Stratigraphy of the Southern Coast Ranges near the San Andreas Fault from Cholame to Maricopa, California
GEOLOGICAL SURVEY PROFESSIONAL PAPER 764 Stratigraphy of the Southern Coast Ranges near the San Andreas Fault from Gholame to Maricopa, California
By T. W. DIBBLEE, JR.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 764
A discussion of the regional stratigraphy of the McLure Valley area, Temblor Range, Carrizo Plain, Cuyama Valley, Caliente Range, La Panza Range, and Sierra Madre Mountains
UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1973 UNITED STATES DEPARTMENT OF THE INTERIOR
ROGERS C. B. MORTON, Secretary
GEOLOGICAL SURVEY
V. E. McKelvey, Director
Library of Congress catalog-card No. 72-600327
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 Price: Paper cover-80 cents, domestic postpaid; 55 cents, GPO Bookstore. Stock No. 2401-00300 CONTENTS
Page Page Abstract ______1 Middle Tertiary sedimentary sequence Continued Introduction ______1 Vaqueros and Temblor Formations Continued Scope and purpose ______1 Temblor Formation Continued Problems of stratigraphic terminology ______3 Buttonbed Sandstone Member ______23 Chronology used ______3 Monterey Shale ______24 Tectonic areas ______5 Review of nomenclature ______24 Crystalline plutonic and metamorphic rocks ______5 Stratigraphic units southwest of the San Eugeosynclinal sedimentary and igneous rocks _____ 6 Andreas fault 24 Definition ______6 Saltos Shale Member ______25 Franciscan rocks ______6 Whiterock Bluff Shale Member ____ 26 Ultramafic rocks ______6 Stratigraphic units northeast of the San Jurassic (?) and Cretaceous marine sedimentary se Andreas fault. 27 quence ______6 Gould Shale Member __ 28 Definition ______6 Devilwater Shale Member 29 Gravelly Flat Formation ______7 Interbedded shale and sandstone mem Hex Claystone ______8 ber ______29 Panoche Formation ______8 McLure Shale Member __ 29 Upper Cretaceous and lower Tertiary marine sedi Belridge Diatomite Member 30 mentary sequence ______9 Branch Canyon Sandstone ___ 30 Definition ___i______9 Santa Margarita Formation ___ 31 Marine clastic sedimentary rocks ______9 Caliente Formation 31 Lower Tertiary marine sedimentary sequence ______10 Basalt ______-___ 32 Definition ______10 Bitterwater Creek Shale _____ 33 Lodo(?) Formation ______10 Reef Ridge Shale ______33 Avenal Sandstone ______10 Kreyenhagen Shale ______12 Upper Tertiary sedimentary sequence 33 Point of Rocks Sandstone ______13 Definition _____ 33 Wagonwheel Formation ______13 Deposits in the San Joaquin Valley area 34 Middle Tertiary sedimentary sequence ______13 Terminology __ 34 Definition ______13 Etchegoin Formation 36 Simmler Formation ______14 San Joaquin Formation 37 Vaqueros and Temblor Formations ______15 Deposits in the Salinas Valley-Cuyama Valley Review of nomenclature ______15 area _____ 37 Vaqueros Formation ______17 Unnamed marine sediments _ 37 Quail Canyon Sandstone Member __ 17 Quatal Formation 38 Soda Lake Shale Member ______17 Morales Formation 38 Painted Rock Sandstone Member 18 Valley deposits 39 Temblor Formation ______18 Definition ______39 Cymric Shale Member ______20 Paso Robles Formation 39 Wygal Sandstone Member ______20 Tulare Formation _ 40 Santos Shale and Agua Sandstone Mem Surficial deposits 41 bers ______22 Relationship of sedimentary sequences to the San Carneros Sandstone Member ______23 Andreas fault _ _ 41 Media Shale Member ______23 References cited _ '- 42
ILLUSTRATIONS
Page FIGURE 1. Index map of part of central California showing area studied ______1 2. Generalized geologic map showing distribution of major stratigraphic sequences in the southern Coast Ranges near the San Andreas fault from Cholame and Avenal to Cuyama and Maricopa III IV CONTENTS Page FIGURES 3-8. Stratigraphic diagrams showing: 3. Major Mesozoic and Cenozoic sedimentary sequences of the southern Coast Ranges near the San Andreas fault from Cholame and Avenal to Cuyama and Maricopa 3 4. Cretaceous and Cenozoic chronology of the southern Coast Ranges 4 5. Jurassic (?) and Cretaceous marine sedimentary sequence in the southeastern part of the Diablo Range and in the Temblor Range 7 6. Lower Tertiary marine sedimentary sequence in part of the Diablo Range between McLure and Cholame Valleys and in the Temblor Range 11 7. Lithologic units of the middle Tertiary sedimentary sequence southwest of the San Andreas fault from Cholame to Cuyama _ _ 14 8. Lithologic units of the middle Tertiary sedimentary sequence northeast of the San Andreas fault from Avenal to Maricopa 15 9. Map of the Temblor Range showing geographic localities mentioned and areal extent of the Tertiary formations ______19 10. Geologic map of the Chico Martinez Creek area, Temblor Range, showing members of the Temblor Formation and Monterey Shale ______21 11. Stratigraphic diagram showing sections of the Temblor Formation from Cedar Creek to Zemorra Creek in the Temblor Range ______-_ _ - 22 12. Map showing probable original and present areal extent of contemporaneous formations or facies of mainly middle and late Miocene age in southern Coast Ranges ___ _ _ 25 13. Diagram showing classification and names applied to the upper Tertiary (Pliocene) sedimentary se quence in southeastern part of the Diablo Range and Kettleman Hills 35 14. Stratigraphic diagram showing valley deposits and upper Tertiary sedimentary sequence of the San Joaquin Valley area along east side of the southeastern part of the Diablo Range, Kettleman Hills, and the Temblor Range ______-_ 36
TABLES
Page TABLE 1. Names applied by other investigators to strata herein assigned to the Vaqueros and Temblor Forma tions of map region of figure 2 ______16 2. Local Stratigraphic units of the Temblor Formation in the Temblor Range between Chico Martinez Creek and Bitterwater Creek ______20 3. Members of the Temblor Formation exposed at Devils Den ______24 STRATIGRAPHY OF THE SOUTHERN COAST RANGES NEAR THE SAN ANDREAS FAULT FROM CHOLAME TO MARICOPA, CALIFORNIA
By T. W. DIBBLEE, JR.
ABSTRACT 122 120° The upper Mesozoic and Cenozoic sedimentary series within about 20 miles on either side of the San Andreas fault has been mapped and systematically classified. South west of the fault, the sedimentary series overlies a Mesozoic crystalline basement of plutonic and metamorphic rocks, is from 5,000 to 40,000 feet thick, and is divided into four lithologic sequences. Northeast of the fault, the sedimentary series overlies a Mesozoic basement of eugeosynclinal rocks (Franciscan rocks and serpentine), is from 25,000 to 40,000 feet thick, and is divided into five lithologic sequences. These sequences are in large part separated by regional uncon formities. The Cretaceous and Tertiary sequences are marine and terrestrial southwest of the fault, marine northeast of it. The youngest sequence, mainly of Quaternary age, is composed of lithologically similar valley sediments on each side of the fault. Most of the sedimentary sequences are divided into litho logically distinct formations of large areal extent, some of which in turn are divided into local members. A standardized set of names has been designated for the formations and members for this region, using the existing names that are applicable. On opposite sides of the San Andreas fault, not only are the basement rocks contrasting, but the oldest correspond ing sedimentary sequences are dissimilar; the successively younger sequences are progressively less different. This con dition appears to be the result of persistent right-lateral movement on the fault since Cretaceous time. INTRODUCTION SCOPE AND PURPOSE The areal geology of about 20 miles on either side of an 80-mile segment of the San Andreas fault from Cholame and Avenal to Cuyama and Mari- FIGURE 1. Index map of part of central California. Area copa (fig. 1) has been mapped and compiled at a studied, indicated by dashed outline, is shown in figure 2. scale of 1:125,000, or 2 miles to 1 inch (Dibblee, 1973b). The region mapped is in the southern drilled for oil or gas is shown in five cross sections Coast Ranges and includes the extreme southeastern (Wagner and others, 1973). The purpose of the part of the Diablo Range, all the Temblor Range, geologic map (Dibblee, 1973b) and cross sections Carrizo Plain, Caliente and La Panza Ranges, (Wagner and others, 1973) is to portray the re Sierra Madre Mountains, and much of Cuyama gional geology and to provide a geologic background Valley (fig. 2). for earthquake investigations and geophysical The subsurface geology of this area based on the studies in progress or contemplated along this great areal geology mapped and on logs of test holes active fault. STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA
EXPLANATION
Contact
Middle Tertiary sedi Upper Jurassic (?) and Fault mentary sequence Cretaceous marine Dotted where concealed sedimentary sequence or inferred
Lower Tertiary marine sedimentary sequence Eugeosynclinal sedimen tary and igneous rocks Upper Tertiary sedi mentary sequence Upper Cretaceous and lower Tertiary marine Crystalline plutonic and sedimentary sequence metamorphic rocks
FIGURE 2. Distribution of major sequence in the Southern Coast Ranges near the San Andreas fault from Cholame and Avenal to Cuyama and Maricopa.
The .purpose of this report is to supplement the terminology, it was necessary to (1) designate the description of the rock units on the geologic map major and minor lithostratigraphic units that are (Dibblee, 1973b) with a discussion of their strati physically recognizable and mappable throughout graphy in this region. To resolve the problems in the region, (2) review the stratigraphic name or INTRODUCTION names that have been applied to each unit by pre SOUTHWEST OF SAN NORTHEAST OF SAN vious investigators, and (3) suggest the best desig AGE ANDREAS FAULT TO ANDREAS FAULT TO nation for each unit. RINCONADA FAULT SAN JOAQUIN VALLEY 1 X Surficial deposits PROBLEMS OF STRATIGRAPHIC TERMINOLOGY -v_x-\/-^_/ v_^\^-^x~v_/-S_x--v_x £K Pleisto The map area (fig. 2) is one in which the Meso- << Valley deposits zoic and Cenozoic stratigraphy is exceedingly com cene ? ?? plex because of many unconformities and lateral 0 Upper Tertiary Upper Tertiary O sedimentary sedimentary variations in lithology and thickness resulting from M Plio O sequence sequence deposition concurrent with tectonic movement. Dur z cene (terrestrial and (marine) LJ ing pioneer geologic investigations of the oil and marine) O v^x-v^-~V^ V_/~v^ gas districts of this region in the early twentieth ?? century, attempts were made to delineate major Middle Tertiary Middle Tertiary stratigraphic units on the basis of reconnaissance Mio sedimentary sedimentary sequence sequence cene mapping. Later, more detailed investigations re o: (marine terrestrial (marine) vealed stratigraphic complexities not recognized in H and volcanic) the earlier investigations. Correlation problems be cr Oligo- 1-LU cene came evident and led to the naming of numerous (Absent) local stratigraphic units. As a result, each district ?? Lower Tertiary marine has its own set of locally recognized stratigraphic Eocene sedimentary units, and no major regional stratigraphic units of Upper Cretaceous sequence ?? and lower Tertiary the California Coast Ranges have been established. marine ^^^v^^^-^^^^V-x^s. Thus, the stratigraphic terminology is somewhat Paleo- sedimentary (Absent) \ chaotic. cene sequence The most practical approach to regional mapping was to recognize and map the major stratigraphic -^ Upper Jurassic(?) O CRETA- and Cretaceous divisions with a characteristic lithology of regional O CEOUS marine (Absent) extent. These are informally designated herein as s sedimentary CO sedimentary "sequences" and shown in figure 3. UJ sequence s Their areal extent is shown in figure 2. All are in CRETA Crystalline Eugeosynclinal large part separated by unconformities. The upper CEOUS Plutonic and sedimentary most sequence is terrestrial; the other sequences AND metamorphic and igneous are all or largely marine. Each marine sequence OLDER rocks rocks represents a complete or nearly complete sedimen FIGURE 3. Major Mesozoic and Cenozoic sedimentary se tary cycle of marine transgression, inundation, and quences of the southern Coast Ranges near the San Andreas regression. These sequences are divided into map- fault from Cholame and Avenal to Cuyama and Maricopa. pable units designated as lithologically distinct Regional unconformities indicated by wavy lines. formations. Where convenient, these in turn are divided into local units, such as members or fades. CHRONOLOGY USED This report discusses the pertinent terminology and Each stratigraphic unit is assigned to the "ages" evidence for the age of each stratigraphic unit, as and (or) stages currently recognizable in California well as discrepancies and problems involved. on the basis of stratigraphic and paleontologic evi In figure 3 and in those figures that follow, time dence. Tentative correlations from one chronology boundaries of the standard European systems and to another are indicated in figure 4 by horizontal series are suggested only by queries. Definite bound dotted lines. Assignment of the units to the stand aries are not shown because of (1) uncertainties in ard European series is controversial and not yet the definitions of the European series or epochs, definitely resolved. (2) uncertainties involved in the assignment of the The terrestrial mammalian "ages" in figure 4 are faunal stages and "ages" to those epochs, and (3) those proposed by Wood and others (1941) and by uncertainties of correlation of the terrestrial ver Savage, Downs, and Poe (1954), with modifications tebrate "ages" with the marine molluscan "ages" by Evernden, Savage, Curtis, and James (1964). and microfaunal stages of the Pacific Coast region. None were defined with reference to type sections. The resolution of these controversial correlation Volcanic samples from rock units within each "age" problems is beyond the scope of this report; hence have been radiometrically dated by Evernden, Sav the queries. age, Curtis, and James (1964) and Turner (1970), STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA
MAMMA RADIO- FORAMIN- < SYS MOLLUSCAN sr SERIES LIAN METRIC IFERAL u TEM "AGES" "AGES" AGES 1 STAGES
Holocene *£ r- £ Rancho- "Upper labrean Pleistocene" zz Pleistocene Irving- "Lower CX Pleistocene" tonian I 5 ...... "San Joaquin" Blancan Upper and "Etchegoin" CL Pliocene 4 Q. Hemp- ID Lower "Jacalitos" hillian 10 ...... ?
Claren- "Delmontian" 2 "Santa Upper donian Mohnian Margarita" 12?---? CENOZOIC 13? Luisian
Upper Narizian "Tejon"
Eocene Middle Ulatisian "Domengine" <5 o Lower Penutian "Capay"
Upper Bulitian "Meganos" Paleocene Lower Ynezian "Martinez"
Maestrichtian Campanian w Santonian w Upper Coniacian ^ CRETACEOUS Turonian i- MESOZOIC Cenomanian w Albian Aptian Barremian ^ Lower Hauterivian w Valanginian 0- _ . o Bernasian ^ ;.) *% u ->^ 1 Potassium-argon dates in millions of years (Evernden and others, 1964, and Turner. 1970). 2Now considered part of Mohnian Stage (R. L. Pierce, oral commun., 1970) FIGURE 4. Cretaceous and Cenozoic chronology of the southern Coast Ranges. Diagonal dotted lines indicate correla tions with the standard European series (Durham, 1954, fig. 3; Savage and others, 1954, fig. 10); horizontal dotted lines indicate questionable but tentative correlations. CRYSTALLINE PLUTONIC AND METAMORPHIC ROCKS who determined the approximate age in millions of assumed to be the Nacimiento fault (Vedder and years of the boundaries of those "ages." Correlation Brown, 1968). Recent mapping by the writer, how of the "age" boundaries with the standard Euro ever, reveals that the Rinconada fault as shown in pean series as inferred by Durham (1954, fig. 3) and figure 2 is continuous to the northwest not with the Savage, Downs, and Poe (1954, fig. 10) is indicated Nacimiento fault of Taliaferro (1943) but with the in figure 4. Figure 4 is based on the correlation by Rinconada fault (Jennings, 1958) northwest of Turner (1970, fig. 9) of the mammalian "ages" with Atascadero. Southeastward from Atascadero, how the foraminiferal stages and on the currently ac ever, the Rinconada fault (fig. 2) is largely within cepted assignment of those stages and correlative the Sur-Nacimiento fault zone as defined by Page molluscan ages to the European series. (1970). The marine foraminiferal stages assigned to the It is noteworthy that not only do these two juxta middle Tertiary system were proposed and defined posed tectonic areas have contrasting basement by Kleinpell (1938), and those assigned to the lower rocks, but they also have dissimilar sedimentary Tertiary were proposed and defined by Mallory sequences; the successively younger corresponding (1959). Correlation of the middle Tertiary stages sequences are progressively more similar (fig. 3). with corresponding mammalian "ages" is adopted This dissimilarity is interpreted to be the result of from Turner (1970, fig. 9), who radiometrically recurrent or continuous lateral movements on the dated the approximate boundaries of most of those San Andreas fault during or after deposition of stages as well as those of the mammalian "ages." each sedimentary sequence since Cretaceous time, Assignment of the foraminiferal stages to the Euro as inferred by Hill and Dibblee (1953, p. 445-449) pean series is adopted from Weaver and others and discussed further at the end of this report. (1944, chart 11), with modifications from Bandy and Arnal (1969, p. 786). CRYSTALLINE PLUTONIC AND Marine molluscan "ages" have been proposed or METAMORPHIC ROCKS listed but never adequately defined. Those shown are the ones currently recognized for the southern In the Salinia block of Reed (1933) between the Coast Ranges by W. O. Addicott (oral commun., San Andreas and Rinconada faults, the Cretaceous 1970). Assignment of those ages to the European and Cenozoic sedimentary rocks are underlain by a series is modified after Weaver and others (1944, crystalline basement complex of plutonic and meta- chart 11). Those assigned to the Quaternary and morphic rocks. The basement is exposed extensively upper Tertiary are listed by Durham (1954, ch. 3, in the northern part of the La Panza Range, where p. 25); those to the middle Tertiary were proposed it is composed of massive granitic rocks, mainly by Corey (1954, ,p. 82), and those to the lower Ter granodiorite. These rocks were formerly thought tiary, by Clark and Yokes (1936). to be of Jurassic age or older on the basis of their Fossils have been reported from only very few supposed correlation with granitic rocks of that age places in the Mesozoic rocks; so, only a very general in the Sierra Nevada (Reed, 1933, p. 86). However, assignment of their ages to the European systems the granitic rocks of the La Panza Range are now and stages can be inferred. Lack of microfaunal data considered to be about 80.5 million years old, or from these rocks precludes their assignment to the Late Cretaceous (Turonian Stage), on the basis of foraminiferal stages proposed by Goudkoff (1945) radiometric dating (Curtis and others, 1958; Hay, and recognized by Church (1968). 1963, p. 113), if this is the age of the emplacement of these rocks and not a later event. TECTONIC AREAS The most southeasterly exposure of crystalline The region discussed in this report (fig. 2) is rocks in La Panza Range (10 miles west of Soda divisible by the San Andreas fault or some of its Lake, fig. 2) shows mainly gneissic rocks, including strands into two tectonic areas of dissimilar base quartzite and marble, metamorphosed from pre ment rocks and sedimentary sequences. The area existing rocks of Mesozoic age or older. In the Hed on the northeast, which has a basement of eugeo- Hills, gneissic quartz diorite, probably metamor synclinal sedimentary and igneous rocks, extends phosed from similar preexisting rocks, is exposed. into the San Joaquin Valley. The area to the south Plutonic rock exposed at Gold Hill, about 8 miles west, which is part of the Salinia block of Reed north of Cholame, is an amphibolite composed of (1933, p. 12, fig. 16), has a basement of crystalline hornblende quartz gabbro. It is probably an amphib rocks and extends to the Rinconada fault (fig. 2). olite facies of the plutonic rocks exposed west of Much of the Rinconada fault as shown is commonly the fault, as is suggested by an inclusion of marble. 495-417 O - 73 - 2 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA The gabbro has been radiometrically dated as about 719), yet the lowest units of the superjacent sedi 143 million years old, or Jurassic in age (Hay, 1963, mentary sequence in the Diablo Range contain fos p. 113). sils inferred to indicate Early Cretaceous age. The Franciscan of western California is generally con EUGEOSYNCLINAL SEDIMENTARY AND sidered to range in age from Late Jurassic (Tith- IGNEOUS ROCKS onian) to Late Cretaceous (Turonian) only on the DEFINITION basis of fossils from a few localities (Bailey and Northeast of the San Andreas fault (with the others, 1964, p. 122). The age relationship of the exception of Gold Hill in Cholame Valley), the low Franciscan to the crystalline basement complex est major rock division is a generally unmetamor- across the San Andreas fault is not definitely known. phosed but severely deformed assemblage of eugeo- ULTRAMAFIC ROCKS synclinal sedimentary and mafic igneous rocks. It In the area within figure 2, the uliramafic rocks forms the basement complex upon which the upper are composed mainly of serpentine and partly of Mesozoic and Cenozoic miogeosynclinal sedimentary serpentinized peridotite. They are intricately asso sequences rest. The sedimentary and volcanic rocks ciated with Franciscan rocks in the form of numer that make up most of this assemblage are known ous lenticular sill-like masses, some large, either informally as Franciscan rocks (Bailey and others, intrusive or injected into the Franciscan rocks. 1964). Ultramafic igneous rocks intruding the Many are at or near the top of this assemblage in Franciscan rocks form part of the eugeosynclinal contact with the overlying Jurrassic(?) and Cre complex. taceous marine sedimentary sequence, but none are Exposures of the eugeosynclinal assemblage in found within that sequence. All the serpentinous the Temblor Range are the southeasternmost in the masses are pervasively sheared or shattered, either Coast Ranges northeast of the San Andreas fault. because of expansion that occurred as a result of This assemblage is exposed extensively in the Diablo serpentinization, because of tectonic movements, or Range to the northwest, mostly beyond the map both. These ultramafic rocks are presumably Early area. Cretaceous and (or) possibly Late Jurassic in age. FRANCISCAN ROCKS JURASSIC(?) AND CRETACEOUS MARINE As in other parts of the Coast Ranges province, SEDIMENTARY SEQUENCE the Franciscan rocks, as designated by Bailey, Irwin, and Jones (1964, figs. 1, 2, 3; pi. 1), form an DEFINITION assemblage of eugeosynclinal marine sedimentary Northeast of the San Andreas fault, the eugeo and mafic volcanic rocks many thousands of feet synclinal sedimentary and igneous rocks are over thick. The assemblage is composed of graywacke, lain by or are in fault contact with a sequence of claystone, basalt (greenstone), and small lenses of miogeosynclinal marine clastic sedimentary rocks varicolored chert and limestone. These rock types, chiefly of Cretaceous age. This sequence is herein together with the mafic intrusive rocks, form numer designated the Jurassic (?) and Cretaceous marine ous commonly brecciated lenticular masses of all sedimentary sequence. It is the same major unit as sizes in a pervasively sheared "matrix" of dark that referred to by Bailey, Irwin, and Jones (1964, claystone and fragmented graywacke. It is not p. 123-124) as the Great Valley sequence. It was known how or when this assemblage became so in informally named for the Great Valley, west of tensely deformed. This deformation may have re which it is thickest. The term "Great Valley se sulted from severe tectonic movements such as quence" is somewhat inappropriate because the underthrusting, accompanied by the numerous in entire sequence is marine and was not deposited in jections of ultramafic rocks, during or soon after a valley, as this seemingly descriptive term implies. deposition. These violent events appear to have Within the region of figure 2, this sequence is from occurred prior to deposition of the superjacent 7,000 to 10,000 feet thick and is composed of sand Jurassic (?) and Cretaceous marine sedimentary se stone, shale, claystone, and small lenses of conglom quence because it is unaffected by pervasive shear erate. It accumulated probably under open-sea con ing, mixing, and shattering. ditions offshore from a landmass, as suggested by The age within the Mesozoic Era of the Francis scarcity of megafossils and lack of terrestrial beds. can rocks of this region is controversial. Foramini- Three divisions are recognizable: in ascending order, fera from limestone east of Cholame Valley suggest the Gravelly Flat Formation, Hex Claystone, and a middle Cretaceous age (Dickinson, 1966a, p. 718- Panoche Formation (fig. 5). JURASSIC (?) AND CRETACEOUS MARINE SEDIMENTARY SEQUENCE SOUTHEASTERN TCMQI r»o OAM/-C AGE DIABLO RANGE TEMBLOR RANGE Clay shale \ \. (Absent) Sandstone c"^ Clay shale ^^ CRETACEOUSJURASSIC(?)AND SEQUENCEMARINESEDIMENTARY Late _ . - r - PANOCHE FORMATION _ .^^ CRETACEOUS Clay shale ~~~~ -="" s Sandstone ~~~.Z=»- s. Clay shale Conglomerate"^"^-- --._ ? ^-----_____HEX CLAYSTONE Early GRAVELLY FLAT FORMATION o CRETACEOUS EUGEOSYNCLINAL SEDIMENTARY AND FRANCISCAN ROCKS AND SERPENTINE JURASSIC(?) AND IGNEOUS ROCKS FIGURE 5. Jurassic (?) and Cretaceous marine sedimentary sequence in the southeastern part of the Diablo Range and in the Temblor Range. Within the area of figure 2, the age of this se northwest of Coalinga (fig. 1)), this shale unit con quence is Cretaceous. In some places it may be as tains Buchia and was named Gravelly Flat Forma old as latest Jurassic, but no fossils have been tion by Rose and Colburn (1963, p. 41). found to demonstrate this; hence the query after Regional mapping within and northwest of the Jurassic. area of figure 2 reveals that this shale unit is recog nizable in various parts of the Diablo Range and GRAVELLY FLAT FORMATION commonly contains Buchia. It would be appropriate The lowest unit of the Jurassic (?) and Creta to apply one name to this unit throughout its recog ceous marine sedimentary sequence is prominently nizable areal extent, but unfortunately different exposed in the southeastern part of the Diablo names have 'been applied to it in different areas. A Range, where it consists of about 3,000 feet of thin- type exposure should be one that is fossiliferous bedded dark shale containing thin interbeds of and structurally homoclinal with the top and base brown-weathering sandstone. On the southwest exposed; the exposure that best meets these re slope of Orchard Peak, this unit was originally quirements is the one east of Priest Valley. Here referred to by Arnold and Johnson (1910, p. 351, this unit was named by Rose and Colburn (1963, pi. 1) as the Knoxville Formation (of Diller and p. 41) as the Gravelly Flat Formation. Therefore Stanton, 1894), but was mapped as part of the this name is hereby applied to the lowest mappable undifferentiated "Knoxville-Chico rocks." It was commonly Buchia-bearmg predominantly shale unit later named Badger Shale by Marsh (1960, p. 9- of the Jurassic (?) and Cretaceous marine sedi 12). Farther northwest, near Parkfield (10 miles mentary sequence within and northwest of the area northwest of Cholame (fig. 1)), this shale unit was of figure 2. mapped as the lower and middle parts of the Pan- The type section of the Gravelly Flat Formation oche Group by Dickinson (1966a, p. 709-710, pis. 1, was not designated by Rose and Colburn (1963), 2; 1966b, p. 461-462, pi. 1). Still farther northwest, although they mapped the exposure of this unit near Gravelly Flat east of Priest Valley (about 38 southeast of Gravelly Flat. From Gravelly Flat this miles northwest of Cholame or 16 miles west- unit was traced farther northwest by the writer, 8 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA and type section is here designated as the spur other west of Devils Den. In the former exposure extending southwest from Center Peak in the SW*4 it was named Hex Formation by Marsh (1960, p. sec. 12 and NW*4 sec. 13, T. 20 S., R. 12 E., about 6-7). The type locality was designated at Hex Hill, 3 miles northwest of Gravelly Flat (Priest Valley about 6 miles east-southeast of Orchard Peak. This 15' quad.) and about 16 miles west-northwest of name is adopted herein for this unusual formation, Coalinga (fig. 1). There the Gravelly Flat Forma but is modified to Hex Claystone because of its tion is about 2,400 feet thick. It is composed mainly nearly homogeneous claystone lithology. of dark shale, including about 400 feet of brown- The stratigraphic position of the Hex Claystone weathering sandstone in the lowest part, in contact is not definitely known because (1) it is pervasively with serpentine at the base. The shale is conform sheared, (2) it is bounded by faults, (3) it appears ably overlain by a thick conglomerate unit herein to have been injected as a plastic mass between assigned to the base of the Panoche Formation. faults into the Panoche Formation at Hex Hill and According to Rose and Colburn (1963, p. 41) even into Tertiary rocks at Devils Den, and (4) it and D. L. Jones (oral commun., 1970), the lowest is lithologically similar to the claystone or clay shale part of the Gravelly Flat Formation east of Priest of the Panoche Formation, but contains fossils diag Valley contains Buchia piochii, generally considered nostic of a pre-Late Cretaceous age. diagnostic of Late Jurassic (Tithonian) age; the Marsh (1960, p. 6-7) considered his Hex Forma middle part contains Buchia crassa, diagnostic of tion to be of Late Jurassic (?) age on the basis of Early Cretaceous (Valanginian) age; and the upper marine fossils found in the Hex and to be older part contains fossils suggestive of Early Cretaceous than his Badger Shale (Gravelly Flat Formation (Hauterivian) age. of this report), which he assigned to the Early Cre In its exposure east of Priest Valley and also taceous (?). While it is possible that the Hex Clay- within the area of figure 2, the Gravelly Flat Forma stone may have been injected from below the tion is distinguishable from the overlying Panoche Gravelly Flat Formation, this is considered unlikely Formation by its dark-gray to olive-brown color, the because no claystone has been found in that position dark-colored graywacke character of its sandstone in an unfaulted section. Structural evidence revealed interbeds, and a lack of thick light-colored sandstone from mapping on Hex Hill (Dibblee, 1972a) sug beds. Within the area of figure 2 on the south and gests that the Hex Claystone formed by pervasive west slopes of Orchard Peak, where the unit herein shearing of the upper part of the Gravelly Flat referred to the Gravelly Flat Formation was mapped Formation, possibly with some involvement of the by Marsh (1960, p. 9-12, pi. 1) as the Badger Panoche Formation. Shale, the formation is about 3,700 feet thick, it Belemnites and foraminifers from the Hex Clay- contains two layers of tuff or bentonite, and its stone of the Hex Hill area have been considered base is partly if not entirely in fault contact with suggestive of Late Jurassic, Early Cretaceous, or serpentine. North of Orchard Peak this unit is Late Cretaceous ages, and the formation was tenta either depositional on or in fault contact with the tively assigned a Late Jurassic (?) age (Marsh, Franciscan rocks. It yielded no diagnostic fossils 1960, p. 8). Foraminifers from both the Hex Hill in any of these exposures, but is assigned to the and Devils Den exposures are now, however, con Gravelly Flat Formation because it is lithologically sidered strongly suggestive of an Early Cretaceous similar to and occupies the same stratigraphic posi (Valanginian) age (Church, 1968, p. 527). This tion as the type section. It is tentatively considered age is also suggested from Buchia species found at to be of the same age, but because of the absence both exposures (D. L. Jones, oral commun., 1970). of fossils, the Jurassic assignment is queried. PANOCHE FORMATION In the northwestern Temblor Range the Gravelly Flat Formation is lithologically similar to the unit In the southeastern part of the Diablo Range, in the Diablo Range, and no fossils were found. It the Gravelly Flat Formation is overlain by as much may be over 5,000 feet thick, but its contact with as 7,500 feet of interbedded concretion-rich light- shale of the overlying Panoche Formation is only colored sandstone and dark-gray clay shale or clay- arbitrarily placed at the lowest abundantly inter- stone of Late Cretaceous age. The contact with the bedded sandstones. underlying Gravelly Flat Formation is gradational, but in places it is marked by lenses of conglomerate HEX CLAYSTONE or sandstone. Pervasively sheared gray claystone is exposed in These Upper Cretaceous strata were referred by two places, one southeast of Orchard Peak, the Arnold and Johnson (1910, p. 35-37, pi. 1) to the UPPER CRETACEOUS AND LOWER TERTIARY MARINE SEDIMENTARY SEQUENCE Chico Formation (of Gabb, 1869), but were mapped 1966b, p. 464, Table Mountain area; D. L. Jones, as the major part of their undifferentiated "Knox- oral commun., 1966, Cedar Creek area of northwest ville-Chico rocks." In the Orchard Peak area south Temblor Range). In the Orchard Peak area, the west of McLure Valley, these strata were divided upper half of the Panoche Formation is inferred by Marsh (1960, p. 12-29, pis. 1, 2) into eight local from megafossils and microfossils to be mainly units mapped as formations, including the upper within the Campanian Stage, ranging into the San- most claystone unit that he referred to the Moreno tonian and possibly into the lower Maestrichtian Formation of Anderson and Pack (1915). The Stages (Marsh, 1960, p. 25, 28, 29). West of Reef names Marsh applied to these units are not adopted Ridge the lowest shale unit of the Panoche Forma herein because the units are not recognizable out tion, about 7 miles southwest of Avenal, yielded an side that area. Farther northwest, all the Creta ammonite (found by Paul Enos) considered diag ceous marine sedimentary sequence was referred nostic of the Turonian Stage (D. L. Jones, oral by Dickinson (1966a, p. 709-710) to the Panoche commun., 1965). Group. This series of strata, of Late Cretaceous age, is UPPER CRETACEOUS AND LOWER assigned to the Panoche Formation because it in TERTIARY MARINE SEDIMENTARY cludes the major part of the series mapped as the SEQUENCE Panoche Formation by Anderson and Pack (1915) DEFINITION and is lithologically distinct from the part assigned Southwest of the San Andreas fault, the crystal to the Gravelly Flat Formation. It is most practical line basement of the Salinia block is overlain by a to differentiate the Panoche Formation on the basis very thick sequence of miogeosynclinal marine clastic of lithology into units that are predominantly sand sedimentary rocks that ranges in age from very stone, units that are predominantly shale or clay- Late Cretaceous through Paleocene to middle Eo stone, and units that are predominantly conglom cene. It is designated herein as the Upper Creta erate, as shown in figure 5. No names are applied ceous and lower Tertiary marine sedimentary se herein because the lateral extent of these units is quence. It is extensively exposed in the La Panza very limited. Range and the Sierra Madre Mountains, where it The uppermost clay shale unit crops out on the is herein designated as marine clastic sedimentary west and south sides of McLure Valley, where it is rocks; a small part is exposed at the southeast end about 900 feet thick and is overlain unconform- of the Caliente Range, where it was called Pattiway ably by Tertiary formations. On the south side of Formation. the valley, this clay shale unit was referred by This thick sequence and its paleogeographic im Marsh (1960, p. 28-29, pi. 1) to the Moreno Forma plications were described by Chipping (1972), who tion of Anderson and Pack (1915, p. 46-47) on the divided it into several unnamed lithogenetic units. basis of similar lithology and microfaunal correla tion. This correlation is doubtful, however, because MARINE CLASTIC SEDIMENTARY ROCKS the Moreno Formation, of latest Cretaceous and The marine clastic sedimentary rocks are a mo Paleocene(?) age, overlies the Panoche Formation notonous, continuously deposited series, as much as north of Coalinga but is overlapped by Tertiary 30,000 feet thick, of interbedded arkosic sandstone, formations south of Coalinga; moreover, it is not siltstone, clay shale, and granitic conglomerate. known to be present within the area of figure 2, These strata appear to be deltaic deposits derived either on the surface or in the subsurface (R. L. from rapid erosion of a nearby granitic terrane and Pierce, oral commun., 1968). deposited in a shallow sea. This thick series is not In the northwestern Temblor Range, only the named nor differentiated into formations or mem lowest 2,000 feet of the Panoche Formation is ex bers because it contains no persistent distinct litho- posed. It lies unconformably below Tertiary forma logic units other than a basal conglomerate as thick tions, and its contact with the underlying Gravelly as 2,000 feet which overlies granitic basement in Flat Formation is gradational and arbitrarily the La Panza Range. The marine clastic sedimentary Jocated. rocks, together with the granitic basement exposed The Panoche Formation within the area of fig in the La Panza Range, are overlain unconformably ure 2 contains scattered megafossils and micro- by the middle Tertiary sedimentary sequence. fossils diagnostic of Late Cretaceous age (Cam- This series of marine clastic sedimentary rocks panian and Maestrichtian Stages) (Marsh, 1960, rarely contains fossils. This sequence was formerly p. 16, 21, 24, 25, 28, Orchard Peak area; Dickinson, thought to be of Late Cretaceous age (Eaton and 10 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA others, 1941, p. 213-214, fig. 3; Hill and others, or presumably of late Eocene age, whereas part of 1958, p. 2997; Jennings, 1958); however, a few fos the sequence described here is older. This lower sils diagnostic of Late Cretaceous age were found in Tertiary sequence is composed of the units shown the lowest 6,000 feet of this sequence in the La in figure 6. Panza Range from 21/& to 7 miles northwest of Pozo and in the basal 1,000 feet near Deadman LODO(?) FORMATION Flat, 24 miles southeast of Pozo. A few mollusks On Media Agua Creek, in the Temblor Range, and foraminifers considered to be of Paleocene age about 280 feet of rocks, predominantly clay shale, were found stratigraphically higher a few miles forms an interval between shale of the Panoche southeast of Pozo, and orbitoidal foraminifers diag Formation and the Point of Rocks Sandstone. On nostic of early to middle Eocene age were found the basis of microfaunas, this interval was corre still higher in the section in the Sierra Madre lated with and assigned by Mallory (1959, figs. Mountains (Vedder and Brown, 1968, p. 248-249). 3, 7) to the Lodo Formation of White (1938) (type Just beyond the southeast border of figure 2, the locality about 35 miles northwest of Coalinga) of highest part of this series yielded mollusks diag Paleocene and early Eocene age. Mallory divided nostic of middle Eocene age (Vedder and Brown, this interval into three units: lower, middle and 1968, p. 249-251). upper Lodo. At the southeast end of the Caliente Range (T. 10 The lower Lodo, as indicated by Mallory (1959, N., R. 25 W.), is exposed about 3,000 feet of marine p. 25-26, 30-31, 34, figs. 3, 7), is about 160 feet clastic sedimentary rocks which there were named thick at Media Agua Creek and is composed of soft the Pattiway Formation by Hill, Carlson, and Dib- clay shale. On the basis of microfaunas he assigned blee (1958, p. 2977). This name is adopted herein this unit to his Ynezian and Bulitian Stages, Paleo for this unit but only for this exposure, and others cene, with the exception of the uppermost 20 feet, beyond the southeast border of figure 2. In these which, together with the overlying "sandstone reef" exposures, the Pattiway Formation is composed of (his middle Lodo), he designated as his type Penu- light-gray sandstone, gray silty shale, and a few tian Stage, early Eocene. These stages assigned to thin conglomerate lenses. It is unconformably over this 160-foot-thick clay shale unit correlate it with lain by the Simmler Formation, and the base is not the type Lodo Formation, and its assignment to that exposed. In the Caliente Range, the Pattiway For formation is tentatively adopted. From Media Agua mation yielded mollusks and foraminifers considered Creek this clay shale unit appears to extend south to be of Paleocene age (Vedder and Repenning, eastward along strike for an unknown distance, 1965). through poor exposures, possibly as far as Carneros Creek or Salt Creek. Northwest of Media Agua LOWER TERTIARY MARINE SEDIMENTARY Creek it laps out. SEQUENCE Mallory (1959, p. 28, 37, fig. 7) suggested that a similar shale unit underlying the Avenal ("Ma- DEFINITION bury") Sandstone in the Devils Den area may be Northeast of the San Andreas fault, the Juras of Paleocene and early Eocene ages, and he assigned sic (?) and Cretaceous marine sedimentary sequence it to the Lodo Formation. Foraminifera suggestive is overlain unconformably or disconformably by a of those ages have been reported from a thin shale marine sedimentary sequence of early Tertiary age. unit above the Panoche Formation from several It is designated herein as the lower Tertiary ma wells in the Devils Den area (H. C. Wagner and rine sedimentary sequence. It is as thick as 3,000 others, unpub. data). feet and is composed of moderately well defined Mallory's middle Lodo at Media Agua Creek is units of sandstone and clay shale of Eocene age; it considered to be the Avenal Sandstone, and his includes at the top a thin unit of early Oligocene upper Lodo the Gredal Shale Member of the Kreyen- age exposed only at Devils Den. hagen Shale, for reasons discussed under "Avenal All but the thin top unit of this sequence was Sandstone." Their assignment to the Lodo Forma formerly referred to the Tejon Formation (of Gabb, tion is therefore not adopted. 1869, p. XIII and p. 129, footnote) by Arnold and Anderson (1910, p. 67-70, pi. 1), Arnold and John AVENAL SANDSTONE son (1910, p. 38-39, pi. 1), and Curran (1943). In the Reef Ridge area, northwest of McLure Such a name might be appropriate, but as now used Valley, the basal Tertiary sandstone unit was named it is generally applied to strata that are definitely Avenal Sandstone by Anderson (1905, p. 164, pi. 34, LOWER TERTIARY MARINE SEDIMENTARY SEQUENCE 11 SOUTHEASTERN REEF RIDGE DEVILS DEN TEMBLOR AGE STAGE DIABLO RANGE AREA AREA RANGE Oligo- Wagon Wheel Refugian cene Formation (Absent) Absent Welcome Shale Member CD CO 0) ro Narizian -Eg "" Point of Point of io « Rocks Kreyenhagen Rocks E a Shale CD Sandstone Sandstone ro > CD O O 0} *-> L±J L_ C V <" « E -J w CD Ulatisian i (Absent?) Gredal Shale Member ./ Avenal Sandstone J^ (Absent) FIGURE 6. Lower Tertiary marine sedimentary sequence in part of the Diablo Range between McLure and Cholame Valleys and in the Temblor Range. Unconformity indicated by wavy line. fig. 1) for Avenal wells in Big Tar Canyon, 6 miles In the Diablo Range west of McLure Valley, this southwest of Avenal (fig. 2). This sandstone was basal sandstone is as thick as 400 feet and was assigned to the Domengine Formation (of Ander- called Acebedo Sandstone by Dickinson (1963, p. son, 1905, north of Coalinga) by Clark (1929, p. 48-52). This sandstone contains <(Spiroglyphus" 216) and Gester and Galloway (1933, p. 1167,1184). and orbitoid Foraminifera, and according to Mal The Avenal Sandstone, which contains orbitoid lory (1959, p. 50-51), it is slightly older than the Foraminifera and abundant mollusks, was mapped type Avenal Sandstone and was assigned by him and described in detail by Stewart (1946, p. 89-94, to the Ulatisian or Penutian Stage, middle or lower pi. 1), who adopted the name and suggested its Eocene. correlation with the Domengine Formation, which In the Devils Den area, the lowest Tertiary sand is very similar and is probably the same unit. The stone unit, as thick as 200 feet, contains "Spiro- Avenal Sandstone is from 300 to 500 feet thick and glyphus" (Rotularia) and was named Mabury fine grained, and it contains abundant mollusks Sandstone by Van Couvering and Alien (1943, p. assigned to the middle Eocene (Stewart, 1946, p. 496-500). Mallory (1959, p. 37, fig. 7) assigned 92-94). It was questionably assigned to the Ulatisian this sandstone to the Lodo Formation and to his Stage, middle Eocene, by Mallory (1959, p. 51, Penutian Stage, lower Eocene. fig. 7). In the Temblor Range between Media Agua and In areas south and southeast of McLure Valley, Carneros Creeks, the lowest Tertiary sandstone unit the basal Tertiary sandstone discussed in the next forms a lens as thick as 300 feet. It is underlain by three paragraphs is herein included in the Avenal clay shale of the Lodo Formation and is overlain Sandstone because of generally similar lithology by the Gredal Shale Member of the Kreyenhagen and probably similar stratigraphic position. Local Shale. According to Durham (1942, p. 503-510), names have been applied to this sandstone because this sandstone contains (in NE^4SE^4 sec- 28, T. of uncertainty of its correlation with the type Ave 28 S., R. 19 E., east of Media Agua Creek) mollusks nal Sandstone. and corals referred to the Domengine Stage, middle 12 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA Eocene. However, at Media Agua Creek, where the that the upper part may be as young as Oligocene sandstone unit is only 25 feet thick, Mallory (1959, (Refugian). The lowest 50-110 feet of the Kreyen p. 24, 34, fig. 7) designated the sandstone (his mid hagen Shale is greenish claystone which was named dle Lodo) and 20 feet of the underlying shale as his the Canoas Siltstone Member by Cushman and Sieg type Penutian Stage, lower Eocene; he correlated fus (1942, p. 390-391) and which contains a foram- the sandstone, which there contains "Spiroglyphus" iniferal fauna ("Canoas Fauna") to which they and orbitoid foraminifers, with the Mabury Sand assigned a middle Eocene age. Mallory (1959, p. 51, stone of Devils Den and assigned both to the Lodo 71) suggested that this fauna may belong to his Formation. Ulatisian Stage, middle Eocene, but it is not cer This assignment is not adopted because at Media tainly diagnostic. Agua Creek this 25-foot-thick "sandstone reef" is In the Devils Den area the Kreyenhagen Shale is overlain by about 90 feet of clay shale which Mal separated into two units of clayey shale by the lory (1959, p. 30, fig. 3, 7) designated as upper Point of Rocks Sandstone (fig. 6). The lower unit, Lodo but which he assigned to his Ulatisian Stage, as thick as 700 feet, was named the Gredal Forma middle Eocene. This assignment would correlate tion by Van Couvering and Alien (1943, p. 496- this shale with the Gredal Shale Member of the 500). This same unit was designated as the Gredal Kreyenhagen Shale. The underlying "sandstone Member of the Lodo Formation and assigned to the reef" is therefore probably the same unit as the Ulatisian Stage, middle Eocene, by Mallory (1959, Avenal Sandstone, to which it is assigned. p. 45, 51, fig. 7), but it was mapped as the Canoas Although there is some doubt as to exact correla Siltstone Member of the Kreyenhagen Shale by tion, the Acebedo Sandstone west of McLure Valley, Marsh (1960, p. 31, pi. 1). Because this unit is much Mabury Sandstone of Devils Den, and the sandstone thicker than the type Canoas Siltstone Member of at Media Agua Creek are herein assigned to the Reef Ridge (too thin to show at the map scale), Avenal Sandstone because in each area they are of with which it is correlated by petroleum geologists, generally similar lithology and form the basal trans- the unit at Devils Den is herein adopted as the gressive sandstone unit of the lower Tertiary marine Gredal Shale Member of the Kreyenhagen Shale. sedimentary sequence; thus they appear to be the The type section of this member is designated as same unit. Therefore the local names Acebedo and the section exposed in NE*4 sec. 10, T. 26 S., R. Mabury are not formally adopted. The Avenal Sand 18 E., 4 miles south of Devils Den, where it consists stone, as herein mapped, is presumably in the Do- of about 750 feet of gray clayey shale with local mengine molluscan age and Fenutian and Ulatisian occurrences of green and red clay, overlies the Ave Stages, early and middle Eocene. nal ("Mabury") Sandstone, and is overlain by the KREYENHAGEN SHALE Point of Rocks Sandstone. The clay shale and claystone facies of the lower In the northwestern Temblor Range, the Gredal Tertiary marine sedimentary sequence is promi Shale Member of the Kreyenhagen Shale is exposed nently exposed in the Reef Ridge area north of south of Cedar Creek and at Media Agua Creek McLure Valley. It was named Kreyenhagen Shale (fig. 9). In the former area, it is several hundred for Kreyenhagen wells at Canoas Creek (7 miles feet thick and consists of gray, green, and red clay- west of Avenal), the type locality, by Anderson stone that unconformably overlies the Gravelly Flat (1905, p. 163-168). This name was not used by Formation. At Media Agua Creek, it overlies the Arnold and Anderson (1910, p. 58-70) but was Avenal (?) Sandstone and is overlain by the Point adopted by Cushman and Siegfus (1942), who de of Rocks Sandstone, as at Devils Den; it is about scribed the sections exposed at Canoas and Garza 90 feet thick and is the same unit as the upper Lodo Creeks (7 miles west of Avenal) and by Stewart of Mallory (1959, p. 24, 45, figs. 3, 7), which he (1946, p. 95, pi. 1), who described and mapped the assigned to his Ulatisian Stage, middle Eocene. formation in detail. The upper unit of the Kreyenhagen Shale in the In the Reef Ridge area the Kreyenhagen Shale Devils Den area is composed of about 600 feet of is from 950 to 1,250 feet thick, consists of gray clayey shale that overlies the Point of Rocks Sand clayey to silty shale, overlies the Avenal Sandstone, stone and is overlain by the Wagonwheel Formation. and is unconformably overlain by the Temblor This shale unit was named Welcome Formation by Sandstone. The major part of the Kreyenhagen Van Couvering and Alien (1943, p. 496-500). This Shale contains foraminifers diagnostic of the Nari- unit is herein adopted as the Welcome Shale Mem zian Stage, late Eocene (Mallory, 1959, p. 71, fig. 7). ber of the Kreyenhagen Shale, with the type section Cushman and Siegfus (1942, p. 395-397) suggested designated as Welcome Valley (SE^4 sec. 35, T. 25 MIDDLE TERTIARY SEDIMENTARY SEQUENCE 13 S., R. 18 E., NE*4NE14 sec. 2 and NWVi sec. 1, mapped as Oligocene (?) rocks by Arnold and John T. 26 S., R. 18 E.), just south of Devils Den. This son (1910, p. 40). Johnson (1909, p. 63) had pre unit is poorly and incompletely exposed; it is con viously named this unit the Wagonwheel Formation cealed by alluvium to the southeast and is over for exposures near Wagonwheel Mountain, 2 miles lapped by the Temblor Formation to the northwest. south of Devils Den, and had tentatively assigned It forms the upper part of the type Narizian Stage, it to the Oligocene. This name was used by Van upper Eocene, of Mallory (1959, p. 55-56), al Couvering and Alien (1943, fig. 213) and is adopted though foraminifers of the Refugian Stage have herein. Atwill (1935, p. 1207) correlated this unit been reported from the uppermost part of this with his Tumey Formation north of Coalinga. shale unit by Smith (1956, p. 77-78) and Mallory The Wagonwheel Formation and its foramini- (1959, p. 71). feral fauna were described and discussed in detail On the basis of the foregoing evidence, the Gredal by Smith (1956). He assigned the formation to the Shale Member of the Kreyenhagen Shale is assigned Refugian Stage of early Oligocene age and indicated to the Ulatisian Stage, middle Eocene, and the Wel that it lies conformably on the Kreyenhagen Shale come Shale Member is assigned to the Narizian and disconformably below the Temblor Formation. Stage, upper Eocene, with the upper part possibly Because of these stratigraphic relationships, this extending into the Refugian Stage, early Oligocene. unit, which is the only one wholly assigned to the POINT OF ROCKS SANDSTONE Refugian Stage within this region, is placed arbi The sandstone of the Eocene sedimentary sequence trarily at the top of the lower Tertiary marine sedi is prominently exposed in the northwest part of the mentary sequence, rather than in the middle Ter Temblor Range, where it is as much as 2,000 feet tiary sedimentary sequence. thick, near Devils Den where it is about 2,350 feet MIDDLE TERTIARY SEDIMENTARY thick, and in the Diablo Range, where it is as much SEQUENCE as 1,250 feet thick. In the Devils Den area, it was DEFINITION named Point of Rocks Sandstone, for Point of Rocks The middle Tertiary sedimentary sequence is ex (Si/2 sec. 2, T. 26 S., R. 18 E.), 3 miles south of tensive on both sides of the San Andreas fault. It Devils Den, by Van Couvering and Alien (1943, lies unconformably on the older rock units in most p. 496-500). This name is adopted herein. In the areas and is lithologically more variable than the Reef Ridge area, this sandstone either is missing other sedimentary sequences. It represents a com or may be represented by a sandstone lens as thick plete sedimentary cycle of transgression, inunda as 30 feet about 100 feet above the base of the tion, and regression. This sequence is mainly of Kreyenhagen Shale (Dickinson, 1966a, p. 711). Miocene age, but it is in part Oligocene and possibly The Point of Rocks Sandstone rarely contains in part Pliocene. fossils. "Characteristic Tejon fossils" were reported Southwest of the San Andreas fault, this sequence but not listed from the Point of Rocks area by is as thick as 10,000 feet in the central part of the Arnold and Johnson (1910, p. 38). At Devils Den, Caliente Range and probably equally as thick under the Point of Rocks Sandstone, with the possible the Carrizo Plain. Within a few miles the whole exception of the lowest 75 feet, was designated as sequence thins to the northwest, southwest, and the type Narizian Stage, upper Eocene, by Mallory southeast to about 2,500 feet or less, with a few (1959, p. 55-56). Foraminifers diagnostic of the local unconformities within it. The lowest unit of Narizian Stage were obtained from thin shale beds this sequence is terrestrial, the remainder is marine; in this sandstone at Devils Den and also at Media much of this marine part grades laterally northeast Agua Creek by Mallory (1959, p. 56). At Devils ward into terrestrial deposits apparently derived Den, shale interbeds in the lowest 75 feet of the from a granitic terrane that existed northeast of Point of Rocks Sandstone contain foraminifers as the San Andreas fault in middle Tertiary time. signed by Mallory (1959, p. 57) to the Ulatisian Most of the marine facies is sandstone and some Stage. The basal part of the Point of Rocks Sand argillaceous sediments, but the middle part in areas stone is thereby assigned to the Ulatisian Stage, distant from the San Andreas fault is mostly sili middle Eocene, and the major part to the Narizian ceous shale. Basaltic intrusions and lava flows occur Stage, upper Eocene. in both the terrestrial and marine facies in the WAGONWHEEL FORMATION Caliente Range. This sequence unconformably over In the Devils Den area, a basal marine sandstone lies the Upper Cretaceous and lower Tertiary marine and a clayey shale unit, about 500 feet thick, were sedimentary sequence, overlapping and truncating 495-417 O - 73 - 3 14 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA CALIENTE RANGE, LLl SIERRA MADRE MOUN" STAGE rAINS CARRIZO PLAIN(?), AND NORTHEAST.^ AND LA PANZA RAN GE RED HILLS AREA SAN"FA MARGARITA FORMATION ^^^<^___Basa\i_^> Mohnian (sandstone) "r"--.,. f - ^-^ /Basalt Luisian I Whiterock Bluff Shale J> <^ <---"* 1 Member -= - ' -.--" BRANCH ""^ ->. ~3sasalt MONTEREY ^.--^ ^--> ,v,v/ ---J1 _==^pa* -7= =~ % CALIENTE Basalt 7 «£ FORMATION < Painted Rock ^ Saucesian Sandstone __- ^^ ^^^ S VAQU EROS Member <^^ -^T ^> N FORM ATION - =._"""" ^--::^" ^^-^ ^" Soda Lake Shale Member J^;*~ ^>- Oligocene \ * ' Zemorrian 1 Mostly *^ Quail Canyon Sandstone Member7 (Absent) \^ conglom- ^fMMLER FORMATION Mostly ^x erate ~~^ x v^ <^ sandstone UPPER CRETACEOUS AND LOWER TERTIARY MARINE SEDIMENTARY SEQUENCE, AND CRYSTALLINE ROCKS FIGURE 7. Lithologic units of the middle Tertiary sedimentary sequence southwest of the San Andreas fault from Cho- lame to Cuyama. Caliente and Simmler Formations are terrestrial; all other units marine. Unconformity indicated by wavy line. it from south to north onto the crystalline rocks. middle Tertiary sedimentary sequence northeast of The lithologic units that make up the middle Ter the San Andreas fault are shown in figure 8. The tiary sedimentary sequence southwest of the San stratigraphic units of this sequence shown in fig Andreas fault are shown in figure 7. ures 7 and 8 are discussed in the following sections. Northeast of the San Andreas fault, this sequence is virtually all marine. It attains its greatest thick SIMMLER FORMATION ness, one of the greatest in California, in the south Southwest of the San Andreas fault, the basal eastern Temblor Range, where it is as thick as unit of the middle Tertiary sedimentary sequence 15,000 feet. In this area and adjacent parts of San is composed of terrestrial red to gray conglomerate, Joaquin Valley, most of it accumulated under sandstone, and siltstone. It was named the Simmler bathyal and abyssal conditions (Bandy and Arnal, Formation by Hill, Carlson, and Dibblee (1958, p. 1969, p. 794, 814). Northwestward, this sequence 2981-2983, fig. 3). The name is adopted herein. This gradually thins to as little as 700 feet in the Diablo formation lies unconformably on and overlaps the Range and accumulated under shallower water. The Upper Cretaceous and lower Tertiary marine sedi lower part is chiefly sandstone and argillaceous mentary sequence from south to north onto the deposits, the upper part mainly siliceous shale. In underlying crystalline rocks. It is conformably over the southeastern Temblor Range and adjacent parts lain by the Vaqueros Formation. of the San Joaquin Valley, this sequence lies dis- In the Caliente Range, the southeastern part of conformably(?) on the lower Tertiary marine sedi which includes the type section from 4 to 5 miles mentary sequence, but in the northwestern Temblor northeast of Cuyama (Hill and others, 1958, p. Range and Diablo Range it becomes unconformable 2981), the Simmler Formation is about 3,000 feet on this and the older sequences, with increasing dis thick and consists of hard red and greenish-gray cordance westward toward the San Andreas fault. well-bedded sandstone, siltstone, and local basal In a few places local unconformities occur within conglomerate. Its red and greenish colors and lack this sequence. The lithologic units that make up the of marine fossils suggest that this formation is MIDDLE TERTIARY SEDIMENTARY SEQUENCE 15 SOUTHEASTERN STAGE SOUTHEASTERN NORTHWESTERN DIABLO RANGE TEMBLOR RANGE TEMBLOR RANGE BITTERWATER REEF RIDGE SHALE (Absent or not exposed) CREEK SHALE (Absent?) SANTA MARGARITA Belridge Diatomite Member FORMATION Mohnian J^pnglpmerate) Sandstone lenses< McLure Shale Member SHALE Luisian Devilwater Shale Member Shale and (Absent) Gould Shale Member I sandstone Relizian Sauce- Sandstone sian (Absent) TEMBLOR FORMATION Zemor- Conglom o Pre-Ze- LOWER TERTIARY MARINE SEDIMENTARY SEQUENCE AND OLDER ROCKS morrian FIGURE 8. Lithologic units of the middle Tertiary sedimentary sequence northeast of the San Andreas fault from Avenal to Maricopa. All units are marine. Unconformities indicated by wavy lines. For named local units of Temblor Forma tion, see table 2 and figures 10 and 11. entirely terrestrial and may contain some lacustrine Formation and unconformable relationship to the beds. underlying sequence suggest that it is most likely In the La Panza Range and the vicinity of Cuyama Oligocene in age. It is probably mainly in the Ze Gorge, the Simmler Formation consists of red and morrian Stage, late Oligocene, and possibly in part gray coarse conglomerate and sandstone. It is as in the Refugian Stage, early Oligocene. The Simmler thick as 3,400 feet in Cuyama Gorge, but is much Formation is probably correlative with the Berry thinner in the La Panza Range. This conglomerate Formation (of Thorup, 1943) of Salinas Valley and was mapped as the Redrock Canyon Member of the with the Sespe Formation (of Watts, 1897) of the Santa Margarita Formation by English (1916, p. Santa Ynez Mountains and Ventura basin on the 202); as the nonmarine Vaqueros Formation by basis of similar lithology and stratigraphic position. Eaton, Grant, and Alien (1941, p. 217); as the Sespe Formation by Clements (1950); and as Oligo- VAQUEROS AND TEMBLOR FORMATIONS cene(?) red beds by Vedder and Brown (1968, p. REVIEW OF NOMENCLATURE 252-253). It was referred to the Simmler Forma Marine sandstone and argillaceous sediments, tion by Hill, Carlson, and Dibblee (1958, fig. 3) commonly assigned early and middle Miocene ages because its stratigraphic position is the same as but now considered to be late Oligocene to middle that of Simmler Formation in the Caliente Range Miocene, form all or much of the lower part of the and it was presumed to be continuous with that middle Tertiary sedimentary sequence on both sides formation. It is, however, much coarser and con of the San Andreas fault. Two names, Vaqueros tains much sandstone detritus. and Temblor, have been applied to this marine unit, The Simmler Formation is unfossiliferous, ex and both have been in common usage for more than cept for sparse plant remains and bone fragments. 60 years. Its possible age range is from late Eocene to early The name Vaqueros was applied by Hamlin Miocene. Its conformable relationship to the over (1904) when he mapped sandstone exposures of lying .beds of Zemorrian Stage of the Vaqueros this unit about 10 miles west of King City. This 16 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA name was also used by Fairbanks (1904) for equiva the lower faunal zone in the Caliente Range (Eaton, lent rocks near Paso Robles. Anderson (1905) ap 1939, pi. IV; Repenning and Vedder, 1961, p. C237), plied the name "Temblor beds" to what was later the faunal assemblages are distinct. Loel and Corey found to be essentially a stratigraphically equivalent (1932, p. 45-50), Wimrarth (1938, p. 2127, 2234- unit in the Temblor Range. Application of both these 2235), Eaton (1939, p. 259-266, pi. IV), Eaton, names followed, as shown on table 1. In early years, Grant, and Alien (1941, p. 216-224), and Woodring, Stewart, and Richards (1940, p. 129) applied the TABLE 1. Names applied by other investigators to strata term Vaqueros to strata that contain fossils of the herein assigned to the Vagueros and Temblor Formations lower faunal zone because these fossils occur in the of map region of figure 2 type Vaqueros Formation (of Hamlin, 1904) and Southwest of Northeast of applied the term Temblor to strata that contain San Andreas fault San Andreas fault Investigators fossils of the upper faunal zone because these fossils Vaqueros Formation ______Fairbanks (1904) Temblor beds ______-Anderson (1905, p. occur in most of the type Temblor Formation (of 170-172; 1908, p. 18-20). Anderson, 1905). These names were also applied to Vaqueros Formation Arnold and Anderson (1908, p. 31-35,pl. 1; the faunal zones or "ages," when the lower faunal 1910. p. 80-88, pi. 1). _,_do______Arnold and Johnson zone became known as "Vaqueros age" and the (1910, p. 42-51, pi. 1). Temblor Group _ Anderson and Martin, upper zone as "Temblor age" (Weaver and others, (1914, p. 37-44, pi. 10). 1944, chart 11; Corey, 1954, chap. Ill, fig. 9), but Vaqueros Formation __Anderson and Pack (1915 p. 80-87). these molluscan "ages" were never defined. Vaqueros Formation.--______English (1916, p. 198- 201, pi. XIX). Studies of the foraminiferal faunas in the "lower Vaqueros Formation English (1921, p. 13 21, Pi. 1). Miocene" strata by Kleinpell (1938, p. 152-155, fig. Do Loel and Corey (1932, p. 45-50). 4) indicate that "Vaqueros age" corresponds roughly Temblor1 and Vaqueros1 ______Eaton (1939, p. 261-266, pi. IV); Eaton, Grant to his Zemorrian Stage; "Temblor age" to his late and Alien (1941, p. 216-230, fig. 3). Saucesian Relizian and Luisian Stages; and a "tran Temblor Formation ___Kleinpell (1938, p. 104- 107, pi. 6). sition zone" to his early Saucesian Stage. Temblor Sandstone _ Woodring, Stewart, and Richards (1940, p. Differentiating the "lower Miocene" marine strata 129-144, pi. 51). Temblor-Vaqueros ____Simonson and Kruegrer into the Vaqueros and Temblor Formations on the (1942, p. 1613-1616). Temblor Formation _ Curran (1943, p. 1365 basis of their faunal content seemed appropriate, 1369). Escudo and Hannah Van Couvering and but was impractical because (1) generally the lith- Formations Alien (1943, p. 496- 500). ology does not change within these strata, (2) no Vaqueros Sandstone _ Bramlette and Daviess (1944). definite boundary separates the two faunal "ages," Temblor Formation ___Stewart (1946, p. 97-103, pi. 9). and (3) in many exposures fossils are scarce or do -Heikkila and MacLeod (1951, p. 5, 7-11, pi. lacking. Even in the most fossiliferous and complete 1). ___do______Marsh (1960, p. 31-32, section in the Caliente Range, the formations could Pi. 1). Vaqueros Formation _ _ Hill, Carlson, and not be differentiated with certainty on this basis Dibblee (1958, p. by Hill, Carlson, and Dibblee (1958) or by Vedder 2983-2987). Do______Temblor-Vaqueros Dibblee (1962, p. 9-10); and Repenning (1965), although the faunizones Formation. Fletcher (1962, p. 17). could be recognized. Do ______-__-___-- Vedder and Repenning (1965). It is here proposed that in all areas southwest Temblor-Vaqueros Dickinson (1966a, p. Formation. 711-713, pi. 2). of the San Andreas fault the name Vaqueros Forma Temblor Formation ___Foss and Blaisdell (1968, p. 38-41). ___ tion be applied to this whole stratigraphic unit and 1 Used in the time-stratigraphic sense. that in all areas northeast of this fault the name Temblor Formation be applied. Because of their "Vaqueros" was used by geologists of the U.S. long-established usage in this manner (fig. 4), both Geological Survey, and "Temblor" by F. M. Ander names are best retained with the fault as an arbi son of the California Academy of Sciences. trary boundary. Paleontological studies of the molluscan and echi- In the field this marine unit, deposited under a noid faunas from the "lower Miocene" strata by transgressing sea, is diff erentiable into two principal Wiedey (1928, p. 104-107) and by Loel and Corey lithologic types or fades: (1) sandstone and (2) (1932, p. 45-50) established the presence of two argillaceous sedimentary rocks variously called faunal zones, namely a lower or Turritella inezana mudstone, siltstone, claystone, clay shale, silty shale, zone and an upper or Turritelta ocoyana zone. Al and shale. Where these two types are interbedded, though some confusion resulted when it was found the facies unit is designated by the predominant that Turritella ocoyana ranges downward far into rock type. In some areas, especially near oil fields, MIDDLE TERTIARY SEDIMENTARY SEQUENCE 17 the parts of these facies that form local strati- designated by Hill, Carlson, and Dibblee (1958, p. graphic units have been named and described in 2984) for the Soda Lake Sandstone Member. It many publications as members. conformably overlies red beds of the Simmler For The age of the Vaqueros and Temblor Formations mation and was described by Hill, Carlson, and is generally regarded as early Miocene or Oligocene Dibblee (1958, p. 2984) as follows: and Miocene (Weaver and others, 1944, chap. 11). The sandstone in the type section attains a maximum thick Within the region of figure 2 both formations are ness of 300 feet. It thins westward by a probable gradation into Soda Lake shale and toward the southeast it becomes mainly within the Zemorrian and Saucesian Stages, undifferentiated from the overlying Painted Rock sandstone and locally the uppermost parts include the lowest (T. 10 N., R. 25 W.). At its type locality * * * the Soda part of the Relizian Stage, middle Miocene. The Lake sandstone is characteristically gray-white, weathering Zemorrian Stage is now considered equivalent to to light buff, massively bedded, fine to medium grained, late Oligocene age and the Saucesian Stage to the well sorted, and very firmly indurated. It is commonly early Miocene (Bandy and Arnal, 1969, p. 786). If cross-bedded with fore-set beds dipping in a westerly di rection. this correlation is accepted, then the Vaqueros and This sandstone member contains Pecten mag Temblor Formations are late Oligocene to middle nolia and other forms diagnostic of "Vaqueros age" Miocene in age. (J. G. Vedder, oral commun., 1968), Oligocene. According to R. L. Pierce (oral commun., 1970), VAQUEROS FORMATION this sandstone member is probably correlative with Southwest of the San Andreas fault the Vaqueros the Agua Sandstone Member of the Temblor For Formation is thickest, 7,000 feet, in the central and mation, and with the Vaqueros Sandstone of the northwestern parts of the Caliente Range and pos Santa Ynez Mountains. The Quail Canyon Sand sibly under the Carrizo Plain. It thins southeast stone Member is assigned to the late Zemorrian ward to about 1,000 feet at the southeast end of the Stage, late Oligocene, on the basis of the foregoing range, in part by intertonguing of its upper part evidence. into the terrestrial Caliente Formation. To the northwest, west, and southwest, this formation thins SODA LAKE SHALE MEMBER to about 1,000 feet or less under Salinas Valley and The Soda Lake Shale Member consists of dark- in the La Panza Range. In western Cuyama Valley gray silty clay shale, claystone, and siltstone. The and in the Sierra Madre Mountains, it is either type section is in the northwestern Caliente Range absent or very thin. (NE14 sec. 6, T. 31 S., R. 19 E., and extreme SE14 In areas other than the Caliente Range, the sec. 31, T. 30 S., R. 19 E.), 3 miles west of the Vaqueros Formation is mostly all sandstone and is north end of Soda Lake (Hill and others, 1958, p. undivided. In the Caliente Range, this formation 2983, 2985). There, it is about 1,200 feet thick and was divided by Hill, Carlson, and Dibblee (1958, contains a prominent bed of chert just below the p. 2983-2988) into a local basal unit called the Soda middle. It contains foraminifers diagnostic of the Lake Sandstone Member, a lower unit called Soda Zemorrian Stage (late Oligocene) below that chert Lake Shale Member, and an upper unit called bed and foraminifers of the Saucesian Stage (early Painted Rock Sandstone Member. The last two of Miocene) above it. these names are adopted herein; the first is re The Soda Lake Shale Member is also exposed in named (fig. 7). the southeastern Caliente Range, where the probable time-stratigraphic equivalent of the type section is QUAIL CANYON SANDSTONE MEMBER about 900 feet thick or less. It is of the same lith- The Soda Lake Shale Member in the southeastern ology as at the type section and in one place con Caliente Range is underlain in large part by a thin tains a lens of chert a few feet thick, just below the sandstone unit that was called the Soda Lake Sand middle. It is in part overlain by as much as 2,000 stone Member by Hill, Carlson, and Dibblee (1958, feet of siltstone and some interbedded sandstone p. 2984). Because the name Soda Lake is already that was included in the Soda Lake Shale Member applied to the overlying shale unit, this sandstone of this area by Vedder and Repenning (1965) be unit is here renamed the Quail Canyon Sandstone cause of its predominant siltstone lithology. Accord Member of the Vaqueros Formation. It is named for ing to them, this part contains foraminifers diagnos exposures in Quail Canyon, Cuyama quadrangle, tic of the Saucesian Stage and mollusks diagnostic 1964. The type locality is in the NWViSWi/i sec. of "Vaqueros age." Near the southeast end of this 4, T. 10 N., R. 25 W., which is the same as that range, all the strata assigned to the Soda Lake Shale 18 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA Member grade laterally eastward into the Painted of this member are somewhat higher stratigraphic- Rock Sandstone Member. ally than those near Caliente Peak and may be of According to R. L. Pierce (oral commun., 1970), "Temblor age," middle Miocene. the part of the Soda Lake Shale Member below the The Painted Rock Sandstone Member contains chert bed at the type section and the lowest part of undiagnostic shallow-water foraminifers, but foram- this member in the Cuyama Valley oil fields contain inifers diagnostic of the Saucesian Stage, early a neritic foraminiferal fauna diagnostic of the late Miocene, occur in the underlying beds of the Soda Zemorrian Stage and are probably correlative with Lake Shale Member and west of Caliente Mountain the Agua Sandstone Member and part of the under in the immediately overlying beds of the Monterey lying lower part of the Santos Shale Member of the Shale (Vedder and Repenning, 1965). Temblor Formation as defined herein; the part above On the northeast flank of La Panza Range, the the chert bed at the type section and the upper part Vaqueros Formation is nearly all sandstone and in the Cuyama Valley oil fields contain a subabyssal ranges from about 200 to 1,200 feet in thickness. fauna diagnostic of the early Saucesian Stage and It is assigned to the Painted Rock Sandstone Mem are probably correlative with the upper part of the ber because it is lithologically similar to that unit Santos Shale Member of the Temblor Formation as in the nearby northwestern Caliente Range and is defined herein. The faunas of the Soda Lake Shale conformably overlain by the Saltos Shale Member Member, according to Pierce, however, are unlike of the Monterey Shale. In most places the Painted those of the San Joaquin Valley, but are similar to Rock Sandstone Member rests unconformably on those of the same age in the Santa Ynez Mountains. crystalline basement rocks or on the Upper Creta Thus, the basin in which this member accumulated ceous and lower Tertiary sedimentary sequence, was probably not connected with the San Joaquin against which the lower beds buttress out. In other Valley basin at that time, as suggested by Cross places this member conformably overlies conglom (1962, p. 27). erate of the Simmler Formation, and at La Panza Canyon (in sec. 36, T. 29 S., R. 16 E.) it overlies PAINTED ROCK SANDSTONE MEMBER a thin intervening wedge as thick as 200 feet of The Painted Rock Sandstone Member was named the Soda Lake(?) Shale Member of the Vaqueros for Painted Rock, a prominent cavernous sandstone Formation. outcrop south of Soda Lake, but the type locality is The upper part of the Painted Rock Sandstone the section exposed in the vicinity of Caliente Moun Member of La Panza Range is generally fine grained tain, 7 miles northwest of New Cuyama (Hill and and fossiliferous, with abundant fossils of the Tur others, 1958, p. 2986, 2988). In the northwestern ritella ocoyana zone of "Temblor age," lower or Caliente Range this member is nearly all sandstone, middle Miocene. The lower part is medium to coarse but at Caliente Mountain and a few miles eastward grained, nearly white, and rarely fossiliferous, al it includes as much as 50 percent interbedded silt- though fossils of the Turritella inezana zone or stone. In these areas this member is about 5,500 "Vaqueros age," lower Miocene, were reported and feet thick. It thins to the southeast, in part by lat listed by Loel and Corey (1932, p. 107 and correla eral gradation of its lower beds into the Soda Lake tion chart). Shale Member and of its upper beds into the terres trial Caliente Formation and in part by actual TEMBLOR FORMATION thinning of the whole member. At the southeast end In the Temblor Range the Temblor Formation is of the Caliente Range, the Painted Rock Sandstone composed of sandstone and lesser amounts of argil Member is only about 600 feet thick. laceous sedimentary rocks. In the southeastern part The Painted Rock Sandstone Member in the of the range, as much as 7,000 feet crops out; the vicinity of Caliente Mountain and southeastward base of this unit is unexposed. In the northwestern contains abundant Turritella ocoyana and Lyropec- part this unit is much thinner but of variable thick ten miguelensis, especially in its upper and middle ness. At the northwest end of the Temblor Range parts. In other areas these species occur in sand and on the southwest flank of the Diablo Range near stones of "Temblor age." Eaton, Grant, and Alien Cholame Valley, the Temblor Formation is nearly (1941) assigned the upper 900 feet of this sand all sandstone and is 0-5,000 feet thick but generally stone unit to the "Temblor" and the rest to the less than 2,000 feet. At one place about 5 miles "Vaqueros." The fauna throughout this member is northeast of Cholame, the Temblor Formation con now considered to be of "Vaqueros age," early Mio tains a lens, as much as 500 feet thick, of terrestrial cene (Repenning and Vedder, 1961). In the north red beds, as mapped by Dickinson (1966a, p. 711, western Caliente Range, the uppermost sandstones pi. 1). At a locality 7 miles slightly south of east MIDDLE TERTIARY SEDIMENTARY SEQUENCE 19 R.18 E. R.19E. R. 20 E. R. 21 E. \\ North \ \ Antelope Hills T. 27 S '. Voil field '-., \ Antelope Hills -i-fr"' N. 'voil field McDonald Anti cline oil field T. 285. T. 29 S. EXPLANATION Point of Rocks Sandstone Pre-Tertiary rocks Temblor Formation FIGURE 9. Part of the Temblor Range showing geographic localities mentioned and areal extent of the Tertiary formations. of Cholame, the formation contains a basal con them from northeast to southwest with increasing glomerate lens as thick as 500 feet. The Temblor discordance toward the San Andreas fault. Formation is largely absent in the McLure Valley In most places the Temblor Formation is differ- area, but is present at Devils Den and Reef Ridge. entiable only into its facies of (1) sandstone, (2) Throughout the central and northwestern parts argillaceous sedimentary rocks, and (3) basal con of the Temblor Range and adjacent part of the glomerate (in one area only). These are unnamed; Diablo Range, the Temblor Formation rests either however, on the northeast flank of the central part disconforambly or unconformably on the lower Ter of the Temblor Range between Salt Creek and Bit- tiary, Cretaceous, and Franciscan rocks, overlapping terwater Creek (fig. 9) and in the nearby oil fields, 20 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA the Temblor Formation has for many years been as defined by Kleinpell (1938, p. 106-108). The divided informally by petroleum geologists into units members of the Temblor Formation in the Chico or members given local names. These units are of Martinez Creek area (fig. 10) are herein defined in little regional significance because they are thin, ascending order (thickness figures at Zemorra Creek very lenticular, and in outcrop recognizable only in as given by Woodring and others, 1940, p. 130). this part of the range. In the subsurface, however, The age of the Temblor Formation in its type they are economically very important because the area ranges from the early Zemorrian Stage, late sandstone units contain oil that is produced under Oligocene, through the Saucesian Stage, early Mio favorable structural conditions, and the shale units cene, to the lowest part of the Relizian Stage, mid form the caprocks. Mention is made of these units dle Miocene. This age range probably also applies in articles on descriptions of the nearby oil fields, to the Temblor Formation exposed in the south as well as in reports by Kleinpell (1938, p. 106, eastern Temblor Range and Devils Den. In areas fig. 6) and Goudkoff (1943), and the units are west and northwest of the type area and at Reef described, with pertinent references by Foss and Ridge, the Temblor Formation is mainly in the Blaisdell (1968, p. 33-43). These units, herein desig Saucesian Stage, early Miocene, and partly of Reli nated as members, are shown in table 2. zian age, middle Miocene. TABLE 2. Local stratigraphic units of the Temblor Forma CYMRIC SHALE MEMBER tion in the Temblor Range between Chico Martinet Creek The lowest shale member of the Temblor Forma and Bitterwater Creek (fig. 9) tion is commonly known as the Salt Creek Shale Thickness Stages (Williams, 1936; Goudkoff, 1943, pt. 2, p. 253, fig. Stratigraphic unit (ft) (Kleinpell, 1938) 99a; Curran, 1943, p. 1368-1369; Foss and Blais Buttonbed Sandstone Member 0-800 Relizian. Media Shale Member _____. 0-900 Lower Relizian and dell, 1968, p. 40), but this name is preoccupied. This upper Saucesian. Carneros Sandstone Member ______0-350 Saucesian. shale is herein renamed the Cymric Shale Member, Santos Shale Member 0-450 Lower Saucesian and Agua Sandstone Member and Zemorrian. for the nearby Cymric oil field (fig. 9). This mem as discontinous lenses as thick as 48 ft within Santos ber is disconformable on the Point of Rocks Sand Shale Member. Wygal ( =: "Phacoides") Sandstone Member. 0-100 Lower Zemorrian. stone and consists of dark-gray clayey to silty shale. Cymric (="Salt Creek") Shale Member_. 0-100 Zemorrian (?) It is traceable and recognizable in the outcrop only from Santos Creek southeastward to a point 3 miles Anderson (1905, p. 169-170) originally described southeast of Zemorra Creek (figs. 9, 11). The type the "Temblor Beds" at "Canara Springs" (Car section is in Zemorra Creek where this member is neros Spring in fig. 10) and at "Temblor." He never about 74 feet thick. Northeastward, downdip, it designated a type section, but Kleinpell (1938, p. thickens to several hundred feet in the subsurface. 107) and Curran (1943, p. 1364) considered the It contains sparse foraminifers of the Zemorrian section at Carneros Creek described by Anderson to Stage, late Oligocene, and forms the lower part of be the type locality of the Temblor Formation. Klein the type Zemorrian Stage (of Kleinpell, 1938, p. pell (1938, p. 107), Woodring, Stewart, and Rich 103-108). Recent faunal studies by W. O. Addicott ards (1940, p. 130), and Curran (1943, p. 1369- (oral commun., 1971) suggest, however, that the 1370) described the Temblor Formation exposed Cymric Shale Member may be at least in part in 2 miles south in Zemorra Creek, a branch of Chico the Refugian Stage, early Oligocene. If this is so, Martinez Creek (fig. 10), where the Temblor For this unit may be correlative with the Wagonwheel mation is thicker and more completely exposed than Formation near Devils Den. Nevertheless, to avoid at Carneros Creek. complications, its age assignment to the early Ze It is here proposed that the type area of the morrian Stage is tentatively retained. Temblor Formation be designated as the exposures from Carneros Creek to Zemorra Creek, the type WYGAL SANDSTONE MEMBER section as that exposed at Carneros Creek in sec. 32, The lowest sandstone member of the Temblor T. 28 S., R. 20 E., and a reference section as that Formation in the Chico Martinez Creek area is exposed at Zemorra Creek in sec. 9, T. 29 S., R. 20 commonly known as the "Phacoides reef" (Klein E. (figs. 9, 10). This type section is also the type pell, 1938, p. 107; Goudkoff, 1943, pt. 2, p. 250; section of some members of the Temblor Formation Curran, 1943, p. 1368) or "Phacoides Sand" (Foss and the reference section for the others, as indi and Blaisdell, 1968, p. 40). These names are not cated in the following paragraphs. Part of this sec valid because they refer to a fossil rather than a tion is also the type section of the Zemorrian Stage locality. Therefore this sandstone is here renamed MIDDLE TERTIARY SEDIMENTARY SEQUENCE 21 Cameros Creek /.Jmdo /Tmg ,! : 42> ;.' .'.' .* FORMATIONS AND MEMBERS LITHOLOGIC SYMBOLS i Pleisto-\Holo-[eerie cene Qa Alluvium Gravel 0 ° ° * QTt Tulare Formation Sandstone Te Etchegoin Formation Clay shale Belridge Diatomite Tmb Siliceous shale F^l Member ShaleMonterey irS Tm McLure Shale Cherty shale Member TTJl-i Tmd Devilwater Shale V++ Member Diatomite Tmg Gould Shale Member Buttonbed Sandstone 1MioceneOligocene Ttb Member or Ttm Media Shale Member TemblorFormation h- Carneros Sandstone o: Ttc Member UJh- 1 Santos Shale Tts Member Wygal Sandstone Ttw Member Tty Cymric Shale Member Point of Rocks Tpr §1 Sandstone FIGURE 10. Chico Martinez Creek area, Temblor Range, showing members of the Temblor Formation and Monterey Shale. the Wygal Sandstone Member, for Wygal Spring feet thick and overlies the Cymric Shale Member. (fig. 9). The type section is designated as that at This sandstone is gray, and its upper part is glau- Zemorra Creek, where this sandstone is about 75 conitic; locally a fossiliferous calcareous bed sev- 495-417 O - 73 - 4 22 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA CEDAR CREEK M/VPOLE ON [)E VILWA1 ER N IE DIA AC3UA C/\RNER OS Z EMO RR A MICRO- UJ EK FAUNAL AT MOUTH TWO MILES 3PRIN< C RE EK, 1 N 1ILE ClRE EK, 1L H^IILE CREEH CREE C5 E^EHE EAST OF MOUTH WEST c50 UTH EfkST STAGES 100' ^- m i es » 3 m iles *| 2n niles H ni les--ft 3 rr iles nniles- -» Mo nte re y shale (Gc uld ' 3h ale Mem ber -v- -/ ) Reliz- MIOCENE r 240' ::; 1 :: ian +- -t- - -/-- 150' (:: ::: 1::: 4°; L ?!!!!! - -/- B;;;;\ / 300' z 180' 500' 2-- 920' _ 2 _ Formationjmblor b 350' Formationlor CO 300' Sauce- CO § CM un 2200' L s 150' :: sian b o y o 120' § In CM 1000' - CO 350' Z" -160'-^ CM 100' 2 400' a J~ :..... 80' 400' 230' 100' t± D::3::: \\\-\-s\\\ _4&6_ 100' 180' -4&6- 50; 7v S ! b?;: ' c i6' .6 200' 3d' = 195' Zemor IOLIGOCENE?|EOCENE 85' rian 75' Poi nt of Rocks Sar idsto ne \ S^-N^ VE RTICA L SCA LE 123' [:: r500 FEET Nariz- LI THOL_OG,IC c;YM BOL-S ian 274' _4^_ pJ ______" '5 ' ' ' S ilicecus stiale Argil lacecIU ; shal«3 S andsto ne f -0 FIGURE 11. Sections of the Temblor Formation from Cedar Creek to Zemorra Creek in the Temblor Range (fig. 9). Units as follows: (1) Buttonbed Sandstone Member, (2) Media Shale Member, (3) Carneros Sandstone Member, (4) upper part of Santos Shale Member, (5) Agua Sandstone Member, (6) lower part of the Santos Shale Member, (7) Wygal Sandstone Member, and (8) Cymric Shale Member. Thicknesses shown other than for Zemorra Creek are approximate. eral feet thick occurs at or near the base. It is trace is conformable on the Wygal Sandstone Member. able south to Salt Creek and northwest to Media At Zemorra Creek, the reference section, this shale Agua Creek (figs. 9, 11). At both those places it member is 295 feet thick and is divided into two laps over the Cymric Shale Member onto the Point parts, but the lower part, 180 feet thick, is sepa of Rocks Sandstone. Northeastward, downdip from rated from the upper part, about 60 feet thick, by its outcrop, this member thickens to several hun the 35-foot-thick Agua Sandstone Member. The dred feet in the subsurface. It contains a molluscan upper part of the Santos Shale Member is traceable fauna assigned an early "Vaqueros age," late Oligo- northwestward to Cedar Creek, where it overlies the cene (W. 0. Addicott, oral commun., 1968), and the Agua Sandstone Member and the Point of Rocks shale immediately above and that below is in the Sandstone (fig. 11). Northeastward, downdip, the lower part of the type Zemorrian Stage (Kleinpell, Santos Shale Member thickens in the subsurface, 1938, p. 103-108). Recent work on the fauna from and the lower and upper parts are separated by the this sandstone unit by Addicott (oral commun., Agua Sandstone Member (Foss and Blaisdell, 1968, 1971) suggests, however, that this unit is somewhat p. 39-40). The Santos Shale Member contains fora- older than the "Vaqueros Stage," but younger than minifers diagnostic of the Zemorrian Stage, late the Refugian Stage. But to avoid complications, its Oligocene, in the lower part and of the Saucesian assignment to the "Vaqueros Stage" is tentatively Stage, early Miocene, in the upper part (Kleinpell, retained. 1938, p. 105-108; Foss and Blaisdell, 1968, p. 40). At Zemorra Creek the lower part forms the upper SANTOS SHALE AND AGUA SANDSTONE MEMBERS part of the type Zemorrian Stage of Kleinpell The middle shale member of the Temblor Forma (1938, p. 103-108), except the lowest 50 feet of that tion was named the Santos Shale by Gester and shale, which is assigned to the lower part of that Galloway (1933) for Santos Creek, the type locality stage (Foss and Blaisdell, 1968, p. 40). (fig. 9). This shale is medium to dark gray, clayey The Agua Sandstone Member was named Agua to silty, locally semisiliceous in the upper part, and Sandstone by Clark and Clark (1935, p. 137) for MIDDLE TERTIARY SEDIMENTARY SEQUENCE 23 Media Agua Creek (fig. 9). They did not designate light gray, clayey to silty, and in part semisiliceous. a type locality, although they mentioned the out It is conformable on the Carneros Sandstone Mem crop at the mouth of Cedar Creek. This outcrop is ber, is 920 feet thick at Zemorra Creek, the desig designated the type locality as it was mapped by nated type section (sec. 9, T. 29 S., R. 20 E., Car Heikkila and MacLeod (1951, pi. 1). This is the neros Rocks quadrangle), and about 500 feet thick only other place besides Zemorra, Creek, the refer at Carneros and Santos Creeks. It is traceable north ence section, where this unit crops out, although at west to and beyond the mouth of Cedar Creek (figs. a few places between Cedar Creek and Zemorra 9, 11). Northwest of Devilwater Creek it thickens Creek, the Santos Shale Member contains a sand as the upper parts of the Carneros Sandstone Mem stone bed a few feet thick that may be correlative. ber and lower parts of the Buttonbed Sandstone In the subsurface (in North Belridge, North and Member intertongue into it. In the Cedar Creek area South Antelope Hills, McDonald Anticline oil fields the Media Shale Member is as thick as 2,200 feet, and vicinity, (fig. 9) the Agua Sandstone Member and the upper part includes much hard semisiliceous is persistent, is several hundred feet thick, and is shale. assigned to the top of the Zemorrian Stage (Foss In the Chico Martinez Creek area, the Media and Blaisdell, 1968, p. 40). Shale Member contains foraminifers diagnostic of The Agua Sandstone Member is light gray, arko- the upper Saucesian Stage, early Miocene; the upper sic, and locally pebbly. At the mouth of Cedar Creek most 50 feet, a sandy siltstone, contains foraminifers it is as thick as 48 feet, occurs at the base of the diagnostic of the lower Relizian Stage, middle Mio Santos Shale Member, and is disconformable on the cene (Foss and Blaisdell, 1968, p. 39). Point of Rocks Sandstone (fig. 11). At this outcrop BUTTONBED SANDSTONE MEMBER it contains a few fossils, including Pecten magnolia, and is assigned a late "Vaqueros age" (W. 0. Addi- Anderson (1905, p. 170) referred to the top cott, oral commun., 1968). At Zemorra Creek this sandstone unit of his Temblor Beds at Carneros sandstone is 35 feet thick, is unfossiliferous, and is Creek as "button beds." This term has subsequently at the top of the type Zemorrian Stage (Kleinpell, been commonly applied informally to this sandstone 1938, p. 103-108), late Oligocene. (Kleinpell, 1938, p. 105; Foss and Blaisdell, 1968, p. 38). The type locality was designated as Carneros CARNEROS SANDSTONE MEMBER Creek (Heikkila and MacLeod, 1951, p. 10), in sec. The name Carneros was first applied to the mid 32, T. 28 S., R. 20 E. (fig. 10). It is here formally dle sandstone member of the Temblor Formation by named the Buttonbed Sandstone Member for its Cunningham and Barbat (1932, p. 417-421) for exposure on Buttonbed Hill (fig. 10). This sand Carneros Creek, the type locality (fig. 10). The Car stone is light gray, thick bedded, and commonly cal neros Sandstone Member is conformable on the careous, with numerous shell fragments. It ranges Santos Shale Member, is light gray and thick bedded, in thickness from 0 to 500 feet (240 ft thick at rarely contains fossils, and is about 215 feet thick Zemorra Creek, the reference section). It is pre at Zemorra Creek, the reference section, but as sumed to be locally disconformable on the Media much as 500 feet thick in the area of figure 9. It is Shale Member and may be a transgressive basal traceaible as far northwest as Cedar Creek (fig. 11). sandstone of the Monterey Shale, as indicated by Northwest of Devilwater Creek the upper part an unconformity locally at its base in the Shale intertongues into the lower part of the Media Shale Hills area (Heikkila and MacLeod, 1951, p. 10) and Member, and the lowest sandstone tongue persists at Devils Den. In other areas, this sandstone mem as a layer about 120 feet thick. Northeastward, ber or its equivalent is not differentiate from the downdip, the Carneros Sandstone Member thickens underlying sandstone fades of the Temblor Forma to more than 1,000 feet locally in the subsurface. tion. It is within the Saucesian Stage, early Miocene, as The Buttonbed Sandstone Member is traceable indicated by foraminifers from the shales below northwestward from Zemorra Creek to and beyond and above. Bitterwater Creek. Northwest of Devilwater Creek all but the upper part intertongues into the upper MEDIA SHALE MEMBER part of the Media Shale Member. The name Media was first applied to the upper The Buttonbed Sandstone Member contains mol- shale member of the Temblor Formation by Cun lusks and buttonlike echinoids (mostly Scutella ningham and Barbat (1932, p. 417-421), for Media merriami) assigned to "Temblor age," Miocene, Agua Creek (fig. 9). The Media Shale Member is (W. 0. Addicott, oral commun., 1967). In the Chico 24 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA Martinez Creek area, the Buttonbed Sandstone Mem The terms Monterey Series and Maricopa Shale ber is in the early Relizian Stage (middle Miocene), were discarded after 1935, and the term Monterey as indicated by the microfauna in the adjacent shale Shale was adopted for the lithologic unit of "pre below and above (R. L. Pierce, oral commun., 1968). dominantly hard silica-cemented shales and softer At Devils Den, local names were applied to units shales carrying siliceous microfossils" (Wilmarth, within the Temblor Formation by Van Couvering 1938, p. 1407, 1299). The term Monterey Shale was and Alien (1943, p. 496-500) ; none of these are applied to this unit by Woodring, Bramlette, and adopted herein. The members recognized in the Kleinpell (1936, p. 127-146), Kleinpell (1938, p. 7, Chico Martinez Creek area of the Temblor Range 105; 122, fig. 6), Woodring, Stewart, and Richards are believed to be as indicated in table 3, mainly on (1940, p. 122-123), Hill, Carlson, and Dibblee (1958, p. 2988-2991), and Durham (1963, 1964, 1966). The TABLE 3. Members of the Temblor Formation exposed at term Monterey Formation was also applied (Simon- Devils Den son and Krueger, 1942, p. 1616; Bramlette and Name applied by Daviess, 1944; Heikkila and MacLeod, 1951, p. 5, 11, Van Couvering and Alien (1943.) pi. 1; Foss and Blaisdell, 1968, p. 36), but because Average (Members 1-5 Name of member thickness assigned to Hannah this unit is characterized by a distinctive shale, the (ft) Formation) term Monterey Shale is hereby retained. Buttonbed Sandstone Member ______50 Escudo Formation. Media Shale Member __- ______350 Member 1. The Monterey Shale is the most extensive unit Carneros Sandstone Member 200 Member 2 (sand (includes interbedded shale). stone and shale). of the middle Tertiary sedimentary sequence on Upper part of Santos Shale Member _ _ 300 Member 3 (shale). Undivided lower members: Member 4 (sand both sides of the San Andreas fault, in places ex Agua Sandstone Member _ 180 stone). Lower part of Santos Shale Member _ 100 Member 5 (shale). tending beyond the limits of the Vaqueros and Wygal Sandstone Member 70 Do. Cymric Shale Member 50 Do. Temblor Formations. It was deposited under con ditions of maximum inundation during the middle the basis of similar lithologic sequences, although Tertiary sedimentary cycle. correlations are uncertain. In the northern expo STRATIGRAPHIC UNITS SOUTHWEST OF THE sures, the Buttonbed Sandstone Member overlaps SAN ANDREAS FAULT the older members of the Temblor Formation. Southwest of the San Andreas fault, the Mon MONTEREY SHALE terey Shale is from 2,000 to 3,000 feet thick on the REVIEW OF NOMENCLATURE southwest flank of the Caliente Range and the A distinctive marine deposit of predominantly northeast flank of the La Panza Range, from which siliceous organic shale, of early, middle, and late it extends northwestward under Salinas Valley. In Miocene age, overlies the Vaqueros and Temblor the Caliente Range, Cuyama Valley, and Sierra Formations. In the Temblor Range and part of the Madre Mountains, the Monterey Shale intertongues Caliente Range, the name Monterey Shale was ap northeastward into sandstone mapped as the Branch plied to this unit by Arnold and Johnson (1910, Canyon Sandstone (figs. 7, 12). In the La Panza p. 55-62, pi. 1), who adopted the name from the Range and western Cuyama Valley, the Monterey term Monterey Formation applied by Blake (1856, Shale thins to only a few hundred feet; in places p. 328-331) to a similar siliceous deposit exposed it wedges out. near Monterey. The Monterey Shale exposed in the areas between Confusion resulted when part of this siliceous the San Andreas and Rinconada faults is composed shale unit in the Diablo Range, Temblor Range, and of two lithologic units: a lower unit of predomi Caliente Range was correlated with and assigned nantly argillaceous shale of middle and locally in to the Santa Margarita Formation by Arnold and part of early Miocene age and an upper unit of Anderson (1910) and English (1916, p. 202-203), siliceous shale of middle Miocene age. The lower and the name Maricopa Shale was applied to the unit has been named the Saltos Shale Member, and rest of this shale unit in the Caliente Range by the upper unit the Whiterock Bluff Shale Member English (1916, p. 198-200, pi. XIX) and in the (fig. 7). Temblor Range by Pack (1920, p. 35-41, pi. II). In several wells in the valley area between Atas- This was done when the terms Monterey Series (of cadero and Shandon, the uppermost part (as much Louderback, 1913, p. 191-214) and Monterey Group as 300 feet) of the Monterey Shale contains fora- (of Lawson, 1914) were applied to most of the minifers diagnostic of the late Miocene Mohnian Miocene marine sedimentary rocks of the California Stage (H. C. Wagner, oral commun., 1970). Part Coast Ranges. of the Monterey Shale exposed north of Atascadero MIDDLE TERTIARY SEDIMENTARY SEQUENCE 25 EXPLANATION Contact Dotted where concealed Fault Dotted where concealed or inferred Buried Buried Buried Predominantly Monterey Predominantly Branch Canyon Predominantly Caliente Shale northeast of San Sandstone Formation Andreas fault, Santa Margarita Sandstone and Monterey Shale south west of San Andreas fault FIGURE 12. Probable original and present areal extent of contemporaneous formations or facies of mainly middle and late Miocene age in southern Coast Ranges. may also be of Late Miocene age. These are the extensive in Salinas Valley, to the northwest. only places within the area of figure 2 southwest of SALTOS SHALE MEMBER the San Andreas fault where the Monterey Shale is The Saltos Shale Member was named for Saltos of late Miocene age. Monterey Shale of that age is Creek near the type locality (sees. 18, 19, and 20, 26 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA T. 11 N., R. 27 W., San Bernardino base line and contains foraminifers of the Luisian Stage and that meridian) in the central Caliente Range, 8-9 miles grades laterally westward into the Whiterock Bluff northwest of New Cuyama, by Hill, Carlson, and Shale Member (fig. 7). The siltstone of the Saltos Dibblee (1958, p. 2989-2990), and the name is Shale Member intertongues northeastward into herein adopted. According to them, the member is the Branch Canyon Sandstone within a few miles about 2,150 feet thick at the type locality: the lower of the San Andreas fault (fig. 12). part, about 1,000 feet thick, is composed of gray clay shale and siltstone and is separated by a sill of WHITEROCK BLUFF SHALE MEMBER basalt about 75 feet thick from the upper part, In the Caliente Range, La Panza Range, and about 1,100 feet of soft fissile shale and hard, brittle Sierra Madre Mountains, the siliceous shale unit siliceous shale and frequent thin beds of dolomite. was named the Whiterock Bluff Shale Member of The lower part was assigned to the Saucesian Stage, the Santa Margarita Formation by English (1916, early Miocene, and the upper part to the Relizian p. 191-215, pi. XIX). This shale unit was named Stage, middle Miocene. for Whiterock Bluff, the type locality (sec. 25, T. The Saltos Shale Member exposed northwestward 11 N., R. 28 W.), about 8 miles west-northwest of along the Caliente Range and in the La Panza New Cuyama (fig. 1), where this shale is approxi Range is generally similar to that at the type local mately 1,200 feet thick. This name was adopted and ity, but in these places it lacks the basalt and aver applied to this shale unit by Hill, Carlson, and Dib ages about 1,500 feet in thickness. In the La Panza blee (1958, p. 2990-2991), but the unit was reas and northwestern Caliente Ranges, the Saltos Shale signed to the Monterey Shale. The Whiterock Bluff Member is composed of soft-weathering yellowish- Shale Member was reported by them to contain gray thin-bedded clayey to weakly siliceous or cal foraminifers diagnostic of late Relizian and Luisian careous shale and contains a foraminiferal fauna Stages, middle Miocene. This name as used by Hill, of the Relizian Stage, middle Miocene. It conform Carlson, and Dibblee (1958) is adopted herein for ably overlies the Painted Rock Sandstone Member this shale unit in the area between the San Andreas of the Vaqueros Formation, in places with a grada- and Rinconada faults. tional or intertonguing contact. In both these areas The Whiterock Bluff Shale Member consists of this shale unit is lithologically similar to and correl hard, brittle thin-bedded siliceous shale and inter- ative with the Sandholdt Formation of Thorup bedded fissile to punky shale. It is as much as 1,500 (1943) in Salinas Valley. feet thick, but averages 1,200 feet. It is gradational Near the west end of Cuyama Valley, the lower downward into the Saltos Shale Member and up 150 feet of the Saltos Shale (?) Member is semi- ward into sandstone of the Santa Margarita Forma siliceous shale, and the upper 500 feet is clay shale tion. For about 6 miles on each side of Indian Creek that is overlain by the Branch Canyon (?) Sand (about 12 miles south of Shandon, fig. 2), a zone stone. The shale there contains foraminifers as about 70 feet thick near the top of the Whiterock signed to the lower(?) Saucesian Stage (R. L. Bluff Shale Member contains thin layers of phos- Pierce, oral commun., 1967). Where the Vaqueros phatic pellets and bentonite (H. D. Gower, oral Sandstone is missing, the shale overlies the Simmler commun., 1970). This zone is overlain by about 80 Formation and underlying rocks of Paleocene(?) feet of siliceous and diatomaceous shale, which is age with angular discordance of as much as 45°. overlain by the Santa Margarita Formation. In This is the only place between the San Andreas and western Cuyama Valley and on the southwest flank Rinconada faults where an angular unconformity of the La Panza Range, the Whiterock Bluff Shale appears within the middle Tertiary sedimentary Member is absent or may be represented by sand sequence. stone. Elsewhere this shale unit is widely distri On the northeast flank of the Caliente Range, on buted, and in Salinas Valley this member and the both flanks southeast of Caliente Mountain, and in underlying Saltos Shale Member are recognizable the eastern San Rafael Mountains, the Saltos Shale in well logs as far northeast as San Juan Creek. It Member becomes mainly siltstone, in places contain is noteworthy, however, that within 7-10 miles of ing sparse foraminifers of the Saucesian and Reli the San Andreas fault, as in the Caliente Range, zian Stages, and thin sandstone beds that contain this siliceous shale unit grades laterally northeast mollusks of the "Temblor Stage" (Vedder and ward through siltstone of the Saltos Shale Member Repenning, 1965). Included in the Saltos Shale Mem lithology into the Branch Canyon Sandstone (figs. ber of these exposures is several hundred feet of 7,12). similar but stratigraphically higher siltstone that In many places the Whiterock Bluff Shale Mem- MIDDLE TERTIARY SEDIMENTARY SEQUENCE 27 her contains abundant calcareous foraminifers. hills of the Diablo Range, and in Devils Den area, These are diagnostic of the Luisian Stage, middle the lower division of the Monterey Shale is about Miocene. The exposure of the Whiterock Bluff Shale 1,000 feet thick and is locally absent; it is com Member in sec. 21, T. 28 S., R. 14 E., 12 miles east posed only of argillaceous shale. In the McLure of Atascadero (fig. 2) is the type locality of the Valley-Reef Ridge area, the lower division is largely Luisian Stage, as defined by Kleinpell (1938, p. 121- absent. 123). In the Indian Creek area, the phosphatic pellet Because at their type localities at Chico Mar zone near the top of the member and 30 feet of the tinez Creek in the central Temblor Range the Gould overlying shale also contain foraminifers of the Shale Member is a siliceous shale unit and the Luisian Stage (H. D. Gower, oral commun., 1970). Devilwater Shale Member is an argillaceous shale At the type locality of the Whiterock Bluff Shale unit, the name Gould Shale Member is here adopted Member in Cuyama Valley, this member is mainly and applied throughout the Temblor Range to the in the Luisian Stage, but the lowest part is in the part of the lower division of the Monterey Shale upper Relizian Stage (Hill and others, 1958, p. that is mainly siliceous shale and is within the Reli 2991), middle Miocene. zian and Luisian Stages, middle Miocene (and in one STRATIGRAPHIC UNITS NORTHEAST OF THE place late Saucesian Stage); the name Devilwater SAN ANDREAS FAULT Shale Member is adopted and applied to the part Northeast of the San Andreas fault, the Mon- that is mainly argillaceous shale and is within the terey Shale conformably overlies the Temblor For Luisian Stage, middle Miocene age, in the Temblor mation and is about 7,200 feet thick in the south Range and southeastern Diablo Range. These names eastern and central parts of the Temblor Range. are thereby applied to lithologic rather than paleon- Northwestward, it thins to about 2,600 feet in the tologic units. Diablo Range north of Cholame and to only 600 feet Southwest of the Recruit Pass fault in the south on Reef Ridge and northwest of McLure Valley. eastern Temblor Range, the lower division of the The Monterey Shale may be divided regionally into Monterey Shale is composed of semisiliceous shale, two parts: a lower division mainly of middle Mio similar to that of the Gould Shale Member, and cene age and an upper division mainly of late Mio about 50 percent of intenbedded sandstone. cene age. The upper division of the Monterey Shale is a The only place northeast of the San Andreas unit of thin-bedded siliceous shale and (or) siliceous fault where a complete section of the Monterey mudstone throughout the region northeast of the Shale is continuously exposed in a homoclinal struc San Andreas fault. In the southeastern and central ture is along Chico Martinez Creek in the Temblor parts of the Temblor Range, it is 4,000-5,000 feet Range (fig. 10). This section is the upward con thick. Northwestward it thins to about 1,900 feet tinuation of the Zemorra Creek section of the under in the Diablo Range north of Cholame and to only lying Temblor Formation. Therefore this section is 550 feet in the McLure Valley-Reef Ridge area. designated as the reference section for the Mon Unfortunately this shale unit has a complex and terey Shale and its members, as well as for the confused terminology because its identity as a Temblor Formation, northeast of the San Andreas single lithologic unit throughout this region has not fault. This section of the Monterey Shale was de been recognized. scribed by Woodring, Stewart, and Richards (1940, In the Diablo Range and parts of the Temblor p. 125), who measured and divided it into 11 num Range, the upper division of the Monterey Shale bered units. was originally referred to the Monterey Shale by In the southeastern and central parts of the Tem Anderson (1905, p. 171, pi. 34), but a few years blor Range, the lower division of the Monterey later it was assigned to the Santa Margarita For Shale is 2,000-3,000 feet thick and is composed mation by Arnold and Anderson (1908, p. 35-39, mostly of siliceous shale that is not lithologically pi. 1), Arnold and Johnson (1910, p. 63-72), and differentiable. On the northeast flank of the central English (1918, p. 229-230, pi. 2) when that name part of the Temblor Range, this division is about was applied to all strata of late Miocene age in the 1,300 feet thick: the lower part is siliceous shale Coast Ranges, regardless of their lithology. Still that is locally known as the Gould Shale Member, later, this siliceous shale unit in the Diablo Range and the upper part is argillaceous shale that is was named McLure Shale by Henny (1930, p. 403- locally known as the Devilwater Shale Member. In 410) because he thought that the sandstone that the northwestern Temblor Range, southwest foot locally unconformably underlies it 14 miles west of 28 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA Coalinga (NW^4 sec. 17, T. 21 S., R. 13 E.) was the | Therefore it is appropriate to eliminate all but one Santa Margarita Sandstone on the basis of fossils. name. Santa Margarita has been eliminated for this That sandstone is now known to be the Temblor. unit because this name is no longer applied to a Since then, the name McLure has been so much shale unit. The names McDonald and Antelope, used for this shale unit that it was adopted by widely used in the subsurface but mainly as paleon- Woodring, Stewart, and Richards (1940, p. 114, tologic units, are preoccupied and therefore not 122-125) and Stewart (1946, p. 103-104, pi. 9), adopted. The usage of the term McLure Shale Mem and they designated this unit as a member of the ber of the Monterey Shale by Woodring, Stewart, Monterey Shale. In the southern part of the Diablo and Richards (1940, p. 114, 122-125) and Stewart Range, this shale unit was referred to the McLure (1946, p. 303-304) is adopted herein for the sili Shale by Marsh (1960, p. 32-33, pi. 1) and to the ceous shale unit of mainly late Miocene age of the Monterey Formation by Dickinson (1966a, p. 713, Monterey Shale throughout the entire region north fig. 4, pi. 2; 1966b, pi. 1). east of the San Andreas fault. In the Chico Martinez Creek area of the Temblor The lithologically distinct members or units of Range, the upper division of the Monterey Shale the Monterey Shale northeast of the San Andreas was for many years informally divided by petroleum fault recognized on the basis of lithology are shown geologists into two local stratigraphic units or mem in figure 10 and discussed in the following sections. bers. The lower unit was called McDonald Shale GOULD SHALE MEMBER (Cushman and Goudkoff, 1938, pi. 1) or McDonald The siliceous shale that forms the lowest unit of Shale Member of Monterey Formation (Simonson the Monterey Shale exposed at Chico Martinez Creek and Krueger, 1942, p. 1616-1617; Foss and Blais- was named the Gould Shale Member of the Temblor dell, 1968, p. 37), presumably for the McDonald Formation by Cunningham and Barfoat (1932, p. anticline oil field. This unit presumably corresponds 418) for nearby Gould Hill (fig. 10). They desig to Monterey Shale units 4 and 5 (total thickness nated the type locality as the area between the ex 1,105 ft) of Woodring, Stewart, and Richards (1940, posure along that creek and 2 miles southeastward p. 125) and contains foraminifers diagnostic of the (fig. 10). This name was adopted as a member of early Mohnian Stage. The upper unit was called the Monterey Shale by Woodring, Bramlette, and Antelope Shale (Noble, 1940, p. 1332, fig. 1) or Kleinpell (1936, p. 127-146), Woodring, Stewart, Antelope Shale Member of Monterey Shale (Simon- and Richards (1940, p. 125), Heikkila and MacLeod son and Krueger, 1942, p. 1611, 1617, fig. 2; Foss (1951, p. 11-12), and Foss and Blaisdell (1968, and Blaisdell, 1968, p. 37), presumably for Antelope p. 38). Valley. This unit probably corresponds to Monterey The Gould Shale Member is composed of tan- Shale units 6-9 (total thickness 3,815 ft) of Wood- weathering thin-bedded brittle siliceous shale alter ring, Stewart, and Richards (1940, p. 125) and nating with softer fissile shale. It conformably over contains diatom remains and sparse foraminifers lies the Buttonbed Sandstone Member of the Tem assigned to the late Mohnian Stage. The McDonald blor Formation and is overlain by the Devilwater and Antelope units are composed of siliceous shale Shale Member of the Monterey Shale. At the type and are thus difficult to distinguish. In the adjacent locality, the Gould Shale Member is 285 feet thick subsurface area they are recognized on the basis of (Woodring and others, 1940, p. 125), but to the paleontology and electric log correlations. northwest it is as thick as 600 feet. From the type In the Shale Hills area of the northwestern Tem locality, it is traceable northwestward for about blor Range (about 8 miles south of Devils Den), the 20 miles and then disappears, never to reappear. upper division of the Monterey Shale was referred In all these exposures, the Gould Shale Member to the McDonald Shale Member by Heikkila and contains foraminifers diagnostic of the Relizian MacLeod (1951, p. 13-14, pi. 1). In the central and Stage, middle Miocene (Kleinpell, 1938, fig. 14; southeastern parts of the Temblor Range, this di Foss and Blaisdell, 1968, p. 38). vision was mapped informally as the Antelope- In the southeastern part of the Temblor Range McDonald Shale Member by Simonson and Krueger and southwest flank of the central part, all the (1942, p. 1611, 1617) and Dibblee (1962, 1968). lower division, or middle Miocene part, of the Mon The application of four names to the siliceous terey Shale is composed of siliceous shale lithologic shale of the upper division of the Monterey Shale ally similar to the Gould Shale Member of the Chico or parts of it is the source of much confusion. It Martinez Creek area. All this siliceous shale is was found impractical to differentiate this shale unit therefore assigned to the Gould Shale Member on in the field, especially where it is complexly folded. the basis of lithologic similarity, even though the MIDDLE TERTIARY SEDIMENTARY SEQUENCE 29 upper part is presumably correlative in age with In the Temblor Range the Devilwater Shale Mem the Devilwater Shale Member of the Chico Marti- ber contains foraminifers diagnostic of the middle nez Creek area (fig. 10). In the southeastern Tem Miocene Luisian Stage (Foss and Blaisdell, 1968, blor Range, this siliceous shale unit was informally p. 38). It is presumably of the same age in the called Devilwater-Gould member of the Monterey Diablo Range. In the subsurface of the Kettleman (Simonson and Krueger, 1942, p. 1611, 1616, 1626- Hills, it and the correlative of the Gould Shale Mem 1627; Dibblee, 1962, 1968). This unit, now desig ber are represented mostly by sandstone which nated as the Gould Shale Member, is from 2,000 to there was assigned to the Temblor Formation by 3,000 feet thick; it conformably overlies clay shale Woodring, Stewart, and Richards (1940, fig. 8). of the Temblor Formation and is overlain by the INTERBEDDED SHALE AND SANDSTONE MEMBER McLure Shale Member of the Monterey Shale. In On the southwest slope of the southeastern part these exposures, the Gould Shale Member contains of the Temblor Range and southwest of the Recruit foraminifers diagnostic of the Relizian Stage in the Pass fault, the conglomerate of the Santa Marga- lower part and Luisian Stage, middle Miocene, in rita Formation is unconformably underlain by Mon the upper part. In one place in the extreme south terey Shale of which as much as 1,500 feet is ex eastern Temblor Range, however, the lowest strata posed although the base is buried. The shale is of this siliceous shale unit contain foraminifers semisiliceous and contains about 50 percent inter- diagnostic of the late Saucesian Stage, early Mio bedded light-gray sandstone. The shale contains cene (R. L. Pierce, oral commun., 1967). foraminifers diagnostic of the Relizian and Luisian DEVILWATER SHALE MEMBER Stages, middle Miocene (Vedder, 1970), and is The argillaceous shale that forms the upper part therefore correlative with the Gould Shale Member of the lower division of the Monterey Shale in the east of the Recruit Pass fault. northwestern Temblor Range is locally known as M'LURE SHALE MEMBER the "Devilwater Silt" (Bailey, 1939, p. 317; Heikkila The McLure Shale Member is composed of white- and MacLeod, 1951, p. 11-12, pi. 1; Foss and Blais- weathering dark-brown thin-bedded chalky to hard dell, 1968, p. 38). It is presumably named for Devil- porcelaneous siliceous shale. The type locality, desig water Creek (fig. 9). This name is adopted herein nated by Henny (1930, p. 404, table 1), is in sec. because of its long established usage but is modi 8 (not sec. 6), T. 24 S., R. 17 E., on the west side fied to Devilwater Shale Member because it is not of McLure Valley, for which it was named. At that "silt" (an unconsolidated sediment) but is clayey locality, this shale is 800 feet thick and is uncon- shale with lesser amounts of siltstone and fine formable on the Panoche Formation. In the McLure grained sandstone. The type section is here desig Valley and Reef Ridge areas, this member ranges nated as the section exposed at Chico Martinez from 550 to 1,000 feet in thickness, thinning north Creek, where it is composed of 1,190 feet of soft ward, and is unconformable on the Temblor and clayey shale, locally containing abundant foramini older formations. In the Reef Ridge area the McLure fers, and silty mudstone (Monterey Shale units 3 Shale Member locally contains a basal conglomerate and 4 of Woodring and others, 1940, p. 125) sepa and sandstone with serpentine clasts (Stewart, 1946, rating the Gould Shale Member below from the p. 98, 103-104; Adegoke, 1969, p. 20). On the McLure Shale Member above (fig. 10). southwest flank of the Diablo Range and in the The Devilwater Shale Member is about 1,000 northwestern part of the Temblor Range, the Mc feet thick in most exposures. It persists northwest Lure Shale Member thickens southeastward to about of Packwood Creek into the southwest foothills of 5,000 feet and is conformable on the Devilwater the Diablo Range east of Cholame Valley, where it Shale Member or unconformable on the Point of was mapped as the upper Temblor Sandstone by Rocks Sandstone or Panoche Formation where the Marsh (1960, pi. 1) and as the oiltstone member of Devilwater Shale Member and Temblor Formation the Vaqueros-Temblor Formation by Dickinson are absent. In these areas the McLure Shale Mem (1966a, p. 711-713, pi. 2). The Devilwater Shale ber contains one or more lenses of sandstone (Po- Member is also present in the Devils Den area, lonio Sandstone Tongue in McLure Shale of Marsh, where it is about 700 feet thick. There it was called 1960, p. 32-33). Alferitz Formation and assigned to the Luisian The reference section of the McLure Shale Mem Stage, middle Miocene, by Van Couvering and Alien ber of the Monterey Shale is here designated at (1943, p. 496-500), but the name Alferitz is not Chico Martinez Creek in sees. 10 and 11, T. 29 S., adopted. R. 20 E. (fig. 10), where it is completely exposed. 30 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA There it conformably overlies the Devilwater Shale miles north of the type section, and near Gould Hill, Member and grades upward into the Belridge Diato- 2 miles southeast, this diatomite unit is overlain mite Member. In this section the McLure Shale disconformably by the Etchegoin Formation. Member is 4,930 feet thick and corresponds to Mon- In the foothills of the Temblor Range from Mc- terey Shale units 4-9 of Woodring, Stewart, and Kittrick to Maricopa, the Belridge Diatomite Mem Richards (1940, p. 125). This siliceous shale mem ber is discontinuously exposed and is similar to the ber includes units informally called McDonald Shale, Belridge at Chico Martinez Creek. Just west of Taft, Antelope Shale, and Chico Martinez Chert Members as much as 2,200 feet of this unit is exposed uncon- (San Joaquin Geological Society, 1959, p. 13; Foss formably below the Tulare Formation. and Blaisdell, 1968, p. 37; Elliot and others (1968, The Belridge Diatomite Member has been corre p. 110-112). These terms are not adopted because lated with the Reef Ridge Shale and assigned a all these units are composed of siliceous shale, and Miocene and Pliocene age by Foss and Blaisdell outside the Chico Martinez Creek area it is not pos (1968, p. 36-37). It is, however, lithologically un sible to differentiate them on a lithologic basis with like the Reef Ridge Shale near Reef Ridge. In the certainty on the surface. The lowest unit, the Mc exposed sections, the Belridge Diatomite Member Donald of local usage, is recognizable in the Elk contains foraminifers and fish scales diagnostic only Hills and other oil fields on the basis of electric log of the late Mohnian Stage, late Miocene (R. L. patterns and early Mohnian foraminifers (J. C. Pierce, oral commun., 1967). Maher, oral commun., 1970). From field relations the Belridge Diatomite Mem In the southeastern part of the Temblor Range, ber is considered to be older than the type Reef the McLure Shale Member is from 3,000 to 5,000 Ridge Shale because in the extreme southeastern feet thick and grades upward into the Belridge Temblor Range the Santa Margarita Formation, Diatomite Member. It overlies similar siliceous which intertongues into the Belridge Diatomite shale of the Gould Shale Member from which it is Member, is overlain by the Bitterwater Creek Shale, differentiated mainly by a color change; the McLure which in turn is probably correlative with the type Shale Member weathers white, whereas the Gould Reef Ridge Shale. If this is so, then the Belridge Shale Member weathers cream to buff and is some Diatomite Member may be correlative with the what less siliceous and more fissile. Near Taft and upper part of the McLure Shale Member of the Maricopa, the McLure Shale Member contains sev McLure Valley-Reef Ridge area. eral lenses of sandstone. The relationship of the Belridge Diatomite Mem The McLure Shale Member contains much diatom ber exposed in the Temblor Range to the unexposed debris, arenaceous foraminifers, and fish scales. It Reef Ridge Shale in the oil fields to the east is un also contains sparse calcareous foraminifers diag certain because the exposed Belridge Diatomite nostic of the Mohnian Stage, late Miocene (R. L. Member has not definitely been recognized in the Pierce, oral commun., 1968). Only in the extreme oil field subsurface area. These units have been cor southeastern part of the Temblor Range do the related on the basis pf supposed similar stratigraphic lowest beds contain foraminifers of the middle Mio position (Foss and Blaisdell, 1968, p. 36), even cene Luisian Stage (Vedder, 1970). though they are different lithologically. Subsurface structural data suggest that the Belridge Diatomite BELRIDGE DIATOMITE MEMBER Member correlates wtih the upper part (the Ante The Belridge Diatomite Member, designated here lope Shale of drillers) of the McLure Shale Mem in as the uppermost member of the Monterey Shale, ber in the subsurface and dips under the subsurface was named informally by Siegfus (1939, p. 29) and argillaceous(?) unit referred to the Reef Ridge Young (1943, p. 523-524) for the South Belridge Shale (H. C. Wagner, oral commun., 1970). If this oil field (fig. 9). The type section is herein desig is correct, the exposed Belridge Diatomite Member nated as the section exposed near the mouth of is older than the Reef Ridge Shale of the subsurface. Chico Martinez Creek (SEi/4 sec. 2, T 29 S., R 20 Because of the foregoing evidence, the Belridge E., fig. 10). This member corresponds to Monterey Diatomite Member exposed in the Temblor Range Shale units 10 and 11 (total exposed thickness 830 is assigned to the late Mohnian Stage, late Miocene, ft) of Woodring, Stewart, and Richards (1940, p. and is considered to be older than the Reef Ridge 125). It is composed of white-weathering soft fissile Shale. to punky diatomite that grades downward into the BRANCH CANYON SANDSTONE McLure Shale Member and is overlain unconform- Marine sandstone that grades laterally westward ably by the Tulare Formation. At Bacon Hills, 2 into the Monterey Shale in the Sierra Madre Moun- MIDDLE TERTIARY SEDIMENTARY SEQUENCE 31 tains and Caliente Range (fig. 7) was named the Margarita Formation by Fairbanks (1904) for ex Branch Canyon Formation by Hill, Carlson, and posures at Santa Margarita, the type locality (8 Dibblee (1958, p. 2991-2993) for Branch Canyon miles southeast of Atascadero, fig. 2). This usage (3 miles south of New Cuyama), the type section is herein retained for this sandstone unit. (sec. 2. T. 9 N., R. 27 W.). This usage is adopted The Santa Margarita Formation is about 1,500 herein but the name is modified to Branch Canyon feet thick in most places and is composed mainly of Sandstone. white friable sandstone. In some places, such as In the Branch Canyon area south of Cuyama north of the La Panza Range and also south of Valley, the Branch Canyon Sandstone is about Cuyama Valley, it contains thin rhyolitic tuffaceous 3,200 feet thick. The lower 2,100 feet ("Vaqueros," beds, zones of phosphatic pellets, and one or two "Temblor," and "Briones," of Eaton and others, thin units of silty diatomaceous siliceous shale. 1941, fig. 13) contains mollusks and echinoids diag South of Cuyama Valley the Santa Margarita For nostic of the "Temblor Stage," middle Miocene. The mation is underlain by upper Miocene beds of the upper 1,100 feet ("upper Briones," "Cierbo," and Branch Canyon Sandstone, from which it is arbi "lower Neroly" of Eaton and others, 1941, fig. 13) trarily separated by a shale unit at the base of the contains mollusks and echinoids diagnostic of the Santa Margarita Formation. In one exposure just "Santa Margarita Stage," late Miocene, and is over west of Carrizo Plain, the Santa Margarita Forma lain by the Santa Margarita Formation. Farther tion tongues eastward into nonmarine red beds. east, the Branch Canyon Sandstone is overlapped Within a few miles of the San Andreas fault in the by and tongues out into nonmarine formations. southeastern Caliente Range and under Carrizo In the Caliente Range, the Branch Canyon Sand Plain, the Santa, Margarita Formation is not pres stone is as much as 3,000 feet thick. There it con ent, but is probably represented by the upper part tains mollusks of the "Temblor Stage," middle Mio of the Caliente Formation. cene, only. It intertongues southwestward into the The sandstone of the Santa Margarita Formation Saltos Shale Member of the Monterey Shale in both contains shallow-water marine mollusks and echi northwestern and southeastern parts of the range. noids of the "Santa Margarita Stage," late Miocene. In the southeastern part, it is overlain by and It was deposited as a littoral marine facies of a tongues laterally eastward into the Caliente Forma regressing sea. tion. Northeast of the San Andreas fault, coarse clastic Several wells drilled for petroleum in the western deposits in the upper Miocene section are present parts of the Carrizo Plain and near the San Juan only in the southeastern part of the Temblor Range. River to the northwest and a well northwest of In this area very coarse conglomerate, which locally Cholame penetrated sandstone of, or correlative contains mollusks of late Miocene age, was referred with, the Branch Canyon Sandstone. These occur to the Santa Margarita Formation by Simonson and rences and the exposures of this sandstone along Krueger (1942 p. 1619-1621). This usage is re the northeastern flank of the Caliente Range sug tained herein. This conglomerate, which also in gest that the Branch Canyon Sandstone may be con cludes lenses of breccia and sandstone, is as much as tinuous under the southwestern part of the Carrizo 2,500 feet thick. It intertongues northeastward, Plain to and beyond Cholame. Along this strip, this downdip, into the Belridge Diatomite Member of marine sandstone intertongues southwestward into the Monterey Shale. the Monterey Shale and northeastward toward the San Andreas fault into the Caliente Formation (fig. CALIENTE FORMATION 12). Similar conditions prevail in the eastern Sierra In areas southwest of the San Andreas fault, Madre Mountains and presumably under Cuyama terrestrial deposits that intertongue westward into Valley. These relations indicate that the Branch the marine deposits of Miocene age (fig. 7) were Canyon Sandstone is essentially a strandline deposit named the Caliente Formation by Hill, Carlson, and between the Monterey Shale deposited offshore to Dibblee, 1958 p. 2993-2995) for the Caliente Range. the southwest and the terrestrial Caliente Forma The type locality was designated in the southeastern tion to the northeast. part of the range in sees. 26 and 23, T. 11 N., R. 26 W., 5-6 miles northeast of New Cuyama. This usage SANTA MARGARITA FORMATION is adopted herein. Throughout much of the region southwest of the The Caliente Formation of the Caliente Range is San Andreas fault, the Monterey Shale is overlain as thick as 4,200 feet and consists of varicolored by marine sandstone that was named the Santa sandstone, claystone, conglomerate, and four units 32 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA of basalt. It has yielded vertebrate remains diag of the Red Hills penetrated terrestrial beds of the nostic of the following ages of the mammalian Caliente (?) Formation to a depth of 2,910 feet, chronology (fig. 4): Arikareean, late Oligocene (?) then struck granitic basement. Another well about and early Miocene; Hemingfordian, middle Mio 11 miles northwest of the Red Hills or 2V& miles cene; Barstovian, middle (?) and late Miocene; northwest of Cholame was drilled through terres Clarendonian, late Miocene (?); and Hemphillian, trial sedimentary rocks, presumably of the Caliente Pliocene (Repenning and Vedder, 1961; Vedder and Formation, similar to those in the Red Hills from Repenning, 1965). It is therefore assigned an Oligo depths of 1,950 to 6,523 feet, then entered granitic cene (?), Miocene, and Pliocene age (fig. 7), but it basement. is mostly of Miocene age. About 18 miles southeast of the Red Hills, red The strata of the Caliente Formation that contain sandy beds which intertongue(?) southwestward mammalian faunas assigned to the Arikareean, into the Santa Margarita Formation crop out. Hemingfordian, and early Barstovian ages inter- The widely scattered exposures of the Caliente tongue westward into marine beds that have yielded Formation are probably only a very small part of molluscan faunas diagnostic of the "Temblor Stage" its total areal extent; it is largely covered by and foraminiferal faunas diagnostic of the Sauce- younger formations. This terrestrial unit or facies sian, Relizian, and Luisian Stages in the central probably underlies the southeastern part of Cuyama Caliente Range. The strata that contain mammalian Valley and possibly much of the northeast margin faunas assigned to the late Barstovian, Claren of Carrizo Plain (fig. 12), as suggested by the dis donian, and Hemphillian "ages" are overlain by the tribution of the formation in surface exposures and Quatal Formation and are considered in part if not well sections referred to. If the Caliente Formation in whole correlative with the Santa Margarita For is continuous along this strip, it intertongues south- mation, which is also overlain by the Quatal Forma westward into the Branch Canyon Sandstone and tion south of Cuyama Valley and northwest of Car- was deposited along a coastal plain adjacent to the rizo Plain. If all the upper strata of the Caliente Miocene sea to the southwest. The position of the Formation correlate with the Santa Margarita west margin of the continental facies southwest of Formation, then the Santa Margarita, of late Mio the San Andreas fault is about as postulated by cene age of the marine invertebrate chronology, Hill and Dibblee (1953, p. 446-448) but extends may be in part Pliocene of the mammalian chron farther northwest. The granitic detritus that makes ology. Until the relationship of the mammalian up the Caliente Formation was derived from a "ages" to the marine "ages" and stages is more granitic terrane that presumably lay northeast of precisely known, this problem is unresolved. the San Andreas fault in middle Tertiary time. In the Santa Barbara Canyon area southeast of Cuyama Valley, red beds that underlie the Branch BASALT Canyon Sandstone were named the Pato Red Mem ber of the Vaqueros Formation by English (1916, Exposures of volcanic flows, sills, and dikes of p. 200, pi. XIX), but assigned to the Caliente For olivine basalt are present only in the middle Tertiary mation (by Hill, Carlson, and Dibblee (1958, p. 2995). sedimentary sequence in the Caliente Range and on The latter usage is retained, and the name Pato is the east margin of the La Panza Range (fig. 7). considered obsolete. These beds contain sparse mam Most of the flows are in the Monterey Shale, Branch malian remains that suggest Arikareean age (J. G. Canyon Sandstone, and middle and upper Miocene Vedder, oral commun., 1968). parts of the Caliente Formation of the Caliente In the Red Hills northwest of Carrizo Plain, the Range. Dikes are locally abundant in the Vaqueros granitic basement is overlain by about 3,000 feet of and Simmler Formations near Soda Lake, and sev red to gray coarse boulder-cobble conglomerate of eral sills occur in the Vaqueros Formation. granitic detritus. This conglomerate is questionably In the southeastern Caliente Range, two of three referred to the Caliente Formation and is presum prominent basalt flows ("Triple basalts" of Eaton, ably of middle or late Miocene age, but it may be 1939; Hill and others, 1958, p. 2994; and Vedder in part of early Miocene or Oligocene (?) age. It is and Repenning, 1965) were radiometrically dated overlain by sandstone that has late Miocene fossils by Turner (1970, p. 115): the upper flow was dated and is assigned to the Santa Margarita Formation as about 14.2 and 14.4 million years, and the lower but that could be correlative with the Branch one as about 16.1 million years. Both flows are in Canyon Sandstone. the Branch Canyon Sandstone, which contains a A well drilled for petroleum about 2 miles east "Temblor" fauna and which intertongues eastward UPPER TERTIARY SEDIMENTARY SEQUENCE 33 into the part of the Caliente Formation that con trarily placed at the top of the middle Tertiary tains a "Barstovian" fauna. sedimentary sequence. No type locality was desig nated, but Barbat and Johnson (1933, p. 4-5) stated BITTERWATER CREEK SHALE that this shale unit is "typically exposed" from Marine siliceous shale or mudstone that discon- Little Tar Creek (9 miles south-southeast of Ave- formablyC?) overlies conglomerate of the Santa nal) northwest for 22 miles to Jasper Creek (15 Margarita Formation in the Elkhorn Hills area miles west of Avenal). They assigned this shale southwest of Maricopa on the northeast side of the unit to the uppermost Miocene. The type locality is San Andreas fault was named the Bitterwater Creek herein designated as the exposure in Big Tar Creek Shale (Dibblee, 1962, p. 8-11, pi. 1). It was named (about 5 miles south-southwest of Avenal) in sees. for Bitterwater Creek, 6 miles southwest of Mari 7, 8, and 17, T. 23 S., R. 17 E., where the Reef Ridge copa, the type locality, where as much as 2,000 feet of this shale is exposed and is unconformably over Shale is about 550 feet thick. According to Kleinpell (1938, p. 165), the Reef lain by the Paso Robles Formation. This usage is Ridge Shale contains foraminifers assigned to his adopted herein. Delmontian Stage, of latest Miocene age. His Del- The Bitterwater Creek Shale was thought to be montian Stage is, however, now considered to be of Pliocene (?) age (Dibblee, 1962) because of its part of, and inseparable from, his Mohnian Stage stratigraphic position as indicated; however, it con (R. L. Pierce, oral commun., 1970). Therefore, the tains foraminifers, fish scales, and diatoms diagnos Reef Ridge Shale of the type area is considered by tic of the Mohnian Stage, late Miocene (R. L. Pierce, Pierce to be of late Miocene age (Mohnian Stage). oral commun., 1967; Vedder, 1970). This age is the This age assignment, however, has not yet been same as that of the Belridge Diatomite Member of doubtlessly ascertained, as it may range into early the Monterey Shale, but the Bitterwater Creek Shale Pliocene. is stratigraphically higher (fig. 8). Clay shale correlative with the Reef Ridge Shale The relationship of the Bitterwater Creek Shale does not crop out in the Temblor Range. Under the to the unnamed Pliocene marine clastic sediments alluviated area to the east, however, wells penetrate to the northwest, which were formerly included in between the Etchegoin Formation and Monterey the Bitterwater Creek Shale (Dibblee, 1962, pi. 1), Shale a shale unit from 150 to 900 feet thick that is is not clear because of insufficient exposures and referred to the Reef Ridge Shale by petroleum geolo structural complications. North of the Elkhorn Hills gists. This shale unit was considered to be late Mio the Bitterwater Creek Shale intertongues northwest cene and possibly early Pliocene in age and corre ward into unfossiliferous sandstone with siliceous lated with both the Reef Ridge Shale of Reef Ridge shale pebbles. This sandstone is similar to that of and the Belridge Diatomite Member of the Monterey the unit mapped as unnamed marine sediment, of Shale in the Temblor Range (Foss and Blaisdell, early Pliocene age. If the sandstones are the same, 1960, p. 36). Correlation with the Reef Ridge Shale the Bitterwater Creek Shale is equivalent to at is probably valid because of its similar stratigraphic least the lower part of that unit. It is possible, how position and because in some wells, such as in the ever, that the Bitterwater Creek Shale and the un Elk Hills oil field, this unit is gray clay shale (J. C. fossiliferous sandstone are overlapped by that unit Maher, oral commun., 1970) similar to the Reef and if so, are thus older. From the foregoing evi Ridge Shale of Reef Ridge. Correlation with the dence the Bitterwater Creek Shale is considered to Belridge Diatomite Member is considered not valid, be late Miocene (Mohnian) and possibly early Plio as the Reef Ridge Shale is thought to be younger cene in age. than that unit .because of reasons as indicated in REEF RIDGE SHALE the discussion of the Belridge Diatomite Member. In the Reef Ridge and McLure Valley areas, Accordingly, then, the Reef Ridge Shale is probably about 500 feet of soft-weathering claystone is ex correlative with the Bitterwater Creek Shale in the posed that is transitional between the underlying south end of the Temblor Range and is considered Monterey Shale and overlying Etchegoin Formation. to be late Miocene and possibly early Pliocene in age. It was described and named the Reef Ridge Shale by Barbat and Johnson, 1933, p. 239; 1934, p. 1-17) UPPER TERTIARY SEDIMENTARY and by Gester and Galloway (1933, p. 1174-1176). SEQUENCE This usage was adopted by Woodring, Stewart, and DEFINITION Richards (1940, p. 119-122) and Stewart (1946, p. In many places on both sides of the San Andreas 104, pi. 9) and is retained herein. This unit is arbi fault, the middle Tertiary sedimentary sequence is 34 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA overain by shallow-water marine, brackish-water, Anderson (1905, p. 178-181) originally named the and terrestrial sedimentary deposits mainly of Plio entire exposed sequence "Etchegoin Beds," for ex cene age. These deposits are informally designated posures on "Etchegoin ranch, some twenty miles herein as the upper Tertiary sedimentary sequence. northeast of Coalinga" (this plots in the alluvium The age of the sequence may range into early Pleis of San Joaquin Valley), but he called the lower tocene, depending upon the age interpretation of two-thirds "Etchegoin Sands" and the upper third the fossils in the upper part. "San Joaquin Clays." Later, Arnold and Anderson This sequence underlies almost all the San Joaquin (1910, p. 113-114) located this ranch in NW*4 sec. Valley east of the San Andreas fault. West of the 1, T. 19 S., R. 15 E., but designated the type section fault it is restricted to Cuyama Valley, Carrizo of the Etchegoin Formation on Anticline Ridge Plain, and Salinas Valley and is exposed at only a "9 miles north of Coalinga" and defined the forma few places along the margins of this alinement of tion as consisting of sand, gravel, and clay above valleys. The sequence must have accumulated in "the Glycimerus zone." two northwest-trending basins separated by the On the east flank of the Diablo Range south of Temblor Range, against which this sequence thins Coalinga and in the Kettleman Hills, Arnold and from both sides. In each of these basins the sequence Anderson (1908, p. 46-55; 1910, p. 96-124) applied is different in stratigraphy and thickness, as indi the term "Etchegoin Formation" to the upper two- cated subsequently. thirds of this sequence and named the lower third "Jacalitos Formation," which was inferred from DEPOSITS IN THE SAN JOAQUIN VALLEY AREA the fossils to be of late Miocene age. This classifica The upper Tertiary sedimentary sequence of the tion was adopted by Nomland (1916); however, a part of the San Joaquin Valley region of figure 2 year later he (Nomland, 1917, p. 197) abandoned accumulated in what developed (after middle Ter the name Jacalitos Formation because that unit is tiary time) into a large marine embayment, in large lithologically and paleontologically nearly similar to part bounded on the southwest by uplifts that be the Etchegoin, and he applied the term Etchegoin came the Temblor Range and the Diablo Range. Formation or Group to both units and assigned both Because this embayment covered the area that is to the Pliocene. now the San Joaquin Valley, it is commonly called In later years the San Joaquin Clay again became the San Joaquin basin. The upper Tertiary sequence recognized as the upper third of the upper Tertiary deposited in this basin is as thick as 7,000 feet and sedimentary sequence in the west-side oil fields and is composed mainly of fossiliferous interbedded the foothill areas (Reed, 1933, p. 236; Barbat and sandstone, siltstone, and claystone of shallow ma Galloway, 1934). In the Kettleman Hills this unit rine origin with some brackish water and lacustrine was formally defined and mapped as the San Joaquin beds at the top. The sequence crops out in the Reef Formation by Woodring, Stewart, and Richards Ridge and McLure Valley areas of the Diablo Range, (1940, p. 26-28) and adopted by Stewart (1946, and the upper part is exposed in the Kettleman p. 104-105, pi. 9). In both reports the name Jaca Hills. In these areas it lies conformably on the Reef litos Formation was revived for the lower third, Ridge Shale and is overlain conformably by the and Etchegoin Formation retained for the middle Tulare Formation. third of the upper Tertiary sedimentary sequence. Southeast of McLure Valley and Kettleman Hills, They considered all three units to be of Pliocene age. this sedimentary sequence is concealed except for Still later, Adegoke (1969, p. 28-34) recognized a few very small exposures in the foothills of the only a twofold division of this Pliocene sequence. Temblor Range. Subsurface well data from east of He assigned the predominantly sandy lower two- the Temblor Range indicate that this sequence is thirds to the Etchegoin Formation and the largely about 7,000 feet thick, but it thins abruptly south- clayey upper one-third to the San Joaquin Forma westward against previously deformed and eroded tion, as shown in figure 13. Monterey Shale of the Temblor Range. In the oil field subsurface areas east of the Tem blor Range, Pack (1920, p. 44-47, pi. 1) and Wood- TERMINOLOGY ring, Roundy, and Farnsworth (1932, p. 32-39) The stratigraphic nomenclature applied to the applied the term "Etchegoin Formation" to the upper Tertiary sedimentary sequence of the west entire Pliocene marine sedimentary sequence. side of San Joaquin Valley is much confused, as Although the lithology of the upper Tertiary sedi pointed out by Woodring, Stewart, and Richards mentary sequence is generally similar throughout, (1940, p. 26-27). In the area north of Coalinga, it is proposed to adopt the terminology proposed by "d S Etchegoin beds H- Q. OVO (D-i Etchegoin Sands San Joaquin Clays i 3 & to > q § go-o Jacalitos Formation Etchegoin Formation ~z E I 0 ? Q. 2 ^ O Etchegoin Formation or Group a !^I 53" Q. r Etchegoin Group VO (D to (D Jacalitos Formation San Joaquin 00 Q. ! Clay o _ 0 San Joaquin Jacalitos Etchegoin 10 Q. Clay -h ^ DO O 0) ,_. 0)_ -i San Joaquin Etchegoin Sand Clay ^^ 0) 3 ^ o San Joaquin 1-1 (? ^ ?0 (S O Jacalitos Formation Etchegoin Formation ^ g P 0 ? 0- Formation San Joaquin Etchegoin Formation =! Formation ^~ (D (D G Blue sandstone Io W \ /\ 7\ -^ \ / \ / \ San Joaquin § Etchegoin Formation \/ \ v V Formation !^ S8 aoNanbas AnviNawiaas 36 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA Adegoke (1969, p. 28-34) in dividing the sequence ranch" (in T. 19 S., R. 15 E.) north of Coalinga. into the Etchegoin and San Joaquin Formations He did not designate a type section, but Arnold and (fig. 13). The unit formerly called "Jacalitos For Anderson (1910, p. 113) stated: "The nearest local mation" is abandoned because it is neither litho- ity to the Etchegoin ranch for which a description logically nor paleontologically distinct from that or section was given is 9 miles north of Coalinga, called Etchegoin Formation. The lower two-thirds and this may therefore be taken as the type sec of this sequence is a series of alternating friable tion." But on their map (Arnold and Anderson, marine sandstones and siltstones and is designated 1910, pi. 1) this "locality" plots several miles west as the Etchegoin Formation, whereas the upper one- of what they mapped as the Etchegoin Formation. third is mainly marine to brackish-water mudstone From this confusion it may be said that the type and is designated as the San Joaquin Formation, as section is within T. 19 S., R. 15 E., north of Coa shown in figure 14. linga, but its exact designation will not be made until that; area, which is far north of the area of figure 2, is more carefully mapped. AGE FORMATION [SEQUE NCE The most complete and best exposed section, which ' ^ «» - « *--%»OoOOO»»-_.._. (A is herein designated as the reference section, is that So, >*i «/> c 0) (A 'M - 0 <9 0 ------_.. fossils. This unit corresponds roughly to the unit - - - . . . - - o o » . . . formerly called Jacalitos Formation by earlier workers (fig. 13). The upper part (Upper Blue Miocene formations Sandstone Member of Adegoke, 1969, p. 28), about 1,700 feet thick, is similar to the lower part; how FIGURE 14. Valley deposits and upper Tertiary sedimentary ever, sandstones predominate and are somewhat sequence of the San Joaquin Valley area along east side coarser and commonly pebbly and (or) fossiliferous, of the southeastern part of the Diablo Range, Kettleman and many of them are blue. This unit corresponds Hills, and the Temblor Range. roughly to the formerly restricted Etchegoin For mation of Stewart (1946, p. 105, pi. 9). It is similar ETCHEGOIN FORMATION to and nearly equivalent to the "blue bed fades" The Etchegoin Formation, as redefined by Nom- mapped farther northwest by Rose and Colburn land (1917), Barbat and Galloway (1934), and (1963, p. 33). Other places where this unit is ex Adegoke (1969, p. 26-28), is a series of semifriable posed are in McLure Valley and Kettleman Hills. sandstone and interbedded siltstone, claystone, and On the geologic map (Dibblee, 1973b) only parts minor pebble conglomerate, all deposited under of the Upper Blue Sandstone Member of Adegoke shallow-water marine conditions and presumably of (1969, p. 28) that are composed predominantly of Pliocene age. In a few places it contains thin strata blue sandstone are mapped separately from the rest of tuff. In the Reef Ridge it is about 5,200 feet of the Etchegoin Formation (fig. 14). In the Reef thick, overlies the Reef Ridge Shale or the Mon- Ridge area there are several blue sandstone units, terey Shale, and is overlain by the San Joaquin some as thick as 500 feet. Southeastward along Formation. strike all thin out or lose their distinctive blue The type locality of the Etchegoin Formation has color east of the Pyramid Hills. In McLure Valley not been clearly designated. The formation was the whole upper part of the Etchegoin Formation named by F. M. Anderson (1905) for "its char is composed of unfossiliferous massive blue sand acteristic development in the vicinity of Etchegoin stone, about 1,500 feet thick. In the Kettleman Hills UPPER TERTIARY SEDIMENTARY SEQUENCE 37 (North and Middle Domes) several thin blue sand The San Joaquin Formation in the Kettleman stone strata are present. Hills contains marine, brackish-water, and lacus The blue sandstones are medium grained and trine fossils considered to be of late Pliocene age commonly contain pebbles of black and variegated by Woodring, Stewart, and Richards (1940, p. 103). chert and andesite. The blue color of the sandstone They reported (1940, p. 97-98) mammalian fossils is the effect of a thin blue coating on the grains. from the "Pecten zone" about 600 feet below the The Etchegoin Formation of the Reef Ridge and top of this unit. These were considered by Durham, Kettleman Hills areas contains abundant marine Jahns, and Savage (1954, p. 69) to be of Blancan mollusks and echinoids of Pliocene age (Woodring age or late Pliocene and early Pleistocene age and and others, 1940, p. 102-103). In the Kettleman by Hibbard, Ray, Savage, Taylor, and Guilday Hills (North Dome) and at a locality 10-12 miles (1965, p. 512) to be early Blancan age or late north of Coalinga, a few mammalian remains from Pliocene. Adegoke (1969, p. 51) suggested that part the upper part of the Etchegoin Formation are or all of the San Joaquin Formation may be of assigned to the late Hemphillian age, Pliocene (D. Pleistocene age. In the Reef Ridge foothills the San E. Savage, written commun. to C. A. Repenning, Joaquin Formation contains molluscan fossils that 1968). In the Reef Ridge area, the few molluscan Addicott (oral commun., 1968) considered to be of fossils from the lower part of the Etchegoin Forma late Pliocene age. The unit is tentatively assigned a tion are considered to be early Pliocene, and those late Pliocene age, but could range into the Pleisto from the upper part are considered to be late Plio cene, depending on the interpretation of the Plio cene (W. O. Addicott, oral commun., 1969). cene-Pleistocene boundary. SAN JOAQUIN FORMATION DEPOSITS IN THE SALINAS VALLEY CUYAMA VALLEY AREA In the Kettleman Hills the San Joaquin Forma tion, as mapped by Woodring, Stewart, and Richards The upper Tertiary sedimentary sequence of the (1940, p. 26-28, pi. 1), is from 1,200 to 1,800 feet southeastern part of Salinas Valley, Carrizo Plain, thick and is mainly gray soft claystone, siltstone, Caliente Range, and Cuyama Valley is as thick as and fine-grained sandstone. The base was taken as 5,000 feet, but generally thinner. It accumulated in the base of a 50-foot-thick bed of gray to blue sand what developed after Miocene time into a large stone and pebble conglomerate (Cascajo Conglom troughlike basin between the Temblor Range uplift erate Member of Woodring and others, 1940, p. on the northeast and an extensive uplift to the 49-53). The San Joaquin Formation overlies the southwest that evolved into the Santa Lucia, La Etchegoin Formation and grades upward into the Panza and Sierra Madre Mountains (fig. 2). This Tulare Formation. The type locality of the San trough apparently extended northwestward through Joaquin Formation is on the northeast flank of Ket Salinas Valley and may therefore be referred to as tleman Hills, in sec. 23, T. 22 S., R. 18 E., 8 miles the Salinas basin. Most of the upper Tertiary sedi east of Avenal (fig. 1), as suggested by Barbat and mentary sequence lies southwest of the San Andreas Galloway (1934, p. 478-480); however, Woodring, fault; a small part is on the northeast side of the Stewart, and Richards (1940, p. 27) suggested a fault in a narrow strip between the fault and the better standard section 3 miles northwest in sec. 8, Temblor Range uplift. T. 22 S., R. 18 E. The upper Tertiary sedimentary sequence is ter In the foothills north of Reef Ridge, the San restrial, except under Salinas Valley and in part of Joaquin Formation is about 2,000 feet thick and is the strip on the northeast side of the San Andreas similar to its exposure in Kettleman Hills. The base fault, where it is marine. In the central parts of the is taken as a thin pebble bed that overlies blue Salinas basin, this sequence conformably overlies sandstone of the Etchegoin Formation. The San the Santa Margarita or Caliente Formation, but Joaquin Formation grades upward into the Tulare along the flanks, especially the southwestern flank, Formation through interbeds of conglomerate simi it lies unconformably on all older formations, includ lar to that of the Tulare Formation. Southeastward ing the crystalline rocks. Where exposed, this se along strike, the contact with the Tulare Forma- quence is unconformaibly overlain by the Paso Robles ion becomes difficult to map because the upper 1,200 Formation. feet of the San Joaquin Formation contains increas UNNAMED MARINE SEDIMENTS ing amounts of sandstone and many layers of shale- Several test holes drilled for petroleum in the pebble conglomerate, a composition like that of the Shandon area of the Salinas Valley southwest of Tulare Formation. the San Andreas fault passed through as much as 38 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA 2,000 feet of marine sandstone and siltstone of malian remains diagnostic of Hemphillian age, Plio probable Pliocene age below the Paso Robles Forma cene (Savage, 1957, p. 1845), and beds about 1,600 tion and above the Santa Margarita Formation. feet above the base of the overlying Morales Forma Because of its comparable age and stratigraphic tion contain a few mammalian remains of Blancan position, this unit may be equivalent to the Pancho age (James, 1963, p. 11; Repenning and Vedder, Rico Formation, as redefined by Durham and Addi- 1961). The relationship of the Quatal Formation to cott (1964, p. E4; 1965, p. A2-A5) in Salinas the Pliocene (?) marine sediments of the Shandon Valley northwest of figure 2. area to the northwest is concealed, but the Quatal is In the narrow strip on the northeast side of presumably younger. Because of its stratigraphic the San Andreas fault east of Soda Lake is exposed position, the Quatal Formation is herein inferred to about 2,000 feet of marine sandstone that overlies be of Hemphillian age and is assigned to the Plio conglomerate of the Santa Margarita Formation cene. and grades laterally northward and upward into the MORALES FORMATION terrestrial Morales Formation. The relationship of In the Cuyama Valley, Caliente Range, and in the this sandstone to the Bitterwater Creek Shale is area northwest of Carrizo Plain is exposed a de discussed under that formation. This marine sand formed valley deposit, as much as 5,000 feet thick, stone unit contains early Pliocene mollusks (Arnold of light-gray gravel, sand, and silt that conformably and Johnson, 1910, p. 89; W. 0. Addicott, oral overlies the Quatal Formation and unconformably commun., 1967). It may be correlative with the laps onto the middle Tertiary sedimentary sequence. marine unit in the Shandon area described pre This valley deposit was named the Morales Member viously and also with part of the lithologically simi of the Santa Margarita Formation by English (1916, lar Etchegoin Formation of San Joaquin Valley and p. 203, pi. XIX) for Morales Canyon (10 miles north the Diablo Range. west of New Cuyama), the type locality. This deposit was redefined as a formation by Hill, Carlson, and QUATAL FORMATION Dibblee (1958, p. 2990, 2996-2998) because it differs In the eastern Caliente Range, red beds of the lithologically from the Santa Margarita Formation Caliente Formation are overlain conformably by as and in the type locality in unconformably overlies much as 700 feet of lacustrine gray claystone. This the Santa Margarita Formation with angular dis claystone is believed to correlate, on the basis of cordance. The usage of Morales Formation of Hill, similar lithology and stratigraphic position, with Carlson, and Dibblee (1958) and Vedder (1970) is the Quatal Formation named by Hill, Carlson, and retained herein. Dibblee (1958, p. 2996-2997) for Quatal Canyon The Morales Formation was inferred to be of Plio near the type locality, in the Cuyama badlands south cene age by Hill, Carlson, and Dibblee (1958, p. east of the Caliente Range and beyond the southeast 2996-2998) on the basis of its stratigraphic position border of figure 2. This name is herein adopted for above the Quatal Formation and Miocene strata and this claystone in both exposures. because of its unconformable relationship below The Quatal Formation, which conformably under equivalents of the Paso Robles Formation in western lies the terrestrial Morales Formation, is exposed at Cuyama Valley and eastern Caliente Range and at only a few places other than in the Caliente Range. San Juan Creek northwest of Carrizo Plain. In the Cuyama badlands it is composed of about 400 A tooth of Equus (Pleisohippus) sp. (large feet of reddish-brown claystone and gypsum that horse), considered diagnostic of Blancan age (Plio overlies the Caliente Formation. South of Cuyama cene or Pleistocene) of the vertebrate chronology, Valley it is composed of 200-400 feet of white sand was found near the middle of the 5,000-foot-thick stone and red clay that disconformably overlies the Morales Formation in the eastern Caliente Range Santa Margarita Formation and Branch Canyon (Vedder and Repenning, 1965; Vedder, 1970). The Sandstone. In San Juan Creek, northwest of Carrizo profound deformation of this formation, however, Plain, about 200 feet of gray clay assigned to the as compared to the much less deformed uncon Quatal Formation disconformably overlies the Santa formably overlying Paso Robles Formation indicates Margarita Formation. that the Morales Formation probably is late Plio The Quatal Formation was presumed by Hill, Carl- cene in age, to which it was assigned by Vedder son, and Dibblee (1958, p. 2996) to be of late Mio (1970). cene age because of its stratigraphic position. In the In the Panorama Hills and southwestern foothills Caliente Range the uppermost beds of the Caliente of the Temblor Range just northeast of the San Formation that underlie the Quatal contain mam Andreas fault, as much as 2,500 feet of terrestrial VALLEY DEPOSITS 39 gravel named Panorama Hills Formation by Dibblee named Pliocene marine sediments (Pancho Rico(?) (1962, p. 8, pi. 1) gradationally overlies sandstone Formation) as indicated by well logs. In the La of the unnamed marine sediments and is uncon- Panza Range and Red Hills, this valley deposit thins formably overlain by the Paso Robles Formation. and unconformably laps over the previously de The name Panorama Hills Formation is herein formed middle Tertiary sedimentary sequence onto abandoned, and this unit is assigned to the Morales the crystalline basement complex. Formation because it is of similar lithology and is Under the Carrizo Pain, the Paso Robles Forma probably in large part correlative. Presumably this tion is as thick as 2,000 feet near the San Andreas valley deposit accumulated in the same basin as fault as indicated from well logs, and is composed the Morales Formation now exposed in the Caliente largely of shale-pebble gravel, sand, and clay, de Range and Cuyama Valley. rived mainly from the Temblor Range. Southwest- VALLEY DEPOSITS ward this valley deposit thins and buttresses out against previously deformed Morales and Quatal DEFINITION Formations and the middle Tertiary sedimentary Alluvial deposits of Pleistocene and possibly late sequence of the Caliente Range. Pliocene age form the uppermost and youngest At and near the southeast end of the Caliente thick sedimentary unit of the map area. These are Range and southwest of the San Andreas fault, the informally designated herein as valley deposits. Paso Robles Formation ("deformed fanglomerate They accumulated in the San Joaquin and Salinas from eastern sources" of Vedder and Repenning, basins after the sea completely withdrew from this 1965, and "deformed alluvial deposits" of Vedder, region near or at the end of Pliocene time. These 1970) is as thick as 1,000 feet and is unconformable basins thereby became valleys, separated by the on previously deformed lower, middle, and upper Temblor-Diablo Range uplift, which was rising on Tertiary sequences, including the Morales Forma the northeast side of the San Andreas fault. The tion. The Paso Robles Formation is there composed valley deposits southwest of this uplift are com of gravel and some landslide debris of rocks exposed monly called the Paso Robles Formation; these in the San Emigdio Mountains across the fault, but accumulated in a long valley that extended from now is some 20 miles southeast of this area, owing what is now the Salinas Valley southeastward to that much strike-slip on the fault since deposi through Carrizo Plain into Cuyama Valley. The tion of this detritus. valley deposits northeast of the Temblor-Diablo Northeast of the San Andreas fault, the Paso Range uplift are commonly called the Tulare Forma Robles Formation is as thick as 2,000 feet and tion, and they accumulated in the San Joaquin Val more adjacent to the fault, but thins out rapidly ley. northeastward against the Temblor Range. It un PASO ROBLES FORMATION conformably overlies rocks of the Temblor Range, Dissected locally deformed valley deposits in up including the Morales Formation, and was derived per Salinas Valley were named the Paso Robles For entirely from the Temblor Range. mation by Fairbanks (1898, p. 565-566) for expo In Cuyama Valley, equivalents of the Paso Robles sures near Paso Robles (fig. 1). This name has since Formation are thought to be the old dissected been applied to these deposits beyond the Paso locally deformed alluvial fan deposits, such as sev Robles area by Fairbanks (1904), Arnold and John eral on the southwest side of the Caliente Range and son (1910, pi. 1), Bramlette and Daviess (1944), one southwest of New Cuyama. These deposits are Dibblee (1962, p. 6-10, pi. 1), and Durham (1963, as thick as 600 feet and are composed of coarse 1964, 1966) and is used herein. locally derived detritus. In the Salinas Valley lowland area north of the The top of the Paso Robles Formation, where La Panza Range, the Paso Robles Formation is as preserved from erosion, is a surface of deposition, much as 1,500 feet in exposed thickness; it attains or an old valley surface that was never buried. a total maximum thickness of more than 4,000 feet Carrizo Plain, where it is preserved under a thin in the subsurface west of Shandon as indicated cover of alluvium, is a remnant of this former very from well logs. In this lowland area this valley extensive valley surface of deposition. To the north deposit is composed of pebble gravel, sand, and west and west this old valley surface becomes in clay, derived from the La Panza Range and from creasingly dissected and largely destroyed by down- mountains west of Salinas Valley. In the subsurface cutting stream channels of the present Salinas River near Shandon it conformably (?) overlies the un drainage system. Along its margins this old valley 40 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA surface of deposition blends into the old erosion TULARE FORMATION surface of the La Panza, Caliente, and Temblor Locally deformed dissected valley deposits com Ranges as the Paso Robles Formation thins out posed of gravel, sand, and silt in the hills on the against those previously elevated areas. southwest side of the San Joaquin Valley near The age of the Paso Robles Formation can only Coalinga were named Tulare Formation by Ander- be inferred from its stratigraphic position and son (1905, p. 181) for nearby Tulare Lake. No type from geomorphic relations because, except in one locality was then designated, but Woodring, Stewart, place, no diagnostic fossils have been found. This and Richards (1940, p. 13) suggested the exposures formation has been variously inferred to be Plio on the northeast flank of the northern part of Kettle- cene, Pleistocene, or Pliocene and Pleistocene in age. man Hills North Dome as the type section. The Durham (1966, p. B22) and Galehouse (1967, p. name Paso Robles Formation was also applied to 955-956) considered it to be Pliocene and possibly these valley deposits by Anderson and Pack (1915, Pleistocene in age because of the apparent inter- pi. 1) and to those in the Temblor Range by Pack tonguing relationship with the underlying marine (1920, pi. II, p. 47-52). These deposits in the Tem Pancho Rico Formation (lower Pliocene) east and blor Range, however, were included earlier by southeast of King City. In that part of Salinas Val Arnold and Johnson (1910, pi. 1) in a unit they ley (northwest of fig. 2), however, the Paso Robles named McKittrick Formation. These valley sedi Formation is thin, and some of the lower beds into ments were redesignated the Tulare Formation by which marine beds intertongue may be equivalent Woodring, Roundy, and Farnsworth (1932, p. 16- to the Morales or Quatal Formations farther south 30), Dibblee (1962, p. 8-10, pi. 1), and Foss and east. Blaisdell (1968 p. 35) because, even though they The Paso Robles Formation must be at least in are lithologically similar to and occupy the same part of Pleistocene age because its top surface of stratigraphic position as does the Paso Robles For deposition, which blends into the Pleistocene erosion mation, they were deposited in a different basin or surface of the adjacent mountains where this sur valley. This usage is retained herein. face is cut on units as young as the Morales Forma In the foothills of the Diablo Range and in the tion, is in large part preserved, whereas no surface Kettleman Hills, the Tulare Formation is about of deposition of any Tertiary formation remains 2,700 feet thick and grades downward into the San unburied and uneroded. The angular unconformable Joaquin Formation. Well data in the subsurface of relationship of the Paso Robles Formation to all the Elk Hills, Buena Vista Hills, and east of the older units, including the Morales Formation of late Temblor Range indicate that it is similar. In the Pliocene age, suggests that all the Paso Robles For foothills of the Temblor Range it thins out west mation in areas in which this relationship exists is ward against the unconformably underlying Etche- of Pleistocene age. goin Formation and Monterey Shale. The top of The single locality in which fossils were found the Tulare Formation is a valley surface of deposi in the Paso Robles Formation is 2 miles east of tion that forms the present undissected surface of Atascadero in a roadcut about 300 feet west of San Joaquin Valley under a thin mantle of alluvium middle of west line of sec. 7, T, 28 S., R. 13 E. At but is severely dissected, though partly preserved, that place, brackish-marine mollusks were found where it is elevated by deformation in the Elk Hills, (by J. S. Galehouse) in shale-pebble gravel about Buena Vista Hills (east of Taft), and foothills of 20 feet above the base of the Paso Robles Forma the Temblor Range. tion. W. O. Addicott (written commun., 1971) con The age of the Tulare Formation is inferred to sidered them probably Pliocene, possibly middle be late Pliocene and Pleistocene (Arnold and Ander Pliocene. Also found at this locality, and in basal son, 1910, p. 140, 154; Pack, 1920, pi. II; Woodring cobble gravel of this formation within 3 miles south and others, 1932, p. 27, and 1940, p. 104; Stewart, east of Santa Margarita, are cobbles with mollusk- 1946, p. 105; Wahrhaftig and Birman, 1965, p. 314r- bored holes. 316) or Pleistocene (Goudkoff, 1943, p. 248-249; Although the Paso Robles Formation is generally McMasters, 1947, fig. 34; Foss and Blaisdell, 1968, regarded as Pliocene and Pleistocene (?) in age, the p. 35). A few mammalian fossils found in the San formation within the area of figure 2 is considered Joaquin Formation just below the base of the Tu by the writer to be of Pleistocene age and in places lare Formation in the Kettleman Hills and near partly of probable late Pliocene age because of the McKittrick are diagnostic of the Blancair age, late stratigraphic relations and fossil data as indicated. Pliocene or Pleistocene (C. A. Repenning, oral SURFICIAL DEPOSITS 41 commun., 1968). On the basis of diatom studies, sources on the northeast side (Hill and Dibblee, the Tulare Formation is considered to be of Plio- 1953, p. 446; Dibblee, 1973t>). cene and Pleistocene age (K. E. Lohman, written The Pliocene marine sediments (Pancho Rico(?) commun., 1968). Formation and its equivalent) on the northeast side The Tulare Formation within the area of figure 2 of the fault extend some 50-60 miles farther south is probably correlative with most of if not all the east than they do on the southwest side, suggesting Paso Robles Formation on the basis of its similar a right-lateral shift of that amount since they were lithology, stratigraph ic position, and geomorphic deposited. relations and is likewise tentatively assigned a late The spectacular difference in stratigraphy of the Pliocene (?) and Pleistocene age. middle Tertiary sedimentary sequence on opposite sides of the fault, with sudden changes of fades at SURFICIAL DEPOSITS the fault as shown in figure 12, is almost certainly Surficial deposits consist of older alluvium, allu due to lateral juxtaposition of once distant areas. vium, and landslides. These deposits are generally The juxtaposition of the all-marine (in part undeformed, except along or near the San Andreas bathyal) fades of the northeast block against coarse fault. They are generally unconformable on older terrestrial facies, which in large part grades later formations, except in much of the San Joaquin ally westward into shallow marine facies on the Valley and Carrizo Plain, where they may be con southwest block, is difficult to account for otherwise. formable on the Tulare and Paso Robles Forma A right-lateral offset of about 65 miles on the tions where these formations are undeformed. fault since late Miocene time was estimated by Hill The older alluvium, which is as thick as 400 feet and Dibblee (1953, p. 446-448) from the offset on and includes terrace deposits, is dissected where the fault of the transition facies zone where the elevated. At the tar seeps a mile south of McKit- terrestrial sediments grade laterally westward into trick, terrace sands yielded a large mammalian marine sediments. On the northeast block this zone fauna (Schultz, 1938) of Rancholabrean age late is in the San Emigdio Mountains (southeast of Pleistocene (C. A. Repenning, oral commun., 1969). Maricopa, fig. 1); on the southwest block, it is The alluvium forms a thin cover, generally less some 100 miles farther northwest, just northwest than 100 feet thick, on the valleys and flood plains of Cholame, suggesting a right-lateral displacement of canyons. The alluvium and landslides are mainly of that amount. Further evidence suggesting that of Holocene age, but may be in part latest Pleisto much displacement is the occurrence, in the upper cene, depending upon the interpretation of when Miocene Santa Margarita Formation of the Temblor the Holocene started. Range northeast of the fault, of landslide (?) masses and coarse detritus of crystalline basement rocks RELATIONSHIP OF SEDIMENTARY presumably derived from those rocks in the Gabilan SEQUENCES TO THE SAN Range (north of King City, fig. 1) southwest of the ANDREAS FAULT fault but now more than 80 miles to the northwest It may be noted throughout this report that the (Dibblee, 1962, p. 8). This post-Miocene right- successively older sedimentary sequences are in lateral displacement may be as much as 150 miles, creasingly different on opposite sides of the San as inferred by Huffman (1970, p. 105-106) from Andreas fault and that the basement complex upon matching the coarse conglomerate and breccia of which they rest is totally different. This condition this formation in the Temblor Range with their appears to be the result of cumulative right-lateral probable bedrock source in the Gabilan Range west displacement on this fault since Cretaceous (or of the San Andreas fault. Jurassic) time, along which areas of dissimilar Right-lateral offset of some 175 miles since early older sequences and rocks have been juxtaposed, Miocene time was suggested by Hill and Dibblee almost exactly as inferred by Hill and Dibblee (1953, p. 448-449) on the basis of a similar assem (1953). blage of volcanic rocks and terrestrial and marine In the environs of the Carrizo Plain, it was found sedimentary rocks of early Miocene age in the that the Paso Robles Formation on the northeast northern Gabilan Range on the southwest side of side of the San Andreas fault and also just south the fault and in the San Emigdio Mountains on the west of it is composed of detritus derived from the northeast side. Radiometric age dates of 21.5 million mountains on the northeast side and that these years obtained from the volcanic rocks in both areas detrital sediments on the southwest side have been by D. L. Turner (1970, p. 101; oral commun., shifted some 10-15 miles northwest from their 1970) reaffirm this inferred offset. 42 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA The lower Tertiary and Cretaceous sedimentary Arnold, Ralph, and Johnson, H. R., 1910, Preliminary report sequences, although composed almost entirely of on the McKittrick-Sunset oil region, Kern and San Luis marine clastic rocks, are very unlike in stratigraphy, Obispo Counties, California: U.S. Geol. Survey Bull. 406, 225 p. thickness, and age range on opposite sides of the Atwill, E. R., 1935, Oligocene Tumey formation of California: fault within the region of figure 2. This condition Am. Assoc. Petroleum Geologists Bull., v. 19, no. 8, p. must also be the result of juxtaposition along the 1192-1204. fault of areas once far distant. To ascertain Hill Bailey, E. H., Irwin, W. P., and Jones, D. L., 1964, Fran and Difoblee's (1953, p. 448-449) estimated right- ciscan and related rocks, and their significance in the lateral offset on the fault of possibly 225 miles since geology of western California: California Div. Mines and Geology, Bull. 183, p. 1-177. Eocene time, 320 miles since Cretaceous time, and Bailey, W. C., 1939, Wasco oil field [California] California 350 miles since Jurassic time, it is necessary to go Oil Fields Summ. Operations, v. 24, no. 3, p. 66-71 far beyond the borders of figure 2, which is also [1941]. beyond the scope of this report. Bandy, O. L., and Arnal, R. E., 1969, Middle Tertiary basin It may be concluded that the stratigraphy of the development, San Joaquin Valley, California: Geol. Soc. region within figure 2 is closely related and greatly America Bull., v. 80, p. 783-819. affected by movements on and near the San Andreas Barbat, W. F., and Galloway, John, 1934, San Joaquin clay, California: Am. Assoc. Petroleum Geologists Bull., v. fault and that the available evidence suggests that 18, no. 4, p. 476-499. this fault was active, either recurrently or continu Barbat, W. F., and Johnson, F. L., 1933, Stratigraphy and ously, since Jurassic or Cretaceous time. foraminifera of the Reef Ridge shale, upper Miocene, In summary, it may be said that the northeast California [abs.]: Pan-Am. Geologist, v. 59, no. 3, p. block is one of oceanic basement of eugeosynclinal 239; also, 1934, Jour. Paleontology, v. 8, no. 1, p. 1-17. sedimentary and mafic igneous rocks overlain by Blake, W. P., 1855, Notice of remarkable strata containing the remains of Infusoria and Polythalmia in the Ter four sequences of bathyal to shallow-water marine tiary formation of Monterey, California: Acad. Nat. sedimentary rocks, whereas the southwest block is Sci. Philadelphia Proc., v. 7, p. 328-331. one of continental basement of granitic and meta- Bramlette, N. M., and Daviess, S. N., 1944, Geology and oil sedimentary rocks overlain unconformably by three possibilities of the Salinas Valley, California: U.S. Geol. sequences of shallow-water marine and terrestrial Survey Oil and Gas Inv. Prelim. Map 24. sedimentary and minor volcanic rocks. It seems evi Chipping, D. H., 1972, Early Tertiary paleogeography of central California: Am. Assoc. Petroleum Geologists dent that the southwest block was shifted north Bull., v. 56, no. 3, p. 480-493. westward relative to and along the northeast block Church, C. C., 1968, Lower Cretaceous Foraminifera of the by many tens of miles of cumulative right-slip on Orchard Peak-Devils Den area, California: California the San Andreas fault during the Cenozoic Era. Acad. Sci., Proc., 4th ser., v. 32, no. 18, p. 523-580, 8 pis. Clark, B. L., 1929, Tectonics of the Valle Grande of Cali REFERENCES CITED fornia: Am. Assoc. Petroleum Geologists Bull., v. 13, Adegoke, O. S., 1969, Stratigraphy and paleontology of the no. 3, p. 199-238. marine Neogene formations of the Coalinga region, Cali Clark, B. L., and Vokes, H. E., 1936, Summary of marine fornia: California Univ. Pubs. Geol. Sci., v. 80, 241 p., Eocene sequence of western North America: Geol. Soc. 13 pis., figs., maps. America Bull., v. 47, no. 6, p. 851-878. Anderson, F. M., 1905, A stratigraphic study in the Mount Clark, L. M., and Cl-ark, Alexander, 1935, The Vaqueros Diablo Range of California: California Acad. Sci. Proc., in the Temblor Range [abs.]: Am. Assoc. Petroleum 3d ser., Geology, v. 2, p. 155-248. Geologists Bull., v. 19, no. 1, p. 137. 1908, A further stratigraphic study in the Mount Clements, T. D., 1950, Geology of Cuyama Gorge, California Diablo Range of California: California Acad. Sci. Proc., [abs.]: Read before Am. Assoc. Petroleum Geologists, 4th ser., v. 3, p. 1-40. Los Angeles, Calif., October 20, 1950. Anderson, F. M., and Martin, Bruce, 1914, Neocene record in Corey, W. H., 1954, Tertiary basins of southern California, the Temblor Basin, California, and Neocene deposits of pt. 8 in chap. 3 of Jahns, R. H., ed. Geology of southern the San Juan district, San Luis Obispo County: Calif. California: California Div. Mines Bull. 170, p. 73-83. Acad. Sci. Proc., 4th ser., v. 4, p. 15-112. Cross, R. K., 1962, Geology of the Carrizo-Cuyama Basin, Anderson, Robert, and Pack, R. W., 1915, Geology and oil in Guidebook to the geology of Carrizo Plain and San resources of the west border of the San Joaquin Valley Andreas Fault, San Joaquin Geol. Soc. and Pacific Sees. north of Coalinga, California: U.S. Geol. Survey Bull. Am. Assoc. Petroleum Geologists and Soc. Econ. Paleon 603, 220 p. tologists and Mineralogists: p. 27-35. Arnold, Ralph, and Anderson, Robert, 1908, Preliminary re Cunningham, G. M., and Barbat, W. F., 1932, Age of produc port on the Coalinga oil district, Fresno and Kings ing horizons at Kettleman Hills, California: Am. Assoc. Counties, California: U.S. Geol. Survey Bull. 357, 142 p. Petroleum Geologists Bull., v. 16, no. 4, p. 417-421. 1910, Geology and oil resources of the Coalinga dis Curran, J. F., 1943, Eocene stratigraphy of the Chico Mar- trict, California: U.S. Geol. Survey Bull. 398, 354 p., 52 tinez Creek area, Kern County, California: Am. Assoc. pis. Petroleum Geologists Bull., v. 27, no. 10, p. 1361-1386. REFERENCES CITED 43 Curtis, G. H., Evernden, J. F., and Lipson, J. I., 1958, Age Durham, J. W., 1942, Reef corals from the California middle determination of some granitic rocks in California by Eocene: California Acad. Sci. Proc., 4th ser., v. 23, no. the potassium-argon method: California Div. Mines Spec. 34, p. 503-510. Kept. 54, 16 p. 1954, The marine Cenozoic of southern California, pt. Cushman, J. A., and Goudkoff, P. P., 1938, New species of 4, in chap. 3 of Jahns, R. H., ed., Geology of southern Pulvinulinella from the California Miocene: Cushman California: California Div. Mines Bull. 170, p. 23-32. Lab. Foram. Research, Contr. v. 14, pt. 1, pi. 1. Durham, J. W., Jahns, R. H., and Savage, D. E., 1954, Cushman, J. A., and Siegfus, S. S., 1942, Foraminifera from Marine-nonmarine relationships in the Cenozoic section the Kreyenhagen Shale of California: San Diego Soc. of California, pt. 7, in chap. 3 of Jahns, R. H., ed., Nat. History Trans., v. 9, no. 34, p. 385-426, pis. 14-19. Geology of southern California: California Div. Mines Dibblee, T. W., Jr., 1962, Displacements on the San Andreas Bull. 170, p. 59-71. rift zone and related structures in Carrizo Plain and Eaton, J. E., 1939, Geology and oil possibilities of Caliente vicinity, in Guidebook to the geology of Carrizo Plain Range, Cuyama Valley and Carrizo Plain, California: and San Andreas fault, San Joaquin Geol. Soc. and California Jour. Mines and Geol., v. 35, no. 3, p. 255- Pacific Sees. Am. Assoc. Petroleum Geologists and Soc. 274. Econ. Paleontologists and Mineralogists: p. 5-12, pi. 1. Eaton, J. E., Grant, U. S., and Alien, H. B., 1941, Miocene of 1968, Geologic map of Temblor Range, San Luis Caliente Range and environs, California: Am. Assoc. Obispo and Kern Counties, California, in Guidebook to Petroleum Geologists Bull., v. 25, no. 2, p. 193-262. geology and oil fields of west side southern San Joaquin Elliot, W. J., Tripp, Eugene, and Karp, S. E., 1968, Road Valley, Am. Assoc. Petroleum Geologists and Soc. Econ. guides, in Guidebook to geology and oil fields of west Paleontologists and Mineralogists, Pacific Sees., Ann. side southern San Joaquin Valley, Am. Assoc. Petroleum Field Trip, 1968: In pocket. Geologists, Soc. Econ. Geophysicists, and Soc. Econ. 1973a, Geologic map of the Shandon and Orchard Paleontologists and Mineralogists, Pacific Sees., Ann. Peak quadrangles, California, showing Mesozoic and Field Trip, 1968: p. 102-142. Cenozoic rock units juxtaposed along the San Andreas English, W. A., 1916, Geology and oil prospects of Cuyama fault: U.S. Geol. Survey Misc. Geol. Inv. Map 1-788 Valley, California: U.S. Geol. Survey Bull. 621-M, p. [in press], 191-214. 1973b, Regional geologic map of San Andreas and 1918, Geology and oil prospects of the Salinas Val- related faults in Carrizo Plain, Temblor, Caliente, and ley-Parkfield area, California: U.S. Geol. Survey Bull. La Panza Ranges and vicinity, California: U.S. Geol. 691-H, p. 219-250. Survey Misc. Geol. Inv. Map 1-757 [in press]. 1921, Geology and petroleum resources of north Dickinson, W. R., 1963, Tertiary stratigraphic sequence of western Kern County, California: U.S. Geol. Survey the Hancock Ranch area, Monterey and Kings Counties, Bull. 721, 48 p. California, in Guidebook to the geology of Salinas Val Evernden, J. F., Savage, D. E., Curtis, G. H., and James, G. ley and the San Andreas fault, Am. Assoc. Petroleum T., 1964, Potassium-argon dates and Cenozoic mamma Geologists and Soc. Econ. Paleontologists and Mineralo lian chronology of North America: Am. Jour. Sci., v. gists, Pacific Sees., Ann. Field Trip, 1963: p. 47-53. 262, no. 2, p. 145-198. 1966a, Structural relationships of San Andreas fault Fairbanks, H. W., 1898, Geology of a portion of the south system, Cholame Valley and Castle Mountain Range, ern Coast Ranges: Jour. Geology, v. 6, no. 6, p. 551-576. California: Geol. Soc. America Bull., v. 77, no. 7, p. 707-726. 1904, Description of the San Luis quadrangle [Cali fornia] : U.S. Geol. Survey Geol. Atlas, Folio 101, 14 p. 1966b, Table Mountain serpentine extrusion in Cali fornia Coast Ranges: Geol. Soc. America Bull., v. 77, Fletcher, G. L., 1962, The Recruit Pass area of the Temblor no. 5, p. 451-472. Range, San Luis Obispo and Kern Counties, California, Diller, J. S., and Stanton, T. W., 1894, The Shasta-Chico in Guidebook to the geology of Carrizo Plain and San series: Geol. Soc. America Bull., v. 5, p. 435-464. Andreas fault, San Joaquin Geol. Soc. and Pacific Sees. Durham, D. L., 1963, Geology of the Reliz Canyon, Thomp Am. Assoc. Petroleum Geologists and Soc. Econ. Paleon son Canyon, and San Lucas quadrangles, Monterey tologists and Mineralogists: p. 16-20. County, California: U.S. Geol. Survey Bull. 1141-Q, p. Foss, C. D., and Blaisdell, Robert, 1968, Stratigraphy of the Q1-Q41. west side of southern San Joaquin Valley, in Guidebook 1964, Geology of the Cosio Knob and Espinosa Canyon to geology and oil fields of west side southern San quadrangles, Monterey County, California: U.S. Geol. Joaquin Valley, Am. Assoc. Petroleum Geologists, Soc. Survey Bull. 1161-H, p. H1-H29. Econ. Geophysicists, and Soc. Econ. Paleontologists and 1966, Geology of the Hames Valley, Wunpost and Mineralogists, Pacific Sees., Ann. Field Trip, 1968: p. Valleton quadrangles, Monterey County, California: 33-43. U.S. Geol. Survey Bull. 1221-B, p. B1-B53. Gabb, W. M., 1869, Cretaceous and Tertiary fossils: Cali Durham, D. L., and Addicott, W. O., 1964, Upper Miocene fornia Geol. Survey, Paleontology, v. 2, 299 p. 36 pis. and Pliocene marine stratigraphy in southern Salinas Galehouse, J. S., 1967, Provenance and paleocurrents of the Valley, California: U.S. Geol. Survey Bull. 1194-E, p. Paso Robles Formation, California: Geol. Soc. America E1-E7 [1965]. Bull., v. 78, no. 8, p. 951-978. 1965, Pancho Rico Formation, Salinas Valley, Cali Gester, C. G., and Galloway, John, 1933, Geology of Kettle- fornia: U.S. Geol. Survey Prof. Paper 524-A, p. Al- man Hills oil field, California: Am. Assoc. Petroleum A22. Geologists Bull., v. 17, no. 10, p. 1161-1193. 44 STRATIGRAPHY, SOUTHERN COAST RANGES NEAR SAN ANDREAS FAULT, CALIFORNIA Goudkoff, P. P., 1934, Subsurface stratigraphy of Kettle- Geologists, Soc. Econ. Geophysicists, and Soc. Econ. man Hills oil fields: Am. Assoc. Petroleum Geologists Paleontologists and Mineralogists, Pacific Sees., Ann. Bull., v. 18, no. 4, p. 435-475. Field Trip, 1947: p. 100-105. 1943, Correlation of oil field formations on the west Mallory, V. S., 1959, Lower Tertiary biostratigraphy of the side of San Joaquin Valley [California]: California Div. California Coast Ranges: Tulsa, Okla., Am. Assoc. Mines Bull. 118, p. 247-252. Petroleum Geologists, 416 p. 1945, Stratigraphic relations of upper Cretaceous in Marsh, O. T., 1960, Geology of the Orchard Peak area, Cali Great Valley, California: Am. Assoc. Petroleum Geol fornia: California Div. Mines Spec. Rept. 62, 42 p. ogists Bull., v. 29, no. 7, p. 956-1007. Noble, E. B., 1940, Rio Bravo oil field, Kem County, Cali Hamlin, Homer, 1904, Water resources of the Salinas Val fornia: Am. Assoc. Petroleum Geologists Bull., v. 24, no. ley, California: U.S. Geol. Survey Water-Supply and 7, p. 1330-1333. Irrigation Paper 89, 91 p. Nomland, J. O., 1916, Fauna from the lower Pliocene at Hay, E. A., 1963, Age and relationships of the Gold Hill Jacalitos Creek and Waltham Canyon, Fresno County, pluton, Cholame Valley, California, in Guidebook to the California: California Univ. Pubs., Dept. Geology Bull., geology of Salinas Valley and San Andreas fault, Am. v. 9, p. 199-214. Assoc. Petroleum Geologists and Soc. Econ. Paleontolo gists, Pacific Sees., Ann. Field Trip, 1963: p. 113-115. 1917, The Etchegoin Pliocene of middle California: Heikkila, H. H., and MacLeod, G. M., 1951, Geology of Bitter- California Univ. Pubs., Dept. Geology Bull., v. 10, no. water Creek area, Kern County, California: California 14, p. 201-202. Div. Mines Spec. Rept. 6, 21 p. Pack, R. W., 1920, The Sunset-Midway oil field, California; Henny, Gerard, 1930, McLure shale of the Coalinga region, Part 1, Geology and oil resources: U.S. Geol. Survey Fresno and Kings Counties, California: Am. Assoc. Prof. Paper 116,179 p. Petroleum Geologists Bull., v. 14, no. 4, p. 403-410. Page, B. M., 1970, Sur-Nacimiento fault zone of California: Hibbard, C. W., Ray, C. E., Savage, D. E., Tayk>r, D. W., Continental margin tectonics: Geol. Soc. America Bull., and Guilday, J. E., 1965, Quaternary mammals of North v. 81, p. 667-690. America, in The Quaternary of the United States: Reed, R. D., 1933, Geology of California: Tulsa, Okla., Am. Princeton, N. J., Princeton Univ. Press, p. 509-525. Assoc. Petroleum Geologists, 355 p. Hill, M. L., and Dibblee, T. W., Jr., 1953, San Andreas, Big Repenning, C. A., and Vedder, J. G., 1961, Continental verte Pine, and Garlock faults, California a study of the brates and their stratigraphic correlation with marine character, history, and tectonic significance of their dis mollusks, eastern Caliente Range, California, in Short placements: Geol. Soc. America Bull., v. 64, no. 4, p. papers in the geologic and hydrologic sciences, 1961: 443-458. U.S. Geol. Survey Prof. Paper 424-C, p. C235-C239. Hill, M. L., Carlson, S. A., and Dibblee, T. W., Jr., 1958, Rose, R. L., and Colburn, I. P., 1963, Geology of the east- Stratigraphy of Cuyama Valley Caliente Range area, central part of the Priest Valley quadrangle, California, California: Am. Assoc. Petroleum Geologists Bull., v. in Guidebook to geology of Salinas Valley and San 42, no. 12, p. 2973-3000. Andreas fault, Am. Assoc. Petroleum Geologists and Huffman, O. F., 1970, Miocene and post-Miocene offset on Soc. Econ. Paleontologists, Pacific Sees., Ann. Field the San Andreas fault in central California [abs.]: Geol. Trip, 1963: p. 38-45. Soc. America Abs. with Programs, v. 2, no. 2, p. 104-105. San Joaquin Geological Society, 1959, Guidebook, field trip, James, G. T, 1963, Paleontology and nonmarine stratigraphy Chico Martinez Creek area, California, May 9, 1959: 15 of the Cuyama Valley badlands, California; Pt. 1, p., geol. map. Geology, faunal interpretations, and systematic descrip Savage, D. E., 1957, Age of the Caliente Formation, Caliente tions of Chiroptera, Insectivora, and Rodentia: Cali Range, California [abs.]: Geol. Soc. America Bull., v. fornia Univ. Pubs. Geol. Sci., v. 45,154 p. 68, no. 12, pt. 2, p. 1845. Jennings, C. W., 1958, Geologic map of California, Olaf P. Savage, D. E., Downs, Theodore, and Poe, O. J., 1954, Jenkins edition, San Luis Obispo Sheet: California Div. Cenozoic land life of southern California, pt. 6 in chap. Mines Map Sheet. 3 of Jahns, R. H., ed., Geology of southern California: Johnson, H. R., 1909, Geology of the McKittrick-Sunset Dis California Div. Mines Bull. 170, p. 43-58. trict, California [abs.]: Science, v. 30, p. 63-64. Schultz, J. R., 1938, A late Quaternary mammal fauna from Kleinpell, R. M., 1938, Miocene stratigraphy of California: the tar seeps of McKittrick, California: Carnegie Inst. Tulsa, Okla., Am. Assoc. Petroleum Geologists, 450 p. Washington Pub. 487, p. 113-215. Lawson, A. C., 1914, Description of the San Francisco dis trict Tamalpais, San Francisco, Concord, San Mateo Siegfus, S. S., 1939, Stratigraphic features of Reef Ridge and Hayward quadrangles [California]: U.S. Geol. Sur Shale in southern California: Am. Assoc. Petroleum vey Geol. Atlas, Folio 193. Geologists Bull, v. 3, no. 1, p. 24-44. Loel, Wayne, and Corey, W. H., 1932, The Vanqueros Forma Simonson, R. R., and Krueger, M. L., 1942, Crocker Flat tion, lower Miocene of California; Pt. 1, Paleontology: Landslide area, Temblor Range, California: Am. Assoc. California Univ. Pubs., Dept. GeoL Bull, v, 22, no. 3, p. Petroleum Geologists Bull., v. 26, no. 10, p. 1608-1631. 31-410. Smith, H. P., 1956, Foraminifera from the Wagonwheel Louderback, G. D., 1913, The Monterey series in California: Formation, Devils Den district, California: California California Univ. Pubs., Dept. Geol. Bull., v. 7, p. 177- Univ. Pubs. Geol. Sci., v. 32, p. 65-126. 214. Stewart, Ralph, 1946, Geology of Reef Ridge, Coalinga dis McMasters, J. H., 1947, Cymric oil field, Kern County, Cali trict, California: U.S. Geol. Survey Prof. Paper 205-C, fornia, in Field trip guidebook, Am. Assoc. Petroleum p. 81-115 [1947]. REFERENCES CITED 45 Taliaferro, N. L., 1943, Geologic history and structure of the Watts, W. L., 1897, Oil and gas yielding formations of Los central Coast Ranges of California: California Div. Angeles, Ventura and Santa Barbara Counties, Cali Mines BulU 118, p. 119-162. fornia: California State Min. Bur. Bull. 11, 94 p. Thorup, R. R., 1943, Type locality of the Vaqueros Forma Weaver, C. E., chm., and others, 1944, Correlation of the tion [California]: California Div. Mines Bull. 118, p. marine Cenozoic formations of western North America 463-466. [Chart 11]: Geol. Soc. America Bull., v. 55, no. 5, p. Turner, D. L., 1970, Potassium-argon dating of Pacific 569-598. Coast Miocene foraminiferal stages: Geol. Soc. America White, R. T., 1938, Eocene Lodo formation and Cerros mem Spec, Paper 124, p. 91-129. ber of California [abs.]: Geol. Soc. America Proc. for Van Couvering, Martin, and Alien, H. B., 1943, Devils Den 1937, p. 256-257. oil field [California]: California Div. Mines Bull. 118, Wiedey, L. W., 1928, Notes on the Vaqueros and Temblor p. 496-501. Formations of the California Miocene with descriptions Vedder, J. G., 1970, Geologic map of the Wells Ranch and of new species: San Diego Soc. Nat. History Trans., Elkhorn Hills quadrangles, San Luis Obispo and Kern v. 5, no. 10, p. 95-182. Counties, California showing juxtaposed Cenozoic rocks Williams, R. N., 1936, Recent developments in the North along the San Andreas fault: U.S. Geol. Survey Misc. Belridge oil field [California]: California Oil Fields Geol. Inv. Map 1-585. Summ. Operations, v. 21, no. 4, p. 5-16. Vedder, J. G., and Brown, R. D., 1968, Structural and strati- Wilmarth, M. G., 1938, Lexicon of geologic names of the graphic relations along the Nacimiento fault in the United States (including Alaska): U.S. Geol. Survey southern Santa Lucia Range and San Rafael Moun Bull. 896, 2396 p. tains, California, in Dickinson, W. R. and Grantz, Arthur, eds., Proceedings of conference on geologic prob Wood, H. E., chm., and others, 1941, Nomenclature and cor lems of the San Andreas fault system: Stanford Univ. relation of the North American continental Tertiary: Pubs. Geol. Sci., v. 11, p. 243-258. Geol. Soc. America Bull., v. 52, no. 1, p. 1-48. Vedder, J. G., and Repenning, C. A., 1965, Geologic map of Woodring, W. P., Bramlette, M. N., and Kleinpell, R. M., the southeastern Caliente Range, San Luis Obispo 1936, Miocene stratigraphy and paleontology of Palos County, California: U.S. Geol. Survey Oil and Gas Inv. Verdes Hills, California: Am. Assoc. Petroleum Geolo Map OM-217. gists Bull., v. 20, no. 2, p. 125-159. Wagner, H. C., Bartow, J. A., Pierce, R. H., and Dibblee, T. Woodring, W. P., Roundy, P. V., and Farnsworth, H. R.,. W., Jr., 1973, Geologic sections across the San Andreas 1932, Geology and oil resources of the Elk Hills, Cali fault in the Carrizo Plain and the Temblor, Caliente, fornia (including Naval Petroleum Reserve No. 1): and La Panza Ranges and vicinity, California: U.S. U.S. Geol. Survey Bull. 835, 82 p. Geol. Survey Misc. Geol. Inv. Map [in press]. Woodring, W. P., Stewart, R. B., and Richards R. W., 1940, Wahrhaftig, Clyde, and Birman, J. H., 1965, The Quaternary Geology of the Kettleman Hills oil field, California, stra of the Pacific Mountain system in California, in Wright, tigraphy, paleontology, and structure: U.S. Geol. Sur H. E., and Frey, D. G., eds., The Quaternary of the vey Prof. Paper 195, 170 p. United States A review volume for the 7th Congress Young, Umberto, 1943, Republic area of the Midway-Sunset of International Association for Quaternary research: oil field [California]: California Div. Mines Bull. 118, Princeton, N. J., Princeton Univ. Press, p. 299-340. p. 522-525. 0. S. GOVERNMENT PRINTING OFFICE : 1973 O - 495-417