orange (10 YR

7 /4) to grayish black (N 2) on a fresh surface. Lens-shaped beds range in thickness from 2 to 15 em, averaging 4 em, and are laterally continuous from 30 em to 15 m (Fig. 19). Pebble stringers consist mostly of subrounded to well rounded chert and quartzite (Table 3), but in Garza, Reese, and Arroyo Pinoso

Canyons they consist of only black chert clasts. Quartzite clasts range in diameter from 1 to 4 em, averaging 2 em in thickness. Chert clasts range in diameter from 0.25 to 1.5 em, averaging 1 em. Best exposures of tidal-channel conglomerate are found in Garza, Arroyo Pinoso, and Za.pato Canyons (Figs. 9,

12, and 13). Basal contacts of the tidal-channel conglomerates are erosional, whereas upper contacts are gradational into overlying tidal-channel sandstone fill.

Tidal-channel sandstone-fill description

Tidal-channel sandstone-fill deposits are characterized by bidirectional, cross-bedded, parallel-laminated, ripple-laminated, convolute-bedded, fine grained sandstone, which locally contains beds with grading. Tidal-channel sandstone-fill deposits occur in all sections northwest of the Garza Peak area.

Where tidal-channel conglomerate is present, it grades upsection into tidal channel sandstone fill. In Canoas and Arroyo Pinoso Canyons (Figs. 10 and 12), tidal-channel sandstone occurs without associated conglomerate. Color is yellowish gray (5 Y 7 /2) to medium gray (N 5) to light olive gray (5 Y 6/1) on a weathered surface and yellowish gray (5 Y 7 /2) to light gray (N 7) to pale 40

Figure 19. Tidal-channel lag deposits range in thickness between 2 to 15 em thick interbedded with tidal-channel sandstone-fill deposits. yellowish brown (10 YR 6/2) on a fresh surface. Tidal-channel sandstone deposits range in thickness from 2 to 10 m, averaging 5 m, and are complexly interbedded with tidal-channel conglomerate and sand-flat deposits. Beds in the tidal-channel sandstone fill are primarily tabular and range in thickness from 5 em to 1.5 m, averaging 20 em.

The sandstone of the tidal-channel sandstone-fill deposits is a moderately to well-sorted, fine-grained, micaceous arkose (Table 1, Fig. 9). Bidirectional, medium- to large-scale, low- to high-angle, tabular cross beds are in the lower third of the formation (Fig. 20) and are preserved locally in scattered concretions (Fig. 21). Cross-bed sets range in thickness from 26 to 55 em.

Trough cross beds are found within small channels in Arroyo Pinoso and Zapato

Canyons, near the tops of the two sections (Figs. 12 and 13). Paleocurrent studies indicate both southwest and northeast current directions. Possible load 41

Figure 20. Bidirectional crossbedding of the tidal channel sandstone-fill lith osome. Pencil is 17 em long.

Figure 21. Crossbedding of the tidal-channel sandstone-fill lithosome preserved in concretions near the basal contact in Canoas Canyon. Knife is 8 em in length. 42

features are found on basal surfaces of these channels in Arroyo Pinoso Canyon.

Load features in the sandstone occur as irregular lobes, varying in shape from slight bulges to irregular protuberances. Parallel laminations range from 1 to 20 mm in thickness, averaging 6 mm. They are defined by a change in grain size from very fine- to fine-grained sandstone, as well as by hematite-limonite staining and organic debris. The ripple-laminated sandstone contains small-scale symmetrical current or wave ripples (measuring 6 em from crest to trough) in

Garza Canyon (Fig. 22). In Canoas Canyon, climbing-ripple trough cross lamination (measuring 4 em from crest to trough) is found (Fig. 23). Climbing- ripple lamination is delineated by layers of carbonaceous material forming laminae which have been truncated by successive layers of advancing sand deposits. Convolute bedding is found locally above rippled intervals. The

Figure 22. Asymmetrical ripples of the tidal-channel sandstone-fill lithesome exposed in Garza Canyon. Hammer is 33 em in length. 43 ' .

Figure 23. Climbing-ripple cross-lamination of the tidal-channel sandstone-fill lithosome exposed in Canoas Canyon. Knife is 8 em in length.

sandstone of the tidal-channel sandstone-fill deposits contains subangular- to angular-shaped, shale rip-up clasts. Shale rip-up clasts are present in a lens 6 em

wide and 4 m in length in Canoas Canyon (Fig. 10), 10 m above the base of the section. Beds with grading are rare and range from coarse grained at the bottom

to fine grained at the top. These beds are 32 to 40 em thick and up to 40 em in lateral exposure. Concretions of various shapes and sizes are hematite and/or limonite stained and are found scattered throughout the deposits. Concretionary lenses make up about 20% of the tidal-channel sandstone deposits and range in thickness from 10 em to 1 m.

Carbonaceous rna terial and wood fragments account for 1% to 2% of the tidal-channel sandstone fill and are more abundant in this lithosome than elsewhere in the formation. The carbonaceous material occurs in irregular, wavy 44

lenses that range in thickness from 0.1 to 4 em, averaging 1 em, and of variable

lengths. Wood fragments are most abundant in Garza Canyon, and range from a few centimeters to 16 em in length and 6 em in width. Megafossils are scarce

and are found in concretionary lenses. Those identified from Garza Canyon

(CSUN locality 768) are listed in Table 4.

Sand-flat tidal-channel interpretation

In a sand-flat tidal-channel environment, tidal-channel deposits typically

form by lateral filling of migrating tidal channels, a process similar to the filling

of meandering fluvial channels by point bars (Kanes, 1969; Reinson, 1979). Tidal

channel deposits have a high potential for preservation if the depth of the tidal

channel inlet is great enough so that the basal portions of deposit extend below

low-tide level. If so, the basal portions will be protected from shoreface erosion

during transgressive conditions, as pointed out by Reinson (1979) and Weimer and

others (1982). This must have been the case for the sand-flat tidal-channel

deposits of the Avenal Sandstone. Tidal channels in modern sand-flat tidal

environments have sharp erosional basal and lateral contacts and gravelly lag

deposits along the bottoms of the channels (Hayes and Kana, 1983). Near the

bases of the channels, coarser material, such as polymictic pebbles, cobbles,

shells, and plant debris, has been winnowed and is concentrated as channel lag or

conglomeratic lag deposits (Kanes, 1969; Johnson and Friedman, 1969; Reinson,

1979; Reineck and Singh, 1980; Hayes and Kana, 1983). Lag conglomerates represent residual concentrations and accumulate as discontinuous lenticular

patches in deeper parts of channels. Lag conglomerates rapidly become covered by cross-bedded to parallel- and/or ripple-laminated sandstone (Reading, 1978).

Convolute bedding, slump structures, and load features are also found (Reineck and Singh, 1980). These features occur in the Avenal Sandstone. Grain size 45

decreases upward into overlying bidirectional, cross-bedded, fine- to medium

grained sands. The bidirectional, cross-bedded sand in modern tidal channels is, · perhaps, one of the most diagnostic features of sand-flat tidal channels. The

bidirectional, low- to high-angle cross bedding is the result of alternating ebb

and flood flow (Reineck and Singh, 1980; McCubbin, 1982; Weimer and others,

1982; Heron, pers. commun.). Bidirectional cross bedding is common in the sand

flat tidal-channel deposits of the Avenal Sandstone. Climbing-ripple lamination,

like that seen in the Avenal, forms today only under relatively weak

hydrodynamic conditions and where a very large amount of sand is available for

deposition (McKee, 1966). According to McKee (1966), climbing-ripple

lamination commonly is associated with a limited amount of trough- and planar

cross stratification and with convoluted bedding. This is also observed in the

Avenal. The local occurrences of graded beds could be related to short-lived,

storm-wave pulses similar to those observed by Hayes (1967) for modern tidal

environments.

The scattered pebbles, shale rip-up clasts, and wood fragments are

probably related to a temporary local increase in the influx of land-derived

sediment. Wood fragments are common in modern sand-flat channels and usually

accumulate in troughs after flood current or storm activity (MacKenzie, 1975;

Moslow, 1980; Reineck and Singh, 1980; Weimer and others, 1982). The

relatively abundant wood fragments in the Avenal Sandstone tidal-channel

deposits are interpreted to have accumulated in the same manner, as did sparse

mollusk remains. The megafossils in the tidal-channel deposits of the Avenal are

mostly epifaunal forms. Locally, the substrate must have been shelly or rocky

hardground in order for these animals to attach themselves. Calyptraea,

Barbatia, and Brachidontes are especially indicative of such areas. 46

SAND-FLAT LITHOSOME

Sand-flat description The sand-flat lithosome is exposed in all sections northwest of the Garza

Peak area. This lithosome is complexly interbedded with tidal-channel deposits

(Figs. 9 to 13). Deposits are found scattered throughout the lower two-thirds of the formation but are also found higher in the section in Arroyo Pinoso and Zapato Canyons (Figs. 12 and 13). Color is light gray (N 7) to yellowish gray (5 Y

7 /2) on a weathered surface and light gray (N 7) to pale yellowish orange (10 YR

8/6) on a fresh surface. Beds are tabular and range in thickness from 30 em to 1 m, averaging 50 em. Except for the burrows described below and some parallel laminations in Garza Canyon, the beds are internally structureless. Upper and lower contacts are irregular and sharp to gradational. Solitary spheroidal hematite-limonite-stained concretions are found scattered throughout the lithosome.

The sand-flat lithosome is characterized by burrowed (up to 50%), moderately to well-sorted, fine-grained, micaceous arkose (Table 1). Thin sections show the sandstone to be plant- and clay-bearing, calcitic, and phosphatic. Bedding surfaces of the sand-flat deposits are marked by vertical and horizontal Ophiomorpha and U-shaped burrows, with vertical predominant.

Well preserved Ophiomorpha burrows range from 0.5 to 8 em in diameter and 3 to 50 em in length, averaging 1 em by 10 em. Burrows may be solitary, branching-maze, or boxwork patterns. The largest burrows are found in Zapato

Canyon (Fig. 24). Burrow forms are enhanced by hematite and/or limonite staining.

Megafossils are rare in the sand-flat lithosome and occur in Canoas Canyon in a concretionary lens in the middle of the section (Fig. 10), but they were not collected due to their extreme induration. 47

. ( _- ~'· ·_ ·' - l )j . . wi . . 'i . ~ J !'.

Figure 24. Boxwork pattern of Ophiomorpha burrows characteristic of the sandflat lithosome exposed in Zapato Canyon near the top of the section. Hammer is 15 em in length.

Sand-flat interpretation

The burrowed sandstone deposits, interbedded with tidal-channel deposits, are interpreted as having formed within a sand-flat environment. Sand flats

(also referred to as sandy tidal flats) occupy the intertidal area and are subjected to currents and waves (McCants, 1982; Weimer and others, 1982). Modern and ancient sand flats are typically characterized by very well to moderately sorted, very fine- to medium-grained sand (MacKenzie, 1975; Reinson, 1979; Reineck and Singh, 1980; McCants, 1982; Weimer and others, 1982). Modern sand-flat deposits can be slightly burrowed to completely bioturbated (Reineck and Singh, 48

1980; McCants, 1982; Weimer and others, 1983), or display sedimentary structures. Textures and structures of a sand flat are controlled primarily by the energy of the environment, such as wave and current energy (Howard and others,

1972; Greer, 1975), and sediment supply (Hayes and Kana, 1983). Therefore, sand-flat deposits are diverse depending on the conditions that exist at the time of deposition. The sand-flat lithosome of the Avenal Sandstone is burrowed and predominantly structureless.

Howard and others (1972) describe areas of up to 50% bioturbation as forming in the shoal or interchannel areas, where lesser amounts of bioturbation allow one to recognize specific burrow forms, as is the case for the Avenal.

Non-bioturbated areas found in a normally burrowed sequence commonly consist of laminated sands (Howard and others, 1972), which may be the explanation for the parallel-laminated interval in the upper third of the formation in Garza

Canyon. Greer (1975) found that parallel lamination is present in shoal areas on a sand-dominated tidal flat of the Georgia coast. Upper flow regime conditions created by breaking waves, produce laminated sands (Greer, 1975).

Megafossil lenses in the sand-flat deposits of the Avenal Sandstone are interpreted as storm-generated deposits. Shell debris commonly is reported in modern sand flats where it accumulates after flood current or storm activity

(McKenzie, 1975; Moslow, 1980; Reineck and Singh, 1980; Weimer and others,

1982).

UPPER SHOREFACE LITHOSOME

Upper shoreface description

Upper shoreface deposits occur in most sections in the northern portion of the study area (northwest of the Garza Peak area), except in Arroyo Pinoso and

Zapato Canyons, and are found mostly in the upper fourth of the formation. 49

Upper shoreface deposits occur stratigraphically below the bathyal Kreyenhagen

Formation and above the sand-flat deposits. In general, the abundance of burrowing increases upsection in the Avenal Sandstone. Upper shoreface deposits grade upward from the underlying sand-flat lithosome. The upper shoreface is defined by an increase in burrowing to between 50% and 90%, as compared to the sand flat which contains up to 50% burrowing and is complexly interbedded with tidal-channel deposits.

The upper shoreface lithosome consists mainly of fine-grained, bioturbated (50% to 90%) sandstone that locally contains a fossiliferous concretionary lens in

Canoas Canyon (Fig. 25). Color is grayish orange (10 YR 7/4) to light gray (N 7) on a weathered surface and pale yellowish orange (10 YR 8/6) to yellowish gray

(5 Y 7/2) on a fresh surface. The sandstone beds are tabular and range from 10 em to 1.5 m in thickness, averaging 50 em. Upper and lower contacts are sharp.

In Garza Canyon, the sandstone is locally parallel laminated. Laminations range from 1 to 20 mm in thickness, averaging 8 mm. Bioturbation is recognized by a mottled appearance. Carbonate cementation and local diagenetic alteration of unstable grains to hematite and limonite enhance the presence of remnant burrows, of which Ophiomorpha is most common. The lined burrows are horizontal and vertical, with vertical predominant. Burrow diameters average 1 em. Burrow lengths are indeterminant due to overprinting of burrows. Solitary spheroidal concretions of various sizes are found scattered throughout this lithosome.

Upper shoreface interpretation

The burrowed (50% to 90%), moderately to well-sorted, fine-grained sandstone is interpreted as having formed in an upper shoreface environment. It is not found interbedded with tidal-channel deposits. 50 ' .

Figure 25. Bioturbated fine-grained sandstone of the upper shoreface lithosome exposed in Canoas Canyon. Knife is 8 em in length. 51

Characteristics of upper shoreface deposits are determined largely by wave energy, tidal range, and biogenic processes (Moslow, 1980). In a high-wave energy situation, primary structures predominate over biogenic structures and various sedimentary structures occur. In low-wave energy settings, biogenic activity is dominant and sediments tend to be homogenous, poorly sorted, and structureless. Areas of intermediate- to low-wave energy are characterized by bioturbated sands alternating with parallel-laminated, storm-deposited sands

(Howard and Reineck, 1972; Moslow, 1980).

Modern and ancient examples of upper shoreface deposits are characterized by bioturbated sandstone with alternating parallel-laminated deposits (Howard, 1971; Howard and Reineck, 1972; Howard and others, 1972;

Goldring and Bridges, 1973; Kumar and Sanders, 1976; Squires, 1981, 1983). In such cases, the laminated sand represents storm-influenced stratification, and the biogenic reworking is the interstorm activity. Howard and Reineck (1972) point out that in all areas, from high -to low-wave energy, there is a seaward fining of sediment, and in areas of low- to intermediate-wave energy, bioturbation increases in the offshore direction.

Bioturbation within the Avenal Sandstone, recognized vertically as well as laterally in measured sections, increases in the offshore direction, and the rock is slightly finer grained upsection in the southeast (Big Tar East section).

Parallel lamination occurs only in Garza Canyon. Therefore, the Avenal upper shoreface deposits probably accumulated under low-wave energy conditions, with a low frequency of storm activity and/or low sedimentation rates. Shell fragments in the upper shoreface deposits are sparse and concentrated in lenses, which is similar to the shell deposits described as storm deposits or storm lags off the coast of Padre Island (Hayes, 1967) and Long Island 52

(Kumar and Sanders, 1976).

Ophiomorpha burrows are abundant as vertical shafts or horizontal mazes in the upper shoreface {Chamberlain, 1978), as they are in the Avenal upper

shoreface deposits. In areas where the substrate is 50% to 90% bioturbated, it is

still possible to recognize biogenic activities of some specific organisms, but

· masking commonly occurs because of abundant "overprinting". Reworking of

sediments in these areas is so thorough that a mottled texture is preserved

(Howard and others, 1972). This same mottled texture is recognized in the

Avenal upper shoreface deposits.

LOWER SHOREFACE LITHOSOME

Lower shoreface description

The lower shoreface lithosome occurs only in the southern portion of the

study area, from Garza Peak area southeastward. Northwest of the Garza Peak

area, this lithosome grades laterally into upper shoreface deposits. In the Big

Tar Canyon area, the lower shoreface lithosome reaches a maximum of 89 m in

thickness. Exposures of the lithosome are poor due to dense grass cover. The

basal contact with the underlying Upper Cretaceous Panoche Formation is poorly

exposed. The upper contact with the overlying Kreyenhagen Formation is sharp.

This lithosome consists of structureless (90% to 100% bioturbated) and

fossiliferous, moderately sorted, silty to fine-grained sandstone. Color is grayish

orange (10 YR 7 /4) to dark yellowish orange (10 YR 6/6) on a weathered surface

and light gray (N 7) to grayish orange (10 YR 7/4) on a fresh surface.

Petrographic analysis of thin sections (Table 1) indicates that the sandstone is

locally glauconitic, phosphatic, plant bearing, and foraminiferal bearing.

Sedimentary structures are rare, but locally, near the top of the lithosome,

parallel laminations are present and range from 1 to 20 mm in thickness, 53

averaging 10 mm. Grain size of the lithosome decreases upsection. Near the

contact with the overlying shale of the Kreyenhagen, the silt content' of the lithosome increases, but no interfingering of sandstone and shale was observed.

The lower shoreface lithosome locally contains abundant body fossils in

concretionary lenses. These lenses average a meter thick and can be traced l.B.terally for distances up to 0.5 km. They are primarily in the lower portion of

the lithosome and are scarcer in the increasingly more silty beds upsection. The megafauna, from 8 localities (Fig. 3), consists mostly of gastropods and

bivalves, with gastropods the most diverse (Table 4). Minor constituents are

scaphopods, large foraminifers (discocyclinids), calcareous worm tubes, solitary

and colonial corals, crab claws, mammal? bones, and carbonized wood fragments.

Collecting for this study was not exhaustive, but the fauna collected is representative of the lithosome. Nearly every obvious exposure of the lithosome was searched for megafossils.

There is much variability in the taxonomic composition of the fossiliferous deposits. At locality 764, 41 species were found whereas at localities 760, 766, and 769 only a few species were found. There is no consistent vertical stratigraphic change in the taxonomic composition of the megafauna. Species that characterize the lower shoreface lithosome are Ectinochilus (Macilentos) macilentus, Turritella aedificata, Turritella buwaldana, and Pitar

(Lamelliconcha) joaquinensis. In addition, in the southern part of the area,

Turritella andersoni lawsoni, Rotularia tejonense, and Pseudophragmina (Proporocyclina) clarki can be locally very abundant.

Megafossils in the lithosome do not appear to be abraded and some show preservation of delicate shell features, such as outer lips, ribs, and nodes. At locality 764, a specimen of the minute gastropod Marginella (Leptegouana ?) hulini was found with the zig-zag color pattern intact. In addition, there are 54

growth series of Calyptraea diegoana and Cylichnina tantilla. Also at this

locality, articulated specimens of the small bivalve Nuculana (Saccella) chaneyi were found.

Lower shoreface interpretation

This lithosome is interpreted to have formed in a lower shoreface

environment. The main sedimentological evidences are gradation northwardly

into upper shoreface deposits, the predominance of silty fine-grained sandstone, and the nearly total lack of physical sedimentary structures. According to

Howard and others (1972), in an area of 90% to 100% bioturbation there is little indication of any specific burrows. Rather the sediment is completely homogenized and looks structureless. This situation is characteristic of the lower shoreface deposits of the Avenal. Depth and occurrence of the lower shoreface off modern coasts is dependent upon wave energy and availability of both sand and finer grained material (Howard and Reineck, 1972). The lower the energy of the coast, the shallower the lower depth limit of the lower shoreface.

On the average, the lower depth limit is about 10 m, but it can be as much as 20 m depth (Howard and Reineck, 1972; Reineck and Singh, 1980). Modern lower shoreface-transition deposits are subject to extensive reworking by bottom dwelling and feeding animals, and, in the process, nearly all traces of primary lamination are destroyed {Moslow, 1980; Reineck and Singh, 1980), as has probably happened in nearly every exposure of this lithosome.

'The presence of shallow-marine megafossils in lenses in the lithosome is supportive also of a lower shoreface environment. Post-mortem transport was most likely due to storm-related? wave action, but the distance of transport was not great as the shelly remains are relatively unworn. Articulated bivalves are all very small and they may have been transported while alive. Brenner and 55

Davies (1973) have discussed how high-amplitude swells over the sediment-water interface can produce concentrations of shells. Many of the taxa that have been reported in this present study (Table 2), as well as others reported by Arnold (1910), Vokes (1939), and Stewart (1946), for this part of the Avenal Formation are ones that Durham (1950) considered particularly characteristic of modern tropical waters (200C or warmer). These are the gastropods Akera, Ancilla[=Ancillaria], Architectonica, Conus, Cypraea,

Eocithara [:=Harpa ], Ectinochilos [=Rim ella], Eocernina, Lyria, Nerita, Olivella,

Paraseraphs [=Terebellurrij, Pseudoliva, Terebra, Turritella, Voluta, and

Xenophora; and the bivalves Corbula, Crassatella [=Crassatellites], Macrocallista,

Miltha, Pitar, Pinna, Pteria, Spondylus, and large Venericardia. Except for

Eocithara, Eocernia, Ectinochilus, Paraseraphs, Crassatella, and Venericardia, these genera are extant and most frequently occur in marine waters less than 50 m depth (Morris, 1966; Abbott, 1974; Keen, 1971; Lindner, 1978; Saul, 1983b;

Squires, in press). Saul (1983a) also reported that large Venericardia (like those found in this lithosome) indicate nearshore, shallow-water conditions. The megascopic discocyclinid foraminifer Pseudophragmina, which is abundant in the southern part of the study area, also lived in shallow water (below tide level to perhaps 100m) (Berthiaume, 1938; Vaughan, 1945; Durham, 1950).

It is also significant to add that Vokes (1939) and Durham (1950) considered the Eocene Reef Ridge megafauna <.!_.~., the lower shoreface lithosome of the

Avenal Sandstone) to have lived in warm, shallow-water conditions (probably less than 50 m depth). West Coast Eocene megafaunas, furthermore, have long been

TRANSGRESSIVE LAG LITHOSOME

Transgressive Lag Description

The transgressive lag lithosome is recognized only in the southern portion 56

of the study area1 from Big Tar Canyon southeast to the Sulphur Spring area assigned to tropical or subtropical environments (Arnold, 1910; Dickerson, 1913, 1917; Smith, 1919; Clark and Vokes, 1936; Berthiaume, 1938; Vokes, 1940;

Durham, 1950; Addicott, 1970; Armentrout, 1975) (Figs. 3 and 4). Exposures are scarce due to dense grass cover and always are at the base of the formation.

This lithosome has a maximum thickness of 6 em and grades upward into lower shoreface deposits. The transgressive lag is characterized by a pebbly, fossiliferous sandstone. Deposits contain 45% pebbles and shell fragments and

55% fine- to medium-grained sandstone.

'Ii'ansgressive Lag Interpretation

The sparse, thin conglomeratic sandstone lenses exposed between Big Tar

Canyon and Big Tar Canyon East (southern portion of study area) are interpreted as transgressive-lag deposits. 'Ii'ansgressive lag has been described by Swift

(1975, 1976) as the product of shoreline advance along transgressive coastlines.

'Ii'ansgressive lag deposits are moderately sorted, fine-grained sandstones associated with gravel lag and fragmented shell debris (Swift, 1968). According to Clifton (1981), a basal conglomerate typically consists of scattered pebbles in a sandstone matrix, but some beds are composed predominantly of pebbles, cobbles, and scattered shell fragments. AVENAlrKREYENHAGEN UNCONFORMITY

A normal sequence of depositional environments that would occur in a stratigraphic column that represents a transgressive fluvial and tidal sand-flat shoreline would start with fluvial deposits at the base and proceed through interbedded sand-flat and tidal-channel deposits, shoreface deposits, transition zone deposits, and finally offshore deposits. Study of Figures 8 to 13 shows that this sequence is never complete in the Avenal Sandstone. The Kreyenhagen

Formation represents offshore deposits which are present at the top of each of the measured sections. In the southern four sections, however, the transition zone deposits are missing and in the northern two sections both the shoreface and transition zone deposits are missing. Furthermore, the Kreyenhagen

Formation immediately overlying the shallow-marine rocks of the Avenal

Sandstone contains bathyal foraminifers (Green and Associates, pers. commun.).

In Garza Canyon, the Canoas turbidite member of the Kreyenhagen Formation lies immediately on top of the Avenal Sandstone. Finally, the contact between the Avenal and the Kreyenhagen is an abrupt and sharp change from sandstone to shale. The above facts indicate that the Avenal-Kreyenhagen contact is a very slightly angular unconformity, rather than a conformable contact as has previously been assumed.

The implication of this hypothesis is that the area was slightly uplifted during the early medial Eocene and part of the nearshore sequence of deposits was eroded away, more so to the north than to the south. Following erosion, the area rapidly subsided to bathyal depths where the Kreyenhagen Formation was deposited without any evidence of the nearshore deposits of the last transgression being preserved. Both the uplift and subsidence events lasted only

57 58

a short time, shorter than the length of a fossil zone, so that there is no paleontologic evidence for an unconformity. PROVENANCE

According to Reed (1924), all the clastic Tertiary formations of the Reef

Ridge area derived sediment mostly from Cretaceous strata to the west, and in part from the Franciscan metamorphic complex to the west. Nilsen and Clarke

(1975), however, believed that the main source areas of lower Tertiary deposits in the Reef Ridge area could have been located both westward in the Salinian block and eastward in the Sierra Nevada, with Franciscian rocks in the Mount

Diablo area constituting a minor source. They also maintained that distinguishing sandstones and conglomerates derived from eastern sources from those derived from western source areas is difficult because of the almost ubiquitous presence of granitic, volcanic, and quartzitic clasts. Because the

Avenal Sandstone lies unconformably on the Panoche Formation, it is possible that the Panoche was eroding within the Avenal source area.

Petrographic studies reveal that the Avenal Sandstone consists of submature to mature arkose (Table 1, Fig. 14). Folk (1980) states that a submature arkose is indicative of a mild tectonic setting during sedimentation, whereas a mature arkose is indicative of stable conditions.

Heavy minerals (Table 2) of the Avenal Sandstone indicate a mixed source containing granitic, volcanic, and low- to high-rank metmorphic rocks. The durable rounded clasts of the conglomerate beds (Table 3) indicate a similar mixed source of granitic, sedimentary, volcanic and high-rank metamorphic rocks. The same suite. of clasts, however, occurs in the conglomerate beds of the underlying Cretaceous and Jurassic rocks (Great Valley Sequence) of the Panoche and Franciscan Formations, respectively. The roundness of durable clasts

(quartzite and volcanic) in the Avenal and the roundness of glauconite, some of

59 60

the garnet, tourmaline, and zircon grains could indicate reworking of these older

Panoche and Franciscan rocks. A sedimentary source is also suggested by the presence of chert, jasper, chalcedony, claystone, and sandstone clasts.

Sandstone from the underlying Panoche Formation was examined and found to be also arkosic in composition (Table 1, Fig. 14). Biotite grains are larger and more abundant in the Cretaceous samples, as would be expected if the Panoche

Formation was a source for the Avenal Sandstone. Rounded glauconite grains are present in the Cretaceous samples as well as in the Avenal, which further suggests a reworked Cretaceous source. Feldspar grains are fresher and have undergone less weathering in the Panoche Formation, as compared to the Avenal feldspars. Erosion and transport of the Cretaceous feldspars could account for the more weathered and corroded nature of feldspars of the Avenal, if the

Cretaceous was in fact the source. The Jurassic Franciscan Complex structurally underlies the Cretaceous and also may have provided sediment for the Avenal, especially chert clasts.

Marsh (1960) found reworked Cretaceous foraminifers in shale interbeds in the lower part of the Avenal Sandstone in the Orchard Peak area, 4 km southwest of the study area, which also indicate some Cretaceous reworking.

Frames (pers. commun.) described the Cretaceous through Eocene sequence in the Kettleman Hills of the San Joaquin Valley, east of the Avenal outcrops, as one of continuous deposition. This means that in the earliest Eocene, while the

Reef Ridge area was eroding to form the unconformity at the base of the

Avenal, a depositional marine basin existed to the east (Berggren and Aubert,

1983). This being the case, it seems unlikely that sediment from the Sierra

Nevada could have crossed the "center of this basin and moved uphill" into the Reef Ridge area during the Avenal transgression. The most likely provenance, 61

therefore, is the Mesozoic sedimentary rocks to the west of the present outcrops. PALEOGEOGRAPHY

The paleogeographic reconstruction of the late early through early medial

Eocene age Avenal Sandstone is based on sedimentologic and paleontologic evidence from surface exposures and subsurface information. The contact between the Eocene Avenal and the underlying Upper Cretaceous Panoche

Formation is an angular unconformity. As noted above, the depositional sequence, as studied in the subsurface east of the study area in Kettleman Hills oil field, contains a complete section of strata and shows no hiatuses paleontologically from the Cretaceous through the Eocene. Therefore, a localized paleo-high must have existed west of Kettleman Hills sometime between the Late Cretaceous and the late early Eocene. During this time, a period of erosion or nondeposition created an Upper Cretaceous through lower

Eocene hiatus. Regional subsidence beginning in the late early Eocene resulted in westward transgression and subsequent deposition of the Avenal transgressive sequence described above.

In the Reef Ridge area, the paleo-high contained a topographic valley with eastward-flowing fluvial influences that carried sediment to a north-south trending marginal sea. Slope of the river valley was gentle north of the Garza

Peak area, and as the sea transgressed a tidal-dominated delta and sand-flat deposit accumulated (Fig. 26). The sand flat with an extensive tidal-channel assemblage graded seaward into shoreface deposits. The coastline surrounding the tidal-dominated delta was probably irregular and rocky, and in areas such as southeast of the Garza Peak area, formed an above sea-level abutment so that

62 SANDFLAT- TIDAL u.-.-ER LOWER TRANSITION NW FLUVIAL CHANNEL SHOREFACE SHOREFACE ZONE (removed everrwhere .rM••••I In the etudr area br pre Krerenhaten eroelon ) LOW TIDR

l ·' _,/ .'.,,·· ,,.·· ...... / ..

...... /

SE Figure 26. Paleogeography during deposition of the Avenal Sandstone.

"'w 64

deposition could not take place. The shoreline probably was oriented in a northwest-southeasterly direction. In early medial Eocene time, the sea transgressed further westward, bringing shoreface deposition to the Reef Ridge area. As the sea became deeper, the rocky headland in the area southeast of Garza Peak was submerged and wave action was reduced sufficiently to allow deposition of lower shoreface sediment both there and throughout the region to the northwest. Intermittent storms reworked body fossils into lenticular deposits in the lower shoreface environment.

Subsequently, uplift to the north brought erosion of all shoreface deposits in the Arroyo Pinoso and Za.pato Canyon areas and erosion of lower shoreface deposits in Reese Canyon and Garza Canyon areas. Any deeper water deposits in the Avenal also were removed at this time. The Kreyenhagen bathyal shale and its associated Canoas sandstone turbidite member were deposited in very slight angular unconformity over the Avenal when rapid subsidence was renewed. REFERENCES

Abbott, R. T., 1974, American seashells (2d ed.): New York, Van Nostrand Reinhold Company, 663 p. Addicott, w. 0., 1970, Tertiary paleoclimatic trends in the San Joaquin Basin, California: U. S. Geological Survey Professional Paper 644-D, 19 p.

1972, Biostratigraphy and correlation of Tertiary sandstones at Big Tar Canyon, Reef Ridge, California, in Rennie, E. W., Jr., ed., Guidebook: geology and oil fields, west side central San Joaquin Valley: American Association of Petroleum Geologists, Society of Exploration Geophysicists, Society of Economic Paleontologists and Mineralogists, Pacific Sections, 47th Annual Meeting, p. 65-69.

Armentrout, J. M., 1975, Molluscan biostratigraphy of the Lincoln Creek Formation, southwest Washington, in Weaver, D. E., Hornaday, G. R., and Tipton, Ann, eds., Future energy horizons of the Pacific Coast: Paleogene symposium and selected technical papers: American Association of Petroleum Geologists, Society of Economic Paleontologists and Mineralogists, and Society of Economic Geologists, Pacific Sections, Annual Meeting, p. 14-28.

Anderson, F. M., 1905, A stratigraphic study in the Mount Diablo Range of California: California Academy of Sciences Proceedings, 3d. series, v. 2, p. 155-248. Anderson, F. M., and Pack, R. w., 1915, Geology and oil resources of the west border of the San Joaquin Valley, north of Coalinga, California: United States Geological Survey Bulletin 603, 220 p.

Anderson, J. Q., 1972, Cretaceous subdivisions of the Coalinga District, Fresno County, California, in Steinert, R. E., Cretaceous of the Coalinga area: Society of Economic-Paleontologists and Mineralogists, Pacific Section, Fall Field Trip Guidebook, p. 11-18.

Arnold, Ralph, 1910, Paleontology of the Coalinga district, Fresno and Kings Counties, California: U. S. Geological Survey Bulletin 396, 173 p.

Arnold, Ralph and Anderson, Robert, 1908, Preliminary report on the Coalinga oil district, Fresno and Kings Counties, California: u. S. Geological Survey Bulletin 357, 142 p.

1910, Geology and oil resources of the Coalinga district, California: U. S. Geological Survey Bulletin 398, 354 p.

Berggren, W. A., and Aubert, J., 1983, Paleogene benthic foraminiferal biostratigraphy and paleobathymetry of the central ranges of California,

65 66

in Brabb, E. E., ed., Studies in stratigraphy of the California Coast Ranges: u. S. Geological Survey Professional Paper 1213, p. 21. Berthiaume, S. A., 1938, Orbitoids from the Crescent Formation (Eocene} of Washington: Journal of Paleontology, v. 12, no. 5, p. 494-497.

Bodden, W. R., III, 1983, Depositional environments of the Eocene Domengine Formation outcrop on the north side of Mt. Diablo, California, in Cherven, V. B., and Graham, S. A., eds., Geology and sedimentology of southwestern Sacramento Basin and East Bay Hills: Society of Economic Paleontologists and Mineralogists, Pacific Section, Field Trip Guidebook, p. 43-57.

Brenner, R. L., and Davies, D. K., 1973, Storm-generated coquinoid sandstone: genesis of high-energy marine sediments from the Upper Jurassic of Wyoming and Montana: Geological Society of America Bulletin, v. 84, p. 1685-1698.

Bukry, D., 1973, Low-latitude coccolith biostratigraphic zonation, in Edgar, N. T., and others, Initial reports of the deep sea drilling project: v. XII, Washington, D.C., U.S. Government Printing Office, p. 685-703.

Chamberlain, C. K., 1978, Recognition of trace fossils, in Basan, P. B., ed., Trace fossil concepts: Society of Economic Paleontologists and Mineralogists, Short Course No. 5, p. 119-139.

Cherven, V. B., 1983a, Stratigraphy, facies, and depositional provinces of the middle Eocene Domengine Formation, southern Sacramento Basin: in Cherven, V. B., and Graham, S. A., eds., Geology and sedimentology of southwestern Sacramento Basin and East Bay Hills: Society of Economic Paleontologists and Mineralogists, Pacific Section, Field Trip Guidebook, p. 59-72.

·--- 1983b, A delta-slope submarine fan model for Maestrichtian part of Great Valley sequence, Sacramento and San Joaquin Basins, California: American Association of Petroleum Geologists Bulletin, v. 67, no. 5, p. 772-816.

Clark, B. L., 1935, Tectonics of the Mt. Diablo and Coalinga areas, middle Coast Ranges: Geological Society of America Bulletin, v. 46, p. 1025- 1100.

Clark, B. L., and Vokes, H. E., 1936, Summary of marine Eocene sequence of western North America: Geological Society of America Bulletin, v. 47, no. 6, p. 851-878, 2 pls., 3 figs.

Clifton, H. E., 1973, Pebble segregation and bed lenticularity in wave-worked verses alluvial gravel: Sedimentology, v. 20, p. 173-187.

1981, Progradational sequences in Miocene shoreline deposits, southeastern Caliente Range, California: Journal of Sedimentary Petrology, v. 51, no. 1, p. 165-184. 67

Clifton, H. E., 1981, Progradational sequences in Miocene shoreline deposits, southeastern Caliente Range, California: Journal of Sedimentary Petrology, v. 51, no. 1, p. 165-184. Coleman, J. M., and Prior, D. B., 1982, Deltaic environments of deposition, in Scholle, P. A., and Spearing, Darwin, eds., Sandstone depositional environments: American Association of Petroleum Geologists Memoir 31, p. 139-178. Crume, R. w., 1940, Foraminiferal faunule from the Avenal Sandstone (middle Eocene) of Reef Ridge, California (abstract): Geological Society of America Bulletin 51, 1982.

Cushman, J. A., and Siegfus, S. S., 1935, New species of Foraminifera from the Kreyenhagen shale of Fresno County, California: Cushman Laboratory Foraminifera Research Contributions, v. 11, p. 90-95.

1939, Some new and interesting Foraminifera from the Kreyenhagen shale of California: Cushman Laboratory of Foraminifera Research Contributions, v. 15, pt. 2, p. 22-33.

Davis, R. A. Jr., 1978, Beach and nearshore zone, in Davis, R. A., Jr., ed., Coastal sedimentary environments: New York,-Springer-Verlag, p. 101- 169. Dibblee, T. w., Jr., 1971-1974, Geologic mapping, Coalinga area and vicinity: U. S. Geological Survey, Open-file report, 17 sheets, index map.

Dickerson, R. E., 1913, Fauna of the Eocene at Marysville Buttes, California: University of California Publications in Geological Sciences, v. 7, no. 12, p. 257-298.

1917, Climatic zones of Martinez Eocene time: California Academy of Sciences Proceedings, 4th series, v. 7, p. 193-196. Durham, J. w., 1950, Cenozoic marine climates of the Pacific Coast: Geological Society of America Bulletin 61, p. 1243-1264.

Folk, R. L., 1980, Petrology of sedimentary rocks: Austin, Hemphill Publishing Company, 184 p. Foss, c. D., 1972, A note on the fluid level traps in the San Joaquin Valley, in Rennie, E. W., Jr., ed., Guidebook: geology and oil fields, west side central San Joaquin Valley: American Association of Petroleum Geologists, Society of Exploration Geophysicists, Society of Economic Paleontologists and Mineralogists, Pacific Sections, 47th Annual Meeting, p. 15-39.

Fowkes, E. J., 1982, An educational guidebook to the geological resources of the Coalinga district, California: Shannon Publications, Coalinga, p. 260. 68

Galloway, J., 1943, Kettleman Hills oil fields, in Geologic formations and economic development of the oil and gas fields of California: Part 'Three, Descriptions of individual oil and gas fields: Part Four, Glossaries, bibliography, and index: State of California Department of Natural Resources Division of Mines, Bulletin No. 118, p. 491-493.

Gester, G. c., and Galloway, John, 1933, Geology of Kettleman Hills oil field, California: American Association of Petroleum Geologists Bulletin, v. 17, p. 1161-1193.

Givens, c. R., 197 4, Eocene molluscan biostratigraphy of the Pine Mountain area, Ventura County, California: University of California Publications in Geological Sciences, University of California Press, v. 109, p. 1-107, 11 pls.

Givens, c. R., and Kennedy, M. P., 1979, Eocene molluscan stages and their correlation, San Diego area, California, in P.L. Abbott, ed., Eocene depositional systems, San Diego: Society ofEconomic Paleontologists and Mineralogists, Field Trip Guide, Geological Society of America Annual Meeting, p. 81-95.

Goddard, E. N., Compiler, 1980, Rock color chart: Boulder, Colorado, Geological Society of America, 8 p.

Goldring, R., and Bridges, P., 1973, Sublittoral sheet sandstones: Journal of Sedimentary Petrology, v. 43, p. 736-747.

Goudkoff, P. P., 1934, Subsurface stratigraphy of Kettleman Hills oil field, California: American Association of Petroleum Geologists Bulletin, v. 18, p. 435-475.

Greer, s. A., 1975, Estuaries of the Georgia Coast, U.S.A., sedimentology and biology. III. Sandbody geometry and sedimentary facies at the estuary marine transition zone, Ossabaw Sound, Georgia: a stratigraphic model: Senckenbergiana Maritima, v, 7, p. 105-135.

Hayes, M. 0., 1967, Hurricanes as geological agents, south Texas coast: American Association of Petroleum Geologists Bulletin, v. 51, p. 937-942.

Hayes, M. 0., 1975, Morphology of sand accumulation in estuaries: an introduction to the symposium, in L. E. Cronin, ed., Estuarine Research, Vol. 2, Academic Press, New York, N.Y., p. 3-22.

Hayes, M. 0., and Kana, T. W., 1983, Terrigenous clastic depositional environments some modern examples: A field course sponsored by the American Association of Petroleum Geologists Lecture Notes, pt. 1, p. 55-74.

Howard, J. D., 1971, Comparison of the beach-to-offshore sequence in modern and ancient sediments, in Howard, J. D., Valentine, J. w., and Warme, J. E., Recent advances in paleoecology and ichnology: American Geological Institute Short Course Lecture Notes, p. 148-183. 69

Howard, J. D., Frey, R. w., and Reineck, H. E., 1972, Holocene sediments of the Georgia coastal area, in Frey, R. w., ed., The Neogene of the Georgia coast: University of Georgia, Department of Geology, Guidebook, 8th Annual Georgia Geological Society F'ield Trip, p. 1-58. Howard, J. D., and Reineck, H. E., 1972, Georgia coastal region, Sapelo Island, U.S.A.: sedimentology and biology. IV. Physical and biogenic sedimentary structures of the nearshore shelf: Senckenbergiana Maritima, v. 4, p. 81- 123.

Howell, D. G., and Link, M. H., 1979, Eocene conglomerate sedimentology and basin analysis, San Diego and southern California borderland: Journal of Sedimentary Petrology, v. 49, p. 517-540.

Johnson, K. G., and Friedman, G. M., 1969, The Tully clastic correlatives (Upper Devonian) of New York State: A model for recognition of alluvial, dune(?), tidal, nearshore (bar and lagoon), and offshore sedimentary environments in a tectonic delta complex: Journal of Sedmentary Petrology, v. 39, p. 451-485.

Kanes, W., 1969, Tidal inlets, tidal deltas, and barrier islands versus alluvial deposits:· a discussion of sedimentary criteria, in Donaldson, A. c., ed., Some Appalachian coals and carbonates: modelsof ancient shallow-water deposition: W. Virginia Geologic and Economic Survey, Preconvention GSA Field Trip., Nov. 1969, p. 259-263.

Kappeler, K. A., Squires, R. L., Fritsche, A. E., 1984, Transgressive marginal marine deposits of the Avenal Sandstone, Reef Ridge, central California, in Suchsland, R. J., ed., The Kreyenhagen Formation and related rocks: Society of Economic Paleontologists and Mineralogists, Pacific Section, Symposium, San Diego Convention, April, 1984.

Karp, S. E., Stine meyer, E. H., Church, C. c., Stanton, R. J., and Addicott, W. 0., 1972, Road guides, west side oil fields and outcrop areas of central San Joaquin Valley, in Rennie, E. W., Jr., ed., Guidebook: geology and oil fields, west side central San Joaquin Valley: American Association of Petroleum Geologists, Society of Exploration Geophysicists, Society of Economic Paleontologists, Pacific Sections, 47th Annual Meeting, p. 18- 40.

Keen, A. M., 1971, Sea shells of tropical west America (marine mollusks from Baja California to Peru) (2d ed.): Stanford, Stanford University Press, 1064 p.

Kumar, N., and Sanders, J. E., 197 4, Characteristics of nearshore storm deposits: examples from modern and ancient sediments: American Association of Petroleum Geologists, Annual ·Meetings, Abstracts, San Antonio, Texas, v. 1, 55 p.

1976, Characteristics of shoreface storm deposits: Modern and ancient examples: Journal of Sedimentary Petrology, v. 46, no. 1, p. 145- 162. 70

Laiming, B., 1940a, Some foraminiferal correlations in the Eocene of San Joaquin Valley, California: Sixth Pacific Science Congress Proceedings, v. 2, p. 535-568. ---- 1940b, Foraminiferal correlations in Eocene of San Joaquin Valley, California: American Association of Petroleum Geologists Bulletin, v. 24, p. 1923-1939.

1943, Eocene foraminiferal correlations in California, in Geologic formations and economic development of the oil and gas-fields of California: California Division of Mines Bulletin 118, pt. 2, chap. 6, p. 193-198.

Linder, G., 1978, Seashells of the world: New York, Van Norstrand Reinhold Company, 271 p.

MacKenzie, D. B., 1975, Tidal sand flat deposits in Lower Cretaceous Dakota Group near Denver, Colorado, in Ginsburg, R. N., ed., Tidal Deposits: Berlin, Springer-Verlag, p. 117-125.

Mallory, V. S., 1959, Lower Tertiary biostratigraphy of the California Coast Ranges: American Association of Petroleum Geologists, 416 p.

Mansfield, C. F., 1972, Petrofacies units and sedimentary facies of the Late Mesozoic strata west of Coalinga, California, in Cretaceous of the Coalinga area: Society of Economic Paleontologists and Mineralogists, Pacific Section, Fall Field Trip Guidebook, p. 19-26.

Marsh, 0. T., 1960, Geology of the Orchard Peak area, California: California Division of Mines Special Report 62, p. 3-41.

Martini, E., 1971, Standard Tertiary and Quaternary calcareous nannoplankton zonation, in Farinacci, ed., Proceedings of the Second International Conferenceon planktonic microfossils, Rome 1970, v. 2, p. 739-786.

McCants, C.Y., 1982, Evolution and stratigraphy of a sandy tidal flat complex within a mesotidal estuary (M. S. thesis): University of South Carolina, 108 p.

McCubbin, D. G., 1982, Barrier-island and strand-plain facies, in Scholle, P. A., and Spearing, D., eds., Sandstone depositional environments: American Association of Petroleum Geologists Memoir 31, p. 247-279.

McKee, E. D., 1966, Significance of climbing-ripple structure: U. S. Geological Survey Professional Paper 550-D, p. 94-103. Merriam, c. W., 1941, Fossil turritellas from the Pacific Coast region of North America: University of California Publications in Geological Sciences, v. 26, no. 1, p. 1-214.

Miall, A. D., 1978, Lithofacies types and vertical profile models in braided river deposits, in Miall, A. D., ed., Fluvial sedimentology: Canadian Society of Petroleum-Geologists Memoir 5, p. 543-576. 71

Moreland, Edward, in preparation, Facies interpretation and paleocurrent analysis of Avenal Sandstone Reef Ridge, California (M. S. thesis): Los Angeles, University of California. Morris, P., 1966, A field guide to shells of the Pacific coast and Hawaii (2d ed.): Peterson Field Guide Studies, Boston, Houghton Mifflin Co., 297 p.

Moslow, T. F., 1980, Stratigraphy of mesotidal barrier islands (unpublished Ph.D.): University of South Carolina, 187 p.

Nilsen, T. H., and Clarke, S. H., Jr., 1975, Sedimentation and tectonics in the early Tertiary continental borderland of central California: U. S. Geological Survey Professional Paper 925, 64 p.

Okada, H., and Bukry, D., 1980, Supplementary modification and introduction of code numbers to the low-latitude coccolith biostratigraphic zonation (Bukry 1973-1975): Marine Micropaleontology, v. 5, p. 321-325.

Poore, R. S., 1980, Age and correlation of California Paleogene benthic foraminiferal stages: U. S. Geological Survey Professional Paper 1162-C, 8 p. Powers, M. c., 1953, A new roundness scale for sedimentary particles: Journal of Sedimentary Petrology, v. 23, p. 117-119. Reading, H. G., 1978, Sedimentary environments and facies: New York, Blackwell Scientific Publications, 557 p.

Reading, H. G., 1978, Sedimentary environments and facies: New York, Blackwell Scientific Publications, 557 p.

Reed, R. D., 1924, Role of heavy minerals in the Coalinga Tertiary formations: Economic Geology, v. 19, no. 8, p. 730-749.

Reineck, H. E., and Singh, I. B., 1980, Depositional sedimentary environments: New York, Springer-Verlag, 549 p.

Reinson, G. E., 1979, Barrier island systems, in Walker, R. G., ed., Facies models: Geological Association of Canada, p:-57-74.

Saul, L. R., 1983a, Notes on Paleogene turritellas, venericardias, and molluscan stages of the Simi Valley area, California, in Squires, R. L., and Filewicz, M. V., eds., Cenozoic geology of the-Simi Valley area, southern California: Society of Economic Paleontologists and Mineralogists, Pacific Section, Volume and Guidebook, p. 71-80.

1983b, Turritella zonation across the Cretaceous-Tertiary boundary, California: University of California Publications in Geological Sciences, v. 125, p. 1-165.

Siegfus, S. S., 1939, Stratigraphic features of Reef Ridge Shale in southern California (San Joaquin Valley): American Association of Petroleum Geologists Bulletin, v. 2, no. 1, p. 32-36. 72

Smith, J. P., 1919, Climatic relations of the Tertiary and Quaternary faunas of the California region: California Academy of Sciences Proceedings, 4th series, v. 9, no. 4, p. 123-173. Squires, R. L., 1977, Middle Eocene molluscan assemblage and strati.r;raphy,_ lower Piru Creek, Transverse Ranges, California: California Division oi Mines and Geology Special Report, v. 129, p. 81-86.

--- 1981, A transitional alluvial to marine sequence: the Eocene Llajas Formation, southern California: Journal of Sedimentary Petrology, v. 51, p. 923-938.

---- 1983, Eocene Llajas Formation, Simi Valley, southern California, in Squires, R. L., and Filewicz, M. V., eds., Cenozoic geology of the Simi Valley area, southern California: Society of Economic Paleontologists and Mineralogists, Pacific Section, Volume and Guidebook, p. 81-95.

(in press) Megapaleontology of the Eocene Llajas Formation, Simi Valley, California: Natural History Museum of Los Angeles County, Contributions in Science.

Steinmeyer, E. H., 1972, Pacific Gas and Electric Company pipeline trench section, Kings County, California, in Rennie, E. W., Jr., ed., Guidebook: geology and oil fields, west side central San Joaquin Valley: American Association of Petroleum Geologists, Society of Exploration Geophysicists, Society of Economic Paleontologists and Mineralogists, Pacific Sections, 47th Annual Meeting, p. 70-71.

Stewart, R. B., 1946, Geology of Reef Ridge, Coalinga district (Fresno County), California: u. S. Geological Survey Professional Paper 205-C, p. 81-115. Swift, D. J. P., 1968, Coastal erosion and transgressive stratigraphy: Journal of Geology, v. 76, p. 444-456.

1975, Barrier-island genesis: evidence from the central Atlantic shelf, eastern U.S.A.: Sedimentary Geology, v. 14, p. 1-43. 1976, Coastal sedimentation, in Stanley, D. J., and Swift, D. J. P., eds., Marine sediment transport and environmental management: John Wiley and Sons, New York, p. 225-310.

Vaughan, T. W., 1945, American Paleocene and Eocene larger Foraminifera: Geological Society of America, Memoir 9, pt. 1, 175 p.

Vokes, H. E., 1939, Molluscan faunas of the Domengine and Arroyo Hondo Formations (Fresno County) of the California Eocene: New York Academy of Science Annuls, v. 38, 246 p.

------1940, Paleoecology of the fauna of the Domengine Formation, middle Eocene, California: Sixth Pacific Science Congress, p. 597-605. 73

Von Fstroff, F. E., 1930, Kreyenhagen shale at type locality, Fresno County, California: American Association of Petroleum Geologists, Bulletin, v. 14, no. 10, p. 1321-1336. Weaver, c. E., and others, 1944, Correlation of the marine Cenozoic formations of western North America: Geological Society of America Bulletin, v. 55, p. 569-598.

Weimer, R. J., Howard, J. D., and Lindsay, D. R., 1982, Tidal flats and associated tidal channels, in Scholle, P. A., and Spearing, D., eds., 1982, Sandstone depositional environments: American Association of Petroleum Geologists, Memoir 31, p. 179-280. Wells, J. w., 1940, Two new corals from the Avenal formation (Eocene) of California: Journal of the Washington Academy of Sciences, v. 30, no. 9, p. 374-376.

Wentworth, C. K., 1922, The shapes of beach pebbles: U. S. Geological Survey Professional Paper 131-C, p. 75-83.

Woodring, W. P., Stewart, R. B., and Richards, R. W., 1940, Geology of Kettleman Hills oil field, California: U. S. Geological Survey Professional Paper 195, 170 p.

Zingg, Th., 1935, Beitrage zur Schotteranalyse: Min. Petrog. Mitt Schweiz., v. 15, p. 39-140. APPENDIX 1 RESULTS OF ROCII:-EVAL PYROLYSIS Depth Intend Tux 51 52 53 T .o.c. Hydroaen Cbyaea Sa•ple No. (Ft.) (c) (•s/s) (•a/s) (ms/s) PI PC* (vt.%) Index Indu

2712-001 Arroyo Pinos 439 0.07 0.02 0. 72 0.87 0.00 0.34, s 211

53 • C02 produced fro• karoaen pyrolyda (ms C02/a of rock) r.o.c. • Total oraantc carbon, vt.:a: 51 PC* • 0,083 (51 + 51.) • Pre• hydrocarbone, •a HC/a of roc:l: Hydrogen Index • •f C02/1 or1anlc carbon 52 • ~aldual hydrocarbon potential Index • 111 UC/a oraanfc carbon PI • S /51 + 52 <•a HC/a of rock) Oxysen ,..... • Temperatura Index, deareea C,

VITRINITE REFLECTANCE SUMMARY

fYPE NUMBER MINIMUM MAXIMUM MEAN DEPTH OF POPULATION OF REFLECTANCE REFLECTANCE REFLECTANCE STD. DEY. SAMPLE (lui) NUMBER SAMPLE READINGS ( %Ro) !%Ro) I% Ro) (% Ra) REMARKS

2712-001 26-225-lSE CUl'CROP Ill 36 0.40 0.61 0.49 0.066 INDIGENOUS (Arroyo (2) 23 0.72 1.20 0.97 0.153 REWORKED Pino~) (3) 1 1.34 1.34 1.34 - REWORKED

-..J .p- VISUAL KEROGEN ASSESSMENT WORKSHEET GENERAL CAVED AND/OR ~ARV INDIGENOUS POPULATION (INTERPRETED) CHARACTERISTICS REWORKED POPULATION($) ORGANIC MATTER COLOR OF STAT[ OF' TYPE C1F IORGAHIC MATTER IORGANtC MmTER I '% IORGAN_I_~ -~"~!-~--~ I IIIATURATION INDEX TVPE

lmz-ool I Auon.._ \I;Am(Al)-11:! Pinos - ..

·I 1-l-l-··-·--·-·-··

...... V1 76 " '

CRUDE OIL ANALYSIS RESULTS

Sample No.: 2712-002 Identification No.: Avenal Sand

GROSS COMPOSITION

Less than cl5+ •••••••••••••••••••• 10.2% ciS+ •••••••••••••••••••••••••••••• 89.8%

ClS+ COMPOSITION

Asphaltene (ASPH) ••••••••••••••••• 12.9% Saturate Hydrocarbons (SAT) ••••••• 23.1% Aromatic Hydrocarbons (AROM) •••••• 37.n.: Eluted NSO Compounds (NSO) ••••••• 16.5% Noneluted NSO Compounds (NSO) ••••• 9.8%

RATIOS

PN AROM 0.61%

ASPH NSO 0.49%

Summary of C15+ Soxhlet Extraction; Deasphaltening and Liquid ChromatographY

A. Weights of Extract3 and Chromatographic Fractions

Weight of Total Precipitated N-C5 Parafrin3- Eluted None luted Sample Rock Extd. Extract Asphaltenes Soluble Sulfur Naphthene3 Aromat1c3 !ISO'S !ISO'S Number (gra""') (gra..,.) (grams) (gra""') (grams) (grams) (grams) (grams) (grams)

2712-001 Arroyo Pinos 100.0 0.0133 0.0099 0.0034 N.D. N.D. N.D. N.D. N.D.

B. Concentration of Extracted Materials in Rock

------Hydrocarbons------Nonhydrocarbons------Total Paraffin- Preolptd. Eluted Noneluted Sample Extract Naphthene Aromatic Total Sulfur Asphaltene NSO'S NSO'S Total Number (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

2712-001 Arroyo Pinos 133 99

C. Composition or Extracts

------Hydrocarbons------Nonhydrocarbona------Paraffin- Eluted Noneluted Prec1p.i.td. Sample Naphthene .Aromatic Sulfur !ISO'S !ISO'S bphaltene HC'S Number S S PN/Arom S S S J .Asph/NSO ~ HC/Non HC

2712-001 Arroyo Pinos 74.4 NO. 2712-001 TYPE OF SAMPLE: a.m::ROP GETI"i OIL m!PANY WELL NAME

(NO. OP READHl;S------= 60) 0.40 0.40 0.41 0.41 0.41 0.42 0.43 0.43 ------0.44 0.44 0.45 0.45 0.45 0.45 0.46 0.46 0.46 0.47 0.47 0.50 0.50 0.50 0.51 0.51 0.53 0.53 0.54 0.56 0.56 0.56 0.58 0.59 0.59 0.60 0.60 0.61 0.72 0.74 0.76 0.79 0.82 0.84 0.87 0.91 0.91 0.94 0.94 0.95 0.95 0.96 1.01 1.07 1.10 1.13 1.14 1.16 1.18 1.19 1.20 1.34 POPULATION NO. OF READINGS MIN. Ro (%) MAX. Ro ( %) MEAN Ro ( %) STD. DEV (%) REMARKS (!) 36 0.40 0.61 0.49 0.066 (2) 23 0.72 1.20 0.97 0.153 ( 3) 1 1.34 1.34 1.34

Zl C - CAVE OONTI\MINATION (/) X - INDIGENOUS POPUI.li.TION (!) z 0- REOCLED - II 0

0 'r I 1 1 I 1 I I I I I I I I I I I I I I -tt..... l .. I -t"J""j'•"tt'r"'t I I I ill I I I I I I ri1 I I If I til j I I jjjl I I I I ti I I I I I I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i i i i i J i I I I I I I J I I I I I I I I I I i t 00 01 02 o.J o 4 o., o.&.. o:r o.e 09 1.0 1.1 12 I.J 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 VITRINITE REFLECTANCE HISTOGRAM

..., C15+ Paraffin-Naphthene

Arroyo Pinoso 24

26 22

21 23 28 29 0

19 31 27 2~ 30

.. 32 n

18 34

I I I I J -

...., 00 79

cOIJ ..cOIJ ~ ..c c. z"' b .... ., .... c ..."' Cl.l"' p.,"' .... j:, -c"' .... OIJ u ~

. ------=--=-~· -=---==------APPENDIX 2

MEGAFOSSIL LOCALITIES

All are California State University, Northridge (CSUN) localities.

760. At elevation of 985 ft along east bank of Sulphur Spring Canyon just south of a swampy area, 1500 ft (457 m) south and 1500 ft (457 m) west of NE corner of section 35, T23S, R17E, Kettleman Plain, California, 7.5-minute quadrangle,

1953.

761. At elevation of 1150 ft along west side of Little Tar Canyon near its mouth, 1000 ft (305m) north and 2450 ft (747 m) west of SE corner of section 27,

T23S, R17E, Kettleman Plain, California, 7.5-minute quadrangle, 1953.

762. At elevation of 1500 ft on south side of hill, 1850 ft (564 m) north and 1150 ft (350 m) east of SW corner of section 21, T23S, R17E, Garza Peak, California,

7.5-minute quadrangle, 1953.

763. At elevation of 1400 ft at Roof Spring, 2300 ft (701 m) north and 625 ft

(191 m) east of SW corner of section 21, T23S, R17E, Garza Peak, California,

7.5-minute quadrangle, 1953.

764. At elevation of 1525 ft on west side of canyon, 550 ft (168 m) south and

1550 ft (472 m) west of NE corner of section 20, T23S, R17E, Garza Peak,

California, 7.5-minute quadrangle, 1953.

80 81

765. At elevation of 1650 ft on west side of a small canyon, 300 ft (91 m) north and 2550 ft (686 m) west of SE corner of section 17, T23S, R17E, Garza Peak, California, 7.5-minute quadrangle, 1953.

766. At elevation of 1725 ft on south side of hill, 350 ft (107 m) north and 2850 ft (869 m) west of SE corner of section 17, T23S, R17E, Garza Peak, California,

7.5-minute quadrangle, 1953.

767. At elevation of 1725 ft on south side of hill, 1400 ft (427 m) north and 600 ft (183 m) east of SW corner of section 17, T23S, R17E, Garza Peak, California,

7.5-minute quadrangle, 1953.

768. At elevation of 2050 ft on east side of south fork of Garza Creek, 1150 ft

(351 m) south and 2350 ft (716 m) west of NE corner of section 10, T23S, R 16E,

Garza Peak, California, 7.5-minute quadrangle, 1953.

769. At elevation of 1815 ft on west side of Zapato Canyon, 900 ft (274 m) south and 2000 ft (610 m) west of NE corner of section 21, T22S, R15E, Kreyenhagen

Hills, California, 7.5-minute quadrangle, 1956, photo revised 1971. APPENDIX 3

MICROFOSSIL LOCALITIES

All are California State University, Northridge (CSUN) localities.

KK-1. At elevation of 1300 ft along west bank of Little Tar Canyon on top of a

knoll, 1400 ft (427 m) south and 2450 ft (747 m) west of SE corner of section 27,

T23S, R17E, Kettleman Plain, California, 7.5-minute quadrangle, 1953.

KK-2. At elevation of 2210 ft on the east side above Garza Canyon along the

upper fire road, 1250 ft (381 m) south and 1900 ft (580 m) west of NE corner of

section 10, T23S, R16E, Garza Peak, California, 7.5-minute quadrangle, 1953.

KK-3. At elevation of 2210 ft on the east side above Garza Canyon along the upper fire road, 1250 ft (381 m) south and 1850 ft (564 m) west of NE corner of section 10, T23S, R16E, Garza Peak, California, 7.5-minute quadrangle, 1953.

KK-4. At elevation of 1800 ft along the west side of Garza Canyon, 1100 ft (336

m) south and 2250 ft (686 m) east of NW corner of section 10, T23S, R16E, Garza

Peak, California, 7.5-minute quadrangle, 1953.

KK-5. At elevation of 1800 ft along the east side of Garza Canyon, 1100 ft (336 m) south and 2500 ft (763 m) east of NW corner of section 10, T23S, R16E, Garza

Peak, California, 7.5-minute quadrangle, 1953.

82 83

KK-6. At elevation 1700 ft along the east side of Garza Canyon, 350 ft (107 rn) south and 2600 ft (793 rn) west NE corner of section 10, T23S, R16E, Garza Peak,

California, 7.5-minute quadrangle, 1953.

KK-7. At.elevation 1660 ft along the east side of Garza Canyon, 950ft (290m) south and 210ft (641 m) west NE corner of section 26, T22S, R15E, Garza Peak,

California, 7.5-minute quadrangle, 1953.

KK-8. At elevation 1640 ft along the west side of Garza Canyon, 500ft (153 rn) south and 1900 ft (580 rn) west NE corner of section 26, T22S, R15E, Garza Peak,

California, 7.5-minute quadrangle, 1953.

KK-9. At elevation 1640 ft along the west side of Garza Canyon, 350ft (107 rn) south and 1750 ft (534 m) west NE corner of section 26, T22S, R15E, Garza Peak,

California, 7.5-minute quadrangle, 1953.

KK-10. At elevation 1765 ft along the west side of Zapato Canyon, 1100 ft (336 m) south and 1900 ft (580 rn) west NE corner of section 21, T22S, R15E,

Kreyenhagen Hills, California, 7.5-minute quadrangle, 1956, photo revised 1971. 84

GREEN AND ASSOCIATES PALEONTOLOGICAL SERVICES 7026 Comstock Avenue Whittier, California 90602 (213) 698-5338

January 9, 1984

TO: Mr. S.A. Reid Getty Oil Compa~y 1601 New Stine Road Bakersfield, California 93389

RE: Outcrop Samples fro~ the Coalinga Area

FORMUNIFERAL REPORT

This report is based on the analysis of ten outcrop samples from the Coalinga area. Standard techniques were applied in processing the samples; the foraminifera were picked and identified to determine the ages.and depositional environments. The following is a summary of our results: · KK-10

This sample c~ntains frequent highly developed arenaceous foraminifera, which are considered to be of Late Cretaceous age. Their occurrence - together with ~9nides bandyi and Pleuro~tomella subnodosa - points to a middle neritic to upper bathyal depositional environment probably under slight hyposaline r.0ndition.

Age: Late Cretaceous (uncifferentiatec) Foraminifera: Ammodiscus glabratus, Haplaphragmoides excavata, Haploohraomoides kirki, Gaudrvina sp., Marsonella oxvcona. Tritaxia sp., Pleurostomella suhnodosa, EoQtlides bandvi KK-4 Age: Non-diagnostic

Depositio~al environment: Non-diagnostic Foraminifera: No foraminifera. Two megaspores occurred in this sample. 85

KK-1

The abundant planktonic foraminiferal association in this sample is referred to the Globorotalia ~Q~~ Zone (P.S of the planktonic foraminiferal zonation of Blow, 1969, Late middle Eocene to Recent planktonic foraminiferal biostratigraphy: Internatl. Conf. Plankto. Microfoss., lst., Geneva, 1967, Proc., Vol.l, _p. 199-422), which is of Middle Eocene (Ulatisian) age. A bathyal depositional environment under open marine condition can be postulated with certainty.

Age: P.S/Middle Eocene (Ulatisian) Foraminifera: Globorotalia"aragonensis; Globorotalia caucas1ca, globorotalia quetra, Gl~borotalia boolbrooki, Globorotalia broedermanni, Globorotalia pseudotooilensis. Glob~otalia formosa gracilis, Globigerina soldadoens1s, Globigerina linaoerta, Globigerina nitida, Gyroidina orbicularis var. planata, Oridorsalis umbonatus KK-2

The foraminifera from this sample range in age from Ulatisian to Narizian foraminifera.

Foraminifera: Asterigerina crassaformis, Bulimina corrugata, Glolocassidulina globosa, Cibicidoides venezuelanus, Globiaerina linaperta

Age: Ulatisian-Narizian KK-3 This sample is considered to be the same age as the sample GP-9 based on similar foraminiferal associations. However, due to the higher content of planktonic foraminifera here, a slightly deeper position and/or stronger open marine influence and/or the surface waters may have become more saline.

Age: Ulatisian-Narizian

Foraminifera: Globorotal~ nentacamerata, Globiaerina frontosa, Globiacrlna eocaena, Globiaerina corpulenta, Globiaerina inaeguispir~. Globiaerina linaperta, Oridossalis umbonatus, Asteriaerina crassaformis, Bulimina corruoata, Stilostomella spinea, Gyroidina orbtcularis var. planata 86

KK-7

Age: Non-diagnostic

Depositional environment: Non-diagnostic

Foraminifera: Barren KK-5

This sample is characterized by the presence of pyritized organic remains (foraMinifera. diatoms. internal casts of gastropoda). Due to the poor preservation of the organic remains and the long geologic range of the identified genera they are not suitable for age determination. However. they are indicative·for relatively shallow water facies (i~r to middle neritic) of probably low oxygen content during deposition. ·

Foraminifera: Elphidium spp. and Quinguelo.culina sp.

Age: Non-diagnostic

Depositional env~ronment: Non-diagnostic Foraminifera: BaTren KK-6 Age: Non-diagnostic

Depositional environment: Non-diagnostic Foraminifera: Barren KK-9 The foraminifera in this sample do not enable an exact age determination. The species listed below are regarded to have their characteristic/typical occurrence in Ulatisian. although they are not restricted to that stage. A middle to outer neritic environ ment during deposition may be concluded.

Age: Probably Ulatisian Foraminifera: Cibicidoides venezuelanus. Vaginulinopsis asoeruliformis. Globocassidulina globosa. Lenticulina alato-limbata