Bulletin No. 309 A> Economic Geology, 91 

B) Descriptive Geoiogy)

DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

CHARLES D. WALCOTT, DIRECTOR

THE

SANTA CLARA VALLEY, PUENTE HILLS 

AND LOS ANGELES OIL DISTRICTS

SOUTHERN CALIFORNIA

GEORGE ROMANS ELDRIDGE

RALPH ARNOLD

WASHINGTON

GOVERNMENT PRINTING OFFICE

1907

CONTENTS.

Page.

PREFACE ................................................................. xi

THE SANTA CLARA VALLEY OIL DiST.ii.iCT, SOUTHERN CALIFORNIA, BY

GEORGE H. ELORIDGE. \

Introduction.............................................................. 1

Acknowledgments.......................................................... 1

Topography............................................................... 1

Geologic formations......................................................... 4

General statement...................................................... 4

Granitic basement..................................................... 5

General character and distribution................................... 5

Topatopa formation..................................................... 5

General character................................................. 5

Distribution...................................................... 7

Age...........:................................................... 7

Occurrence of oil.................................................. 7

Sespe formation........................................................ 7

General character................................................. 7

Lower zone....................................................... 8

led beds.......................................................... 8

General description......................:...................... 8

In the Ojai Valley............................................ 9

South of the Santa Clara........................................ 10

Oil in the red beds............................................ 10

Upper zone........................................................ 10

Relation of upper Sespe beds to Vaqueros shale................... 11

Oil in the upper Sespe beds..................................... 12

Vaqueros formation.................................................... "'12

Age and general character........................................... 12

In the Ojai Valley..............................'...............;.... 13

South of the Santa Clara............................................ 15

Modelo formation....................................................... 17

General character................................................. 17

Lower" sandstone.................................................. 18

Upper sandstone.................................................... 18

Shale in the Modelo................................................. 19

Variation in composition of the Modelo.............................. 19

Supposed Modelo beds in the Ojai Valley and Sulphur Mountain...... 20

Correlat^n of the tipper shaly portion of the Modelo with the Montere^j

shale........................................................... 20

Difficulties of correlation between north and south sides of Santa Clara

Valley.......................................................... 21

Burning of the shale................................................ 22
IV - CONTENTS.

-Geologic formations Continued. Page.

Fernando formation................................................... 22

General character and age..:........................................ 22

Paleontology of the Fernando formation............................. 23

Lower.Fernando fauna.......................................... 24

Middle Fernando fauna........................................ 25

Upper Fernando fauna.......................................... 25

Pleistocene deposits................................................... 28

In the vicinity of Saugus.......................................... 28

At mouth of Sespe Canyon........................................ 28

Conglomerate of Lion Canyon....................................... 28

General structure of district................................................ 29

Introductory statement................................................. 29

Santa Clara Valley......:; ............................................. 29

Region north of the Santa Clara......................................... 30

Region south of the Santa Clara......................................... 35

Oil fields north of the Santa Clara........................................... 36

Ojai Valley fields................................................... 36

Location........................................................ 36

Structure.................................................:.... 36

Oil wells....................................................... 39

Pirie ranch wells........................................... 39

Lion Canyon wells......................................... 40

Langdell, Newmark & Roan wells........................... 40

Whidden-Double wells..................................... 40

Sobra Vista wells........................................... 41

Santa Paula wells. ............................\............ 42

Southern Sulphur Mountain field................................... 42

Location....................................................... 42

'Geology. .................................................... 42

Structure..........................._. ....'....................... 44

Oil wells....................................................... 45

Silver'Thread or Sisar Creek field.................................... 46

>. Location...................................................... 46

. Structure....................................................... 46

Oil wells....................................................... 48

Field south of Santa .Paula Ridge................................... 49

Location................................:..................... 49

Geology and structure.......................................... 49

Oil wells....................................................... 50

Sespe fields.................... 1................................... 51

Location.............................:........................ ' 51

Structure...................................................... 51

Oil wells....................................................... 54

Union Consolidated wells................................. 54

Region of Devilsgate...............;....................-.... 54

Ivers wells................................................. 55

Kentuck wells.............................................. 56

Happy Thought wells...................................... 58

Foot-of-the-Hill or Los Angeles wells......................... 58

Fourfork wells............................................ 60

Tar Creek wells........................................... 61
CONTENTS. V

Oil fields north of the Santa Clara Continued. Page.

Pole Canyon....................................................... 62

Location. ...................................................... 62

Geology and structure. .......................................... 62

Hopper-Piru fields................................................. 64

Location................................... />.................. 64

Structure...................................................... 64

West of Piru Creek................ ^............".......... 64

East of Piru Creek.......................................... 67

 ' Oil wells....................................................... 68

San Cayetano wells......................................... 68

Sunset wells................................................ 69

Fortuna wells.............................................. 69

Nigger Canyon wells....................................... 71

Modelo Canyon wells...................................... 71

Wellsof the Piru Oil and Land. Company...................... 74

Wells of Holser Canyon...................................... 75

Oil fields south of the Santa Clara.......................................... 76

General statement.................................................. 76

Bardsdale field..................................................... 76

Location....................................................... 76

Geology and- structure....... 1................. A ............... 76

Oil wells....................................................... ' 79

Union and Bardsdale crude wells........................... 79

Torrey-Eureka-Tapo fields.......................................... 80

Location...................................................... 80

Geology and structure............................................ 80

Oil wells'....................................................... 86

Torrey. wells............................................... 87

Eureka wells.............................................. 87

Tapo wells................................................. 89

Pico fields........................................................ - 90

Location...................................................... 90

Geology and structure......................................:... 90

Productive fields of the Pico district............................... 93

Oil wells....................................................... 94

Pico Canyon wells.................................. 1...... 94

Dewitt Canyon wells...................................... 95

Towsley Canyon wells..................................... . 95

Wiley Canyon wells........................................ 96

Rice Canyon wells......................................... 96

East Canyon wells......................................... 96

Elsrnere field...................................................... '96

Location...................................................... 96

Geology and structure.......................................... 97

Oil wells............................ '.. ......................... 98

Enterprise, Pearl, and Zenith wells.......................... 98

Elsmere Ridge wells....................................... 99

Elsmere Canyon wells...................................... 99

Nettleton & Kellerman wells................................ 99

Well south of ridge crest................................... 99

Placerita Canyon wells. ....................*................ 100
VI CONTENTS.

THE PUENTE HILLS OIL DISTRICT, SOUTHERN CALIFORNIA, BY GEORGE

H. ELDRIDGE. Page.

Introduction.............................................................. 102

Acknowledgments........................................................... 102

Location and topography................................................... 102

Geology.................................................................. 103

Formations........................................................... 103

Lower Puente shale................................................... 103

Puente sandstone....................... 1............................... 104

Upper Puente shale.......................:............................ 104

Correlation of the Puente formation with the Monterey................... 105

Post-Puente diabase................................................... 106

Fernando formation................................................... 106

Pleistocene............................................................ 107

Structure.................................................................. 108

General structural relations of the fields.................................. 108

Coyote Hills anticline................................................... 109

Geologic relations of oil-bearing strata....................................... 109

Oil fields................................................................. 110

Whittier field......................................................... 110

* Location.......................................................... 110

Geology.......J.................................................. 110

Structure. ........................................................ 112

Oil wells........................................................... 113

La Habra Canyon field................................................ 115

Location..........................................:............... 115

Geology.......................................................... 115

Structure.............................................'............. 116

Oil wells........................................................... 117

Puente field.......................................................... 117

Location........................................../................ 117

Geology.......................................................... 117

Structure.......................................................... 118

Oil wells........................................................... 119

Brea Canyon field...................................................... 120

Location.......................................................... 120

Geology.......................................................... 120

Structure.......................................................... 121

Oil wells....................;...................................... 123

Olinda field........................................................... 125

Location.......................................................... 125

Geology.......................................................... 125

Structure.......................................................... 126

Oil wells........................................................... 131

Chino field............................................................. 132

Conclusions concerning future development.........................;........ 132

Petroleum of the Puente Hills district....................................... 133

Yield and gravity of oil in different fields................................ 133

Factors in yield of wells...........................:................... 133

Associated hydrocarbons...................... r ........................ 134

Storage and transportation.............................................. 134

Utilization of the oil.................................................... 135

Production............................................................ 136

Prices........................................--....-...----..-------- 136

Oil companies in Puente Hills district............... '. ...................... 137
CONTENTS. VIT

THE Los ANGELES OIL DISTRICT, SOUTHERN CALIFORNIA, BY RALPH

ARNOLD. ' Page.

Introduction................... 1.......................................... 138

Acknowledgments.......................................................... 138

Previous knowledge of the region............................................ 138

Location and topography................................................... 142

Geologic formations........................................................ 143

General statement...................................................... 144

Black schist........................................................... 145

Granite................................................................ 145

Puen'te sandstone...................................................... 145

General character..'............................................... 145

Fossils............................................................ 146

Upper Puente shale.................................................... 148

General character................................................. 148

Oil sands.......................................................... 149

Miocene basalt......................................................... 1.50

Fernando formation.................................................... 150

General character................................................. 150

Fossils............................................................ 152

Pleistocene............................. r .............................. 153

General character................................................. 153

Brea deposits.....................'................................ 154

Structure...............................:.................................. 155

General features....................................................... 155

Structure of the oil belt................................................ 156

Joint cracks........................................................... 157

Oil fields. ................................................................. 158

Location.............................................................. 158

Development.......................................................... 158

Eastern field.......................................................... 160

 Location..........:............................................... 160

Topography....................................................... 160

Geology.......................................................... 160

Geology of the wells................................................ 162

Structure............................................................ 163

Development...................................................... 164

Central field.. ........../............................................. 165

Location........................................................... 165

Topography....................................................... 165

Geology............................................................ 165

Geology of the wells. ............................................... 167

Structure.......................................................... 170

Development........... ^......................................... 172

Western field.......................................................... 172

Location............................................................ 172

Topography....................................................... 172

Geology.......................................................... 173

Geology of the wells................................................ 174

Baptist College area............................................ 175

Vicinity of Western avenue and Temple road................... 178

Area one-fourth mile northwest of Temple road and Western

avenue..................................................... 181

Area south of Colegrove......................................... 182

Structure.......................................................... 184
VIII CONTENTS.

Oilfields Continued. Page.

Salt Lake field................................^....................... 186

Location........................,.........................;........ 186

Geology.......................................................... 186

General statement............................................... 186

Oil sands.............................."..................-...... 186

Brea deposits^................................................ 187

Geology of the wells................................................ 187

Area north and northwest of the lagoon........................... 187

Area south and southeast of the lagoon.......................... 191

Structure.......................................................... 193

Development...................................................... 195

Conclusions concerning future development.................................... 196

City fields...........................................;-.-.............. 196

East of Los Angeles River............................................... 196

Southwest and west of Los Angeles...................................... 197

Production................................................................ 198

Storage.................................................................... 198

Transportation............................................................ 198

BIBLIOGRAPHY or SOUTHERN CALIFORNIA OILS .............................. 199

PHYSICAL AND CHEMICAL PROPERTIES OP SOUTHERN CALIFORNIA OILS, 

COMPILED BY RALPH ARNOLD.

Introduction.............................................................. 203

General character of the southern -California oils.............................. 203

Gravity... :...................................-.........'.............'...: 203

Color.................................................:................ 203

Composition.......................................................... 204

Fuel and gas making. ..............................'................. .. 204

Products of refineries. ...............................'. ................. 205

Analyses................................................................:...: 205

FOSSILS or THE OIL-BEARING FORMATIONS OF SOUTHERN CALIFORNIA, 

BY RALPH ARNOLD.

Introduction.................................................:......:..... 219

Plates..................................................................... 221

INDEX. ................................................................... 259
ILLUSTRATIONS.

Pago. 

PLATE I. Geologic map of Santa Clara Valley and adjacent oil fields in Ventura and 'Los Angeles counties.............................. Pocket.

II. A, View across Hopper Canyon to valley of Piru River; B, The

great Topatopa anticline, Sespe oil field...................... 2

' III. Geologic structure sections across Mount Pinos, Tejon, Santa Paula,

and Camulos quadrangles...................................... 28

IV. Geologic structure sections across Camulos, Santa Susana, and Fernando quadrangles............................................ 30

V. Township and. section map of the Santa Clara district, showing

location of oil wells.......................................... 36

VI. A, Flanks of Oak Ridge and the Santa Susana Mountains, show-

. ing post-Pliocene peneplain; B, The Upper Ojai Valley........ 46

VII. A, Santa Paula Canyon; B, Elsmere Hill and oil wells, near Newhall, Los Angeles County..................................... 48

VIII. A, Modelo wells, Modelo Canyon, Ventura County; B, Fortuna

wells, Hopper Canyon, Ventura County....................... 70

IX. A, Overturn in Vaqueros formation, west side of Pico Canyon, 

Los Angeles County; B, Pico anticline, Pico Canyon, Los 

Angeles County............................................. 90

X. Geologic map of the oil fields of Puente Hills.................... 102

XI. Geologic sections across the oil fields of the Puente Hills district.. 108

XII. Township and section'map of the Puente Hills oil district, showing

location of oil wells........................................... 110

XIII. A, Wells along Central Oil Company Murphy Oil Company property line, Whittier field, Los Angeles County; B, Productive 

well in vertical strata, Whittier field, Los Angeles County...... 112

XIV. A, Brea Canyon field, Orange County; B, Characteristic pumping

plant, Whittier field, Los Angeles County...................... 120

XV. A and B, Panorama of the Olinda oil field....................... 124

XVI. Detailed geologic section through Olinda oil field.................. 130

XVII. Chart showing A^ariation in daily production of a group of oil wells in

the Puente Hills district..................................... 134

XVIII. Geologic map of the region of the Los Angeles oil fields............ 144

XIX. Street and section map of the Los Angeles oil fields, showing location of oil wells.............................................. 158

XX. Geologic structure sections across Los Angeles oil fields, Los Angeles

quadrangle.....................;............................ 162

XXI. A, Nodular Miocene sandstone at Los Angeles; B, Typical lower

Miocene sandstone at Los Angeles............................. 166

XXII. A, Eastern oil field, Los Angeles; B, Central oil field, Los Angeles. 168 

XXIII. Salt-Lake field, Los Angeles.................................... 186

IX-
ILLUSTRATIONS.

XXIV. A, Characteristic thin-bedded Pliocene sandstone, Los Angeles oil 

fields; B, Lagoon in the Salt Lake field, Los Angeles, showing 

floating oil and bubbling water caused by escaping gas......... 188

XXV. Eocene Pelecypoda............................................. 223

XXVI. Eocene Pelecypoda and Gasteropoda............................ 225

XXVII. Miocene Pelecypoda and Gasteropoda............................ 227

XXVIII. Miocene Pelecypoda and Gasteropoda............................ 229

XXIX. Miocene Echinoidea and Pelecypoda............................. 231

XXX. Miocene Echinoidea, Pelecypoda, and Gasteropoda.............. 233

XXXI. Miocene Pelecypoda and Gasteropoda............................ 235

XXXII. Miocene Pelecypoda, Gasteropoda, and Crustacea................ 237

XXXIII. Miocene Pelecypoda and Gasteropoda............................ 239

XXXIV. Pliocene pectens...............................................: ,241

XXXV. Pliocene pectens. ............................................... 243

XXXVI. Pliocene pectens................................................. 245

XXXVII. Pliocene areas.................................................. 247

XXXVIII. Pliocene Pelecypoda and Gasteropoda........................... 249

XXXIX. Pliocene Brachiopoda and Pelecypoda.......................... 251

XL. Pliocene Pelecypoda and Gasteropoda.......................... 253

XLI. Tertiary turritellas.............................................. 255

FIG. 1. Index map of portion of southern California........................... 2

2. East-west section across Sespe Canyon above mouth of Tar Creek...... 8

3. North-south section, on north side of Lower Ojai Valley................ 9

4. Sketch map showing location of wells and oil seepages in the northeast

corner of Upper Ojai Valley...................................... 41

5. Sketch map showing location of Ivers wells, with relation to anticlinical

axis in the Sespe red beds........................................ 55

6. Sketch map showing location of Kentuck group of wells in syncline

in Sespe red beds................................................ 57

7. Sketch map of Foot-of-the-Hills oil wells............................. 59

8. Sketch map showing location of the Fourfork group of wells, with relation to the base of the upper purple beds.......................... 60

9. Sketch map showing location of the Fortuna wells, with relation to the

anticlinal axis...................................'. ................ 70

10. Section through Fryers Peak east of Fryer's ranch.................... 92

11. Sketch map showing location of Placerita Canyon wells, 5 miles east

of Newhall....................................................... 100

12. Generalized geologic section for the immediate vicinity of the Los

Angeles oil fields................................................. 144

13. North-south section across the central field........................... 171

14. North-south section along Hoover street, Los Angeles.................. 175

15. Detail of section along line C-D, western oil field.................... 178

16. Detail of section along line A-B, western oil field.................... 181

17. Northwest-southeast sections in Salt Lake field........................ 189
PREFACE.

Soon after Mr. Eldridge's lamented death, June 29, 1905, an examination was made of his unfinished reports on the oil fields of California to determine in what shape he left them. His field work had 

covered a period of approximately one year, from about July 1, 1901, 

to July 1, 1902. During this time he had examined all the principal 

oil districts from San Mateo County southward to the Santa Ana 

Mountains. He had planned to describe the oil fields of this entire 

area in one large monograph, and at the time of his death had practically completed the manuscript and accompanying geologic maps for 

the chapters on the Parkfield (Monterey County), Santa Clara Valley 

(Ventura and Los Angeles counties), and Puente Hills (Los Angeles 

and Orange counties) districts. Poor health for some time previous 

to his death precluded his doing more than this; and although there 

were copious notes relating to all the other districts none of these 

had been written up. The sad duty of preparing the nearly completed manuscript for publication and of utilizing the remaining 

notes for other reports was assigned to the writer.

In order to facilitate the publication of the chapters nearest completion it was deemed expedient to issue them one or more at a 

time as bulletins, instead of in a single monograph, as originally contemplated by Mr. Eldridge. This change in the method of publication necessitated some changes in the arrangement of the text and 

the treatment of the subject. In making these alterations, however, 

it has been the writer's sincere effort to modify as little as possible 

Mr. Eldridge's style of writing and manner of presentation.

The text and geologic maps of the Santa Clara Valley and Puente 

Hills reports are entirely the work of Mr. Eldridge, with the exception of some changes in the arrangement and some minor additions, 

bringing them up to date. The choice and preparation of the illustrations and the preparation of the cross sections fell to the lot of 

'the writer. The forbearance of the reader is besought for any 

inconsistencies or deficiencies in this bulletin, as they are doubtless 

largely due to the writer's inability to interpret and transcribe the 

ideas which Mr. Eldridge recorded in his notes.

RALPH ARNOLD.

JUNE 30, 1906.

THE SANTA CLARA VALLEY OIL DISTRICT, 

SOUTHERN CALIFORNIA.

By GEORGE HOMANS ELDRIDGE.

INTRODUCTION.

This paper presents a brief description of the oil fields of the region 

adjacent to the Santa Clara Valley, in Ventura and Los Angeles 

counties, Cal. Owing to the somewhat limited time available for the 

field work it has been impossible to go into as much detail concerning certain of the fields as might be desirable. However, it is hoped 

that the data here brought together will be of assistance in the 

future development of the district. Figures of the characteristic or 

common fossils of the different formations of the district are given 

in Pis. XXV to XLI. The physical and chemical properties of the 

oil are treated on pages 203-218.

ACKNOWLEDGMENTS.

The writer wishes to extend- his sincere thanks and acknowledgments to the officers and operators of the different oil companies in 

the district for their hearty cooperation and support. Without the 

data furnished by them the preparation of such a report as this 

would have been impossible.

TOPOGRAPHY.

The Santa Clara Valley of southern California is a structural 

depression modified by erosion. The heads of the valley lie in the 

San Gabriel Range and in the mountains to the north, which connect this range with other portions of the Coast Range and with 

the Sierras. After a westerly course of 75 miles the stream which 

drains the valley enters the Pacific a little south of the town of 

Ventura. The valley proper is given over to agriculture, but in 

the mountains on either side are many important oil fields.

The mountains north of the valley form the watershed between 

it and the Central Valley of California and also present a barrier to 

the Mohave Desert, which lies in the angle between the Sierras 

and the more southerly ranges of the State. These mountains are
OIL DISTRICTS OF SOUTHERN CALIFORNIA.

excessively rugged and represent the convergence of several ranges, 

which to the northwest maintain a conspicuous individuality. Pine 

Mountain, which is 7,488 feet in altitude, is their culminating point. 

The area thus occupied forms a part of the Santa Barbara Forest 

Reserve, recently set aside by the United States Government. The 

greater portion of it is accessible only by trail and is almost wholly 

uninhabited.

Oil-producing regions covered by 

geologic maps in this report

Other principal oil-producing 

regions of the State

COALINGA DISTRICT

McKITTRICK 

MIDWAY 

SUNSET 

SANTA CLARA 

SANTA MARIA 

BAKERSHELD

LOS ANGELES 

PUENTE HILLS 

SUMMERLAND

FIG. 1. Index map of a portion of southern California, showing the location of the three districts 

described in this bulletin and of the other important producing districts of the State.

The San Gabriel Range, in which rise the southerly heads of Santa 

Clara River, equals in ruggedness and general altitude the mountains to the north. ' This range, with its western extension, the 

Santa Susana Mountains, separates the Santa Clara Valley from 

those of Los Angeles, Tujunga, and San Gabriel rivers, while still 

farther west Oak Ridge and South Mountain, in extension of the
U. S. GEOLOGICAL SURVEY

, 1. PANORAMA ACROSS HOPPER CANYON TO VALLEY OF PIRU RIVER. 

From Hopper Peak Ventura County.

B. THE GREAT TOPATOPA ANTICLINE, SESPE OIL FIELD. 

From hill above Los Angelas wells, Ventura County.
SANTA CLARA VALLEY: TOPOGRAPHY. 3

Santa Susana Mountains, lie between this valley and the minor 

depression of the Simi. The San Gabriel Range attains its maximum altitude at 10,080 feet in San Antonio Peak, in the eastern 

portion of the uplift. The highest peak in the Santa Susana Mountains reaches 3,756 feet. Oak Ridge and South Mountain rise to 

maximum elevations of 3,000 and 2,258 feet, respectively.

The Santa Clara receives its principal streams from the north. 

Named from east to west, these are: Castac, Piru, Sespe, and Santa 

Paula creeks. The courses of these streams are most tortuous, their 

loci having been determined in part by structure, in part by erosion. 

Their can37~ons are deep, sharply cut, and in many places cliff bound 

and inaccessible. In addition, there is a well-distributed and dense 

growth of chaparral. Sespe and Santa Paula creeks carry comparatively large amounts of water throughout their length. Piru Creek 

is a somewhat smaller stream, but is sufficient for the irrigation of 

the fertile lands which border its lower course to a width of a mile 

or more on either side. The Castac Valley is practically dry.

The Ojai Valley, an intermontane depression which evidently had 

its origin in a system of profound faults, but whose aspect has since 

been modified by erosion of the strata over the area of excessive disturbance, lies some distance north of the lower part of the Santa Clara 

Valley, yet from a geologic standpoint it is a part of the general area 

here considered. The trend of the valley is east and west; its length 

is about 12 miles, and its width from 2 to 3 miles. The drainage 

is now chiefly to the west, San Antonio Creek. flowing through it 

and joining Ventura River, a stream of considerable size, which 

flows thence 10 miles to the south, entering the Pacific at the town of 

Ventura, not far from the mouth of the Santa Clara. At the eastern 

edge of Ojai Valley; however, a minimum of the drainage passes into 

Sisar Creek, which discharges into Santa Paula Creek. Midway of its 

length a low ridge divides the depression into two parts, known as the 

upper and lower valleys. The altitude of the upper valley ranges 

from 1,250 feet at its western extremity to 1,500 feet at its eastern; 

that of the lower valley from 750 to 1,000 feet. Ojai Valley is well 

watered from natural streams and wells. A few miles up Matilija 

Creek are noted hot springs that are reported to have remarkable 

healing powers.

North of Ojai Valley is the Topatopa Range, 7,000 feet in altitude; 

on the south is Sulphur Mountain, 2,750 feet. The mountainous 

country north of the valley can be reached only by trails, and although 

the distance across it to the San Joaquin Valley is but 36 miles, the 

region is one of the least accessible in the United States. Sulphur 

Mountain presents a steep northern face little indented with canyons; 

its southern slope, however, has been severely scarred by erosion, but 

is traversed by canyon roads. (See PL II.)
4 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

The centers of settlement in the Santa Clara Valley include Ventura, Santa Paula, Fillmore, Piru, Newhall, Camulos, and Saugus, 

their relative importance being in the order named.

The oil fields north of the Santa Clara Valley are developed on the 

open slopes in front of Mount San Cayetano and in the tributary canyons to a distance into the range of 5 to 10 miles. These fields 

include in succession from east to west, Piru, Modelo, Nigger, Hopper, Tar, Little and Big Sespe canyons, and the San Cayetano, Silver 

Thread, arid Ojai fields. They follow in their development the line of 

the higher mountains. From Santa Paula Canyon westward, however, there is a line of wells in Adams, Salt Marsh, Wheeler, and Aliso 

canyons, along the south side of Sulphur Mountain, in strata younger 

than those carrying most of the wells in the fields just referred to. 

Prospecting is carried on west of Aliso Canyon, even as far as the 

valley of Ventura River, but no productive territory has yet been 

found in that area.

The productive wells south of the Santa Clara Valley are confined 

to the northern slopes of the Santa Susana Mountains and Oak Ridge, 

with the exception of a single well in the canyon of Placerita Creek, a 

stream which drains a portion of the northwestern slope of the San 

Gabriel Range. The field in which this well lies is the easternmost 

of those developed. Next westward is the Elsmere field, a mile or two 

southeast of Newhall; to the southwest of Newhall, in canyons descending from the Santa Susana Mountains, are, successively, the 

Rice, Wiley, Towsley, Dewitt, and Pico fields, the last noted in the 

past, as well as at present, for the lightness of its oil and the magnitude of its production. Along the northern face of Oak Ridge, 5 or 

6 miles west of the Pico- field, are those lying in Tapo, Eureka, and 

Torrey canyons; Wiley, Garberson, Shields, Grimes, and other canyons have also been prospected, but without much,success, except 

in the case of Grimes Canyon, west of which no developments have 

thus far taken place.

The railway connection for these oil fields is the Coast division of 

the Southern Pacific, which unites with the San Joaquin Valley 

division at Saugus and passes thence southward to Los Angeles, distant 33 miles.

GEOLOGIC FORMATIONS.*

GENERAL STATEMENT.

The formations of the Santa Clara Valley include certain Pleistocene beds of which the precise horizon is not determined; a great 

series of conglomerates, sandstones, and arenaceous clays which were 

designated by Hamlin some years since as the Fernando formation

a See p. 143 for table of tentative correlations between the oil-bearing formations of southern California.
SANTA CLAEA VALLEY: TOPATOPA FORMATION. 5

and which probably .represent all of the Pliocene and overlap into 

both the Miocene and the Pleistocene; the Modelo formation, of san,dstones and shales, which may prove to be the homologue of the 

Monterey; the Vaqueros formation, of shales, interbedded limestones, 

and sandstones; the Sespe formation, in the main a great.body of 

brownish-red sandstones and conglomerates; the Topatopa formation, of quartzites, sandstones, and hard, more or less siliceous, and 

earthy shales; and an older.basement of gneisses and granites, probably of Jurassic age. This series of formations appears to be conformable from the base of the Topatopa as far up as the base of the 

Fernando, where a distinct chronologic break is observable-. The 

later Pleistocene, also, is unconformable with the beds below, resting 

here upon one formation, there upon another.

GRANITIC BASEMENT. 

GENERAL CHARACTER AND DISTRIBUTION.

The oldest rocks in the territory under discussion are the gneisses 

and granites which underlie the Tertiary sediments east of Newhall. 

The gneisses are close grained, micaceous, conspicuously banded, and 

greatly contorted. In the region mentioned they strike approximately 

N, 70° W. and dip 50°-SO° N. The underlying granitic rocks are mostly 

medium to fine-grained diorites, similar to those lying farther east 

which make up a large part of the San Gabriel Range. These and the 

other crystalline rocks found in the San Gabriels have been described 

by Arnold and Strong.0 The granitic rocks are probably contemporaneous with those of the Sierra Nevada, which are of late Jurassic age. 

The most remarkable thing in connection with the gneisses east of 

Newhall is the occurrence in them of a very light oil, approaching a 

naphtha. Alternative hypotheses regarding the origin of this oil are 

given in the discussion of the geology of the Elsmere field (pp. 100-101).

TOPATOPA FORMATION. 

GENERAL CHARACTER.

The Topatopa formation receives its designation from the name of 

the range of which it is the chief constituent. It is the lowest formation outcropping in the mountains north of the Santa Clara Valley. 

Its total thickness is unknown, but about 5,500 feet are exposed. 

This consists of excessively hard, submassive sandstones arid quartzites, the latter of a greenish-gray color, clear or mottled with white, 

and shales, which differ from the quartzites in carrying an additional 

content of mica, in the fineness of their material, and consequently in

o Arnold, Ralph, and Strong, A.M., Some crystalline rocks of the San Gabriel Mountains, California: 

Bull. Geol. Soc. America, vol. 16,1905, pp. 183-204.

Bull. 309 07 -2
6 OIL DISTEICTS OF SOUTHERN CALIFOBNIA.

their structure. The shales are of a slightly bluish hue, but discolor 

a rusty brown from the presence of iron or petroleum, or both. The 

mottlings of the quartzites, which are very characteristic, are usually 

about one-fourth inch in diameter, round or irregular in outline, and 

in many instances are as conspicuous as the greener, more homogeneous portion of the rock. The sandstones of the formation are usually 

' light gray to white, and are only a little less hard and close textured 

than the quartzites. They carry numbers of Ostrea, the shells of 

which are usually black and 4 or 5 inches long by 3 or 4 inches across. 

It is difficult to obtain good specimens of these fossils, and their determinative value remains for the present unknown.

The quartzites and sandstones greatly predominate in the lower 

2,000 feet of the formation as exposed, and the shales in the upper 

portion, but both types of rock intermingle to a considerable degree, 

imparting thus to the series as a whole a marked uniformity of appearance, which, with the persistency of its principal characteristics, is of 

especial value in identification. The formation contains toward the 

middle quartzites similar to those lower down.

The conspicuous features of this formation are a tendency to a broad 

concretionary structure in some of its members; the presence of 

smaller brown ferruginous sand concretions; the sparse distribution 

of fossil oysters and other very imperfect molluscan remains through 

-a great portion of its thickness, more particularly in the shales; 

some evidences of woody tissue, and a frequent recurrence of what 

appear to be fucoids.

The upper part of the Topatopa formation pn the lower slopes of 

the mountains on the north of the Ojai Valley consists of a succession of very ferruginous rusty-brown and gray sandstone and sandy 

shale, perhaps 2,500 feet thick in all. This facies of the Topatopa 

extends eastward as far as the Silver Thread field, adjoining the 

Ojai Valley on the east. The dip of the rusty beds at the mouth of 

Senor Canyon is southward, changing to northward at a point 

immediately within the low outer hills of the range. West of the 

canyon the northerly dip is maintained to a point far up the slopes. 

East of the canyon there are a number of flexures of greater or less 

severity, but of short extent. The strata are also bent at this point, 

the strike, which east of Sulphur Canyon is N. 60° to 70° W., west of 

the gorge becomes east and west, or even a little south of west, this 

direction being maintained to a point beyond Matilija Creek.

Cross-bedding is here and there observable. In the shaly zones there 

is a remarkable tendency to rapid variation in the thickness of the 

component layers; there also appears to be a certain amount of intraformational unconformity.
SANTA CLAEA VALLEY: SESPE FORMATION. 7 

DISTRIBUTION.

The Topatopa formation occupies the heart of one of the greatest 

anticlines of southern California. The eastern limit of the formation 

is the eastern wall of Sespe Canyon. . Westward it extends to a point 

far beyond the Ojai Valley indeed, beyond Santa Barbara, a distance 

of at least 50 or 60 miles. Besides the area thus occupied there is possibly a small inlier in the heart of the Coldwater anticline (see p. 8), 

although the distance beneath the lower members of the Sespe formation is but slight. San Cayetano Mountain is also composed of this 

formation.

AGE.

Characteristic Eocene fossils have been obtained from the upper 

part of the Topatopa formation in the region north of the Silver 

Thread field. With the exception of the granite and gneisses previously described, no rocks older than the Topatopa are exposed in 

the Santa Clara district.

OCCURRENCE OF OIL.

The Topatopa formation is oil bearing at several horizons, and from 

it come seepages and sulphur springs. While these have been observed 

more particularly from the upper portion, they are also reported from 

the lowest beds exposed at the heart of the anticline.

SESPE FORMATION. 

GENERAL CHARACTER.

The term Sespe has been employed a to designate a prominent and 

widely distributed mass of brownish-red sandstones and conglomerates, with minor layers of sandy and muddy shales, in all about 3,500 

feet thick. With these are included 400 or 500 feet of white sandstone and greenish shale at the base and an equal amount of rust-colored calcareous sandstone at the top. The entire formation is exposed 

in a continuous section in the gorge of Sespe Creek near the entrance 

of Tar Creek and in the region which extends eastward between the 

waters of Tar and Little Sespe creeks. Throughout the formation the 

materials, whether fine or in the form of pebbles, are chiefly granitic. 

The coloring of the beds is in the main due to iron, but the pink feldspar adds to the effect.

o Waits, W. L., Cull. California State Mining Bureau, No. 11, 1897, pp. 25-20.
8 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

LOWER ZONE.

Fig. 2 is a section of the lower 400 feet, which forms a persistent 

divisional zone between the Topatopa formation and the main mass 

of red beds. This part of the formation occurs at the mouth of a small 

tributary entering Sespe Creek from the slopes of Sulphur Peak at a 

point about a mile above the mouth of Tar Creek. It reappears 2 or 

3 miles lower down Sespe Creek, in the heart of the Coldwater anticline. The distinguishing features of this zone are the whiteness of 

its sandstones, in contrast with the measures both above and below, 

and the delicate green and pink tints which pervade its clays and

FIG. 2. East-west section across Sespe Canyon above mouth of Tar Creek, showing detail of the 

lower portion of the Sespe formation, together with its oil-bearing sands.

shales. The heaviest of the sandstones is a, bed about 80 feet thick 

at the base. The lower half of the zone has produced oil in commercial quantities.

RED BEDS.

GENERAL DESCRIPTION.

The beds of brownish-red color which constitute the mass of the 

Sespe formation and overlie the lower zone present at their base a 

band of coarse conglomerate from 40 to 100 feet thick. Above this is 

300 or 400 feet of massive sandstone, with pebbles here and there. 

This is overlain by approximately 500 feet of heavy sandstone, with
. . SANTA CLARA VALLEY: SESPE FORMATION. 9

thin bodies of shale. The material of this sandstone is in many places 

coarse and gritty. Still higher are from 400 to 800 feet of sandstone 

and shale, the latter being somewhat more prominent than lower down 

in the formation. While the conglomerate is principally developed 

as indicated, layers of comparatively coarse pebbles are not infrequently encountered from the base to the summit of the red beds. 

There are, however, great masses of sandstone of uniform texture and 

cOlor, capable, it may be remarked incidentally, of yielding a building 

stone of high grade. These beds as here described maintain their 

principal characteristics of color, texture, and composition wherever 

encountered in the Topatopa Range and its subordinate ridges. 

They occur in the type locality of the formation and form a conspicuous feature along the northern edge of the Ojai Valley and farther 

west, in the vicinity of Summerland and Santa Barbara.

FIG. 3. North-south section on north side of Lower Ojai Valley, showing lithologic variation in strata.

KED BEDS IN THE OJAI VALLEY.

The Sespe formation or what is believed .to be its stratigraphic 

equivalent in the Ojai Valley consists of conglomerates, sandstones, 

and shales, bright red and white, the former color largely predominating. The red beds are not so unbroken, however, as in Sespe Canyon. 

On the contrary they are interrupted not only by certain white sandstones, but also by very considerable bodies of rusty sediments, which 

in some instances suggest a transition to the formation that is possibly 

the equivalent of the Topatopa. This lithologic variation is illustrated in the accompanying profile (fig. 3), which is taken from the 

lower slopes of the range bordering the Lower Ojai Valley on the north. 

The shales of the formation are not conspicuous, except in the region
10 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

of Lion Canyon, where a thickness of between 50 and 100 feet in a 

single body is attained, the colors being rusty, gray, red, blue, and 

black.

RED BEDS SOUTH OF THE SANTA CLARA.

Certain evidence, which is as yet inconclusive, leads to the belief that 

south of Santa Clara River the Sespe formation is represented by a 

succession of gray and red-banded sandstones and coarse arenaceous 

clays that are conspicuous along the lower slopes of Oak Ridge. The 

- rocks correspond in composition to those of Sespe Canyon. The red 

color is similar in both localities, and the overlying formation in both 

instances bears lower Miocene fossils. In the heart of the anticline 

which passes along the front of Oak Ridge a short distance above its 

base the Sespe consists of a massive rusty-yellow sandstone, bearing 

layers of small- granitic pebbles. j The sandstone in fresh fractures is 

locally brown, apparently from having once been impregnated with 

petroleum. Immediately overlying it are from 150 to 400 feet of 

banded bright-red and gray sandstones, argillaceous sands, and arenaceous clays. The transition is in some instances gradual, in others 

sharp and pronounced. The red and gray beds are also repeated 

beneath the rusty-yellow sandstone first described, as is evidenced in 

the wells of the Bardsdale Crude Oil Company, sunk adjacent to the 

axis of the anticline, a mile west of Grimes Canyon. Both red and 

gray beds are locally conglomeratic, the pebbles comprising clear 

quartz, red and blue quartzites, granite, chert, eruptives, and metamorphic rocks of several varieties. Small bodies of white limestone 

also occur here and there, interbedded in the formation.

OIL IN THE RED BEDS.

North of the Santa Clara oil has been produced in considerable 

quantity at a number of horizons in the red beds, and south of the 

river, in at least one locality, the suggested homologues have also 

yielded some oil.

UPPER ZONE.

Immediately overlying the body of red beds is about 500 feet of 

ferruginous, greenish-gray calcareous sandstone, in layers 8 to 10 feet 

thick, separated by thin bands of shale. Certain beds of the sandstone are so calcareous as to be almost sandy limestones. These are 

fossiliferous in many places, although no well-preserved forms were 

obtained. Oysters appear to predominate. The zone of sandstone 

thus defined is best seen in the ridge dividing Little Sespe Creek and 

its tributary, Fourfork Creek, from Tar Creek, and in the valley of the 

latter, where it appears as a conspicuous parting between the red beds 

below and the great series of Vaqueros shales above.
SANTA CLAKA VALLEY: SESPE FOEMATION. 11

RELATION OP UPPER SESPE BEDS TO VAQUEROS SHALE.

No sharp lines of distinction separate the upper Sespe terrane from 

the underlying red beds or the overlying Vaqueros. On the contrary, 

there is a perceptible tendency for the terranes to shade one into 

another. Fossils of value have not yet been collected from .this transitional zone. There is, therefore, some uncertainty as to whether 

the beds in question should be referred to the Eocene or the Miocene. 

The red beds proper are commonly regarded as of Eocene age. In 

Sespe Canyon fragments of grayish-yellow sandstone, coming either 

from some horizon unrecognized but well .up in the red beds or. from 

a horizon corresponding to that of the rusty beds just described, have 

been found bearing well-marked Eocene fossils, among which are the 

forms Venericardia 'planicostcb Lamarck (PL XXV, fig. 1) and Turritella uvasana Conrad (PL XLI, figs. 2 and 3). Beds of a similar 

nature, with an abundance of Tejon (Eocene) fossils, also occur along 

the northern edge of the Silver Thread oil field, ^west of Santa Paula 

Canyon, overlying certain pink and gray sandstones that are believed, 

on lithologic grounds, to belong to the Sespe. The following species 

have been found at this locality. With one exception they were identified by the late J. G. Cooper.a

(Eocene) fossils from north side of Sisar Greek, west of Santa Paida Creek.

Pecten calkinsi Arnold. 

Pecten interradiatus Gabb. 

Solen parallelus Gabb. 

Spirocrypta pileurn Gabb. 

Tellina hoffmaniana Gabb. 

Tellina longa Gabb. 

Tellina parilis Gabb. 

Thracia seniiplanata Whiteaves. 

Turbonilla n. sp. 

Yoldia arata Whiteaves. 

Yoldia nasuta Gabb.

Anatina sp.

Cardium linteum Conrad.

Corbula n. sp.

Dentalium cooperi Gabb.

Leda gabbi Conrad.

Leda n. sp.

Meretrix calif orniana Conrad.

Nassa cretacea Gabb.

Nesera dolabriformis Gab]?.

Nucula truncata Gabb.

Nucula solitaria Gabb.

It may be, therefore, that the rocks in question represent the uppermost member of the Eocene in the region of the Santa Clara and the 

mountains to the north. On the other hand, the resemblance of several of the beds of this transitional zone to others a little higher in 

horizon, that bear identified Oligocene or lower Miocene forms, is to 

be borne in mind. To determine satisfactorily the limits not only of 

this, but of all the other formations in the Santa Clara district, a large 

amount of field work will be required. The difficulty will be enhanced, 

too, by the highly disturbed condition of the rocks and the complicated structural relations which they bear one to another, unless 

distinctly characteristic fossils are found to correlate the beds of the

» Bull. California State Mining Bureau No. 11,1897, pp. 84-85.
12 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

several localities. Tentatively, however, the line between the Sespe 

(Eocene) and the Vaqueros (lower Miocene) formations -has been 

drawn at an indefinite horizon in the rusty beds described, at a point 

where the sandstone no longer predominates but is largely replaced 

by shale, yet below the lowermost lower Miocene fossils found.

OIL IN THE UPPER SESPE BEDS.

It is probable that a portion of the oil yielded by the Fourfork and 

Tar Creek wells has been drawn from the rusty series at the summit 

of the red beds or else from similar thinner beds in the lower part of 

the Vaqueros formation. It will be observed that the entire series 

of beds designated the Sespe shows a remarkable distribution of 

petroleum, in both its vertical and horizontal extent.

VAQUEROS FORMATION. 

AGE AND GENERAL CHARACTER.

The formation designated Vaqueros, appears to be largely lower 

Miocene. The position.of 3,000 feet of shale, such as make up the 

Vaqueros, below beds which are certainly well down in the Miocene, 

suggests the possibility that the lower part of the shale extends into 

the Oligocene. By a rough estimate the maximum thickness of the 

Vaqueros formation is between 2,000 and 3,000 feet, but the amount 

of sediment deposited evidently varied greatly from point to point. 

From the base upward the following more or less distinct zones are 

recognizable: Shales, purplish, rusty, and gray in color, purplish prevailing, perhaps 500 feet; a conspicuous zone of gray shale, 500 feet; 

a series of deep maroon, brown, and gray shales, approximately 

700 feet; and an upper body of siliceous shale and limestone, gray, 

but weathering a pronounced yellow, 500 or 600 feet. The formation 

is therefore distinctly one of shale from top jbo bottom. Throughout its extent lenticular limestones occur, with a tendency to form 

continuous bands a foot or two thick. Much of the shale also is 

calcareous. ,

Through the lower half of the basal purplish zone are threaded 

thin layers of calcareous grits or gritty limestones. Where the quartz 

ingredient is sufficient, they resemble certain beds in the underlying 

rusty zone at the top of the Sespe formation. These beds are fossiliferous, and from them were gathered the following representative 

forms, determined by Ralph Arnold:

Fossils from Vaqueros formation.

. TAR CREEK, BY TRAIL SIDE. 

Modiolus sp.

Ostrea cf. idriaensis Gabb.

Pecten sespeensis Arnold (PI. XXXIII, figs. 1, la, 2). 

Turritella ineziana Conrad var. sespeensis Arnold (PI. XLI, fig. 6).
SANTA CLAKA VALLEY: VAQTJEROS FOBMATION. 13 

IN TRIBUTARY ENTERING LITTLE SESPE CREEK AT FOOT-OF-THE-HILL WELLS.

Balanus concavus'Bronn. (PI. XXXII, figs. 5, 5a).

Pecten sespeensis var. hydei Arnold (PI. XXXI, fig. 2).

Placunanomia sp. \ . Scutella fairbanksi Merriam (PI. XXIX, fig. 3; PI. XXX, fig. 3).

LITTLE SESPE CREEK, BELOW FOOT-OF-THE-HILL WELLS.

Balanus concavus Bronn. (PI. XXXII, figs. 5, 5a).

Pecten sespeensis Arnold (type locality) (PI. XXXIII, figs. 1, 'Ja, 2).

Trophon n. sp. (large).

Turritella ineziana Conrad var. sespeensis Arnold (PI. XLI, fig. 6).

The limestones bearing these fossils are conspicuous in their persistency. One or another appears at intervals for several miles 

along the Tar Creek trail; again on upper Fourfork Creek, half a 

mile west of the upper wells; on Little Sespe Creek below the Footof-the-Hill wells; and in a tributary that enters Little Sespe Creek in 

the vicinity of the Foot-of-the-Hill wells. Besides the foregoing 

fossils, both shale and limestone, from base to summit of the formation, afford an abundance of foraminifera and fish integuments. 

The Vacjueros thus exhibits a degree of lithologic and paleontologic 

resemblance to the shale of the overlying Modelo formation. The 

stratigraphic position and unique fauna, however, determine the age 

of: these beds, and the sharp line between them and the Modelo sandstones above indicates that the division between the two formations 

should be located at that plane.

About 30 feet below the contact of the gray and overlying maroon 

shale is a very persistent band of gray sandstone from 10 to 40 feet 

thick, the outcrop of which may be readily seen about the extensive 

amphitheater drained by Tar Creek.

The upper series, of calcareous and siliceous shales, is strikingly 

similar in appearance to the Modelo of adjacent localities; moreover, 

they abound in foraminiferal forms. Were the Modelo sandstone to 

disappear and the shales of the Vaqueros and upper Modelo to be 

brought in contact it would be impossible to distinguish a break of 

importance in the entire succession. It is suspected, indeed, that 

this has happened in the western face of Oat Mountain and' in the 

ridge running southward, although with a thinning of the series as a 

whole.

VAQUEROS BEDS IN THE OJAI VALLEY.

The Vaqueros formation in the Ojai Valley is composed of rustcolored conglomerate, sandstone, and shale, together with interlaminated limestone. The conglomerates carry pebbles up to 2 

inches in diameter of black chert, white quartzite, gray granite, and 

purple, green, and maroon eruptives. In places, also, there are 

pebbles that possibly may have been derived from some outcrop of
14 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

the Franciscan formation not far distant. The matrix of the conglomerate is composed of the same materials as the pebbles.

The sandstone bears a striking resemblance to that in the lower 

portion of the Vaqueros formation in the vicinity of Tar Creek, without, however, the strong development that it has there.

The shale is argillaceous, fissile, and primarily of a blue-gray color, 

but this is modified to such an extent by the presence of iron that 

weathered surfaces and hill slopes are prevailingly rusty. Here and 

there faint tinges of red, pink, purple, and green are to be observed, 

shades that characterize the formation in the Tar Creek and Fourf ork 

region.

The limestone beds of the formation vary from a few inches to 6 

feet in thickness. They carry a large proportion of quartzose material and commonly show the presence of comminuted to more or less 

perfect oysters. Locally, also, they are found rich in other remains, 

notably pectens, turritellas, and barnacles, all of enormous size.

The following list of fossils, collected by the writer and identified 

by Ralph Arnold, indicates the general character of the fauna in these 

beds:

Fossils from the Vaqueros formation of the Ojai Valley.

SOUTH FORK AT HEAD OF LOWER VALLEY, ONE-FOURTH OF A MILE ABOVE OLD

REFINERY.

Cliione temblorensis Anderson (PL XXX, fig. 1).

Mytilus mathewsonii Gabb var. expansus Arnold (PI. XXX, fig. 2).

Neverita sp. indet.

Pecten magnolia Conrad (PI. XXVIII, fig. 1).

Pecten vaughani Arnold (Pl/XXXIII, figs. 3, 3o). '

Tritonium, three sp.

Trophon n. sp. (large).

Tumtella ineziana Conrad (PI. XLI, fig. 5).

EAST END OF CREST OF RIDGE BETWEEN UPPER AND LOWER VALLEYS.

Balanus sp.

Chione sp.

Dentalium sp.

Leda sp.

Nassa sp. ^

Ostrea sp.

Pecten crassicardo Conrad (PI. XXXI, fig. 1). -

Pecten lompocensis Arnold (PL XXIX, fig. 1).

Phacoides sp. (flat).

Tritonium or Fusus sp.

Tumtella cf. ineziana Conrad (young).

The precise area of outcrop of the supposed Vaqueros beds in the 

Ojai Valley has not been defined,' but one of the principal exposures, 

which afforded the fossils above enumerated, occurs along Refinery 

Gulch on the south side of the upper portion of the Lower Ojai Valley. 

A second exposure is that in the locality of the section illustrated in
SANTA CLARA VALLEY: VAQUEROS FORMATION. 15

fig. 3. The lithologic features of this section indicate the correlation 

of the red and white sandstones with the Sespe red beds and of the 

overlying fossiliferous rusty beds with the Vaqueros formation, the 

heavy body of rusty sandstones occurring at the base of the Vaqueros 

in the Tar Creek.locality being possibly a variable factor from one 

point to another.

VAQUEROS FORMATION SOUTH OF THE SANTA CLARA.

South of the Santa Clara, along South Mountain, Oak Ridge, and 

the Santa Susana Mountains, is a body of shale, sandstone, conglomerate, and limestone, identified by their fossils with the Vaqueros, 

but at variance with that formation north of the Santa Clara in 

the accession of conglomerate arid in the relative proportions of the 

other sediments. Sandstone, for instance, is far more abundant in 

the formation south of the Santa Clara than north of it. Moreover, 

the thickness of the beds is greatly reduced south of the river, a minimum of 400 or 500 feet appearing in Oak Ridge and South Mountain, 

increasing to about 1,000 feet in the Santa Susana Mountains.

The formation south of the Santa Clara, in its simplest form, consists of 300 or 400 feet of banded chocolate and gray argillaceous and 

arenaceous shales, sandstones, scattered limestone concretions, and 

more or less persistent mollusca-bearing calcareous grits, similar to 

the fossiliferous Vaqueros formation of the Tar Creek amphitheater. 

As a rule 50 to 100 feet of massive, coarse gray to yellow sandstone, also yielding lower Miocene remains, separate the formation 

from the red and gray banded beds below, and another very similar 

bed, 40 or 50 feet thick, carrying fossils of the same age, marks the 

summit of the terrane. This upper sandstone divides the underlying 

shale from 200 or 300 feet of other shale that is more siliceous and 

chalky and nearer the Monterey type.

Locally the shale of the Vaqueros formation south of the Santa 

Clara, in addition to its chocolate and gray colors, assumes faint green, 

blue, and red hues. Thin layers of white limestone appear here and 

there, some of which is highly crystalline, with almost the aspect of 

marble. The sandstone, particularly in the eastern half of the field, 

where it is better developed, carries spherical concretions resembling 

those of the lower Modelo stratum north of the Santa Clara. Besides 

the molluscaii remains, casts and imprints of foraminifera are common 

in the calcareous and siliceous members from base to summit of the 

formation. Toward its top a yellow color is to be observed at many 

places, pervading alike both shale and sandstone.

The foregoing description of the Vaqueros south of Santa Clara 

River is more particularly applicable to that portion of the formation which lies west of Garberson Canyon. East of this region considerable modification occurs. In Wile}'" Canyon, for instance, the
16 OIL DISTEICTS O.F SOUTHEBN CALIFOBNIA.

heavy sandstone that forms so conspicuous a feature immediately 

above the red and gray banded beds at the foot of the main range 

is doubtless the local representative not only of the sandstone bed 

farther west, but also of a considerable proportion of the chocolate 

and gray banded sands and clays that overlie that bed. The change 

in the composition of the beds is gradual and can be readily followed. 

The correlation of the sandstone is finally established by the presence of fossils. It carries pebbles of granitic and other debris up to 

4 inches in diameter and concretions which, as already mentioned, 

closely resemble those of the lower Modelo sandstone north of the 

Santa Glara. The full thickness of the bed at Wiley Canyon can 

hardly be less than 600 feet and is perhaps even in excess of this. 

It is overlain by 100 or 200 feet of gray and brown arenaceous 

shales and sands, a remnant of the beds that are so characteristic 

of the formation farther west, and these are succeeded by approximately 200 feet of thin-bedded yellow sand and 100 feet of brown, 

gray, and white shale, which constitutes the uppermost member of 

the formation. The total thickness between the red and gray 

banded sandstone and shale of possible Eocene age and the siliceous 

shale of Monterey type capping the crest of the mountain is probably not less than 1,000 feet.

The beds cut by Tapo Canyon are broadly separable into the 

same formations as elsewhere in the Santa Susana Mountains, but 

their defining lines are more or less indistinct, and in some places 

it is not certain to which of the two principal formations the 

strata should be referred. There appears to be conformabllity, not 

to suggest transition, between the Miocene and Pliocene series at 

this point, although unconformability is the rule over the Coast 

Range territory. The younger series is, however, marked by conglomerates, while the older is more shaly and its sandstones are 

more thinly bedded. Here and there the older sandstones are concretionary. The shales are brown or chocolate colored, show a siliceous tendency, and increase in proportion to the sandstones as 

depth in the series is gained. In the ridge between the middle and 

east forks of Tapo Greek fully 400 or 500 feet of shale, with a minimum of sandstone, underlies the higher, more sandy members. Both 

shale and sandstone are locally bituminous, arid from them come 

several oil seepages of importance. In this series the wells of Tapo 

Canyon have been sunk. The foregoing description of the older 

succession of strata in these canyons suggests correlation with the 

banded sands and chocolate-colored shale of Torrey and Wiley canyons and even in part with the Modelo north of the Santa Clara, 

though no fossils have been observed in either group of beds. In 

Tapo Canyon there is not less than 2,000 feet of the formation 

exposed, in Wiley Canyon the thickness is less than 1,000 feet, and 

farther west it is barely 500 feet.
SANTA CLABA VALLEY: MODELO FOBMATION. 17

Iii the region of Pico Canyon and to the southeast the beds 

mapped as Vaqueros consist of a great mass of thin-bedded shale 

overlain by brown shale, with some more or less important sandstone layers. Above these occur conglomerate, sandstone, and arenaceous clay, which are believed to belong to the Fernando formation, and are so mapped, although no sharp line of demarcation was 

discovered between the two formations.

The following fossils have been obtained from beds mapped as 

Vaqueros in the region south of Santa Clara River. Owing to the 

limited number of species represented the correlations are necessarily very broad. The identifications are by Ralph Arnold.

Fossils from Vaqueros formation south of Santa Clam River. 

ELKIN'S RANCH, OAK RIDGE, EAST OF GRIMES CANYON.

Ostrea eldridgei Arnold (PL XXIX, figs. 2, 2a). 

Turritella ineziana Conrad var. (PI. XLI, fig. 4).

GULCH EAST OF WILEY CANYON.

Pecten (Hinnites) giganteus Gray (PI. XXXII, fig. 1). 

Turritella ineziana Conrad var. (PL XLI, fig. 4).

CHAFFEE CANYON. 

Cardium n. sp. 

Dosinia n. sp.

Ostrea sp. aff. titan Conrad. 

Panopea generosa Gould var. 

Phacoides sp'. 

Acnuea or Trochita sp. 

Turritella cf. ineziana Conrad.

.;

TORREY CANYON AND VICINITY.

Scutella fairbanksi Merriam (PL XXIX, fig. 3, and PL XXX, tig. 3). Mytilus matliewsonii Gabb var. expansus Arnold (PL XXX, fig. 2). 

Ostrea sp. aff. titan Conrad. 

Pecten sespeensis var. hydei Arnold (PL XXXI, fig. 2).

MODELO FORMATION. 

GENERAL CHARACTER.

The Modelo formation embraces at least two prominent bodies of 

sandstone and two of shale. The shale at many points bears a 

marked resemblance to that of the Monterey (middle Miocene), both 

from a lithologic and a paleontologic standpoint, and it may be that 

it is the correlative of that formation. The Modelo is distributed 

over a broad area north of the Santa Clara Valley and through folding 

and faulting its members are brought into most complex relationships. However, it is believed that the distinctions given below 

will serve as a satisfactory means of differentiation.
18 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

LOWER SANDSTONE.

The lowest member, a massive, heavy-bedded sandstone, rests 

directly and apparently conformably upon the Vaqueros shale. It 

varies in thickness from 200 or 300 feet to perhaps 1,500 or 2,000 

feet. It is white to yellowish gray in color. Localty the sandstone 

is gritty, bearing also a dark-gray to black chert, and a few pebbles 

of another sandstone. It contains spherical and elliptical concretions from 1 foot to 5 feet in diameter, which are so prominent and 

so resistant to weathering as to form a conspicuous characteristic of 

the member, the more so because of the utter lack of such concretionary bodies in a second, otherwise similar sandstone that occurs 

higher up. The upper half of the sandstone is less concretionary 

than the lower and is also thinner bedded, the layers being separated 

by shale of a dark-drab color, which carry scattered gray limestone 

concretions that weather yellow. Traces of organic life are also 

visible. This member is usually stained dark with petroleum.

This lower sandstone early received the name Modelo, but the 

writer has thought it best to assign the name t.entatively to the entire 

formation described in the opening lines of this section. The sandstone is best displayed in the bold escarpment east of Tar Creek and 

is also heavily developed in Hopper Canyon and at the head of 

Modelo Canyon. A large number of productive wells have been 

drilled in Modelo Canyon, the oil being doubtless derived from some 

of the lower horizons of the formation. Plate II, A, gives an idea of 

the appearance of this sandstone in the region north of the Modelo 

wells.

UPPER SANDSTONE.

The upper sandstone of the Modelo formation is but little less conspicuous than the lower, although its maximum thickness has been 

estimated at only 900 feet and in many places it is even less. It has 

the same mineral constitution as Qthe lower bed, being composed of 

white, subangular quartz, with a trace of the salts of iron, which 

have colored it slightly yellowish. A considerable amount of dark 

chert is also present, and in one locality beautiful green and brown 

pebbles of siliceous shale were observed. The member is, however, 

nonconcretionary. It is also thinner bedded than the lower sandstone and for 100 feet at the base is not only comparatively micaceous, 

but is split by minor bodies of shale, the whole somewhat darker than 

the portion overlying, seemingly from the presence of dried petroleum. 

This portion weathers a peculiar bluish gray.

This sandstone is conspicuously developed in the region of Hopper 

Canyon, where it lies in a well-marked syncline that to the east is 

sharply compressed and, perhaps, faulted. South of this syncline the 

sandstone is involved in one or two other folds and finally, between 

Hopper and Nigger canyons, passes beneath the Santa Clara Valley.
SANTA CLAHA VALLEY: MODELO FOKMATION. 19 

SHALE IN THE MODELO.

The two sandstones described above are divided by a body of earthy 

shale, gray to brown, which bears limestone concretions weathering 

yellow and whose thickness has been variously estimated at 400 to 

1,600 feet. Overlying the upper sandstone is a second body of shale, 

of uncertain thickness owing to the fact that in the region under discussion not only has erosion removed the sediments down to an undetermined horizon in the formation, but an unconformity also exists 

between this and the overlying formation. However, the thickness is. 

variously estimated at between 200 and 1,500 feet, according to 

locality. This shale is indistinguishable from that separating the two 

Modelo sandstones already described. Both vary from a granular, 

siliceous type to one of an earthy and fissile character, more readily 

breaking down under the influence of weathering. The color of the 

lower bed is commonly light gray; that of the upper may be brown, 

gray, or yellowish. Both bodies carry calcareous layers and here and 

there lenticular limestone concretions that weather yellow. Were 

the upper sandstone to disappear the shales above and below would 

become a single mass, uniform in their general features, from top to 

bottom; were both sandstones to disappear it would be difficult to distinguish these rocks from the upper portion of the Vaqueros formation. 

They would be -more readily differentiated from the lower portion of 

the Vaqueros, however, by the variety of color in the older beds and 

by the marked change to the rusty, calcereo-arenaceous grit at their 

base.

' VARIATION IN COMPOSITION OF THE MODELO.

The foregoing paragraphs describe what appears tt) be the normal 

section of the Modelo formation, but the aspect varies somewhat from 

point to point, by reason of the subdivision of the sandstones and the 

changes in their relative porportion to the formation as a whole. At 

the head of Modelo Canyon, for instance, the outcropping portion of 

the lower sandstone appears to be split into two bodies, each 300 feet 

thick, by 60 to 100 feet of shale, and a similar division is shown by 

the logs of wells drilled in this canyon. What may prove to be the 

upper sandstone is separated from the lower by only about 200 feet 

of brown shale as compared with 400 to 1,600 feet in the normal section. The enormous development of the Modelo sandstones in the 

lofty divide separating Tar Creek from the drainage of Hopper Canyon 

and Pirn Creek is also at variance with the average thickness of either 

of these members, and it may be that the shales are reduced to a 

minimum in this locality, resulting in a sandstone facies for this 

formation amounting to at least 2,000 feet. ~ /

South of Santa Clara River the Modelo formation is unrecognized, 

nor is it possible to find for it a proved correlative. Certain sandstones assigned here to the Vaqueros terrane carry concretions that
20 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

closely resemble those in the lower Modelo sandstone, and the associated shale is also very much like the shales of the Modelo series 

north of the river. Yet these beds south of the Santa Clara contain 

fossils similar in a measure to those of the lower members of the Vaqueros in the Tar Creek, Little Sespe, and adjacent districts. This, 

with the diminished thickness south of the river, suggests a rapid and 

marked variation in conditions during the sedimentation of these 

mportant formations in the §anta Clara Valley.

All the shales of the Modelo formation, as well as those of the Vaqueros, carry at one horizon or another minute foraminiferal remainsand fish integuments, similar in general appearance to those commonly present in the Monterey shale in other portions of California.

Many of the layers in the Miocene shales, whether older or younger, 

are necked with particles of dried bitumen, indicating a general distribution of petroleum throughout the shales and suggesting that it 

may have been derived from the abundant organic life once present 

in them.

The lower Modelo sandstone also bears considerable bitumen in the 

region of Modelo Canyon, and it is said that in summer it yields numerous seepages of a comparatively light petroleum.

SUPPOSED MODELO BEDS IN THE OJAI VALLEY AND SULPHUR MOUNTAIN.

The supposed equivalent of the Modelo in the Ojai Valley and Sulphur Mountain is confined to beds similar to those which characterize 

the upper portion of the formation in the type locality; that is, it consists of shale, siliceous, chalky, or earthy, in color white, gray, or 

locally maroon, carrying the customary limestone concretions and interbedded here and there with sandstone of fine grain and a thickness up 

to 10 or 15 feet. In the shale are found the usual foraminiferal remains, 

abundant pieces of fish integument, and, it is reported, even bony fish 

skeletons. The soil formed by the disintegration of the formation is 

black. The extreme silicification that is so common a feature of the 

shale immediately at and below a mountain crest in other localities 

is repeated in Sulphur Mountain. The thickness of the formation in 

the region under discussion seems to be at least 1,500 feet.

CORRELATION OF THE UPPER SHALY PORTION OF THE MODELO WITH 

THE MONTEREY SHALE.

/

In the Santa Clara district the presence of the Monterey formation 

is uncertain, although the uppermost shale of the Modelo north of the 

river and the great mass of siliceous shale and "chalk rock" that so 

conspicuously caps the Santa Susana Mountains, Oak Ridge, and 

South Mountain, south of the river, may be a part of it. Only one
SANTA CLAKA VALLEY: MODELO FORMATION. 21

fossil, the cast of a thin flat pecten, closely resembling Pecten pedroanus 

Trask (PI. XXXVI, figs. 5, 6), has so far been found in these shales; 

this .was obtained in the outcrop immediately east of the road in Sulphur Canyon, southwest of Bardsdale. This evidence, however, supports the suspected correlation, which otherwise is based on lithologic 

resemblances only. It might be well to say, furthermore, that the 

type locality of Pecten peckhami Gabb (PL XXXI, fig. 3) is the Ojai 

Valley (probably in the shale on the south side) and that this species 

is unusually abundant in the Monterey shale in most regions where 

the formation is known.

DIFFICULTIES OF CORRELATION BETWEEN NORTH AND SOUTH SIDES OF 

SANTA CLARA VALLEY.

The division of the great series of beds north of the Santa Clara into the 

Vaqueros and Modelo is made easy by the abrupt and marked change in 

the character of the sediments at the contact of the lower Modelo 

sandstone and the underlying shale. South of the river this division 

does not appear to hold, yet one or another of the characteristics of 

the Miocene, taken as a whole, north of the river reappears on the 

south side, suggesting that the beds on both sides of the valley from 

base to summit should be included in a single formation. The difficulty of correlation south of the river is greatly increased by the presence of sharp folds and faults. For example, in the normal succession 

the siliceous shale and the "chalk rock" unquestionably overlie 

beds of altogether different character, identified as the Vaqueros; yet 

at the east end of Oak Ridge and in the western portion of the 

Santa Susana Mountains an equally heavy body of siliceous shale 

appears to dip beneath similar shale that is believed to be of lower 

Miocene age. This unusual succession may be attributable to faulting, the siliceous shale being the younger. On the other hand, it 

may possibly be that the siliceous shale capping Oak Ridge corresponds 

to the mass of siliceous shale that occurs as the uppermost of the 

Vaqueros beds in their type locality. In this" case the Modelo would 

be entirely wanting south of the river.

Another element in the difficulty of correlating the formations on 

opposite sides of Santa Clara River is the remarkable decrease in 

thickness toward the south. It would seem that the formations 

referred to have their type and maximum development north of the 

Santa Clara, and that south of the river the formations are thin, either 

through lack of material or through rapid changes in the attitude of 

the land, which resulted in intervals of nondeposition or even of erosion during the time the beds were being laid down.

Bull. 309 07 3
22 OIL DISTRICTS OF SOUTHERN CALIFORNIA. 

BURNING OF THE SHALE.

The siliceous shale and " chalk rock" forming the crest of the mountains south of the Santa Clara have at many points been burned to a 

bright-red color. The fuel which supported such fires was perhaps 

the originally contained petroleum.

Opposed to this view, however, is the very .considerable depth to 

which the shale has been altered to a brilliant-red lava-like rock; hence 

it may be inferred that spontaneous combustion alone has brought 

about the modification.

FERNANDO FORMATION. 

GENERAL CHARACTER AND AGE.

The rocks that have received the name Fernando 0 consist, of an 

enormous succession of conglomerates, sandstones, and arenaceous 

clays, largely of Pliocene age, developed over considerable portions of 

southern California. Fossils collected at many localities and at many 

horizons throughout the formation indicate that it extends from the 

upper Miocene (San Pablo formation of the general geologic column 

of the State) well up in the Pleistocene (San Pedro formation). It 

is possible to subdivide the formation locally on both lithologic and 

paleontologic grounds, but taken over a considerable extent of territory these divisions merge into one another both stratigraphically and 

geographically by insensible gradations. An unconformity usually 

marks both the base and the top of the formation, although in several 

localities in the Santa Clara region that at the base is difficult if not 

impossible to detect.

Along the sides of the Santa Susana Mountains and Oak Ridge and 

in the region east of Newhall the coarser beds of this formation are 

usually white, gray, or yellow, the clays bluish gray. The material 

of the conglomerate is principally granitic, but pebbles of the intermediate formations are occasionally found. In the limited region 

under survey no established succession of the different sediments was 

observed, although a broader field would doubtless reveal it. The 

unconformities are always to be reckoned with, and to them may be 

due in large measure the variations in the rocks that are in contact. 

Incidentally it may be observed that perhaps to them also may be 

due the fact that whereas south of the general fold out of which the 

several ranges are formed the Fernando is usually in contact with 

siliceous shale, north of the anticline, on the slopes of the Santa Susana 

Mountains, it is found resting directly upon beds that are of the 

Vaqueros facies.

o A term applied in unpublished maps by Homer Hamlin a number of years ago to the beds above the 

siliceous shale skirting the sides of the San Fernando Valley, Los Angeles County the general equivalents of all the post-Modelo, pre-Saugus beds in the Santa Clara province.
SANTA CLAEA VALLEY: FERNANDO FORMATION. 23

In the vicinity of the Piru Valley the Fernando formation consists 

in ascending order of (1) a thick body of sandstone and conglomerate; 

(2) sandy shale and clay; and (3) heavy-bedded coarse conglomerate. 

These form the northern slope of the ridge north of Camulos, the distance of about 4,000 feet being equally divided among them. Overlying the upper conglomerate are several hundred feet of greenish-gray 

clay, and it is believed that this is succeeded in turn by 1,500 to 2,000 

feet of alternating sandstone and conglomerate. If the succession is 

continued, clays then follow to the valley of the Santa Clara. In all, 

the" formation is fully 5,000 or 6,000 feet thick in this vicinity, and if 

its thickness could be determined over the entire area that amount 

would doubtless be increased by many thousands of feet. The materials of the conglomerates include granite,.shale derived from the 

Miocene, and a few eruptives.

North of the Santa Glara Valley, extending from the mouth of Sespe 

Canyon westward to the Pacific Ocean at Ventura, is another extensive area of the Fernando. The formation is best developed in the 

hills between Santa Clara River and Sulphur Mountain, where the 

succession consists of sandstones and conglomerates, underlain by a 

thick body of clay dirt-brown to gray in color. This clay is arenaceous and grades into sandstone both transverse to the strata and along 

the strike. In places even pebbly layers may be found in this part of 

the formation. Beneath the clay is another mass of heavy-bedded 

sandstone and conglomerate, separated by minor layers of clay, 

resembling that just described. If there are not faults in these beds 

and none were detected the thickness can hardly be less than 8,000 

or 10,000 feet, about equally divided between the three varieties of 

sediments mentioned. Some of the lower sands are bituminous and 

their associated clays are brown or blue.

On the lower slopes of San Cayetanp Mountain, making up a part of 

the area outlined in the preceding paragraph, is a mass of gray clay and 

shale, sandstone, and heavy gravel beds, all more or less hardened 

and resistant to weathering, which belong to the upper Fernando. 

The pebbles making up the gravel deposits are granite, quartsite, sandstone, limestone, and the harder shale all derived from the mountains of the Sespe region.

PALEONTOLOGY OF THE FERNANDO FORMATION.

At least three distinct faunas are recognizable in the Fernando, 

representing what are thought to be in a very general way the bottom, 

middle, and top of the formation. The oldest fauna was found in the 

area north and northeast of Camulos, and is, according to J. C. Merriam, the equivalent of the fauna of at least a part of the San Pablo 

formation. The middle fauna was found well developed in the region 

of Elsmere Canyon and Fernando Pass, and probably represents the
24 OIL DISTKICTS OF SOUTHERN CALIFORNIA.

typical fossiliferous portion of the Purisima and the lower part of the 

San Diego formation. The upper portion of the Fernando extends 

well up into the Pleistocene, as is attested by the fossils found at Barlow's ranch and on the south slopes of Mount San Gayetano; these 

have been correlated with the fauna contained in the San Pedro formation.

LOWEK FERNANDO FAUNA.

The following species have been found in what is supposed to,be 

the oldest portion of the Fernando, in the region north of Gamulos: 0

Fossils from the lower part of the Fernando formation, near Camulos.

[Those marked "a" are from the light-colored shale underlying the conglomerate on Santa Felicia 

Creek; " b," from conglomerate 5 miles northeast of Camulos;' 'c," from fine conglomerate and coarse 

sandstone 1 mile north of Camulos; "d," from coarse conglomerate 1 mile north of Camulos; "e," 

from conglomerate on the east side of Piru Creek, near the railroad bridge.]

Area camuloensis Osmont (b, d) (PL XXXVII, figs. 1, la, Ib).

Bulloid n. sp. (c).

Callista subdiaphana Carpenter (c) (PI. XXXIX, fig. 3).

Cancellaria n. sp. (b).

Cardium sp. (b).

Chlorostoma sp. (c).

Chrysodomns n. sp. (1) (b).

Chrysodomus n. sp. (2) (c, d).

Conus californicus Hinds (b, e).

Conus cast, sp. indet. (c). '

Corbula n. sp. (c). . Dosinia ponderosa Gray? (e).

Echinarachnius, near excentricus Eschscholtz (a).

Fusus rugosus Trask (d).

Leda taphria Ball (b, c) (PL XXXVIII, fig. 5).

Lunatia lewisii Gould (c, d).

Macoma, near secta Conrad (a).

Macoma secta Conrad (b).

Mangilia sp., probably new (c).

Metis alta Conrad? (d).

Nassa californiana Conrad (b).

Nucula castrensis Hinds (d).

Nucula n. sp. (c, d).

Ostrea veatchii Gabb (d) (PL XXXIX, fig. ].). . Pachypoma n. sp. (a, b).

Pecteh bellus Conrad (e) (PL XXXV, fig. 3).

Pecten cerrosensis Gabb (c, d) (PL XXXV, fig. 6).

Pecten merriami Arnold (a) (PL XXXVI, fig. 9).

Priene oregonensis Redfield var. angelensis Arnold (PL XL, fig. 11)

Phacoides sp., probably new (b).

Solen sicarius Gould (a).

Turritella n. sp. (b).

Yoldia scissurata Dall (c).

o Collected by W. L. Watts; identified by J. C. Merriam; listed in Bull. California State Mining 

Bureau No. 19,1900, pp. 220-222.
, SANTA CLARA VALLEY : FERNANDO FORMATION. 25 

MIDDLE FERNANDO FAUNA.

The following species, found in Elsmere Canyon and the region of 

Fernando Pass, apparently represent a somewhat later fauna than 

that just described. The identifications are by Ralph Arnold.

Fossils from the middle of the Fernando formation, Elsmere Canyon.

Amiantis callosa Conrad (PI. XXXIX, fig. 2).

Area trilineata Conrad (PI. XXXVIII, figs. 3, 4).

Callista subdiaphana Carpenter (PI. XXXIX, fig. 3).

Cancellaria fernand6ensis Arnold (PL XL, fig. 4).

Cardinal quadrigenarium Conrad var. fernandoensis Arnold (PL XXXVIII,

fig. 2).

Chione n. sp. (small). 

Chrysodomus arnoldi Rivers. 

Cryptomya californica Conrad. 

Cyprsea fernandoensis Arnold (PL XL, fig. 8).. 

Dolichotoma cf. carpenteriana Gabb. 

Macoma indentata Carpenter. 

Macoma sp.

Mactra cf. hemphilli Ball. 

Modiolus rectus Conrad. 

Monia macroschisma Dall. 

Murex eldridgei Arnold (PL XL, fig. 12). 

Mya truncata Linne". 

Neptunea liuuierosa Gabb. 

Neverita recluziana Petit (PL XXXVIII, fig. 6). 

Olivella intorta Carpenter. 

Panopea generosa Gould.

Pecten cf. caurinus Gould (PL XXXVI, fig. 1). 

PeQten estrellanus Conrad var. catalinse Arnold. 

Pecten healey'i Arnold, .17 rib. var. (PL XXXIV, fig. 1). 

Pecten cf. parmeleei Dall (PL XXXVI, fig. 7). 

Phacoides acutilineatns Conrad.

Pisania fortis Carpenter var. angulata Arnold (PL XL, figs. 0 and 7). 

Priene oregonensis Reclfield, var. angelensis Arnold (PL XL, fig. 11). 

Tapes tenerriraa Carpenter.. 

Tellina idse Dall (?). 

Tritonium sp.

Trochita filosa Gabb (PL XL, figs. 2, 2a). 

Turritella cooperi Carpenter, var. fernandoensis Arnold (PL XLI, fig. 13).

UPPER FE.RNANDO FAUNA.

Lists of species from three localities are given to show the characteristics of the fauna of the upper portion of the Fernando. The 

fossils in the first list may possibly be slightly older than those in 

the second, which in turn appear to be a little older than those in 

the third. The species from Barlow's ranch have been correlated 

with the fauna contained in the upper fossiliferous beds at San 

Pedro, which are well up in the Pleistocene.
26 OIL DISTBICTS OF SOUTHERN CALIFORNIA.

Fossils from the upper part of the Fernando formation. 

NORTHWEST OF SANTA PAULA."

[Those followed by an "E" are from Goat Mountain, near the mouth of Adams Canyon; those followed by an " F" are from Santa Paula Creek, between Mupa schoolhouse and Sulphur Mountain.]

Astrodapsis whitneyi Conrad (F). 

Astyris richthofeni Gabb (E). 

Bittium aspersurn Gabb (E). 

Cardium corbis Conrad (E). 

Cardium procerurn Sowerby (F). 

Chione mathewsoni Gabb (F). 

Chione whitneyi Gabb (F).

Chorus belcheri Hinds (F). &' 

Clidiopliora punctata Conrad (E). 

Crepidula princeps Conrad (E). 

Cryptomya californica Conrad (E). 

Dentaliurn semipolitum Broderip (F). 

Ecninarachnius excentricus Eschscholtz (F). 

Galerus inornatus Gabb (F). 

Glycyineris intermedia Broderip (F). 

Hipponyx cranioides Carpenter (F). 

Lacuna solidula Loven (E). 

Lsevicardiuin centinlosuni Carpenter (F). 

Lunatia lewisii Gould (E). 

Macoma'n. sp. (F). 

Metis alta Conrad (E). 

Mitra maura Swainson (E). 

Modiolus rectus Conrad (E). 

Monoceros lugubre Sowerby (F). 

Murex monoceros Sowerby (F). 

Nassa californiana Conrad (E). 

 Nassa perpinguis Hinds (E). 

Nassa mendica var. cooperi Forbes (F). 

Neptunea altispira Gabb (E). 

Olivella intorta Carpenter (E). 

Panopea generosa Gould (E). 

Psephis tantilla' Gould (E). 

Semele n. sp. (E). 

Solen rosaceus Carpenter'(E, F). 

Siliquaria edentula Gabb (F). 

Spisula planulata Conrad (E). 

Tellina ida? Ball (E). 

Tresus nuttalli Conrad (E). 

Triton gibbosus Broderip (E). 

Turritella jewetti Carpenter (E) (PI. XLI, fig. 15). 

1 Turbonilla sp. (F).

SOUTHEASTERN FLANKS OF MOUNT SAN CAYETANO.fr

Area cf. labiata Sowerby. 

Bittium cf. asperum. Gabb. 

Nassa perpinguis Hinds. 

Calliostorna or Margarita sp.

aCollected by W. L. Watts; identified by ,T. G. Cooper; listed in Bull. California State Mining 

Bureau, No. 11, 1897, pp. 81-83. 

& Collected by the writer; identified by Ralph Arnold.
SANTA CLAKA VALLEY: FERNANDO FORMATION. 27

Cardium cf. quadrigenarium Conrad (?).

Crepidula cf. rugosa Nuttall.

Lacuna (?) sp.

Lecla sp.

Macoma sp.

Modiolusf?).

Olivella sp.

Pholadidea cf. penita Conrad.

Psephis cf. lordi Carpenter.

Saxidomus gracilis Gould.

Siliqua patula Dixon ('?).

Tapes staminea Conrad.

Tresus nuttalli Conrad (?).

Turritella cooperi Carpenter (PI. XLI, fig. 14).

Yoldia (?) sp.

 BARLOW'S RANCH, 3 MILES EAST OF VENTURA.o

Acnisea pelta Eschscholtz.

Actseon (Rictaxis) punctocoelata Carpenter.

Angulus buttonL Dall. 

Anornia lampe Gray. 

Balanus concavus Bronn. 

Bittium asperum Gabb. 

Cadulus fusiformis Sharp and Pilsbry. 

Cancellaria tritonidea Gabb. 

Chione succincta Valenciennes. 

Chlorostoma funebrale A. Adams. 

Chorus belcheri Hinds. 

Columbella (Astyris) gausapata Gould. 

Columbella (Astyris) gausapata, var. carinata Hinds. 

Crepidula adunca Sowerby. 

Cryptomya californica Conrad. 

Cylichna alba Brown. 

Dentalium hexagonum Sowerby. 

Donax leevigata Deshayes, 

Drillia hemphilli Stearns. 

Drillia inermis Hinds. 

Drillia inermis var. penicillata Carpenter. 

Echinarachinius excentricus Eschscholtz. 

Eulima inicans Carpenter. 

Eulima hastata Sowerby. 

Lacuna coihpacta Carpenter. 

Littorina scutulata Gould. 

Macoma nasuta Conrad. 

Mactra catillifonnis Conrad. 

- Mangilia angulata Carpenter. 

Modiolus fornicatus Carpenter. 

Monoceros engonatum Conrad. 

Nassa californianum Conrad. 

Nassa fossata Gould. 

Nassa mendica Gould. 

Nassa perpinguis Hinds.

« Arnold, Ralph, The paleontology and stratigraphy of the marine Pliocene and Pleistocene of San 

Pedro, Cal.: Mem. California Acad. Sci., vol. 3, 1902, p. 55^
28 OIL DISTRICTS OF SOUTHERN CALIFORNIA. '

o

Neverita recluziana Petit. 

Neverita recluziana var. alta Dall. 

Odostomia gouldii Carpenter. 

Odostomia nuciformis var. avellana Carpenter.

Odostomia tennis Carpenter. . , 

Olivella biplicata Sowerby. 

 Olivella intorta Carpenter. 

Olivella. pedroana Conrad. 

Pecten latiauritus var. monotirneris Conrad. 

Saxidomus aratus Gould. 

Scala crebricostata Carpenter. 

Scala tincta Carpenter. 

Tapes tenerrima Carpenter.

Terebra simplex Carpenter. . . Tornatina culcitella Gould.

Tornatina harpa Dall. . ® 

Turritella eooperi Carpenter (Pi. XLI, fig. 14). 

Turbonilla laminata Carpenter. 

Turbonilla, four sp. (?). 

Yoldia eooperi Gabb.

PLEISTOCENE DEPOSITS, 

DEPOSITS IN THE VICINITY OF SAUGUS.

The low hills that border the broad, op°en valley of Santa Clara 

River in the vicinity of Saugus are covered by a prominent body of 

gravel, sand, and arenaceous clay, the gravel largely predominating. 

The coarser material is mostly composed of granite, derived, probably, from the San Gabriel Range. Traces of other rocks, however, 

are included with the granite, and the whole is loosely cemented 

together. The beds have a general dip of 2° to 10° toward the center 

of the valley. The thickness of the terrane is undetermined. Above 

the level of the valley perhaps 300 or 400 feet are exposed, but below 

the valley the extent of the formation is not known. These beds 

are probably of fresh-water origin and, though they have yielded no 

fossils whatever, their unconformable position on the Fernando suggests late Pleistocene as the time of their deposition.

DEPOSIT AT MOUTH OF SESPE CANYON.

At one point overlooking Sespe Creek there is a cut bluff showing 

bright-red sediments of apparently the same materials as those just 

described. The deposit was not examined in detail. It may prove 

to be a remnant of the Sespe formation or a portion of the Pleistocene 

that is composed of red material derived from the Sespe.

CONGLOMERATE OF LION CANYON.

- In the vicinity of the Lion Canyon wells is a conglomerate that has 

not hitherto been recognized at any point in the Ojai Valley, nor, 

indeed, elsewhere in the ranges that border the Santa Clara. Its
U. S. GEOLOGICAL SURVEYCHARLES D.WALCQTT, DIRECTOR. BULLETIN N0.309 PL.in

Sea.

Feet Topatopa Mts. "i; 

sooo - YZ

. Sea. l&veL

TOPATOPA LOWER SESPE MIDDLE SESPE LOWER SESPE MIDDLE SESPE UPPER SESPE VAQUEROS FERNANDO RECENT

PLIOCENE' PLEISTOCENE

Sea. TeveL j

B

Santa Paula Rid&e r" 

-*-

Feet

Shale and clay Shale with included limestone Sandstone

H ori /. cmtal s c a] e

2 3

Conglomerate and gravel Concretionary sandstone 

_______4_____________S miles

n

o" location, of sections see PL. I.

GEOLOGIC STRUCTURE SECTIONS ACROSS MT.PDTOS, TEJON, SANTA PAULA, AND CAMULOS QUADRANGLES, SOUTHERN CALIFORNIA
SANTA CLARA VALLEY: STRUCTURE. 29

leading feature is the contained bowlders of sandstpne, differing but 

slightly in composition from the matrix or body of the rock itself. 

It appears only in the limited area between the Sespe and Modelo 

formations. A somewhat similar occurrence is found at the east end 

of the Upper Ojai Valley, where Sisar Creek leads out from it. The 

stratigraphic relations of this rock are uncertain, but its composition 

suggests that it may be the remnant of a Recent formation of bowlder 

 sand which here and there skirts the Upper Ojai Valley, forming 

along its northern side, locally, extensive benches. In the region of 

the Lion Canyon wells the rock is impregnated with bitumen, and 

seepages spring from it. It is penetrated by the wells, but it is 

believed that they derive their oil from the underlying formation.

GENERAL STRUCTURE OF DISTRICT.

INTRODUCTORY STATEMENT.

It has been deemed expedient to divide the discussion of the structure of the region bordering the Santa Clara Valley into two sections. 

The first, embracing a brief exposition of the more important features, is included in the pages immediately following. The second, 

dealing with those details so essential for purposes of practical application, is subdivided, each portion being included in the description 

of the territory to which it refers. It may be well to call the reader's 

attention to the general sections on Pis. Ill and IV. These sections, together with the structural features depicted on the map (PI. I, 

pocket), will doubtless more vividly portray the writer's interpretation of the structure than many chapters of descriptive text.

SANTA CLARA VALLEY.

The structure of the rocks underlying the Santa Clara Valley is perplexing. For several miles below Saugus the great body of younger 

conglomerate, sandstone, and clay of the Fernando formation passes 

diagonally across the bottom lands into the hills on either side, mamtaming a strike of N. 50°-60° W. and a dip of 25°-50° NE. Within 

this area there is no apparent break in the regularity of the stratigraphic succession. From the mouth of Salt Creek westward, however, the hill formations become more and more folded, or even 

faulted, while the continuity of structure between the two sides of the 

valley is interrupted by a broad belt of river gravel. Lithologic similarity of both Miocene and Pliocene.sediments at the several horizons 

adds still further to the difficulties attending a correct interpretation 

of the geologic conditions. The great mass of evidence suggests an 

enormous fault along the valley in the region north of South Mountain, 

the displacement dying out as it passes up the river. Final interpretation of the valley structure has, however, been reserved for a time
30 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

when the general geology of the region shall be the primary object of 

investigation. The strip of enigmatical territory occupied by the 

valley therefore forms an obviously ideal line of division between the 

two more or less structurally distinct areas north and south of it, and 

advantage will be taken of this fact to discuss each of these areas separately.

REGION NORTH OF THE SANTA CLARA.

Of the great mountain system north of the Santa Clara Valley the 

southern member, the Topatopa Range, is alone involved in the 

geology of the developed oil fields. This range is 30 or 40 miles long; 

its trend is east and west; its structure is anticlinal, the axis passing 

a few miles north of the area mapped in Pis. I and V.

In the region of Sespe Creek the axis of the anticline lies beneath the 

crest of the range and is occupied by characteristic quartzites and 

slates to which has been assigned the name Topatopa formation. The 

anticline is symmetrical and is well displayed in the canyon walls. 

About the Topatopa formation bend in succession the Sespe, Vaqueros, Modelo, and Fernando beds, all strongly developed and forming 

conspicuous features of the landscape. Toward the east the point of 

the anticline broadens, the Modelo sandstone outcropping in a wide 

sweep about the axis and the youngest beds covering a still greater 

area in their arch. The west end of this great anticline has not been 

located, the consideration of its east end being sufficient for the purposes of the present report.

The northern side of the anticline is unexplored, and whether the 

prominent ridge of granite lying to the north is produced by f aulting 

or is a part of a separate dynamic system is unknown.

The southern limb of the anticline presents an intricate succession 

of secondary folds and accompanying faults that extend from Ventura 

River and the Ojai Valley beyond Piru Creek. East of Santa Paula 

Creek the strata are strongly bowed to the south. At Sespe Creek the 

curvature is as pronounced in the opposite direction. Immediately 

west of Hopper Canyon the convex side of the bend is again to the 

south, while east of Piru Creek regularity of trend is once more approximately resumed. North and east of the Ojai Valley the south 

limb of the Topatopa anticline is overturned.

An examination of the map makes it obvious that faults are the 

dominant structural feature in the Ojai Valley, at the west end of the 

territory under discussion. No less than five fractures cross the 

region from east to west, divergent in trend from N. 60° W. at the 

north to S. 75° W. at the south. The result has been a succession of 

interfault blocks more or less limited in size, with considerable variation in the strata opposed. The faults originated nearly at a common 

center in the great fracture passing in front of San Cayetano Moun-
U. S. GEOLOGICAL SURVEY 

CHARLES D.WALCOTT, DIRECTOR BULLETIN NO.309 PL. IV

Sea- leve- level. ^ _ Sea., level/

sw

leveL

NE

Sea Level

^ Santa Susana 

* Mountains

.Sea.-level. Sea level

SW NE

M*

Sea

NW

Sea. level.

sw NE

Slvale and clay Sliale with in.cliLd.ed limestone Sandstone Conglomerate and gravel Concretionary sandstone

Horiz on_tal scale 

z 3 > miles

For location, ofse^tiojis see PI. I.

GEOLOGIC STRUCTURE SECTIONS ACROSS CAMULOS, SANTIA SUSANA, AND FERNANDO QUADRANGLES, SOUTHERN" CALIFORNIA
SANTA CLABA VALLEY: STETJCTTJRE. 31

tain. The northernmost fault lies between the rusty Vaqueros beds 

and the Modelo shale. South of this is the second .fracture of the 

system, the block between them being composed of Modelo shale. 

Between 'the second and third faults, the latter passing immediately 

north of Lion Ridge, is 'a narrow block of rusty beds of the Vaqueros type. South of this is a comparatively broad zone of the Sespe 

formation, which in turn is separated from the Modelo shale, constituting Sulphur Mountain, by one of the most extensive faults of the 

region. South of Sulphur Mountain there is a fifth fault, marked by 

a line of seepages and oil wells. The evidence of faulting, however, 

must not be confused with the unconformity which exists between 

the Modelo and the Fernando. The shale of Sulphur Mountain is 

considerably crumpled, at least two marked anticlines (one of which 

is locally overturned) and the intervening syncline being present 

through nearly its whole length. The conglomerate, sand, and shale 

of the Fernando formation, south of their contact with the Modelo 

shale of Sulphur Mountain, maintain a southerly dip with marked 

persistency, at most varied only-by minor and localized flexures.

The structural features west of Santa Paula Creek continue to the 

east for 4 or 5 miles, in front of Santa Paula Ridge and San Cayetano 

Mountain, but the faults terminate one by one or coalesce, until at the 

easterly apex of the region the disappearance of interfault blocks has 

brought the late Tertiaries into contact with the much earlier Topatopa formation, the great San Cayetano fault alone separating them.

In the Sespe district it is to be observed that the formations enter 

the Camulos quadrangle at its northern border from their passage 

around the east end of the axis of the Topatopa anticline, which lies 

between .1 and 2 miles to the north. Within the quadrangle crumpling begins near its northern border at first gentle) then severe. The 

major features resulting from this movement are the Coldwater anticline, southeast of the broad table of red beds, and still farther south 

the syncline, whose eastern extension passes through the summit of 

Oat Mountain. South of the western part of this syncline is the great 

northward-dipping monocline of Topatopa. beds on the north flank of 

Mount San Cayetano. Near the mouth of Sespe Canyon the beds are 

greatly disturbed by the close approach of the San Cayetano fault and 

the syncline just mentioned.

In the region east of Sespe Creek the more important of the subordinate or secondary folds include a partially overturned anticline 

southwest of Hopper Mountain; the Oat Mountain syncline, already 

referred to; an anticline that crosses lower Pole Canyon at its sharp 

turn from south to west, and another anticline a mile farther south. 

Each of these folds is a conspicuous feature of the geology from one or 

another point of view, but the syncline is perhaps the most marked, 

involving, as it does, the strata from the upper Modelo shale to the red
32 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

beds of the Sespe. In addition to these, there are numerous local 

folds and one or two faults, each of which is of almost equal import' 

ance to the features first mentioned.

Both Hopper and Piru canyons, in the lower 10 miles, have been 

developed across the structure at points where the strata are extensively puckered, each canyon lying a little east of the axis of a sharp 

strike flexure. The western of the two axes presents a change in 

trend from N. 65°-70° W. to N. 50°-70° E. The easterly axis shows a 

reverse change from N. 60° E. through east-west to N. 80° W. Locally 

slight departures from the general trend are to be found. For 

instance, the Modelo anticline and the syncline immediately to its 

south have a direction approximately east and west, and a number of 

minor folds between 1 mile and 2 miles in length, particularly conspicuous on the east side of Hopper Canyon, lie diagonally to the general trend of the larger flexures. Between the individual folds of the 

several trends direct continuity has not been established, but there is 

a suggestion of this.in several instances, notably in the Oat Mountain 

syncline, which apparently can be traced from Sespe Creek nearly to 

the Modelo district, and again in the, Lyons anticline, which almost 

certainly passes directly from the Piru Valley to Hopper Canyon. In 

any event, the folds are unquestionably the associated crumples of 

a single affected zone that passes continuously, though with wavy 

trend, from the region of Mount San Cayetano to that of Piru Creek.

PI. Ill, sec. X-Z', illustrates the general occurrence of petroleum in 

the mountains north of the Santa Clara Valley. The section without 

being continuous nevertheless represents in nearly their true succession the formations that occupy this great area and portrays the 

structural features that prevail in most of the productive oil territories. 

The line of the section is laid down on the map (PL I). Besides being 

somewhat irregular it presents two important offsets that were necessary to the generalization of the conditions. One of these offsets 

(x'-y) occurs at Little Sespe Creek and is a mile in length; the other 

(y'-z) embraces the interval between Brush Mountain and Piru Peak, 

a distance of 5 miles. In both intervals, however, the break in the 

stratigraphic succession is reduced to a minimum.

The formations involved include the Topatopaformation; the Sespe 

formation, with its three divisions base, middle, and top; the Vaqueros formation, with its several bands of varicolored clays; the 

Modelo sandstones and their accompanying shales, a portion of which 

at least may correspond to the Monterey, and the Fernando formation, which probably extends from the Miocene through the Pliocene 

and well up into the Pleistocene. Their distribution over the line of 

the section may be gathered from the illustration. There are, however, certain features which it may be well to consider somewhat at
SANTA CLARA VALLEY: STBUCTUEE. ' " 33

length, for the reason that they have a bearing on the occurrence of 

petroleum.

The Topatopa anticline, shown at the left of the section, involves 

rocks of the Topatopa formation, which are proved to be more or less 

petroliferous by the seepages that occur on their outcrops and by the 

actual dissemination of bituminous matter through certain of the 

beds. There are, however, no wells that 'penetrate the formation, and 

its possibilities are as yet unknown. At the base of the Sespe formation there is a layer of white sandstone which, in the gorge of Sespe 

Creek, has been found to yield an excellent supply of low-gravity 

petroleum. The well of the Union Consolidated Oil Company penetrates the strata in this vicinity to a depth of approximately 500 or 600 

feet. The position of this well, on the regular slope of the main Topatopa anticline, is of especial importance from the clew it may afford as 

to the occurrence of oil at this horizon under like conditions in other

localities.

A second feature of importance is the Coldwater anticline. The 

strata on the northern face of this arch are productive, the oil being 

derived from about the same horizon as that of the well just mentioned, 2£ miles 'to the northwest. The longitudinal extent of this 

anticline in an easterly direction was not determined by the writer, 

but in Boulder Creek, a little more than a mile to the east, a somewhat similar fold appears nearly in the line of the Coldwater flexure. 

It may be, however, but an offset of the latter or a mere crumple on its 

flanks. It is indicated in the section and is the locus of the Ivers 

wells. Although conspicuous in the field, when plotted it is of comparative insignificance. The oil found at this point may have.no relation to the minor fold, but, on the-other hand, the fractures resulting 

from such a fold may have afforded a special opportunity for the accumulation of the petroleum.

One of the few occurrences of oil observed in California near the 

axis of a syncline is that seen at the Kentuck wells.,, which are 

located in a hollow of the Sespe red beds hah* a mile north of Little 

Sespe Canyon. The most plausible explanation of this exceptional 

occurrence is that it is due to the effects of the Coldwater anticline, or 

possibly even of the greater Topatopa anticline, the negative effects 

of the local syncline being insufficient to overcome the influence of the 

greater folds.

A short distance south of this depression the red sandstone of the 

Sespe formation dips steeply near the point where the axes of the folds 

exhibit a general change in strike from northeast to southeast. The 

locality is one of marked crushing and its structure is most difficult to 

decipher. The offset of a mile in the section was made here, the 

strata being again taken up in regular succession in the vicinity of the
34 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

Foot-of-the-Hill wells. From this locality to the top of Brush Mountain the series of rocks from the upper members of the red sandstones 

of the Sespe through the rusty beds at their summit and the great 

mass of shale that makes up the Vaqueros formation is unbroken. 

Three oil-bearing horizons have been found within this range one 

either at the summit of the red beds or the base of the rusty member 

of the Sespe; another perhaps in the purple clay of the Vaqueros 

formation, and a third in the upper, earthy, and siliceous portion of 

the Vaqueros, not far below the Modelo sandstone. The wells are to 

be regarded as located on the slope of the general Topatopa anticline, 

for a careful examination of the locality reveals only minor and very 

insignificant crumples in the general sweep of the beds in an easterly, 

northeasterly, and northerly curve about the axis of the main fold.

Brush Mountain is capped by the lower Modelo sandstone and a 

thin band of the overlying siliceous shale. The second offset in the 

general section occurs at this point. On Piru Peak very nearly the 

same formations are encountered, the only difference being a somewhat greater amount of the siliceous shale at the top of the series. 

The lower Modelo sandstone outcrops immediately beneath the shale 

and at the head of Modelo Canyon is affected by the Modelo anticline, 

which is one of the most conspicuous and perfect folds of this character to be found anywhere in the region under discussion. The sandstone here, however, appears to be at least several hundred feet thick 

thicker, indeed, than on Brush Mountain, and yet by no means so 

extensively developed as about the head of Hopper Canyon, farther 

north. The succession of strata on the two sides of the anticline 

varies somewhat, but this is perhaps due to crumpling and faulting. 

The presence of a fault is indicated by the abnormal succession of beds 

encountered in crossing the outcrop of the formation. It is probable 

that at the line of this section the opposing beds for some distance 

from the surface belong to the shale between the upper and lower 

Modelo sandstones, but the exact amount of throw is indeterminable, 

first, because of the uniformity of the shale in appearance; second, 

because of the rapid variation in the thickness of the strata, and third; 

because of the crushing that has taken place adjacent to the fracture.

The Modelo anticline is one of the most productive folds north of the 

Santa Clara Valley. About midway of the folds are the wells of the 

Modelo Oil Company, attaining a maximum depth of about 1,800 feet, 

with oil at 1,400 or 1,500 feet and indications of oil at still greater 

depths below the surface. The wells are wholly in the Modelo sandstone, which in places is so free from shale and so solid as to stand 

without casing. The wells are drilled in strata that dip 60° or more 

-on both sides of the anticline, at distances varying from less than 100 

feet to 600 or 700 feet on each side of the axis. The wells of the Sunset Oil Company in Hopper Canyon, 1J miles to the west, are also on
SANTA CLAEA VALLEY: STETJCTUEE. 35

this fold. They have produced some oil, but have not been operated 

with the same care as the wells of the Modelo Oil Company, and as a 

consequence -much water occurs with the oil.

The Nigger anticline lies a mile and a quarter south of the Modelo 

fold, being separated from it by a syncline and the fault already 

described.-, - The strata involved are the upper Modelo sandstone and 

the shales above and below. The productive wells on this anticline 

are in the easterly tributary of Nigger Canyon, a little south of the axis 

of the fold. They are 500 or 600 feet deep, the oil having been encountered at depths of 65 to 400 feet.

Half a mile south of the Nigger anticline is a sharp change in the 

rocks which represents the contact between the Modelo and the Fernando formations. The younger beds have a northerly dip, which 

represents either an overturn at the plane of unconformity or a fault 

perhaps both, That an unconformity exists between the Fernando

formation and the underlying beds is beypnd doubt, and many strata 

are brought successively into contact on either side of the plane. From 

the point of the ridge separating Nigger Canyon from Piru Creek eastward for several miles beyond this stream there is a marked line of. 

disturbance. A synclinal structure has been suspected, but careful 

examination indicates that this .supposition may have been induced 

by the deceptive relations of the dips'; in reality there is probably an 

anticline, with a very steeply inclined southern limb, which west of 

Piru Creek has possibly been the.locus of a fault. At this point in the 

section, therefore, there may be a fault in proximity to a line of unconformity, much after the order of the unconformity and fault passing 

along the southern border of the Puente Hills from the region of the 

Santa Fe wells westward to Whittier. (Seep. 111.) Doubtless the 

dip of the Fernando strata changes from northerly to southerly 

beneath the valley of the Santa Clara, but exposures along the bottom 

lands are wanting, and the relation of the formations north of the 

river to those south of it can only be conjectured.

REGION SOUTH OF THE SANTA CLARA.

The mountains bordering the Santa Clara Valley on the south 

represent the west end of one of the most important uplifts of southern 

California. The center of uplift, the San Gabriel Range, consists of 

granites and related rocks. Encircling these on the west are -sedimentary beds of Tertiary age, which constitute, in the order named 

from east to west, the lower elevations of the Santa Susana Mountains, Oak Ridge, and South Mountain. The structure of this system of ridges is anticlinal and notwithstanding a degree of continuity 

between the formations north and south of the upper portion of the 

Santa Clara Valley the mountains south of the river preserve, on the 

whole, remarkable independence of structure. In the western half of
36. OIL DISTKICTS OF SOUTHERN CALIFORNIA.

the system the structure is comparatively simple, consisting of a 

main anticlinal fold affected by a few subordinate wrinkles. In the 

eastern portion, however, although the effect of the uplift has been 

the production of a single range crest, there are, nevertheless, three 

distinct folds of a more or less secondary nature, arranged en Echelon 

and slightly diagonal in trend to the course assumed by the general 

ridge system. These folds may be designated the Torrey, "Tapo, and 

Pico. A fourth, en echelon with the others and known as the Elsmere, is in reality the western terminus of the San Gabriel uplift 

itself. Although secondary to the dominant structure these folds 

are well developed and are of especial importance in that they have 

become the loci of several very productive oil fields. There are 

numerous minor crumples and, along the southeastern crest of Oak 

Ridge and the southwestern face of the Santa Susana Mountains, at 

least one fault of considerable throw.

OIL FIELDS 3STORTH OF THE SA1STTA CLARA.

The oil fields north of Santa Clara River involve an area having an 

east-west length of 35 miles and a width of 7 to 15 miles. For convenience of discussion, this area may be divided into the Ojai Valley, 

Sulphur Mountain, Si] fer Thread or Sisar Creek, Santa Paula Ridge, 

Sespe, Pole Canyon, and Hopper-Piru fields. (See PI. V.)

OJAI VALLEY FIELDS. 

LOCATION.

The Ojai Valley fields comprise the region of the upper and lower 

valleys, lying between the Topatopa Range on the north and Sulphur Mountain on the south. Nordhoff, the only town within the 

district, lies about 15 miles north of Ventura, with which it is connected by a spur track of the Southern Pacific Company, and 12 

miles northwest of Santa Paula.

STRUCTURE.

PL III, sec. A-A' indicates in a very general manner the structural 

relations of the several formations exposed in this valley. The 

series of beds north of the Lower Ojai Valley is a part of the great 

overturned south flank of the anticline developed in the Topatopa 

Range. The overturning was accompanied by faulting. The delineation of the faults on the map (PI. I) is highly generalized from the 

evidence afforded .by soil coloring and isolated outcrops. They will 

be described in the order of their occurrence from north to south.

The succession of beds from the base of the Topatopa Range, or 

across Lower Ojai Valley, is perhaps without break. If so, there is an 

upper and a lower series of rusty beds separated by a broad belt,
U.S. GEOLOGICAL SURVEY 

CHARLES D.WALCOTT, DIRECTOR BULLETIN NO.3O9 PL.V

RANCHO SAM FRANCISCO

a: x

0/V 'ON OIL CO. OF CAL\ < ^ -''-,.

Oil wells producing Oil wells not pumping 

or drilling Rice », Canyon 

welts * * East Canyon wells

Compiled from U.S.Geological Survey and California State 

Mining B.ureau maps by W.L.Walker and Ralph Arnold

A.HO£N8 CO.BALT/MORE, MO. TO^V^NSHIP AND SECTION 1VTAP OF THE SANTA CJ^ARA VALLEY AND ADJACENT OIL FIELDS, CALIFORNIA

Scale

Oil vvel! locations largely from original, data, a small number however 

- from California State Mining Bureau publicat.ons

5 miles

19O6
SANTA CLARA VALLEY: OJAI VALLEY FIELDS. 37

between 1,000 and 2,000 feet thick, of red and white sandstones which 

seem to belong to the Sespe formation. Between the southerly belt 

of rusty beds, which are regarded as Vaqueros, and the Modelo shale, 

which constitutes Thompson Ridge, there is unquestionably a fault 

the throw of which can hardly be less than 2,000 feet. The Thompson 

Ridge fracture is more directly in line with the San Cayetano fault to 

the east than any of its associates and it may be responsible for the 

existence of both the Upper and Lower Ojai valleys. To the east it 

passes immediately south of the wells of the Bard and adjacent oil 

.companies. Between the Lower Ojai Valley and Santa Paula Canyon 

the thickness of the red beds is greatly reduced, and to the south the 

rusty beds may almost entirely disappear, for in the Silver Thread district the outcrop of these two strata is less than 300 feet thick. From 

the trend of the formations north of the Lower Ojai and from lithologic similarities, it is inferred that the great development of rusty 

beds north of the Bard and Capital Crude wells is continuous with 

those of the Topatopa formation in the lower slopes of the Topatopa 

Range to the west. At this point these beds have furnished a fair 

collection of fossils, which are regarded as Eocene. In this connection 

it is worthy of notice that at the head of the Lower Ojai Valley the 

rusty beds south of the red beds carry fossils that were, with equal 

certainty, determined as lower Miocene.

The.Modelo shale, forming Thompson Ridge, is severely crumpled 

and is probably an included fragment of siliceous shale. It disappears beneath the wash of the Lower Ojai Valley and has every evidence of wedging out a little west of the Silver Thread district.

South of this interfault block of Modelo there is a narrow band of 

rusty beds, which also wedge out to the east. These beds have every 

appearance of the Vaqueros formation arid carry the same fossils as 

those north of the Modelo block. They border Thompson Ridge on 

the south and pass at once into the Lower Ojai Valley, where they 

disappear beneath the later wash. This block of rusty beds presents 

a variety of dips and strikes, and it is thought, therefore, to be simply an inclined fragment-between the great faults of the region. The 

fracture separating it from the red beds bordering it on the south is 

recognized as passing'the valley road at the head of the gorge between 

the Lower and Upper Ojai basins to the west, following the line of a 

short gulch to its junction with the general valley. It is probable 

that in this direction it has been the northern determinant of Lion 

Ridge. To the east the fault seems to pass in a direction about S. 

80° E., merging finally with one or another of the greater fractures 

of the system..

It is interesting, also, to note the occurrence of a narrow strip of 

rusty beds included in 'the Modelo shale in the easterly portion of the 

crest of Thompson Ridge.

Bull. 309- -07 i
38 OIL DISTKICTS OF SOUTHERN CALIFORNIA.

The red beds of the Sespe formation again become prominent in 

Lion Hill, which lies between the Lower Ojai and Lion Canyon to the 

south. This ridge is an anticline, the trend of its axis curving slightly 

from N. 87° W. at the west end to N. 70° E. at the east. The crown 

of the arch is but gently bowed. The flanks, however, show steeply 

inclined strata. Locally, a slight synclinal flexure appears. To the 

north the red beds pass beneath the wash of the Lower Ojai Valley; 

to the south they are succeeded by the Modelo shale of Sulphur Mountain, the line of division being practically coincident with the stream 

channel in Lion Canyon.

The Sespe formation of Lion Hill is doubtless another interfault 

block, more than ordinarily prominent, in the series that occupies the 

Ojai Valley. The apex of this block probably terminates within a 

mile of the Silver Thread district, the small body of red beds appearing in the latter region belonging to the greater mass of similar beds 

lying on the north side of the Oj ai Valley. The Sespe formation in the 

block under discussion widens and becomes an important formation 

in the western portion of the Lower Ojai west of San Antonio Creek 

and Ventura River. On the north the red beds are in contact with 

the rusty beds in the minor interfault block already described, and, 

to the east of this block, with the projecting portion of the included 

fragment of the Modelo formation. On the south they "are in contact 

with the Modelo shale throughout its whole length to San Antonio 

Creek. The minor interfault block of the Modelo in Thompson Ridge 

being disregarded, this Sespe block would appear to have been pushed 

up with reference to the formations north and south of it, particularly those on the north.

Along Lion Canyon and the south edge of the Upper Ojai Valley 

is another of the greater faults of the district. Like the others, 

however, it terminates near the common center in the vicinity of 

Santa Paula Canyon. Farther west it is probably of considerable 

extent, having been recognized, it is thought, at the canyon of Ventura River several miles below Nordhoff. In any event there is the 

same succession here that is encountered in the Ojai Valley.

Sulphur Mountain from one end to the other is composed of the 

Modelo shale, the strike of which corresponds with the trend of the 

ridge about N. 80° E. The dip is generally to the south. There are, 

however, local crumples of different degrees of importance, as, for instance, a possible anticline, indicated on the map (PL I) as passing along 

the lower slope of the mountain, and a second, the axis of which passes 

a little south of the well of the Langdell, Newmark & Roan Oil Company, a few hundred feet below the summit. Also, it is possible that 

faulting, as well as folding, has taken place within the confines of the 

mountain. Such folds and faults may be accountable for the lines 

of petroleum seepages on both the north and south sides of the ridge.
SANTA CLARA VALLEY: OJAI VALLEY FIELDS. 39

Sulphur Mountain itself is perhaps an interfault block, a possible fracture existing at the line of contact of the Modelo and Fernando formations south of the ridge, although the succession maybe merely one 

of unconformity. The writer is inclined, however, to the view that 

a fault is present. The linear extent of the folds in Sulphur Mountain 

has not been determined. The east end of Sulphur Mountain presents 

.a syncline at its crest, an anticline at its northern base coincident with 

the lower portion of Sisar Creek, and another anticline south of the 

mountain in the vicinity of the Adams Canyon oil wells.

There is an anticline south of the western portion of Sulphur Mountain showing in the road which descends from the summit to the upper 

part of the Canada Larga. In the line of this anticline is a like fold 

at Ventura River, and it is possible that the two are continuous. 

Although the rocks involved in this fold belong mainly to the Modelo 

formation, gray and brown argillaceous shales and heavy sandstone,

probably of the Fernando formation, lie immediately upon its southern flanks and locally may have become affected.

OIL WELLS. °

The oil wells in the Ojai fields comprise those of the Union Oil Company on the Pirie ranch, at the west end of Lion Hill; two in Lion Canyon, about 1| miles southeast of the Pirie wells; a couple drilled by 

Langdell, Newmark & Roan near the summit on the north slope of 

Sulphur Mountain, and a group along the northeastern side of the 

Upper Ojai, sunk by the Whidden-Double, Sobra Vista, and Santa 

Paula oil companies.

PIRIE RANCH WELLS.

Two groups of wells belonging to the Union Oil Company are located 

on the Pirie ranch south and southeast of Nordhoff, in the Lower Ojai 

Valley. The first group, consisting of three wells, is about a mile S. 

25° E. of the town, on the west end of Lion Hill; the second group lies 

across a small valley, about three-fourths of a mile S. 70° W. of the 

first. All the wells penetrate the red beds of the Sespe formation, 

those of the first group being about 100 feet south of the axis of the 

Lion Hill anticline, and those of the second on the south limb of the 

same anticline, at least three-eighths of a mile south of its axis. At the 

time of the writer's visit the wells were abandoned and only one derrick was standing. It was learned, however, that black oil accompanied by considerable quantities of gas was struck in the wells of the 

first group, and that for a time they were pumped. Gas was heard 

rumbling in one of the holes and another contained water. No seepages were noticed in the locality of the wells.

Five wells constitute the second group, four close together and a 

fifth about one-fourth mile to the southwest. The deepest of the four
40 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

is about 1,500 feet deep.. A little oil was encountered at 30 feet and 

some also at about 400 feet; for a time considerable oil and water, 

mostly the latter, were pumped. In another well thick oil was struck 

at 100 feet and a lighter oil at 333 feet, thus indicating at least two 

oil-bearing strata .for this locality. Much water was found in the 

westernmost well and it was abandoned before reaching the oil sands.

LION CANYON WELLS.

Two wells, now abandoned, were sunk in Lion Canyon about 2^ 

miles southeast of Nordhoff. They are situated in the brown shale of 

the Modelo formation, not far south of the fault separating the shale 

from the Sespe red beds of Lion Hill. The wells lie in line with 

what to the east is a faulted overturn, but which here may be only a 

simple anticline. Heavy oil stands in the eastern well at a depth of 

about 200 feet, while a lighter emulsion of oil and water rises to about 

the same level in the western well. Some of the oil which had been 

bailed out and was standing in a barrel had a gravity of about 16° B.. 

It was black and ran quite freely, though stringing some.

LANGDELL, NEWMARK & ROAN AYELLS.

The two abandoned wells of this company are located on the north 

slope of Sulphur Mountain, only a short"distance below its crest and just 

west of the road leading up from the Upper Ojai Valley. The holes 

are sunk a little north of the anticlinal axis, which passes immediately 

north of the summit of the mountain, and penetrate the brown and 

gray shales of the Modelo formation. The higher well is located at the 

upper edge of a prominent oil seepage; it is said that a little light oil was 

struck at about 800 feet and that the well was abandoned in a white 

clayey shale at 1,000 feet. The lower well was sunk right in the seepage, but yielded nothing. The natural seepage 'of oil at the wells is 

claimed to be about a barrel a day.

WHIDDEN-DOUBLE WELLS.

The five wells of the Whidden-Double Oil Company are located in 

the Modelo shale fault block on the northern side of the head of the 

Upper Oj ai Valley. The surface outcrops here show a slight northerly 

dip, while the well logs indicate a much steeper dip to the northeast for 

the oil sand. The structural relations in the vicinity are somewhat 

complex, but it seems likely that the wells are situated on the 

north flank of an- anticline more or less complicated by minor folds. 

It is reported that the holes vary in depth from 132 to about 950 feet 

and that they yield oil of 8° to 15° gravity. The petroleum is black 

and in two of the wells is associated with more or less water. The 

deepest well is said to penetrate two sands, the lower of the two 

yielding the lighter oil. An interesting fact is that No. 3, one of the
SANTA- CLAKA VALLEY: OJAI VALLEY FIELDS. 41

shallower wells, although having a greater initial production than No. 

5, which was deeper, did not hold out nearly so well. The yield of the 

wells was never very great and they were finally abandoned in 1904.

SOBRA VISTA WELM.

The Sobra Vista wells, three in number, are located at the head of 

the Upper Ojai Valley, immediately south of the Whidden-Double 

property. As indicated by the structure in the immediate vicinity, 

the wells are probably located on the north flank of the local anticline 

which is so well developed in the region of the Santa Paula group of

Whidden-Double wells

Santa Peula Oil Co! 

wells

.Ventura 

Oil CoJf 

(well

Srea, and, oil <$ 

I s

i!

4 . Whidden- 

 Double 

wells

FIG. 4. Sketch map showing location of wells and oil seepages in the northeast corner of the Upper 

Ojai Valley. Heavy blackNdots, wells abandoned since beginning of 1902; the other symbol, wells 

abandoned previous to 1902.

wells immediately to the west. The strata penetrated are the blue 

and gray shales of.the Modelo formation, here containing interbedded 

sands from which, it is said, the wells derive their oil. In fact, the 

southernmost well of the group is located precisely on the line of 

strike of the sandstone which affords the heavy oil seepages on the 

Santa Paula property. The wells range in depth from about 375 to 

740 feet and obtain their oil from two sands about 240 feet apart, the 

upper varying from 10 to 11 feet and the lower from 4 to 11 feet in 

thickness. It is said that an 11-foot stratum of black water sand was 

encountered between the oil sands in one of the wells, and that in
42 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

another the drill was stopped in a deposit of tar too heavy to pump. 

The best well is reported to have started with a yield of 50 barrels per 

day, but this was reduced to about 13 barrels at the time of the 

writer's visit (1902), and still later is stated to have fallen off considerably more. The oil is black and heavy and is sai'd to run 48 per cent 

of exceptionally pure (92 per cent) asphaltum.

SANTA PAULA WELLS.

Immediately west of the Sobra Vista group, at the head of- the 

Upper Ojai Valley, are the two wells of the Santa Paula Oil Company. 

They penetrate the blue shale of the Modelo formation, which is here 

folded into a westward-plunging anticline. The wells derive their oil 

from interbedded sandstones, some of which yield seepages of heavy 

asphaltum. The northern well is farther down the dip and is the 

deeper of the two. It is reported that this yielded lighter oil than the 

southern well and that the latter struck oil similar to that encountered 

in one of the Sobra Vista wells, which was too heavy to pump.

SOUTHERN SULPHUR MOUNTAIN FIELD. 

LOCATION.

The oil areas that have been developed along the southern base of 

Sulphur Mountain lie at the heads of Aliso, Wheeler, Salt Marsh, and 

Adams canyons and along the short gulch heading against Adams 

Canyon from the Santa Paula Valley. All are a short distance south 

of N the northern boundary of what once constituted the San Buenaventura Mission. The general elevation of these areas is about 1,100 

feet, Sulphur Mountain rising abruptly above to heights between 

2,500 and 2,750 feet. The canyons are of easy grade and the intervening ridges are comparatively low.

GEOLOGY.

Two and perhaps three formations are involved in this field 

Modelo shales; Fernando conglomerate, sandstone, and clay; and 

possibly certain remnants of the Pleistocene, consisting of coarse 

gravel and gritty sand.

The Modelo is confined to Sulphur Mountain and consists of blue 

and brown, finely laminated shale, which is either earthy or siliceous, 

here and there even slightly sandy, and thin beds of sandstone. The 

shale is the conspicuous feature, however, and is of the type variety. 

It carries the customary gray to yellow limestone concretions, which 

with the shale show an abundance of organic remains, foraminifera 

and fish integuments and their impressions. The browner variety of 

the shale is gypsiferous and carbonaceous.
SANTA CLAEA VALLEY: SOUTHEEN SULPHUE MOUNTAIN. 43

Adjacent to the line of division between this shale and the succeeding formation there is in places a body of earthy shale, the general 

color of which is brown and through which are threaded thin-bedded 

sandstones from a few inches to a few feet in thickness. All in all, 

this shale somewhat resembles others of doubtful age that are encountered in the oil fields of the Santa Susana Mountains and is not unlike 

certain beds that underlie the more siliceous shale of the Modelo formation in the region of Hopper Canyon. The question regarding the 

beds referred to in the Santa Susana Mountains is whether the shale 

actually belongs to the Modelo or to a younger formation, although 

perhaps still of Miocene age. The same uncertainty holds for the 

shale of the Sulphur Mountain localities until detailed work shall have 

determined its proper reference. A possible characteristic that may 

prove to be of value in distinguishing this shale from those of the 

Modelo, the more finely laminated beds of which are of a like brown 

color, is the mud-like texture and consistency of the younger shales. 

The younger clays are, moreover, decidedly arenaceous, and are also 

commonly associated with sandstones.

The formation regarded as Fernando forms the mass of the hills 

between Santa Clara River and Sulphur M'ountain, except, perhaps, a 

Pleistocene fringe along the immediate valley. Some of the lower 

sands are bituminous, this characteristic appearing to become more 

conspicuous as Sulphur Mountain is approached. The clays associated with the lower sands are brown or blue. The conglomerates of 

this series include pebbles of sandstone, quartz, granite, black chert, 

and siliceous shale, the last evidently derived from the Modelo and 

probably from Sulphur Mountain itself. The succession of beds here 

described is encountered also, though with some variation, in the 

Santa Paula Valley and in the several canyons to the west of Adams 

Canyon.

By reason of the uncertainty regarding the age of the brown shale 

referred to above it is evident that the line between the Fernando 

and the Modelo formation is indefinite. It is worthy of note in passing 

that there is a considerable difference in the gravity of the oils derived 

from the Modelo shales and the Fernando sands and gravels in this 

field, that from the Modelo being much the lighter.

Deposits of sand and coarse gravel occurring in the lower portion 

of Adams Canyon are doubtfully referred to the Pleistocene series. 

These have the appearance of being an outlier of the more prominent 

body of like sediments east of the Santa Paula Valley. The deposits 

have, however, received but passing attention and have little or no 

bearing on the geology of the Sulphur Mountain oil district.
44 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

STRUCTURE.

Sees. A-A' and B-B', PI. HI, show the probable structural relations 

of the different formations in the Sulphur Mountain region. The 

relation between the Modelo shale and the succeeding formation along 

the southern base of Sulphur Mountain is primarily that of unconformity, but faults are here and there suggested by the sharp contrast 

of the beds in contact and by the flexures that have particularlyaffected the strata in proximity to the line of the suspected fracture. 

The fault, if it exists, is in harmony with the other structural features 

of the region and is supplemental to those farther north already 

described. It is the southernmost component of the system radiating 

from the San Cayetano fracture a mile or two east of the Santa Paula 

Valley. In each of the canyons in the southern face of Sulphur 

Mountain evidences of the fracture are more or less distinct.

Of the flexures in the area under discussion the sharpest occur in 

the interfault block of the Modelo shale. The most conspicuous one 

occurs halfway up the face of Sulphur Mountain. It consists of a 

zone of severely crushed strata 100 to 200 feet broad.

A short distance south of the suspected fault, in the younger formation of clay, sandstone, and conglomerate that is possibly the 

Fernando, there may be here and there detected an anticlinal fold, its 

axis having the general strike of the formation, varying from N. 65° E. 

at the eastern terminus of the mountain to N. 80° E. farther west. 

The southern limb ef the anticline extends beneath the foothills to 

the Santa Clara Valley, the dip varying from 45° to 80°, but usually 

approaching the lesser angle. The northern limb is steep, short, and 

truncated by the plane of the fault. This structure appears in several 

of the canyons and hill areas, but its continuity from point to point 

has not been established. Instead of an anticline it may be, perhaps, 

but a bending downward of the strata, a crumpling of the beds due to 

compression adj acent to the fracture. In Adams and .Wheeler canyons the anticlinalfeature is somewhat stronger, while in Aliso Canyon 

general crumpling seems to prevail. Farther west, however, in the 

region of Harmon Canyon, the anticline again appears.; the northern 

limb is still short and terminates in a sharp reverse flexure, or perhaps 

at the fault, which marks the junction of a series of table-like benches 

with the main body of the mountain. The entire region north of 

this fault to the Topatopa Range is a succession of displaced blocks, 

crumpled in the manner just described. From the axis of this disturbance southward to the Santa Clara Valley the strata maintain 

their southerly dip with marked persistency, at most varying only by 

minor and localized flexures.
SANTA CLARA VALLEY: SOUTHERN SULPHUR MOUNTAIN. 45 

OIL WELLS.

The line of the suspected fauLt along the south side of Sulphur 

Mountain is marked in the several canyons by many strong seepages 

of petroleum.; and in proximity to the fracture, in the northward dipping or more severely crumpled strata of the Fernando formation, 

most if not all of the wells of this general field are drilled. Those 

yielding the lighter oil, however, may penetrate to minor sands in the 

Modelo, or they may be peculiar to the brown shale of uncertain 

though perhaps Modelo age (p. 19). The heavier oil without doubt 

occurs in the Fernando formation..

The wells in the field under discussion have been drilled at the heads 

of Aliso, Wheeler, Salt Marsh, and Adams canyons and along the bottom of a short gulch east of Adams Canyon. But little new development was under way at the time of the investigation arid it was difficult to obtain data relating to the occurrence of the petroleum. Furthermore, many of the wells were old and were abandoned, while the 

product of others was reduced to only 1 or 2 barrels a day. The initial 

flow of some of the wells appears to have been as high as 25 or even 

50 barrels. The depth as a rule ranges between 150 and 500 feet, but 

here and there 1,800 or 2,000 feet is said to have been attained. An 

early mode of recovering the oil was by tunnels, many of which penetrate the shale of Sulphur Mountain. From these a small amount of 

oil still seeps, although several barrels a day have been obtained.

Two varieties of oil occur in this field one black, with a gravity of 

19° to 30° B.; the other green, with a gravity of 30° to 32° B. The 

lighter oil, as already stated, is believed to be associated with the 

shale doubtfully assigned to the Modelo formation. It occurs nearer 

the base of the mountain than the black and heavy oil. The comparatively shallow depth of certain of the wells yielding green oil and 

their location well up on the slopes of Sulphur Mountain suggest the 

possibility that the productive beds outcrop in the base of the mountain. None of the strata, however, so far as the writer could learn, 

showed any indication of containing petroleum.

The duration or life of the wells varies. Two years seems to be 

the maximum for the larger yields, but. beyond this time the product 

dwindles to 1 or 2 barrels a day and then remains constant for an 

indefinite time. This constancy, coupled with the inexpensiveness of 

pumping, accounts for their still remaining in service.. The earliest 

drilling reported in this field was done by Mr. Adams twenty-five 

years ago in Adams Canyon. This well and another in proximity, 

put down by the Union Oil Company, afforded a light oil, and a similar 

product was obtained by wells in Salt Marsh Canyon. Periodic 

attempts have been made to develop the source from which this supply was derived, but .without success. Opinions differ as to the relations of the light oil to the Modelo shale. It is possible that this oil
46 OIL DISTRICTS OP SOUTHERN" CALIFORNIA.

is derived from the strata adjacent to the shallow wells (about 200 

feet deep) which are probably in the Modelo shale; but on the other 

hand, the beds are severely crushed and the oil may be derived from 

a considerable depth, rising through fissures in the shale. Of the 

wells in Salt Marsh Canyon, one yielding green oil is said to have produced an average of 60 barrels a day after the head had been pumped 

off. It is said also that in the Salt Marsh wells the horizon affording 

green oil is first struck, the black variety being 100 or 200 feet lower 

down. In Wheeler Canyon the conditions are reversed, the top oil 

having a gravity of 28° B. and the lower, 400 or 500 feet below, of 30° B. 

The dip of the strata in the several productive areas of this field 

varies from 45° to 80° N. South of the axis of folding and crumpling 

south of the productive line, therefore the dip is usually less than 

45° S., although here and there 80° may be attained.

SILVER THREAD OR SISAR CREEK FIELD. 

LOCATION.

The Silver Thread field is developed on the high ground immediately north of Sisar Creek, near its confluence with Santa Paula Creek, 

directly opposite the productive territory east of the latter stream. 

PL VI, B, shows its position in relation to the surrounding country.

STRUCTURE.

The field is included within the area of the great fault system extending from San Cayetano Mountain to the Ojai, and is therefore in structural relationship with the producing fields both west and east of it. 

It lies within a short distance of the point of convergence of the several faults.that form so conspicuous a feature in" the geology of this 

region. PL III, sec. B-B', indicates the probable relations existing 

along this line through the field. The productive area lies in proximity to what is perhaps the principal fault of the Ojai system, which 

here passes along the steep slopes that form the northern walls of 

lower Sisar Canyon. The extent of the development is about a mile 

in length by 400 or 500 feet in width, the direction assumed by the 

wells being approximately S. 71° 45' E., or about the trend of the line 

between the properties of the Bard Oil and Asphalt Company on the 

south and certain others on the north. The collars of the wells are 

but a short distance below the brow of the mesa that extends back to 

the main mass of the mountains on the north, being about 1,500 feet 

above sea level, -or 500 feet above the bed of Santa Paula Canyon.

Only two or three formations outcrop in the Silver Thread field. 

The oldest of these, which occupies the northern portion of the belt, 

represents the upper part of the Topatopa and consists of a series of 

rusty conglomerate, sandstone, and shale, with interbedded quartz-
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. VI

A. FLANKS OF OAK RIDGE AND SANTA SUSANNA MOUNTAINS, SHOWING POST-PLIOCENE

PENEPLAIN. 

From mouth of Sulphur Canyon; looking east,

J{. THE UPPER OJAI VALLEY. 

From crest of Sulphur Mountain, Ventura County
SANTA CLARA VALLEY: SILVER THREAD FIELD. 47

ose limestones, which carry fossils that have been determined to be 

Eocene. These rusty beds are a part of the overturned south tiank 

of the great anticline to the north, and pass directly beneath the 

great body of older Topatopa quartzite and shale that occupies the 

very heart of the range.

The red beds, probably belonging to the Sespe formation, are exposed 

in a narrow belt little more than 100 yards wide, along the upper portion of the face of the ridge north of Sisar Canyon. They outcrop 

south of the rusty beds, passing beneath them, however, with a northerly dip, as part of the overturned series. They consist of coarse 

sandstone, streaked red and white, and shale colored in like manner, 

as in the Sespe region. In the Silver Thread field, as well as in the 

Ojai Valley, there is, stratigraphically below the red beds, a conspicuous layer of white sandstone from 20 to 30 feet thick, which is 

locally bituminous and carries small lenticular bodies of green and 

purplish clay. Stratigraphically above the red beds in the Ojai 

Valley are rusty beds, but these are not exposed in the Silver Thread 

region.

South of the red beds is the Modelo shale, occupying the slopes of 

Sisar Canyon and Sulphur Mountain. The formation here has the 

typical appearance, consisting of earthy to siliceous shale, brown, 

gray, and white in color, more or less organic, impregnated with gypsum, sulphur, and bitumen, and carrying lenses of limestone that 

weather a bright yellow. This shale is thrust down against the formations already described by a displacement, which may be called the 

Silver Thread fault. This is probably the principal westerly branch 

of the San Cayetano break and may be the continuation of the principal 

fault of the Ojai Valley. If this connection is correct, the displacement amounts probably to several thousand feet. Immediately south 

of the fracture the beds are folded into an anticline, the axis of which is 

coincident with the lower part of Sisar Canyon. In Sulphur Mountain 

they lie in a syncline, the axis being coincident with the crest of the 

mountain. A little farther south there is a second anticline, beyond 

which, with the exception of minor flexures, the southerly dip of the 

strata is maintained to the valley of Santa Clara River.

In the bluffs of Santa Paula Canyon, at the base of the oil-yielding 

hills, there is immediately north of the anticlinal axis an outcrop of 

200 or 300 feet of earthy, micaceo-quartzitic shale, chalky in color 

and bearing yellow to gray limestone concretions and thin beds of 

sandstone. This shale resembles the chalky Modelo shale in Hopper 

Canyon and is probably its equivalent. Immediately south of the 

anticlinal axis, at the mouth of Sisar Creek, the more siliceous shale 

sets in. It is possible, therefore, that some faulting has taken place 

along the crest of the fold, so that the series is not the same on both 

sides. On the other hand, it may be that the appearance of the shale
48 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

of northerly dip has been altered by the crushing that it has undergone in proximity to the fault.

The Modelo shale of Sulphur Mountain and the valleys north and 

south is continued east of Santa Paula Canyon in the foothills of the 

Santa Paula Ridge and San Cayetano Mountain; finally, by the convergence of faults, wedging out between the Fernando sediments of 

the foothills and the Topatopa formation of the mountain.

The general strike of the formations north of the Modelo is N. 65° 

W., the dip being 40°-70° N. Adjacent to the Silver Thread fault line 

the Modelo also strikes N. 65° W. parallel with the break, but along 

Sisar Creek the direction changes to nearly east and west, while south 

of Sulphur Mountain it is N. 60°-70° E. Immediately south of the 

main fracture the shale of this formation dips to the north, toward the 

plane of displacement, the axis of the adjacent anticline lying perhaps 

200 or 300 yards farther south.

Although the prevailing dip near the Silver Thread fault is northward, the strata, nevertheless, present more or less irregularity of 

occurrence, the appearance suggesting a fragmental condition.of the 

formations. This may readily be the case along a fracture of such 

proportions, the amount of displacement being hardly less than 5,000 

or 6,000 feet.

OIL WELLS.

J

The oil wells of this district all lie immediately north of the Silver 

Thread fault, which separates the Modelo shale and the Sespe red 

beds. They pierce the red beds, and a few wells in their upper portions pass through the more southerly members of the older but overlying rusty beds that carry Eocene fossils. None of the wells is distant 

more than 200. or 300 feet from the plane of fracture, while one or two 

are especially close to it, appearing, indeed, to have been sunk in 

crushed rock of the Modelo formation; however, in view of the uncertainty as to the dip of the fault plane it may be that they pass at slight 

depth from the fragmental Modelo into the more solid strata of the 

older formations north of the fault.

The maximum depth attained is a little over 1,000 feet. The wells 

are all small, 12 barrels per day being the largest individual yield at 

the present time. The gravity of the oil varies somewhat from we'll to 

well, but the average is approximately 19° B. The color of the oil is 

green. The only flowing wells are those of the Ojai Company, which 

lie west of the others, with their collars at a considerably lower elevation; they are also very shallow and are, moreover, located directly 

in the line of seepage of the region.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. VII

A. SANTA PAULA CANYON, FROM SANTA PAULA, VENTURA COUNTY.

B. ELSMERE RIDGE AND OIL WELLS, NEAR NEWHALL, LOS ANGELES COUNTY.
SANTA CLABA VALLEY I SANTA PAULA RIDGE. 49 

FIELD SOUTH OF SANTA PAULA RIDGE. 

LOCATION.

The productive oil territory immediately east of Santa Paula Canyon lies at the foot of the steep southern face of San Cayetano Mountain and is the eastward extension of the Ojai, Silver Thread, and 

Sulphur Mountain districts. The general configuration of the district is shown in PL VII, A, a panorama looking north from Santa 

Paula, in which this field appears along the face of San Cayetano 

Mountain on the right The sharply eroded ridges in the middle distance on the right are composed of the Fernando conglomerate, sandstone, and clay.

GEOLOGY AND STRUCTURE.

The great San Cayetano fault, along wliich the late Tertiaries are 

in contact with the Topatopa formation, lies at the base of the steeper 

portion of San Cayetano Mountain, at the upper edge of the lofty foot 

slopes, 2,000 feet above sea level.' Along this line the oil-producing 

territory has been found, the area of yield widening somewhat with 

the appearance of other members of the fault system, in the direction 

of Santa Paula Creek. In this direction, too, the succession of strata 

and their relations become more and more complex.

The sediments involved in the productive region east of Santa 

Paula Creek include unmistakable Topatopa beds; a small wedge of 

the rusty Eocene sandstone, shale, and Osfrm-bearing limestone from 

the Silver Thread field; shale of the Modelo type, and a succession of 

sandstone, conglomerates, and blue, mud-like arenaceous clays, that 

have already been referred to as probably of Fernando (Pliocene) 

age. These last are the same as those occurring in Adams, Wheeler, 

and Aliso canyons and are also to be seen in strong outcrops crossing 

Santa Paula Creek from 3 miles above the town of Santa Paula to a 

point within a mile of Sisar Creek. The Modelo is identified by the 

siliceous character of its shales and by their organic life. As it is, 

however, in a locality in which the rocks are badly crushed and in 

which there is a rapid succession of interfault blocks, it is impossible 

to recognize its relations to adjacent beds.

A typical section (see PI. Ill, sec. C-C') of the field, directly across 

the strata from a point about 2 miles east of Santa Paula Creek, 

in the vicinity of the Hartford well, is as follows: On the north the 

typical Topatopa, succeeded across a fault plane by a siliceous shale 

typical of the Modelo. South of this is a large body of brown shale 

with' limestone lenses, which under ordinary circumstances would be 

regarded as also a part of the Modelo, but which is less siliceous and
50 . OIL DISTRICTS OF SOUTHERN CALIFORNIA.

more earthy than many of the Modelo beds. Still farther south are 

Fernando sandstone and conglomerate, which, with shale and clay, 

extend well out beneath the sloping foothills of the range. The strata 

in the fault zone and adjacent to it on the south have a northerly dip, 

varying from 80° in the sandstone and conglomerate just south of 

Bear Canyon and the well area to 50° in the well area itself and to 30° 

in the escarpment of Santa Paula Ridge and San Caystano Mountain. 

The throw of the fault plane separating the Modelo and the Topatopa 

formations amounts, doubtless, to many thousand feet. A second 

fault probably exists in the interval between the Modelo siliceous shale 

and the Fernando sandstone and conglomerate south of Bear Canyon and at the head of Mud Gulch, the intervening brown shale, 

which.is earthy and stained with bitumen, belonging, in the writer's 

belief, to the older formation. The strata south of the second fault 

are probably overturned, and only at a depth of 1,000 or 2,000 feet 

assume their regular dip to the south. This fault is probably the 

easterly extension of that existing along the southern base of Sulphur Mountain, since its trend and that of the adjacent strata is 

N. 65°-80° E., in conformity with the strikes in the latter region. 

The northern fault is doubtless the extension of the fault passing 

north of Sulphur Mountain, its trend and that of the lines of stratification adjacent being N. 65°-80° W. The extent of throw along 

the southern fault is undetermined and may vary from 500 to 1,500 

feet. These two faults come together about 5 miles east of Santa 

Paula Creek, in the vicinity of the Empire wells, and east of this 

point only a single fracture is present.

OIL WELLS.

The wells of this field are confined chiefly to the brown shale and 

range in depth from a few hundred to nearly 2,000 feet. Sandy beds 

undoubtedly occur; but in the main the strata are blue, brown, and 

black shale, with occasional harder layers, known to the drillers as 

"hard shells." The oil is found in the coarser sediments. The 

Empire wells, in the eastern part of the field, show traces of the Fernando sandstone and conglomerate, from which, doubtless, they draw 

a portion of their oil, the remainder coming from the underlying 

Modelo formation. Some of the wells of this field are reported to 

have started at 200 barrels or more, the yield after a short time falling 

off until it is now between 5 and 20 barrels. The oil is light, its 

gravity being 35° B., and of greenish color, resembling in a measure 

that from the same formation in the Puente Hills.

The companies operating east of Santa Paula Creek are the O'Hara, 

the Chicago Crude, the Paxton Gold Bond, the Pure, the Hartford, 

the CunifT, and the Empire.
SANTA CLAEA VALLEY: SESPE FIELDS. 51

SESPE FIELDS. 

LOCATION.

The Sespe fields include' that portion of the territory north of the 

Santa Clara Valley which lies adjacent .to Sespe Creek in the lower 

8 or 10 miles of its course, together with the area about Little Sespe, 

Fourfork, Tar, and Bear creeks and Pine and Coldwater canyons all 

in the Sespe drainage system.

STRUCTURE.

In the Sespe district the formations begin to show crumpling, at 

first gentle, then severe, at the northern border of the Camulos quadrangle. The axis of the-general fold lies just outside the quadrangle, 

while south of the fold is the edge of the broad table of Sespe red beds. 

(See PL III, sec. X-Z'.) In the country adjacent to the table of red 

beds on the south lies the axis of the Coldwater anticline, the lowest 

beds exposed being those at the base of the Sespe formation. The 

. eastward extension of this anticline is somewhat uncertain, but. it 

may prove to be continuous with or closely adjacent to the Ivers anticline, the axis of which is the seat of the Ivers oil wells. Both disappear in the folds at the gorge of Little Sespe Creek. South of the 

Coldwater anticline, confined to the narrow ridge between Coldwater 

and Pine canyons, is a sharply compressed syncline. This is nearly in 

line and may be continuous with the syncline that farther east passes 

through Oat Mountain and becomes one of the principal structural 

features of the region. In Pine Canyon, at the base of the ridge carrying the syncline above mentioned, the Topatopa formation reappears 

from beneath the Sespe beds and with northerly dip constitutes San 

Cayetano Mountain and Santa Paula Peak and the general mountain 

mass of which they are such conspicuous features. The structure of 

this mountain mass is monoclinal, developed, doubtless by faulting, 

from an overturned anticline whose arch could have been but little 

less than that of the main Topatopa fold farther north. The southern 

face of the monocline is a bold escarpment of 2,000 feet, in which the 

strata still show remnants of the arch. The displacement at this 

fault is probably 3,000 or 4,000 feet.

East of Sespe Creek the more important subordinate folds on the 

 flanks of the main flexure include the Oat Mountain syncline, already 

referred, to; an anticline that crosses lower Pole Canyon at the sharp 

turn from south to west; and another anticline, a mile farther south, 

that passes into the valley of Sespe Creek immediately below the 

entrance of Pole Canyon. Each of these folds is a conspicuous feature, but the sj^ncline is perhaps the most marked, involving the strata 

from the Modelo to the red beds of the Sespe. In addition to these
52 OIL DISTRICTS OF SOUTHERN" CALIFORNIA.

there are numerous local folds of but little less importance than those 

just mentioned. One or two of these local flexures are accompanied 

by faults, forming highly-crumpled zones.

The portion of Sespe Canyon lying above its confluence with Little 

Sespe Creek is the seat of marked disturbance. Apparently, there 

has been not only folding in conformity with the general east-west 

trend of the main, anticline, but also a transverse buckling of the strata 

along strike lines that probably took place synchronously with the 

development of the principal folds. This buckling resulted in the sharp 

changes observed in the direction of structural lines and rendered 

still more complex the general folds and faults that affect the strata, 

especially in the angle between the main Sespe Creek and its tributary, Little Sespe Creek, and about the mouth of Sespe Canyon. In 

this region the regularity of the folds described in the preceding paragraphs has been almost completely destroyed, and the real structure 

is determined with difficulty.

The valley of Sespe Creek below the canyon is filled with Pleistocene 

deposits that conceal the older formations. East of the stream, in the 

lower slopes of Oat Mountain, there is a suggestion of the structure 

in the presence of Ostrea-bea,rmg, rusty sandstone and shale, more or 

less calcareous, that closely resemble the rusty beds at the summit 

of the Sespe formation. These beds have a general N. 15° W. strike 

and an easterly dip. The strike becomes northwesterly toward the 

north, the beds evidently crossing the creek and uniting with those 

in the much-crumpled area immediately within the canyon mouth. 

To the south the rusty beds disappear beneath the overlying members 

of the Vaqueros formation, affording indications of a southerly dip 

beneath the valley. It is possible, however, that at this point there 

is a fault which has carried down the Modelo shale, bringing it into 

contact with the lower members of the Vaqueros formation and, perhaps, even with the rusty upper beds of the Sespe.

The strikes and dips here described suggest the east end of an anticline, most of which lies buried beneath the recent deposits of the Sespe 

and Santa Clara valleys. It is possible, too, that the trace of an anticlinal axis in the southern escarpment of San Cayetano Mountain, 

already referred to, may be a portion of the same flexure. In this 

case the San Cayetano fault may merge into this anticline on the east 

or it may die out in the much smaller fracture at the south end of Sespe 

Canyon, suggested in the preceding paragraph.

In the development of the earlier geologic fea'tures in the vicinity 

of the present Sespe Canyon there appears to have been formed, at the 

close of the Miocene, a structural bay, which was later filled with 

Pleistocene and, perhaps, Pliocene sediments. The uppermost Fernando or Pleistocene deposits are those which to-day are exposed in
. SANTA CLAEA VALLEY: SESPE FIELDS. 53

this locality. The lower Fernando is not exposed, but its outcrops 

cover considerable areas to the west and isolated areas also appear 

to the east, notably at the point of the foothills immediately east of 

Fillmore and in the vicinity of Piru. East of Piru the Fernando 

becomes the prevailing formation.

A stratigraphic feature that has considerable significance in connection with the geologic history of the Sespe region is the disappearance of the lower Modelo sandstone. In the area about the head of 

Hopper Canyon this terrane has an enormous development, its thickness amounting to at least 4,000 or 5,000 feet. Within the Sespe oil 

fields, however, its maximum is barely more than 1,000 feet and it 

disappears entirely in the slopes of Sespe Valley south of Oat Mountain. At other points within the confines of the oil fields it passes 

beneath the surface while still strongly developed, and its ultimate 

behavior is of course unknown.

The range south of Santa Clara River is seemingly a development 

independent of, though perhaps synchronous with, the mountains 

north of the river. There is, however, a degree of geologic relationship shown by the recurrence in the lower slopes of Oak Ridge of beds 

that from a paleontologic standpoint are undoubtedly the homologues 

of the lower. portion of the lower Miocene which is encountered on 

Fourfork and Tar creeks. Below this paleontologic horizon in other 

portions of Oak Ridge, particularly to the west, still lower measures: 

are exposed, consisting of brightly banded red and gray sandstone 

and sandy clay and heavier cross-bedded and somewhat conglomeratic 

rusty,sandstone. This series is in general appearance very different 

from the Sespe beds north of the Santa Clara, yet in some of the details 

there is considerable resemblance. It would seem, therefore, that 

the horizons mentioned are repeated in the two localities, but with a 

certain differentiation of sediment and a reduced thickness to the south. 

Suggestions of such reduction are found even north of the Santa 

Clara in the westerly slope of Oat Mountain, where the Vaqueros 

and Modelo formations are perceptibly thinner than in their type 

localities.

The foregoing description of structure about Sespe Canyon is the 

result of a reconnaissance made with reference to the mode of occurrence of petroleum in the several localities in which it has been found. 

Detailed work, careful examination of individual strata for their fossil 

contents, and the tracing of the several horizons should lead to a much 

clearer understanding of the complexities that exist and might even 

alter the present exposition of some of the features. In the main, 

however, it is believed that the view presented is correct, and so far 

as it bears on the occurrence of petroleum it may be accepted.

Bull. 309 07 5
54 OIL DISTRICTS OP SOUTHERN CALIFORNIA.

OIL WELLS.

The wells in the Sespe district may be grouped as follows: Those 

of the Union Consolidated Oil Company in Sespe Canyon, at the base 

of Sulphur Peak; those in the vicinity of Devilsgate, a narrow gorge 

of the Sespe 2 or 3 miles below the Union wells; the Ivers wells, still 

lower in the canyon; the Kentuck wells, also in Sespe Canyon just 

above the mouth of Little Sespe Creek; the Happy Thought wells, on 

the south bank of Little Sespe Creek near its mouth; the Foot-of-theHill wells, on Little Sespe Creek a mile above its confluence with the 

main stream: the Fourfork wells, on an upper branch of Little Sespe 

Creek 2 or 3 miles above the Foot-of-the-Hill wells, and the wells on 

Tar Creek.

UNION CONSOLIDATED WELLS.

The territory being developed by the Union Consolidated Oil Company lies on the north flank of the main Topatopa anticline. At the 

time of the writers visit the company had but a single productive 

well, located at the sharp bend of Sespe Creek opposite a minor 

tributary descending from Sulphur Peak and entering the main stream 

a mile above the mouth of Tar Creek. The purpose of this well was to 

tap the white sandstone at the base of the Sespe formation, a sandstone that here gives forth a considerable seepage of oil. The gravity 

of the oil of this well is about 11° B. A second well was about to be 

drilled by the same company half a mile farther up the canyon, starting in the upper part of the Topatopa formation. It is probable that 

the intention was to obtain a yield from some of the petroliferous 

sandstones in the upper part of the Topatopa, seepages from which 

occur in the river bed a few hundred yards above the location of the 

well.

REGION OF DEVILSGATE.

The oil wells in the vicinity of Devilsgate are located a short distance above the narrows of the Sespe gorge, close to the axis of the 

Coldwater anticline. The major part of this anticline lies west of 

Sespe Creek, the strata in the arch of the fold having been sufficiently 

crushed to determine the position of Coldwater Canyon. The general 

trend of the axis is N. 70° E., with an easterly pitch in the vicinity of 

Sespe Creek. About the end of this anticline the wells of the Russell 

Company have been drilled. The western limit of the anticline is 

not known, but it extends well toward the summit of the divide 

between the Sespe and Santa Paula drainage systems, and may perhaps continue into the upper canyons of the east fork of the Santa 

Paula. The territory that has been proved to be productive along 

this fold is at present confined to its most accessible point, Sespe 

Canyon. The. possibilities for the remaining length of the anticline 

are yet to be determined.
SANTA CLARA VALLEY: SESPE FIELDS. 55

The heart of the Coldwater anticline is occupied by the lower division of variegated strata at the base of the Sespe formation. The 

arch is well exposed in the canyon walls east of the Sespe channel, 

where practically the same succession of beds is to be seen as in the 

region of the Union Consolidated Oil Company's wells 2 or 3 miles 

farther up the canyon, at the base of Sulphur Peak. The lower 

members of the formation, however, are not exposed. ' The arch is 

comparatively symmetrical, and the wells lie on both sides of the 

axis and also of Sespe Creek. They penetrate strata lying below the 

division of greenish-gray shale in the upper part of this member of the 

Sespe, and it is reported that oil is derived from the white sandstone 

at the base of the formation, and possibly also from certain strata 

in the upper part of the Topatopa formation. The source of the oil 

is, therefore, supposedly the same as in the wells of the Union Consolidated Oil Company. The wells, five in number, yield a black oil 

of heavy gravity. One of the wells is said to have produced 40 barrels of heavy oil per day and to have yielded enough gas to run a 30- 

horsepower boiler. Considerable water rises with the oil, but of course 

is easily separated in the settling tanks. No shipments of oil have as 

yet been made from this field, the entire product being consumed in 

the operations of drilling.

IVERS WELLS.

The Ivers wells, located in Sespe Canyon a short distance below 

Devilsgate, are drilled on and near the axis of a local anticline in the 

red sandstone lying about midway of the Sespe formation (see fig. 5).

Scale

100 200 300 feet

FIG. 5. Sketch map showing location of Ivers wells with relation to anticlinal axis in the Sespe red beds. 

Heavy dots, wells .productive in 1902. Figures indicate numbers of wells. Lines show outcrop of 

beds around nose of anticline.

The anticline has a trend of N. 65° W. with an easterly pitch. A 

transverse section of the anticline indicates a dip of about 75° on the 

south limb and 30° on the north limb. The particular horizon 

affording oil is possibly well toward the bottom of the red beds, and is 

at least 600 feet lower than that from which the oil of the Kentuck 

wells, one-half or three-fourths of a mile to the south, is derived.
56 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

The westward extent of the Ivers anticline was not determined, nor 

are its relations to the other folds of the region known. Its general 

trend would carry it toward the mouth of Coldwater Canyon. The 

change in direction exhibited by the numerous folds in this region 

suggests that the Ivers anticline may be continuous with the Coldwater anticline, the main curvature taking place at some point 

between the two groups of wells, probably on the slope toward Coldwater Canyon. On the other hand, the Ivers anticline may be 

merely a local crumple, one of the many that were evidently formed 

in this region.

The Ivers wells are four in number, the oldest having been drilled 

about fifteen years. The early production of this well is said to have 

been about 20 barrels per day, but the four wells together at the 

time of the writer's visit were not producing over 11 barrels. It may 

be added, however, that the condition of the wells was not conducive 

to their maximum possibilities, for they are cleaned only at long intervals. The oil is black aiid is said to vary slightly in gravity from 

well to well, the average being about 17° B. The depth of the wells 

is reported as between 800 and 1,000 feet.

Incidentally it was learned that the cost of production for the four 

wells in 1902 was only about S3 per day, including $2.50 wages paid a 

pumper. Eleven barrels of oil per day at 50 cents yielded $5.50, 

indicating a profit of $2.50 per day, or about $75 per month.

Concerning the extension of the productive area westward along 

this fold there is, of course, a question. Seepages, however, are 

reported for its entire length, or well down the slope on the east side 

of Sespe Canyon above Devilsgate.

KENTUCK WELLS.

The Kentuck wells, in Sespe Canyon, just above the mouth of 

Little Sespe Creek, are unique from the standpoint of their structural location, for they lie along or in proximity to the axis of a 

syncline, which is, moreover, one of the most prominent in the fields 

north of Santa Clara River. It must be said, however, that the 

region is one of exceedingly sharp compression, and it may be due 

to this that local channels and reservoirs conducive to the accumulation of oil have been formed under what might ordinarily be construed as unfavorable structural conditions. Throughout the Coast 

Range are many instances of oil having been obtained from wells 

drilled in highly crumpled strata. _

The syncline in which the Kentuck wells are located'is traceable 

eastward through the summit of Oat Mountain and across Pole 

Canyon to Hopper Canyon, where it perhaps unites with another 

syncline of northeasterly trend, the curvature marking the change 

in direction which is characteristic of all the successive folds encoun-
SANTA CLARA VALLEY: SESPB FIELDS. 57

tered from north to south along this gorge. To the west evidences 

of the syncline are to be- found almost to Devilsgate, and it is possible that in this direction the fold is continuous, though in a curved 

line, with that occupying the ridge between Coldwater and Pine 

canyons. The pitch of the axis of this syncline is toward the east, 

the strata becoming successively higher as distance in this direction 

is gained. This fold is the most prominent lying between the main 

Topatopa anticline and the series of folds which pass across the 

outer hills of this mountain mass.

On account of the unusual structural position of the Kentuck wells 

a sketch of their location with reference to the axis of the syncline 

is given in fig. 6. Although they are identified with the synclinal 

structure it might be said that those on either side of the axis are 

on the corresponding slope of the adjacent anticline, and perhaps

Red "beds

of 

middle Sespe

FIG. 6. Sketch map showing location of Kentuck group of wells in syncline in Sespe red beds. Heavy 

dots, productive wells; circles, dry wells. Lines indicate outcrops around syncline. Figures refer 

. to numbers of wells or to dip of strata.

this is the true way in which to regard them. Although the syncline is a prominent fold, it is, nevertheless, like the adjacent Ivers, 

Coldwater, and other anticlines, subordinate to the great anticline 

of the Topatopa Range, and the effect of the local structure may be 

lost in the general position which it occupies on the flanks of the far 

broader fold. It seems to the writer to be only in°some such way 

as this that the presence of oil here and elsewhere along the axes of 

minor folds and even faults in this region can be accounted for. 

Incidentally, it is worthy of note that along portions of its length 

this syncline, as well as the adjacent folds, is so compressed that the 

plane of its axis is thrown past the vertical, the strata on both sides 

dipping to the north. In the immediate vicinity of the Kentuck 

wells, however, this overthrow has not taken place.
58 OIL DISTRICTS OP SOUTHERN CALIFORNIA.

The horizons from which the Kentuck wells draw their oil are 

about midway of the Sespe formation. The logs of the wells show 

that the strata penetrated are sandstone, with minor layers of shale, 

all of a reddish color. The depth of the wells varies from 600 or 

700 feet to nearly 1,500 feet, and they pass through several zones 

that furnish oil in commercial amounts. The more productive body 

of rock, however, is encountered in the lower half of the drill holes. 

The oil is of a dark green to black color, and its gravity is said to 

be about 30° B. In January, 1906, only seven wells of this group 

were pumping, four on the Kentuck property and three on the Star. 

No. 4 Star was abandoned, because of the oil giving out and water 

coming in.

HAPPY THOUGHT WELLS.

The Happy Thought Oil Company's wells are located in the SE. I 

sec. 1, T. 4 N., R. 20 W., on the south side of Little Sespe Creek, 

immediately east of its confluence with the main stream. The 

wells are drilled in the steeply dipping beds on the south side of the 

syncline from which the Kentuck wells derive their oil. In the 

Happy Thought territory, however, this syncline plunges rapidly 

toward the southeast, so that, considered from one point of view, 

the wells penetrate strata dipping southeastward from a hypothetical anticlinal axis somewhere to the northwest, possibly the Topatopa axis. The wells start, just below the brown sandstone at the 

top of the Sespe red beds, the oil, .it is said, being derived from 

several layers of soft sandy shale between harder impervious beds. 

On account of the steep dip of the rocks and their alternating hard 

and soft composition, drilling on this property is reported to be 

difficult.

The company now has three wells down and is drilling a fourth.

The wells are less than 1,000 feet in depth, the oil being encountered 

at about 500 feet. The production is good at the start, and although. 

falling off after a while, soon reaches a normal rate that is "about 

the average of the other wells in this region. The oil is brown and 

the gravity about 27° B. A 2-inch pipe line connects the Happy 

Thought property with storage tanks at Brownstone, 3^ miles distant, whence the oil is shipped by rail to San Francisco.

 FOOT-OF-THE-HILL OR LOS ANGELES WELLS.

The Foot-of-the-Hill or Los Angeles wells, eight in number, are 

located on Little Sespe Creek about a mile above its entrance into 

the main stream. They are the westernmost wells in the southward sweep of the strata after their passage around the broad east 

end of the general Topatopa anticline. They are also adjacent to, 

yet in strata not involved in, the zone of highly crushed rocks that 

form so conspicuous a feature at the confluence of Little Sespe and
SANTA CLARA VALLEY: SESPE FIELDS.

Sespe creeks. They are, therefore, to be compared with the Fourfork and Tar Creek wells rather than with the Kentuck, Ivers, and 

other wells farther west. Drilling was started in the upper, rusty 

division of the Sespe formation, but the source of the oil is either in 

the lowermost strata of this division or in the uppermost of the red 

beds. The wells are from 800 to 1,600 feet in depth, and their oilbearing zones constitute the fourth general horizon at which oil has 

been found in the Sespe formation. Their source of supply is below 

that of the Fourfork wells, which is, therefore, a fifth horizon in this 

great series of red beds and their associated strata.

While the foregoing statement doubtless covers the general conditions of the occurrence of oil in this vicinity, the fact that the wells

L Los Angeles

C Central } Oil we.lls

H Hawkswing

FIG. 7. Sketch map of I oot-of-the-Hill oil wells, showing location with relation to Little Sespe Creek 

and the geologic formations. Heavy dots, wells productive in 1902. Broken lines indicate outcrops 

around nose of anticline. Figures are numbers of wells or dip of strata.

are in line with a minor anticlinal flexure which appears in the summit of°the ridge to the east must be kept in mind. It is to be observed also that their position is at a point where the strike of the 

beds changes rather abruptly from northerly to westerly; they are 

also in one of the inner concentric belts of strata which are involved 

in the general Topatopa anticline; thus it may be that the conditions 

are almost analogous.to those of an anticline. In conditions somewhat similar to this many productive wells of the Coast Range fields 

have been found. Fig. 7 is illustrative of these conditions. The relative positions of the wells are closely approximated, although the results are not those of an actual survey.
60 OIL DISTEICTS OF SOUTHERN CALIFOBNIA.

At the time of the writer's visit to the locality in 1902 it was impossible to learn the precise depth of the several wells or whether the 

source of the oil was the same in all. The position of certain wells 

on strata following the inner curve, and of others on higher strata 

following an outer curve, taken in conjunction with the actual difference in elevation of about 300 feet, would indicate that possibly the 

oil zone is of considerable breadth and thickness.

FOURFORK WELLS.

The Fourfork wells, 15 in number, are located along one of the 

main branches of Fourfork Creek, a tributary of Little Sespe Creek.

FIG. 8. Sketch map showing location of the Fourfork group of wells on Four.'ork Creek with relation 

to the base of the upper purple beds. Circles, wells productive in 1902. Figures indicate numbers 

of wells or dip of strata.

They are but a little west of the divide between this stream and Tar 

Creek. The altitude of their collars varies from about 2,200 to 2,700 

feet above sea level. Their depth is between 1,200 and 1,800 feet, 

in rocks which strike in general about N. 50° E. and dip 35°-45° SE. 

The strike is, however, but a part of the broad curve which is assumed 

by the strata in their passage about the east end of the Topatopa 

anticline. Stratigraphy and structure are both regular in the vicinity 

of the wells, a complete absence of the minor flexures which form so 

common a feature in other portions of the adjacent mountains being 

noteworthy. It will be recalled' that the succession of strata in this 

vicinity, from the base upward, is the red beds and rusty beds, both 

regarded as Sespe; the purple shale, gray shale, and upper purple or
. SANTA OLAHA VALLEY: SESPE FIELDS. 61

maroon measures (Vaqueros); the siliceous shale (Modelo), and the 

Modelo sandstone. The wells penetrate the lower third of the series, 

starting at horizons in or near the top of the lower purple shale and 

reaching perhaps the lower part of the rusty, calcareous sandstone 

which constitutes the upper division of the Sespe formation. It 

may be even that the upper part of the red beds is reached, red 

sand having been encountered in the bottom of some of the holes. 

Fig. 8 indicates the general disposition of these wells. Their production has been comparatively large, 200 barrels a day being the 

record of several at the start. Within a year, however, most of 

them decreased to about 60 barrels, and at the present time few 

yield more than 20 to 30 barrels- a day and many much less. The 

gravity of the oil is about 32° B. the same as that of the Tar Creek 

wells.

The feature of especial interest in regard to the Fourfork wells is 

their altitude, coupled with the fact that they derive their oil from 

the same general zone, although from a somewhat different horizon, 

as the Tar Creek wells to the east and those of the Foot-of-the-Hill 

district to the west. This indicates an undulation of the oil table 

or the altitude at which the oil stands in the same bed:

TAR CREEK WELLS.

The Tar Creek wells are located in the southwestern portion of the 

Tar Creek amphitheater, which is drained by several tributaries flowing 

directly into this stream, including one of its principal branches 

known as Bear Creek. The wells number between 20 and 30, but 

are now mostly abandoned, their yield having fallen to but 3 or 4 

barrels a day. Originally 100 to 200 barrels was the production. 

Like the wells of the Fourfork region, these also are distributed along 

the curve of the strata as- they bend about the axis of the Topatopa 

anticline. The local strike varies, however, slightly on either side 

of N. 10° E., and the dip is generally between 25° and 30° SE. The 

strata penetrated are apparently somewhat higher than those of the 

Fourfork region, and these are, therefore, the highest wells thus far 

considered in the Sespe region. One at least starts near the top of 

the gray shale about mid way of the Vaqueros formation; the others 

start somewhat lower; a few wells, the shallowest of the group, start at 

a comparatively short distance above the rusty beds of the upper 

division of the Sespe formation. Oil appears to be obtained at depths 

between 230 and 1,700 feet below the surface, in the lower portion 

of the Vaqueros formation or the rusty beds in the upper portion of 

the Sespe. There is evidence, however, that many oil-bearing horizons 

were passed in the younger beds overlying these members. The 

presence of oil in these younger beds is undoubtedly due to the occurrence of fine sands or other porous materials, which are distributed
62 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

through the series and which form the reservoirs for the collection of 

oil from the more shaly members. The logs of some of the wells 

indicate that a considerable amount of sand had been penetrated by 

the drill, but it is probable that the strata are sandy shale of fine 

grain rather than distinct sandstone. Occasionally red sand has 

been reported from some of the wells at depths less than 1,000 feet, 

but it is probable that this is the purple or reddish shale constituting 

the lower part of the Vaqueros formation.

In the field it was thought that a slight local undulation of the 

beds could be detected in their broad sweep about the axis of the 

general Topatopa anticline. A like occurrence was suspected in 

the Fourfork district. Slight as these are, they should not be disregarded in an attempt to collect facts bearing on the conditions under 

which the oil of the Coast Range is found.

The yield of these wells is very irregular and the accumulation of 

oil is readily pumped off. It is reported by the man in charge of the 

wells that they are affected by rain, the yield increasing materially 

after a heavy fall.

POLE CANYON. 

LOCATION.

Pole Canyon, although but 2 miles from Sespe Creek, lies wholly beyond the area of disturbed rocks that are so well developed at the 

entrance to the gorge of the Sespe. Although no productive wells 

have yet been drilled in this territory it is deemed advisable to include 

here a short discussion of its structure, as it connects two productive 

areas and may at some future time be found on careful prospecting to 

be itself an oil-producing region.

GEOLOGY AND STRUCTURE.

PI. II, sec. F-F', is illustrative of the conditions along the lines 

F-F' of the general map (PI. I) which are practically those prevailing 

along Pole Canyon. At the north end of the section, on the eastern 

flank of Hopper Mountain, the southern and western edge of an 

extensive outcrop of Modelo sandstone is seen. South of this outcrop 

is a narrow belt of Vaqueros shale which is locally crumpled into an 

asymmetric anticline. South of the Vaqueros area the Modelo formation reappears, turned past the vertical at the crest of the ridge east 

of Pole Canyon, but quickly regaining its southerly dip in the slopes 

below. At the lower edge of the outcrop there is some confusion in 

the succession of strata and in the dips and it is believed that a slight 

displacement has taken place in addition to an overthrow. The overthrow is best observed in the upper Modelo sandstone, which outcrops in a continuous half circle, the axis of the fold pitching about 

45° SE. In this sandstone also is well shown the principal syncline of
SANTA CLARA VALLEY: POLE CANYON. 63

the region, which may be designated the Oat Mountain syncline, its 

western extremity lying in that mountain. Except for sharp anticlinal crumples near its northern and southern edges, this syncline is 

comparatively symmetrical, the outcropping stratum in the trough of 

the fold being the uppermost shale of the Modelo formation. Immediately south of the southern anticlinal crumple is a second fault, 

designated the Sulphur Mountain fault, its trend being N. 60° W., the 

direction of its hade doubtful, though perhaps to the south, the 

downthrow to the south, and the maximum displacement probably 

more than 1,000 feet. This fracture is traceable diagonally across 

Sulphur Mountain to the bottom of the Santa Clara Valley; it is also 

in direct line with certain sharp crumples in Chaffee Canyon, south of 

the valley, to which, therefore, it may be structurally related. To the 

west the fault passes into the ridge running south from Oat Mountain, 

perhaps continuing to Sespe Canyon and merging with the San Cayetano fracture. Over this portion of its course, however, its identification is next to impossible, for the strata are but a succession of 

shales which maybe either Vaqueros, Modelo, or both. These shales are 

of great thickness and extend southward in unbroken outcrop to the 

Santa Clara Valley, only a narrow fringe of overlying Pliocene separating them from the bottom lands for a mile or two along their front. 

The shales display a number of minor folds, but their predominant dip 

is northward. Just before passing beneath the Pliocene, however, 

this seems to change to southward, more or less in conformity with 

that of the younger rocks. Across the Santa Clara Valley, but at a 

distance of nearly 2 miles, the probable upper members of the Sespe 

and lower members of the Vaqueros appear, but the intervening 

structure is unknown.

In a broad way the folds along the section just described appear to 

divide themselves into three major and half a dozen or more minor 

folds. The major folds include the anticlines at the north and south 

ends of the section, and the intervening syncline; the minor folds the 

crumples on the sides of the syncline. Of the major folds the syncline 

extends farthest toward the area of confused structure at the mouth 

of Sespe Canyon, perhaps being involved in it; the northern anticline 

apparently disappears on the southeasterly slope of the general 

Topatopa fold; while the anticline at the south is lost beneath the 

recent deposits of the Sespe and Santa Clara valleys.

East of the line of the section both major and minor folds in the 

main continue to the center of curvature a mile west of Hopper Canyon, where the strata bend from a northwesterly to a northeasterly 

trend. Indeed, the folds seem in places to bend in like manner or at 

least to pass into others of northeasterly ti;end, similarly developed, 

farther east.
64 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

HOPPER-PIRU FIELDS. 

LOCATION.

The district discussed in this section embraces the territory contiguous to Hopper and Nigger canyons, the lower portion of Piru 

Creek, and its tributaries Modelo, Blanchard, Lime, and Reasoner 

canyons on the west and Santa Felicia and Holser canyons on the east. 

The topography, especially about Hopper Canyon, is very rugged, 

but considerable portions of the district are accessible over the roads 

which follow the canyons. Piru, at the mouth of Piru Creek, is the 

only town of importance in the district.

STRUCTURE.

WEST OF PIRU CREEK.

. Within the drainage area of Hopper Canyon the structure varies so 

abruptly that to indicate it completely would require cross sections 

every quarter or half mile; a general idea of it may, however, be 

gained by the examination of sec. G-G', PL IV, which represents a 

north-south section through Piru Peak.

The Hopper Canyon section proper reveals at its north end a short, 

though pronounced anticline of northeasterly trend, with a narrow 

core of Vaqueros beds exposed at its center and the Modelo sandstone 

arching over and about its end a short distance to the east. In the 

Piru Peak section this anticline is probably represented by the slight 

pucker near the north end. Near the middle of the section is the 

sharply compressed Modelo anticline, showing in massive beds of. the 

lower Modelo sandstone. Between this anticline and that first mentioned are several sharp puckers, the most pronounced being that on 

the syncline which passes south of Piru Peak. For this portion of the 

section the thickness of the Modelo sandstone is estimated at about 

3,000 feet.

The Modelo anticline is one of the most conspicuous of the secondary 

folds in the field. The arch shows to best advantage at the head of 

Modelo Canyon, where the lower Modelo sandstone on either side issharply compressed. The dips are between 60° and 80°, but the 

southern limb of the fold is perhaps a little-steeper than the northern 

limb. The anticline may be traced westward to Hopper Canyon, 

beyond which it either disappears or merges with one or another of 

the folds that occur in the Vaqueros shale. Eastward the fold is 

traceable to Piru Creek, where it seems to disappear, unless it should 

by a sharp curve merge with the Holser anticline, half a mile to the 

south. In the lower portion of Modelo Canyon the upper sandstone 

of the formation, together with the underlying shale, show's marked 

crumpling, the crest of the fold being carried past the vertical. The
SANTA CLAKA VALLEY: HOPPEK-PIEU FIELDS. 65

succession of strata on the two sides of this fold does not appear to 

be exactly the same, the relative proportion of sandstone and shale 

being somewhat at variance. This probably is due to concealed 

faults a short distance south of the axis.

The Modelo anticline is the seat of two important fields of oil. 

One is developed close to and. on either side of the axis of the fold, 

along the upper course of Modelo Canyon and at the divide between 

this canyon and the drainage flowing to the west; the other is developed by the Sunset wells near stream level in Hopper Canyon. Other 

portions of the anticline are as yet undeveloped, but there is no evidence to show that such areas do not contain oil, and it seems probable 

that search by the drill would be rewarded.

South of the Modelo anticline are two successive synclines separated 

by a fault. These appear both on the general section (PL III) and 

on sec. G-G' (PI. IV). The rocks involved are the lower and upper 

Modelo sandstones and the intermediate and overlying shales. The 

evidence of the fault lies in the irregularity of outcrop at the head of 

the south fork of Modelo Canyon, in the succession of strata in Lyons 

Peak and farther west, and in the fractured condition of the beds 

overlooking Hopper Canyon. As exposed at the surface, the fault 

seems to be confined to the shale between the two Modelo sandstones. 

It is difficult to estimate the amount of throw that may have taken 

place, but it is at least 500 feet at the point of maximum development 

and perhaps much greater. To the east the fractured condition of 

the rocks continues for at least half the length of Modelo Canyon 

but here possibly the fault dies out on the southern limb of an exceedingly sharp fold that appears in a prominent knoll just north of the 

gorge, directly in line with the axis of the Modelo anticline. The 

effects of the fold doubtless extend as far east as Piru Creek, possibly 

beyond. The western terminus of the fault is uncertain. South of 

the fault the upper Modelo sandstone appears to have been folded 

into a sharp syncline.

Less than half a mile south of the syncline just mentioned lies the 

Lyons anticline, which is the third important anticline of the region 

and which crosses the lower portion of Nigger Canyon. The arch is 

well shown in the divide immediately east of the Lyons wells in the 

upper Modelo sandstone and the shales immediately above and below. 

The shale is more conspicuous in the heart of the anticline to the west, 

while the sandstone may be seen oh the slopes toward Piru Valley, 

curving about the underlying bed. The trend of this anticline is 

approximately N. 80° E. from Nigger Canyon eastward arid S. 65° W. 

from half a mile west of Nigger Canyon westward. This curve conforms to that of the other folds both to the north and to the south. 

To the east the Lyons anticline was not recognized with certainty
66 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

beyond Piru Creek. Its trend is toward the Holser anticline, south 

of the Holser Canyon, but whether the Lyons or the Modelo anticline 

is continuous with the Holser is undetermined. In general, there is 

great confusion of strikes and dips in the slopes of the hills west of 

Piru Creek for the lower 2 or 3 miles of the valley, and without further details it is impossible to affirm whether or not any of the folds 

are continuous with other folds that appear to the east of the stream. 

In the Hopper Canyon section the Lyons anticline shows conspicuously in the middle Modelo shale. It is probable also that a fault 

has developed along the axis of the fold in this locality, the beds to 

the south having been carried downward several hundred feet. The 

maximum displacement appears to be along the east-west lateral entering Hopper Canyon from the east half a mile above its mouth. The 

fracture seems to have resulted from the excessive local development 

of the anticline into an overturned or reversed fold. The attendant 

displacement accounts for the discrepancy in the distances of the 

Modelo sandstone from the apparent axis of the fold on one side and 

the other, in the line of the Hopper Canyon section. West of Hopper 

Canyon the fault is marked by a zone of highly contorted and fractured strata, having a width of about 400 feet. The direction 

assumed by the fault would carry it directly against the Sulphur 

Mountain fracture a mile farther west at an angle of 60°.

A short distance south of the Lyons anticline the Modelo formation 

is unconformably succeeded by heavy conglomerates and sandstones 

of the Fernando formation. Near the contact east of Hopper Canyon 

the dip of the younger strata is southward. East of Nigger Canyon, 

however, the Fernando beds are overturned, with a steep northerly 

dip, but this probably changes to southerly as the beds pass beneath 

the Santa Clara Valley. From this point the line of unconformity 

between the Fernando and Modelo formations passes, with a curvilinear trend, northward above the mouth of Holser Canyon, remaining 

east of Piru Creek.

At the line of the general section (Z-Z', PI. Ill) the Fernando 

formation is narrow of outcrop and highly inclined, but otherwise 

simple of structure. A short distance to the east, however, it is folded, 

and the folds become more pronounced and extensive across PiruCueek, 

developing into, an anticline of considerable proportions, with several 

minor crumples near by on either side.

The Fernando and underlying beds pass beneath the Santa Clara 

Valley, but although the distance across the valley is less than 2 miles 

the Modelo formation has apparently disappeared on the south side, 

the principal formation in the hills being the Vaqueros, with Fernando 

rocks here and there resting against it above the valley level. This 

occurrence suggests possible faulting along the valley, with overlap of 

the Fernando on the older Miocene beds.
SANTA CLAKA VALLEY: HOPPER-PIRU FIELDS. 67

The fold next north of the Modelo anticline is the syncline that 

passes south of Piru Peak. It may be seen both on the west side of 

the divide and east of the peak in the upper portions of Blanchard 

Canyon. The crumpling is slight and the dip on either side of the 

axis comparatively gentle.

North of this syncline is another anticline of importance, the axis 

of which passes east and west across Lime Canyon. The heart of this 

fold is occupied by the lower Modelo sandstone, which is here exposed 

over an area of 3 or 4 square miles. It is surrounded by the overlying 

shale, which in the divide north from Piru Peak forms scarcely more 

than a thin film. To the east across Piru Creek the shale is succeeded 

by the upper Modelo sandstone, and this in turn by the still higher 

siliceous shale at the top of the Modelo; finally the heavy mass of the 

Fernando sediments sets in, arching about and over the eastwardpitching axis of the fold.

The northernmost fold along this section within the Camulos quadrangle, with the exception of one or two minor crumples, is the Reasoner syncline, the axis of which occupies Reasoner Canyon. This 

flexure disappears, however, in the divide at the head of the creek, 

where the heavy lower Modelo sandstone lies in a broad arch about the 

axis of the Topatopa anticline. To the east the syncline continues for 

an undetermined distance beyond Piru Creek, being conspicuous in 

the Fernando conglomerate and sandstone in the hills between Santa 

Felicia and Devil canyons. Both slopes of the syncline are gentle, 

the dip generally being less than 40°; but there are areas in which this 

is somewhat increased by local crumpling.

The northernmost of the folds described in the preceding paragraphs and others beyond the confines of the Camulos quadrangle all 

fade into or are developed as minor crumples on the general easterly 

slope of the main Topatopa anticline.

Within the region here described the three prominent anticlines, the 

Hopper, the Modelo, and the Lyons, have proved oil bearing, the 

Modelo being the most productive, perhaps on account of its greatest 

development; the Lyons less so, and the Hopper the least. On the 

Hopper fold, however, there is at the present time but a single well of 

low yield.

STRUCTURE EAST OF PIRU CREEK.

The region east of Piru Creek presents a number of approximately 

east-west folds, some of which, particularly the more northerly, are 

continuations of those lying west of the stream already described, 

while others farther south are apparently; restricted almost wholly to 

the area east of Piru Creek, only their extreme points extending westward across the stream. Of the latter, the Holser anticline is the most 

conspicuous. The axis of this fold lies in the hills a little south of
68 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

Holser Canyon. Its trend is slightly north of west. It extends westward across the Piru Valley, perhaps connecting with the Modelo or 

the Lyons anticline, or with both. To the east it was recognized in the 

high knoll near the Ventura-Los Angeles county line, beyond which 

observations in detail were not carried. The surficial formation 

affected by this anticline is the Fernando, consisting of conglomerate, 

sandstone, and clay. Along its axis the coarser strata have at various 

places been impregnated with petroleum, and near one of these, in 

Ramona Canyqn, the Ramona Oil Company is drilling a well, the depth 

at the time of the writer's visit being about 1,000 feet, but only the 

slightest traces of oil have been found.. North of Holser Canyon is 

an abandoned dry well, known as the Crown King.

Between the Holser and Lime Canyon anticlines there is undoubtedly a syncline, but the details were not worked out for the region east 

of Piru Creek. To the south the Holser anticline occupies the 

space quite to the Santa Clara Valley, but on this limb of the fold 

(see PL IV, sec. I-I'), on the southern face of the outer ridge, a short 

distance below its crest, is developed a sharp pucker, by which the 

beds in the lower half of the'ridge are turned past the vertical, having 

a northerly dip.

OIL WELLS.

The oil wells of the Hopper-Piru district comprise the San Cayetano, 

Sunset, Fortuna, Nigger Canyon, Modelo Canyon, Piru Oil and Land 

Company, and Holser Canyon wells. All but the last two groups are 

situated west of Piru Creek.

SAN CAYETANO WELLS.

The San Cayetano wells, three in number, lie near the forks of Hopper Canyon about 3^ miles in a direct line above its mouth and constitute the uppermost development in this gorge. They are drilled in 

the upper portion of the Vaqueros shale, the northernmost well starting but a short distance below the lower Modelo sandstone. The 

maximum depth is 600 feet. In one or another of them, however, oil 

has been found almost from the grass roots down in streaks of sandstone of variable thickness that are interbedded in the shale. With 

the oil has been found considerable water and gas. These wells lie in 

a region of great disturbance, which is attributable, perhaps, to the 

proximity of an anticlinal axis, in the first place, and to a sharp bend 

in the strata from a northwesterly to a northeasterly direction in the 

second place. This latter feature is repeated at the Sunset and Fortuna wells farther down the> canyon. It may be reasonable to infer 

that while each of these three oil-bearing localities is that of an anticline, the curvature of the strata as a feature in the great Topatopa 

system of folds may also have acted favorably on the yield of petro-
SANTA CLAKA VALLEY I HOPPER-PIRU FIELDS. 69

leum in this region, the center of curvature in this case being construed 

as a part of the axis of an anticline. Such an occurrence has been 

encountered at a number of points in the oil fields of the Coast Range.

The anticline on which the San Cayetano wells are located has a 

northeasterly trend from a point a little southwest of the wells to the 

divide between Hopper and Reasoner canyons. The length of the 

fold is, therefore, about 2 miles. Except for these wells the anticline 

is unprospected, but there is no reason for the choice of one location 

over another. As the territory develops it will be interesting to note 

the success of drilling to the northeast of the present field. That the 

anticlines of this region may yield oil in more than one locality is evidenced by the Modelo anticline, which carries the very productive 

territory of the Modelo wells and also that of the Sunset Oil Company.

The yield of the San Cayetano wells is but 4 or 5 barrels of 14° gravity oil, but it is thought that this will increase as drilling is carried 

deeper.

SUNSET WELLS.

The Sunset wells, 11 in all, are located on the east side of Hopper 

Canyon, a short distance above the entrance of a lateral gorge that 

heads against Modelo Canyon. They penetrate the Modelo sandstone, which occurs also in the wells of the Modelo Oil Company to 

the east. The dip of the beds is about 45° N. that is, the wells 

have been drilled on the northern flank of an anticline the axis of 

which has a general N. 80° W. strike. Apparently the anticline is 

the same as the Modelo, although the connection between the two 

has not been traced. The area covered by the Sunset wells is somewhat less than a half mile east and west by 500 to 600 feet north 

and south.

The depth of the wells is generally less than 600 feet. The production is between 3 and 15 barrels per day, with a variable and in 

several wells excessive amount of water. It is thought that the 

production might be considerably increased by cleaning the wells. 

The oil is run into a common tank, and the gravity there obtained 

by the writer was 16.4° B. An initial yield as great as 75 barrels 

was obtained from certain of the wells several years ago. In January, 1906, only five of the wells were being pumped.

The Sunset wells afford another case of production in a region of 

highly crumpled strata and a rapid succession of flexures.

PORTUNA WELLS.

The wells of the Buckhorn Oil and Transportation Company are, 

perhaps, best designated by their early name, Fortuna. The territory is the farthest south of the productive areas in Hopper Canyon, 

lying about 2 miles north of the town of Buckhorn. 

Bull. 309 07 6 .
70 OIL DISTBICTS OF SOUTHERN CALIFORNIA.

This also is a group of wells that has been developed along the 

axis of one of the minor anticlines. (See PI. VIII, 5.) The fold 

has an apparent length of barely 1 mile, and it is in the midst of a 

series of closely spaced flexures. The strike of the anticlinal axis is N. 

50° E., and the wells are distributed along the axis in. almost a 

direct line. Fourteen holes have been drilled to a maximum depth 

of about 1,000 feet. The rocks penetrated are the siliceous and 

earthy shales that lie between the lower and upper Modelo sandstones. In one or two instances, however, the lower portion of the 

upper sandstone, which consists of alternating thin sandstone and 

shale beds, has been perforated. This horizon is the highest that is 

productive in the Hopper Canyon district. The Sunset wells draw 

from strata near the base of the Modelo formation, while the San 

Cayetano wells receive their supply from the upper members of the

2.3.5,6.9 = dry holes

Scale

200 400 feet

FIG. 9. Sketch map showing location of Fortuna wells with relation to the anticlinal axis. Heavj 

dots, productive wells; small circles, abandoned wells. Figures indicate numbers of wells. (See 

PI. VIII, B.)

Vaqueros formation, which in turn are higher than any of the productive horizons in the Tar Creek and other districts already 

considered.

The maximum yield of any one of the Fortuna wells as reported 

is 75 barrels per day, but it is now generally less than 10 barrels. 

The gravity of the oil is about 14° B. Much water is pumped with 

the oil, being separated in tanks at the wells. The oil is pumped to 

storage tanks on the line of railway about 2 miles distant.

The accompanying sketch (fig. 9) illustrates the general distribution of the wells with respect to Hopper Creek and the axis of the 

anticline.
U. S. GEOLOGICAL SURVE BULLETIN NO. 309 PL. '

A. MODELO WELLS. MODELO CANYON, VENTURA COUNTY.

B. FORTUNA WELLS, HOPPER CANYON, VENTURA COUNTY.
SANTA CLAEA VALLEY: HOPPER-PIRU FIELDS, 71

NIGGER CANYON WELLS.

The three wells in Nigger Canyon are owned by L. H. Lyon, of 

Los Angeles. They are located at the head of the southern of the 

two east forks of the canyon and start in strata which are close to 

the line of division between the upper Modelo sandstone and the 

underlying shale that is, they penetrate a zone which is practically 

the same as that from which the Fortuna wells obtain their oil. 

Their depth is approximately 1,000 feet. Oil springs occur in the 

immediate vicinity and may have determined the selection of this 

territory for drilling. The wells are close to the axis of a prominent 

anticline, which is perhaps one of the leading secondary folds north 

of Santa Clara River. This fold has an apparent length of about 

5 miles, but no wells except these have been drilled upon it. Its 

trend in general is about N. 80° E., but varies somewhat from point 

to point. Toward the east, in the direction of Piru Valley, this fold 

has the appearance of passing into the Modelo anticline or one of its 

minor crumples. To the west it is traceable beyond Hopper Canyon, where it becomes more or less obscure in the great body of 

shale which separates the two principal Modelo sandstones and 

where it comes into close proximity with one of the important 

northwest-southeast folds that extend from this point westward to 

Sespe Canyon. Of the Nigger Canyon wells, Nos. 1 and 3 are a 

short distance south and No. 2 is immediately north of the axis of 

the anticline, which at this point trends N. 83° W. These wells are 

from a year to three and a half years old. Nos. 1 and 3 yield each 

5 to 8 barrels per day, but No. 2 was flooded with water, which has 

prevented its being in service. It is reported that in No. 3, at a 

depth of 65 feet, a body of asphalt was encountered, which drilled 

with difficulty. It was hard at the top and of the consistency of 

maltha at the bottom, and is supposed to have filled ajfissure in the 

shale. The oil was found at intervals from a depth of 10 feet to 

the bottom of the wells. Gas occurs in.small amounts, and water to 

the extent of about one-third of the oil has been encountered.

MODELO CANYON WELLS.

The structural feature of chief interest in Modelo Canyon is an anticline in which the lower Modelo sandstone is sharply folded as diagrammatically represented in PI. Ill, sec. X-Z' and PI. IV, sec. G-G'. 

The general aspect of the locality is shown in PL VIII, A. A second 

feature of minor importance is the succession of crushed folds, with 

faults, at the head of the south fork of the canyon, one-fourth to 

one-half mile south of the anticline.

The Modelo anticline has already been referred to, notably in the 

general description of the geology of the region between Hopper and
72 OIL DISTKICTS OF SOUTHERN CALIFORNIA.

Piru creeks. Nowhere, however, is the fold more perfectly and symmetrically developed than at the head of Modelo Canyon, nor is the 

lower Modelo sandstone anywhere more typically represented than in 

this region. The exact horizon of the sandstone that outcrops at the 

divide between the east and west drainage is probably in the lower 

half of the sandstone member, but owing to the steepness of the dip on 

both limbs of the anticline, amounting to 70° or 80°, h\is questionable 

if the wells have penetrated to the base of the formation, although a 

depth of 1,500 feet has been attained.

The length of the Modelo anticline is somewhat uncertain; to the 

west, beyond Hopper Canyon, it may pass into one of the folds of that 

region, while to the east it may prove to be continuous with the anticline that lies immediately south of Holser Canyon. The Modelo 

wells are located about the middle of this fold and on either side of its 

axis. This is one of the few instances in the Coast Range where oil 

wells have been developed midway of a fold or in such close proximity 

to its axis. It may be worthy of note that the Modelo anticline lies 

but a short distance north of a line of sharp crushing and folding, thus 

repeating a relationship between the productive anticlines and faults 

that has been established in several of the California fields, notably 

those of the Puente Hills. The developed area of this district is thus 

far confined to the lower Modelo sandstone, but the structure is continued eastward into the overlying shale and the upper sandstone.

The relative positions of the wells along this anticlinal fold in 

Modelo Canyon, considered with the depths at which oil is obtained, 

are of interest; for instance, between the lowest and the highest well 

there is a difference in altitude of nearly 800 feet; between well No. 

18, the lowest, and No. 19, at an elevation slightly below the highest 

well, there is a distance of perhaps 700 feet; in No. 18, with a depth of 

1,090 feet, the lowest oil occurred at 930 feet; in No. 19 the lowest oil 

was found at 805 feet, at the bottom of the well. This would indicate 

a curve of trie oil table, which corresponds somewhat with the slope 

of the present surface along the anticline.

The general trend of the axis of the Modelo anticline is but 3° or 4° 

north of west, although in approaching Hopper Canyon and the valley of Piru Creek the direction becomes N. 80° W.

The wells of the Modelo Oil Company number 24. One is drilled 

directly in the divide between Modelo and Hopper canyons, two a 

short distance west of this divide, and the remainder east of the divide 

for half a mile down Modelo Canyon. The accompanying three logs 

from the records of the company have been selected to show the composition of the Modelo sandstone. Well No. 14 lies near the middle 

of the group, No. 24 is about 500 feet west of the divide, and No. 18 

is the easternmost well in the proved area.
. SANTA CLARA VALLEY: HOPPER-PIEU FIELDS. 73 

Logs ofv;ells of the Modelo Oil Company. Modelo Canyon and lidmty.

- WELL NO. 14.

Thick- Depth.

Feet. Feet.

White sand............................................................................. 190 190

Oil sand (oil)........................................................................... 210 400

White sand............................................................................. 60

Oil sand (oil)........................................................................... 70 530

White sand............................................................................. 70 600

Oil sand (oil)........................................................................... 35 635

White sand............................................................................. 75 710

Oil sand (oil)........................................................................... 70 780

Water sand............................................................................ , .40 820

Oil sand (oil)............................................................................ 50 870

Water sand............................................................................ 10 880

WELL NO. 24.

Sand rock.............................................................................. 115 115 Adobe.................................................................................. 5 120

Clay... .....................................................-- ...- --- ------ - -- 25 145

White sand............................................................................. 10 155

Adobe.................................................................................. 15 170

Sand rock.............................................................................. 10 180

White sand............................................................................. 315 495

Sand and adobe..................................... I.................................. 45 540

Adobe................................................................................... 5 545

Oil sand................................................................................ 50 595

Water sand.......................................................................'..... 25 620

Sand and adobe........................................................................ 70 695

Oil sand (oil)........................................................................... 10 705

Sand rock..........................................,..."................................ 50 755

Sand and bowlders..................................................................... 120 875

Hard sand............................................................................. 20 895

Water sand............................................................................ 60 955

White sand......................... 1................................................... 15 970

Oil sand (oil)........................................................................... 42 i, 012

Hard sand............................................................................. 23 1,035

Sand and adobe........................................................................ 75 1,110

Oil sand (oil).......................................................................... 35 1,145

WELL NO. 18.

Blue sand.............................'................................................. 121 121

Gray sand (oil at 160 feet)............................................................. 39 160

Black shale............................................................................. 25 185

White sand............................................................................. 45 220

Black shale..... ; ....................................................................... 30 250

White sand (water at 290 feet)......................................................... 45 295

Black shale (water at 316 feet)......................................................... 35 330

White sand............................................................................. 50 380

Clay.................................................................................... 28 408

White sand (gas and water at 495 feet)................................................. 132 540

Clay..................................................................................... 20 560

White sand (oil at 870 feet)............................................................ 310 870

Gray sand............................................................................... 35 905

Shale and sand (oil at 023 feet)......................................................... 25 930

Asphaltic sand........................................................................ 5 935

G ray sand.............................................................................. 65 1,000

Water sand (oil at 1,030 feet).......................................................... 30 1,030

Jlay..................................................................................... 43 1,073

W ater sand................................... I........................................ 17 .1,090

The figures in the first column of the above log represent the distances for which each individual stratum was encountered. As the 

dip of the beds is between 65° and 80°, these amounts are far in excess 

of the actual thickness of the respective beds.

From the log of well No. 18 it seems probable that the thickness of 

the productive sands at the several horizons is slight.
74 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

The logs are given in the vernacular of the driller. It is probable 

however, that adobe and clay are one and the same, except that the 

former is perhaps somewhat more tenacious than the latter. Shale is 

distinguished from clay by being less sticky and more inclined to 

come up in minute slivers. The sands are distinguished by colors, 

but this feature is not significant. The water sands are those in 

which water has been encountered in drilling, and it is to be observed 

that they are in alternation with the oil sands, the two being in places 

adjacent; in places separated by a clay parting; Mr. Sperry, manager of the Modelo Oil Company, believes that at least a thin stratum 

of shale between such sands is the rule. It is difficult to explain the 

alternation of water and oil sands if consideration is given to the supposed transmigration of the oil from its seat of origin in the shales into 

the sandstones, which serve as reservoirs. It has been suggested that 

this alternating occurrence may be accounted for by considering each 

pair of layers the oil above and the water below as occupying an 

isolated channel or reservoir, the segregation having taken place after 

their entrance into the containing strata on account of the difference 

in specific gravity of the two fluids. Nearly all the wells periodically 

pump more or less water with the oil, at times in the proportion of 3 

barrels of water to 1 barrel of oil, at other times in equal amount. 

The continuity of sands bearing water and oil need not be regarded as 

indicating that the two are mixed in their natural occurrence, but 

only that both flow into the well from the same bed, the oil perhaps 

resting upon the water in the reservoir.

The bowlders referred to in the log of well No. 24, between the 

depths of 755 and 875 feet, are unquestionably the concretions that 

characterize the lower Modelo sandstone.

.The yield of the Modelo wells is between 5 and 15 barrels per day, 

and Mr. Sperry states that since 1897 there has been no perceptible 

decrease in the amount. Of course for the first few days the yield 

was considerably in excess of these figures. The oil is black and 

its gravity ranges between 25° and 32° B., with perhaps 28° as an 

average. The wide variation in gravity of the oil from these wells is 

a feature that is difficult to explain.

Strong seepages are found along the canyon in the debris that fills 

the bottom. The sandstone in the arch of the anticline also is dark, 

with bitumen contents, especially on the northern side of the axis.

WELLS OF THE PIRU OIL AND LAND COMPANY.

The productive wells of the Piru Oil and Land Company are located 

in the valley of Piru Creek, about 2 miles northeast of Piru. At present two wells yield oil and one water. They penetrate conglomerate 

and sandstone, with some clay, which are believed from their fossils 

to be the Fernando formation. The general dip of the strata is from
SANTA CLAKA VALLEY: HOPPEB-PIKXJ FIELDS. 75

45° to 60° or 70° S. and the strike varies slightly on either side of east 

and west. The particular horizon in the Fernando is somewhat 

uncertain, by reason of the proximity of the wells to what appears 

to be a line of unconformity between this formation and the older 

Modelo beds. It is, however, undoubtedly well up in the Fernando, 

if the section across the hills in front of the wells and directly north 

of Camulos'is to be taken as a criterion.

The structural position of the wells is also somewhat in doubt, for 

no anticline is encountered along the creek for the distance of a mile. 

On the other hand, there is within half a mile south of the wells a 

marked east-west disturbance, which has at one point the appearance of a syncline, at another of an overturn of the beds adjacent to 

a sharp crumple, and at still another of a fault. About half a mile 

northwest of the wells is the anticline, near the axis of which the 

Nigger Canyon wells are situated. It is possible that the effect of 

this anticline extends as far distant from its axis as this group of wells. 

They are from 300 to 600 feet deep, and undoubtedly their oil is 

derived from the conglomerate and sandstone of the Fernando, a 

horizon higher than any other yielding oil north of Santa Clara River.

The production of these wells is but a barrel or two daily of what 

is said to be 15° gravity oil. The oil is black and thick, and much 

water is pumped with it, separation being effected in tanks.

Several other wells have been drilled on the property of the Piru 

Oil and Land Company lying along Piru Creek, extending from the 

mouth nearly to Reasoner Canyon. These ventures, however, have 

not been crowned with success.

WELLS OF HOLSER, CANYON.

Less than half a mile south of Holser Canyon is one of the more 

prominent anticlines that have affected the Fernando formation east 

of Piru Creek. The continuation of this anticline to the west was 

not determined, but from its position and trend it may pass into the 

Modelo fold; on the other hand, like so many other folds in this region, 

it may spring from the system west of Piru Creek, but maintain an 

independent position east of the stream.

Two wells, the Ramona and New Camulos, are located a little 

south of the axis of this anticline, in tributaries of Holser Canyon, 

and north of the canyon, between half a mile and a mile north of the 

axis, is the Crown King. None of these wells has yet found oil. 

The rocks of Holser Canyon are conglomerate and sandstone, with 

local beds of argillaceous shale. Some of the sandstone shows the 

presence of a considerable amount of bitumen throughout its mass 

and it is probable that drilling operations are conducted here on this 

account.
76 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

OIL FIELDS SOUTH OF THE SANTA CLARA.

GENERAL STATEMENT.

The oil fields south of Santa Clara River involve an area having an 

east-west length of 29 miles and a width of from one-half mile to 4 miles. 

For convenience of discussion the territory is divided into four fields, 

which lie at varying intervals along the front of Oak Ridge and the 

Santa Susana Mountains, none being yet developed on the slopes of 

South Mountain. Enumerated from west to east they are the Bardsdale and the Torrey-Eureka-Tapo fields, on the north flank of Oak 

Ridge; the Pico field, comprising Pico, Dewitt, Towsley, Wiley, 

Rice, and East canyons, along the Santa Susana Mountains; and the 

Elsmere field, containing the Elsmere and Placerita wells, on the 

spurs of the San Gabriel Range. (See PI. V, p. 36.)

The fields are developed along the axes of the Oak Ridge, Torrey, 

Eureka-Tapo, Pico, and Elsmere anticlines. The Placerita wells are 

quite independent of the others and are located on the northwarddipping schists of'the San Gabriel Range. The formations involved 

are the Sespe (Eocene); Vaqueros (lower Miocene); and Fernando 

(largely Pliocene). All of these are productive. In addition the 

schists of the San Gabriel Range afford some oil.

BARDSDALE FIELD. 

LOCATION.

The Bardsdale field, as here described, includes South Mountain and 

Oak Ridge as far east as the vicinity of Chaffee Canyon. As all of 

the proved oil territory in the field lies north of the crest of the range 

the detailed descriptions will deal largely with the northern slopes.

GEOLOGY AND STRUCTURE.

The South Mountain-Oak Ridge anticline extends the entire length 

of the two ridges from which it receives its name. The axis is well 

down on the northwest slope of the mountains, in most places at a 

distance of less than half a mile from the edge of the Santa Clara 

Valley and locally but a few rods away. At the west the axis disappears beneath the valley filling a few miles from the end of South 

Mountain, leaving the extremity of this ridge wholly on the southern 

limb of the fold. At the east the anticline terminates abruptly 

against the northwest-southeast system of folds that sets in at Chaffee 

Canyon and continues thence eastward to Fernando Pass;

The trend of the anticlinal axis varies in sweeping curves between 

N. 65° E. and east and west, displaying a certain degree of parallelism 

with the nearer strikes and with at least one structural curve that on
SANTA CLAEA VALLEY: BAEDSDALE FIELD. ' 77

the southern slope of San Cayetano Mountain, north of the Santa 

Clara Valley. While, therefore, the South Mountain-Oak RidgeSanta Susana uplift is undoubtedly an independent unit of structure, 

its development was very probably synchronous with the mountain 

building to the north. Transversely the fold is unsymmetrical at 

nearly all points, the southern limb having much the gentler dip and 

the strata on this side of the axis showing less severity of crumpling 

than those on the north side. The axis of the anticline is also undulatory, the high points being midway of the length of South Mountain 

and of Oak Ridge.

A transverse section of the anticline at Sulphur Canyon, which 

practically marks the division of South Mountain from Oak Ridge, 

shows between 1,000 and 2,000 feet of ^conglomerate, sandstone, and 

shale that are probably Fernando, and at least 500 or 600 feet of chalk 

rock and siliceous shale which have been described as of the Modelo 

type, but concerning the proper stratigraphic reference of which some 

doubt has been expressed. The shale and "chalk rock" occur in 

the axis of the fold, while the conglomerate and its associated strata 

rest unconformably upon its southern flank, forming the higher portions of the ridges and extending far into the Simi Valley. On the 

northern flank the Fernando beds do not appear, the underlying 

shale extending to the Santa Clara Valley. The anticline is somewhat contracted in the region of Sulphur Canyon, and no beds older 

than those of Modelo type outcrop.. A short distance to the east and 

west, however, the fold broadens perceptibly and lower formations 

are successively exposed.

In South Mountain the lowermost beds are red and gray banded 

sandstone and clay, which are tentatively regarded as the partial 

correlative of the Sespe beds north of the Santa Clara, and hence of 

Eocene age. The formation is here especially conspicuous for its 

brilliancy of coloring and the sharp contrasts therein. At least 500 

feet of strata are exposed opposite Santa Paula, but the formation 

occupies the heart of the anticline and its total thickness may be 

much greater. Overlying these are other heavy sandstone and shale, 

resembling in general aspect certain phases of the chocolate-colored 

and gray-banded beds of the Vaqueros formation farther east and 

bearing fossils similar to those of the Vaqueros. Still higher are siliceous shale and " chalk rock" of the Modelo type, bearing not only 

the customary limestones of that formation,, but also several beds of 

fine-grained, gray sandstone. The "chalk rock "is somewhat more 

conspicuous in South Mountain than farther east. The formation as 

a whole, however, shows the same general characteristics as in Oak 

Ridge, even to the red, lava-like appearance, the probable result of 

the burning of its petroleum content. The shale, with its brilliant
78 ' OIL DISTRICTS OF SOUTHERN CALIFORNIA.

colors, forms the crest of South Mountain, and extends for & considerable distance down its western slope. It is succeeded by the Fernando 

formation. * . Minor crumples appear in South Mountain, but in the main the 

direction of dip is to the south, northerly dips being confined practically to the northern side of the anticline along the edge of the 

Santa Clara Valley.

East of Sulphur Canyon the anticline rapidly opens, and at Grimes 

Canyon (see PI. Ill, sec. D-D7 ) it attains its greatest development. 

Here are exposed, in consequence, lower rocks than elsewhere the 

deep-yellow sandstone that has been described as the possible correlative of the rusty beds in the upper -portion of the Sespe formation 

north of Santa Clara River. Jt is overlain by red and gray banded 

beds, except on the north, where the valley has been eroded through 

these beds and into the older strata below. The yellow sandstone is 

also underlain by red and gray beds, as shown by the logs of the wells 

of the Bardsdale Crude Oil Company. Whether or not the heavy 

mass of red sandstone and conglomerate which constitutes the 

greater part of the Sespe formation north of the Santa Clara is present 

here at still greater depths is undetermined. The formations throughout give evidences of marked change within comparatively short distances, and it may be that the red beds of the Sespe have practically 

disappeared.

Overlying the red and gray beds are rocks which have been identified by their fossils as a portion of the Vaqueros formation, consisting 

of conspicuous and persistent sandstone at the base and summit, and 

chocolate-colored and gray arenaceous shale, with occasional bands of 

limestone between. They bend down over the anticline between 

Garberson and Wiley canyons, and west of a point a little west of the 

mouth of Shields Canyon are adjacent to the Santa Clara Valley. At

Wiley Canyon the axis of the anticline presents a small core of the 

underlying red and gray beds. The outer body of the Vaqueros displays a slight syncline, a flexure that is the beginning, perhaps, of the 

more highly disturbed conditions that exist but a short distance 

farther east. A secondary anticline also occurs well up the slope of 

the mountain between Shields and Garberson canyons, with a length 

of slightly over, a mile.

The Vaqueros is easily confused with the Fernando formation, as 

the sandstone and conglomerate of the two formations bear considerable resemblance. It is probable, however, that the Fernando 

does not appear west of Torrey Canyon, but from that point eastward 

it grows in importance to the east end of the Santa Susana Mountains, where it is very prominent.

Siliceous shale and "chalk rock" of the Modelo type overlie the 

Vaqueros and form the crest of Oak Ridge for nearly its entire length.
 SANTA CLAKA VALLEY: BABDSDALE FIELD. 79

Although in South Mountain this formation appears to contain minor 

divisions of sandstone, these seem to be wanting in Oak Ridge. On 

the southern slope of the ridge, above the shale and unconformable 

with it, are the Fernando conglomerate, sandstone, and clay. These 

for the most part lie well down the slope of the mountain, but here 

and there reach the crest.

OIL WELLS.

UNION AND BAKDSDALE CRUDE WELLS.

A single oil field has been developed in the South Mountain-Oak 

Ridge anticline. It lies opposite Bardsdale, extending along the axis 

of the fold from Grimes Canyon westward for a mile and a half. Two 

companies are operating the Union Oil Company and the Bardsdale 

Crude Oil Company. The territory of the former is adjacent to 

Grimes Canyon; that of the latter is the westward extension of the 

field. The wells of these companies are sunk in the rusty-yellow 

conglomeratic sandstone described as the lowermost formation of this 

district and possibly of Eocene age. The wells are located along the 

highest portion of the anticline, the elevation of any particular bed 

diminishing in both directions along the axis of the fold. The records 

of the wells indicate that oil is found in the rusty sandstone and in. 

the underlying red and gray sandy beds at depths of 300 to 815 feet. 

The total depth of the wells varies from 500 to 1,000 feet. The oil 

is black and its gravity is reported, as ranging from 23° to 32° B., the 

average being about 30°. In one instance an oil of about 17° B. was 

encountered. Occasionally water is pumped with the oil, but this is 

exceptional where a good landing stratum is obtained for the casing. 

Such a stratum is usually found among the red bands 'of the beds 

underlying the rusty sands. These, being generally more argillaceous 

than the gray bands, afford a more nearly water-tight bed. The 

wells of the Union Oil Company have been steady producers for a 

number of years, the decrease reported to the writer being but slight. 

These wells yield a large quantity of gas, which is used entirely for 

fuel. Of the total number of wells the Union Oil Company pumps 

about fifteen, the Bardsdale seven. The foreman of the Union Company remarks that if the gas be retained in one of the two strings 

pumped by them the wells of the other have an increased product, 

and that if the gas is not taken from the wells the pressure in them 

becomes so great as to hold the oil back. Numerous devices have 

been used for drawing out the oil, one of them being the ordinary 

steam ejector.

At several other points in the Oak Ridge anticline wells have been 

drilled, but without success. This may be due in part to insufficient 

depth and in part to their location beyond the oil zone. In Garberson Canyon, for instance, a well has been drilled to a depth of over
80 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

1,800 feet, producing nothing but water. In Shields Canyon, however, west of Garberson, a trace of oil was found at 500 feet, the total 

depth of the well being 850 feet. The gravity of this oil is said to 

have been 29.5° B., but much water was encountered with it.

TORREY-EUREKA-TAPO FIELDS. 

LOCATION.

The district discussed in the following paragraph embraces Oak 

Ridge east of Chaffee Canyon and the western portion of the Santa 

Susana Mountains as far east as the head of Tapo Canyon. Within 

it are three productive areas those of Torrey, Eureka, and Tapo 

canyons.

GEOLOGY AND STRUCTURE.

As will be gathered from the description of the geology of the 

Bardsdale district, there is a marked regularity in the stratigraphic' 

succession of the formations and in the anticline into which they have 

been thrown from the west end of South Mountain to Chaffee Canyon. 

Here, however, the regularity ends. The region between Chaffee and 

Tapo canyons shows a highly complicated geologic structure, and 

there is great confusion in the stratigraphic succession, resulting from 

the presence of folds and faults and the difficulty of distinguishing 

between formations, owing to a lack of distinctive characteristics in. 

the beds and to changes in the relative proportions of the coarse and 

fine sediments from point to point.

The first break in the regularity that exists to the west appears in 

a small gulch at the foot of Oak Ridge immediately west of Chaffee 

Canyon. At this point the end of what for convenience may be

termed the Chaffee syncline appears in "chalk rock/'siliceous shale,

and limestone that are believed to be of the same formation as similar 

rocks which form so great a portion of the summit of Oak Ridge, 

having been brought into this position, almost at the edge of the valley,, by arching over the axis of the Oak Ridge-South Mountain anticline. The general trend of this syncline is about S. 30° E., the dip 

on either side averaging perhaps 35°, although steepening sharply as 

the axis is approached. The syncline increases in prominence as it 

crosses the drainage of Chaffee Canyon, and at the summit of the 

ridge at its head becomes a conspicuous feature in the crest line. 

The details of this syncline have not been gathered in full, but apparently the heavy fossiliferous sandstone which outcrops in bold escarpments in Wiley Canyon plunges beneath the axis to reappear on the 

northeast side in the ridge that separates Chaffee and Torrey canyons. 

The conditions observed in Chaffee Canyon suggest that only the 

lower beds of the siliceous shale and " chalk rock" are involved in the
SANTA CLAEA VALLEY: TORREY-EUREKA-TAPO FIELDS. 81

fold, although at the southeast end of the syncline, on the southern slope of Oak Ridge,, a considerably greater thickness has been 

folded in.

The direction of the Chaffee syncline is at variance with that of 

every other fold that has been observed in the ranges south of Santa 

Clara River. Moreover, it lies between two systems of folds, either 

of which might be said to terminate against it. One of these systems 

includes the anticline traceable from Wiley Canyon westward to the 

end of South Mountain; the other is that passing from the region of 

Torrey Canyon in a S. 65° E. direction to the west end of the Santa 

Susana Mountains. It is worthy of note, too, that the position of the 

Chaffee syncline is nearly in direct line with the principal fault in the 

hills north of the Santa Clara.

In the region of Torrey and Eureka canyons the geology is extremely 

complicated, but the general facts appear to be as follows: The formations exposed include 150 or 200 feet of red and gray banded 

sandstone and arenaceous clay of the Sespe, about 600 feet of fossiliferous sandstone and chocolate-colored and gray sandstone and 

shale of the Vaqueros, perhaps 400 feet of siliceous shale and chalk 

rock of Modelo type, and a great body of heavy-bedded sandstone 

and conglomerate, in some of which have been found fossils identifying 

them as the Fernando (Pliocene). These formations are shown in a 

section of Oak Ridge across the Torrey field the oldest beds at the 

heart of an anticline at the northern edge of the productive area, the 

youngest on the southern slope of the ridge and again at its northern 

base, the siliceous shale and "chalk rock" at the mountain crest, and 

the Vaqueros on the upper and lower middle slopes of the northern 

front.

The structural lines of the Torrey field have a trend approximating 

N. 65° W., contrasting in this respect with those of Oak Ridge to the' 

west and in harmony with those to the east, the dividing line between 

the two systems being the Chaffee syncline, already described.

The principal fold of the Torrey field (see PL IV, sec. H-H') is an 

anticline that crosses the ridge between Torrey and Smith canyons 

at the summit of the easterly grade leading to the developed territory. 

This anticline has not been traced eastward to the edge of the Torrey 

basin, but directly in line with it at this point is a similar fold, which 

is probably its continuation. To the west the anticline crosses Torrey 

Canyon, being particularly conspicuous in its lower slopes, becoming 

less so in the ridge between Torrey and Chaflfee canyons, and disappearing to a mere trace in the lower portion of Chaffee Canyon as it 

approaches the Chaffee syncline. The trend of this anticline, which 

may be designated the Torrey, is N. 65° W. The inclination of the 

strata on either limb varies from point to point, but in general may
82 OIL DISTEIGTS OF SOUTHERN CALIFORNIA.

be taken at about 35°. Southward from the axis the dip is compara-. 

tively regular to a point beneath the summit of Oak Ridge. To the 

north, however, the dip continues but a short distance when it gives 

.way to a southerly dip, the syncline thus formed being hardly less 

conspicuous than the anticline itself.

The formations exposed in the Torrey anticline include, at the axis, 

a small outcrop of red and gray banded beds, believed to be the Sespe 

formation; overlying these is the principal formation of the field, heavy 

sandstone and chocolate-colored and gray-banded shales, which, by 

their fossils, have been identified as lower Miocene (Vaqueros), nearly 

1,000 feet thick; succeeding these, on the south the siliceous shale 

of the Modelo, which forms the crest of Oak Ridge opposite the Torrey 

field, and on the north the siliceous member apparently being 

wanting the heavy sandstone and conglomerate that are regarded 

as the Fernando. The Fernando is, however, of small extent in this 

vicinity, becoming prominent in the region of Tapo Canyon and 

attaining its maximum development several miles farther east, opposite Pico Canyon and beyond.

A second anticline in the Torrey field lies in the lower slopes of the 

hills and is probably the west end of that believed to exist along the 

channel of Eureka Canyon, this, in turn, being continuous with the 

main Tapo anticline farther east. This fold may be seen to advantage in the west wall of Torrey Canyon, midway between its mouth 

and.the/orks half a mile up. East of this the flexure is not quite so 

pronounced and is, therefore, not so readily and perhaps not so correctly 

defined. Between Eureka and Torrey canyons the axis of the fold 

pitches to the west, while the strike of the beds is generally north and 

south. There is considerable doubt concerning the structure and the 

succession of the strata in Eureka Canyon. At first glance the regularity appears to be unbroken from the crest of Oak Ridge to the outer

face of the lowermost foothills, the entire cross section, except at the 

summit of the ridge, presenting a southerly dip. From the region of 

Tapo Canyon, however, the main anticline may be traced with only 

slight irregularities to the divide between the-Tapo drainage and that 

of Eureka Canyon, but at this point there is a sharp change in the 

position of the strata, as if the anticline had been severely compressed 

and the plane of its axis had been pushed northward with a dip of perhaps 60° to 90° to the south. (See PL IV, sec. I-F.) In the higher 

portions of Eureka Ridge, a short distance north of this anticline, 

there is a syncline of secondary importance, which also has probably 

suffered strong compression. The resultant position assumed by the 

beds thus influenced by the compound flexure described is one of 

southerly dip, with local obliteration of the axes of both folds, and an 

apparent continuous succession of strata from base to summit of the 

mountain. It is evident, however, that if this should prove to be the
. SANTA CLARA VALLEY: TORREY-EUREKA-TAPO FIELDS. 83

correct structure there is a duplication of beds in the cross section 

referred to. At the mouth of Eureka Canyon there is an exposure 

of Fernando conglomerate and sandstone, bearing fossils identifying 

them with the beds of Packard Hill, near Santa Barbara. Their dip is 

vertical, the change from the. southerly dip of the older strata immediately south being somewhat abrupt. This is probably due to unconformity rather than to a structural break. The Eureka-Tapo anticline appears to be coextensive with the Torrey, a mile to the south. 

Neither has been traced from one end to the other, as delineated on 

the map (PI. I), but by reason of the alignment of several folds 

observed independently it is thought that all are parts of a single 

crumple. As in the case of the Torrey anticline, productive territory 

has been developed in proximity to the axis of the Eureka-Tapo fold, 

the western field being that near the mouth of Eureka Canyon, the 

eastern including several branches of Tapo Canyon. 

- Between the two anticlines thus described is a syncline which has 

not been traced through from west to east, but which is supposed to 

be continuous, as represented on the map. It may be seen on both 

sides of Torrey Canyon, but in the eastern wall of Smith Canyon the 

fold, which is so pronounced to the west, is considerably obscured, 

perhaps by faulting along its axis. A sharp disturbance of the strata 

is recognizable in a vertical cliff of shale and' sandstone directly across 

Smith Canyon from the easterly grade to the Torrey .wells. In the 

line of the syncline, also, there is a similar flexure near the summit'of 

Oak Ridge, and this in turn is in line with the Tapo syncline, a flexure 

a few hundred yards south of the main anticline in Tapo Canyon.

There are other folds of minor importance in this region, here and 

there, sharp or even developed into faults of small extent. The larger 

folds that have been described converge near the mouth of Chaffee 

Canyon as they approach the Chaffee syncline.

The formation chiefly involved in the flexures of the Torrey-Eureka 

region is that of Vaqueros age. To the south in the higher portion of 

Oak Ridge the siliceous shale of Modelo type is also involved in a 

minor degree. On the southern slope of .the main ridge, near the 

Torrey road, the general dip, aside from numerous minor crumples, is 

northward, and a short distance north of the outcrop of the Fernando 

formation a sandstone suggesting one of the Vaqueros beds occurs in 

a position not at all out of harmony with the general structure. The 

actual correlation of this bed, however, remains undetermined and it 

has not been indicated on the map. North of the Vaqueros area, at 

the foot of Oak Ridge, is the Fernando, which also is involved in the 

general folding that has taken place.

It is possible that faults occur within the area of the folds referred 

to in the foregoing paragraphs. The greatest disturbance appears to 

have been in the line of the syncline separating the Torrey and
84 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

Eureka-Tapo anticlines, in the eastern rim of the Torrey amphitheater, the facts pointing to an elevation of the strata north of a 

possible plane of fracture.

The Tapo anticline is traceable for 3 or 4 miles across the northern 

spurs of the easterly portion of Oak Ridge, its axis lying from one-half 

to two-thirds the distance from base to summit. The general trend 

of the fold is about N. 70° W., the dip of the strata on either side of the 

axis varying between 75° and 85°. The heart of the anticline is occupied by a mass of brown shale and interbedded concretionary sandstone. These are believed to be the equivalents of the banded chocolate-colored and gray sandstones and shales in the vicinity of Wiley 

Canyon and farther west, and, if such is the case, are of Vaqueros age. 

On the other hand, the concretionary phase of the sandstone resembles the lower Modelo formation north of the Santa Clara, but no fossils 

have been found to decide the point. Many of the sandstones of Tapo 

Canyon are highly bituminous, and along the crest of the flexure in 

the several forks occur seepages of petroleum of considerable size. In 

the main canyon, either on the axis or slightly to the south of it, is a 

gas well, but its depth and the horizon from which gas is derived are 

unknown.

The Tapo anticline appears to die out toward the east in a mass of 

crushed strata at the head of the westernmost branch of Salt Creek on 

Santa Susana Mountain. In a westerly direction the geologic conditions are somewhat uncertain, but in,the ridge separating West Tapo 

and Eureka canyons the axis has the appearance of bending rather 

sharply to the north. On the other hand, as already suggested, the 

geology of Eureka Canyon and the adjacent slopes is very complicated, 

and for a definite conclusion concerning the relations of the thousands 

of feet of very similar beds additional field work is necessary. The 

position of the Tapo anticline is but tentatively indicated on the map 

(Pi. I).

Between 100 and 200 yards south 'of the Tapo anticline is a syncline which is pronounced in the region of the main forks of Tapo Canyon, but which west of this disappears in the general crumpling on the 

higher slopes in front of Oak Ridge. In an easterly direction its axis 

approaches that of the anticline, and both are apparently lost in a 

common mass of crumpled strata at the end of the Santa Susana 

Mountains.

The zone of excessive crumpling, embracing the Torrey and Tapo 

anticlines and their associated synclines, passes from Oak Ridge into 

the west end of the Santa Susana Mountains, in part also crossing the 

crest of the range at the low point opposite the head of Tapo Canyon. 

In the region thus indicated the disposition and succession of the 

strata are very anomalous, and from a topographic standpoint there 

is a distinct offset in the alignment of the two ranges, the west end of
SANTA CLARA VALLEY : TOREEY-EUREKA-TAPO FIELDS. 85

the Santa Susana lying a little farther north than the east end of Oak 

Ridge. The topographic relation of the mountain ridges may be due 

to the development en e'chelon of successive anticlines, but the anomalies of stratigraphy suggest the presence of a strike fault a little south 

of the Tapo syncline. For instance, in the northern slope of Oak 

Ridge between the Eureka and Tapo drainages, the apparent succession of beds is quite the reverse of the normal. Both the siliceous 

shale of the Modelo and the chocolate-colored shale and sandstone of 

the Vaqueros maintain a northerly dip, and the inference is that the 

latter are the younger. It is probable, however, that along the line 

indicated there has been displacement, the strata south of the fracture 

plane having been depressed, though to what extent is yet- undetermined. This would agree with the explanation already suggested of 

the positions assumed by beds about the head of Smith Canyon. 

South of the Santa Susana Mountains the line of the fault is marked by 

great complexity of strata, it being impossible to recognize horizons 

and, in consequence, the relations of the beds. The fault plane from 

Tapo Canyon eastward appears to lie somewhat diagonal to the general trend of the formations; the area of siliceous shale, a prominent 

feature to the west, is diminished almost to disappearance', and the 

difficulty of correctly interpreting the structure is even further 

enhanced by the approach of the line of unconformity between the 

Vaqueros and Modelo beds and the Fernando formation. The Vaqueros beds are, however, chiefly involved in the .crushing south of the 

range crest. The breadth of the zone of severely crushed and folded 

strata is hardly'less than a mile, while its continuity can be traced for 

a distance of at least 10 miles.

The axis of a somewhat prominent anticline, trending a little south 

of east, passes through the knoll at the southeastern extremity of Oak 

Ridge, about three-fourths' of a mile north of the parallel 34° 20' N. 

and 2 miles west of the meridian 118° 40' W. The eastern half of the 

fold involves the Fernando formation, but the western half lies almost 

wholly within the area of siliceous shale, though not far from the northern edge of the Fernando. The general trend of the axis is more 

nearly east and west than the direction assumed* by the zone of crumpling. These two features therefore diverge toward the west, the zone 

of crushing and fracture turning to the north of Oak Ridge, the anticline passing to the south.

In addition to the foregoing, .there are many other minor crumples 

of greater or less breadth and linear extent, particularly within the 

area of siliceous shale. All have a general 'direction of S. 70°-S5° E., 

but their continuity has not been traced out.

The formation in the middle fork of Tapo Canyon from which oil 

is derived is a succession of sandstone and shale. The sandstone is 

generally thin bedded, and its proportion to the shale diminishes 

Bull. 309 07 7
86 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

toward the base of the series. Concretions, some of them compara-. 

tively large and rounded, characterize certain horizons. The shale is 

for the most part earthy or sandy, but through it may be traced bands 

of harder and in some jplaces even siliceous rock. Limestone concretions are also sparingly present. Both shale and sandstone have been 

more or less impregnated with petroleum, as well as with iron and 

salts of other minerals. Along the axis of the anticline, wherever 

crushing has been particularly severe, occur important seepages of 

petroleum.

Overlying the thin-bedded sandstone and shale, with comparatively sharp passage from the one to the other, is heavy-bedded sandstone divided by minor layers of sandy shale. The sandstone is gray 

to yellow in color, although yellow appears to characterize more generally the lower beds. The sand is coarse and locally gritty or even 

pebble bearing. Well up in the mass conglomerate appears, becoming 

in the outer ridges of the Santa Susana Mountains, a conspicuous feature in the geology. The sandstone and shale in the lower 1,000 feet 

of this younger formation have been impregnated in varying degree 

with petroleum, and from some of them come seepages, indicating 

considerable richness. From one or another member of this group of 

beds is derived the oil in the producing wells of Tapo Canyon.

Conformability appears to exist throughout the succession of strata 

above described, from the lowest, encountered in the heart of the anticline, to the highest, observed at the outer edge of the range. It is 

difficult, therefore, to recognize any true basis on which to segregate 

the beds into distinct formations, yet in a broad way they are separable into a mass of conglomerate and associated heavy-bedded sandstone and shale which bear a distinct resemblance to the Fernando of 

other localities in the Santa Clara district on the one hand, and thinbedded sandstone and shale of a siliceous character, which closely 

resemble the banded chocolate-colored and gray shale and sandstone 

farther west in Oak Ridge and the Modelo in the range north of the 

Santa Clara on the other. For the sake of mapping, the dividing line 

has been taken at the lower horizon of the heavier conglomerate in the 

main Tapo Canyon, a quarter to half a mile above its mouth, occurring 

somewhat farther up on the streams to the east and somewhat lower 

down on those to the west.

OIL WELLS.

The oil wells in the territory just described comprise, in order from 

west to east, the Torrey, Eureka, and Tapo groups, each being designated by the canyon in which they are drilled,
SANTA CLARA VALLEY : TOHREY-EUREKA FIELDS. 87

TOHRKY WELLS.

The productive territory of the Torrey anticline,.forming what is 

known as the Torrey field, embraces an area of about 1 square mile, 

the length being twice the breadth and lying with the strike of the 

rocks, which gradually bend from N. 65° W., the direction prevailing 

on the side of the flexure, to northwest, north northwest, and north as 

the strata round its end. The axis of the anticline passes close to the 

northern edge of the field, the wells, with a few exceptions, having 

been drilled in the strata of gentler dip, 30° to 40°, south of the axis. 

In all there are between 50 and 60 wells, aligned in seven or eight'concentric arcs, in accordance with the curves assumed by the outcropping strata. The wells nearer the axis penetrate the red and gray 

banded argillaceous sandstone that has been correlated with a portion 

of the Sespe formation, while those more distant are perhaps entirely 

confined to the sandstone and shale of 'the Vaqueros.

It is said to be usually impossible in this field to identify horizons 

in one well with those in another, even though the two locations are 

adjacent. The oil sands also vary in thickness from a few feet to 150, 

and even the thicker beds; it is reported, can not be identified from 

well to well. It is, however, the opinion, of the writer that considerable order might be worked out with the aid .of carefully prepared 

cross sections.

The oil has a gravity of 30° to 35° B. and resembles that derived 

from the same formation north of the Santa Clara, especially that from 

the region of Fourfork and Tar creeks. The depth of the wells varies 

from 600 to 2,000 feet, the deeper wells being those farther away from 

the axis of the fold. North of the Torrey anticline the productive 

territory is apparently confined to the east end of the field where the 

distance from the syncline immediately north and from the fracture 

possibly accompanying it is greatest.

Concerning the extent of the Torrey field beyond the present developed area, it may be said with some degree of assurance that to the 

west and north it is likely to be limited by structural conditions to 

nearly the existing lines. In the other directions no prediction can 

be made.

EUREKA WELLS.

The wells of Eureka Canyon are located in its lower reaches, most 

of them being grouped at the sharp turn half a mile above its mouth. 

The geology of the immediate region is somewhat doubtfu'l, but if the 

structure is that of a highly compressed compound fold, as suggested 

on. page 82, the locus of the wells is not far from its anticlinal axis; 

moreover, the developed territory is in the vicinity of a prominent 

curve in the stratification planes, the axis having been pushed somewhat northward between Eureka and Torrey canyons. The wells
88 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

penetrate the Vaqueros sandstone, conglomerate, and shale, but 

whether any of the beds are duplicated it is impossible to determine. 

Such duplication may have taken place, but it has had practically no 

effect on the productiveness of the territory. The wells are located 

a little over a mile north northeast of the Torrey group, the geology 

of the two fields being quite distinct.

Twenty-one wells were in operation or drilling at the time of the 

writer's visit. They vary in depth from 600 to 1,200 feet, and the 

strata passed through, according to the logs, embrace sand, arenaceous shale, dark, adobe-like clay, and the usual "hard shells'' of the 

drillers. The character of the beds varies every 50 to 125 feet in 

depth, but sandstone predominates. Oil sand, so-called, appears to 

be encountered at depths of 540 to 620 feet. Water is found both in 

the upper parts of the wells and beneath the lowermost oil sand recorded. Well No. 20, of the group at the turn of the canyon, is the 

only one in which pebbles are reported. These are, perhaps, a local 

development of one of the more prominent sandstones that lie near 

either the summit or the base of the Vaqueros beds. Usually but a 

single oil sand shows in a well, and it is the opinion of the superintendent that the producing horizon is the same throughout the field.

The gravity of the oil averages, it is said, 24° B., but in some 

instances rises to 26°. This difference, as compared with the Torrey 

oil, is inexplicable, for both are believed to be derived from the same 

formation. Their horizons, however, may be different, and in the 

Eureka field the sediments appear to be coarser, while the strata are 

far more fractured, if the interpretation of the geology here given is 

correct. The latter feature would tend to permit the easier escape of 

the lighter hydrocarbons, leaving behind the heavier oils, which now 

constitute the product.

The yield has been from 1 to 40 barrels per day. The field has, 

however, never been one of large production, but from the records the 

wells appear to have maintained their supply with remarkable uniformity. The log of one of these wells is appended:

Log of well in Eureka Canyon.

"Hard shell," this marking the top of the oil sand, according to the driller's statement.

Thickness.

Feet. 

50

25

265

135

50

35

15

10

245

160

127

Depth.

Feet. . 

.50

75

340

475

525

570

585

595

840

1,000

1, 127
SANTA CLABA VALLEY: TAPO FIELD. 89

No evidence of the red and gray banded series of probable Eocene 

age has been found in any of the holes in this field.

TAl'O WELLS.

Wells have been drilled in the main fork of Tapo Canyon and also 

in each branch of a westerly tributary. Those at present producing 

lie along the east fork of this tributary. They are four in number, 

although from their designation, Nos. 12 to 15 inclusive, it is to be 

inferred that several others have been in existence in earlier days. 

Indeed, one or two of these old wells still contain a slight amount of 

oil. The producing wells are sunk in northward-dipping sandstone 

and shale a mile north of the axis of 'the Tapo anticline. They yield 

at present from 5 to 40 barrels of oil per day. The gravity is 20° to 

24° B., the 20° oil being produced by the well highest up in the canyon 

and lowest as to the strata penetrated. These wells are about 200 

feet apart and range in depth from 460 to 1,200 feet. The oil sand is 

encountered at 235, 465, 940, and 865 feet, from the well farthest up 

the creek to that lowest down, respectively. The wells lowest on the 

dip are the greatest producers. The dip of the measures is from 50° 

to 60°, and it is impossible to say that a single bed produces oil for the 

entire field, although this is suggested by the increasing depths of the 

wells in the direction of the dip. More or less water is pumped with 

the oil, and it is the opinion of the superintendent that the two are 

mined and come from the same bed. The amount of water, however, is slight, the proportion being given as 1 of water to 4.0 of oil. 

Inasmuch as water-bearing sands overlie the oil sands it may be that 

a leak occurs which would account for its presence with the oil. 

Water was also found beneath the oil sand in the well farthest up the 

gulch and has been encountered in some of the wells now abandoned. 

All the wells yield gas, the deeper the well the greater the quantity. 

' The whole of the lower half of the Vaqueros strata exposed in Tapo 

Canyon shows a greater or less impregnation with petroleum. No 

unusual amount appears to have been assembled in proximity to the 

axis of the main anticline, and it may be that the productive territory 

is a particularly rich portion of the series of beds which, from some 

cause or other, has held its oil better than the great mass of the beds 

in the region. From the surface no reason can be seen for the enrichment of one portion of the formation over another portion, and except 

for strong seepages in proximity to the wells one locality might as' 

readily have been chosen for development as another.

The logs of the Tapo wells show a succession of blue clay, brown 

shale, gray sandstone, fine to coarse, and in one instance a trace of 

conglomerate. The thicknesses of these several materials, which are 

constantly repeated, vary from 5 to 200 or more feet, the average 

being, perhaps, between 20 and 75 feet.
90 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

PICO FIELDS. 

LOCATION.

The Pico district, the western part of what is popularly known as 

the "Newhall district," comprises the region of the Santa Susana 

Mountains from Tapo Canyon to Fernando Pass. The Newhall district is divided into the Pico and Elsmere districts for the purpose of 

this discussion, the geologic conditions in the two subdistricts being 

quite different.

GEOLOGY AND STRUCTURE.

In the body of the Santa Susana Mountains there are man}7 flexures in the siliceous shale of the Modelo and in the shale and heavy 

sandstone of the Vaqueros. Certain of these flexures along the 

northern front of the range have become of primary economic importance from the development of rich oil-bearing territor}7 adjacent to 

their axes. With these alone the following pages have to do. (See 

PI. IV, sees. J-J', K-K', L"-L-L/, and M"-M-M'.)

Chief among such folds is one which may be designated the Pico 

anticline. This extends for perhaps 10 miles along the northern 

front of the range. Its trend is N. 60° W. and the strata on the 

southern limb dip 25° to 30°, on the northern limb 50° to 70°. At 

the.west the anticline originates in the divide between the waters 

of Pico and Salt canyons. The east end passes out of the range a 

mile or so south of Fernando Pass, the actual terminus being apparently in the foothills of the San Gabriel Range, or in the valley edge 

immediately adjacent. The axis of the anticline may be seen in 

any of the canyons of the Santa Susana Mountains draining to the 

Santa Clara. (See PI. IX, ./?.) Its trend is somewhat irregular, 

though in its entirety the fold maintains the direction given very 

closely. In the hills between Dewitt and Pico canyons a minor 

fold of the same nature branches off to the north, but this in few 

places amounts to more than a pronounc.ed pucker in the beds 

affected by it. The Pico anticline is traceable at least to Wiley 

Canyon, and perhaps even to the forks of Rice and Gavin canyons. 

South of the main fold is a syncline which parallels it for its entire 

length. This originates at the west at about the same point as the 

anticline, in a mass of highly crumpled strata in the divide between 

'Pico and Salt canyons. After a divergent course of 2 or 3 miles the 

anticline and syncline lie parallel with each other to the San Fernando Valley. At certain points along the syncline, as, for instance, 

at the head of Pico Canyon, there is some evidence that faulting 

has taken place immediately to the south, the strata south of the 

fault plane being downthrown and the plane itself inclined at an 

angle of 50° to 70°. The evidence, however, was not followed up,
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. IX

A. OVERTURN IN VAQUEROS FORMATION, WEST SIDE OF P1CO CANYON, LOS 

ANGELES COUNTY.

B. PICO ANTICLINE, PICO CANYON, LOS ANGELES COUNTY.
SANTA CLARA VALLEY: PICO FIELDS. 91

and on the map (PL I) the syncline is in the main given as unbroken. 

The similarity between this fold and the Tapo anticline is worthy of 

remark. In each case there is a principal anticlinal fold, with a parallel syncline on the south, and faults and a highly crushed zone in 

one instance and perhaps also in the other still farther south. The 

position of the Pico anticline is en echelon with that of the Tapo to 

the west and also with that of the Elsmere to the east, all being 

somewhat diagonal in trend to the general direction assumed by the 

ranges.

The strata involved in the folds described above and underlying 

the adjacent regions include a heavy deposit, presumably of lake 

beds, in the low hills about the junction of Santa Clara River and 

its tributary, Newhall Creek; conglomerate, sandstone, and clay of 

the Fernando, of a horizon possibly somewhat younger than that of 

the Fernando beds that lie immediately east of the mouth of Piru 

Creek; and a succession of brown and chocolate-colored shale, comparatively thin interbedded sandstone, and local conglomerate, 

which will doubtless prove to be of lower Miocene (Vaqueros) age, 

of the same horizon as the beds of similar nature in the region of 

Torrey and Tapo canyons and in the northern front of Oak Ridge 

farther west. The assumption that the beds last mentioned are 

lower Miocene is, in the absence of fossils, based on their lithologic 

resemblance to those of other localities in which determinative forms 

occur, on the presence of organic siliceous shale here and there in the 

beds of chocolate-brown color and of more earthy character, and on 

the occurrence of concretionary bodies, round to elliptical, in the 

sandstone of the formation. The shale and sandstone regarded as 

Vaqueros are confined to the heart of the anticline and to the regions 

adjacent which are affected by the subordinate folds in connection 

therewith. They occupy the entire front of the range to their line 

of union with the Fernando beds near the base.

The Fernando formation displays marked regularity of strike and 

dip, and from any of the high points within the range may be seen 

arching about the foothills from the vicinity of Newhall across Pico 

Canyon to the mouth of Salt Creek, bending in its trend from N. 

50° W. to N. 75° W. A conspicuous feature of this formation is a 

great mass of bluish-gray clay that occurs a short distance above its 

base. It is particularly strong of outcrop in Road Gulch, perhaps 

on account of the gentle dip and wide erosion of this portion of the 

formation. The conglomerate which overlies this clay is heavily 

developed in beds from 50 to 300 feet thick.

The line between the Fernando formation and the beds regarded 

as Vaqueros is placed at the horizon of the uppermost brown or 

chocolate-colored shale. Conglomerate extends below this horizon, 

but not of the importance attained by those above. The manner
92 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

of its occurrence is somewhat perplexing, for it is interspersed among 

the chocolate-colored shale and does not show the individuality of 

the two zones of heavy conglomerate that lie at the base and summit 

of this formation in the region of Wiley and other canyons to the 

west. Unconformity between the two formations probably exists, 

although angular discrepancies were not detected at any point in 

the Pico region. The absence, however, of the heavy mass of siliceous shale between the Vaqueros and the Fernando beds along the 

lower northern slopes of the Santa Susana Mountains is noteworthy. 

South of the Oak Ridge-South Mountain anticline, in the lofty upper 

escarpments, this shale attains a thickness of 300 to 500 feet and 

separates the Vaqueros from the Fernando conglomerate and sandstone on the southern slopes of the mountains. The absence of the 

siliceous shale in one locality and its presence in the other, notwithstanding the short interval between the two, suggest unconformity between the Fernando and the underlying beds. Moreover, 

there are several areas over which distinct unconformity is observable.

Main n'dge

Peak east of 

Fryer's

FIG. 10. Section through Fryers Peak east of Fryer's ranch. Dots represent sandstone; fine lines,

shale; a, b, beds of shale.

The Pico anticline has proved one of the most productive folds in 

the Santa Clara Valley. It exhibits marked regularity; the fold 

maintains a comparatively uniform elevation from west to east for 

nearly its entire length, and the beds involved are of uniform texture 

and uniformly disposed with reference to one another and to the 

axis of the fold. The inference seems natural, therefore, that such 

conditions would be favorable to the extended field that has. been 

.developed.

The northern slope of the Santa Susana Mountains presents considerable regularity in the succession of beds from the crest nearly 

to the line of the Pico oil field, but to the south.of the crest, especially 

in the area opposite the Salt Creek drainage and the more easterly 

tributaries of the Tapo, there is a conspicuous crumpling in a zone 

half a mile wide, trending N. 70° W. The most severe crushing is to 

be seen immediately beneath the summit of the range, where in the
SANTA CLARA VA.LLEY : PICO FIELDS. 93

chocolate-colored shale and its accompanying sandstone of the Vaqueros -two or tliree anticlines, with their intervening synclines, occur 

in close succession; indeed, surface conditions suggest faulting similar 

to that shown in fig. 10. Within this zone or possibly slightly south 

of it is a dry well, the depth of which is unknown to the writer. The 

linear extent of the zone is unknown, but disturbance of the strata 

may be detected as far as the divide between the Simi and San Fernando valleys, and this series of fractures may prove continuous 

with the great fault suggested by the Whitney survey as south of at 

least the eastern half of the Santa Susana Range.

It is very evident that there is a pronounced unconformity between the Fernando conglomerate, sandstone, and clay and the older 

formations of Miocene, Eocene, and Cretaceous age south of the Santa 

Susana Mountains. The line dividing the Fernando from the older 

formations is, however, indicated only in a general way on the map, 

for the region was not studied with a view to geologic detail, being 

somewhat beyond the areas of developed oil fields.

PRODUCTIVE FIELDS OF THE PICO DISTRICT.

The productive fields of tne Santa Susana Mountains, enumerated 

from west to east, include those of Pico, Dewitt, Towsley, Wiley, 

Rice, and East canyons, all on the northern slope. With the exception of those in Dewitt Canyon, which are apparently on a secondary 

crumple, all are ranged along the main Pico anticline, some to the 

north, others to the south of the axis. The anticline apparently 

maintains a uniform elevation except at the extremities, where it 

pitches east and west, respectively. This uniformity of level may 

account for the fact that the anticline has been found productive for 

so large a proportion of its length. This is in marked contrast to 

the development along the Oak Ridge anticline, the axis of which is 

decidedly undulating and which has been proved productive only 

at its point of maximum elevation opposite the town of Bardsdale. 

Doubtless many other factors enter into the explanation of the relative productiveness of the two anticlines, but the conditions above 

mentioned are to be considered in any attempt to account for it.

Only a single formation, the Vaqueros, is present in the productive 

oil fields of the Santa Susana Mountains. Its correlation is based 

on lithologic similarity to recognized lower Miocene beds of other 

localities, no fossils having yet been found in it in this district. The 

strata include a large proportion of brown argillaceous and arenaceous shale, much interbedded sandstone, and considerable conglomerate. Brown and white bands, a feature characteristic of this 

formation from Chaffee Canyon westward, are far .less conspicuous 

in front of the Santa Susana Mountains, but conglomerate has a 

much greater development. As elsewhere, the shale includes at
94 OIL DISTRICTS OF SOUTHERN CALIFOBNIA.

short intervals thin strata of a siliceous nature and limestones that 

are more or less concretionary. The sandstones and sandy shales 

are also concretionary, and here and there a bed may be found which 

bears a striking resemblance, except for thickness, to the lower Modelo 

sandstone -north of the Santa Clara. The entire series has been more 

or less impregnated with bitumen, to which is probably due, in a 

large degree at least, its brown color. Except for local variation in 

the materials composing these beds, there is considerable regularity 

in their appearance as a whole, and the general succession is comparatively well maintained from one end of the region to the other. 

The local irregularities in composition, however, render it next to 

impossible to correlate the logs of wells a mile or more apart along 

the anticline. The dips are steep in many places, yet the crushing 

that is found in the region of Tapo and Torrey canyons is here 

wanting. *

OIL WELLS.

PICO CANYON WELLS.

The wells of Pico Canyon, which belong to the Pacific Coast Oil 

Company, are located not far from the west end of the Pico anticline, 

which terminates in the divide between Pico and Salt canyons. In 

the western half of the productive territory the axis of the fold has 

a distinct pitch to the west. Between 40 and 50 wells have been 

drilled in the field, some more productive than others, but nearly all 

yielding at least a few barrels of oil. With the exception of three at 

the upper forks of the canyon, all are on the northern limb of the 

anticline, not far distant from the axis. They are sunk not only in 

the canyon, but even on the'summits of the sharp knobs on either 

side of the gorge, the lowest and highest having a difference in elevation of 700 feet. The depth of the wells varies from 600 to 3,000 

feet. The logs were not ascessible to the writer, but the superintendent stated that no two holes showed the same succession of beds 

and that it was impossible to distinguish horizons as between wells. 

It is also stated that there is no clearly defined horizon at which oil 

occurs. As an instance, it is reported that of three wells nearly in 

line of strike, in beds of approximately the same amount of dip, and 

within a distance of but a few hundred feet, one afforded a certain 

oil at a depth of 1,600 feet, another a like oil at 1,200 feet, while the 

third, midway between the other two, was 1,900 feet deep and 

showed not a trace of oil. The superintendent under whose direction the wells had been drilled suggests the possibility that the oil 

passes from one horizon to another; this is not contrary to one or 

two observed occurrences, where beds impregnated with asphalt, 

originally petroleum, have been exposed. Of the many wells in this 

canyon the three south of the anticlinal axis are said not to be so
SANTA CLARA VALLEY: PICO FIELDS. 05

productive as those on the north, yet other factors may enter into 

this difference besides the mere positions of the wells. The general 

strike of the beds in the Pico field is about N. 55°-60° W. The dip 

north of the axis is about 55°, south of the axis 65°, though locally 

on each side it is 80°.

The average production of the wells at the present time is from 12 to 

25 barrels, although a few yield but 1 to 5 barrels. At the start some 

wells produced as high as 80 barrels, gradually dropping to the steady 

average maintained at the present day. The oil is green in color and 

its gravity 38° to 40° B. It occurs in sandstone, conglomerate, and 

shale, but apparently the texture of the bed is without influence on 

the oil. The age of this field, or the life of its oldest well, is about 

twenty-eight years.

DE W.ITT CANYON WELLS.

The wells of Dewitt Canyon are but three in number. It is reported that although they afford a slight amount of oil, the yield has 

never warranted operating. The well in the main canyon is located 

immediately south of "the axis of what is apparently a secondary fold 

thrown off to the north from the Pico anticline, midway between the 

Pico field and Dewitt Canyon. The other two wells were not visited 

by the writer, but probably lie somewhat to the north of the axis of 

this fold. The formation penetrated is principally the brown shale 

of the Vaqueros. The strike of the axis of the branch anticline is 

more nearly east and west than that of the main fold to the south. 

The beds south of the axis dip 40°, and those north of the axis 45° 

to overturned. The well in the main canyon is said to have produced 1 barrel of black oil a day, of a gravity of 20° B.

The subordinate anticline on which the Dewitt wells are located 

may be traced eastward as far as Wiley Canyon, but no further 

developments have taken place along it, and its appearance is in many 

places that of a mere crumple rather than of a well-formed fold. 

TOWSLEY CANYON WELLS.

In Towsley Canyon 6 or 7 wells have been drilled, all but 1 being 

near the axis of the Pico anticline. Three of the wells lie on the 

southern slope of the fold, the remainder on the northern slope. The 

strike of the beds is about N. 55° W. The northerly dip varies from 

25° to 65°, the southerly from 25° to vertical and overturned. The 

wells near the axis of the fold yield oil, water, and gas, the 3 north of 

the axis producing somewhat in excess of those south of it; all, however, are small. One well, at a distance of about half a mile south of 

the axis, is dry. Seepages of oil occur on the axis on both sides of the 

canyon. The strata in the heart of the anticline are brown shale 

-interbedded with siliceous shale and carrying hard yellow silico-calcareous beds more or less in the form of concretions. The gravity of 

the oil in this canyon is 26° B.
96 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

WILEY CANYON WELLS.

The wells of Wiley Canyon lie 200 or 300 feet south of the anticlinal axis. The Pacific Coast Oil Company drilled 13 wells in this 

canyon ranging from 600 to 1,626 feet in depth". Only 3, however, 

were found productive. The gravity of the oil is reported to be 30° B. 

At the time of the writer's visit to the locality the Wiley Canyon wells 

were idle.

RICE CANYON WELLS.

The producing wells of Rice Canyon include 2 of the. Pacific Coast 

Oil Company and 6 belonging to W. P. Rice. The Pacific Coast wells 

are in the bottom of the canyon, the Rice wells on the hill to the east. 

All are in brown shale bearing gray-yellow concretions of limestone. 

These wells lie on the south limb of the Pico anticline, comparatively 

near the axis. The dip on this side is 22° to 35°, on the north side 

25° to 75°. The crest of the anticline over an area 100 yards wide is 

considerably crumpled. The Rice wells vary in depth from 825 to 

1,600 feet. They yield gas, oil, and water. In No. 5, the deepest 

well at the time of the writer's visit, oil sands are reported at 800 and 

1,550 feet. The yield of the wells is small.

Farther up Rice Canyon, one-half mile above the sharp turn from 

east to north, is the Newhall well, 1,500 feet deep, but without oil. 

The strike of the beds is here N. 65° W. and the dip 60° S. The well 

is only about 100 feet north of the axis of the Pico syncline, which 

lies parallel with the anticline at a distance of half a mile. The 

strata penetrated by this well are sandstone, with some shale. The 

horizon is considerably higher than that of the Rice wells.

EAST CANYON WELLS.

There are only a few wells in East Canyon, and but little information is available concerning them. Of the two observed by the 

writer, one is about 400 feet south of the axis of the Pico anticline, in 

heavy brown shale; the other about an equal distance north, in strata 

much the same. The southern well is known as the Bradshaw and is 

said to have yielded a small amount of black oil. The one north of 

the axis is reported dry.

' ELSMERE FIELD. 

LOCATION.

The Elsmere field comprises that portion of the Newhall district 

lying east of Newhall Creek and extending as far east as Los Pinetos 

Canyon. The productive territory is confined to the northwest end 

of the San Gabriel Range, which terminates at Fernando Pass and 

Newhall Creek.

a- Watts, W. L., Oil and gas yielding formations of California: Bull. California State Mining Bureau 

No. 19,1900, p. 69.
SANTA CLARA VALLEY: ELSMEKE FIELD. 97 

GEOLOGY AND STRUCTURE.

At Fernando Pass, the low point between the Santa Susana and 

San Gabriel mountains, there is a break in geologic continuity. The 

Elsmere anticline, described below, forms another step in the en echelon development exhibited by the Torrey, Tapo, and Pico anticlines 

farther west. The Elsmere fold, however, is hardly more than a 

secondary flexure of gentle curvature on the western flank of the San 

Gabriel Range.

The formations involved in the Elsmere field include a vast body of 

granite and schist, probably of Jurassic age; chocolate-colored shale, 

sandstone, and minor beds of conglomerate bearing characteristic 

fossils of the Vaqueros formation; the Fernando (Pliocene) conglomerate, sandstone, and clay; and certain Pleistocene gravel, sand, 

and clay, already mentioned in the description of the Pico anticline, 

that occupy what appears to have been an old lake basin coincident 

with the present valley of the Santa Clara in the vicinity of Newhall 

and Saugus.

The granite and schist occupy the heart of the San Gabriel Range; 

the other formations, except the lake beds, encircle its west end. 

Although the San Gabriel Range is probably the result of faulting 

there is in the encircling Tertiary rocks at least one anticlinal flexure, 

the Elsmere. This anticline has been developed in somewhat unsymmetrical form, the axis lying well toward the southern side of the fold. 

(See PI. IV, sec. M"-M-M'.) The elevation of the strata north of the 

axis is maintained by minor flexures, until at a distance of a mile or 

more the beds drop beneath the level of the lower hills and pass to the 

east, with a N. 7£° E. strike and a dip of 25°-30° N. The syncline 

separating the Elsmere anticline from the Pico fold is suggested in the 

curves of the strata in the creek southwest of Newhall and in one or 

two minor crumples in the Fernando formation higher in the hills. 

In the Vaqueros beds on the Santa Susana side there are two folds 

having a general trend of N. 60°-70° W. One is the eastern terminus 

of the Pico anticline and the other of the syncline to the south. These 

folds do not appear east of the Southern Pacific Railroad, their trend 

carrying them at this point into the San Fernando Valley, beneath the 

lev.el of which the anticline sinks. The Fernando formation, lying 

between the two bodies of Vaqueros east of the railroad, maintains a 

southwesterly to southerly dip, except immediately north of the axis 

of the Elsmere anticline, in proximity to the more northerly body of 

Vaqueros. The relations of the Fernando to the underlying strata are 

extremely irregular and the details of the unconformity have not been 

worked out. About the northern base of the San Gabriel Range, 

however, east of the railroad, this unconformity is readily discernible,
98 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

It is particularly marked in the varying beds upon which the Fernando rocks rest, showing that the earlier beds of this formation were 

deposited across the upturned edges of the Vaqueros.

The source of oil in the Elsmere anticline is in part, doubtless, from 

the sandstone and conglomerate immediately overlying the Vaqueros, 

but the numerous wells in Elsmere Canyon draw their supplies from 

Vaqueros strata.

OIL WELLS.

The Elsmere oil field is developed in the broad sweep of the strata 

about the west end of the Elsmere anticline. The companies operating, named in order from south to north, include the Enterprise, 

Zenith, Eureka Crude, Pearl, Santa Ana, 'and Pacific Coast. The 

Pacific Coast wells are confined chiefly to the slopes and bottom of 

Elsmere Canyon, although a few are ranged along the crest and western face of Elsmere Ridge. The Santa Ana Company has three wells 

high up on the north point of this ridge, while the wells of the other 

companies are ranged along a tributary of Newhall Creek, west of 

Elsmere Ridge, in proximity to the Los Angeles wagon road. Roughly, 

the wells are ranged concentrically about the anticline, the Enterprise, Pearl, and Zenith lying farthest out and to the west, the wells of 

Elsmere Ridge in a circle somewhat within these, and those of the 

Pacific Coast Oil Company in Elsmere Canyon nearest the heart of 

the fold. -In addition to the above Nettleton & Kellerman have a 

group of three wells a little farther north and the New Century and 

Freeman & Nelson oil companies a few wells,in Placerita Canyon, 5 

miles east of Newhall. The well of the California Oil Company, high 

up on the slopes of the San Gabriel Range, is said to penetrate a few 

feet of still older beds of the Vaqueros and then to pass into granite.

ENTERPRISE, PEARL, AND ZENITH WELLS.

The Enterprise well and one of the Pearl Oil Company near by; 

both but a few feet south of the axis of the anticline, are said to be 

between 800 and 1,000 feet deep and to have failed to find oil. The 

Zenith Company, one-half mile north, has two wells which penetrate 

yellow sand of considerable stability; running sand, soft, blue, and 

bearing cobbles; blue shale or adobe, as it is called by the drillers; 

and at the bottom of the wells, 600 to 630 feet below the surface, other 

sands, together with a few " hard shells." The supply is derived from 

the lowermost sands of these wells, beneath about 230 to 270 feet of 

"adobe." The production of the wells was at first 15 barrels per day, 

but is now 10 barrels. The gravity of the oil is-19° B.

Two other wells of the Pearl Oil Company, adjacent to the Zenith 

wells, have a depth of 665 and 720 feet. The deeper is as yet unfinished. Adobe is reported in it from 370 feet down. In the other
SANTA CLARA VALLEY: ELSMEKE FIELD. 99

well an oil sand was encountered at 570 feet, but not until 600 feet 

was reached did the yield become sufficient to justify pumping. In 

this well sand and cobbles are reported nearly all the way down, 

although it is probable that in the lower portion some adobe or clay 

was encountered. It is almost certain that the adobe reported in this 

locality is but a clay body of considerable extent held in the sandstone 

and conglomerate. It may, however, correspond in a measure to the 

great body of blue clay observed in Pico Canyon between the lowest 

conglomerate of the Fernando formation and those next higher. 

Other wells were in process of drilling by these companies, but were 

unfinished at the time of the writer's visit.

ELSMERE RIDGE WELLS.

The depth of the wells on the crest of Elsmere Ridge (see PI.VII, B} 

is said to be approximately 1,000 feet, but the information is somewhat indefinite. They are sunk in heavy sandstone and conglomerate 

which strike with the crest of the ridge, north and south, and dip 

25° W. The source'of the oil is probably near the base of the Fernando beds, and the production is not heavy. The gravity of the oil 

is reported as about 14° B.

ELSMERE CANYON WELLS.

Of the 15 wells in Elsmere Canyon, which belong to the Pacific 

Coast Oil Company, but little was learned. Seven were said to be productive, yielding from 7 to 75 barrels a day. They are reported to 

range from 400 to nearly 1,000 feet in depth. Soon after the writer's 

visit (1902) the company abandoned its property in this field.

NETTLETON & KELLERMAN, WELLS.

In the shallow gulch immediately north of Elsmere Canyon, perhaps a mile distant from the Elsmere wells, is a group of three wells 

owned by Nettleton & Kellerman. Two of these are unproductive, 

the other yields 10 barrels per day, deriving its supply from a depth of 

1,100 feet. The gravity of the oil is 20° B. The strike of the measures is here N. 70° E. and the dip 23° N.. The source of the oil is 

probably one of the lower members of the Fernando formation.

WELL SOUTH OF RIDGE CREST.

On the southern slope of the San Gabriel Range, about a mile eastsoutheast of Fernando Pass, is a well drilled near a brea deposit. It 

is abandoned and its history was not investigated. It is located on 

the outcrop of the Fernando formation, but if any considerable depth, 

was reached it may have passed into Vaqueros beds. -
100 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

PLACERITA CANYON WELLS.

Perhaps the most remarkable of all the oil fields of California is an 

area of insignificant size in Placerita Canyon, 5 miles east of Newhall. 

The oil here is almost a naphtha, and its gravity is said to be above 50°. 

The yield is very slight. The remarkable feature in connection with 

the oil is its occurrence in crystalline schist which overlies the San 

Gabriel granite and which is in turn overlain at no great distance from 

the wells by rocks that are believed to be of the Fernando formation. 

Oil was discovered in shafting for gold.

The schist in which the oil occurs is micaceous and granitic, con-r 

spicuously banded, and greatly contorted. It strikes approximately 

N. 70'° W. and dips 50°-SO° N. The accompanying diagram (fig. 11) 

indicates the position of the wells. There are six in all, the three on 

the north belonging to the New Century Company and those on the 

south to Freeman & Nelson. The New Century wells are nearer the

Fernando sandstone and conglomerate, which approach 

within a few feet. It is said 

that one of these wells spouted high and that another 

barely flowed. The deepest 

well of the six is the southernmost of the Freeman & Nelson group, which attained a 

depth of 1,030 feet. Oil is 

reported in this well at 410, 

613, and 682 feet. It is said 

to yield 5 or 6 barrels per 

day, with 30 or 40 barrels of 

water to each barrel of oil. 

In a tributary of Placerita Canyon, three-fourths of a mile east of 

the wells described above and in the same schist, is the Pioneer well, 

1,100 feet deep. It struck oil, but the yield could not be learned. 

The granite lies about three-fourths of a mile south of this well.

The presence of oil under conditions similar to those that exist here 

is perhaps unknown in any other part of the world. It occurs from 

400 to 1,000 feet beneath the surface in a steeply dipping and closetextured crystalline schist. That a reservoir, even though small, 

exists in such rocks must be due, it would seem, to the fracturing of 

the schist, the natural result of the severe contortion to whicn it has 

been subjected. If the oil originated in the schist, or rather in the 

sediments from which the schist was metamorphosed, it is beyond 

comprehension that it should have remained in them under the tre^ 

mendous pressure and heat to which the strata have unquestionably

FIG. 11. Sketch map showing location of Placerita 

Canyon wells, 5.miles east of Newhall. Heavy dots, 

wells. Figures indicate numbers and depths of wells.
SANTA CLAEA VALLEY: ELSMERE FIELD. 1Q1

been subjected. Indeed, it seems to be an impossibility that such 

can be the history of its development. Moreover, the gravity of the 

oil, between 50° and 60° B., is equally enigmatical. Even if it was 

originally a high-gravity oil, the lighter hydrocarbons would have been 

the first to be given off in 'the heat, pressure, and fracturing to which 

the rocks have been subjected, and if anything remained it should 

have been the asphaltic or paraffin residue. It may be that the oil is 

of later origin or, in any event, that it was for a time stored in another 

reservoir, perhaps of Vaqueros age, possibly even of Fernando age. It 

is possible that from such a reservoir the light oil, already from some 

cause separated from the heavy oil, may have found its way between 

the two formations and penetrated the crystalline rocks through one 

of their fractured zones.

Bull. 309 07 8
THE PUENTE HILLS OIL DISTRICT, SOUTHERN 

CALIFORNIA.

By GEORGE HOMANS ELDRIDGE.

INTRODUCTION.

In the following report it is proposed to describe briefly the geology 

. and structure of the Puente Hills, especial attention being given to 

those features which appear to have a bearing on the occurrence of 

petroleum in the different fields of the district. The reader is referred 

to Mr. Arnold's report on the Los Angeles district (pp. 138-142) for 

information concerning the previous knowledge of the region and for 

a bibliography of publications relating to it.

ACKNOWLEDGMENTS.

Acknowledgments are due to the various oil companies and their 

managers in the different fields for assistance in various ways and for 

information given by them during the course of the work. Thanks 

are due more particularly to Mr. Fred T. Perris, manager of the Santa 

Fe Railway oil properties; to Mr. E. A. Bacon, of the Murphy Oil 

Company; to Messrs. Graham and Loftus, of the Graham-Loftus Oil 

Company; to Mr. R. N. Bulla, of the Central Oil Companyr and to 

Mr. Dan Murphy, of the Brea Canyon Oil Company. Uniform courtesy has b.een shown by those in control of the different properties in 

this district, all, without an exception, furnishing any information 

requested.

LOCATION AND TOPOGRAPHY.

The Puente Hills, along the southern face of which has been developed one of California's most productive oil territories, are situated in 

-the southwest corner of the State, beginning at a point about 12 

miles slightly south of east of Los Angeles and extending in a general 

east-southeasterly direction for 22 miles to Santa Ana River. They 

cover an area, roughly, of about 140 square miles. The western 

and northern parts of the hills lie in Los Angeles County; the southeastern part is divided between San Bernardino County on the north 

and Orange County on the south. They are situated but 35 miles 

from San Pedro, the principal deep-water harbor of southern California,

102
U.S. GEOLOGICAL. SURVEY 

CHARLES D.WALCOTT, DIRECTOR BULLETIN NO.309 PL.X

U8°00'

II8°00'

LEGEND

Saruds tone

Axes of folds 

Oil-wells

u

Strike and dip

Axis of syncliiue

t

Axis of anticline

Topography by U S Geological Survey, GEOLOGIC MAP OF THE OIL FIELDS OF THE PUKNTE HILLS,CALIFORNIA

Scale 62&OO

Geology by George H.EIdridge-i9O2

miles

5 liilometers

Contour mterral 20 feet

J)atmtL i&ttiecav sea, level

19O6.
PUENTE HILLS: PUENTE FOEMATION. 103

The Puente Hills are the northwestern extension of the Santa Ana 

Mountains, from which, however, they are now separated by the deep 

canyon of Santa Ana River, with a fault, perhaps, as an interruption 

to the present continuity of structure. The general trend of the hills 

is. west-northwest. Their highest point, 1,780 feet, is San Juan Hill, 

on the boundary line between San Bernardino and Orange counties. 

In the eastern half of the hills numerous peaks reach elevations between 

1,200 and 1,400 feet, but in the western half this altitude is exceptional. The base of the hills lies about 400 feet above sea level. For 

3 or 4 miles to the south an altitude of 200 or 300 feet is maintained, 

the southern edge of this area being defined by a low ridge that lies 

parallel with the hills from the region of Placentia to a point opposite 

Whittier. South'of this the elevation drops to less than 150 feet, 

decreasing gradually to the sea. 

The region of the Puente Hills is diy, all the streams being intermittent. The canyons are deeply cut and in places present considerable ruggedness of aspect. Nearly all are the result of erosion, 

although the loci of some of the erosion valleys were doubtless determined by the folding to which the strata had been subjected. Narrow, perpendicular-sided channels characterize the bottoms of many 

of the canyons, especially those cutting through shale. In many 

places, however, the higher slopes are gentle and the hill summits 

rounded and grassed.

GJECXLOGY. 

FORMATIONS.**

The formations involved in the geology of the Puente Hills include 

the Puente formation, largely sandstone and shale, of Miocene age 

and the equivalent of at least a part of the Modelo formation, and 

possibly including some of the Vaqueros; some diabase post-Puente, 

probably contemporaneous with similar rocks found throughout the 

Coast Range as far north as San Francisco; clay, sandstone, and 

conglomerate of the Fernando formation, largely Pliocene in age; and 

superficial Pleistocene deposits of sand and gravel. (See PI. X.) 

The Puente formation has been divided on lithologic grounds into 

a lower shale, a sandstone, and an upper shale.

LOWER PUENTE SHALE.6

The lowest rocks exposed in the Puente Hills, which will be called 

the lower Puente shale or simply lower shale, embrace at least 2,000 

feet of shale, in the main earthy, but with minor members of a silio A table giving the formations of the Santa Clara Valley, Los Angeles, and Puente Hills districts, 

together with their probable correlatives of the standard Tertiary formations of California, is given 

on p. 143.

6 It was not the intention of the authors to apply specific names to the divisions of the Puente, 

but to treat them as unnamed parts of that formation.
104 OIL D-ISTKICTS OF SOUTHERN" CALI'JTOKNIA.

ceous nature, the whole gray or brown from the presence of iron and 

bitumen. Thin, frne-grained sandstones are interbedded with the 

shale from top to bottom and lenticles of gray limestone weathering 

yellow also occur. All in all, the formation bears close resemblance 

to the Monterey and certain portions of the Modelo. The only evidenSfe of life thus far discovered consists of foraminifera and diatoms, 

so common in the Miocene of the Pacific coast. These occur in both 

shale and limestone. The shale is exposed in the heart of the hills 

with varying prominence; its outcrop is especially strong from Brea 

Canyon westward and in the southeastern portion of the hills. To 

judge by the sequence of beds in other parts^ of southern California, 

this shale is probably underlain by a mass of coarse sandstone.

PUENTE SANDSTONE.

Overlying the shale is a moderately coarse gray to yellow heavybedded sandstone, separated by minor bands of organic siliceous shale. 

Spherical and lenticular concretions, consisting of the same material 

as the mass of the rock, characterize the sandstone. The lower portion of the sandstone is more .thinly bedded than the upper, and the 

intercalated shale is more earthy, suggesting a transition to the underlying member. This feature is especially conspicuous along lower 

Soquel Canyon. The thickness of the sandstone varies from perhaps 

less than 300 feet in the western portion of the hills to possibly over 

1,000 feet in the eastern portion, where it lies in a gently undulating 

position, and its areal extent is veiy great. The sandstone is wanting 

in outcrop along the southern face of the hills opposite the wells of 

the Puente Oil Company.

UPPER PUENTE SHALE.

Overlying the Puente sandstone is a variable thickness of earthy, 

siliceous,- and chalk-like shale, with a few beds of fine yellow ferruginous sandstone and minor quartzo-calcareous concretions. This portion of the formation will be called the upper Puente shale, or upper 

sliale. The thickness is uncertain, but in the region of the Olinda 

field it appears to be considerably less than it is believed to be in 

the western portion of the hills. Nowhere, perhaps, is it more than 

300 or 400 feet in outcrop. However, the overlying formation rests 

upon it unconformably, and for this reason it is impossible to estimate 

its full original thickness. In doubtful structural positions only has it 

been suspected of having a development of over 100 feet. The most 

important instance of this kind is on the eastern border of the Whittier 

field, where the crest of the hills shows the following section from
PUENTE HILLS: PUENTE FORMATION. 105

north to south: In the axis, shale that is believed to be the lower division of the Puente; at the southern edge of the crest, sandstone that is 

identified as Puente, 200 or 300 feet in all; and on the southern face of 

the ridge, other shale, also of the Monterey type, bearing the fossil Pecten pedroanus, -and succeeded across a fault plane by the next younger 

.(Fernando) formation. The uppermost two beds have a northerly 

dip; the inclination of the Puente sandstone is exceedingly steep, with 

a dip here north and there south, and a consequent uncertainty as to 

which of these directions is the normal. The shale in the heart of the 

hills is crushed and crumpled. Were it not for this extensive crumpling arid the attendant faulting the sequence given above might be 

regarded as normal; yet an alternative is possible, namely, that the 

suspected uppermost shale, with its northerly dip, occupying the 

southern face of the ridge adjacent to the fault line, may be instead 

the lower member and pass beneath the highly inclined Puente sandstone at the crest of the ridge, the two together being faulted down 

against the lower shale farther north, or that it may, by a sharp reversal of its dip, again return to the surface in a compressed and broken 

synclinal fold.

CORRELATION OF THE PUENTE FORMATION WITH THE

MONTEREY.

The resemblance of both lower and upper divisions of shale, if such 

there be, to the Monterey, as it is known in other parts of the 

Coast Range, may warrant their correlation, the Puente sandstone to 

be regarded as an intercalated member. Yet, before finally accepting 

this view, it is well to recall the marked lithologic similarity of portions 

of the lower division of the Puente formation to certain strata in the 

Santa Clara Valley and elsewhere in the Coast Range that have been 

determined by their fossils to be lower Miocene and possibly Oligocene; lower than the Monterey. From geologic conditions to the 

south of the Puente Hills in the Santa Ana Range, however, the 

writer is inclined to consider the entire succession of beds described 

above as the local equivalent of the Monterey. The only fossil thus 

far obtained from the Puente shales is Pecten pedroanus Trask (see PI. 

XXXVI, figs. 5 and 6), a form which is found both in the Miocene and 

lower Pliocene. A nearly related form, Pecten peckliami. Gabb (PI. 

XXXI, fig. 3), is a characteristic species of the Monterey (middle Miocene) .
106 OIL DISTRICTS OF SOUTHERN CALIFORNIA. 

POST-PUENTE DIABASE.

A dike of diabase nearly a mile long and varying in width up to an 

eighth of a mile breaks through the Puente sandstone and shale along 

the southern slope of the hills north of the mouth of Brea Canyon. 

The exposed portions of the rock are so much weathered that good 

specimens could not be obtained. The altered material is grayish in 

color and shows the light-colored, lath-shaped feldspar crystals very 

distinctly in the specimens examined. The outcrop of this rock in the 

face of the ridge north of the road connecting the Puente and Brea 

Canyon fields has the peculiar irregular contour which enables one to 

distinguish it at a glance from the adjacent sedimentaries. Farther 

east the weathering of the diabase has stained the soil a peculiar reddish-brown color characteristic of the diabase areas throughout the 

Coast Range. The age of this diabase is approximately the same as 

that of similar diabase found in the Santa Monica Mountains in a like 

stratigraphic position that is, it is post-Puente and pre-Fernando 

and belongs in the upper Miocene of the time scale.

FERNANDO FORMATION.

The youngest of the Tertiary formations in the Puente Hills is a 

succession of gray to yellow quartzose and granitic conglomerate and 

sandstone, together with interbedded arenaceous shale and clay, in all 

at least 1,500 or 2,000 feet. Occasionally.a trace of eruptive debris, 

derived perhaps from the ranges to the north, is found with the other 

constituents, and locally a concretionary tendency may be observed. 

At one or two points, also notably on the crest of Brea Ridge south 

of the Union Oil Company's wells and on the main ridge north of the 

wells of this company in La Habra Canyon the formation appears to 

carry a few inclusions of siliceous shale and calcareous concretions. 

The conglomerate, sandstone, and clay are fossiliferous, the forms indicating an identity of the beds with the Fernando of the Santa Clara 

Valley district. A feature characteristic of this formation is the 

ready disintegration of its sandy shale, which under heavy traffic 

becomes an extremely annoying dust. This formation flanks the 

Puente Hills on the north, south, and west sides. It also covers a 

large area in the Coyote Hills, 3 miles south of La Habra Canyon, and 

here some exposures of its sandstone show a deep rusty or crimson 

color.

The following fossils, some of which are characteristic of this horizon, have been found in the Fernando beds, mostly in the vicinity of 

Olinda and Brea Canyon (see PI. XXXIV to XLI):
HJENTE HILLS: FERNANDO FORMATION. 107

Fossils from the Fernando beds of the Puente Hills.

[Species marked with an asterisk (*) are still living; those with a dagger (f) are supposed to be characteristic of this horizon.]

GASTEROPODA (UNIVALVES). . '

* Astyris (cl) gausapata Gould.

*Bulla (cf.) punctulata A. Adams.

*Calliostoma (cf.) costatum Martyn. 

. jCancellaria (sp. like San Diego well form).

*Conus (cf.) californicus Conrad.

*Crepidula (cf.) rugosa Nuttall.

*Dentalium neohexagonum Sharp and Pilsbry. 

Dentalium (n. sp. like Miocene form).

*Fissuridea murina Carpenter (PI. XL, figs. 3, 3a). 

Fusus cf. barbarensis Trask.

*Nassa fossata Gould.

*Nassa perpinguis Hinds. . 

*Neverita recluziana Petit (PL XXXVIII, fig. 6).

fPriene oregonensis Redfield, var. angelensis Arnold (PI. XL, fig. 11). 

fTrochita costellata Conrad (PL XXXII, fig. 3).

*Trophon multicostatus Carpenter.

*Turritella cooperi Carpenter (PL XLI, fig. 14).

PELECYPODA (BIVALVES).

*Arca multicostata Sowerby (?) (PL XXXVIII, fig. 1). 

Area trilineata Conrad (PL XXXVIII, figs. 3, 3a, 4}.

*Cardium (cf.) corbis Conrad.

*Cardium quadrigenarium Conrad, var. fernandoensis Arnold (PL XXXVIII, 

%. 2).

*Chione (cf.) fluctifraga Sowerby.

*Leda taphria Ball (PL XXXVIII, fig. 5).

*Metis (cf.) alta Conrad.

*Modiolus (cf.) rectus Conrad.

*j-Ostrea veatchii Gabb (PL XXXIX, fig. 1).

fPecten ashleyi Arnold (PL XXXIV, fig. 2).

. jPecten auburyi Arnold (PL XXXV, fig. 7).

*Pecten hastatus Sowerby.

fPecten nutteri Arnold.

fPecten oweni Arnold.

fPecten wattsi Arnold (PL XXXV, fig. 1).

*Phacoides acutilineatus Conrad.

*Phacoides californicus Conrad.

*Phacoides nuttallii Conrad.

*Phacoides richthofeni Gabb. 

Siliqua edentula Gabb.

*Solen sicarius Gould.

PLEISTOCENE.

Alluvial gravel, sand, and clay of one or more periods of deposition 

underlie the valleys adjacent to the Puente Hills.
108 OIL DISTRICTS OP SOUTHERN CALIFORNIASTRUCTURE. 

GENERAL STRUCTURAL RELATIONS OF THE FIELDS.

The structure of the Puente Hills is that of an anticline, contracted 

in the western part, expanded in the eastern. The main axis of the 

flexure is not everywhere easy of recognition, owing to the prominence 

of some of the nearly parallel secondary folds that exist throughout 

the length and breadth of the hills, but the line laid down on the map 

(in the eastern half of the hills the northern branch) approximately 

indicates the axis of the anticline. The general trend of the Puente 

fold is N. 65° W., varying but .a few degrees in either direction. 

Besides the main and parallel or slightly divergent secondary folds, 

there are several flexures, with a trend approximately northeast and 

southwest. These are particularly developed on the northern slope 

of the main anticline in the eastern half of the hills. The most important is the broad, gentle arch occupying the region of the forks of Brea 

Canyon, and to this is due, in considerable degree, the areal expansion 

of the Puente Hills in their eastern part. The eastern rim of the hills 

presents several complications of strike and dip, doubtless more or 

less connected in structure with the Santa Ana Range to the south. 

(See PL XI.)

The south side of the Puente Hills is devoid of folds other than those 

secondary to and parallel with the main anticline. On this side of 

the hills, however, the force which produced the anticline has most 

severely manifested itself, the folds being sharp and numerous and 

the strata badly crushed. Indeed, the data at hand suggest the possibility of a fault of considerable magnitude, extending from the 

extreme west end of the hills nearly or quite to Santa Ana River. The 

amount of throw is indeterminable, but local displacements of several 

hundred feet are indicated by the relation of the beds. The continuity of the fault, considered as a single fracture, is not established. 

On the contrary, it is probable that within the zone of maximum disturbance there are a number of fractures, more or less connected, it 

may be, yet throughout a-part of their course apparently distinct in 

fact, a zone of faults instead of a single uninterrupted break. The 

chief evidences of faulting are the continuity of a zone, of marked 

crumpling, the overturned and crushed condition of the beds at many 

points, variation in the succession of beds adjacent to the line of suspected fracture, and a divergence between trend of break and strike 

of strata, particularly well defined in the Whittier field. On the other 

hand, the line of possible fractures is at no point far distant from the 

contact between the Fernando and the Puente formations, and it is 

well known that throughout the Coast Range there is a conspicuous 

unconformity at this horizon. Without doubt the unconformity is
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XI

Fernando conglomerate, 

sandstone, and shale

_2 miles

Fernando conglomerate 

sandstone, and shale""

Fernando 

'conglomerate,

sandstone, 

and shale

2 miles

GEOLOGIC SECTIONS ACROSS THE OIL FIELDS OF PUENTE HILLS DISTRICT. 

A-B, C-D, Whittier field; E-F, Puente field; G-H, La Brea Canyon field; I-J, Olinda field.
PUENTE HILLS: STEUCTUBE. 109

present in this field, and it is probable, too, that the younger sediments, as has been found the case with their equivalents elsewhere, 

were laid down upon the already upturned and partially eroded beds 

of the older formation. This would account for many of the irregularities noted along the length of the disturbed belt, but the broken condition of the beds on either side of the line of suspected fracture and 

the steeply inclined, in many places overturned, dip of the Fernandp 

sediments in proximity thereto indicate a combined effect of faulting 

and unconformity for the zone in question. The conditions are almost 

a repetition of those in the McKittrick district, in the San Joaquin A^alley, along the eastern base of the Coast Range. The oil fields of the 

Puente Hills have been developed in the zone of sharp crumpling and 

in proximity both to the trace of the possible fault and to the line of 

unconformity; the important wells of the McKittrick district have 

been drilled along the fracture and adjacent to the unconformity there 

existing. A guide to development has been the numerous seepages 

that occur along the belt of severely.disturbed strata; but these have 

not always proved reliable indications of a large accumulation of oil.

COYOTE HILLS ANTICLINE.

The low east-west ridge known as the Coyote Hills, 3 or 4 miles 

south of the Puente Hills, is an anticline which flanks and is in a 

general way parallel with the Puente fold1 and was probably developed synchronously with it. The exposed strata in the west end of 

the Coyote Hills are the Fernando conglomerate and sandstone, but 

no data were obtained indicating how thick they are at this locality 

or at what depth the underlying Puente shale and sandstone lie. 

No seepages have been found in these hills, but toward their west 

end, 3 or 4 miles south of Whittier, is a large gas well. It is probable that oil also exists in the crest of this anticline, but at what 

depth and in what quantities only future development will show. 

Some of the most productive wells, however, are located in regions 

where the structure is similar to that of this ridge.

GEOLOGIC RELATIONS OF OIL-BEARING STRATA.

The distribution of the surrounding mountain masses and the position of the Puente Hills in relation thereto do not appea'r to have 

influenced the accumulation of oil. On the contrary, the significant 

factors appear to be the anticline, the sharply disturbed zone along 

its southern side, the fault that seems to be located within this zone, 

and the unconformity between the Fernando and the Puente formations. Finally, all the foregoing conditions would be unavailing liad 

not the formation of petroleum taken place somewhere within the 

succession of beds in the close vicinity of the hills.
110 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

All the sedimentary formations in the Puente Hills, at one horizon 

or another, carry petroleum or its asphaltic residue. In the region 

developed by the Puente Oil Company, near the center of the productive belt, oil is derived from sandy strata low down in the lower 

division of the Puente shale. The Puente sandstone is bituminous at 

several points, particularly along the eastern crest of the hills, 

although as yet it affords no oil. The.upper shale, also unproductive, 

nevertheless carries a small content of disseminated oil. The Fernando formation has proved extremely rich in several localities. 

The presence of oil at the horizons mentioned is not, however, an 

argument for their productiveness at all points. The factors of 

structure and of the original occurrence or formation of petroleum 

are always to be considered.

While it is evident that severe disturbance of the strata has been 

the chief determinant of the presence and development of the succession of oil fields along the southern face of the Puente Hills, such 

occurrences as that of the Chino field, on the eastern crest of the 

hills, 5 miles southwest of the town of Chino, are evidences of the 

possibilities, under right conditions, in the regions of subordinate 

folds. As yet, however, prospecting of the secondaiy and lateral 

anticlines has been but slight.

Oil. FIELDS.

The developed oil fields of the Puente Hills include the Whittier, 

immediately east of Whittier; the La Habra, on La Habra ranch, 

3 miles southeast of the Whittier field; the Puente, on the summit 

of the ridge in its most contracted portion; the Brea Canyon, 1£ 

miles southeast of the Puente field; the Olinda, on Olinda ranch, 

7 miles northeast of Fullerton, and the Chino, about 5 miles southwest of Chino. The last-mentioned field, although within the general anticline of the Puente Hills, is independent of the other 

petroleum-producing areas, which lie at intervals along the belt of 

highly disturbed strata on the south side of the hills. (PI. XII.)

WHITTIER FIELD. 

LOCATION.

The producing territory of the Whittier oil field lies on the southern slope of the Puente Hills, beginning within a mile of the town 

of 'Whittier and extending in a S. 65° E. direction about 2£ miles.

GEOLOGY.

The field is developed along the south side of -the well-defined 

Puente fault zone, in southward-dipping conglomerate, sandstone, 

and argillaceous beds of the Fernando formation, which successively 

abut against different members in the siliceous and other shales of
U.S. GEOLOGICAL SURVEY 

CHARLES O.WALCOTTj DIRECTOR

R. 11 W. R.IOW. R.9 W.

BULLETIN NO.3O9 PL.XII 

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AJfOft/a CO,8ALT/MOR£, MO. R.IOW. R.9W.

TOWNSHIP AND SECTION MAP OF THE PUENTE HLLLS OIL DISTRICT, SOUTHERN CALIFORNIA

Scale 

o i ^ a miles

Well locations largely from oil 

companies' maps

19O6
PUEffTE HILLS: WHI.TTIER FIELD. Ill

the Puente that lie with varied dip on the north of the fault. The 

line of producing wells trends N. 65° W., in marked divergence with 

the strike of the formations, which varies but little on either side of 

an east-west line. The wells, in other words, follow the trend of the 

fault rather than the strike of the beds, and in the Fernando formation the oil horizons vary with the strata that are brought into contact with the shale across the fracture plane. In the eastern portion 

of the field, for example, the petroleum is in beds considerably higher 

than in the western portion. An apparent exception to this tendency of well development to follow the fault plane exists in the 

long parallel strings of Murphy and Central wells that lie on either 

side, of an east-west property line, a little north of the south line of 

sec. 23, T. 2 S., R. 11 W. (See PL XIII, A.) These wells closely 

follow the strike of the formation, with which, however, the property line, the determining factor in their location, happens to be 

nearly coincident.

North of the plane of separation of the Fernando and Puente formations the wells drilled in the Puente beds have been, with a few 

unimportant and slight exceptions, total failures. It would seem, 

therefore, that for this field the productive belt is in the Fernando. 

formation adjacent to the plane of fracture or of unconformity. The 

width of this belt is. uncertain, but is at least between a quarter and 

half a mile, and the oil is found at greater depths in proportion as it 

is distant from the line of fracture. The strata affording oil in the 

Whittier field are members of the Fernando formation and consist 

of coarse gray to yellow-brown conglomerate, heavy-bedded sandstone, and pulverulent argillaceous sand that shades locally into distinctly arenaceous clay. Here and there the clay has been hardened by the presence of lime, and in some of the sandstone also there 

are hard quartzo-calcareous concretions, such as have been observed in this formation at other points in the hills. Locally, also, 

the sandstone shows the presence of more or less dry bitumen, which 

imparts to the rock a brown color. The exact position of these beds 

in the formation as a whole is unknown, by reason of faulting, because 

of the unconformity which exists between the Fernando and the 

underlying formations, and from the fact that as yet the various 

divisions have not been identified and correlated by their fossil contents. Furthermore, there is an apparent variation in composition 

along the strike of the formation. The relative position of the beds in 

the eastern and western portions of the productive tract may, however, be traced with comparative precision by reference to strike lines 

which vary but little from east and west; a heavy conglomerate, for 

instance, which lies a quarter of a mile south of the Murphy and^Central wells in the eastern part of the field is found fully half or threefourths of a mile south of the Home wells in the western part. Other
112 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

conglomerates that in the vicinity of the Home wells outcrop in close 

proximity to the.fault line may be those cut at considerable depth in 

the Murphy and Central group.

The Puente shale north of the fault line is in part siliceous, in part 

earthy, and in places it is brown from the presence of bitumen as well 

as of iron. In many of the layers may be found traces of the low 

organisms, foraminifera, etc., which are usually present in the Miocene 

formations, especially the Monterey. Limestone concretions also 

occur. Whether the shale outcropping adjacent to the fault belongs 

above the Puente sandstone or below was not.positively determined. 

.All three divisions of the formation perhaps occur at one point or 

another in the field, but the contorted and faulted condition of the 

beds requires the utmost detail of study for their successful correlation, and this the present reconnaissance did not permit. It is sufficient for the immediate purposes of this report that the Miocene shale 

(Puente) has been identified in faulted or unconformable contact 

with the oil-bearing members of the Fernando.

The number of oil-bearing horizons in the Fernando formation 

adjacent to the fault line and the fact that they are in contact with 

the bituminous shale of the Puente suggest a passage of the oil from 

the older formation into the various members of the younger, the 

fault having been not only a disturbing element affecting the positions 

of the strata, but also, perhaps, .the means of affording a channel for 

the transfer of the fluid from the entire thickness of Puente shale to 

the several horizons of the Fernando. The fault plane, in fact, here 

seems to have performed in an enhanced degree the same function as 

the plane of unconformity between the two formations, so conspicuous 

an element in many of the oil fields of California. The younger formation of open, porous sandstone and conglomerate lies in contact 

with the bitumen-bearing shales of the Puente; in the one instance by 

faulting, in the other by deposition. In both instances the receptive 

strata of the younger formation, which happen to lie against or upon 

the older beds, have become impregnated with the bitumen capable of 

removal through wells.

That the surficial relation between the Fernando and the Puente 

beds is one of faulting rather than simple unconformity is argued from 

the irregularities of strike and dip of the various strata, but beneath 

the surface the unconformity which exists at the base of the upper 

Miocene at almost every point in the Coast Range is undoubtedly also 

present.

STRUCTURE.

The nature of the Puente fault zone is exhibited in a complex of 

fractures observable a few hundred feet north and northwest of the 

principal group of Central wells. It consists of two principal breaks.
U. S. GEOLOGICAL SURVEY 

WHITTIER OIL FIELD, LOS ANGELES C

A, Wells along property line of Central Oil Company and Murphy Oil Company, loo
PUENTE HILLS: WHIXTIEB FIELD. 113

The southern, in the eastern half of the field, receives at an acute 

angle the axis of an anticlinal fold, which in the region of the Chandler 

wells is conspicuously developed in the Fernando formation to the 

south of all recognized fault planes. The northern break is traceable 

but a short distance to the east; but in alignment with it, a mile distant, is a sharp crumple in Puente strata. West of the Murphy-Central region the fault zone resulting from the union of the fractures thus 

described passes immediately north of the productive wells of the 

Fidelity, Turner, and Home companies and thence toward the west 

end of the hills. The block between the two faults just mentioned 

involves both the Fernando and Puente formations. The foregoing 

details derive their chief interest from their 'possible bearing on the 

occurrence and yield of petroleum in the region discussed.

Toward the west end of the Whittier field, especially in the vicinity 

of the Home Oil Company's wells, the Fernando beds appear to be 

slightly overturned. (See PL XI, sec. A-B.) North of the fault 

line, in a little ravine north of Home well No. 11, the Puente shale 

inclines to the north at an angle of about 25°, while immediately adjacent to the fracture it dips southward at a steep angle. The Fernando 

beds next to the fault are approximately perpendicular, but a little 

farther south, in fact as far as Home well No. 7, they dip to the north 

at angles varying from 75° to 90°. (See PL XIII, £.) A short distance south of well No. 7, however, the dip changes to 75° or 80° S. in 

rather coarse conglomerates, while the inclination of the alternating 

bands of sandstone and conglomerate from this latter point 'Southward to the edge of .the hills gradually becomes less.

The conditions in the vicinity of the East Whittier and Bulla wells, 

near the west edge of sec. 24, T. 2 S., R. 11 W., have already been, 

referred to on page 111, under the heading "Geology." (See PL XI, 

sec. C-D.) A short distance south of the crest of the hills, in the 

region of the Bulla wells, the strata show sharp compression, together 

with a distinct break in stratigraphic continuity, Fernando conglomerate abutting against Puente shale, both dipping north. The 

relationship between the formations- appears to mark the locus of a 

fault in this region. The line of division is, moreover, in the direct 

trend of the suspected fracture,as recognized farther west. North 

of the fracture the Puente shale and sandstone lie in somewhat confused relationship; it is possible that a second fault parallels the 

main fracture, or it may be that the strata are folded into a sharply 

compressed syncline.

OIL WELLS.

The wells of the Whittier field draw their supply wholly from the 

members of the Fernando formation. They range in depth from 

about 800 feet close to the fault line to nearly 2,500 feet at a distance
114 OIL DISTRICTS QF SOUTHERN CALIFORNIA.

from the break, the width of the productive zone as at present developed varying from an eighth to a quarter of a mile. The sandy 

members of the formation, rather than those of clayey consistency, 

yield the petroleum, although in some instances the material is comparatively fine, while in others it is coarse and even conglomeratic. 

The gravity of the oil varies from 16° to 23° B., the higher grade 

being reported from greater depths, although, perhaps, from younger 

beds. It is to be remarked also that some of the shallow wells are 

the older and that their condition is now far from satisfactory, water 

having in many instances found its way into oil-bearing strata, with 

the consequent effects of oxygenation and the transmission of more 

or less impurities. The daily production of the welis is said to vary 

from 2 barrels in the oldest to 300 in the newest and deepest.

Among other groups of wells within what may be regarded as the 

confines of the Whittier field are the Chandler, a group of four wells 

1 mile southeast of the Murpliy and Central wells. These were about 

the first drilled in the Whittier field, but are now abandoned. Their 

location was probably determined by an oil seepage from the sandstone and conglomerate. They were, however, primitive in equipment and shallow and afforded but a light yield of heavy oil. At 

this point the Fernando formation lies in an anticline secondary and 

parallel to the main fold in the hills. The beds south of the axis 

dip from 45° to 70°, and those north of the axis, with steeper dip, 

apparently abut against the Puente fault, being in contact with the 

Puente shale forming the central and higher portion of the hills. 

This shale also pitches to the north immediately adjacent to the 

fracture, a position that may be either normal or overturned, the 

latter occurring at many places within the zone of severe crumpling 

along: the southern face of the Puente Hills. The Chandler wells are o

located a little south of the axis of the secondary anticline referred, 

to above.

One or two wells have also been drilled in the same general region 

as the Chandler group, but in the Puente shale north of the fracture. 

As in the case of other wells in this formation in the territory adjacent to the Whittier field, the results were negative. The fact, however, that the Puente shales or their included sandstone locally carry 

oil is evident from the field developed by the Puente Oil Company, 

but no law governing this relationship has been discovered. In case 

the oil is not originally contained in the formation, its presence is 

probably due to the porportion of sandy members a factor widely 

variable from point to point.

At the summit of the Puente Hills, about 1 £ miles north of Whittier, 

near the east edge of sec. 16, T. 2 S., R. 11 W., the North Whittier 

Oil Company has drilled two wells on the north limb of the main
PUENTE HILLS: LA HABRA CANYON FIELD. 115

Puente anticline, within a mile or two of the west end of the fold. 

The wells are sunk in Fernando conglomerate and sandstone, which 

have a regular dip. They were not a marked success and no more 

have been drilled in the immediate vicinity, although at depths be.- 

tween 900 and 1,500 feet oil-bearing strata affording a small yield 

were encountered. These wells are of especial interest, since they 

are among, the first to be exploited in the younger formation on the 

north limb of the anticline. Faults of importance have not been 

observed in this locality. From surface indications the position 

of the North Whittier wells seems to be somewhat analogous to that 

of other wells in such productive fields as Coalinga, Midway, and 

Sunset, where petroleum occurs in formations having remarkable 

evenness of dip, strike, and succession.

The productive wells of the Whittier field embrace those of the 

Home, Turnbull Canyon, Turner, Fidelity, Strong, Central, Warner, 

and Murphy oil companies. Other companies have drilled at various 

points in the field, but thus far without success. In general, the 

wells immediately south of the fracture have been found productive; 

those to the north unproductive. (PI. XIV, J5.)

LA HABRA CANYON FIELD. 

LOCATION.

The region of La Habra Canyon occupies the heart of the Puente 

Hills, midway between the Whittier and Puente fields. It has an 

east-west length of about 3 miles, the productive territory being near 

the west end.

GEOLOGY.

The geologic relations between this and the fields on either side 

have not been fully established, but in a broad sense the three are 

similar, the principal differences consisting in the details of folding, 

their position within the general anticline, and the strata pierced. 

The formations of the region include the upper and lower members of 

the Puente formation, together with the intervening sandstone, and 

the Fernando conglomerate, sandstone, and clay. Exposures of the 

lower shale are limited to the center of the general anticline in the 

eastern part of the area; the Puente sandstone outcrops in the middle, 

a trace of the upper shale overlying, while the Fernando formation 

almost closes over and around the older beds at the west end. West 

of this the conglomerate again gives way to outcrops of the Puente, 

which in the Whittier field occupies a large proportion of the. ridge 

crest.
116 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

STRUCTURE.

The older formations in the heart of the area lie in anticlinal position, the flanks of the fold showing sharp local crumplings, with possibly a continuation of the faults that occur in the fields to the east 

and west. The prevailing strike is N. 70°-80° W. The position of 

the Puente fracture, if it be present (or of its alternative, the line of 

unconformity) is considerably nearer the axis of the general anticline 

than at points to the east, a few hundred feet only separating the two 

if, indeed, they are not locally coincident. As in other fields, there 

is here also a marked divergence between the trend of folds and the 

course assumed by the line of maximum disturbance. Along this line 

the development of oil territory has taken place. In the vicinity of 

the Union and New England wells, at the west end of the district, 

the strata show marked crumpling, with some evidence of faulting, 

although this is north of what appears to be the main anticline as 

traced from the east. The locality is one of especial confusion, owing 

to the compressed condition of the folds, to the proximity of the horizon of unconformity between the Fernando and older beds, and to the 

crushing that the rocks have undergone.

Of the several flexures present the most important appears to be 

that which passes directly north of the Union wells, in apparent continuation of the princpal anticline of the hills to the east. It lies considerably south of the point of greatest disturbance in the field,which 

is apparently in the immediate region of the New England wells. 

Farther west it possibly merges with the fold which appears south of 

the fault zone at the east end of the Whittier district. North of this 

fold are others, both anticlines and synclines, in one of which are the 

New England wells and an isolated well of the Union Oil Company. 

The rocks along the axis of this fold show severe crushing, with indications of considerable displacement.

At the head of the east fork of La Habra Canyon the structure again 

shows marked complexity. Sharp crumples, even faults, exist. 

The most conspicuous displacement is between the hills on either side 

of the road over the divide. The unconformity also is very marked, 

the line between the Fernando conglomerate and the siliceous shale 

of the Puente sweeping in a broad curve to the southern base of the 

hills and passing thence to the entrance to Walnut Canyon and the 

hills separating this from the entrance to Brea Canyon. Whether 

faults exist along this line is uncertain. North of the more conspicuous fracture the lower body of shale, beyond an interval of sharp 

minor folds, assumes a northerly dip, which is maintained by the 

succeeding formations to the northern limit of the hills. South of 

the fracture the shale, together with a small fragment of Puente sandstone, appears to lie in a sharp syncline, which is succeeded by an anti-
PUENTE HILLS: PUENTE FIELD. 117

dine, but there is much confusion in the details of structure, and 

these have not been determined. The changes in structure so frequently encountered in the Puente Hills are well exemplified in the 

present locality. Within a quarter to half a mile to the east the folds 

are less complicated, but the flexures continue to the Puente oil field, 

with faults, doubtless, in considerable number, but difficult of detection in the homogeneous shale.

The La Habra locality is noteworthy also in that the line of faulting 

and unconformity traceable westward from the Olinda and Brea 

Canyon fields here approaches the system of successive folds that 

characterizes the region of the Puente Oil Company's wells. Farther 

west the relations of these folds are even more intimate, and the zone 

of disturbance carrying them is greatly contracted.

OIL WELLS.

The only wells of the La Habra district are those of the Union and 

New England oil companies. They lie in two groups; the Sansinena 

wells, belonging to the Union Company, are situated, in the gulch 

bottom a little south of the axis of what to the'east is probably the 

main anticline; the other group is on the crest of the ridge, half a mile 

to the northwest, in highly disturbed strata close to the axis of one of 

the subordinate folds. The production of these wells is not large and 

the oil is comparatively heavy. A maximum depth of nearly 2,000 

feet has been attained, although most of the wells are said to be much 

shallower. Oil is reported to the depth of 1,850 feet. The formations ii\ the deeper wells embrace 300 or 400 feet of Fernando conglomerate at the top, followed by shale arid sandstone below, in part, 

perhaps, of the Fernando, in part older.

PUENTE FIELD. 

LOCATION.

The Puente oil field lies along the crest of the Puente Hills and of 

the general anticline forming them. It is about \\ miles northwest of 

the mouth of Brea Canyon and 3 miles east-southeast of the developed 

territory of La Habra Canyon. The productive area is approximately \\ miles long by one-eighth mile wide, the length corresponding with the general strike of the beds (N. 70° W.).

GEOLOGY.

The formation underlying the region of the Puente field is the 

lower Puente shale, which, as shown by the well logs, is here largely 

interstratified with beds of fine sand varying in thickness from a few 

inches up to 100 feet or more; an unbroken thickness of 100 feet is,

Bull. 309 07 9
118 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

however, exceptional. Oil occurs at intervals from a depth of less 

than 300 feet to nearly 2,000 feet. The shale lies at the very heart of 

the Puente anticline and is, therefore, except in one or two places, 

not only the oldest body of rock' e5cposeci northwest of Santa Ana 

River, but the lowest formation in which oil has been found in the 

general region of the Puente Hills.

Flanking the shale on the north is the Puente sandstone, which is 

overlain by a thin body of the upper shale, and this in turn at the 

periphery of the hills by the Fernando conglomerate and associated 

beds. The dip from the crest of the ridge northward is to the north 

with marked regularity. South of the crest, opposite the developed 

territory, the shale extends to the valley level, the younger formations 

lying buried beneath the'more recent wash. The dip on the south 

side of the ridge, especially in the eastern half of the field, is variable, 

indicating a rapid succession of synclines and anticlines, each lower 

as the edge of the prairie is approached. Opposite the western half 

of the field the folds are less pronounced and the prevailing dip on 

the lower slope of the hills is northward, changing to southward 

higher up.

Opposite the Puente oilfield, for a distance of 2 or 3 miles along 

the southern base of the hills, the Fernando formation is wanting in 

outcrop, this being the only break in its continuity from a point near 

the Santa Ana to San Gabriel River. The ridges which usually mark 

the outcrop of the Fernancfo are also wanting, having been carried 

away, doubtless, by erosion at the time when the Pacific washed the 

base of the hills. It may be due to this that the Puente sandstone 

lying buried with the younger formation beneath the terrace gravels 

of the valley is also lacking along this same stretch of country. On 

the other hand, the disappearance of the Fernando and Puente sandstone may be by faulting, which is kndwn to have disturbed the 

structural relations both to the east and to the west. North of the 

hills the strike of the Fernando and underlying formations changes 

from its normal direction of N. 65°-70° W. to nearly northeast. The 

Fernando passes from the flanks of the hills to the valley of San Jose 

Creek, while the Puente sandstone and the underlying shale enter into 

those subordinate folds of northeasterly trend which characterize the 

northern side of the hills from this point eastward.

STRUCTURE.

Without a detailed survey it is impossible to delineate the individual 

flexures of the Puente field. They are many in number, parallel with 

one another, of varying length and amplitude, and some are but 

slightly less important than the main anticline itself. There is no 

doubt, however, that the axis of the principal fold is here nearly coin-
PUENTE HILLS: PUENTE FIELD. 119

cident with the crest of the ridge, and the oil territory has been developed chiefly in proximity to this axis on either side. (See PI. XI, 

sec. E-F.) . From the Puente field eastward oil development has followed the line of the suspected fault and unconformity, although the 

main anticline has been but slightly prospected. Wells north of the 

line referred to, however, have been generally unsuccessful. The 

axis of the anticline has a gentle westerly pitch, which is maintained, 

except for modification by faulting, to a point beyond the New England Oil Company's wells.

Whether faulting has taken place in the immediate region of the 

wells is undetermined. It is suggested, however, both by the sharp 

crumpling which the beds have undergone and by the fact that the 

line of development is directly in the trend of the fault which has 

been recognized at the head of the east fork of La Habra Canyon.

The locus of the main Puente fracture (or of its alternative, the unconformity) lies at the southern base of the hills and is traceable eastward 

to the Brea Canyon district and westward to the head of La Habra 

Canyon. The lack of confirmatory evidence to the contrary and the 

irregularity in the trend of the interformational line argue rather for 

unconformity than for faulting, although the possibility of the latter 

must be admitted. A feature of the field is the convergence of the 

axes of several folds that farther east are of considerable prominence.

OIL WELLS.

The wells of the Puente oil field are those of the Puente Oil Company, which now penetrate the lower shale of the Puente formation 

to a depth of nearly 2,000 feet, although for years 800 or 900 feet was 

the maximum. Oil is drawn from many layers of sand of varying 

thickness, some of the lower being especially productive, and others 

affording but a minimum, yield. The depth of 2,000 feet attained by 

the drill, together with, the amount of erosion that must have taken 

place from the arch of the fold, indicates that this division of 'the 

Puente is at least 2; 500 feet thick, the thickness of the entire formation 

being still undetermined.

The wells of the Puente Oil Company are among the oldest in California, dating back to the year 1885. Their production until recently 

has never been large, but has been maintained with marked constancy. Some of the newer wells have yielded 100 to 200 barrels of 

oil a day; but, as in the case of all other fields, .this amount has 

decreased as the pressure has diminished, and the territory has become 

drained. During 1905 but a few of the wells in this field were being 

pumped, and these only to avoid flooding. The oil is of an olive-green 

to black color by reflected light and varies in gravity'ffom 22° to 35° B.
120 OIL D1STKICTS OF SOUTHERN CALIFOENIA.

BREA CANYON FIELD. 

LOCATION.

Brea Canyon finds exit from, the Puente hills 5 miles north-northeast 

of Fullerton in the vicinity of one of the most important oil districts 

in the territory. Below the forks the canyon assumes the trend of 

the main Puente anticline and lies close to the zone of maximum disturbance. At a point where the beds have been locally crushed it 

cuts directly through the outer terrane of the hills and passes into the 

valley. (See PL XIV, A.)

GEOLOGY.

The Brea Canyon oil field is developed in the zone of highly disturbed strata along the lower canyon in a general N. 65°-70° W. direction. The formations include the Fernando conglomerate, sandstone, 

and arenaceous clay, the upper shale of the Puente, the Puente sandstone, here limited in area, and the lower division of the Puente, with 

its shale, interbedded sandstone, and lenticular masses of limestone.

The Fernando formation is well exposed along the lower portion 

of Brea Canyon. The higher and outer members consist of bright 

gray and yellow conglomerate, sandstone, and arenaceous clay.' 

Within and lower in the series conglomerate becomes somewhat 

less conspicuous and traces of bitumen begin to appear. This feature is especially noticeable at the entrance to the canyon proper. 

Here also the sandstone, with a few pebbles, shows the concretionary structure observable elsewhere in the hills, but the formation is 

not on this account to be confounded with the Puente sandstone, 

for otherwise there are marked lithologic differences, and in addition 

to these the fossils of the younger beds are especially abundant and

characteristic. The conglomerate of the Fernando formation enters 

largely into the composition of Brea Ridge, extending eastward far 

beyond the region of the Santa Fe wells. Westward it may be 

traced to its disappearance beneath the valley opposite the Puente 

oil field. Still lower in the series and occupying the inner or northern slope of Brea Ridge are several bands of petroliferous sandstone that display a few concretions and here and there a pebble 

mass and are interbedded with arenaceous clay. Two of the sandstone bands are particularly conspicuous, one well down on the 

north face of the ridge, the other north of the ridge near the creek 

channel. It is possible that these may lie at the same horizon, but 

that they are duplicated by faulting, the valley of the creek being 

coincident with a line of marked local disturbance. These beds 

carry fossils of lower Pliocene age. (See list, p. 107.) In the hill 

north of Brea Canyon there is a further succession of beds of clay, 

sandstone, and conglomerate, one or two of-the conglomerate beds
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XIV

.1. LA BREA CANYON FIELD, ORANGE COUNTY. 

Looking southeast,

Jl. CHARACTERISTIC PUMPING PLANT, WHITTIER FIELD, LOS ANGELES COUNTY.
PUENTE HTLLS: BEE A CANYON FIELD. 121

being particularly persistent. Midway between the base and summit of the hill there is a calcareous pebbly layer, which is also fossiliferous, yielding a lower Pliocene fauna. The beds forming the 

lower slope north of the stream, although perhaps not a repetition 

of the beds south of the canyon, are unquestionably of the same 

formation.

A small body of limestone a few feet across, together with a little 

shale similar to the Puente material, was observed in the Fernando 

of Brea Ridge. A similar occurrence was noted near the Union 

wells in the La Habra district. Both are unusual and inexplicable.

Opposite the entrance to Brea Canyon the Fernando formation is 

succeeded on the north by shale, thin-bedded sandstone, and calcareous concretions characteristic of the lower divison of the Puente 

in this region. A narrow dike of diabase extending in an east-west 

direction for nearly a mile intrudes these Puente beds a short distance north of Brea Canyon. The shale and sandstone are directly 

traceable into those which occupy the heart of the general anticline 

2 miles to the west, in the region of the Puente Oil Company's wells. 

They are overlain by the Puente sandstone in the eastern half of 

this field, and at the divide between Brea Canyon and the drainage of the Olinda field the upper shale in turn appears, in contact 

with the Fernando. In the'western half of the field the sandstone 

and the overlying shale are wanting, having been carried beneath 

the surface, possibly by the Puente fault, which may here pass along 

the northern slope of the canyon. Notwithstanding, however, the 

evidences of faulting in the severe crushing which the strata have 

undergone, it is also possible that the unconformity admittedly 

existing between the Fernando and the older formations may prove 

to be accountable for the variation in the succession of strata, the 

younger members of the earlier formation having been uplifted and 

removed prior to the deposition of the later conglomerate and associated sediments. East of the east fork of Brea Canyon the Puente 

sandstone regains its prominence, and fronj this locality almost to 

the valley of the Santa Ana and the lowlands about Chino it is the 

most conspicuous formation of the hills.

STRUCTURE.

The structure about lower Brea Canyon is difficult to read, but 

from what has already been said the inference may be drawn that 

it is probably in direct general continuation with that both to the 

east and west; that is, the sharp folds, faults, and unconformity 

existing in the hills of the Santa Fe region extend along the northern slopes of the canyon, passing thence across the spur immediately 

west of its mouth to the edge of the prairie opposite the Puente oil
122 OIL DISTRICTS OF 'SOUTHERN CALIFORNIA.

field. The formations north of the fault line, or of the line of 

unconformity, show the usual variety of flexures, the shale being 

especially crumpled, the Puente sandstone less so. Syncline and 

anticline appear with a few secondary faults, parallel to the main 

fracture. An instance of the minor faults is to be found in the 

face of the ridge between the east and west forks of Brea Canyon, 

where Puente sandstone lies vertically against slightly undulating 

beds of the lower division of the Puente shale, indicating the dragging-down of the-younger-horizon, in connection with the sharp fold" 

from which the chief displacement' hajs been 'developed. Toward the 

crest of the hills is the main axis of the general anticline, the fold 

being here somewhat modified by the radiate flexure passing to the 

northeast between the forks of Brea Canyon.

The position assumed by the Fernando beds south of the Puente 

fault is of the greatest interest from a structural standpoint. The dip 

of the conglomerate and sandstone north of the canyon, opposite the 

wells of the Brea Canyon and Menges oil companies, is 50°-90° N. 

(See PI. XI, sec. G-H.) There appears to be a considerable difference in the succession as well as in the composition of the beds on the 

two sides of the gorge, yet in the uncertainties of lithology their correlation can not be denied as possible. A doubt exists as to whether 

the strata immediately south of the supposed fault lie in an anticline, 

as in similar positions at several points along the hills, or whether the 

conglomerate, sandstone, and arenaceous clay have been overturned 

by dragging against the fracture plane in their downward displace-, 

merit. At one or two points there is some evidence of the latter condition; at others there is equal evidence of an anticline; elsewhere all 

is confused. If the anticline exists, its axis lies near the stream channel in the lower portion of the canyon, gradually passing into the 

slopes of Brea Ridge toward the east, to become continuous or but 

slightly en echelon with that of the anticline south of the fault in the 

Olinda field. The line of seepages in the bottom of Brea Canyon may 

mark such an axis and may possibly indicate a fracture developed 

along the crest of the fold. The most satisfactory evidence of an 

anticline aside from the unconnected northerly and southerly dips 

along the canyon exists about the head of the small lateral gulch in 

which the Menges wells are ^situated, the Fernando formation here 

showing the arch of a gentle fold, which, though lying close to the 

Puente fault, may prove continuous with the anticline suspected as 

coincident with the lower portion of Brea Canyon its westernmost 

extension in fact. Moreover, it may be due to the near approach of 

anticlinal axis and fault perhaps to the merging of one into the 

other that the exterior ridges of the hills disappear to the west, the 

fracture alone passing thence along the base of the ridge opposite the 

wells of the Puente Oil Company. On the other hand, near the sug-
PUENTE HILLS: BREA CANYON FIELD. 123

gested fault line north of the Menge's and Brea Canyon oil territory 

there is marked confusion of the strata, and the region is not without 

evidence of a simple overturn adjacent to the line of displacement. 

If this be the case, the line of seepages along the bottom of Brea 

Canyon marks the line of greatest crushing in the Fernando, except 

directly against the fault plane. Whether anticline or overturn, however, the general conditions bearing on the occurrence of the oil must 

be practically the same. The composition of the Fernando is repeated 

in a constant succession of conglomerates, sandstones, and clays.to the' 

bottom of the series,'and crushing, eo;iial uiipler a fold -of either description, must have produced equivalent effects of texture and structure. 

The prime factors in the field are the Puente fault, the crushing 

attendant on its development, and the contact of Fernando and 

Puente beds.

OIL WELLS.

The companies operating.in the Brea Canyon field are the Brea 

Canyon, the Union, and the Menges.. Other companies have drilled 

wells, but thus far without success The wells of the Brea Canyon Oil 

Company occupy a small area on the northern slope of Brea Ridge 

adjacent to the mouth of the canyon, their number being 21. To the 

east, also on the northern slope of the ridge, is the area drilled by the 

Union Oil Company, 32 wells being distributed along the strike of the 

beds for a distance of 1J miles. The Menges Oil Company's property 

adjoins that of the Brea Canyon Company on the west, lying just 

west of the mouth of Brea Canyon. This company has two wells.

The wells of the Brea Canyon Oil Company are sunk in the conglomerate and sandstone of the Fernando formation, which strike 

N. 70° W. and dip about 50° S., both with considerable regularity. 

The strata cut are exposed, in part at least, in the northern slope of 

Brea Ridge and along the stream bottom, and include the bitumenbearing sandstone referred to on a preceding page. It is-impossible, 

however, to affirm that these horizons have furnished even a portion 

of the oil yielded, so at variance are the records of the wells when compared one with another and with surface exposures. It may be that 

owing to the crushing that has taken place adjacent to the fault and 

its possible extension to the region of'the wells oil has filtered from the 

beds originally containing it into others until there has been a general 

diffusion of the fluid through the more porous strata along channels 

that for some reason have more readily permitted migration. In 

marked contrast, however, to the fine wells of this company on the 

south side of the canyon are those on the north side, where in strata 

far more disturbed little or no success has been attained. .

The wells of the Brea Canyon Oil Company vary in depth from 600 

to nearly 2,000 feet, in production from 12 to perhaps 1,000 barrels 

per day, in the gravity of their oil from 18° to 26° B. The heavier
124 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

oil is said to come from the upper sands, the lighter from the lower. 

The product of the wells is run to a common tank with a resultant 

gravity of between 21° and 22° B.

The westerly wells of the Union Oil Company adjoin on the east 

those of the Brea Canyon Company, and the territory in which they 

are drilled, except for a slight undulation of the strike from a few 

degrees north of west to an equal amount north of east, is stratigraphically .and structurally similar so far as surface exposures indicate. A marked difference in the productiveness of the two areas 

has been revealed by development, however, the many conditions in 

depth familiar to all students of oil occurrence probably being sufficiently variant in the two areas to cause the widely differing results 

obtained. It is unsafe as a general rule to predicate the success of a 

proposed group of wells upon that of a group already drilled, and, on 

the other hand, it is equally difficult to offer a tenable reason for the 

superior yield of one area over another, the conditions available for 

observation in the two being practically the same. Where there is a 

noticeable variation in surface conditions between two localities 

there is likely to be an equal variation in underground conditions, 

and it would not be unreasonable to expect a marked difference 

in the results of drilling. In illustration of this may be compared 

the eastern part of the Union Oil Company's tract in Brea Canyon 

and the western part already referred to. In the eastern part the 

strata show a distinct bowing to the south, and, moreover, the area 

is in proximity to a complex of folds that are traceable from the 

Olinda field. The conditions in the western part are more regular, 

the beds dipping rather uniformly toward the south. While in the 

light of experience it would be impossible to predict whether the 

eastern area would be more or less productive than that a mile to the 

west, it would be a fair inference that there would be a material difference in the yield of the two, and such a difference has been found by 

exploitation.

The territory of the Menges Oil Company, which adjoins that of the 

Brea Canyon Company on the west, is structurally at variance with 

both productive tracts described above and has so far yielded smaller 

wells. The general horizon at which oil is obtained by the Menges and 

the Brea Canyon companies is the same, but between the two tracts, 

strongly developed at the sharp bend in the canyon, is a compound 

flexure involving the oil-bearing strata, in part at least, of both properties. The flexure is as local as it is sharp, and 'disappears within a 

short distance of the stream. In the Menges tract, however, the strata 

are more disturbed than in that of the Brea Canyon Company, showing local and abrupt variations in both strike and dip, at one or two 

points with distinct overturns having a northerly dip.

The foregoing discussion has been carried to considerable length at 

this point because of the typical example afforded by the Brea Can-
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XV

PANORAMA OF OLINDA OIL FIELD. 

From Olinda Ridge, Orange County, looking west to east.
PTJBNTB HILLS: OLINDA FIELD. 125

yon field of the varying conditions attendant on the occurrence of 

petroleum within a comparatively small area. This field illustrates, 

also, the impossibility of offering a definite opinion regarding the 

probable productiveness of a particular territory, an opinion frequently asked of the geologist by all interested in the petroleum 

industry.

OLINDA FIELD. 

LOCATION.

The Olinda oil field lies 6 miles northeast of Fullerton, just within 

the southern edge of the Puente Hills, near the entrance to Soquel 

Canyon. It is connected with the main line of the Atchison, Topeka 

and Santa Fe Railway by a branch from Richfields, 4' miles south. 

As developed, the field extends along the strike of the measures, N. 

65°-70° W., about a mile and a half, the breath of the oil-bearing zone 

varying from one-eighth to one-third of a mile. The field is supplied 

with water from wells a mile or two out in the valley. In the immediate vicinity of the productive area the principal features of topography 

include the main mass of hills, an exterior ridge which borders Telegraph Canyon on the south and extends for a mile beyond the entrance 

to Soquel Canyon, and an inner valley separating the hills from the 

exterior ridge. Development -has taken place in this valley and on 

the lower slope of the main mass of the hills to the north. (See 

PI. XV.)

GEOLOGY.

The formations involved in the Olinda field embrace the upper and 

lower Puente shales, the Puente sandstone, and the Fernando conglomerate, sandstone, and arenaceous clay. The lower Puente shale, 

the homologue of that in the' Puente oil'field, is exposed principally 

to the east of the developed territory, along Soquel and Carbonne 

canyons, entering but slightly into the higher portions of the ridges. 

The Puente sandstone is confined entirely to the main body of the 

hills, extending north and east from the edge of the field for many 

miles and forming the cap rock on all the higher portions as far as the 

Chino divide. The upper shale is not well developed, and it is questionable whether it is present at some places in more than a trace. 

The Fernando formation constitutes the mass of the ridge south of 

Telegraph Canyon, the point of the ridge between Telegraph and 

Soquel Canyons, the hills west of the entrance to Soquel Canyon, and 

the low bench lands between the latter and Brea Ridge, at the west 

end of the field. It finally enters B*rea Ridge and passes westward 

to the Brea Canyon field. It also underlies a considerable portion of 

the interior valley. These formations all extend to the region of 

Santa Ana River.
126 OIL DISTRICTS Otf SOUTHERN CALIFORNIA.

STRUCTURE.

The Olinda oil fields lie on the southern limb of the general anticline of the. Puente Hills. The prevailing dip of the strata is, therefore, to the southwest, but an opposite dip is encountered at many 

places by reason of subordinate folds developed on the flanks of the 

principal flexure. The axis of the main fold, which trends N. 65°- 

70° W., lies somewhat less than a mile north of the oil belt, those of the 

lesser folds traversing the intervening space.

The northern edge of the oil belt, which is closely coincident with 

the base of the main body of the hills, is the locus of an extremely 

sharp fold that has many of the attendant features of a fault. In 

immediate proximity to it, also, is a trace of the contact between the 

Fernando and older formations, but whether this is a plane of faulting or of unconformity it is difficult to say. Perhaps the conditions 

are the combined results of the two, for the evidence for each at one 

point or another seems almost conclusive. The formations which are 

in contact are the Puente sandstone and the shales beneath and 

above on the north, and the conglomerate, sandstone, and clay of the 

Fernando formation on the south.

The zone of disturbed strata is traceable westward directly into 

Brea Canyon and eastward across the point of the ridge between 

Soquel and Telegraph canyons well into the hills south of the latter. 

It is marked in numerous places by heavy seepages of oil, which, however, appear to be from the Fernando rather than from the older 

beds. Beyond Telegraph Canyon the examination was not conducted in detail, but it is a significant fact that in the vicinity of 

Santa Ana Canyon, directly in the line of maximum crushing in the 

Olinda field, is another area of disturbance found by Mr. Homer 

Hamlin in a hurried inspection of the geologic conditions there 

existing.

The evidence for a fault in the Olinda field consists in an irregular 

succession of beds, a zone of crushed strata for 200 or 300 feet on 

either side of the interf ormational line, sharp flexures with local downward curve of the Puente beds on the north of the suggested plane 

of displacement and upward bend of the Fernando on the south, 

and the high inclination of both formations. These features also 

attest to the development of the fracture subsequent to the deposition of the Fernando, although prior to this period faulting might 

have taken place along a line practically coincident with the later 

displacement. In fact, there is ample proof in the hills area that 

the rocks of the Puente had been considerably folded before the Fernando formation was laid down upon them, and it may be that they 

were faulted as well.
PUENTE HILLS: OLINDA MELD. 127

The suggestion of unconformity is borne out by divergence in dip 

and strike and by the presence in .the Fernando of materials unmistakably derived from the older beds. It is, moreover, in harmony 

with observations throughout a large portion of the Coast Range. 

The fact that in the Olinda field, therefore, the Fernando formation 

lies at one point against the lower shale of the Pueiite formation, at 

another against the upper shale, and at still another in contact with 

the Puente sandstone, may be attributed to unconformity, to faulting, 

or to both. As already mentioned, the writer inclines to the belief 

that both of these causes have contributed their part in the develop- 

 ment of the existing conditions.

The principal features of structure in the Olinda field will now be 

taken up in somewhat greater detail. In the eastern third of the field, 

from the vicinity of the gulch containing Santa Fe wells Nos. 21, 32, 

36, and 38, eastward to the Columbia ground and Soquel and Telegraph canyons, there appear to be two divergent lines of structure, the 

southern line marking the trace of the main fault, or of its alternative 

plane of unconformity between the Fernando and the older beds, 

maintaining the general trend of N. 65° 70° W., and passing across the 

lower portion of Telegraph Canyon; the northern, a line of severe 

crushing, extending more directly eastward or even a little north of 

east and following the gorge of Soquel Canyon. The northern line is 

confined wholly to the Puente formation. The combined effect of 

faulting and folding, together with the divergence in strike noted, has 

brought to the surface, north of the divisional line between Puente and 

Fernando, beds gradually lower in horizon toward the east, the prevailing dip being 25°-60° N. As the divergence increases additional 

crumples, some of them extremely sharp, appear in the Puente beds.

Immediately north of the northern of the two. divergent lines 

referred to above and close to the northern line of wells is located the 

axis of the general syncline that is so persistent and conspicuous a feature along the northern border of the Olinda field. Its trend is N. 65° 

W. and it is especially prominent in the Puente sandstone. This syncline is of especial interest near the center of sec. 9, where are clustered 

several wells of the Santa Fe, Fullerton Consolidated, and Columbia 

(Puente lease No. 1) oil companies. At this point there is considerable uncertainty regarding the stratigraphic horizon, both from the 

crumpled condition of the beds and from the lack of distinguishing 

characteristics. The Puente sandstone appears a short distance 

north of the wells, dipping to the south, but about the wells the strata 

dip northward and have more the nature of arenaceous, granular, and 

muddy shale, with traces of the siliceous variety, in one instance 

faintly organic. On the whole the formation bears considerable 

resemblance to that underlying the Puente sandstone along the lower 

slopes of Soquel Canyon east of the Columbia wells (lease No. 1), and
128 OIL DISTKI.CTS OF SOUTHERN" CALIFORNIA.

yet it is not unlike certain members of the Fernando. The writer is 

inclined to place the beds in the Puente and to regard the area as lying 

within a zone of especial disturbance that is manifest along both the 

main fracture and its northern branch, in all probability in an interfault block. The syncline is traceable in strike from north of east 

through north to north of west, and in a dip correspondingly variable 

from north to west and then to south around the east end of the 

trough, this being especially manifest in the heavier sandstones at 

the point occupied by the Fullerton wells, which lie close to the synclinal axis or a short distance off on its southern limb. Evidences of 

the syncline continue eastward to the bottoms of Soquel Creek in a 

constant repetition of the structural features of the Columbia ground 

(lease No. 1), a westerly dip along the axial line locally as high as 45° 

being especially noticeable. Beyond Soquel Canyon the identity of 

the syncline is lost.

Most of the Columbia wells (lease No. 1) are located on the south 

side of the synclinal trough; some, however, are close to the axis, 

while two or three of excellent yield appear to be in strata that dip to 

the south or are intensely crushed. One of the deeper wells in which, 

up to the time of the investigation, no oil had been found penetrates 

at the collar the organic shale of the Puente. The others, which start 

in heavy sandstone, probably of the Puente formation, are highly 

productive.

The easterly wells of the Santa Fe and those of the Fullerton and 

Columbia oil companies appear thus to have been drilled in the Puente 

formation, in ground whose structure is somewhat uncertain. Most 

of them lie a little south of the line of maximum crumpling. It may 

be inferred, therefore, that the horizon of their oils is approximately 

that of the oils of the Puente Oil Company's wells 5 miles farther west.

Moreover, the logs of the wells indicate the presence in depth of shale

similar to that of the Puente oil field, whereas in other portions of .the 

Sante Fe area the strata are of the more open and porous nature 

characteristic of the Fernando. This similarity of strata penetrated 

in the Puente field and the east end of the Olinda field accounts for the 

similarity of the oils of the two localities. The gravity varies between 

23° and 35° B., the oil of the Olinda field being somewhat the lighter.

Typical Puente shale with steep dip is ex«posed a few feet east of the 

Columbia camp (lease No. 1), several hundred feet south of the eastern 

wells of this company. The outcrop is in line with others of the same 

nature up Spquel Canyon, and it is probably continuous with them, 

the Fernando having here crossed to Telegraph Canyon. Loose 

shale fragments are also found over a considerable area in the same 

general region south of the wells.

Along the middle portion of the field, in the eastern half of the 

Graham-Loftus tract, the strata occupying the face of the hills north
PTJENTE HILLS: OLINDA FIELD. 129

of the wells but south of the syncline, extending from the region 

described in the foregoing paragraph, include yellow and gray concretionary sandstone of the Puente type, with the associated siliceous 

shale and a succession of sandstone and arenaceous shale, also yellow 

and gray but apparently devoid of concretions and of the minor 

organic forms that characterize the Puente. There appear to be two 

formations in juxtaposition one undoubtedly Puente, the other 

closely resembling the Fernando. Their relations suggest the locus 

of the Puente fault, a view strengthened by the sharp disturbance 

affecting the strata in the adjacent gulches. The strike of both 

formations is the same, about N. 70° W. The fault plane, on the 

whole, is believed to pass a short distance south of the northernmost 

of the Graham-Loftus wells, No. 17, but north of the others in this 

vicinity. With the exception mentioned, therefore, all the wells in 

this part of the field have apparently been drilled in the Fernando

formation, and this view is borne out by the fact that conglomerate is 

encountered at various depths in the wells of both the Santa Fe and 

the Graham-Loftus companies. The position of these wells is believed 

to be on the northern limb of the subordinate anticline south of the 

fault.

Outcrops of conglomerate and siliceous shale about 125 feet northwest of the Santa Fe No. 12 well may be regarded as locating the position of the main Puente fracture for this part of the field. The strike 

of the conglomerate ranges from N. 85° W. to east and west; the dip 

35°-40° N. The shale, as usual, shows large crumples for a considerable distance from the fault. The westernmost well of the Santa Fe 

Company, No. 37, is close to the line of rupture, possibly a little to the 

north of it.

The structure just described continues with some variation, not 

only to the west end of the field, but into Brea Canyon and the territory north and south. The locus of the fault as it crosses the divide 

between the Olinda and Brea valleys is obscure, but it is not far from 

the point of least elevation. North of this point heavy beds of Puente 

sandstone lie in vertical or overturned position, bending, however, to 

a southerly dip of 20°"or less as they pass to the summits of the hills 

above. South of the divide and for a mile or more along the southern 

slope of the ridge north of Brea Canyon the siliceous shale of the 

Puente outcrops. Although this shale is in natural sequence with the 

Puente sandstone on the north, it is believed that, on account of irregularities in adjacent areas, the two beds are separated by the Puente 

fault, or at least by a subordinate fracture. In Brea Canyon the syncline that in the Olinda field lies immediately north of the fault disappears, although other flexures in considerable number, among them 

a syncline of some importance, may be observed along the slope of the 

hills to the west.
130 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

In the region of the Santa Fe wells the details of structure for the 

area along the interior valley underlain by the Fernando conglomerate, in which much of the development has taken place, are somewhat 

obscure. In a general way, however, it is evident that east of the 

western group of Columbia wells (lease No. 2) the strata are deflected 

from their general strike of N. 65°-70° W. to N. 45° W. in the vicinity of 

the southwestern Santa Fe wells, thence bending to S. 70° E. and 

passing onward into the ridge south of Telegraph Canyon. A trace 

of a similar and concentric deflection, with marked local folds, exists 

also in the rocks of the older formation northeast of the Fernando area, 

in the hill slopes north of the Santa Fe village, and the flat to the east. 

The explanation may be that compression took place after faulting, 

affecting the strata in a like manner on both sides of the general fracture. Still, this occurrence may be a coincidence rather than one of 

direct relationship in the movements of the beds.

Again, the Fernando formation, though of comparatively steep 

southerly dip in the exterior ridges of the field, assumes a much lower 

angle of inclination farther north in the interior valley region, with an 

actual northerly dip, as evidenced by the logs of the wells of the Graham-Loftus and Columbia oil companies, near the line of the fault or 

of maximum folds. (See PI. XI, sec. I-J, and PI. XVI.) In other 

words, there is apparently, through at least the western half of Olinda 

Valley, an anticline whose axis coincides with that of the valley, trending about N. 65° W.

The anticline is clearly traceable in the eastern face of Brea Ridge, 

the "axis passing through the southern group of wells of the Columbia 

Oil Company (lease No. 2), or probably a short distance to the south 

of all these wells. Evidences of the fold also appear in the structural 

lines that cross the crest of the ridge diagonally in Union ground, a 

mile west of the Columbia wells (lease No. 2), and in some of the 

gulches that cut the northern face of the ridge in the same vicinity. 

The strikes and dips vary according to the position of the beds in the 

fold. It is possible that the anticline continues westward to the Brea 

Canyon field, being identical with the fold suggested along the line of 

seepages in the bottom of the valley. Some irregularity is displayed 

in the disposition of the strata along the eastern third of Brea Ridge, 

the Fernando formation being confined to the southern limb of the 

anticline, though crossing to the north of the axis in the region of the 

Columbia wells (lease No. 2), and possibly farther west, in the ridge 

between the forks of Brea Canyon.

How far to the east the anticline extends is undetermined. It does 

not appear in the Fernando at the point of the ridge between Soquel 

and Telegraph canyons, although the Puente beds here have the opposite or northerly dip and half a mile up Telegraph Canyon show distinct evidences of a fold. It may be that the anticline continues
U, 8. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XVI

Scale 

o too 200 300 400 feet

DETAILED GEOLOGIC SECTION THROUGH OLINDA OIL FIELD.
PUEFTE HILLS: OLINDA FIELD. 131

through to this point, the Fernando, however, no longer bending over 

the crown of the arch.

The direction which the eastward extension of the Olinda field may 

take is somewhat problematic. The development in Columbia ground 

(lease No. 1) follows the northern fracture, or at least the line of excessive disturbance passing up Soquel Canyon to the entrance of Carbonne Canyon; the surface conditions prevailing in the western half 

of the productive territory, however, continue across to Telegraph 

Canyon, except that the Fernando conglomerate is in contact with 

lower members of the Puente than to the west. Apparently the beds 

are somewhat transitional in their nature, gray micaceous sandstone 

and shale lying beneath the Puente sandstone, the precise horizon 

varying from point to point. The structure of the lower beds is very 

complicated. In the northern face of the ridge between Telegraph 

and Soquel canyons the rather heavy gray and yellow gritty sandstone dips to the north, while the associated brown argillaceous shale, 

only 150 feet distant, has a southward inclination. The strike of both 

is N. 65° E. In the southern face of the ridge the principal dip of the 

older rocks is 45°-80° N., although half a mile up Telegraph Canyon 

the beds of the same character begin to show a southerly dip, which 

is maintained well into the hills to the South. The conglomerate south 

of these beds strikes N. 65° W., nearly parallel with the axis of the 

anticline referred to above; it dips 80°-45° S., according to the distance from the fault line. It rests ujjdri older beds that dip in some 

places to the north, in others to the south, the northward-dipping 

rocks lying near the mouth of Telegraph Canyon. The similarity of 

the conditions in Telegraph Canyon and in the western half of the 

Olinda field is thus obvious, and while there are slight differences it 

would, nevertheless, seem reasonable, from surface conditions, to 

expect equal chances for obtaining petroleum along the line of the 

fault or unconformity in the two localities. However, wells at some 

distance from this line, in the Fernando beds on the ridge south of the 

interior valley, have not yet proved successful.

In the discussion of the relations of Fernando to Puente in the region 

of Telegraph Canyon the question of faulting or unconformity arises 

with the same force as elsewhere. The conditions are explicable on 

the basis of an unconformity, the upheaval and erosion of the older 

rocks prior to the deposition of the Fernando being presupposed; they 

may also be explained by faulting, or they may be due to the two 

causes combined.

OIL WELLS.

The oil wells of the Olinda field number over 100, and except a few, 

chiefly along the outer ridge, all have been of wonderful productiveness, yields of 700 to 1,000 barrels of oil per day having been reached. 

The maximum depth attained is 3,000 feet. The wells are ranged
132 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

along two lines, the northern group following the zone of greatest disturbance, together with the fault, and the southern following the land 

line which separates the properties of the Santa Fe and Fullerton Consolidated oil companies and having no connection whatever with the 

structure.

The oils of the Olinda field vary in gravity from 12° to 35° B., the 

heaviest being found at the west end of the field in members of the 

Fernando, those of 18° to 20° B. in the southwestern part, also in the 

Fernando, and those between 23° and 35° B. in the eastern half of 

the productive area in various horizons of the Puente.

CHINO FIELD.

The Chino oil field occupies a small area on the crest of the divide 

between Soquel Canyon and the Chino Valley, 5 miles southwest of 

the town of Chino. It is located on what appears to be one of the 

northeast-southwest flexures that radiate from the main Puente anticline. The wells, four in number, are drilled in the axis of the flexure 

and on either side. They pierce the Puente sandstone and underlying shale, but the details of their logs were unavailable at the time 

of the writer's visit. Aside from their commercial value, they are of 

especial interest as suggesting the possibilities of at least some of the 

subordinate folds in the hills.

CONCLUSIONS CONCERNING FUTURE DEVELOPMENT.

Whether petroleum will be obtained north of the line of maximum 

disturbance in the Puente fault zone, in rocks adjacent thereto, is 

questionable. Thus far wells in this position have been unsuccessful. 

A reservoir of coarse sand or other open-textured rock is .filled with 

oil at the expense of the finer strata in which it may prove to have 

been but temporarily stored, or in some of which it may have even 

originated. Under conditions such as have been described, it may be 

inferred that in the region of the fault, along the southern face of the 

Puente Hills, the oil has been drawn from the beds north of the fracture zone into the more crushed and hence more open and porous 

strata of the same age south of it, and also into the still more receptive 

reservoir of coarse sediments presented in the Fernando formation. 

How great an area north of the fault may have thus been drained it 

is impossible to say.

An argument in favor of productiveness of the Puente formation 

away from the zone of faults is presented by the Puente Oil Company's wells, whicli are drilled in an anticline in the lower division of 

this formation. Similar evidence is also offered by the wells of the 

Chino Oil Company, which penetrate the Puente, including the sandstone, on a fold subordinate to the main Puente anticline, yet not far 

from its axis. That the lower Puente shale in these hills is generally
PUENTE HILLS: YIELD AND GRAVITY OP OIL. 133

oil bearing in some degree is recognized, that the Puente sandstone is 

also impregnated with bitumen is evident, but that the shale and the 

associated sandstone are everywhere impregnated to such an extent 

as to render them of economic value, under structural conditions that 

would be regarded as favorable, is improbable.

PETROLEUM OF THE PUENTE HILLS DISTRICT.**

YIELD AND GRAVITY OF OIL IN DIFFERENT FIELDS.

The yield of the individual productive wells in the Puente Hills 

varies from 1 to over 1.000 barrels per day, those in the Puente 

field giving the lowest averages and those in the Brea Canyon field 

the highest. The wells of the Whittier field produce oil varying 

from 14° to 24° B., the yield of the individual wells running from 

2 or 3 barrels to nearly 175 barrels per day (in one well), although 

it is said that one or two wells went as high as 400 barrels0 at the 

start. The gravity of the Puente field oil runs from 28° to 34° B., 

but the average yield of the wells is lower than in any other part of 

the district, and none of the wells have gone much over 100 barrels 

per day, even in their prime. In contrast with the low production 

and high-grade oil of the Puente field is the high production and 

medium-gravity oil of the adjacent Brea Canyon field. The gravity 

here ranges from 18° to 26° B., while some of the wells yield as high 

as 1,000 barrels per day. Several flowing wells have been struck in 

this territory, one at least, it is said, gushing with a pressure of 

more than 250 pounds to the square inch. The Olinda field furnishes both high and low grade oil, the high grade, with a maximum of 35° B., coming from wells in the northeastern part of the 

field yielding from 2 or 3 to 150 barrels per day, and the low grade, 

with a range of 18° to 20° B., coming from wells in the west end. 

Six "gushers" haA7e been developed at Olinda, one of which is said 

to have flowed at the rate of 20,000 barrels per day for a short time. 

One of the flowing wells on the Santa Fe property is now (October, 

1905) flowing under a pressure of 100 pounds to the square inch.

FACTORS IN YIELD OF WELLS.

The factors governing the yield of oil wells, aside from the natural 

conditions porosity of rock, pressure, etc. are usually those connected with the manipulation of the wells, such as size of casing, 

loss of tools, caving in of casing, or accidents of one kind or another. 

Sometimes, however, the condition of the oil market has a most 

potent influence on the production by causing the partial or total 

shutting off of the wells; this has been the cause of a decline in the 

production of several groups in the Puente Hills district during 1905.

a For a discussion of the physical and chemical properties of the oil of the Puente Hills, see pp. 

210-217.

Bull. .309 07 10
134 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

The yield of most wells becomes less with the lapse of time. This 

decline is generally more marked during the first few months of the 

well's life than later, when the conditions governing the flow appear 

to become more stable. PL XVII, giving the average daily yield 

by months of a group of wells in the Puente Hills district, illustrates 

graphically the common variations in the yield. The minor fluctuations in the curves are usually traceable to the sanding up or cleaning out of the wells or to other local causes.

ASSOCIATED HYDROCARBONS.

Brea and gas are the only hydrocarbons associated with the oil 

in the formations of the Puente Hills district. Brea (sand or soil 

impregnated with oil from seepages, the volatile substances having 

evaporated) is found in all of the fields. The largest deposits in 

the district are in Brea Canyon, on the south slope of which are 

considerable areas covered by the material. No practical use has 

been made of it except locally for road dressing.

Nearly all the Wells in the territory under discussion yield more 

or less gas, especially in the earlier stages of their existence. In 

some localities the gas contains a considerable percentage of hydrogen sulphide, to judge by the odor encountered in the vicinity of 

certain wells; in others the gas is of such a quality as to be used 

profitably both in the generation of power by gas engines and for 

domestic purposes. Among the companies making use of the gas 

derived from their wells are the Santa Fe, in the Olinda field, and 

the Murphy, in the Whittier field. The Santa Fe Company is said 

to use gas entirely for all purposes requiring the generation of heat 

and light on its property. Some years ago a well yielding gas 

under strong pressure was struck south of Whittier, in the western 

extension of the Coyote Hills anticline. This well never furnished

any oil, and as the gas gave out the hole was abandoned.

STORAGE AND TRANSPORTATION.

With the exception of the oil in the Olinda field, much of which is 

stored in open earthen reservoirs, most of the oil of the Puente Hills 

district is stored in circular metal tanks. These tanks are usually 

covered, and vary in capacity from 5-barrel settling tanks to storage tanks holding about 55,000 barrels. The tankage of the Whittier field is something over 200,000 barrels; that of the Puente 

field, including the Chino refinery, over 100,000 barrels; that of Brea 

Canyon approximately 85,000 barrels, and that of the Olinda field 

possibly 200,000 barrels. In addition to this, the Union Oil Company has a storage capacity of about 150,000 barrels at Norwalk, 

the center of its pipe-line system, and of 37,500 barrels at San Pedro, 

its shipping point by boat.
U. S. GEOLOG CAL SURVEY BULLETIN NO. 309 PL. XVI

 5 1900. 1901. 1902. 1903. 1904. 1905.

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CHART OF VARIATIONS IN AVERAGE DAILY YIELD OF SIX WELLS IN THE PUENTE (MIOCENE) SHALE AND SANDSTONE TERRITORY (REGION OF

LIGHT, OR 32° TO 34° OIL), PUENTE HILLS OIL DISTRICT, CALIFORNIA.
PUENTE HILLS: UTILIZATION OF THE OIL. 135

The Union Oil Company owns all the longer pipe lines in the district, with the exception of the 13-mile 3-inch line of the Puente 

Oil Company from its property to its refinery in Chino and the 3-inch 

line of the Murphy and 4-inch line of the Central oil companies 

from their wells in the Whittier field to Los Nietos, 3 miles 

farther west. The Union lines comprise 17 miles of 5-inch pipe 

from. Sail Pedro to Norwalk; 15 miles of 4-inch (some 5-inch also) 

from Norwalk to Los Angeles; 12 miles of 4-inch from Norwalk to 

Brea Canyon; 3 miles of 4-inch from Brea Canyon to Olincla, and 

4 miles of 4-inch from Whittier to a junction with the Norwalk-Brea 

Canyon line.

The oil is shipped from Olirida and Los Nietos over the Atchison, 

Topeka and Santa Fe Railway, and the Southern Pacific Company 

has connections at Whittier and Los Nietos and also at the Puente 

Company's refinery at Chino. The Union Oil Company is the only 

one shipping oil by water from this district, its loading point being 

San Pedro, which, as already mentioned, is connected by pipe line 

with Norwalk and thence with all the fields of the Puente Hills.

UTILIZATION ofc1 THE OIL.

Much the larger part of the oil produced in the Puente Hills is used 

in southern California. Some of the product, however, is exported 

and shipments have been1 made to Alaska, Washington, Oregon, Arizona, New Mexico, the Hawaiian Islands, and even to Chile. In 

Alaska the oil is used principally for the development of power for 

mining purposes, while in Washington it is coming into direct competition with the local coal, which it is supplanting for purposes of 

gas production and as a fuel. The chief uses for oil in Arizona and 

New Mexico at present are in connection with mining. In the 

Hawaiian Islands the oil is used principally for fuel in the refining of 

sugar and for the development of power needed in the irrigation systems on the great plantations. In southern California it is used for 

the following purposes, named in the order of the amount consumed: 

Fuel, illuminants, the direct development of power in gas engines, 

oiling roads, and lubricants.

A new use for oil that has been developed during the past five years 

is for the purpose of road dressing. California is virtually without 

rain for two-thirds of the year, and as a result the subject of dusty 

highways is one of paramount importance. It has been found by 

experiment that the heavy oils not only settle the dust but, if properly Applied to the road, produce a springy surface which closely 

approaches that of asphalt paving. The usual method of application 

is to scratch or break up the surface of the road to the depth of an 

inch or more, sprinkle on the oil by means of certain mechanical 

devices, and finally spread a thin coating of sand over the whole.
136 OIL DISTBICTS OF SOUTHERN CALIFORNIA.

This soon becomes packed and the volatile constituents of the oil 

evaporate, leaving a dustless, springy surface of asphalt, soil, and 

sand. Several municipalities use the oil process entirely for their city 

streets and hundreds of miles of country roads in southern California 

are treated in a similar manner., A recent judicial ruling which holds 

that the principle of road oiling is not patentable has greatly stimulated this use for the heavy oils. a

PRODUCTION.

The gross production of petroleum in the Puente Hills district from 

1899 to 1904, inclusive, was 8,241,081 barrels, as follows:

Production of oil in Puente Hills district, 1899-1905.

Barrels.

1899.......'................. 217,599

1900........................ 511,550

1901........................ 909, 588

1902 ........................ 1, 728,' 962

Barrels. 

1903 .......................'. 2, 545, 318

1904........................ 2, 328,064

1905........................ 2,007,021

These figures were compiled from data furnished by the officers of 

all the producing companies. Previous to 1899 the oil produced in 

this district came almost entirely from the Puente field.

PRICES.

The Union Oil Company has furnished the following table, showing 

the average price per barrel paid for crude oil (average gravity 

18°-19° B.) at the wells in the Puente Hills district:

Average price per barrel, in cents, paid for crude oil at the wells, Puente Hills district.

July..........................................................

Average for year. ................. i .....................

1901.

80

1902.

80

80

35-40

40

40

60

1903.

' 49

53

53

44

50

54

55

56

55

63

53

1904.

60

56

57 '58

56

59

57

59

56

55

55

57

1905.

44

53

48

43

45

43

42

46

a For a detailed description of the road-oiling process see Prutzman, Paul W., Production and use ol 

petroleum in California: Bull. California State Mining Bureau No. 32, 1904.
PUENTE HILLS: OIL . COMPANIES. 137

OIL COMPANIES IN PUENTE IIII/LS DISTRICT.

The following list gives the names of the companies that have put 

down wells in the different fields of the Puente Hills district, with the 

number of wells drilled by each. Those marked with an * are not 

operating.

Companies and number of wells in Puenle Hills district, 1905.

Name of company.

Bulla *. ........................................................

li'nct Whittior *

Fidelity

H olden r .......................................................

North \V hittier *...........................;...................

Olinda Crude* . ................................................

Palo A I to ......................................................

Palo Solo*....... ..............................................

Whittier Crude. . ...............................................

Whittier G rand *...............................................

Field.

Whittier...................

.....do......................

.....do......................

Chino.......................

Olinda......................

Whittier...................

.....do......................

.....do......................

Olinda. .....................

.....do......................

.....do......................

Whittier....................

Whittier...................

Whittier...................

Whittier...................

.....do......................

(?)

Whittier...................

Olinda. .....................

.....do......................

Whittier................... .....do..........:...........

.....do......................

Whittier...................

.....do......................

.....do......................

.... .do. .................. ... 

.....do......................

.....do....................... .....do..:...................

Number 

of wells.

20

1

3

40

3

4

12

2

9

12

10

1

18

1

18

1

1

1

2

21

3

2

(?)

1

(-)

05

28

49

3

1

8

30

9

8

2

9

2

1

1

1
THE LOS ANGELES OIL DISTRICT, SOUTHERN 

CALIFORNIA.

By RALPH AENOLD.

INTRODUCTION.

During the summer of 1902 Mr. George H. Eldridge spent about two 

weeks in the vicinity of Los Angeles collecting data concerning the 

geology and oil production of the region, but'owing to poor health for 

a long time previous to his death in 1905 he had done little toward 

working this information into a report. Since Mr. Eldridge's visit the 

city field has been considerably modified by the abandonment of many 

wells and the present state of development of the Salt Lake field has 

been brought about. It has therefore been necessary to make a new 

and more detailed examination of the same region in. order to prepare a 

suitable report.

ACKNOWLEDGMENTS.

The writer wishes to fully acknowledge the value of Mr. Eldridge's 

notes, which have been freely used and which have contributed largely 

to whatever of value there may be in the following pages. Acknowledgments are due also to the various oil companies and their managers, as well as to individual drillers in the district, for assistance in 

various ways and for information- given by them during the course of 

the work. Thanks are due more particularly to Mr. E. J. Eginton, 

superintendent of the Clark Oil Company; to Mr. A. F. Gilmore, of the 

Gilmore Oil Company; and to Mr. W. W. Orcutt, geologist of the 

Union Oil Company.

PREVIOUS KNOWLEDGE OF THE REGION.

After the researches of. William P. Blake and Thomas Antisell, geologists accompanying the Pacific Railroad exploring expeditions, who 

visited southern 'California in 1853 and 1855, respectively, and of 

J. D. Whitney, State geologist, who went over portions of the same 

territory in the early sixties, no important geologic investigations in 

the region of Los Angeles or in the southern California oil fields in

138
LOS ANGELES DTSTRTCT : PREVIOUS REPORTS. 139

general were carried on until 1894, when W. L. Watts began a study 

of the petroleum deposits for the California State mining bureau.

Blake was the pioneer geologist in this region and his observations a 

are wonderfully accurate in view of the difficulties under which he and 

his associates worked. The part of his report relating to the southern 

California oil fields is that describing the region of the route traveled by 

his party, from San Francisquito Pass, north of Saugus, southward 

through Fernando Pass to Los Angeles and thence eastward to San 

Bernardino. He describes the east end of the Santa Susan a Mountains, mentions Tertiary fossils found in Fernando Pass, and speaks 

of the eruptive rock (basalt) which outcrops in Cahuenga Pass. 

About 5 miles northwest of Los Angeles he found some "light-colored 

shales, thinly stratified, and charged with bitumen, which formed 

black and brown seams between the layers," b and correlated them 

with the Miocene, shale found in the vicinity of Monterey. Blake's 

only observations bearing directly on the oil question refer to the 

bitumen which he noticed exuding from the light-colored shale, and 

are as follows:';

These places are known as tar springs, or pitch springs, and some of them form large 

ponds or lakes. One of the springs was passed on our way to the city, and was near the 

outcrop of bituminous shale in the banks of the creek already described. This spring 

was nothing more than-an overflow of the bitumen from a small aperture in the ground, 

around which it had spread on all sides, so that it covered a circular space about 30 feet 

in diameter. The accumulated bitumen had hardened by exposure and its outer portions were mingled with sand, so that it was not easy to determine its precise limits. It 

formed a smooth hard surface like a pavement, but toward the center it was quite soft 

and semifluid, like melted pitch. The central portion of the overflow was higher 

than its margin; and it was evident that all the hard portion had risen in a fluid state 

and by the heat of the sun had been gradually spread out over the surface; at the same 

time being constantly exposed to dust, it had become so thoroughly incorporated with it 

that the compound had all -the consistency of an artificial mixture. Tufts of "salt 

grass" were growing in some of the hollows and crevices of the outer portions of the 

hardened bitumen.

During the winter of 1854-55 an exploring party under the direction of Lieut. John G. Parke, accompanied by Dr. Thomas Antisell, 

geologist, examined the Santa Susana and Santa Monica ranges and 

the region adjacent to them as far east as San Bernardino. The results 

of this examination are set forth in Parke's report,6' one chapter 

dealing with the geology of the two and another with the plains of 

San Fernando, Los Angeles, and San Bernardino. By far the most 

interesting chapter bearing on the oil question in Antisell's report is 

that on "Bituminous effusions," which gives a brief summary of all 

the then known bitumen deposits in the State. The following notes 

concerning the Los Angeles region are copied from this chapter : d

"Pacific Railroad Report, vol. 5, pt. 2, 185f>, pp. f>5-8S. 

6 Op. cit., p. 70.

cPacific Railroad Report., vol. 7, pt. 2, 1857, pp. 75-86. 

dOp. cit., pp. 112-113.
140 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

Deposits of Los Angeles Valley. . . . The asphalt is protruded through these 

strata near its contact with the argillite, forming distinct wells or springs, which overflow. The land where they lie is owned by Captain Dryden,a who at the time of the 

visit was sinking a pumping apparatus for hoisting up the bitumen, which is very liquid at this locality, where it forms a small pond a fourth of a mile in circumference, 

thinner in the center than at the edges. Like the other varieties, it readily dries and 

forms a solid pavement some yards around the edge of the wells. A large quantity is 

occasionally raised and sold at the rate of 40 gallons for $5 $1 for 8 gallons. It is in 

some demand for flooring and roofing'. The quantity drawn at present seems to have 

no effect in diminishing the supply, but as intervals of rest occur, owing to the limited 

demand, it is difficult to say what continuous supply could be derived from this source. 

Mr. Trask, in his report (Doc/No. California, session 1855), calculates the amount of 

asphaltum in the counties of Santa Barbara and Los Angeles as not less than 4,000 tons. 

As he only mentions two localities, that near the village of Santa Barbara and this at 

the pueblo Los Angeles, it is presumed he reckons these as the only sources of his estimate. He does not state what the data of the calculations are. The actual quantity 

already poured out on the Santa Barbara shore is vastly greater than at Los Angeles 

^perhaps 6,000 tons would be an underestimate for Santa Barbara, but as a source of 

asphaltum it is extinct, while that at Los-Angeles is actively pouring out, although the 

accumulated overflow is much smaller. As a locality of asphaltum available for the 

present time, Santa Barbara is preeminent; as .a source for future wants, Los Angeles is 

preferable. By following the line of upheaval on these hills and making borings in the 

sandstone strata, the bitumen might be reached, and thus other sources than the 

natural well might be drawn upon. Doctor Trask values the asphaltum delivered in 

San Francisco at $16 per ton, but this is an excessive valuation according to the price 

at the well or according to the calculations of freight from Santa Barbara northward. 

Allowing the value to be $7 per ton, and in Los Angeles Valley about 2,500 tons to 

be at present available, the actual present wealth of the valley in bitumen would 

be $17,500. This, of course, does not take into account the future supply.

In addition to the descriptive matter Antisell gives a geologic section across the Santa Monica and Santa Susana ranges and another 

from San Pedro through Los Angeles to San Fernando. 6

J. D. Whitney, State geologist from 1860 to 1874, describes the 

region from the San Fernando Valley north to the Bay of Monterey, c 

and in the same chapter enters into a discussion of the probabilities 

of finding oil in the Tertiary rocks of the Coast Range. He also 

severely arraigns the promotors of " wild-cat" oil companies, which, 

at the time of writing the report (1865), were preying on the credulous public. Another chapter is devoted to the geology of the Santa 

Monica and San Gabriel ranges and the vicinity of Los Angeles. The 

following are Whitney's notes concerning the brea deposits in what 

is now the Salt Lake field: d

About 7 miles due-west of Los Angeles is the most important of the numerous tar 

springs seen in this vicinity. It is from here that most of the asphaltum used in the 

town is obtained. Over a space of 15 or 20 acres the bituminous material (which, 

when seen by us, in.the winter, had exactly the consistency and color of tar) was oozing

a The "old Dryden well" is located about three-eighths rnile north-northwest of Westlake Park. 

b Pacific Railroad Kept., vol. 7, pt. 2, 1857, PI. V, figs. 2, 3. 

c Geol. Survey California, Geology, vol. 1, 1865, pp. 108-160. 

4 Op. cit., pp. 174-175.
LOS ANGELES DISTRICT: PREVIOUS REPORTS. 141

out of the ground at numerous points. It hardens on exposure to the air and becomes 

mixed with sand and dust blown into it, and is then known as "brea." The holes 

through which the bitumen comes to the surface are not large, few being more than 3 

or 4 inches in diameter. On removing the tarry substance from the holes, by repeatedly 

inserting a stick, the empty cavity was very slowly filled up again. At one place there 

was a pit several yards square and 6 v or 8 feet deep, from which the tar had been taken, 

but it was filled with water at the time of our visit in consequence of late heavy rains. 

The brea is used almost exclusively for covering roofs at Los Angeles, selling (in 1861) 

at the springs for $1 per barrel, the purchaser collecting it himself, which is done by 

digging a pit 2 or 3 feet deep by the side of one of the holes from which the tar is issuing 

and letting it fill up. A very large amount of the hardened asphaltum, mixed with 

 sand and the bones of cattle and birds, which have become entangled in it, lies scattered over the plain. Before I860 the experiment of shipping it to San Francisco for 

the purpose of distilling burning oil from it had been tried, without success, at least 

in a pecuniary point of view.

A report on the geology of a portion of southern California, by 

Jules Marcou ; a a paper on the petroleum, asphaltum, and natural 

gas of California, by W. A. Goodyear,6 and a paper on the origin, 

composition, etc., of California petroleum, by F. Salathe, c complete 

the list of more or less important papers bearing on the geology and 

oil industry of the region about Los Angeles up to 1897.

In 1897 W. L. Watts issued the first d of his two reports largely 

devoted to the Los Angeles and adjacent oil districts. In this report 

he gives a brief outline of the geology of the territory discussed; lists 

and logs of productive, test, and abandoned wells, and' notes on 

miscellaneous subjects, such as fossils of the oil-bearing formations, 

production, uses, and chemical and physical properties of the oil, 

refineries, drilling machinery, etc. Watts's second report,6 although 

covering the California oil districts in general, is still largely given over 

to the fields of Los Angeles, Ventura, and Orange counties. Chapters 

are devoted to a discussion of the structural conditions pertaining to 

the occurrence and distribution of petroleum in California, the uses 

and chemical and physical characters of the oil, etc., and in addition 

there are brief reports on the .fossils of the oil-yielding formations by 

J. C. Merriam, on the Humboldt County oil fields by F. M. Anderson, 

and on the oil-yielding formations of San Luis Obispo and Monterey 

counties by H. W. Fairbanks.

A paper by G. H. Eldridge/ in the Contributions to Economic 

Geology for 1902, is of interest not only on account of its comprehensive 

though short description of the individual fields, but also because it

a Ann. Kept. U. S. Geog. Surv. W. 100th Mer., 1876, Appendix H 1, pp. 158-172.

'> Seventh Ann. llept. California State Minaralogist, 1838, pp. 63-114.

^Thirteenth Ann. llept. California Stat3 Mineralogist, 18J6, pp. 656-661.

<*OH and gas yielding formations of Los Angeles, Ventura, and Santa Barbara counties: Bull. California State Mining Bureau No. 11, 1897, pp. x-t-94, 35 Figs. .

t Oil and gas yielding formations of California: Bull..California State Mining Bureau No. 19, 1900, pp. 

236, 26 text figs., 35 half tones, 13 maps.

/The petroleum fields of California: Bull. U. S. Gcol. Survey No 213, 1903, pp. 306-321.
142 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

alone contains in epitomized form a number of the conclusions of this 

eminent authority regarding the California fields as a whole. A 

brief description of the Salt Lake field is given by the writer a in Contributions to Economic Geology for 1905.

A most useful bulletin relating to the technical and commercial 

phase of the oil question by Paul W. Prutzman b gives maps and 

other brief data in regard to the principal oil districts, together with 

detailed information concerning the character of the oil and its uses 

for fuel, for oiling roads, etc.

A short bibliography of the principal papers relating to the geology 

and technology of the Los Angeles and adjacent oil districts and to the 

oil industry of California is given on pages 199-202 of this report.

LOCATION AND TOPOGRAPHY.

The Los Angeles district, comprising the productive oil fields immediately north and west of the city, is located from 15 to 20 miles from 

the coast in the central part of southern California. Three transcontinental railroads the Southern Pacific, the Atchison, Topeka and 

Santa Fe, and the San Pedro, Los Angeles and Salt Lake pass 

through it, and steamers touch at Port Los Angeles, Redondo, and San 

Pedro, its ports of entry.

The city of Los Angeles occupies an area of about 15 square miles, 

the greater portion lying west of Los Angeles River at its debouchment from the low hills, which to the west pass gradually into the 

Santa Monica Range and to the east and north into the San Rafael 

Hills and Verdugo Mountains. To the southeast are the Raphetto 

Hills, which with the Puente Hills farther southeast constitute the 

connecting link between the Santa Monica and Santa Ana ranges. 

The Elysian Park hills north of the city trend northeast and southwest. Their southwestern slope is gentle and extends into the great 

Los Angeles-Santa Monica plain. Their northeastern slope is abrupt 

and parallels Los Angeles River. Northwest of the Elysian Park hills 

is the eastern extension of the Santa Monica Mountains, somewhat 

isolated from the main range by Cahuenga Pass, which trends northwestward from Hollywood, a suburb of Los Angeles. The mountainous 

area east of Cahuenga Pass is cut into sharp ridges and deep canyons 

and culminates in Cahuenga Peak at an elevation of 1,825 feet.

a. The Salt Lake oil field, near Los Angeles, Cal.: Bull. U. S. Geol. Survey No. 285, 1000, pp. 224-226, 

fig. 9.

b Production and uses of petroleum in California: Bull. California State Mining Bureau No. 32, 1904, 

pp. 230, 64 figs.
LOS ANGELES DISTRICT : GEOLOGIC FORMATIONS. 143

North of the Santa Monica Range lies the San Fernando Valley, 

separating this range from, the Santa Susana Mountains on the north. 

South of the Santa Monica Range and the Elysian Park hills is the 

broad Los Angeles-Santa Monica plain, which slopes gently southward to the Inglewood hills, southwest of Los Angeles. A physiographic feature which appears to reflect in a general way the underlying structure and if so may be important in determining the location of the productive territory is the gentle declivity extending 

from the middle of the Salt Lake field northwestward toward Sherman.

GEOLOGIC FORMATIONS.

Tentative, correlation of oil-bearing formations of southern California with the standard

California geologic section.

Period.

Cenozoic.

Mesozoic.

System.

Quarternary.

Tertiary.

Creta- ceous.

Jurassic.

Scries.

Recent.

Pleistocene.

Pliocene.

Miocene.

(

Oligocene

Eocene.

'\

Standard California section.

Alluvium.

San Pcilro.

Merced .

Purisima.

San Pablo. 

 Unconformity 

Montcrey.

Vaqueros.

San Lorenzo.

Tcjon. 

Mart Inez. 

 Unconformity? 

Chico. 

Horse town. 

ICnoxville.

Granitic rocks of 

the Sierra Nevada.

Santa Clara 

valley.

Alluvium.

Sand and gravel.

Fernando.

 Unconformity 

. Shale. 

 2 Upper sand- 

 O' stone. 

5 Lower sand- 

** stone.

Vaqueros.

o> [Upper. 

&J Lied beds. 

$ [Lower.

Topatopa. 

(?)

Granitic rocks of 

the San Gabriel 

Range.

Los Angeles.

Alluvium.

Sand and gravel.

Fernando.

 Unconformity 

Diabase intrusion.

3 [Upper shale. 

g< Sandstone. 

3 (.Lower shale.

(?)

 Unconformity 

Granitic rocks of 

the Santa Monica Range.

Black schist.

Puente Hills.

Alluvium.

Sand and gravel.

Fernando.

 Unconformity 

Diabase intrusion

2 (Upper shale. 

§ { Sandstone. 

s 1 Lower shale.

OH 

(?)

%
144 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

GENERAL STATEMENT.

The formations involved in the geology of the region about Los 

Angeles consist of (a) black micaceous schist; (&)' a granitic series 

embracing diorite, gneiss, and uther crystalline rocks; (c) more than 

2,000 feet of Puente sandstone of lower Miocene age; (d) about 2,000 

feet of upper Puente shale and soft, thin-bedded sandstone, also of 

Miocene age, (e) basalt and diabase intruding the previous formations, but older than the following: (/) 2,000 feet or more of soft, 

thin and thick bedded sandstone, thin-bedded shale, and heavybedded conglomerate of the Fernando formation, largely of Pliocene 

age, and (</) a capping of Pleistocene gravels and sands of variable 

thicknesses. (See fig. 12.)

Quaternary

Pliocene.

Middle (and possibly 

upper) Miocene"

Lower Miocene.

Pre-Cretaceous.

100+ Alluvium and roughly bedded gravel, sand, and clay.

2,000+

2,000±

Upper portion thick-bedded soft sandstone with a few layers of conglomerate and thin-bedded sandy shale. Lower 

portion, largely thin-bedded soft clayey sandstone and 

sandy shale, somewhat petroliferous riear the Miocene 

contact.

(Probable unconformity, beds of both formations having 

\ approximately the same dip.

Upper half, thin-bedded sandstone and sandy shale, with 

some hard siliceous members and one or two bands of 

coarse sandstone, which usually carry oil. Lower half, 

alternating bands of thin-bedded siliceous shale and 

coarse sandstone. This and all older formations intruded by diabase and basalt.

2,000+

Coarse, heavy-bedded brown arkose sandstone interbedded with minor quantities of argillaceous and siliceous shale, the shale being relatively more abundant 

toward the top and bottom of the formation. Total 

thickness unknown.

Basement complex of diorite and other granitic rocks and 

gneiss, associated with an extensive dark-colored micaceous schist.

Fig. 12. Generalized geologic section for the immediate vicinity of the Los Angeles oil fields.
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PLUTONIC IGNEOUS METAMORPHOSED SEDIMENTARY

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PLIOCENE QUATERNARY

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LOS ANGELES DISTRICT: GEOLOGIC FORMATIONS. 145 

BLACK SCHIST.

Black micaceous schist with a general northwesterly dip outcrops 

on the flanks of the Santa Monica Mountains about a mile northwest of Sherman and extends in a westerly direction along the south 

slope of the range for at least 15 miles. This schist is black to dark 

reddish brown in color, in some cases resembling certain hematite 

ores, and usually shows a very characteristic luster, due to the faces 

of the minute component mica flakes. Little is known concerning 

the age of these rocks except that they are older than the granite 

which bounds them on the east. It is certain, however, that they 

are pre-Cretaceous.and very probable that they are Jurassic.

GRANITE.

A large part of the Santa Monica Mountains from the vicinity of 

Coldwater Canyon eastward to Los Angeles River is made up of

granitic rocks similar in all respects to and probably contemporaneous with the granitic rocks which form the Verdugo hills, the 

northern part of the San Rafael hills, and the major part of the 

great San Gabriel Range to the north and east of the Santa Monica 

Mountains. In the region about Edgemont, northeast of Hollywood, the rock appears to be a fine-grained biotite granite, showing 

considerable quartz in hand specimens, although weathering precludes any exact determination of the composition. Biotite and 

hornblende granite, with some closely associated brown micaceous 

schist, appears to make up the larger portion of the crystalline area 

from Cahuenga Pass westward to Coldwater Canyon. With the possible exception of the western contact, which is probably one of 

deposition, the rock of the Edgemont area appears to be separated 

from the adjacent formation by fault planes, although the exact 

nature of the shale-granite contact north of Ivanhoe was not determined. The granite is younger than the black schist and is certainly pre-Cretaceous and probably late Jurassic in age.

PUENTE SANDSTONE.a 

GENERAL CHARACTER.

The oldest Tertiary rocks so far discovered in the Los Angeles 

area consist of a heavy-bedded sandstone which overlies the preCretaceous granite and schist on the flanks of the Santa Monica 

Mountains and makes up the bulk of the Elysian Park hills and 

the hills on the northeastern side, of Los Angeles River from Gaston 

southeastward to the hills east of Eastlake Park. The lower part 

of the formation is somewhat argillaceous and may correspond to

«See note regarding divisions of Puente formation on p. 103.
146 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

the lower Puente shale or to a portion of the Vaqueros formation, 

but the larger part is doubtless contemporaneous with the Puente 

sandstone of the Puente hills district. The best exposures of the 

Puente sandstone in the region about Los Angeles are in the Elysian 

Park hills, which are developed on the southern limb of a great 

anticline. (See PI. XXI, BJ) The formation as here developed consists of at least 2,000 feet of heavy-bedded, coarse-gray to rustyarkose sandstone, interbedded at irregular intervals with dark-colored earthy and siliceous shale. The sandstone beds vary in thickness from 1 to 12 feet. Some are uniformly hard throughout, while 

others are concretionary, the concretions usually being elliptical in 

shape and in some cases coarser grained than the surrounding rock. 

As a rule, however, the sandstone is soft and falls an easy prey to 

weathering agents, being much less resistant than the interbedded 

shale. This differential weathering is well exemplified in certain 

ridges in Elysian Park, which cut transversely across alternate layers 

of the steeply dipping sandstone and shale, the latter forming prominent knobs at its outcrops along the top of the ridge. Jointing is 

well developed in the sandstone in certain localities, notably at the 

south end of Elysian Park, where hardening along the cracks of 

three different systems forms a kind of block structure. This is 

common in similar sandstones at many places throughout the Coast 

Range. In the region west of Edgemont and also along the flanks 

of the Santa Monica Mountains west of Sherman the basal beds of 

the Puente consist of conglomerate and sandstone, with appreciable 

amounts of interbedded gray to drab shale. The pebbles and cobbles in the conglomerate consist of granite rocks, diorite porphyry, 

quartzite, etc., some attaining a diameter of 3 feet. In the region of 

the basalt intrusions and flows about Cahuenga Pass the sandstone 

appears to have been slightly baked, and is harder, more jointed, and

darker colored than in the Elysian Park hills. It may also represent 

a somewhat lower horizon than the Elysian Park rock.

FOSSILS.

The Puente sandstone has yielded fossils in several localities in 

this region. In a street cut in Pasadena on the west side of Raymond Hill, about 2 miles northeast of the corner of the area shown 

in the accompanying map (PI. XVIII) was found the following fauna:

Puente fossils from Raymond Hill, Pasadena, Cal.

Area cf. montereyana Osmont.

Chione n. sp.? (small, with prominent concentric frills).

Leda cf. taphria Ball (PL XXXVIII, fig. 5).

Panopea generosa Goulcl.

Phacoides cf. acutilineatus Conrad.

Thracia n. sp.
LOS ANGELES DISTRICT : PUENTE FORMATION. 147

Yoldia n. sp.

Agasoma barkerianuin Cooper.

Natica or Neverita sp.

Turritella cf. variata Conrad (PI. XLI, figs. 10, II, 1.2). -

Another fossiliferous locality is at Laughlins Hill, one-half mile 

southwest of Edgemont, where the following species were obtained:

Puente fossils from Laughlins Hill, north of Los Anyeles, Cal.

Card him sp. (large; sharp ribbed). .

Pecten crassicardo Conrad (PL XXXI, fig. I).

Phacoides cf. childreni.

Phacoides richthol'eni Gabb.

Neverita callosa Gabb (PL XXXI, figs. 4, 4a).

Trophon sp.

The following fauna, characteristic of the lower Miocene throughout the southern San Joaquin Valley arid as far south as the Santa 

Ana Mountains, is found at the head of Topanga Canyon, about 3 

miles south of Calabasas, at the west end of the San Fernando Valley:

Puenle fossils from 8 miles south of Calabasas, Los Angeles County, Cal. 

PELECYPODA.

Callista (Amiantis) diabloensis Anderson.

Card him sp. (sharp ribs).

Card hi m sp. (square ribs).

Chione temblorensis Anderson (PL XXX, figs, I, la).

Dosinia ponderosa Gray (PL XXXIII, fig. 4).

Glycymeris sp. (large).

Macoma cf. nasuta Conrad.

Mytilus inathewsonii Gabb var. expaiisus Arnold (PL XXX, fig. 2).

Ostrea titan Conrad (PL XXVII, fig. 2; PL XXXII, fig. 2).

Pecten bowersi Arnold (PL XXVII, fig. .1).

Pecten cf. miguelensis Arnold.

Phacoides richthpfeni Gabb (PL XXXII, fig. 4).

Venus pertenuis Gabb.

GASTEROPODA.

Agasoma cf. kerniauum Cooper. 

Bitthim sp. 

Calliostoma sp.

Cancellaria cf. con don i Anderson (PL XXVII, fig. 9). 

Cerithium topangensis Arnold (PL XXVII, figs. 7, 8).

* Chlorostonia (Ornphalius) clalli Arnold (PL XXVII, figs. 4, 4a, 4b, 5, 6, 6a). 

Cylichna sp.

Dolichotoma keepi Arnold (PL XXXIII, fig. 5). 

Drillia sp. 

Fusus sp.

Macron merriami Arnold (PL XXVIII, figs'. 4, 4a). 

Neverita callosa Conrad (PL XXXI, figs. 4, 4a). 

Ocinebra topangensis Arnold (PL XXX, fig. 4). 

Purpura edniondi Arnold (PL XXVII, figs. 3, 3a). 

Sigaretus perrini Arnold (PL XXVIII, fig. 5).
148 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

Trochita costellata Conrad (PL XXXII, fig. 3).

Trochita cf. inornata Gabb.

Trophon sp.

Turbo topangensis Arnold (PL XXVIII, fig. 6).

Turritella ocoyana Conrad (PL XLI, figs. 7, 8, 9).

Turritella variata Conrad (PL XLI, figs. 10, 11, 12).

The above fossils indicate that the beds in which they occur are of 

lower Miocene age and probably equivalent in general to the Vaqueros 

sandstone of central California.

UPPER PUENTE SHALE. 

GENERAL CHARACTER.

Above the massive-bedded Puente sandstone and grading into it 

is a mass of strata at least 2,000 feet thick, in which shale beds of 

one sort or another largely predominate. No "sharp line of demarcation separates this shale from the sandstone beneath, but as a whole 

they are radically unlike. The two members are differentiated on 

the map (PL XVIII) along a line which, it is thought, marks the 

boundary between the preponderance of the sandstone facies on the 

one hand, and the preponderance of the shale on the other. The shale 

in the region north of Los Angeles may be roughly divided into two 

approximately equal parts, the lower 1,000 feet consisting of broad 

bands of thinly laminated white to gray shale interbedded with 

similar bands of more or less thick-bedded, coafse yellowish to brown 

sandstone, and the upper 1,000 feet or more being characterized by 

thin-bedded sandy and clayey shale and thin to medium bedded 

sandstone. At the top of the shale series is a band of thin-bedded 

hard white siliceous shale, interstratified with 2 to 4 inch layers of 

brown sandstone. The top of this band is used in mapping as the 

arbitrary line between the Puente formation and the overlying Fernando (Pliocene) sandstone.

Most of the shale in the lower part of the member, and also many 

of the shale beds interstratified with the Puente sandstone, are of the 

hard white siliceous variety characteristic of the Monterey shale in 

the Coast Range. This shale splits easily along the bedding planes 

into thin, sharp-cornered plates. Fragments of these scales or plates, 

which are very resistant to weathering, are often found scattered 

over the ground and thus indicate the presence of the beds over areas 

in which outcrops may be rare. Abundant minute organic remains 

are usually found in the siliceous layers, but no recognizable molluscan forms have so far been obtained from them in this.region. In 

the territory northeast of Los Angeles the structure is complex and 

an exact determination of the position of the shale is impossible; but 

it is probable that most of it belongs to the upper part of the Puente 

formation. In the vicinity of Sycamore Park the rock consists of
LOS ANGELES DISTKICT : PUENTE FOBMATION. 149

at least 400 ,to 500 feet of very dark colored, highly carbonceous, 

thinly laminated gypsiferous shale, showing traces of sulphur on the 

weathered surfaces. Associated with this is dark-brown sandy shale", 

interstratified with yellowish limy layers containing gray to yellowish 

calcareous elliptical concretions as much as 5 feet in length. Thinbedded white chalky shale containing numerous fish remains is also 

found a little to the southwest of Sycamore Park. In the region 

about the mouth of Cahuenga Pass, where the shale is intruded by 

diabase, it is much contorted and fractured, gray to discolored blue 

gray and rusty brown in color, in places gypsiferous, and much of it 

tending to concretionary structure.

The upper 1,000 feet or more of the upper Puente shale consists 

principally of soft, .thin-bedded clayey to sandy shale, varying in 

color from gray through light yellow to rusty brown and locally, 

where oil bearing, to bright tints of yellow and pink. A peculiar 

efflorescence characterizes the weathering of the sandy members of 

these upper beds in many places. At the top of the formation are 

two bands of thinly laminated, alternating hard fvhite and soft drab 

shale, separated by about 125 feet of coarse sandstone, the latter 

being shown on the map (PI. XVIII) by a special legend. These two 

shale bands, with their interbedded and underlying thin-bedded 

sandstone, mark the principal oil-bearing zone in the Los Angeles 

district.

Associated with the shale at the top of the lower half of the upper 

Puente shale is a 50-foot band of coarse arkose sandstone, which is 

shown on the map in the same color as the Puente sandstone.

OIL SANDS.

As mentioned in the preceding section, the productive oil sands 

occur interbedded with the shale near the top of the Puente formation. Exposures of these sands are to be found almost continuously 

along the mapped oil-sand zone, running from the Sisters' Hospital, 

on Sunset boulevard, to the bend in the Hollywood and Cahuenga 

Valley Railroad, on Western avenue. The surface exposures of the 

upper sands, which aggregate about 125 to 150 feet in thickness, usually either are more or less impregnated with oil or asphaltum or else by 

their color show the effects of its former presence in the beds. These 

sands vary in color from brown to dark drab and in some instances 

show bright tints of pink, purple, and yellow. As a rule they are 

coarse and in places, notably toward the west end of the district, 

they are more or less finely conglomeratic. The concretionary tendency is also characteristically shown in certain of the beds. In the 

low hilly region flanking the Elysian Park hills on the west what is 

supposed to-be the equivalent of a part of the oil sands is characterized by large, hard concretions. (See PI. XXI, A.) At one place

Bull. 309 07 11
150 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

these concretions are round, while at others they vary from elliptical 

to irregular; they are usually 4 feet or less in diameter. In some of 

the layers of this band the grains of quartz and feldspar attain a 

diameter of three-eighths of an inch, in others the grain is finer. 

The color of the sands here "varies from gray through light yellow to 

purple, the latter color indicating the former presence of oil in the 

rock.

About 300 feet stratigraphically beneath the upper oil sands is the 

second productive layer. This consists of 40 to 50 feet of thick to 

medium-bedded arkose strata, similar in all practical respects to the 

upper sands. Between these two principal layers and in the shale 

beneath the lower are other sandy beds, which are shown by the well 

records in the west end of the field to be more or less productive. 

The great bulk of the oil, however, is derived from the two principal 

layers just described.

MIOCENE BASALT.

Large masses of4>asalt are associated with the Puente sandstone 

and shale in the region about the mouth of Cahuenga Pass and to the 

east as far as Laughlins Hill. From evidence to be obtained at different localities in this region, both intrusive masses and surface flows 

are represented by the rock. Outcrops of a spheroidal type, such as 

that forming the little knoll three-fourths of a mile northwest of Hollywood, indicate the intrusions^ while the vesicular facies found in the 

east end of Laughlins Hill tends to prove the existence of the flows. 

The usual color of the weathered outcrops is purplish red to reddish 

brown, the overlying soil in nearly all cases partaking of the characteristic color of the underlying rock. The igneous rock in the knoll 

three-fourths of a mile northwest of Hollywood, although doubtless 

genetically identical with the fine-grained basalt lying farther east, 

somewhat resembles in hand specimens certain forms of diabase.

The age of the basalt is the same as that of similar rocks found north 

and northwest of Santa Monica in the Santa Monica Mountains, also 

in the Puente Hills, north of Brea Canyon, and in many regions of the 

Coast Range at least as far north as the Santa Cruz Mountains. The 

rock intrudes or is interbedded with the Vaqueros sandstone and Monterey shale or contemporaneous formations at one locality or another, 

but is unknown, except as worn pebbles in conglomerate, in any of 

the later formations. It is therefore of middle Miocene age.

FERNANDO FORMATION. 

GENERAL CHARACTER.

The line of demarkation between the Miocene and Pliocene formations in the region about Los Angeles is not at all distinct. There is 

no doubt of the existence of a decided break between the white shale
LOS ANGELES DISTKICT : FERNANDO FORMATION. 151

of the Miocene and the upper fossiliferous sand and conglomerate of 

the Pliocene, represented by a period of deformation and subsequent 

erosion. Just what plane in the stratigraphic sequence of beds marks 

this period, however, has not been determined. The interbedded 

conglomerate found in the fossiliferous lower Pliocene sandstone contains numerous waterworn and pholas-bored fragments of the characteristic white Miocene shale, and this evidence clearly proves the conditions of a break or unconformity. A marked unconformity is 

usually discernible between the Monterey shale and subsequent formations at most places throughout the Coast Range where the two 

formations are in contact, so that it is not at all surprising to meet this 

evidence here. Over many areas, both north arid south of the Los 

Angeles district, similar evidence is corroborated by the presence of 

marked structural unconformities. Here this latter1 evidence appears 

to be lacking.

It is necessary, therefore, to draw an arbitrary line separating the 

two formations. Because of the almost complete absence of the hard 

white siliceous shale from the Pliocene (Fernando) the line separating 

the Miocene (Puente) and the Pliocene (Fernando) has been drawn at 

the top of the uppermost layer of hard, white shale. This line is probably somewhat lower than if it were drawn on paleontologic evidence. 

In other words, the lower part of what is here termed the Fernando 

formation (Pliocene) is possibly Miocene and may be contemporaneous with some portion of the San Pablo (upper Miocene) of central 

California. 

The basal portion of the Fernando formation consists of about 500 

feet of soft to compact, thin-bedded sandstone and sandy shale,- with 

some zones in which the shale is fine grained and clayey. (See PI. 

XXIV, A.) The, color of the beds ordinarily varies from gray and 

light yellow to rusty brown, except in those strata that are or have 

been impregnated with oil, many of which are chocolate, purple, or 

bright yellow. Above the purely sandy strata is a zone about 500 feet 

thick in which some of the shale is calcareous and very hard. Some of 

this hard shale, especially that which shows a tendency to concretionary structure, closely resembles certain of the Miocene shales. 

This zone of calcareous shale is also rich in gypsum, some of the veins 

being 2 inches wide. Most of the veins occur between the bedding 

planes of the shale, although some cut the strata transversely.

Above the shaly portion of the Fernando are thick-bedded, soft 

gray to light-yellow sandstone and coarse conglomerate associated 

with some thin-bedded bluish-gray sandy shale or shaly sandstone. 

The thin beds of conglomerate in this portion of the formation. are 

those already mentioned as being composed largely of waterworn and 

pholas-bored fragments of the siliceous Puente shale. This conglomerate, as well as the sandstone and sandy shale, yields a characteristic
152 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

lower Pliocene marine molluscan fauna. The thickness of the upper 

part of the formation is somewhat problematical, although the evidence at hand shows that it is 1,000 feet or more, making the total 

thickness of the Fernando over 2,000 feet.

The areal distribution of the formation is most interesting when 

considered in its relation to the Puente-. In the region of the oil belt 

the Fernando rests upon the uppermost Puente white shale in a great 

southward-dipping monocline. East of the oil belt and Los Angeles 

River this simple relation seems to be changed. Here, in the meager 

exposures afforded by rare gaps in the Pleistocene and alluvium 

deposits, occur what appear to be the lower, thin-bedded sandstone 

and sandy shale of the Fernando in contact with the Puente sandstone, the white, shale apparently being absent through the agency 

either of an unconformity or of a fault, or of both combined. The 

Fernando also extends southeastward to San Gabriel River, pomprisirig the bulk of the sediments of the Raphetto hills, the west end of 

which is shown on the map. (PI. XVIII.)

FOSSILS. <-. 

The following fossils were obtained by Homer Hamlin from the 

Third street tunnel in Los Angeles and indicate the lower Pliocene age 

of at least this part (upper sandstone, sandy shale, and conglomerate) 

of the Fernando formation:

Lower Pliocene fossils from the Fernando beds in the-Third street tunnel, Los Angeles.

Area multicostata Sowerby (PI. XXXVIII, fig. 1). 

Astarte sp. 

Lima hamlini Dall. 

Macoma sp. indiv.

Ostrea veatchii Gabb (PL XXXIX, fig. 1). 

.Pecten ashleyi Arnold (PI. XXXIV, fig. 2). 

Pecten latiauritus Conrad (PL XXXVI, figs. 2, 3). 

Pecten opuntia Dall (PL XXXVI, fig. 8). 

Pecten pedroanus Trask (PL XXXVI, figs. 5, 6). 

Pecten stearnsii Dall (PL XXXV, fig. 2). 

Buccinum sp. indet.

Fissuridea murina Carpenter (PL XL, figs. 3, 3a). 

Nassa hamlini Arnold (PL XL, fig. 9). 

Neverita recluziana Petit (PL XXXVIII, fig. 6). 

Pleurotoma sp. indet. 

Priene oregonensis Redfield var.?angelensis Arnold (PL XL, fig. 11).

The following is a list of fossils collected by W. L. Watts in the 

vicinity of Los Angeles and largely identified by J. G. Cooper : a

a Bull, California State Mining Bureau, No. 11,1897, pp. 79-81.
LOS ANGELES DISTRICT: PLIOCENE FOSSILS. 153

Pliocene fossils from Los Angeles and vicinity.

Name.

Cancellaria tritonidea Gabb ...............

Chama exogyra Conrad. . .................

Corbula luteola Carpenter. ...............

Cryptomya californica Conrad ...........

Drillian. sp. (?).............. ...........

Diplodonta orbella Gould ................

Laqueus californicns ? Koch .............

Ocinebra lurida MiddendorfT. ............

Oxyrhina plana Agassiz. .................

Saxidomus gibbosus Gabb ...............

Sernelo decisa Conrad .....................

Tellina idea Ball ............. . ..-.. . .

Terebratalia occide'ntalis Ball ...........

Angeles oil Los

wells.

v

v

X

V

v

y

Green- Wllon

Meadow ranch.

X

X

v

X

West Shatto estae, Los Angeles.

X

X

X

X

V

V

X

school, Normal Los

Angeles.

X

V

X

X

X

X

X

V

V

V

v

v

V

Other localities.

\

^

Reynolds & Wiggins well, Los Angeles.

geles.

geles.

geles.

PLEISTOCENE. 

GENERAL CHARACTER.

The Pleistocene deposits in the Los Angeles region comprise gravel, 

sand, and clay, the first mentioned predominating. ' The gravel and 

sand capping the Fernando in the region of the oil belt and farther 

south, especially on the top of the ridge on-which the normal school 

is situated, are probably of marine origin; the rest of the deposits are 

largely fhiviatile.
154 OIL .DISTRICTS OF SOUTHERN CALIFORNIA.

The thickness of the Pleistocene, especially along the southern 

edge of the area mapped, is probably 300 to 500 feet, while in certain of the terrace deposits, such as those on the hills north of Sherman and on the terraces flanking Los Angeles River and Arroyo Seco, 

it may be only from a few inches to, say, 50 feet.

BREA DEPOSITS.

In the region immediately northwest of the Baptist College, in the 

territory one-half to three-fourths mile southwest of Colegrove and 

on the south side of the Rancho la Brea the Pleistocene and alluvial 

deposits are impregnated with asphaltum, forming brea. This material originates in two ways heavy oil or asphaltum exudes from the 

surface and becomes filled with drifting dust and sand, or the fluid 

exuding from the underlying hard strata impregnates overlying 

porous gravel and sand. Details concerning the brea deposits are 

quoted under the heading " Previous knowledge of the region," the 

older geologists having had an exceptional opportunity for studying 

these "tar springs," which at the time of their visits were almost 

untouched and much more extensive than at present. In the Rancho 

la Brea deposits at the south side of the Salt Lake oil field many bones 

of extinct mammals have been found. (See PI. XXIV, B.) The following notes concerning these remains are quoted from an unpublished manuscript by Dr. J. C. Merriam:

The beds in which the bones occur extend over many acres. So far as I am aware 

the bottom has not been reached irTexcavations carried on to the depth of at least 15 

feet in quarrying the asphalt. Bones are scattered through a large part of the deposit, 

but are very unevenly distributed. In some localities they are present in large numbers and in fairly defined layers.

The asphalt has in many cases penetrated even the minute pores of the bone, but 

the original material of the skeleton is itself practically unchanged.

The remains recognized up to the present include the following: Elephas, Equus, 

Bison, Mylodon (t),.Smilodon, Canis indianensis (?),. Canis small species and camel 

remains. Numerous bird bones and remains of insects arejlso found.

In a considerable number of cases large parts of the skeleton are found together, 

showing that the carcasses were entombed so quickly that there was not sufficient 

time for decomposition to permit separation of the parts.

Of the remains recognized up to the present time, an extraordinarily large percentage represents Carnivora. The number of carnivores is certainly relatively larger than 

the usual percentage in a well-balanced fauna, and this abundance must be attributed 

to peculiar conditions under which the bones accumulated. Undoubtedly most of 

the remains are those of animals that have- been entrapped or mired in the asphalt at 

times when it formed a sticky deposit around tar springs. The surface of the asphalt 

is very sticky in some places at the present time, and where cuts are opened in it tar 

may ooze out. Such pools have probably existed here interruptedly through a long 

period, and particularly during Quaternary time when the deposit was forming. 

Carnivores are numerous, because they were attracted by birds and mammals caught 

in the asphalt. Perhaps it is not entirely a coincidence that the carnivore remains are 

usually associated with those of birds or mammals, which would be their natural prey. 

The considerable number of young saber-tooth cats present may indicate that the 

younger and less experienced individuals were more easily lured into the tar pools.
LOS ANGELES DISTRICT: STRUCTURE. 155

Aside from their scientific value, these bones have the added significance of indicating that the brea-forming conditions which are 

now prevalent in this field were in operation during a large portion 

 of Pleistocene time. In view of the great number of years during 

which the gas and oil have been escaping in this field, it seems rather 

remarkable that such prolific deposits of petroleum are still to be 

found in the underlying strata. These, facts indicate the almost 

^incomprehensible amount of oil that was originally contained in the 

Tertiary rocks over certain areas of the Coast Range belt.

STRUCTURE.

GENERAL FEATURES.

The structural features in the region about Los Angeles are dependent on two systems of disturbances. The older of these consists primarily of folds, with which are usually associated minor faults. This 

system dominates the Miocene strata and was probably largely developed during the post-Puente (late middle Miocene) readjustment, 

which had such a widespread effect throughout the Pacific coast of 

the United States. The axes of disturbance of the Miocene system 

trend, approximately, N. 60° W. The younger system, in which 

faults are apparently the dominant features, was developed during 

late Pleistocene time and affects all the formations in the area. The 

general trend of the axes of the Pleistocene system is east and west. 

Minor faults with planes striking in various directions are common 

throughout the-district.

The most prominent structural feature in the district is the great 

flexure in the Puente sandstone and shale which lies northeast of the 

business portion of Los Angeles and trends N. 60° W. This will be 

referred to as the Elysian Park anticline. (See PI. XX, sec. E-F.) 

This anticline might almost be regarded as an elliptical structural 

dome, as it appears to plunge at both its northwest and southeast 

ends. Not far from the northwest extremity of the anticline where 

it approaches the fault zone lying along the southern base of the 

Santa Monica Mountains the fold develops into a fault. Near the 

axis of the anticline the beds in the southern limb dip gently, the 

slope becoming steeper and steeper, however, toward the south 

until, in the region of the shaly beds, dips of 60° are not uncommon. 

The northern limb is obscured by erosion, but the rocks composing 

it appear to dip at angles as great as 40°. Toward the south end of 

the anticline minor flexures are developed on its flanks and these in 

turn are squeezed up into what appears to be one or more closely 

folded overturns in the hills 1$. miles east of Eastlake Park. Other 

folds of considerable extent and at least one prominent fault trending 

approximately in the same general direction as the Elysian Park anti-
156 . OIL DISTRICTS OP SOUTHERN CALIFORNIA.

cline are exhibited in the Puente shale and sandstone to the northeast of the major flexure. Many of these latter folds are very sharp, 

dips of 60° or more being the rule. They are doubtless the result of 

tangential compressive stresses. South of Eastlake Park are violently disturbed beds whose structure is rather uncertain. Apparently, however, they lie in a closely compressed anticline, with axis 

trending in a general east-west direction along a line making a compound curve. This fold affects beds of probable Fernando age. The^ 

apparent analogy of this anticline, if such it be, to those in certain oilproducing areas of southern California leads to the inference that oil 

may be confined beneath it. However, those wells which have been 

put down east of Los Angeles River have not proved successful.

Southwest of the Elysian Park anticline is a syncline accompanied 

by a zone of faults. This flexure extends from the region southeast 

of Prospect Park in a broad northeasterly convex curve to the 

vicinity of the Sisters' Hospital on Bellevue avenue and separates the 

steeply dipping shale on the northeast from the softer flatter beds of 

the rolling-hill country southwest of the line of disturbance. (See 

PI. XX, sec.-E-F.) The southern extension of this syncline is traceable as a fault from the corner of Sunset boulevard and Sutherland 

street to a point just south of Inn.es street and thence southeastward 

toward the Sisters' Hospital, and is doubtless responsible for the breaks 

in the productive oil belt which occur in .the vicinity of the hospital.

The most prominent structural feature belonging to the east-west 

Pleistocene system is the fault zone extending along the southern face 

of the Santa Monica Mountains from Los Angeles River at least as 

far as Hollywood and probably much farther west. (See PI. XX, 

sec. C-D.) This fault zone has been largely instrumental in the formation of the range. It allows the upper Puente shale to come into 

contact with the granite, from which it is ordinarily separated by at 

least 2,000 feet of conglomerate and sandstone. Associated with this 

profound displacement are minor parallel faults in a zone which is 

characterized by many fractures and much distortion of the strata.

STRUCTURE OF THE OIL BELT.

The Los Angeles oil field is developed in strata at the top of the 

Puente formation on. the southern limb of the great Elysian Park 

anticline. (See PI. XX, sec. E-F.) The trend of the productive 

belt, however, instead of conforming to the axis of the main fold 

follows the strike of the formations on the south side of a divergent 

subordinate fold and hence has assumed a direction closely approximating east and west. The axis of the subordinate fold is traceable 

from a point near the corner of Lake Shore avenue and Temple street 

south of Echo Lake, westward to a point north of Westlake Park
LOS ANGELES DISTRICT: STRUCTURE. 157

where its trend changes to N. 70° W. Thence it passes westward at 

least as far as a point 1 mile southeast of Colegrove, where it is probably deflected still farther north of west and merges with the great 

anticline which tilts the Puente sandstone in a northeasterly direction on the west side of Cahuenga Pass. (See PI. XX, sec. C-D.) 

Between Lake Shore and Bellevue avenues the fold either blends 

with the Elysian Park anticline or is replaced by some undiscovered 

fault or other form of disturbance. The latter theory is strengthened 

by the evidence obtainable both east and west of the Sisters' Hospital 

where directly in line with an eastward extension of the fold there is a 

sharp line of disturbance (probably a complicated thrust fault) which 

extends to the east end of the field at the Catholic cemetery. (See 

PL XX, sec. G-H.) Another line of fracture, consisting of several 

more or less disconnected minor reverse faults, lies south of the subordinate flexure just described and toward the west diverges slightly 

from it. (See PI. XX, sec. E-F, and fig. 13, p. 171.) This fault 

zone appears in general to mark the northern, boundary of the productive belt. As a rule the beds lie nearly horizontal along the axis 

of the flexure, but dip more and more steeply toward the south as 

they approach the productive zone.. The oil appears to have accumulated in the sands of the southern limb of the anticline just below the 

point where the steeply dipping beds bend toward the horizontal 

before passing over the axis of the fold. The structure in the Salt 

Lake field, in the southern part of the Rancho la Brea, appears to be 

that of a minor flexure developed on the flanks of the fold along the 

southern limb of which the other Los 'Angeles fields are located. 

(See fig. 17, p. 189.) Apparently the axis of this minor flexure trends 

northeast and southwest. The brea along the south side of the 

Salt Lake field is formed by oil from underlying beds which probably 

has been forced upward by gas pressure along lines of fracture accompanying this flexure.

JOINT CRACKS.

All the rocks in the Los Angeles district are intersected by numerous 

joint cracks, along which, in many instances, slight displacements 

have taken place. These tiny fissures have doubtless played a most 

important part in the accumulation of the oil, for it is probable that 

whatever was its original source the transverse joint cracks in the 

shale and sandstone are largely responsible for its transference to the 

upper porous beds of the formation. Without these cracks the numerous impervious beds in the series would have precluded the passing of 

any fluid, least of all low-gravity oil, upward through the strata.
158 OIL DISTBICTS OF SOUTHERN CALIFORNIA.

OIL FIELDS.

LOCATION.

The oil-bearing zone begins near the Catholic cemetery on Buena 

Vista street, at the southern base of the Elysian Park hills, and trends 

in an almost westerly direction to a point north of West Lake; here 

it bends to N. 60° W. and extends into the region south of Colegrove. 

Two miles southwest of Colegrove, on the almost level Los AngelesSanta Monica plain, is the field locally known as the Salt Lake (so 

named from the principal company operating there), which, though 

topographically isolated from the main Los Angeles field, is, nevertheless, probably genetically related to it. In discussing this'subject 

it has been deemed advisable to divide the productive territory into 

. four parts, differentiated more or less sharply along structural lines. 

The area extending eastward from the Sisters' Hospital to the eastern 

limit of the productive territory at the Catholic cemetery will be 

described as the eastern field; that extending from the hospital to a 

line passing northward through West Lake as the central field; that 

extending northwestward from the region about the Baptist college 

as the western field; and that on the Rancho la Brea, southwest of 

Colegrove, as the Salt Lake field. (See PL XIX.)

DEVELOPMENT.a

The development of the Los Angeles oil district has taken place 

spasmodically, four periods of activity marking its history. The 

first period, during which the central field was first opened, covers 

the time from late in 1892 to 1895; the second, in which the eastern 

field was developed, includes 1896 and 1897; the third, or period of 

exploitation in the western field and the west end of the central field, 

embraces 1899 and 1900; and the fourth, which marks the development of the most important part of the district, the Salt Lake field, 

extends from 1901 up to the present time.

The history of the Los Angeles oil wells, or, more properly speaking, of the Second 

Street Park oil field at Los Angeles, is as follows: For many years a small deposit of 

brea was known to exist on Colton street near Douglas street, in the city of Los Angeles, 

and the brea was locally used for fuel. In 1892 Messrs. Doheny & Connon sunk a 4 by 

6 foot shaft, 155 feet deep, at the corner of Patton and State streets, close to the deposit 

of brea previously mentioned. The formation penetrated-is sandy shale, with a few 

thin strata of siliceous or calcareous rock. Near the surface the oil was very heavy, 

but at about 7 feet deep it was found to be lighter and it seeped from the sides of the 

shaft. The oil exuded from porous material and from the surface planes of the hard 

strata. The formation was found to dip toward the south at an angle of about 40°. 

Excavation below a depth of 155 feet was prevented by gas. An .18-inch hole was 

then drilled in the bottom of the shaft and yielded 7 barrels of oil daily for several 

weeks. In July, 1894, the yield had decreased to 2 barrels of oil a day. In November,

n The writer is largely indebted to the reports of W. L. Watts for data of a historical character used 

in this paper.
LOS ANGELES DISTRICT: DEVELOPMENT. 159

1892, an oil well was sunk at Second Street Park by Messrs. Doheny & Connon. As 

soon as this well was found to be a success other wells were sunk on adjacent lots, and 

the Second Street Park oil field grew rapidly. By the end of 1895 there were more 

than 300 wells within an area of less than 4,000,000 square feet. During 1895 the price 

of crude oil at Los Angeles fell to a ruinously low rate, the average price for that year 

being 60 cents a barrel. Indeed, there were sales at a much lower rate it is said even 

as low as 25 cents a barrel. The reason for this depression was the lack of cooperation 

among the oil producers and the lack of facilities for storing and handling the oil. 

Early in 1896 the price of oil commenced to recover, and in July, 1896, it had reached 

$.1. a barrel. The reason of this recovery was the diminishing of the supply, the organization of the oil producers, and the increased facilities for storing and handling the oil .a

Development in the central field proceeded eastward until it 

encountered the disturbed and barren beds in the region just west of 

the Sisters' Hospital, where exploitation ceased-. On the theory that 

this break was only local and that the productive zone continued 

eastward along the strike of the oil-bearing strata, a well was sunk by 

Maier & Zobelein at the corner of Adobe and College streets, in what 

is now the eastern field. This well was completed in November, 1896, 

and as soon as it was found to be successful many other wells were 

begun in the immediate vicinity, and by the middle of 1897 the wells 

in the new field were alinost as closely crowded as those in the old or 

central territory. Prospecting was continued east of Los Angeles 

River, but no economically productive wells were developed.

The exploitation of the western field and the extension of the central field from the corner of Quebec street and Ocean View avenue 

westward took place largely during the latter part of 1899 and 1900. 

Some wells, notably the Ruhland, at the corner of Seventh and 

Hoover streets, and several of the Maltman wells, north of the Baptist 

college, however, were sunk previous to 1897.

TJie entrance of the Salt Lake Oil Company into the Rancho la 

Brea region in 1901 marks the beginning of the development of the 

field now bearing that company's name. For je&rs the oil seepages 

and brea on this ranch had been known, and large quantities of brea 

had been hauled away for paving purposes. At least one prospect 

well had been put down near the brea deposit, but no important 

results were obtained from any of these operations. The first well 

drilled by the Salt Lake Company was abandoned on account of the 

caving in of the casing, caused by gas pressure. This fact being construed as a good indication, several other wells were sunk in the same 

locality until finally a "gusher" was struck and the value of the field 

assured. Since the beginning of 1902 the development in this territory has been rapid, and now it stands first in importance among the 

oil fields south of Santa Barbara County.

Owing to the proximity of the wells to each other the oil-bearing 

strata in the central and eastern fields have been rapidly exhausted,

a Bull. California State Mining Bureau No. 11, 1897, p. 5.
160 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

and many of the once-productive wells are now abandoned. During 

the past year (1905) the council of the city of Los Angeles took cognizance of this fact, and in order to do away with the nuisance of 

abandoned wells and pumping plants in a thickly populated residence 

quarter outlined certain districts within which all traces of the oil 

industry are to be removed within a certain period. This policy, if 

carried out, will eventually result in the abandonment of the city 

fields, so that probably in only a few years the thickly set derricks 

which now extend through the northern part of the city will be a 

thing of the past.

EASTERN FIELD. 

LOCATION.

The eastern field comprises that portion of the productive oil territory of Los Angeles which lies between the Sisters' Hospital grounds, 

corner of Sunset boulevard and Beaudry avenue, on the west, and the 

Catholic cemetery, corner of Cottage Home and Buena Vista streets, 

on the east. Its northern boundary is a line running from the northern part of the hospital grounds eastward to0 a point on the western 

line of the cemetery 600 feet north of Buena Vista street; its southern 

limits are Alpine street from the hospital southeastward to Figueroa 

street, and thence a line slightly north of east to the southwest corner 

of the cemetery. This area is nearly three-fourths of a mile long, 

with a maximum width of about 1,000 feet near the middle and a 

minimum of less than 400 feet at the ends; it contains approximately 

one-eighth of a square mile.

TOPOGRAPHY.

The eastern field lies on the southwestern flank of the Elysian Park 

hills, along the southern faces of the two well-developed minor ridges 

which are separated by Chavez Ravine. . The topography, however, 

appears to have no connection whatever with the structure of the 

field or the extent of the productive zone, the line of wells forming an 

approximately straight belt from the low southwestern slope of the 

western ridge at the Sisters' Hospital, up over the face of this same 

ridge, down into and across the mouth of Chavez Ravine, and eastward over the lower portion of the eastern ridge.

GEOLOGY.

All the formations from the Puente sandstone to the Fernando 

beds are involved in the geology of the eastern field. North of the 

field and forming the bulk of the Elysian Park hills is the thickbedded gray to light-yellow and rusty-brown sandstone of the Puente 

formation. This outcrops along some of the park roads and is exceptionally well exhibited on Buena Vista street east of the field and
LOS ANGELES DISTEIOT: EASTEBN FIELD. 161

west of Los Angeles River, where the peculiar jointing features, previously described, are prominently developed. Above the sandstone is the typical white siliceous shale, which extends in a broad 

band from the region of the Catholic cemetery northwestward along 

the flank of the Elysian Park hills. At the northwest corner of the 

cemetery this shale is very much crumpled, but northwest of this 

point it appears to be little distorted and dips about 45° S. 30° W. 

The top of the shale is marked by a 50-foot band of heavy-bedded, 

coarse light-yellow to brown concretionary sandstone, which is well 

exposed on the southwest side of Sunset boulevard near its intersection with Sutherland street. At the west end of this exposure the 

sandstone is cut off by a fault which has thrown some shale beds 

down against the sandstone on the west. The sandstone, together 

with its underlying and overlying white-shale bands, may be traced 

in a southeasterly direction from the locality last mentioned toward 

the oil field as far as the quarries on the west side of the Chavez 

Ravine road. Its dip along this line is also 45° S. 30° W. What is 

probably a continuation of the same sandstone band is exposed on 

the east side of the ravine a short distance north of the corner of 

Adobe and Bernardo streets, but the rocks here are so near the fracture zone and so much disturbed that the correlation is more or less 

uncertain. This sandstone layer- and its associated shale are easily 

differentiated in old surface exposures, but in fresh road cuts and 

quarries their identification is more difficult. The overlying band 

of shale, which is characteristically thinly laminated and of-flinty 

siliceous composition, underlies a considerable thickness of mediumto thin-bedded soft sandstone and sandy shale. These beds are well 

exposed in the brick company's quarries on the southwest side of 

Chavez Ravine. At the sharp bend in Figueroa street on the south 

end of the ridge west of the ravine, and extending westward at least 

as far as Ramona street just north of its intersection with College 

street, is another band of thin-bedded white shale which normally 

lies above, but which here is probably faulted down against the soft 

sandstone and sandy shale last described. This white shale is similar to that lying above the oil sands in the region west of the Sisters' 

Hospital and, like it, is much more resistant to weathering than th^ 

oil sands. If the .two shales are identical it would be reasonable to 

suppose that the oil sands lie only a short distance beneath the shale 

at the Figueroa and Ramona street outcrops. This supposition is 

borne out by the wells only a short distance south of the white-shale 

outcrop, which strike productive sands at depths somewhat greater 

than 600 feet. Owing to the faulting down of the oil-bearing beds 

against the older strata on the north, no outcrops of the oil sands 

have so far been discovered in the eastern field. The beds overlying
162 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

the oil zone are similar to those found in the same position in the 

central and western fields and consist largely of soft,, thin-bedded 

sandstone and sandy shale, dipping approximately S. 10° W.

GEOLOGY OF THE WELLS.

The underground geology of the eastern field is similar to that of 

the central, and is what would be expected from an examination 

of the surface evidence in the region. Within the productive territory 

the wells first penetrate the sandy shale of the Fernando, after which 

they enter the Puente clayey shale and "shell" beds which mark the 

top of the productive zone. Oil occurs in two sands, the upper being 

about 55 feet and the lower about 25 feet thick. At the present time 

the upper sand is practically exhausted, having been pumped continuously for nearly seven years. Ten or twelve barrels per day was 

not an unusual yield when the sand was first struck, and even three 

years ago some of the wells were, still yielding 1 or 2 barrels. The 

gravity of the oil in the upper sand is said to be between 18° and 19° 

B. The lower sand is medium to coarse grained and at first yielded 

as high as 25 barrels in some of the wells, but, like the upper sand, 

soon fell off and is now practically exhausted. The gravity of the 

oil in this stratum is about 16° B. Considerable quantities of gas 

accompanied the oil in the lower sand. Water occurs at a depth of 

about 900 feet in the neighborhood0 of Yale and Bernardo streets and 

in the extreme west end of the field was so abundant as to stop development work in the region south of the Sisters' Hospital.

The two following logs illustrate the strata penetrated in the areas 

of low and steep dip, respectively, in the productive territory of the 

eastern field:

Typical well log in the central portion (strata of loiv dip) of the eastern field, Los Angeles.a

Sandy shale. .............. . c. ...........................................................

Oil sand (oil 18.75° B.)........., ........................................................

,Oil sand (oil 16° B.) .................:..................................................

Thickness.

Feet. 

325

55

3

19

W

3

30

2

25

2

40

Depth.

Feet.

V)^

380

383

3Q1

450

453

483

485

510

512

552

oHershey, O. H.. Bull. California State Mining Bureau, No. 19, 1900. p. 45. 

Typical well log in the eastern portion (strata of steep dip) of the eastern field, Los Angeles.

- Thickness.

Feet. 

700

200

160

100

44

Depth.

Feet. 

700 don

1,060

1,160

1,204
U.S. GEOLOGICAL SURVEY 

CHARLES D.WALCOTT, DIRECTOR BULLETIN NO.3O9 PL.XX

Section A-B

 Sea. level

S tate Normal 

School

 el

Section C- D

Sect ion E~ F

ami Quaternary Fernando sandstone arid shale Pueitte shale Oil sands

Scale

' '2 i mile

Sect ion G~H

TCdgemonl

Pueivte Granitic i-ocks

Secul&veL

GEOLOGIC STRUCTURE SECTIONS TIIKOUGH LOS ANGELES OIL FIWJ)S, CALIFORNIA
LOS ANGELES DISTRICT: EASTERN FIELD. 163 

STRUCTURE.

PI. XX, sec. G-H, illustrates the probable relations .of the beds in 

the eastern part of the eastern field. The contour lines" in PI. XIX, 

showing the distance of the upper oil sand below the Los Angeles 

city datum (255 feet above sea level), also help to make clear the 

structural features of this district. As would be expected in a region 

where two important flexures come together at an acute angle, the 

structure is complex. The flexures referred to are the Elysian Park 

anticline, which trends N. 60° W. ; and the anticline and fault along 

the north side of the oil field, which trend in an approximately eastwest direction. As the beds of sandstone and shale in the Elysian 

Park anticline approach the east-west line of disturbance, they tend 

to deviate so that their strike is more nearly east and west. Similarly,, the beds following the line of the east-west disturbance are 

inclined to turn so that their trend is somewhat north of west as they 

approach the thick beds of the Etysian Park anticline. This tendency to change in strike occurs not only in the beds at the surface, 

but also in the oil sands, as is shown by the contours in PL XIX.

The structure in the major part of the eastern field is irregular, the 

average dip, however, being less than that of the central field. The 

inclination of the strata appears to be most regular just east of the 

Sisters' Hospital. From this point almost to Bernardo and Yale 

streets the dip becomes less and less, but near the latter point it 

increases abruptly to 50° or more. Toward the east the beds are 

very much disturbed. Near the corner of Ramona avenue and College street the dip is about 35°. Immediately south of this point is 

a line of fracture, on- the south side of which the strata dip 45°. 

The conditions beyond the east end of the field are not known 

because of the lack of surface outcrops and well logs.

The line of disturbance which begins west of Sunset boulevard, 

northwest of the Sisters' Hospital, and extends almost in a straight 

line to the corner of Bernardo and Adobe streets, appears to be a 

very sharp anticline bounded on the north by a fault in which the 

downthrow is on the south side. In a small cut on the west side of 

Sunset boulevard, in. the axis of this zone of disturbance, the beds 

dip from 80° N. to 80° S. This has the appearance of an overturn. 

However, dips obtained in the subway between the Sisters' Hospital 

and the boiler house and immediately north of the latter show an 

anticline with dips ranging from. 45° S. through horizontal to 45° N. 

A similar northerly dip is found northeast of the hospital on the 

corner of Beaudry avenue and the alley between Beaudry and Hinton avenues. These dips occur in thinly laminated yellqw sandstone

a The lines showing the position of the oil sand in the central and eastern fields are copied fromW.L. 

Watts's map of this field,'given in Bull. California State Mining Bureau, No. 19,1900, fig. D.
164 OIL DTSTEICTS OF SOUTHERN CALIFORNIA.

interbedded with minor amounts of arenaceous shale. The anticline, 

if such it be, is also exposed at the corner of Bernardo and Adobe 

streets, where the dip ranges from 75° N. through perpendicular to 

40° or 50° S. -Here, again, the surf ace evidence indicates an overturn 

while the well logs suggest a sharp anticline. The productive wells 

are found, with few exceptions, on the south side of this line of disturbance.

As before mentioned, there also appears to be a fault a short distance south of this anticlinal axis, but what relation, if any, it bears 

to the productiveness of the oil sands is at present unknown. The 

fault which throws the oil-bearing beds in the field down against the 

older Puente strata of the Elysian Park anticline is apparently closed 

so far as escape of the oil is concerned, for no indications of oil or 

asphaltum have yet been discovered along its trace. The sealing of 

the north end of the truncated oil sands b}^ the impervious material 

of this fault zone may account in a measure for the retention of the oil.

In the vicinity of Chavez Ravine, and immediately north of the main 

east-west fault, which limits the productive territory of the eastern 

field on the north, the strata strike N. 80° W., with dips varying 

from 20° to 30°. A disturbance affects the beds, however, at the 

corner of Elysian Park avenue and Innes street, just north of Reservoir Hill, where they dip in a northwesterly direction, although the 

dips all around this point are uniformly toward the south or southwest.

The territory between the eastern and central fields is considerably 

broken up and, as reported by the drillers, contains much water and 

little oil. This condition is doubtless due to a zone of disturbance 

which branches off from or is a continuation of the fault at the corner 

of Sunset boulevard and Sutherland street, and which extends from 

this point in a general south-southeasterly direction past the corner of 

Sunset boulevard and Innes street toward the Sisters' Hospital. The 

character of this line of disturbance has not been determined, but it 

appears quite probable that it is a fault zone, with the downthrow on 

the east.

DEVELOPMENT.

The first well drilled in the eastern field was sunk at the corner of 

Adobe and College streets in November, 1896. From the time this 

well was found to be successful until the latter part of 1897 development went on rapidly until nearly the whole of the productive territory 

was exploited. Since 1897 few wells have been put down, while a 

number of those which at one time produced considerable quantities 

of oil have become exhausted and have been abandoned. There are 

at present (February, 1906) 270 wells in the field, ^ which 211 are 

pumping and 59 are either not pumping or are abandoned. The wells 

vary in depth from 500 to more than 1,200 feet and yield from 1 to 

12 barrels of oil per day. Some of the wells are said to have yielded
LOS ANGELES DISTEICT : CENTRAL FIELD. 165

as high as 50 or 60 barrels at their inception, but these were unusual. 

In addition to oil the wells produce more or less gas. The oil is black 

and varies in gravity from 16° to 19° B., the lighter oil coming, it is 

said, from the higher sand.

CENTRAL FIELD. 

LOCATION.

The central field occupies the territory lying between the Sisters' 

Hospital, corner of Sunset boulevard and Beaudry avenue, on the 

east, and Coronado street, one-fourth mile north of Westlake Park, 

on the west. Its northern boundary is an almost straight east-west 

line drawn from the middle of the west side of the hospital grounds 

to a point on Coronado street about 100 yards north of Ocean View 

avenue; its southern boundary is Ocean View avenue from Coronado 

street east to Arnold street, thence a line east to the corner of First 

and Lucas streets, thence a line to the corner of Temple street and 

Beaudry avenue, and finally Beaudry avenue from Temple street to 

Sunset boulevard. The productive territory is about 1£ miles long, 

1,000 feet wide near its east end, and 300 feet near its west end. The 

total area is approximately nine-twentieths of a square mile. Like 

the eastern field, the central is a narrow band through one of the 

thickly populated residence districts of the city, the wells in many 

cases being put down in close proximity to houses and store buildings.

TOPOGRAPHY.

Northwest of the business portion of Los Angeles and east and 

northeast of Westlake Park is a tableland or terrace lying at an elevation of about 100 to 150 feet higher than the, main portion of the 

city. This table-land is bounded on the north and west by a ravine 

extending southwestward from a point immediately west of the north 

end of Echo Lake and is bisected by a narrow valley which contains 

Echo Lake and extends south-southwestward toward the business 

center. In addition to these, several small ravines drain toward the 

southwest from the top of the terrace. The central field occupies the 

top of the terrace immediately south of the ravine first mentioned, 

extends eastward across the table-land to the Echo Lake valley, down 

into and across this depression and up again on to the terrace, and 

thence across it to the eastern limit of the field at the Sisters' Hospital.

GEOLOGY.

The formations involved in the geology of the region immediately 

adjacent to the central field comprise the upper portion of the Puente 

formation, with its two bands of white siliceous shale and the intervening sandstone layer, and the soft sandstone and sandy shale of

Bull. 309 07 12
166 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

the Fernando. There is also a more or less persistent layer of Pleistocene gravel, which caps the upturned edges of the older beds over 

portions of the terrace.

The sandstone between the two white-shale layers, which is the 

principal oil sand in this as well as in the eastern field, consists of 

about 150 feet of coarse yellow arkose sandstone in layers 3 to 24 

inches thick, interbedded with minor quantities of fine gray shale. 

Good exposures of this sandstone are found on Court street immediately west of Lake Shore avenue and also on Burlington avenue^a 

short distance north of First street. Inx the region directly north of 

Westlake Park the color of this same band, which here approaches a 

grit in certain layers, varies from chocolate and purplish gray to 

brown. The discoloration is doubtless due to the petroleum which 

the sands at one time contained. Similar colors were noted in sands 

which are .supposed to be stratigraphically equivalent on Sunset 

boulevard northwest of Echo Lake. (See PL XXI, A.)

Interbedded with the thin white shale which underlies the sandstone are darker, softer shale and fine sandstone which locally appear 

to be petroliferous. A cut in First street west of Burtz-street offers 

a good exposure of this oil-bearing shale. These beds occupy the 

hilly country north of the central field, lying in low folds with dips 

that vary from horizontal to 10° or 15° and showing no continuous 

lines of structure. As indicated by well records, they carry traces of 

petroleum as far east and north as the region immediately northwest 

of Echo Lake, but the accumulations are not of economic importance, 

as they are in the same beds northwest of Coronado street in the 

western field. :

The band of white shale above the main oil sand already described 

is not over 50 feet thick, but owing to the resistant qualities of the 

thin flinty laminae of which it is composed it can be more easily 

traced along its surface outcrop than any other stratum in the 

region. Angular fragments of thin shale strew the surface of the 

ground throughout the greater part of the distance from Lake Shore 

avenue westward to a point 1^ miles southeast of Colegrove. If it 

were not for this hard, flinty shale the difficulty of tracing the continuity of the formations north of the central field would be greatly 

increased. v

Above this flinty shale band lie the soft conglomerate, heavy and 

thin-bedded fine-grained sandstone, and sandy and clayey shale of 

the Fernando. This formation is probably over 2,000 feet thick, only 

the lower part, however, being exposed in the central field. In this 

field the soft, thin-bedded sandstone is confined largely to the lower 

500 feet of the formation. This sandstone appears to be more or less 

petroliferous toward the west end of the field, and as a consequence 

its outcrop is stained rusty red, purple, and pink. This coloration of
U. S. GEOLOGICAL SURVEY

A. NODULAR MIOCENE SANDSTONE AT LOS ANGELES.

11. TYPICAL LOWER MIOCENE SANDSTONE AT LOS ANGELES
LOS ANGELES DISTRICT: CENTRAL FIELD. 167

the beds is. particularly noticeable along Ocean View avenue west of 

Alvarado street. Toward the east end of the field the sandstone is 

usually.light to dark yellowish brown. Above the soft sandstone and 

sandy shale is a zone of fine-grained shale, several hundred feet in 

thickness. Some of this shale is hard and appears to be more or less 

calcareous. Veins of gypsum are abundant in this part of the formation. Excellent exposures of this fine-grained shale are found on 

Beaudry avenue near Fourth street and in many road cuts both 

northeast and west of this locality.

The uppermost beds of the-Fernando exposed in Los Angeles lie 

south of the central field, occupying the ridge on which the State Normal School is located. These are soft clayey shales and heavy-bedded, 

fine, light-colored sandstone with some interstratified conglomerates. 

The fossils listed on page 153 came from these beds in the region south 

of the central field.

 GEOLOGY OF THE WELLS.

As indicated by the well logs, the underground geology varies somewhat throughout the extent of the central field. The southerly dip 

of all the beds, however, is common from one extremity of the field to 

the other. The strata in general are less disturbed and dip at lower 

angles in the east end of the field, and the oil sand on that account 

appears thinner in that region.^ In the territory east of Belmont avenue most of the wells penetrate sandy and clayey shale (Fernando) 

for the first 500 or 600 feet. Beneath this is the oil sand, consisting 

of 125 feet of thick layers of coarse arkose material interbedded with 

thin clayey shale. About 200 feet beneath this sand is the lower productive zone, which consists of 40 to 50 feet of medium to coarse sand 

in layers similar to those of the upper zone. The two oil-bearing beds 

are separated in the northern part of the field by about 200 feet of 

tough blue clay, but toward the south this thins out and the productive sands tend to coalesce. On the south edge of the field the 

rocks below a depth of 950 feet consist of alternating clayey and coarse 

sandy layers, which replace the heavy, well-defined 10 to 15 foot sands 

farther north. The gas pressure is stronger and the oil more abundant, heavier, and redder along the south edge of the field than in the 

same beds nearer the surface in the northern portion. This reddish 

oil, it is said, gradually turns black on exposure to the air. Below 

the lower productive zone is 15 to 20 feet of clayey shale and thinbedded sandstone carrying considerable quantities of water. The 

south edge of the field is defined by the line where this water becomes 

so abundant that it completely hinders development. The water level 

is said to be between 900 and 950 feet below the surface east of Belmont avenue and 1,050 feet west of it.
168 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

The following is a characteristic well log from, the northern part of 

the central field:

Log of well iwo llocks east of Lake Shore avenue, Los Angeles. 

[Elevation approximately 400 feet above sea level.]

Coarse oil sand .........................................................................

Thickness.

Feet. 

600

40

60

70

LSO

£0

104-

Depth.

Feet. 

600

640

700

 770

960

1,000

1,010+

The following log is characteristic of the region about Second Street 

Park, immediately east of Lake Shore avenue, the well being two 

blocks southwest of that whose log has just been given:

Log of well in Second Street Park, near Lake Shore avenue, Los Angeles, a 

[Elevation approximately 325 feet above sea level.]

Sand with water.

Thickness.

Feet.

125

200

3

Depth.

Feet. 

650

775

975

978

a Watts, W. L-, Bull. California State Mining Bureau, No. 11, 1897, p. 6.

West of Belmont avenue the dip becomes steeper, and although the 

water line becomes lower, and the wells consequently can go deeper, 

the field narrows appreciably. Between Burlington avenue and Alvarado street the productive territory is about 600 feet wide; west of 

Alvarado street it narrows to 500 feet, and at the end of the field, 

near Coronado street, to about 300 feet. Near the corner of Belmont 

avenue and First street the wells penetrate soft fine sandstone and 

sandy and clayey shale for the first 850 feet, below which they pass 

into a 50-foot zone of clayey shale, in which are interbedded petroliferous sandy beds called "stray" sands by.the drillers. The oil sand 

is struck at about 900 feet and is 100 feet thick, the dip here being 

between 30° and 40°. At 1,040 feet there is a 70-foot sand, which 

grades below into a white sand bearing salt water. This constitutes 

the lower limit of the productive zone.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XXII

¥..

A. EASTERN OIL FIELD, LOS ANGELES. 

Looking north from Baker Iron works.

B. CENTRAL OIL FIELD, LOS ANGELES. 

Looking east from near corner of First street and Belmont avenue
LOS ANGELES DISTRICT: CENTRAL FIELD. 169

A typical log for the part of the central field lying near Belmont 

avenue is as follows:

Log of well at comer of Bdmonl avenue and First street, Los Anye'les. 

[Elevation approximately 400 feet above sea level.]

Oil sand .......................................... ..................................

White sand with salt water. .........................................................

Thickness.

Feet.

50

100

40

70

10+

Depth.

Feet. 

850

900

1,000

1,040

1,110

1, 120+

In the region between Burlington avenue and Alvarado street the 

dip is steep, the oil sand being struck at about 700 feet on the north 

side of the productive belt, 900 feet in the middle, and 1,100 feet at 

the south edge. The strata above the oil sand consist largely of 

dark-colored shale and thin-bedded sandy layers, the latter occasionally petroliferous or water bearing toward the base of the section. 

Owing to the steep dip in this part of the field, the wells remain in the 

oil sand for a much greater distance" than they do farther east. There 

are also indications of a tendency toward coalescence of the oil sands 

here, caused by a partial pinching out of the shale beds. One well 

near the north side was drilled for over 300 feet through productive 

sand, with only a few thin layers of shale. The water plane in this 

portion of the field appears to be almost level, being struck at a depth' 

of about 1,200 feet on the north side and 1,250 feet on the south side. 

The water is salt, and displaces the oil in the sandy beds below these 

depths.

From Alvarado street westward to the end of the field the beds dip 

at angles varying from 50° to 70°, and the width of the field is reduced, to a minimum of 300 feet. The strata are practically the same 

as those penetrated east of Alvarado street, the only difference being 

that the water plane is a little lower at a depth of about 1,300 feet 

and the wells are in consequence a little deeper. The wells here 

are said, to be the most productive in the field, some of them having 

yielded 60 barrels a day at the start and kept up a steady production 

of 20 barrels for at least a year. Owing to the steepness of dip and 

the close proximity of the wells to the structural disturbance at the 

bend in strike, which occurs only a short distance west of the west 

end of the field, considerable difficulty is experienced from caving. 

Toward the northern edge of the field the wells go to 1,200 feet and 

obtain good results, but much water is encountered in many of the 

beds above the 700-foot level. At the south edge of the field the 

productive zone, which extends from a depth of 1,000 or 1,100 feet 

to the water plane at 1,300 feet, consists of clayey shale interstratified with oil-bearing "stray" sands.
170 OIL DISTEICTS OF . SOUTHERN CALIFORNIA.

STRUCTURE.

The most important structural feature in the central field is a line 

of disturbance which extends from the region 100 feet or so north of 

the corner of Patton and Temple streets westward to a point on Benton street about 200 feet south of First. (See PI. XX, sec. E-F.) Near 

this last point it bends and passes to the northwest toward Colegroove. 

This structural feature is in alignment with the fault along the north 

side of the eastern field,, and is probably a continuation of it. In 

fact, the only stretch of territory over which it can not actually be 

traced is that lying between the corner of Sumner place and Bellevue avenue, northwest of the Sisters' Hospital,, and a point north of 

Temple street near Patton. Throughout this stretch and north 

and south of it for some distance the beds all dip to the south at angles 

varying from 8° to 35°, and no evidences of folding or important 

faulting were observed.

The anticlinal structure of the flexure is attested by the fact that 

the beds dip to the south on Court street near Lake Shore avenue 

and to the north two blocks farther north. The more or less irregular 

position of the beds in the axis'of this anticline near the corner of 

Temple street and Lake Shore avenue indicates that considerable 

faulting accompanied the folding. The exposures on Sumner place 

between Sunset boulevard and Bellevue avenue, in the region northwest of the corner of Patton and Temple streets, on Burlington avenue 

200 feet or so south of Temple, and. on Benton street about 200 feet 

south of First offer further evidence in favor of the fault theory.

The southern or productive limb of the anticline, although much 

the steeper, shows more regularity throughout the central field than 

the northern limb. It is considerably broken and irregular at its 

east and west ends, but these conditions are probably due to other 

lines of disturbance crossing its strike. The dips near the axis of 

the anticline are usually low, becoming, steeper toward the south. 

The oil appears to accumulate in the steeper beds just below the point 

where they bend to the lesser dips near the axis. This is well shown 

in fig. 13, a section along C-F, PI. XVIII, across the field near Lake 

Shore avenue. The dips in the southern limb of the anticline in 

the east end of the field vary from 10° to 45°, becoming abruptly 

steeper toward the east end and reaching a maximum of 70° near 

the corner of Bellevue avenue and Victor street, just west of the 

Sisters' Hospital. This marked change in the dip is doubtless in 

some way related to the line of disturbance described in discussing 

the structure of the eastern field (pp. 163-164) as extending southward from the corner of Sunset boulevard and Sutherland street 

toward the Sisters' Hospital. To the west of Belmont avenue the 

dips become steeper, some of them being 70° or more, and the breadth 

of the field decreases in a corresponding manner. The productive
LOS ANGELES DISTRICT :. CENTRAL FIELD. 171

area is locally interrupted in the region immediately west of Coronado 

street, by the fractures attending the change in the direction of the 

strike of the beds.

A line of minor faults, some normal, others reverse or thrust, is 

developed on the south flank of the major flexure. A normal fault 

occurs on Welcome street 150 feet south of Council, and an excellent 

example of the thrust faults is shown about 25 feet north of Colton 

street on the west side of Lake Shore avenue. This secondary line 

of disturbance seems to mark practically the northern limit of the 

productive territory over a considerable portion of the field, but it is 

problematical whether this is merely a coincidence of position the 

productiveness of the sands depending on their distance from the axis 

of the anticline or their depth below the surface, or both or whether 

the minor faults really seal the upper ends of the oil-bearing beds

FIG. 13. North-south section across the central field on the line OF, Pis. XVIII, XIX, along the 

western side of Lake Shore avenue, Los Angeles. p,

and thus limit the field. The fact that a few productive wells are 

found north of the line of faulting offers evidence refuting the absolute 

effectiveness of the barrier even though it is operative over a portion 

of the territory, unless the explanation is that these wells pass through 

the tilted fault plane and derive their oil from the productive beds 

below and to the south of it.

North of the main line of disturbance the beds for the most parshow local flexures with low dip; these apparently bear little relat 

tion to the major structural features or to each other. The general 

anticlinal structure of the major flexure described in the preceding 

paragraphs is evidenced, however, by the recurrence in two knolls, 

cut through by Sunset boulevard northwest of Echo Lake, of the 

coarse sandstone (oil sands) found south of the axis in immediate 

proximity to the northern boundary of the central field.
172 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

DEVELOPMENT.

The central is the oldest field in the Los Angeles district, its first 

productive well having been sunk in 1892. As soon as oil was assured 

other wells were drilled in the immediate vicinity, and the field grew 

rapidly. The development of that part of the field lying east of 

First street "was practically complete by the end of 1896, while most 

of the wells in the western part were sunk during the period from 

1897 to 1900. There are at present (February, 1906) 516 wells in 

the central field, of which 206, or about 40 per cent, are pumping, 

while 310, or about 60 per cent, are either abandoned or not pumping. 

In the region west of Bonnie Brae street the proportion of pumping 

wells is 60 per cent, but in the eastern part of the field it is only 31 

per cent. This is doubtless due to the greater age of the eastern 

wells. The wells vary in depth from 500 to 1,400 feet, averaging 

deeper in the western than in the eastern part. The eastern wells 

now produce from 2 to 8 barrels per day, and the western wells go 

considerably higher, some possibly to 12 or 15 barrels. The average 

for the field is said to be about 4 barrels. At their inception some of 

the wells in the western part of the field gave 60 barrels per day, 

but soon fell off to 20 barrels. The gravity of the oil in this field 

varies from 14° to 16° B.

WESTERN FIELD. 

LOCATION.

The western field includes all of the oil-producing territory lying 

to the west and northwest of Coronado street, north of Westlake 

Park, with the exception of the area described on pages 186-195 as 

the Salt Lake field. In its restricted sense the western field is a belt 

trending N. 70° W., about one-half mile wide at its southeast end 

and one-fourth-mile wide at its western terminus southeast of Colegrove. Within this area of about 1J square miles are four rather 

distinct groups of wells, the area covered by them being something 

less than one-half the total area of the oil-yielding belt.

TOPOGRAPHY.

The region of the western field, viewed topographically, is one of 

transition from the pronounced hilly country northwest of Elysian 

Park to the broad, gently southward-dipping Los Angeles-Santa 

"Monica plain. Its characteristic features are low rolling hills, separated by more or less strongly pronounced ravines, which run in a 

southerly or southwesterly direction.
LOS ANGELES DISTRICT: WESTERN FIELD. 173 

GEOLOGY.

Superficial Pleistocene deposits cover a large part of the western 

field, but from the examination of exposures along the ravines in its 

eastern part and from a study of the well logs it is known that the 

formations underlying it are the same as those exposed in the eastern 

and central fields. These are the lower Puente sandstones, the 

Puente shale and thin-bedded sandstone, the Fernando sandstone, 

and the Pleistocene gravel, sand, and clay.

The most prominent bed exposed is the coarse sandstone which 

lies between the bands of hard, white, thin-bedded shale at the top 

of the Puente -formation. Exposures of this sandstone may be 

traced from the hill one-half mile north of Westlake Park to the bend 

in the Hollywood and Cahuenga Valley Railroad at the corner of 

Western avenue and Temple road. The exposures one-half mile 

north of Westlake Park show a medium to coarse or rather gritty 

sandstone, with colors varying from light yellow and brown to chocolate, gray, and dark brown. The beds are considerabty disturbed, 

being near the point of change of strike from N. 80° W. to N. 65°-70° 

N. West of this locality, toward the Baptist College, the sandstone 

outcrops along the face of the hill east of Occidental boulevard. 

Still farther west, at the corner of Commonwealth avenue and Geneva 

street, the sandstone dips 20° S. 20° W. and is interbedded toward 

the top with some thin layers of hard siliceous shale. Immediately 

southwest of the Baptist College the same sandstone, highly impregnated with oil, in layers from 12 to 36 inches thick, has a dip of 

20° S. At this point the sandstone is coarse and chocolate colored, 

and is interbedded with 1- to 12-inch layers of chocolate-colored 

shale, which contains large quantities of carbonaceous matter and 

some sulphur.

Immediately north of the Baptist College are some exposures of 

white thin-bedded shale, interbedded with softer, darker-colored 

shale which dips toward the south, under the coarse sandstone. This 

shale continues toward the northwest and is exposed in a much crumpled condition on First street about one block east of Vermont avenue. 

It also occurs in a small ravine near the junction of Rosedale avenue 

and the Hollywood and Cahuenga Valley Railroad. The last good 

exposure is found on Western avenue, just north of Temple road. Interbedded in the shale about 300 feet stratigraphically below the main 

layer of coarse sandstone, is a band of somewhat similar sandstone 

which appears to be the principal productive bed in the western field. 

This lower sand is well shown in a cut on the Hollywood and Cahuenga 

Valley Railroad at Vermont avenue. The dip here is 10° .due west. 

The sandstone looks very much like that exposed on Sunset boulevard 

and has similar large ellipsoidal concretions. It does not a,ppear to
174 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

contain any prominent shale layers, although it is overlain and underlain by the thin white siliceous beds. As exposed in this railroad cut 

the sand is about 50 feet thick, but the records of wells in other parts 

of the field show that it varies considerably in thickness and also in 

the number and prominence of the included shale layers.

Above the upper coarse sandstone are some layers of thin-bedded 

white shale^ which may be traced westward from the region immediately north of Westlake Park toward the corner of Fifth and Hoover 

streets, and thence northwestward across Vermont avenue to Western 

avenue, which it crosses about one-fourth of a mile south of Temple 

road. This shale, according to the well records in the region southwest of the corner of Western avenue and Temple road, probably 

averages somewhat thicker in the western field than it does in the 

central.

The Fernando is represented in the western field by rather hard 

gray to chocolate-colored shale, exposed on a small creek southwest 

of the Baptist College. The beds dip 22° S. 25° W. Some soft, thinbedded sandstone and sandy shale also occur in the formation above 

the hard beds near the base. Although there are few outcrops to corroborate the assertion, it is exceedingly probable that the Fernando 

overlies the Puente over the whole extent of the Los Angeles-Santa 

Monica plain, south of Temple road and at least as far west as the 

west end of Rancho la Brea.

As previously stated, the Pleistocene deposits consist of gravel, 

sand, and clay and lie unconformably upon the older rocks from the 

foot of the Santa Monica Mountains southward across the Los Angeles-Santa Monica plain. An excellent exposure of the Pleistocene 

occurs in the ravine northwest of the Baptist College. This deposit 

consists of sand and gravel of granitic quartz, sandstone, and shale 

fragments, some of the cobbles attaining a diameter of over 6 inches. 

The whole is richly impregnated with heavy oil, which seeps from the 

underlying sandstone and shale and imparts a dark chocolate color to 

the mass. Pleistocene deposits, consisting of roughly bedded sand 

and gravel, lying in an approximately horizontal position, may also be 

seen in cuts along some of the roads west of Hoover street.

/

GEOLOGY OF THE WELLS.

For convenience of discussion, the western field will be divided into 

four areas corresponding to the four more or less distinct groups of 

wells which it comprises. The first area the largest and by far the 

most important embraces the territory in the vicinity .of the Baptist 

College, and is bounded by Coronado street on the southeast and by 

Rosedale avenue on the west; the second area includes the region 

about the bend in the Hollywood and Cahuenga Valley Railroad at 

the corner of Western avenue and Temple road; the third is located
LOS ANGELES DISTRICT : WESTERN FIELD. 175

two or three blocks northwest of the second; and the fourth covers a 

few acres at the east end of the Rancho la Brea about a mile south of 

Golegrove.

BAPTIST COLLEGE AREA.

A reference to the geologic map (PL XVIII) will show that within 

the Baptist College area are the outcrops of five distinct zones, which 

are, from the base up, the oil-bearing thin-bedded shale and sandstone 

of the Puente formation, southwest of these the 150-foot oil sand of 

the central field, the white-shale zone at the top of the Puente, the 

thin-bedded sandstone of the Fernando, and over all in more or Jess 

scattered patches the Pleistocene gravel and sand. Oil is derived 

principally from a zone (probably corresponding with the lower oil 

zone of the central field) of interbedded clayey shale, "shell," and oil 

sands, the top of which lies from 200 to 400 feet below the bottom of

FIG. 14. North-south section on the line W-F, Pis. XVIII, XIX, along Hoover street from First 

to Sixth streets, Los Angeles, showing the structure of the western field.

the main oil sand of the Los Angeles district. As would be expected, 

the logs of the wells in this area farthest toward the southwest give the 

most complete records. The Fernando formation consists of sandy 

shale and fine sandstone, beneath which are the clayey shale and interbedded "shell" layers which lie above the thickest sandstone bed. 

This sandstone bed (first oil sand), where reached by wells south of its 

outcrop, usually gives a small yield of heavy oil. Below the sandstone the wells penetrate about 400 feet of thin-bedded blue clayey 

shale, thin hard "shell," and interbedded oil-bearing sands. Between 

130 and 170 feet above the bottom of this shale is a layer of coarse, 

water-bearing sand, and at its base is.a 20 to 50 foot oil sand, the 

greater thickness in wells in the southwestern part of the area, the less 

in the wells which start down north of First street. From this horizon 

down the well logs show considerable discrepancy. Blue clayey shale,
176 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

containing thin to moderately thick beds of oil sand with some waterbearing strata between appears to lie beneath the lower or second oil 

sand in most of the wells. Water with a temperature of 104° was 

struck in a well at the corner of First street and Vermont avenue at a 

depth of 800 feet. In this well from 800 down to 1,735 feet the strata 

are. blue clayey shale and some "shell." A heavy flow of water was 

encountered at 1,400 feet. The sandy shale from 1,400 to 1,735 feet 

yielded some oil and gas. The record of a well drilled immediately 

southwest of the corner of Fourth and Hoover streets reveals some 

interesting facts. The first oil sand in this well (probably the second 

of the above discussion) was encountered at 250 feet and extended to 

350 feet. This productive sand, as reported, was succeeded below by 

water-bearing sand, with no shale or other parting between. When 

the depth of 350 feet was reached the well yielded from 75 to 100 barrels of oil containing no water for a time, but finally water came from 

below and the well was temporarily abandoned. After it had lain idle 

for five or six months operations were again begun, but the moment 

the water in the well was agitated the strong gas pressure threw water 

and oil 30 or 40 feet into the air. Drilling was recommenced after this 

spasmodic "gush," but water-bearing sands and some shale were the 

only strata penetrated to 1,000 feet, where a 6-fopt layer of coarse 

bowlders was encountered. From l,000.feet down the formation was 

clayey shale, with a 20-foot oil sand between 1,100 and 1,200 feet and 

another 50-foot sand between 1,300 and 1,400 feet. These sands 

were very productive, but owing to the softness of the beds the water 

could not be shut off and was always troublesome.

In the territory southwest of the corner of Sixth and Hoover streets 

the wells start down in the beds overlying the first oil sand (here 

almost barren), penetrate the sand for about 150 feet, pass through 

300 to 400 feet of clayey and sandy shale and reach the second or 

productive sand, from 60 to 90 feet thick, at a depth of about 525 

feet. North-northeast of this locality, in the region about the corner 

of Hoover and Geneva streets, the second sand (the first encountered 

in these wells) is struck at about 190 feet and is 22 feet thick. About 

50 or 60 feet below this sand is another 60-foot productive zone. The 

same relative conditions as have just been described' exist along the 

strike of the beds toward the northwest, the shallow wells,. varying 

in depth from 140 to 400 feet, occurring- in the northeastern portion 

of the field, while the deeper wells are found along the southwestern 

border.

The oil in many of the wells in the Baptist College area has been 

succeeded by water, which appears to follow up the oil from below. 

There is also more or less water in all the producing wells, some, it is 

said, yielding 75 barrels of water for each 25 barrels of oil. Gas
LOS ANGELES DISTEICT: WESTEEN FIELD. 177

occurs in most of the wells, but not in sufficient quantities to be of 

economic importance. The oil is mostly black, but the emulsion of 

oil and water as it is pumped from the wells usually appears bronze 

colored. Some of the wells near the corner of Dome and Hoover 

streets, high up on the rise of the oil sands and not far from the axis 

of the anticline, yield red oil, which, however, becomes black on 

exposure to the air. The gravity of the oil in the Baptist College 

area varies from 12.5° to 14.5° B. The production is from a fraction 

of a barrel to 5 or 6 barrels per day. Some of the wells are said to 

have started with a production of 75 to 100 barrels but fell off to 30 

barrels after ten months, 3 barrels after two years, and 1$ barrels 

after three years. The effect of the new wells on the old was imperceptible, the decrease in production being due to a local sapping of 

the sand immediately surrounding the well.

The three following logs are characteristic for their respective 

localities:

Log of well immediately southwest of the corner of Hoover and Fourth streets, Los Angeles. 

. [Elevation approximately 275 feet above sea level.]

Coarse sand, with clayey and sandy shale and occasional thin " shell " layers toward

Thickness.

Feet. 

250

100

050

6

94

20

180

50

80

Depth.

Feet. 

250

350

1,000

1,006

1.100

1,120

1,300

1,350

1,430

t Loy of ivell immediately northeast of the corner of Hoover and Geneva streets, Los Angeles. 

[Elevation approximately 290 feet above sea level.]

Thickness.

Feet. 

00

130

22

3

55

58

Depth.

Feet. 

60

190

212

215

270

328
178 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

Log of well southeast of the corner of Vermont avenue and First street, Los Angeles. 

[Elevation 260 feet above sea level.]

Blue clayey shale and thin sandstone, some of latter oil bearing; water sands between

Alternating blue clayey shale and medium- to fine-grained, thin-bedded sandstone. . . .

Thickness.

Feet. 

80

400

20

300

2

28

5

15

3

547 1-1-

334

Depth.

Feet. 

80

480

500

800

802

830

835

850

853

1,400 

1,401 i ?'<<;

CD:e 238'

v'.v'.v Sand,adobe,clay 

Hardshell

mm Dead oil sand 

Live oil sand

300 LFIG. 15. Detail of section along the line C-D, Pis. XVIII, XIX, western oil field. Small letters refer 

to locations of wells on section C-D, PI. XX.

VICINITY OF WESTERN AVENUE AND TEMPLE ROAD.

The formations underlying the area east of the corner of Western 

avenue and Temple road are the same as those found toward the 

southeast, in the region of the Baptist College. The surface outcrops seem to indicate that the dip of the beds is toward the southwest, but from the evidence offered by a group of wells just south of 

Temple road one-fourth mile east of Western avenue, the dip appears 

to be south-southeastward about 4 feet in 300 feet. This discrep-
LOS ANGELES DISTRICT: WESTERN FIELD. 179

ancy is doubtless due to the proximity of the area to the axis of the 

Los Angeles antidine.

The wells in the northern part of the area, near Temple road, after 

penetrating gravel and sand for approximately 100 feet pass through 

alternating clayey shale and fine sandstone for about 250 feet. At 

this depth the oil sand, which appears to be barren at the top but 

productive below, is encountered and extends for 35 feet. About 

20 feet below this is a layer of sand which yields flowing water. The 

wells in this part of the area yield an average of 1 to 2 barrels of 

15° B. oil per day, and in addition considerable quantities of gas 

and usually less than 2 per cent of water.

About one-fourth mile to the southwest down the dip from the territory just described the wells reach the oil sand at 310 feet. The 

sand is here 40 feet thick and is somewhat more productive than it 

is higher up, yielding on an average 6 barrels per day per well. The 

same strata were penetrated and the same amount of water is encountered in these deeper wells as in the wells to the northeast.

Still farther southwest, about one-half mile southwest of the corner 

of Western avenue and Temple road, the wells strike an oil sand at 

a depth of about 350 feet which outcrops at the surface in the vicinity 

of the wells just described. This sand furnishes the main yield of 

these wells. About 350 feet below this upper oil sand is encountered a 

second oil zone corresponding to the productive sand of the wells half a' 

mile to the northeast. The strata above the first sand are largely clayey 

and sandy gray shale, possibly Fernando in part, with some harder 

shale and "shell' 7 layers immediately above them. Between the first 

and second oil zones are alternating clayey and sandy shale with a few 

thin layers of hard siliceous shale or "shell;" isolated accumulations 

of oil and gas occur throughout these beds.

The three following well logs are characteristic of the region near 

Western avenue:

Log of well one-fourth mile east of the corner of Temple road and Western avenue,

Los Angeles.

["Elevation, 280 feet above sea level.]

Thickness.

Feet. 

45

30

20

20

12

6

15

17

q

38

35

35

20

Dop.th.

Feet. 

45

 7K.

95

115

T33

1 AQ

165

J68

206

241

97ft
180 OIL DISTRICTS OP SOUTHERN CALIFORNIA.

Log of well one-fourth mile east-southeast of the corner of Temple road and Western avenue,

Los Angeles.

| Elevation, 245 feet above sea level.]

Soil.....................................................................................

"Adobe"...............................................................................

"Adobe".................................:.............................................

Oil sand ................................................................................

Thickness.

Feet. 

50

20

20

10

135

7K

40

40

70

10 ?n

40

10

5

7P

Depth.

Feet. .

CTi

70

QA

100

OQK

O1 A

350

390

460

470 finn

540

550

555

625

Log of well one-half mile southwest of the corner of Temple road and Western avenue,

Los Angeles.

[Elevation, 238 feet above sea level.]

Thickness.

Feet. 

40

8

4

22

23

9

1

27

1

2

30

79

1

38

41

61

2

fi

2

2

3

4

14

60

5

21

70

1

20

1

6

21

19

31

1

10

9

21

3

7

15

7

4

2

35

30

2

33

5

30

3

29

Depth.

Depth. 

40

49

19

74

97

106

107

1 1%

1 4Q

151

260

261

OQQ

340

401

403

409

411

413

416

420

AVA

494

499

COA

ion

591

611

612

618 fi'M

fi^a

689

690

700

709

730

7OO

740

755

762

766

768

803

833

835

868

873

903

906

935
LOS ANGELES DISTRICT: WESTERN FIELD. 181

AREA ONE-FOURTH MILE NORTHWEST OF TEMPLE ROAD AND WESTERN AVENUE.

The underground geology in the vicinity of the little group of wells 

in the SE. J .sec. 14, T. 1 S., R. 14 W., one-fourth mile northwest of 

the corner of Temple road 

and Western avenue, introduces a new structural 

factor in the shape of a 

northeast - southwest line 

of disturbance. In a j ourney westward through the 

western field this is the 

first evidence encountered 

of the secondary zone of 

disturbance which to the 

southwest develops into

the Salt Lake flexure. 

The line of disturbance or 

fault appears to extend in 

a southwesterly direction 

from the northeast corner 

of the SE. £ sec. 14, 

through a point 80 feet 

west of Loma Vista well 

No. 5, and thence indefinitely toward the Salt 

Lake field.

East of this line of disturbanco the main oil 

zone, which is here from 

80 to 90 feet thick, is encountered at a depth of 

between 195 and 210 feet, 

the overlying beds consisting of Pleistocene sand 

and gravel near the surf ace, with thin-bedded 

shale and fine sandstone 

below. The wells yield as 

high as 20 barrels per day 

when they first come in, 

but this production falls 

off and at the end of two 

years is in few cases over 

2 barrels. The original FlG> 16-~~r>etail cf section along the line A-B, PL xvui,

 i . -i i .. . , western oil field. Small letters indicate locations of wells on nign production is caused secti0n A-B, PI. xx,

 Bull. 309 07 13

ABi'b AB'-c AB:d

o A f\* oyi e* oo r\T

Shale

Sandy shale

Sand, adobe, clay

Hard shell

Deadoil sand and tar streaks
182 OIL DISTKICTS OF SOUTHERN CALIFORNIA.

by the gas pressure, which is rather strong in this area. West of the 

line of disturbance water is encountered in the wells at a depth of 

400 feet, but no oil was struck, although one of the wells was continued to 580 feet.

AREA SOUTH OF COLEGROVE.

The wells in and near the SE. f sec. 15, T. 1 S., R. 14 W., about a 

mile south of Colegrove, penetrate the same strata that underlie the 

Salt Lake field, a mile and a half to the southwest. The wells reach 

the oil zone near the surface, where it is unproductive and almost 

dry, while those of the Salt Lake field encounter it at depths of 1,000 

to 3,000 feet, where it is exceedingly rich in oil and gas. The 'two 

areas offer an excellent illustration of the differences in saturation 

of a single zone at different points, and also of the fact that within 

reasonable depths oil-bearing strata which outcrop at the surface or 

whose truncated ends are overlain near the surface by comparatively 

thin deposits of porous material are deprived of most of the petroliferous contents of their upper portions either by slow distillation 

or by some other process.

The wells of the Colegrove area penetrate Pleistocene sand, usually 

water bearing at the base for about 50 feet, below which they enter 

thin-bedded clayey shale, sandstone, and "shell/' The northeasternmost wells strike the oil sand at a depth of a little more than 100 

feet, and from this point down for.at least 300 feet pass through 

alternating layers of oil sand, clayey shale, and "shell/' with here 

and there one of conglomerate. From the northeastern edge of the 

Colegrove area the oil sands dip toward the southwest at an angle of 

about 22°, being encountered at greater, and greater depths in the 

wells as the Salt Lake field is approached. The wells farthest northeast start down in beds which underlie, what has been called the

"first" of "150-foot" oil sand, but those situated southwest of the

middle point of the line dividing the SW. £ from the SE. \ of sec. 15 

penetrate this sand at depths varying from 100 feet down. A well 

located about one-eighth of a mile west of the middle of the south line 

of sec. 15 strikes this first oil sand at 722 feet and from this depth 

down to 1,532 feet penetrates an almost scontinuous series of oil- and 

gas-bearing sandstone and sandy shale interbedded with clayey shale 

and thin layers of hard siliceous shale or "shell." For some reason 

the sands here are not very productive and no important wells have 

been developed over this part of the area.

Northeast of the Colegrove area the oil-bearing shale and sandstone pass over the Los Angeles anticline and extend in low folds 

toward Prospect Park. Traces of oil and gas have been found in these 

beds in nearly all the wells drilled between the productive belt and 

the Prospect Park region, but no accumulations of consequence have 

been encountered.
LOS ANGELES DISTRICT: WESTERN FIELD. 183

The three following well logs indicate the character of the strata 

in the Colegrove area. They are given in order down the dip of the 

strata from the northeast edge of the area toward the Salt Lake field.

Log of well on northeast edge of the group drilled in the SE. { sec. 15. T. 1 S., R. 14 W.,

Los Angeles.

[Elevation, 239 feet above sea level.]

Soil....................-..........-...................................!.................

G ray clay ..............................................................................

Fine black sand and clay; water at 47 feet, but soon exhausted .......................

Tar sand in 3-foot layers ....................................................... ..... .

Thickness.

Feet.

8

21

15

22

40

7

6

29

6

84

37

Depth.

Feet.

14

35

50

72

112

119

125

154

160

inn

280

317

322

Log of well on southivest edge of the group drilled in the SE. \ sec. 15, T. 1 S., R. 14 W.,

Los Angeles.

<»

[Elevation, 245 feet above sea level.]

Shale; 1-foot "shell" at 284 feet; 3-foot "shell" at 302 feet ...........................

Shale...................................................................................

Oil sand; 1-foot "shell" at 380 feet; 4-foot "shell" at 448 feet; 1-foot "shell" at 484

Thickness.

Feet. 

50

83

4

10

108

1

7

1

7

156

10

9

2

48

Depth.

Feet. 

50

133

337

147

255

256

. 363

364

371

527

537

546

548

596
184 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

Log of well one-eighth mile west of middle of south line of sec. 15, T. 1 S., R. IJ+W., Western Oil Field, Los Angeles.

[Elevation, 240 feet above sea level.]

"Shell"...........................................................................,....

Alternating tar sand and shale, showing of oil and gas between 1,249 and 1,254 feet ...

Hard ' ' shell" . .........................................................................

' ' Shell ' ' and gray sand, carrying tar and gas; sand looks like wa.ter sand , but no water 

in it ..................................................................................

White sand, hard at base ..............................................................

Tar bed, with pure tar. ................................................................

Whito Sand. ............................................................................

I

Thickness.

Feet. 

11 

29 

70 

2 

81 

11 

139 

349 

80 

6 

12 

60 

2 

6 

17 

15 

' 35 

35 

20 

20 

6 

5 

30 

59 

85 

5 

04 

36 

6 

7 

5 

10

18 

12 

2 

10 

4 

9 

13 

7 

3 

82 

15 

3 

12 

7 

5 

8 

4 

12

Depth.

Feet. 

11 

40 

110 

112 

193 

204 

343 

092 

772 

778 

790 

850 

852 

858 

875 

890 

925 

960 

980 

1,000 

1,006 

1,011 

1,041 

1,100 

1,185 

1, 190 

1,254 

1,290 

1,290 

1,303 

1,308 

1,318

1,336 

1,348 

1,350 

1,300 

1,364 

1,373 

1,386 

1,393 

1, 396 

1,478 

1,493 

1,496 

1,508 

. 1,515 

1,520 

1,528 

1,532 

1,544

STRUCTURE.

The structural conditions in the western field are graphically illustrated by PI. XX, which shows a section along the line C-D from 

1 mile southwest of the corner of Western avenue and Temple road 

to Edgemont (see also fig. 15), and another section along the line 

A-B, showing the underground geology from the Colegrove area to 

the Salt Lake field (see also fig. 16), and by fig. 14, a section along 

Hoover street. The principal structural feature in the field is the 

northwestward continuation of the Los Angeles anticline. The trend 

of this flexure changes from N. 80° W. to N. 65°-70° W., at the east 

end of this field, west of Coronado street. The area of the change 

of trend lies northeast and southwest from the corner of Sixth and
LOS ANGELES DISTBTCT : WESTERN FIELD. 185

Hoover streets, and is one of considerable fracturing and distortion, as 

is evidenced by the dips which occur in its vicinity. Northwest of the 

disturbed area the strata along the southwestern limb of the anticline 

are inclined at angles of 20°-25°, S. 20°-25° W. As the beds approach 

the axis they flatten out, passing gently over it into the low local 

folds and flexures which characterize the rolling country to the north, 

not only of the western, but of the central field also. (See fig. 14.)

The Los Angeles anticline is complicated by faulting in this field, 

as it is in the region to the east. This is well shown by an exposure 

on First street, one block east of Vermont avenue, where the beds are 

.much distorted and broken up. From this point the line of disturbance passes near the junction of Rosedale avenue and the old Hollywood and Cahuenga Valley Railroad; thence, as shown by well records, across Western avenue at a point somewhere less than a quarter 

of a mile north of Temple road, and thence into the group of wells 

which lie about a quarter of a mile northwest of the corner of Western 

avenue and Temple road. A new line of disturbance, probably a 

fault and doubtless related to the Salt Lake flexure (see p. 194), is 

encountered in this last-mentioned group of wells and extends in a 

northeast-southwest direction across the trend of the anticline. The 

geologic conditions are different on the two sides of the fault line, and 

from this it is safe to assume that the structural conditions are also 

different, but just what effect the fault has had on the main anticline 

is problematical. Evidence offered by the logs of the Colegrove 

group of wells and of other wells between this group and the Salt 

Lake field and by the great monocline in the region of Cahuenga Pass, 

in the Santa Monica Mountains to the north, appears to indicate a 

northwestward extension of the anticline past the transverse fault, 

toward the mouth of Laurel Canyon. A glance at the geologic map 

of the western field clearly demonstrates that most of its structural 

features are determinable only by a comparison of the well logs. It 

has therefore been necessary to depend almost entirely on these logs 

in working out the structure of the great southwestern limb of the 

Los Angeles anticline^ In the area southwest of the Baptist College, 

where the anticline recovers from the distortion and fracturing 

accompanying its change of strike farther east, this southwestern 

limb (or monocline, as it may be considered in this territory) dips at 

angles of 20°-22°, S. 20°-30° W. The dip near Western avenue and 

Temple road is a little more toward the south, and, being nearer the 

axis, is but about 12°, while half a mile to the southwest the dip is 

approximately 26°. One-half mile farther west the slope flattens out 

to 23°, and still farther northwest, in the area southwest of the Colegrove group of wells, it is only 22°, continuing s practically at this 

angle, at least so far as its southwestern element is concerned, to the 

Salt Lake field. Evidence secured in this field indicates that a local
186 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

flexure trending northeast and southwest probably changes the general dip of the beds from southwest in the region of the Colegrove 

group of wells to west and then to northwest toward the center of the 

Salt Lake-field.

The contour lines on the map (PI. XIX) give an approximation of 

the depth of the top of the upper oil sand or zone below Los Angeles 

city datum (255 feet above sea level).

SALT LAKE FIELD. 

LOCATION.

The Salt Lake field so named from its first important producing 

company occupies an area approximately a mile square near the 

intersection of Fourth street and La Brea road, 7 miles west of the 

business portion of Los Angeles. The productive territory as now 

developed embraces the northwestern part of the SE. J, the northeastern part of the SW. \, and the southern part of the N. £ sec. 21, 

T. 1 S., R. 14 W. In addition to this there are some important wells 

in the central part of the E. ^ sec. 20 and some small producers in the 

NW. J sec. 28.

The field occupies a part of the Los Angeles-Santa Monica plain, 

which extends southward with a gradually lessening slope from the 

base of the Santa Monica Mountains toward the hills southwest of 

Los Angeles. (See PI. XXIII.)

GEOLOGY.

GENERAL STATEMENT.

Alluvium and Pleistocene deposits of gravel, sand, and clay cover 

the plain in the region of the Salt Lake field, but surface outcrops of 

other beds are to be found no nearer than about 2 miles from the 

present developed territory. The well logs and a study of the adjacent territory indicate, however, that the formations involved in the 

geology of this field include at least a part of those exposed to the 

east in the vicinity of the Los Angeles city field. They are (a) 2,000 +. 

feet of Puente sandstone; (&) 2,000± feet of upper Puente shale and 

thin-bedded sandstone; (c) 2,000+ feet of Fernando clayey and 

sandy shale, sandstone, and gravel, and (d) an unconformable capping 

of Pleistocene gravel, sand, and clay varying in thickness from 40 to 

190 feet or more, the whole.covered by alluvium. A detailed description of these formations is given in the discussion of the general 

geology of the district and will not be repeated here.

OIL SANDS.

The most productive sands occur at the top of the Puente formation although traces and locally more or less important accumulations 

of oil and gas are found in the shale above the principal oil zone.
U. S. GEOLOGICAL SURVEY 

SALT LAKE FIELD, LOS ANGELES. 

Looking north from near lagoon.
LOS ANGELES DISTRICT : SALT LAKE FIELD. 187

The oil is supposed to be derived largely from the diatoms and other 

minute organic remains found in the underlying shale and finds its 

way into the sandy layers mainly through the multitude of joint 

cracks which penetrate both the shale and sandstone.

BREA DEPOSITS.

The brea deposits in the Salt Lake field are the most important in 

the Los Angeles district. They cover a considerable territory in sec. 

21. (See PI. XXIV, B.) A number of years ago large quantities of 

this brea were removed and used for paving purposes, the resultant 

depression filling up with water and forming a lagoon. The brea is 

largely, the result of the impregnation of porous sand and soil by oil 

oozing up from below. That the process is still going on is evidenced 

by the heavy oil which may be seen oozing from the banks of the

lagoon and of several other brea pits in the vicinity. Large quantities of gas are also escaping in the same region, as is shown by the 

intermittent streams of bubbles which rise to the surface of the water 

in the lagoon and other depressions thereabouts. (See PL XXIV, B.) 

The logs of several wells indicate that brea occurs in the basal Pleistocene beds over a considerable territory contiguous to the lagoon 

where it is invisible on the surface. The formation of brea over an 

area relatively so large implies the escape of vast quantities of oil 

from the underlying Tertiary beds. This escape of the oil and gas is 

probably made possible by the fractured condition of the rocks. On 

the evidence offered by the great brea deposits and the large quantities of escaping oil and gas in the region of the lagoon the theory is 

advanced that considerable fracturing has accompanied the formation of the Salt Lake flexure.

GEOLOGY OF THE WELLS.

For the convenience of discussion of the underground geology, the 

Salt Lake field will be divided into two parts by a hypothetical line 

running in a general northeast-southwest direction through the 

lagoon and coinciding in a general way with the axis of the supposed 

Salt Lake flexure.. The area to the northwest of this line contains 

most of the productive wells, and there are no important producing 

wells in the area southeast of the line.

AREA NORTH AND NORTHWEST OP THE LAGOON.

In the area north and northwest of the lagoon the wells for the first 

50 to 100 feet penetrate alluvium and Pleistocene clay, coarse sand, 

and gravel the mantle of the older formations. The Pleistocene 

beds usually carry two water-bearing layers, one at a depth of 20 to 

30 feet, the other (which appears to lie at the base of the formation) 

at 50 to 100 feet from the surface. In some of the wells the lower
188 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

layer is highly charged with sulphur and other minerals, which are 

probably derived from the underlying shale. These surface waters 

are usually shut off in the sandy or clayey shale at depths of about 

150 feet. Brea and heavy oil are also occasionally encountered at 

the base of the Pleistocene, having accumulated at the top of local 

fracture zones which penetrate the underlying oil-bearing strata. In 

fact in some parts of the field, especially in the vicinity of the supposed flexure, oil appears to impregnate the soil and rocks "from the 

grass roots down."

From the base of the Pleistocene to the first important oil sand, 

which is struck at 1,000 to 3,000 feet, the rocks penetrated are essentially clayey and sandy shale (the latter known locally as "adobe") 

interbedded toward the base with a few 1- to 5-foot layers of hard 

siliceous or calcareous shale (the " shell" of the drillers). The great 

bulk of this shale probably belongs to the Fernando formation. The 

sandy and clayey facies of the" shale appear to grade into each other 

both laterally and vertically, so that the personal equation of the 

driller enters largely into their differentiation. Gravel and coarsesand lenses are also encountered in some of the wells, but these are 

usually only local in extent and of little importance.

Gas and oil, increasing in quantity downward, are found in man}^ of 

the beds of the formation, the most important accumulations occurring as a rule just beneath the hard, impervious "shell" layers. 

Some of these gas accumulations or pockets are confined under great 

pressure and when penetrated by the drill have been known to clean 

out the well with considerable force. The shale beds near the flexure 

or anticline appear to be more petroliferous than the same layers 

farther away, to the northwest of the flexure. This is doubtless diie 

to the more or less fractured condition of the rocks in the vicinity of 

the disturbance, which allows the oil and gas to penetrate many of 

the beds of the shale which otherwise would be impervious. A persistent stratum of salt water occurs beneath a "shell" layer at about 

950 to 1,000 feet above the top of the first important oil sand in the 

area northwest of the flexure, but does not appear in any of the wells 

southeast of it. (See fig. 17.) Salt water is also encountered in some 

of the wells at horizons 150 to 200 feet and 650 feet above the oil zone.

The oil zone proper varies in thickness from 150 to 500 feet and 

consists of fine to coarse sand interstratified with clayey shale and 

" shell." The logs of a few wells near the flexure show no well-defined 

oil sand, but rather a series of thin productive sands interbedded with 

clayey and sandy shales. ' Whether,? the sand occurs as persistent 

layers or as lenses is problematical, although from the evidence in 

hand it appears highly probable that it is present in both forms 

within the area under discussion. It is known, however, that the 

uppermost important oil sand in the wells over a large part of the
U. S. GEOLOGICAL SURVEY

A. CHARACTERISTIC THIN-BEDDED PLIOCENE SANDSTONE, LOS ANGELES OIL FIELDS.

li. LAGOON IN SALT LAKE FIELD, LOS ANGELES. 

Showing floating oil and bubbling water due to escaping gas.
00

Ci 

si 

o-

'£ 

<o *l

O

£*-<

Q 

fr^

% o3 O

O °

Alluvium.clay, Sandyshale Clave/shale Hard shale Barren sand 

sand, and gravel or^adobe" or"shell or sandstone 

FIG. 17. Northwest-southeast sections along the lines S-L and S'-L', Pis. XVIII, XIX, Salt Lake fi

of occurrence of the oil-producing strata
190 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

thickness and composition in the different wells. This is to be 

expected, since individual layers in surface outcrops of similar beds in 

the Los Angeles region undergo important changes of thickness and 

gram within remarkably short distances. The upper oil sand on the 

northwest side of the flexure appears to become less and less impregnated with petroleum as it approaches the apex of the flexure. This 

condition is probably due to structural causes, such as the loss of the 

oil through fractures, although it may possibly be accounted for by a 

slight change in the grain of the sand near the flexure. The same 

beds, however, continue to carry considerable quantities of gas as 

they pass over the line of the disturbance.

The "main sand," which yields the bulk of the oil, is apparently 

fairly constant over a large part of the field. This sand is approximately 100 to 125 feet thick, rather coarse-grained, and highly 

impregnated not only with oil but with gas also. The tapping of the 

main sand usually results in the production of a "gusher," owing to 

the great pressure under which the gas is confined. The retention of 

the oil and gas in this sand is due to the presence of an overlying 

bed of impervious "shell," capped by 50 feet or more of hard clayey 

shale. The gravity of the oil in the same stratum is said to be different at different points down the dip. An illustration of this is found 

in a series of four wells runnmg across the strike of the oil sand in the 

northern part of the field. The well highest up on the dip yields 14° 

oil; the next lower down, about 150 feet from the first, 15°; the third, 

150 feet from the second, 16°; and the fourth, or lowest of the series, 

100 feet from the third, 17°.

 The two following well sections, one near the flexure, the other 

farther away and down the dip from it, are typical of the Salt Lake 

field: .

Typical well log near the flexure, on its northwestern flank, Salt Lake field. 

[Elevation about 225 feet; clip of strata approximately 40°.]

Clay....................................................................................

Sand and gravel ............................. ...... .....

"Adobe" (sandy shale) .................................................................

"Adobe," with salt water at base................................ . . .................

Clayey shale; 2-foot "shell" at 275 feet. ...............................................

"Adobe:" considerable water. .........................................................

Thickness.

Feet. 

36

24

30

70

 90

12

13

85

38

 47

41

19

21

106

40

29

94

5

118

Depth.

Feet. 

36

60

90

160

250

262

275

360

398

445

486

505

526

632

672

701

795

800

918
LOS ANGELES DISTRICT: SALT LAKE FIELD. 191

Typical vjell log near the flexure, on its northwestern flank, Salt Lake field Continued.

"Adobe;" layer of soft clayey shale at 960 feet. ........................................

Fair showing of oil in'"aclobe;" small "shell" at 1,075 feet............................

Shale and oil sand; considerable oil. ..... ...........................................

Shale; gas increasing; oil ..............................................................

Shale and "adobe-" lots of oil. ..........................................;.............

Passed through pulverized slate from 1,310 to 1,315 feet, light oil showing under this . .

Shale.... ...............................................................................

"Adobe;" oil coming up on bit; gas flow heavy; well filled for 400 feet with mud.water,

Light oil; large amount of gas; well filling rapidly with oil within 100 feet of top; large 

''shell" at 1,495 feet, under this the heavy flow of gas and oil; another shell at 1,505

Thickness.

' Feet. 

42

22

40

29

25

24

10

22

40

. 44

9

5

20

18

28

12

11 

19

4

39

19

5

34

54

12

14

17

Depth.

Feet. 

960

982

1,022

1,051

1,076

1,100

1,110

1.132

1,172

1,216 i 991

1,230

1,250

1,268

1,296

1,308

1,319 

1,338

1,342

1,347

1,386

1, 405

1,410

1,444

1,498

1,510

1,524

1,541

Oil /one, 490-4- fo.et (1,051 to 1,541 + ); thickness of producing sands, 347+ feet.

Typical well log 1,500 feet northwest of the flexure, Salt Lake field. 

[Elevation about 200 feet.]

Thickness.

P£t. 

50

750

3

297

2

163

470

20

30

10

20

20

2

123

10

91 '

10

10

86

129

150

10+

Depth.

Feet. 

50

800

803

1,100

1,102

1,265

1,270

1,740

1,760

1,790

1,800

1,820

1,840

1,842

1,965

1 Q71

2 000

2,010

2,020

2,106

2

OOC

2

OQC

2,g95+

Oil zone, 495 feet (1,740 to 2,235); thickness of producing sands, 337 feet.

AREA SOUTH AND SOUTHEAST OF THE LAGOON.

The underground geology in the area south and southeast of the 

lagoon is similar only in a very general way to that of the area to 

the north. The dip of the strata is probably toward the south or
192 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

southeast, although there are some indications of steep northerly 

dips immediately southeast of the lagoon. The superficial or Pleistocene deposits become thicker and coarser toward the southeast, 

those in the SE. \ sec. 28 attaining a thickness of 190 feet and consisting of clay in the upper 20 feet and sand and gravel in the lower 

portion. Deposits of asphaltum appear to be common at the base 

of the Pleistocene, and in at least one of the wells heavy oil was 

encountered not far below the middle of the formation. (See fig. 

17.) Water is usually found in these superficial beds, as in the area 

north of the lagoon.-

From the base of the Pleistocene down to the bottom of the deepest 

wells the rocks appear to be largely cla}^ey shale, interbedded at 

varying intervals with hard " shell" layers. Some sandy beds and 

a few pebbly lenses are also encountered in drilling. Indications 

of oil are abundant throughout certain horizons of the shale, but no 

really important productive sands have yet been found in the area. 

The wells near the lagoon on the south strike moderately productive 

sands between 700 and 1,000 feet, while those somewhat farther 

away get good showings of oil at less depths. In the territory a mile 

or so southeast of the lagoon the shale contains .here and there thin 

oil-bearing strata beneath the "shell" beds from'400 feet down, but 

nothing approaching a pay sand has been reached here. Salt water 

is reported as very troublesome below a depth of about 500 feet in 

this last locality. It is also found in most of the other wells of the 

southern area. The wells near the lagoon usually yield flowing 

water.

The three following logs are characteristic of their respective 

localities.

Log of well near ike middle of the north line o/ sec. 28, T. 1 8., E. 14 W. (immediately 

southeast of the lagoon), Salt Lake field.

[Elevation, 175 feet.]

Clayey shale; occasional layers of hard "shell" averaging 2 feet in thickness and

Thickness.

Feet. 

40

40

620

5

765

730

Depth.

Feet. 

40

80

700

705

1,470

2,200
LOS ANGELES DISTBICT : SALri: LAKE FIELD. 193

Log of well in the eastern part of the SE. J sec. 28, T. 1 S., R. 14 W. (1 mile southeast of the

lagoon), Salt Lake field.

[Elevation, ISO foot; dip approximately 20°.]

Sand 'and a little heavy oil (asphaltum) ......................................... . .

" River " sand having excellent quality but small quantity of light oil ................

Thickness.

Feet. 

28 

100 

45 

127 

4 

226 

4 

166 

6 

229

300

5 

55 

15 

81

Depth.

Feet. 

28 

128 

173 

300 

304 

530 

534 

700 

706 

935 

940 

1,240 

1,245 

1,300 

1, 315 

1, 396

Loy of well in tlie western part of the NW .\ sec. &?, T. .1 S., R. 14 W. (1 mile south-southwest of the lagoon), Salt Lake field.

\V ater sand containing heavy oil (asplialtum) . . ......................................

Heaving sand (gas); little water; no oil; carries considerable quantities of pebbles. . 

Blue clayey shale interbcdded with beds of sand and pebbles 1 foot or so in thickness 

carrying oil; richest horizon at about 700 feet. ....... .............................

Thickness.

Feet. 

90

90

325 

358

Depth.

Feet. 

90

180

505 

8fi3

STRUCTURE.

Owing to the almost complete absence of surface evidence in the 

immediate vicinity, the determination of the local structure in the 

Salt Lake field depends largely on the interpretation of the well logs. 

Unfortunately, not all of these were available at the time of the 

writer's visit to the field, so that the conclusions reached, although 

probably correct in the main, lack that detail and definiteness which 

is so desirable in an economic report of this sort. 

The strictty local structure of the field under discussion will be 

more fully comprehended if its relation to the general structure of the 

Los Angeles district as a whole is again briefty outlined. Practically 

all the productive oil sands of the different Los Angeles fields lie on the 

southern limb of a flexure, usually a more or less well-defined anticline, whose axis extends in a westerly direction to the region approximately half a mile north of Westlake Park, where it bends about 20° 

to the north and extends to a point about three-fourths of a mile 

southeast of Colegrove and something over a mile northeast of the 

Salt Lake field. Here it appears to bend again to the north, probably 

trending about N. 60° W. In the Los Angeles city fields, that is.
194 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

between the Catholic Cemetery and the Westlake Park region, the 

southern limb of the flexure dips normally at angles varying from 30° 

to 80°, while to the west, along that portion having a northwesterly 

trend, the dips flatten to 20° or 25°. The Salt Lake oil field is located 

on the northwestern flank of a minor, but probably somewhat complex 

fold or fault, or both, developed on the comparatively low-dipping 

southwestern limb of the major flexure just described. The dip of 

this flank of the local fold is reflected in a general way by the surface 

slope, which descends gently from the region of the present productive 

field northwestward toward Sherman. This slope probably indicates 

a Pleistocene or post-Pleistocene orogenic movement similar to but 

apparently of much less magnitude than that which produced the 

original flexure.

The exact nature of the local flexure is not known, but it is probably 

an anticline, more or less complicated by faults near the apex. Its 

axis extends in a general northeast-southwest direction. The logs 

of certain wells located southeast of the lagoon appear to indicate the 

presence of a minor anticline developed just south of the main flexure 

and separated from it by a fault. . Still other evidence suggests a 

local dome-shaped structure, or quaquaversal, having its summit in 

the region of the lagoon. The length of the Salt Lake flexure is 

unknown, although the available data seem to indicate its extension 

at least from a point near the center of the SE. \ sec 15, T. 1 S., R. 14 

W., as far as the lagoon in the SW. J sec. 21. Whether or not it continues farther to the southwest is problematical.

The large accumulations, of brea in the immediate vicinity of the 

lagoon and to the north and northwest of it, in addition to the constantly exuding oil and escaping gas over the same area, indicate some 

sort of a profound local disturbance or fracture in the underlying beds. 

If this disturbance has an extensive longitudinal dimension in a 

northwesterly direction from the lagoon, as some of the evidence suggests, then it may possibly cut off the Salt Lake flexure from a southwesterly extension beyond the lagoon. If, however, the structure in 

the vicinity of the lagoon is a local bulge or dome in the undertying 

beds it is quite likely that the Salt Lake flexure may have a considerable southwestern prolongation.

The contour lines on the map of the Los Angeles field (PL XIX) 

and the section shown in PI. XX, A-B, and in fig. 17 illustrate the 

writer's ideas concerning the local folds. From the map it will be 

seen that the strike of the oil sand probably swings around from a 

nearly east-west line in the region north of the lagoon to a direction 

slightly west of north in the NE. \ sec. 21. The dip of the sand in the 

region about the center of sec. 21 does not appear to be much more 

than 10° or 15°, but it increases rapidly in steepness toward the 

southeast up the rise and probably also toward the northwest, or 

down the dip.
LOS ANGELES DISTEICT : SALT LAKE FIELD. 195

The region immediately southeast of the Salt Lake flexure/although 

supporting some small producing wells one of which attains a depth 

of nearly 3,000 feet does not compare in productiveness with the 

territqry to the northwest. This condition may be explained on several hypotheses, the two most probable being either (a) that the Salt 

Lake flexure is accompanied by a fault which has dropped the productive sands on the southeast down out of reach of the drill, or 

raised them up to such an elevation that they were eroded away in a 

period subsequent to the faulting, or (6) that the continuation of the 

productive beds passes over the flexure (in this case an anticline) and 

down on the southeastern flank, but under conditions unsuited to the 

accumulation of oil in large quantities. The second hypothesis is 

represented diagrammatically by fig. 17.

Faulting may be responsible for the .cutting off of the upper oil 

sands immediately to the northwest of the axis of the flexure. If this 

be true it seems likely that the oil sand at the apex, which in fig. 17 

is correlated with the main oil sand of the productive field, should be 

correlated with the uppermost sands northwest of the fold. In this 

case the fault would have a downthrow of about 250 feet on the 

southeast.

DEVELOPMENT.

There are at present (February, 1906) between 75 and 80 productive or drilling wells in the Salt Lake field, belonging to the following 

companies: Salt Lake Oil Company, about 50 or°55; Arcturus Oil 

Company, 9; Utah Oil Company, 1 (these three companies controlled by the Associated Oil Company); A. F. Gilmore, 4; Pacific 

Light and Power Company, 4; E. P. Clark Oil Company, 7. In addition to the wells mentioned above, there are several comparatively 

small producers, belonging to the last-named company. These are 

located near the northern half of the line separating sees. 28 and 29, 

and are pumped intermittently. The wells north of the Salt Lake 

flexure vary from 1,200 feet to over 3,100 feet in depth, the deeper 

wells being as a rule the more productive and yielding the lighter oil. 

The individual wells produce from 20 to over 1,000 barrels a day, the 

average being about 100 barrels. Owing to the tremendous gas pressure nearly all the wells "gush 5 ' when they first come in, and it is said 

that one of the deep wells produced about 18,000 barrels a day for a 

short time after its inception. The gravity of the oil varies from 11° 

to 22°, the heaviest oil coming, it is said, from an isolated sand below 

the main productive zone. The average for the field is between 16° 

and 18°.

The large quantity of gas which comes from the wells is used mainly 

for the generation of power for operating and development, although 

a small amount is used in the field for domestic purposes.
196 OIL DISTKICTS OF SOUTHERN CALIFORNIA.

CONCLUSIONS CONCERNING FUTURE DEVELOPMENT.

Anyone at all familiar with the conditions of occurrence of petroleum in the California fields knows that any but the most tentative 

predictions as to the location of the oil are extremely hazardous. 

The following conclusions, based on the evidence in hand, although 

lacking definiteness for obvious reasons, may be of some assistance 

to those carrying on development in the Los Angeles fields.

CITY FIELDS.

All of the evidence, both geologic and that obtained by exploitation, indicates that the productive territory in the region of the 

eastern, central, and western fields has been largely developed, in 

fact overdeveloped, for the most part. It is very improbable, therefore, 

that prospecting outside of the already proved productive area, 

either immediately north or south of the oil belt, would result in 

success.

EAST OF LOS ANGELES RIVER.

Certain outcropping oil sands in the ravine occupied by the old 

Rapid Transit Railroad track indicate that oil-bearing strata underlie the region east of Los Angeles River and south of this ravine. 

A number of wells have been surik in this territory, however, and 

the greatest recorded production has been that of the Scott & Loftus 

well No. 1, whicK is said to have yielded 7 barrels of 17° B. oil per 

day.0 It is to be borne in mind that the deepest well so far sunk 

in this territory is less than 1,000 feet deep and that deeper wells 

farther down the dip than those already drilled may possibly yield 

better results, providing water does not interfere with their operation.

The structure of the Fernando sand and gravel in the area northeast of Brooklyn.Heights appears to be analogous to that in certain 

productive areas in the eastern field, as well as in the Puente Hills 

and Sulphur Mountain (Ventura County) fields. Moreover, the area 

mentioned is in the same formation and lies in the strike directly 

between the eastern field and the Whittier field. It does not seem 

improbable, therefore, that oil-bearing strata underlie the area 

here considered, although no direct evidence, such as seepages and 

brea, are known in the vicinity.

Were the thick deposits of Pleistocene and late Fernando sediments that conceal the structure of the older beds in the Raphetto 

Hills removed, these hills might be found to offer a remunerative 

field for exploitation with the drill.

f» Watts, W. L., Bull. California State Mining Bureau, No. 19, 1900, p. 73,
LOS ANGELES DISTKICT : FUTURE DEVELOPMENT. 197 

SOUTHWEST AND WEST OF LOS ANGELES.

It seems probable that the productive zone of the Salt Lake field 

extends northward and possibly a little westward from the territory 

now developed. Just where the northern limit is located is problematical, but it is quite certain that it_is considerably south of the 

base of the Santa Monica Mountains. Within this northern extension the beds in general dip to the west, and for this reason the most 

productive area will doubtless be found west of La Brea road. East 

of this road the oil sands approach the surface and consequently 

yield smaller quantities and heavier oil than the same beds farther 

down the dip.

The region southeast of the Salt Lake flexure, as shown by several 

wells, does not appear to offer many inducements for exploitation, 

at least in the immediate vicinity of the Salt Lake field. Farther 

east, however, in the region west and southwest of Westlake Park,

should deep wells strike a local flexure similar to that in the 

Salt Lake field they would doubtless yield large quantities of oil 

and gas. If the disturbance or fracture already mentioned as occurring in the vicinity of the lagoon does not have a northwestern extension, terminating the Salt Lake flexure and the productive zone on 

its northwestern flank, then it appears highly probable that deep wells 

will strike productive sand in the southern part of section 20 and 

the northern part of sections 29 and 30, T. 1 S., R. 14 W.

Outside of the territory mentioned in the preceding paragraphs 

there is little or no evidence of remunerative oil deposits in the 

immediate vicinity of Los Angeles. Were it not for the great thickness of Pleistocene sand and gravel, which cover the great Los Angeles 

Plain from the Santa Monica Mountains and Raphetto Hills to the 

ocean, it would be more than, likely that productive territory could be 

developed over this plain. At least .it is almost certain that the oilbearing strata underlie it, but whether or not the structural conditions are at any place conducive to the accumulation of gas or 

oil in paying quantities can be determined only by costly exploitation with the drill.

Bull. 309 07 14
198 OIL DISTRICTS OF SOUTHERN" CALIFORNIA.

PRODUCTION.

Owing to the large number of independent companies operating 

in the Los Angeles district, it has been impossible to obtain even 

approximately complete data concerning the annual production. 

However ^ the following figures derived from various sources are probably as nearly correct as any that are available:

Approximate production of petroleum in Los Angeles district, 1895 to 1905, inclusive.

Date.

1895"..............

18966..............

1897c.. ............

1898c... ............

1899 c.. .............

1900&.. ............

19016..............

1902 d.... ..........

1903d..............

1904*. .............

1905«..............

Field.

.....do.................................................................

.....do.................................................................

.....do.................................................................

.....do.................................................................

.....do.................................................................

Production.

Barrels. 

729, 695

900,000

i n?9 iwi

1, 168, 000

1,032,036

1,500,000

2,500,000

3,074,000

2,468,000

1, 199, 850

2,672,349

18,315,930

a Watts, W. L., Bull. California State Mining Bureau No. 19,1897, p. 21. 

f> Estimated by the writer.

c Watts, W. L., Bull. California State Mining Bureau No. 19,1900, p. 53.

d Estimate of central, eastern, and western fields by Charles A. Blackmar, city oil inspector; Salt 

Lake field estimated by the writer. 

 Statistics compiled by division of mining and mineral resources, U. S. Geological Survey.

STORAGE.

The storage facilities of the eastern, central, and western fields are 

largely confined to wooden tanks in the producing territory. Many 

of these are small, so that as a rule the operators are unable to hold 

their product for any considerable length of time. The storage capacity of the refineries in the city is also small, few of the individual 

refineries having a capacity of over 25,000 barrels.

The storage capacity of the Salt Lake field, on the contrary, is

about 390,000 barrels. Steel tanks, holding 20,000 to 55,000 barrels, 

are largely used in this field, although smaller wooden tanks are 

employed in a few instances.

TRANSPORTATION.

The oil from the city fields is in large part used locally, being delivered in tank wagons. No pipe lines of any great length exist in the 

city. The largest is the Union Oil Company's line, from First street 

and Lake Shore avenue, in. the central field, to the Southern Pacific 

Railroad at Palmetto and San Mateo streets, a distance of about '4 

miles.® An 8-inch pipe line connects the Salt Lake field directly with 

Los Angeles, and smaller lines run from some of the properties to 

tanks and racks on the line of the Los Angeles Pacific Electric Railroad immediately south of the fields.

0 Watts, W. L., Bull. California State Mining Bureau No. 11,1900, p.
BIBLIOGRAPHY OF SOUTHERN CALIFORNIA OILS.

The following is a bibliography of the principal articles referring to 

the oil industry of California and the geology of the southern California oil districts:

ANDERSON, F. M. Oil-yielding formations of Humboldt County; Bull. California

State Mining Bureau No. 19, Sacramento, 1900, pp. 161-166. 

ANONYMOUS. Description of the recently discovered petroleum region in California.

Tract. New York, 1865.

ANONYMOUS. Gas making with crude oil in California: Jour. Gas Light, April 28, 1903. 

ANTISELL, THOMAS. Geology of the Sierra Susanna and Monica: Pacific R. R. Rept.,

vol. 7, pt. 2, Washington, 1857, pp. 75-78. Plains of San Fernando, Los

Angeles, and San Bernardino: Idem, pp. 79-86. Bituminous effusions:

Idem., pp. 107-114, PI. V, figs. 2, 3. 

ARNOLD, DELOS and RALPH. The marine Pliocene and Pleistocene stratigraphy of

the coast of southern California: Jour. Geol., vol. 10, Chicago, 1902, pp.

117-138, PI. IV, figs. 1-7. 

ARNOLD, RALPH. The paleontology and stratigraphy of the marine Pliocene and

Pleistocene of San Pedro, Cal.: Mem. California Acad. Sci., vol. 3, San 

. Francisco, June 27, 1903, 420 pp., 37.pis,

 ' . The Salt Lake oil field near Los Angeles, Cal. In Contributions to Economic 

Geology for 1905: Bull. U. S. Geol. Survey, No. 285, Washington, 1906, pp. 

357-361, fig. 12.

ARNOLD, RALPH, and STRONG, A. M. Some, crystalline rocks of the San Gabriel Mountcins., California: Bull. Geol. Soc. America, vol. 16, Rochester, N. Y., April, 

1905, pp. 183-204, 2 maps.

BLACKMAR, CHARLES A. Register of oil wells, with map, Los Angeles city. Register 

California State Mining Bureau, Sacramento, 1904.

BLAKE, WILLIAM P. Geology and natural resources of the region from Mojave River, 

by Williamsons Pass, to San Fernando and Los Angeles; Los Angeles to San 

Bernardino and Cajon Pass: Pacific R. R. Rept., vol. 5, pt. 2, Washington, 

1856, pp. 65-88, 6 figs., PL VI.

BOWERS, STEPHEN. Geology of Ventura County: Eighth Ann. Rept. California State 

Mining Bureau, for 1888, Sacramento, 1889, pp. 679-690.

COOPER, A. S. The genesis of petroleum and asphalt in California: Sci. Am. Suppl., 

Sept. 2, Dec. 30, 1893; California Mines and Minerals, San Francisco, 1899, 

, pp. 114-174, 18 figs.; Bull. California State Mining Bureau, No. 16, Sacramento, 1899, 89 pp., 29 figs.

COOPER, H. N. Chemical analyses of California petroleum: Bull. California State 

Mining Bureau, No. 31, Sacramento, 1904a sheet.

COOPER, J. G. Lists of fossils from the oil-bearing formations of California. In Watts, 

W. L., The gas and petroleum-yielding formations of the central valley of 

California: Bull. California State Mining Bureau, Sacramento, 1894, pp. 7, 

10, 25, 38-40, 43, 49, 53-59, 62-65.

 . Lists of fossils from the oil-bearing formations of California. In Watts, W. L., 

Oil and gas-yielding formations of Los Angeles, Ventura, and Santa Barbara 

counties: Bull. California State Mining Bureau No. 11, Sacramento, 1897, 

pp. 79 -87.

199
200 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

CRAWFORD, WILLIAM H., and HOUGH, EDWARD S. See Hough, Edward S. 

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DEANE, C. T. The oil industry of California from a commercial standpoint: Am. Gas

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ELDRIDGE, GEORGE H. The asphalt and bituminous-rock deposits of the United

States: Twenty-second Ann. Kept. U. S. Geol. Survey, pt. ^Washington,

1901, pp. 209-452, Pis. XXV-LVIII, 52 text figs.

 . Petroleum fields of California.. In Contributions to Economic Geology for 

1902: Bull. U. S. Geol. Survey, No. 213, Washington, 1903, pp. 306-321.

 . Geology of California oil fields. In The production of petroleum: Mineral

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207. 

FAIRBANKS, H. W. Geology of San Diego County, also portions of Orange and San

Bernardino counties: Eleventh Ann. Rept. California State Mining Bureau,

Sacramento, 1893, pp. 76-120.

 . Notes on a breathing gas well: Science, new ser., vol. 3, New York, 1896, pp. 

693-694.

 . Some notes on the petroleum deposits of California: Min. and Sci. Press, vol. 

78, San Francisco, 1899, p. 533.

 . The oil-yielding formations of Monterey, San Luis Obispo and San Benito 

counties: Bull. California State Mining Bureau, No. 19, Sacramento, 1900, 

pp. 143-150.

GOODYEAR. W. A. Petroleum, asphaltum, and natural gas of California, in the counties south of the Bay of San Francisco: Seventh Ann. Rept. California State 

Mining Bureau, Sacramento, 1888, pp. 63-114.

HAYES, C. W., and KENNEDY, WILLIAM. Oil fields of the Texas-Louisiana gulf coastal 

plain: Bull. U. S. Geol. Survey No. 212, AVashington, 1903, 174 pp., Pis. IXI, figs. 1-12.

HOUGH, EDWARD S., and CRAWFORD, WILLIAM H. Report of recent oil-burning installations on the Pacific coast: Marine Engineering, September, 1902.

HOWARD, JOHN L. Fuel conditions in California: Am. Gas Light Jour., August 25, 

1902; Jour. Electricity, November, 1902.

HUDSON, ED. J., and MABERY, CHARLES F. See Mabery, Chas. F., 1900-1901.

HUNT, A. M. California petroleum and its use as fuel: Jour. Electricity, May, 1903.

JACKSON, C. T. The oil interest of southern California: San Francisco Bulletin, July, 

1865.

KENNEDY, WILLIAM, and HAYES, C. W. See Hayes, C. W., 1903.

LAKES, A. California asphaltum: Mines and Minerals, vol. 20, Scranton, Pa., 1899, 

pg. 108-109.

 Oil fields of California: Mines and Minerals, vol. 21, Scranton, Pa., 1901, pp. 

467-470.

LENGFELD, FELIX, and O'NEILL, EDMOND. A study of California petroleum; preliminary notice: Am. Chem. Jour., vol. 15, Baltimore, 1893, pp. 19-21.

LOEW, OSCAR. Report on the geological and mineralogical character of southeastern 

California and adjacent regions: Ann. Rept. U. S. Geog. Surv. W. 100th 

Her. for 1875-6, Washington, 1876, Appendix H 2, pp. 173-178.

LYMAN, B. S. Bibliography of petroleum: U: S. Census Report, 1880, vol. 10, pp. 281 

et seq.; Ann. Rept. Geol. Survey Pennsylvania, 1886, p. 2.

MABERY, CHARLES F. Preliminary paper on the composition of California petroleum: 

Am. Chem. Jour., vol. 19, Baltimore, 1897, pp. 796-804.

MABERY, CHARLES A., and HUDSON, ED. J. On the composition of California petroleum: Jour. Soc. Chem. Ind., vol. 19, London, pp. 502-503; Am. Chem. 

Jour., vol. 25, Baltimore, 1901, pp. 253-297.
BIBLIOGRAPHY. 201

MARCOU, JULES. Report on the geology of a portion of southern California: Ann. Eept

U. S. Geog. Surv. W. 100th Mer. for 1875-6, Washington, 1876, Appendix

H 1, pp. 158-1.72. 

MEANS, JOHN H. Map of the Oil City oil fields, Fresno County: Bull. California State

Mining Bureau No. 15, Sacramento, 1899, sheet. 

MERRIAM, J. C. Lists of fossils from the oil-bearing formations of California. In Watts

W. L., Oil- and gas-yielding formations of California: Bull. California State

Mining Bureau No. 19, Sacramento, 1900, pp. 218-224.

 Recent discoveries of Quaternary mammals in Southern California: 

 Science, N. S., vol. 24, no. 608, pp. 248-250, August 24, 1906.

OLIPHANT, F. H. The production of petroleum in the United States: Mineral Resources U. S. for 1900, U. S. Geol. Survey, Washington, 1901, pp. 129-134; 

idem for 1901, p. 58; idem for 1902, pp. 188-207; idem for 1903, pp. 166-178; 

idem for 1904, pp. 189-194.

O'NEILL, EDMOND. Petroleum in California: Am. Gas Light Jour., September 7,1903.

O'NEILL, EDMOND, and LENGPELD, FELIX. See Lengfehl, Felix.

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California. Geol. Survey, California, vol. 2, 1.882, appendix, p. 49-90.

 Petroleum in southern California: Science, vol. 23, New York, 1894, pp. 

74-78.

 Petroleum in its relations to asphaltic pavements: Am. Jour. Sci., vol. 47, 

New Haven, Conn., 1894, pp 28-34.

 On the nitrogen content of California petroleum: Am. Jour. Sci., vol. 48, 

New Haven, Conn., 1894, pp. 250-255.

 The asphalt question: Jour. Am. Chem. Soc., vol. 17, No. 1, Baltimore, Jan. 

19, 1895, pp. 1-9,

 On the use of acetone in the technical analysis of asphalt urn: Jour. Franklin 

List, vol. 141, Philadelphia, March, 1896, pp. 219-223.

 On the nature and origin of petroleum: Proc. Am. Phil. Soc., vol. 36, Philadelphia, No. 154, 1897, pp. 1-10.

 On the sulphur content of bitumens: Jour. Soc. Chem. Ind., vol. 16, No. 12, 

London, 1897, pp. 1-7.

 The technology of California bitumens: Jour. Franklin Inst., vol. 146, July, 

1898, pp. 45-54.

 The genesis of bitumens as related to chemical geology: Proc. Am. Phil. Soc., 

vol. 37, No. 157, Philadelphia, 1898, pp. 108-139.

 On the classification of crude petroleum: Jour. Franklin Inst., vol. 151,

Feb., 1901, pp. 114-124. 

PECKHAM, S. F. and H. E. The determination of sulphur in bitumens: Jour. Am.

Chem. Soc., vol. 21, No. 9, Sept., 1899, pp. 772-776. 

PRUTZMAN, PAUL W. Production and use of petroleum in California: Bull. California

State Mining Bureau No. 32,-Sacramento, 1904, 230 pp., 54 text figs, and 

. maps, 25 tables, 64 half-tones.

 Oil wells in Kern County. In Register of mines and minerals, Kern County: 

Register California State Mining Bureau, Sacramento, 1904, pp. 20-22, 4 

maps.

RICHARDSON, CLIFFORD. Petroleum from the Olindafield: Jour. Soc. Chem. Ind., vol. 

19, London, 1900, pp. 123-124.

 The petroleums of North America. A comparison of the character of those of 

the older and newer fields: Jour. Franklin Inst., vol. 16, 1906, pp. 57-70, 

81-128. . California fields, pp. 91-106.

ROPP, ALFRED VON DER. The use of crude oil in smelting: Min. and Sci. Press, November 29, 1902; Eng. and Min. Jour., January 10, 1903 (abstract).
202 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

SALATHE, FREDERICK. Resume of original researches, analyses, and refining methods 

of petroleum, mainly from the southern counties of California: Thirteenth 

Ann. Kept. California State Mining Bureau, Sacramento, 1896, pp. 656-661; 

Bull. California State Mining Bureau No. 11, Sacramento, 1897, pp. 73-78.

SHEEDY, P. The use of oil fuel on the Southern Pacific: Am. Engrv and R. R. Jour., 

July, 1902.

SILLIMAN, BENJAMIN. A description of the recently discovered petroleum region in 

California, with a report on the same. New York, 1865, 24 pp., 1 pi.

 Report upon the oil property of the Philadelphia and California Petroleum 

Company. Philadelphia, 1865, 36 pp.

 On petroleum in California: National Intelligencer, February 7, 1866.

 On naphtha and illuminating oil from heavy California tar (maltha): Am. 

Jour. Sci., 2d ser., vol. 43, New Haven, Conn., 1867, pp. 242-246.

STATE MINERALOGIST. Petroleum and allied products: Second Ann. Rept. California 

State Mining Bureau, Sacramento, 1882, p. 26: Fourth Ann. Rept., 1884, 

pp. 278-308; Fifth Ann. Rept., 1885, pp. 102-103; Seventh Ann. Rept., 

1888, pp. 10-56; Eighth Ann. Rept., 1889, pp. 25, 26, 159, 216, 339-341, 

349, 404, 483, 530, 534, 538, 547, 550, 554, 678, 686; Ninth Ann. Rept., 1890, 

pp. 55-56, 332; Tenth Ann. Rept., 1890, pp. 140, 163-164, 189, 207, 314, 

586-588, 606, 622; Eleventh Ann. Rept., 1893, pp. 31, 227, 237, 259, 371-372; 

Twelfth Ann. Rept., 1894, pp. 26-33, 348-358; Thirteenth Ann. Rept., 1896, 

pp. 35-45, 567-593.

STRONG, A. M., and ARNOLD, RALPH. See Arnold, Ralph, 1905.

VOGDES, ANTHONY W. A bibliography relating to the geology, paleontology, and mineral resources of California: Bull. California State Mining Bureau No. 10, 

Sacramento, 1896, 121 pp.; Bull. California State Mining Bureau No. 30, 

Sacramento, 1904, 290 pp. . WATTS, W. L. The gas- and petroleum-yielding formations of the central valley of 

California: Bull. California State Mining Bureau No. 3, Sacramento, 1894, 

100 pp., maps, text figs., and half-tones.

 Petroleum in California: Thirteenth Ann. Rept. California State Mining Bureau, Sacramento, 1896, pp. 570-593.

 Oil as fuel in Los Angeles: Thirteenth Ann. Rept. California State Mining Bureau, Sacramento, 1896, pp. 662-664.

 Oil- and gas-yielding formations of Los Angeles, Ventura, and Santa Barbara

counties: Bull. California State Mining Bureau No. 11, Sacramento, 1897, 

+94 pp., 35 figs.

 Petroleum in California: California Mines and Minerals, San Francisco, 1899, 

pp. 188-205,18 figs.

 Notes on the oil-yielding formations of California: Min. and Sci. Press, vol. 

74, San Francisco, 1899, pp. 144-146, 172-173.

 Oil- and gas-yielding formations of California: Bull. California State Mining 

Bureau No. 19, Sacramento, 1900, 236 pp., 26 text figs., 35 half-tones, 13 

maps.

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Bureau, Sacramento, 1888, pp. 179-191.

 Petroleum and asphaltum in portions of northern California: Seventh Ann.

Rept. California State Mining Bureau, Sacramento, 1888, pp. 193-202. 

WHITNEY, J. D. Geology of the Coast Ranges south of the Bay of Monterey and from

the vicinity of Los Angeles, south: Geol. Survey California, Geol., vol. 1,

Philadelphia, 1865, pp. 114-186. 

YOUNG, W. G. The present condition of the oil industry of California: Eng. and Min.

Jour., October 25, 1902.
PHYSICAL AND CHEMICAL PROPERTIES ,OF SOUTHERN CALIFORNIA OILS.

Compiled by RALPH ARNOLD.

INTRODUCTION.

The United States Geological Survey has done very little in determining the properties and composition of the California oils, and the 

information here given is compiled from published reports or the 

work of private individuals. By far the greater part of the analyses 

were made by members of the scientific staff of the California State 

Mining Bureau and are published in bulletins Nos. 3, 11, 19, 31, and 

32 of that bureau. The writer is largely indebted for data to Messrs. 

W. L. Watts, Frederick Salathe, EL N. Cooper, and Paul W. Prutzman. (See bibliography for list of papers, etc.)

GENERAL CHARACTER OF THE SOUTHERN CALIFORNIA

OILS.

C

GRAVITY.

The gravity of the oil from the wells in the Santa Clara Valley, Los 

Ang;eles, and Puente Hills districts varies from 10° to over 50° B. 

The heaviest oils are found in the Los Angeles field; the lightest oil 

is that from the unique wells in the gneiss of Placerita Canyon, east 

of Newhall. Certain wells in the Miocene shale of the Puente and 

Olinda fields (Puente Hills district) and the fields south of Sulphur 

and San Cayetano mountains (Santa Clara Valley district) yield oil 

of 30° to 35° gravity, while that in some of the wells in the Pico field 

(Santa Clara Valley district) is said to go as high as 40°. The greater 

part of the production from southern California, however, is oil varying from 18° to 24°.'

COLOR.

The crude oils from these districts are mostly black or brownish in 

color. The exceptions are the white oil of the Placerita Canyon wells, 

Santa Clara Valley district, and the greenish, light-gravity oils of the 

Sulphur Mountain and Pico Canyon fields, Santa Clara Valley district, and the Puente and Olinda fields, Puente Hills district. Greenish oil is also reported in one or two other instances.

203
204 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

COMPOSITION.

The following table gives the ultimate chemical composition of 

two California oils and, for comparison, of oils from Pennsylvania, 

Ohio, West Virginia, and Texas :

Ultimate composition of various crude oils.

Locality.

Oil Creek, Pa.» ................

Ohio 6 .........................

Specific 

gravity.

0.730

.840

.912

Nearest 

degree, 

Baumfi.

62

36

93 ^

c.

82.0

85.0

84.3

85X)3

86. 934

84.0

H.

14,8

13.8

14.1

12.30

11.817

12.7

0.

3.2

0

1.6

0

1.2

N.

60

92

1. 1095

1.7

S.

o:eo

i.75

0.4

By whom 

analyzed.

Do.

a Watts, W. L., Bull. California State Mining Bureau, No. 19,1900, p. 207. 

6 Jour. Soc. Chem. Ind., vol. 20, pp. 161 et seq. 

c Mixture of Ventura County oils.

FUEL AND GAS MAKING.

Oil is now largely used as a fuel in California in many places where 

coal was formerly employed, and is, in a measure, supplanting that 

commodity. The railroads and those electric lines not using power 

developed by water use oil almost entirely for fuel purposes. The 

gas companies also use it for the manufacture of gas, smelters for the 

smelting of ores, foundries for the heating and melting of metals, and 

other manufactories for nearly every purpose requiring the generation 

of heat.

Following is an analysis of a typical gas-producing oil from the 

Murphy Oil Company's wells, Whittier district, and an analysis of 

the gas derived from it: a

Results of crude oil test, Murphy Oil Company. 

Gravity at 60° F.. .\ ...............................................°B.. 20.5

Moisture and iionpetroleum substances.& ................................. None.

Flash point.&

Sulphur........................................................per cent.. 0.05

Residue (dry lampblack)...........................................do.... . 01.

Marsh gas (CHJ.................. 41.8

Nitrogen (N)..........'............' 2.8

Analysis of the gas produced from Murphy Oil Company's crude oil. 

[Based on the Lowe process 18-candlepower gas; 1,800 B. T. 17.]

Carbonic acid (C02).............. None.

Illuminants......................' 11. 2

Oxygen (0)...................... .4

Carbonic oxide (CO)............. 3.4 99. G

Hydrogen (H)........... r ........ 40

This gas gave over 600 British thermal units per cubic foot. It 

took 7.75 gallons of crude oil to produce 1,000 cubic feet of gas.

a Furnished by Mr. E. A. Bacon, of the Murphy Oil Company, Whittier.

6 Oil stored in tank eight months. Flash point in oil coming directly from ^yell, in five tests, J30°, 

88°, 90°, 92°, 94°.
GENEKAL CHAEACTER OF THE OILS. 205

PRODUCTS OF REFINERIES.

 Sixteen refineries use the oil from the three districts under discussion, and as the natural product varies in gravity from 10° to 35° or 

40°, the resultant distillates are varied: The higher-grade oil produces gasoline, benzine, kerosene (" water white"), No. 1 and No. 2 

distillates, stove distillate, and a residuum of fuel and road oil. 

The heavier oils, those under 21° or 22°, yield No. 1 and No. 2 distillates, stove distillate, lubricating, fuel, and road oils, with a residuum 

of asphalt.

The No. 1 and No. 2 distillates are used mostly in gas engines in 

many places for irrigation plants. No. 1 is suitable for engines under 

15 horsepower; 'No. 2 is best suited to the larger engines. The stove 

distillate is used in hotels, bakeries, and similar places where the fluid 

is consumed without steam pressure, while the regular fuel oils are 

usually forced into the fire boxes by means of special pressure burners."

The following is a list of the principal refinery products, together 

with the range in gravity of- each :

Refined products of California petroleum, b

Gasoline.......................... 68

Benzine......................... 62

Engine distillate.................. 56-40

Kerosene......................... 44-40

Stove oil.......................... 35-32

Gas oil........................... 30-28

Fuel distillate..................... 28-24

Neutral oils...................... 24-22

Light lubricants.................. 24-20

Engine oils...................... 20-18

Cylinder oils..................... 18-15

Crude lubricants, car oil, etc...... 17-15

ASTAJDY8ES. 

The following tables give, in a condensed form, the results of a large 

number of analyses and tests of oils from all the principal fields in the 

Santa Clara Valley, Los Angeles, and Puente Hills districts. The 

compiler wishes to reiterate the acknowledgment of his indebtedness 

to the California State Mining Bureau for the very free use he has 

made of its publications. The text of Bulletin No. 31 C of that bureau, 

is here copied in its entirety to explain Table 1 which is a part of that 

bulletin.

If a sample of ore containing gold and silver is sent to an assayer he will doubtless 

report practically the same results as would another assayer who had used an entirely 

different method of assaying. The same is true of two chemists determining the quantity of sulphur in pyrites, etc. But in organic analysis two different methods may 

vary as much as 10 per cent, from which it is obvious that data on oil given without 

the methods by which or the apparatus in which they have been obtained are almost 

useless and can not be duplicated or proved correct by another chemist. For this

"Sec Prutznmn, Paul W., Bull. California State Mining Bureau No. 32,1904, pp. 58 et seq. 

b Prutzman, Paul W., Bull. California State Mining Bureau No. 32, 1904, p. 187. 

c By H. N. Cooper, 1904.
206 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

reason it is considered proper to give the following description of the methods by which 

the data in the above table were determined.

Specific gravity. Two pycnoineters were used, one holding 25 c. c. and the other 1$ 

c. c., the larger one for the light oils and the smaller for the heavy oils. Both were 

calibrated with pure distilled water and the water content calculated to 4°. A heavy 

oil may be introduced into either pycnometer by first filling a small beaker and allowing a very small drop to fall into the pycnometer. This drop will carry with it a thread 

of oil, which may be increased to a stream, and thus the pycnometer can be filled without getting any air bubbles mixed with the oil. If the oil once touches the side of the 

neck it is an interminable job to fill the instrument. It would be better to clean out 

with gasoline and start over again. If the oil is too thick to pour, as above, then'use 

the little pycnometer, which is nothing more than a little bottle with a wide neck and 

a glass stopper carefully ground in. The little bottle is put next to the lip of the beaker 

containing the sample and the oil allowed to drain in. If the draining takes place 

slowly no air will get mixed with the oil. Then the-stopper is slowly squeezed in, 

until by turning-it, it grates on the ground glass of the bottle. The excess oil is wiped 

off with a rag, without undue handling of the bottle with the fingers. After weighing, 

the temperature is taken with an accurate thermometer and a correction of 0.0006 in 

specific gravity made for heavy oils and 0.0007 for light oils for each degree centigrade 

variation from 15° 15° being taken as normal.

Example: The little pycnometer full of sample No. 31 weighs 6.6195 at 18.5°. 

6.6195 wt. of pycnometer and oil. 

4.8413 wt. of pycnometer.

1.7782 wt. of oil in pycnometer. 

1.7782 (wt. of oil) -r-1.8431 (wt. of water) = .9648. 

.9648 + (3J X .0006) = .9669 sp. g. of No. 31 at 15°.

This seems a long process, but it is quickly carried out. I made 16 specific-gravity 

determinations in four hours, or an average of 1 in fifteen minutes. An error in the 

specific gravity causes a corresponding error in the distillation and also in the.calorific 

value per c. c., and too much care can not be taken in its determination. To take 

the gravity of heavy oils by the hydrometer is as long as this, and, moreover, very inaccurate. On first consideration it might seem that the specific gravity taken in a little 

bottle as small as 1.5 c. c. would be inaccurate, but I compared this with the 25 c. c. 

pycnometer and obtained results agreeing to 0.0001 in specific gravity, or practically 

identical.

Viscosity. There are many viscometers, but none of them are ideal. Nevertheless, 

I could not invent one that would answer all requirements and expect the public to 

use-it. It takes time to introduce a new idea or instrument. The Redwood viscometer seems to me to be the best now on the market, for the following reasons: It is the 

English standard; the tip is made of agate, and so will.not wear out; the tip is surrounded by heavy brass, thus keeping the oil in the tip at approximately the same 

temperature as the oil in the cup.

In the above data the viscosity has been taken at two temperatures at 15° C. (about 

60° F.) and at 85° C. (185° F.). It was taken at 15° C. because this is generally taken 

as "ordinary temperature," and at 85° C. because it is impossible to heat the contents 

of the Redwood viscorneter up to 100° O. (212° F.) with boiling water, so some lower 

temperature must be chosen. It is easy to heat the instrument up to 85° C. (185° F.), 

and, moreover, a pipe line may be heated to 85° C., but with great difficulty higher 

than this. Since our main object in finding the viscosity is to ascertain whether the 

oil can be piped without too great cost for pumping, the last consideration is important. 

To see whether it is practical to pass the oil through pipes 85° C. has been chosen.

It is customary to give the results in the number of seconds that it takes 50 c. c. to run 

through the instrument. To compare this with water (which runs through in 25 sec-
ANALYSES OP THE OILS. 207

onds) the results must be divided by 25. Through the instrument which I used water 

ran in 27$ seconds. Therefore I give two sets of results; one set consists of the number 

of seconds it took the oil to run through the instrument which I used; the other set, 

the same number of seconds divided by 27$. The data of the last set approximately 

tell how many more times-viscous the oil is than water at 15° C. (about 60° F.). Just 

before the test is made the level of the oil is made even with the tip.

Flash-point. Nothing can be more inaccurate than the open-tester, since it may be 

manipulated at will to give results varying by \0°. The most accurate of the open 

testers is liable to great variations in its results from drafts of air. The Abel closed 

tester gives results which may be duplicated within 1° or 2°. It is the English standard, and with the Pensky attachment it is the German standard. It seems to be perfect in every'respect for its purpose, i. e., for determining the flash from 60° F. to 

160° F. (Why not adopt it as the standard for California?) If the instructions for opening the slide are carefully followed, the Pensky clockwork for opening the slide is not 

necessary; it was invented to do away entirely with any tampering with results. In 

making the above determinations of flash point the directions given in Redwood's 

Manual were followed exactly. Since the flash was taken with reference to safety in 

transportation, the test was not made on those samples flashing below 15° C. (60° F.) 

and above 70°-'C. (168° F.). /

Calorific value. All the determinations were made with the Atwater bomb. The 

thermometer used was a Beckman, graduated in one one-hundredths, whose accuracy 

I tested. The basis was the average between Berthelot's calorific values for cane 

sugar and naphthalene. I carefully determined the value of the.se two substances. 

The naphthalene used was made by De Haen, Germany; its boiling point was between. 

79° and 80°, and it was melted before using. The sugar was three times crystallized 

cane sugar, whose composition by organic combustion agreed with the theoretical by 

0.03 on the H and 0.05 on the C; in other words, perfectly pure sugar. Before using, 

it was dried 'at 50° in the oven. My average of several results on sugar and naphthalene had to be increased by 1.08 per cent to make it the same as Berthelot's average for 

sugar and naphthalene, and all my results on petroleum are increased by the factor 

1.0108, which is evidently the correction factor of the bomb calorimeter plus my personal equation. My results are certainly within 0.5 per cent of the absolute, and on 

repetition the duplicates agree within 0.3 per cent.

Samples Nos. 1, 2, 3, 4, 6, 7, 9,10, 14,17,19, 25, 29, 38, 40, 41, 42, 43, 46, and 48 were 

taken from the top of the cans after the oil had stood for three or four months, and the 

calorific value found without preliminary treatment. Since Nos. 3, 4, 17, 29, and 40 

had water present, the calorific value obtained for these was increased by the same 

number of per cent as the oil held water; in other words, the calorific value was calculated on the dry sample. All other calorific values that were made of samples containing water first had the water removed by distillation. The calorific value of an 

oil containing water is useless for most purposes unless the percentage of water is given 

also;. for how can anyone get concordant results on a sample half water? (See sample 

No. 30.) Oil is bought by the gallon and not by the pound, and the column headed 

"Calorific value per c. c." gives the comparative value of the oils by volume.

Sulphur. The sulphur was determined from the sulphuric acid left over from the 

combustion in the platinum cup. The cup or lining as well as'the lid of the bomb was 

carefully washed into a beaker, the liquid filtered to about 100 c. c., BaCl2 added, and 

the precipitated BaS04 weighed and the sulphur calculated. The gases of combustion 

' I found to contain no sulphuric acid. (And of course no S02 , since HN03 was present.) 

I passed the gases slowly through glass wool soaked in TN7 KOH, and found almost no 

consumption of the alkalinity of the KOH, showing that all the H2S04 and HN03 

stuck to the lining.

Distillation. An ordinary i-liter glass distilling flask was used. The exit tube is 

bent upward for 2 inches just after leaving the neck of the flask; this is to facilitate
20S OIL DISTRICTS OP SOtJTHEBN CALIFOENIA.

filling and to intercept any liquid spurted out during the distillation. I do not give 

the measurements of the flask, because in California we have to take what we can get 

in the line of glassware. But if the flask holds 300 to 325 c. c. up to the bottom of the 

neck, the diameter of the neck is about one-fifth the diameter of the bulb, the exit tube 

joined to the neck halfway between the top of the bulb and the top of the neck, and the 

neck about one and one-half times as long as the diameter of the bulb, the flask will 

fulfill the requirements. To prevent condensation in the upward bend it is surrounded by fluffed asbestos fiber about half an inch thick. The exit tube should be 

30 inches long from the top. of the bend to the tip of the tube. The thermometer is 

placed so that the top of the bulb is level with the bottom of the exit tube. During 

the distillation up to the 250°-300° fraction the exit tube passes through a water condenser. After this fraction passes over the condenser is removed and the exit tube 

used as an air condenser.

The specific gravity of the sample is first determined; then the flask is placed on one 

pan and counterbalanced with shot. The balance must be accurate to 50 mg. with a 

300-gram load. Enough oil is poured in to make a volume of 200 c. c. (calculated from 

the specific gravity) at the temperature of the room in which the distillation is to take 

place. The condenser is attached, the 50-c. c. graduated cylinder put under the tip of 

the exit tube, and the oil is cautiously heated until all the water is driven over. In 

making the fractional distillation I do not recommend putting in any measured amount 

of gasoline or other light-boiling liquid to drive off the. water. I have never seen a 

sample that could not be fractionated in its original condition, if care and patience are 

used. The oil is ithen fractionated between the following temperatures: Up to 100°, 

100°-150°, 150°-200°, 200°-250°, 250°-300°, 300°-asphalt, asphalt. The flame is so 

regulated as to cause the oil to distil! over no faster than two drops per second. Just 

before the thermometer reaches the point where the distillation is to be stopped the 

flame is moderated to allow the thermometer to rise gradually to the stopping point. 

The flame is now removed to allow the temperature to fall, 20° for the 100° fraction, 

100° for the 300° fraction, and a proportionate fall for the fractions in between, and 

then heated up again. This is repeated until no more than three drops can be squeezed 

over. The receiver is then changed and the next higher distillate run over. An 

exception must be made with the 250°-300° fraction, if much cracking takes place. 

With some oils very varying results may be obtained for the 250°-300° fraction, because 

every time the temperature-goes up to 300° cracking takes place and more distillatepasses over. In such cases I have arbitrarily stopped at 50 c. c. and made a note to that 

effect in the tables (the fraction is marked [&]), or else I have kept the temperature at 

290° until the cracking had almost stopped. This last procedure is too long to be 

practical, and I recommend the former. The asphalt was run down to grade D. It 

was tested by running a looped wire down the neck of the distilling flask, drawing out 

a drop and testing it by chewing or by the finger nail. Of course, with such small 

quantities it does not make much difference in the results whether the asphalt is run 

down to grade C, D, or E. The asphalt is measured in this way: Fill the flask-with 

water to a mark on the neck; pour out the water and save for future use. Dissolve the 

' asphalt in waste lubricating oil (heat the flask over the flame) and remove the traces 

with gasoline and then with hot sulphuric acid and potassium bichromate. Dry, and 

pour back the water. Now run in water from a burette to the mark. The number of 

cubic centimeters run in represents the asphalt.
TABLE 1. Chemical analyses of southern Californ

[By H. N. Cooper, chemist. All samples taken direct from pump by Marion Aubury, fi

No. ofsample. I

1

?,

3

4

fi

7

g

10

11 

12

17

14

15

If.

IS

19

Name of company.

SANTA CLARA VALLEY 

DISTRICT.

fornia. 

.....do..................

..-.'..Ao. .................

.....do..................

.....do..................

Co.

Rwy. Co.

Rwy. Co. 

Union Oil Co. of California.

troleum Co.

Transportation Co.

fornia.

Pearl Oil Co............

County.

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do...... 

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

Location.

.....do................

.....do................

Sec. 12, T. 3 N., R. 20

W.

Santa Paula. 

.....do.. ..............

N., R. 21 W.

W.

R.22 W.

W.

Sec. 6, T.4N.,R.19W.

Santa Paula.

| W.

Sec.S,T.4N.,R.18W.

W.

Sec 9 T 3 N R 17 \V

o

Field.

.....do..........

yon.

yon.

.....do..........

.....do..........

Little Sespe Canyon.

tain.

Elevation.

Feet.

1,010

1,300

1,350

1,375

1,450

2,500

1,000

1,100

1,650

2,350

1,500

1,500

1.300

1,900

Shipping 

station.

.....do. ......

.....do.......

.....do.......

.....do.......

.....do.......

.....do.......

.....do.......

Ventura.

Santa Paula 

Piru.........

.....do.......

.....do.......

a Bull. California State Mining Bureau, No. 3
TABLE 1. Chemical analyses of southern California p

,2 *P<

1«4H

o 

6 

fc

?n

?i

m91

?4

?,5

?7

?S

9Q

30

01

3?

33

34

p.*;

Oft

07

00

QQ

40

4?

Name of company.

SANTA CLAKA VALLEY 

DISTRICT cont'd.

.....do..................

LOS ANGELES DISTRICT.

.....do. .................

\Vo«jt T aVo Oil C*r\

Co.

and Asphalt Co.

PUENTE HILLS DISTRICT.

Co.

Angeles.

ducing Co.

.....do. ........:........

County.

......do......

.:...do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do..v...

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

.....do......

Location.

Sec 7 T 3 N R 15 W

Sec.l6,T.3N.,R.16W.

SE. Jsee.'22, T. 2 S.,

R. 11 W.

T. 2S., R. 11 W. .....

Sec.22,T.2S.,R.llW.

W.

 Sec.8,T.3S.,R. 19 W .

Sec. 9, T. 3S., R. 9 W.

Field.

.....do..........

.....do..........

.....do..........

.....do..........

.....do..........

Whittle r. .......

.....do..........

.....do..........

.....do..........

Elevation.

Feet. 

1,400

1,700

200

440

440

360

250

250

425

435 265'

200

200

1 200

900

610

710

Shipping 

station.

.....do.......

.....do.......

.....do.......

.....do...;;..

.....do.......

.....do.......

.....do.......

.....do.......

.....do.......

.....do.......

Whittier. ....

Whittier. ....

.....do.......

.....do.......
oi

ft 

1

<t-t

O

1

1

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35

Time operated.

Since May 14, 1897 .....

Since Mar. 11, 1903. . . . .

Since Sept., 1902.......

Since Apr. 27, 1903 .....

Since July, 1902........

.....do......'...........

.....do...:.............

5 years. ................

Depth to 

oil sand.

j

Feel. 

600

48 

525 

500 

90, 200

600 

400-500 

240 

860, 1,100 

1,010

80 

900 

600 

930 

600 

930

1,000 

750 

800 

800 

900 

315 

' 800 

 750 

800 

750 

1.170 

305 

1,700 

1.300

Thickness 

of oil sand.

Feet.

160 

4-50

80, 100, 105 

100, 200 

......... .....

165

 10-50 

510 

100 

60-120 

35 

60-120

340 

10-100 

10-75 

100 

200 

55 

10-20 

1-20 

80 

30-60 

40 

75 

20-150 

200

Pipe line.

.....do.....-...-.-.-...

2J miles..... ........... 

7 miles

2J miles to Newhall . . .

24 miles to Newhall. . . .

.....do.................

.....do.................

.....do.................

.....do.................

......do.................

.....do.................

.....do.................

Line to San Pedro. . . . .

Gravity.

0 B.

28.9 

20.1 

19.7 

27.6 

29.7 

28.6

27.3 

13.4 

35.1 

30.9 

17.6 

14.6 

29.9 

28.4 

11.7 

17.8 

14.5 

37.3 

14.8 

29.9 

16.5 

14.3 

13.2 

17.9

. 12 

16.5 

14.2 

13.8 

12.6 

17.6 

10 

14.8 

15

Specific 

gravity 

of crude 

at 15° C. 

(about 

60° F.).

0.8814 

.9326 

.9351 

.8881 

.8767 

.8828

.8900 

.9759 

.8481 

.8701 

.9486 

.9685 

.8758 

.8838 

.9879 

.9474 

.9687 

.8367 

.9666 

.8758 

.9559 

.9699 

.9774 

.9467

.9860 

.9558 

.9706 

.9736 

.9815 

.9487 

1.0100 

.9669 

.9656

Flash.

-15 

68 

-15 

 15 

-15 

29

-15 

56 

-15 

 15 

 15 

+ 70 

-15 

-15 

+ 70 

35£ 

+70 

-15 

+ 70 

-15 

+ 70 

+ 70 

+ 70 

+ 70

+ 70 

+ 70 

+70 

+70 

+ 70 

-15 

+ 70 

+ 70 

67

A

Se

' 

Not accurate.
TABLE 1. Chemical analyses of southern California pet

o5 "p.

3

*o

*Zi

36 

37 

38 

39

40 

41 

42

QJ 

"ft

I

"o 

6 

£

1 

2 

3

4 

5 

.6 

7 

8 

9 

10 

11 

12 

13

Time operated.

9 months. . -

Since Feb., 1

Since Mar. 4, 

Since May 2J 

Since Jan. 18

J03........ 

1902......

, 1903.....

1902 .....

Depth to 

oil sand.

Feet.

675 

- 1,636 

450

1.648 

950

Thickness 

of oil sand.

Feet. 

5-15

220 

230

720 

57 

30-133

Pipe line.

18 mile 

2Jtmile 

4£ mile 

Union 

Pedi 

No lin 

Olinda

s to Chino 

s to Whit

s

;ier. . .

line to San

0.

3

Union line .....

Gravity.

0 B.

29.5 

20.7 

21.9 

19.3

' 19 

" 34 

23

Specific 

gravity 

of crude 

at 15° C. 

(about 

60° F.).

.8775 

.9291 

.9215 

.9378

.9399 

.8536 

.9147

Flash.

-15 

26 

17 

-15

44 

-15 

-15

 A

Se

 Distillation.

Percentage.

Water.

None. 

Trace. 

None. 

None. 

None. 

None.

None. 

None. 

None. 

None. 

.8 

9.3

Up to 100° 

C.

4 

0 

1.4 

8.9 

12.8 

0

9.3 

0 

15.3 

9.3 

3.1 

0

100°-150° 

C.

14.1 

.8 

8.7 

10.6 

13.8 

12.3

16.5 

0 

15 

10.2 

4.8 

0

150°-200° 

C.

9.1 

7.S 

8.3 

8.7 

9.9 

16.6

11.8 

6 

9.5 

9.8 

8.1 

5.9

200°-250° 

C.

9.3 

16.3

8.7 

7.3 

, 7.7 

14.3

7. 7 

6.1 

9.9 

8.8 

7.4 

15.3

250°-300° 

C.

10.1 

17.4 

8.9 

15.5 

9.8 

13.7

9.1 

18.9 

9.9 

11.4

o28.8 

6

300° C. to asphalt.

A.

43 

40 

40.1 

29 

30 

37.3

31.8 

30.8 

28 

34.9 

20 

23.7

B.

16.7

Asphalt.

9.8 

16.6 

20.7 

16.9 

14.8 

6.2

13 

38.1 

10.6 

13.2 

25 

23

Loss or

gain.

-0.6 

-1.1 

-3.2 

-3.1 

-1.2 

+ .4

- .8 

- .1 

-1.8 

-2.4 

-2 

- .1

Up 

" Much cracking on rehsating; percentage taken a
td

14 

15 

16

17

18

19 

?0

21m

23

24

?5

flfi

27

28

?9

30

31

32 

33

34

35

36 

37

38

39 

40

41 

42

None. 

None. 

4.2

3.5

None. 

6.1

None. 

.8

.2

30

.2

35.7

.5

1.6 3

44.6

None. 5

2.3

.2

None. 

None.

None.

None. 

1.3

None. 

None.

8.3

7.7 0

0 . 0

10.5 0

2.9 000000000

2.9 000

8 00

1.9 0

12.9 

4.2

10.4 

15.6 0

1.2 0

20.4 0

17.4 000000000

7.9 000

15.4 

4.2

6.9

6.2 0

15.3 

13.9

9.1 

10.7 0

fl 8

13.8 0

10.3 000000000

7.4 00

5.2

9 

9.6

8.8

9.2 

11.2

11.5 

8.9

8.8 

10.8 

12.8

11.2

11.5

13 

11.5

10.3 

7.6 4

6.6 0

9.7

6.9

5.9

4.6

7.8 

3.7

9.1

11.6

10.1 

14

12

8.1 

10.5

11.1 

9.7

10.2 

14 

16.8

a 21

12.2

11.1 

o22.7

13.5 

13.9

13.9

 12

17.5

18.6

15.8

19.4

14.1

7.7

17 

a 24. 1

19.5

a 25.1

14 

14.7

11.9

17.3 

15.5

9.6 

18.3

23.9 

15.3 

37

24

36.5

16.9 

32.1

20.8 

40

42.8

30.5

47.8

20.1

43.4

39.7

47.2

16.1

is: 2

20.9

37.6

28.5

23.1 

23

33.2

27.4 

28.3

19.5 

24.2

9.8 

8.9 

6.7

10.8

6.8

6.8 

2.5

9.5 

14.5

8.3

5.8

9.8

2.3

8.2

9.7

11.5

3' 8

5.7 

16.8

6.2

3.8 

9.9

6.5 5

16.6 

16.6 

22.6°

22.7

28.3

6.8 

22.6

10.9 

21.8

28.8

19.8

17.3

21.3

21.5

25.3

28.8

16.2

26.8 

44.2

26.5

28.4

13.1 

15.7

20.6

25.8 

23.1

11 

13.3

-2.9 

- .4 

+ .1

-1.1

-1.2

 . 7 

-2.5

-4.4

 -2

 1.9

 .8

-2

- .9

-2.6

-1

-1.1

- .5 

-2.1

1.2

1.6 2

.4

.3 

.2

2.6 

2.5

a Much cracking on reheating; percentage taken arb
214 OIL DISTRICTS OF SOUTHERN CALIFORNIA.

TABLE. 2. Proximate analyses of Southern California crude oils.a 

[By Paul W. Prutzman.]

vo 13*s

d 

fc

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13

14 

15

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26

27 

28 

29 

30 

31

Field.

SANTA CLAKA 

VALLEY 

DISTRICT.

Placenta ......

Torrey ........ 

.....do..........

Santa Paula...

Silver Thread.. 

Bardsdale..... 

Torrey........

LOS ANGELES 

DISTRICT.

Los Angeles . . .

PTTENTE HILLS 

DISTRICT.

.....do......... .....do..:......

Brea Canyon . . 

.'....do.........

Olinda......... 

.....do.........

.....do.........

.....do.........

Puente. .......

.....do.........

.....do."........

Whittier....... 

......do.........

.....do.........

.....do.........

County.

Los Angeles . . 

.....do........

.....do........ 

.....do........ 

.....do........

.....do........

.....do........ 

,:... do. .......

.....do........

.....do........ 

.....do........ 

.....do........

Los Angeles . .

.....do........ 

.....do........ 

.....do........ 

.....do........

.....do......:. 

.....do........

.....do........

.....do........ 

Los Angeles . . 

.....do........

.....do........

.....do........ 

.....do........

.....do........

.....do........

Section.

13 

4 

11

""8

17 

12

8 

8 

8 

1 

9 

9 

9 

9 

9 

35 

35

35 

26 

26 

26 

26

Township.

3N. 

3N.

4N.

TN."

4N. 

3N.

3S. 

3S. 

3S. 

3S. 

3S. 

3S. 

3S. 

3S. 

3S. 

2S. 

2S.

2S. 

.28. 

2S. 

2S. 

28.

« 

«

 16W. 

15 W. 

22 W.

" 18 W."

21 W. 

20 W.

9W. 

9W. 

9W. 

10W. 

9W. 

9W. 

9W. 

9 W. 

9W. 

10W. 

10W.

10W. 

11 W. 

11 W. 

11 W. 

11 W.

Taken 

from 

Tank . . . 

Well....

....do... 

Well.... 

....do...

Pipe line 

Well.... 

Tank . . . 

Well....

Tank... 

Well.... 

....do...

Well.... 

....do...

Well.'... 

Tank . . . 

Well.... 

....do...

....do... 

....do...

....do... 

....do... 

....do... 

....do... 

....do...

....do... 

....do...

....do... 

....do... 

....do...

Gravity (°B.).

17.2 

42.7

n

o

22.6 

23.9 

25.2 

25.6 

26. 

26.6 

26.8 

27.4 

28. 

28.1

15.1 

15.7

15.9 

20.3 

20.5 

23.3 

32.4 

32 8

33. 

33.4 

34.5 

26.8 

26.8

29.1 m 4

21. 

23.1 

23.2

Distillation.

Below 

150° C.

!lH

01 

PH

0 

51 

0

0 

7.2 

12.5 

10 

10 

13.8 

13 

19.4 

13 

16.6

0 

0

1 

Tr. 

3.4 

10.5 

21.7 

9A 8

24.8 

22.1 

22.9 

10.5 

12.5

21 

0

2.1 

5.2

4.7

W

t»+j

£ 

g

o

"48.'8

"54" 

53.7 

58.5 

56 

59.4 

54 

59.2 

61.6 

53.7

X

"55."8 

57 

59.1 

59 fi

60.9 

60.9 

62.1 

59.2 

58.8

58.2

55 

55 

57.3

150° C. to 

270° C.

1

s

PH

21.9 

43 

0

30 

26.7 

25.5 24- 

27 

32.4 

26.5 

26.1 

20.5 

23.6

20 

17.2

14 

23 

18.8 

25.5 

25.8 

917 7

27.6 

30.8 

27.9 

28 

29

24 

23.4 

23.9 

27.3 

24

PQ

0

'£ £

g O

36.9 

38

38.8 

38 

37.6 

41.5 

38.8 

40.8 

39 

40.1 

43.4 

39.8

30.2 

30.2

36.8 

41.2 

39.3 

39.9 

41.5 

40 7

42.8 

41.3 

43 

43.6 

42.4

41.4 

38.1 

38.2 

38.4 

39.3

Above 

270° C.

I

V

% 

PH

50.2 

4 

56.6 

53.2 

38.9 

50.2 

38 

44 

38.9 

45.9 

35.2 

40 

35.7

63.7 

54.1

41 

42.9 

47.6 

31.4 

41 8 

31 9,

31.4 

37.6 

33.4 

33

a

30.9 

45.3 

48.4 

44.7 

46.9

ffl

>> +j

1

(4 

O

25.5 

'247

"23" 

29.8

23

'25."5 

"247

"26."5 

"27."3

'22."6 

~24."5

a Bull. California State Mining Bureau, No. 32,1904, Table 25, opp. p. 198.
ANALYSES OF THE OILS. 215

TABLE 2. Proximate analyses of Southern California crude oils. 

[By Paul W. Prutzman.]

Distillation.

Asphalt.

Per cent.

25.9 

0 

41.7 

15.4 

25.5 

11.8 

25.3 

16 

12.9 

11.1 

18.8 

25.6 

21.1

13.3 

25.7

42 

32.1 

25.9 

31.6 

9 

16.7 

15.6 

8 

12.9 

26 

24

22.1 

27.3 

21.4 

20.2 

19.7

1 

0

D

"b"

D 

D 

D 

D 

D 

C 

D 

D 

D 

D

B 

D

D 

D 

E 

D 

D 

D 

D 

D 

D 

D 

F

D 

D 

D 

D 

E

I 

u

<D&.

0

2 

2 

1.7 

1.4 

1.7 

0 

2.7 

3 

2 

3.5 

.5 

.9 

3

3 

3

2 

2 

4.3 

1 

1.7 

.6 

.6 

1.5 

2.9 

2.5 

1.5

2 

4 

4.2 

2.6 

4.7

 Calculated analysis.

Total, 

gasoline.

 P 

§

PH

0.5 

52.3 

0 

1.5 

8 

13.3 

12.4 

11.4 

16.4 

14.3 

21.2 

15 

18.3

0 

0

1.2 

1.8 

4.4 

12.3 

24.3 

26 

27.6 

24.6 

25.7 

13.3 

15.4

22.9 

.7 

2.8 

6 

5.9

P? 

o

g

O

"49 

"54

54

53 

57 

55 

59 

' 53 

58 

60 

54

55 

54 

56 

58 

59 

60 

60 

61 

58 

58

58

"54 

55 

56

Kerosene.

"S

8H 

O

PH

12.1 

25.8 

0 

19.5 

16 

15.3 

19.2 

17.5 

24.3 

17.2 

18.3 

18.5 

16.5

4 

3

7 7

17.9 

12.3 

17.8 

20.6 

20.8 

24.8 

23.1 

25.1 

25.2 

24.7

17 

14 

14.4 

16.4 

15.6

ri

o

-P p 

S o

40 

40

"4! 

41 

41 

42 

41 

42 

41 

42 

42 

42

40 

40

40

42 

41 

42 

42 

42 

42 

42 

42 

42 

42

42 

41 

41 

41 

41

Middlings.

1

IH

CO

PH

23.8 

19.9 

24.3

24.5 

21.4

37.2

18.4 "is." 4

12.1

16.4

23.1 

"26." 6

P? 

o

f 

g

O

34.1

31.8

34 

"33.'7

32.7

32.5

31.8 

"33." 2

Lubricants.

tHO 

PH

35 7

0

32.3

35 1

19

42.5

34.7 

"29"

21.3

18

34.1 

'33."5

0

-J?I

O

17.5

'18.7

20.9

23

22.3

18.6 "ig.'s

c8 Q>

f|

"62."2 

48.8

52.1 

44.4 

53.9 

41.2 

40 

41.1

"68." 3

47.1 

46.2

"37." 3

"35."9 

31.4

42.8

'33"

36

54

"54."8

Asphalt.

i

u 3

H <U

PH

28.9 

0

41.7 

15.4 

25.5 

11.8 

25.3 

16 

12.9 

11.1 

18.8 

25.6 

21.1

13.3 

25.7

42 

32.1 

25.9 

31.6 

9 

16.7 

15.6 

8 

12.9 

26 

24

22.1 

27.3 

21.4 

20.2 

19.7

f

 P

1-1

(S

28.6

44.4 

18.1 

29.5 

13.7 

29.5 

18.8 

15.2 

13.1 

22.1 

29.1 

25.1

13.8 

28.1

45.9 

36.1 

29.2 

36.3 

10.7 

20.5 

18.1 

9.6 

16 

30.7 

28.5

26.3 

30.8 

24.2 

23.2 

22.6

tH

&

pL:

f 

o 

PH

94.9

153.1 

56.4 

93.6 

43.2 

92.9 

59 

47.4 

40.8 

69 

92.1 

77.7

46.7 

93.9

154.3 

117.9 

95.1 

116.2 

32.3 

61.7 

57.3 

29 

49 

95.7 

88.2

81.4 

100.2 

78.4 

74.3 

72.3

I 

o 1-1 <u

S)

01

3

2 

2 

1.7 

1.4 

1.7 

0 

2.7 

3 

2 

3.5 

.5 

.9 

3

3 

3

2 

2 

4.3 

1 

1.7 

.6 

.6 

1.5 

2.9 

2.5 

1.5

2 

4 

4.2 

2.6 

4.7

Remarks.

.White oil.

Green oil.

Greenish oil.

Greenish oil.

.................

Mixture from 

four wells.

,2

*M

O 

0

1

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13

14 

15

16 

17 

19 

18 

20 

21 

22 

23 

24 

25 

26

27 

28 

29 

30 

31
216 OIL DISTRICTS OF SOUTHERN/ CALIFORNIA.

TABLE 3. Distillation tests of southern California crude oils.a

[By W. L. Watts.]

of sample. No. 

1 

2 

3 

4 

5

6 

7 

8 

9 

10 

11 

12 

13 

14

15 

16

Well.

SANTA CLAKA VALLEY DISTRICT.

Tar Creek........

.....do............

Pico Canyon No. 4

LOS ANGELES DISTRICT.

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

Maltman.........

PUENTE HILLS DISTRICT.

.....do............

o

0

 o

D ^t 

°«

"o-S

>> +j

1 

O

23

23

22

25

40 

17

17

17

17

17

16

16

13

14

23

28

Naphtha.

100° C.

1

0

H 

<H 

fH

9.1

W

>> p

I

O

y.

69

125° C.

1

t-t

Q)

PH

10.4

W

0

>>

'£

03

FH

O

59

150° C.

4J

1

t-t

CD 

P4

7.6 

8.4 

Tr. "6 

9.3

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

10.2

«

0

£'£

 g 

O

60 

63

64 

54

61

Illuminating oil.

200° C.

4J§o

s . p-l

11

8 

6.9 

8.6 

13.4

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

Tr.

15.9 

13.5

«

£ £ 

g 

o

55 

58 

52 

54 

48

52 

55

250° C.

1 

o 

h

0)

£<

10.4 

10.4 

16.8 

10 

13.9

8 

7 

0 

9.6 

8 

1.6

2.2

Tr.

1

10.8 

12.2

« 

>>

1

tH 

O

41 

45 

45 

44 

41

38 

38 

39 

40 

42

45 

43

Lubricating oil.

300° C.

+j

a 

o

g

PH

12.4 

14.2 

9.7 

12.2 

8.3

13.6 

15.3 

16.8 

17.6 

12 

11.4 

11.2 

1.6

8

9.3 

10.2

n

!>>

1

O

34 

33 

38 

36 

35

32 

29 

31 

36 

32 

32 

30

31

35 

36

350° C.

4-i

g 

0

IH

0)

PH

6 

4 

6.6 

2.5

3 

7.1

8 

5 

4 

3.4 

7 

4 4

9.6

2.9 

8.3

P5

>> 

o3

O

29

"§3 

32

"27 

27

27

"29

33 

34

oBull. California State Mining Bureau No. 1-9,1900, pp. 203-205.
TABLE 4. Distillation tests of southern Californ

No. ofsample.

1 

2 

3 

4 

5 

6 

7 

8 

9 

10

11 

12 

13 

14

15 

16 

17

Source of sample.

SANTA CLARA VALLEY DISTRICT.

Fourfork wells Sespe field

Adams Canyon, Sulphur Mountain fielda.

.....do.....................................

LOS ANGELES DISTRICT.

.....do.....................................

.....do.....................................

PUENTE HILLS DISTRICT.

Murphy Oil Co.'s wells, Whittier field .....

Gravity of crude oil(°B.).

26.2

26.2

. 19.8

25.2

24 

27 

29 

24 

26 

25.2

14.3

19 

21

21 

21 

. 32

Specific gravity of crude 

oil at60°P.

.9090 

.8917 

.8805 

.9090

Gasoline 

(68° B.).

1

fH

O>

PH

5

10.4

4

8

ri

>> 

|

o

66

63

Naphtha 

or benzine 

(62° B.).

q

0>

h 

s>

pH

7.3 

6 

9.2 

14.1 

 5.2

Tr.

B 

>>

g 

O

60 

60 

60 

60 

60

Engine distillate 

(56°-40° 

B.).

1

tH

£

7 

6

14.5

11 

9

3.8 

4.5 

19.5

B 

>>

g 

O

50 

50

55

59 

50

Keros

(44°-4

B.

 jj 

a 

8

1

20

12

19.5 

17.1 

21.5 

26.4 

24.5 

28

13.8

6

7

8

13.5 

8.7 

12

a Greenish oil.

1, 2. .Furnished by Mr. Herbert Mills, secretary Happy Thought Oil Company, 1

3. 11, 13, 14, 15, 17. Furnished by Mr. James Jordan, Union Consolidated Refinin

4. 5, 6, 7, 8, 12. Salathe, Frederick, Bull. California State Mining Burea.u No. 11, 

9, 10. Prutzman, Paul W., Bull. California State Mining Bureau No. 32,1904, p. 
TABLE 5. California oil refineries using southern Ca

Company.

Pacific Coast Oil Co ...................

Union Oil Co ..........................

Location of plant.

.....do..............

.....do..............

.....do..............

.....do..............

.....do..............

.....do..............

Point Richmond . . .

County.

.....do..............

.....do..............

.....do..............

.....do..............

.....do..............

.....do..............

San Bernardino . : . .

.....do..............

.....do..............

Contra Costa .......

Still 

capacity 

for 

crude.

Barrels. 

1,075 

500 

200 

150 

600 

 1,000 

100 

500 

65,000

30 

600 

500 

2,400 

450 

800

Still 

capacity 

for 

rerunning.

Barrels. 

0 

250 

200 

150 

100 

1,000 

100 

135 

64,000

10 

100 

250 

2,000 

0 

350

Nu

b

o

sti

a Prutzman, Paul W., Bull. California State Mining Bureau, 

6 Figures doubtful. Owners refused information. 

c Owners refused information.
FOSSILS OF THE OIL-BEARING FORMATIONS OF 

SOUTHERN CALIFORNIA.

By RALPH ARNOLD.

INTKODTJCTION.

Many of the oil-bearing rocks of southern California contain the 

fossil remains of living organisms such .as plants, foraminifera, sea 

urchins or echinoderms, marine and fresh-water mollusks, crabs, fish, 

and some of the higher vertebrates. The marine mollusks, owing to 

their peculiar composition and habitat, are relatively much more liable to be preserved in the rocks than the individuals of ^most of the 

other groups, and, as a consequence, they are the most abundant of 

the organic remains, and therefore the most useful for purposes of 

correlation, not only in this region, but in all regions abounding in 

marine sediments.

A fossil may be the more or less altered remains of the plant or animal; it may be the empty mold from which all of the original material 

of the organism has been removed; or it may be the cast of the original 

form in hardened silt, sand, or some crystallized mineral which has 

replaced the organism.

It is well known that associations of species (fauna or flora) are 

governed by two important factors one of time and the other of 

environment. The fossil fauna of any formation, unless it be an unusually thick one requiring a very long time for its deposition, is generally 

fairly constant throughout for rocks of similar lithologic character, 

owing to the fact that faunas living at approximately the same time, 

under similar conditions, and in the same general region or biologic 

province are closely related or nearly identical. Conversely the 

faunas of the different kinds of rocks in the same formation and even 

of the same kind of rock in two different formations are. always more or 

less distinct. As the different marine sediments reflect the varying 

conditions of their deposition, so the faunas reflect their environment; fossils are usually found in a matrix whose deposition was governed by the conditions forming the environment of the fossils. Thus 

a deep-water fauna is usually found in shale or limestone, a shallowwater or littoral fauna in sandstone or gravel, and so on. Coarse 

conglomerates, owing to the disturbed conditions surrounding their

deposition, rarely contain recognizable fossils.

219
220 OIL DISTEICTS OF SOUTHERN CALIFORNIA.

It follows, then, that similar faunas from two or more different 

outcrops indicate in a general way the contemporaneity and similarity of conditions of deposition of the beds; that is, they indicate 

the same horizon or formation. The converse of this statement, 

however, is not always true, for it often happens, for example, that 

the shale fauna of one formation bears a stronger affinity to the shale 

fauna of a second formation either above or below it than to the fauna 

of contemporaneous sandstone or conglomerate within its own formation.

Some faunas are characterized by the predominance of one or 

more families or broader groups; some only by the occurrence or 

abundance of certain species. Analogous to the formations which 

contain them, certain faunas are distinctly isolated from others of 

the same region. A formation having an isolated, unique, or socalled characteristic fauna is the most easily identified and correlated, as the determination of only a few of its.species often suffices 

to locate it definitely. The correlation of those rocks whose fauna 

is not so distinctly separated from the fauna, of stratigraphically 

adjacent formations is much more difficult and generally requires 

some special training along; paleontologic lines. Fortunatety most 

of the formations in southern California contain fairly characteristic 

faunas, so that with a sufficient amount of identifiable material from 

any given stratum its correlation, or the determination of its relative 

position in the stratigraphic column, may be readily approximated.

It is a well-known fact that the only way to determine the relative 

position or age of any bed in a series where the rocks of the different 

formations are so much alike and the structure so complex as in. the 

southern California oil districts is by a determination of its fossil 

contents. Ordinarily lists of fossils are absolutely meaningless except 

to the few who have devoted at least a little time to the study of 

paleontology. But when these lists are supplemented by the figures 

of the species named it is an easy matter for anyone to find out for 

what each name really stands. The following plates are given to 

add meaning to the lists of fossils included in the text. The species 

figured do not represent all of those found in the oil-bearing formations of southern California, but rather those which are commonly 

found in or are characteristic of the principal formations there developed. It is thought that by means of these figures anyone will be 

able to locate approximately any bed in the geologic column if he 

can obtain from it a few recognizable fossils.

The fossils are arranged on the plates in the order of the occurrence 

of the rocks containing them, beginning with the oldest, the Eocene.
PLATES.

221
PLATE XXV.

EOCENE PELECYPODA.

(All figures natural size.)

FIG. 1. Venericardia planicosta Lamarck. U.S.N.M. 164973. Left valve; longitude 

84 mm. Eocene, Little Falls, AVash. This is the most widespread and 

characteristic Eocene species in the world. Found in the Sespe and 

Silver Thread districts, Ventura County.

FIG. la. Same specimen as fig. 1. View of anterior end of both valves.

FIG. 16. Same specimen as fig. 1. View of both valves from above. ,

FIG. 2. Cardium cooperii Gabb. U.S.N.M. 164998. A decorticated right valve; longitude 35 mm. Eocene, Rose Canyon. San Diego County. A common 

species in the Eocene of the west coast.

FIG. 2a. Same specimen as fig. 2. View of both valves from above.

FIG. 3. Meretrix hornii Gabb. Left valve; longitude 36 mm. Pal. Cal., vol. 2, pi. 30, 

fig. 78. A common species in the Eocene of the west coast.

FIG. 4. Modiolus ornatus Gabb. Right valve; longitude 38 mm. Pal. Cal., vol. 1, 

pi. 24, fig. 166. Another species found in most Eocene faunas of the 

west coast.
U. S. GEOLOGICAL SURVEY 1ULLETIN NO. 309 PL. XXV

EOCENE PELECYPODA.
PLATE XXVI.

EOCENE PELECYPODA AND GASTEROPODA.

(All figures natural size unless otherwise noted.)

FIG. 1. Pccten (Chlamys) calkinsi Arnold. Univ. California. An imperfect left valve;

altitude 45 mm. Eocene, Sisar Creek, Ventura County. 

FIG. 2. Same species as fig. 1. Univ. California. Imperfect right valve; altitude

29 mm. Same locality as fig. 1. 

FIG. 3. Pecten (Propeamusium) interradiatus Gabb. Left valve; altitude 25 mm.

Pal. Cal., vol. 2, pi. 33, fig. 98. Eocene shales at New Idria, San Benito

County, and in Silver Thread district, Ventura County. 

FIG. 3a. Same specimen as fig. 3. Interior of left valve. Pal. Cal., vol. 2, pi. 33,

fig. 98. 

FIG. 36. Same species as fig. 3. Outline of ears of right valve. Pal. Cal., vol. 2,

. pi. 33, fig. 98a. 

FIG. 4. Glycymeris veatchii Gabb var. major Stanton. U.S.N.M. 165003. Imperfect

left valve; longitude 30 mm. Eocene, Rock Creek, Los Angeles County.

Found in the lower Eocene (Martinez formation) in California. 

FIG. 5. Cardium brewerii Gabb. Right valve; longitude 51 mm. Pal. Cal., vol. 2,

pi. 24, fig. 155. Common in the Eocene (Tejon formation and equivalents). 

FIG. 6. Teredo sp. U.S.N.M. 164972. Type. Imperfect section of. tube, lateral

view; diameter 11 mm. Eocene, Sisar Creek, Ventura County. 

FIG. 6a. Same species as fig. 6. U.S.N.M. 164972. Cotype. Cross section of a

crushed specimen; maximum diameter 15 mm. Same locality as fig. 6. 

FIG. 7. Fusus remondii Gabb. Front view; altitude 41 mm. Pal. Cal., vol. 1, pi. 18,

fig. 36. Common in Eocene (Tejon formation and equivalents) on west

coast.

FIG. la. Same specimen as fig. 7. Magnified view of surface.

FIG. 8. Amauropsis alveatus Conrad. U.S.N.M. 165000. Front view of partially 

decorticated specimen; altitude 32 mm. Eocene, Rose Canyon, San 

Diego County. A characteristic Eocene gasteropod.

FIG. 9. Mono (Sconsia} tubercidatus Gabb. U.S.N.M. 364999. Front view of an 

imperfect and decorticated specimen; altitude 27 mm. Eocene, Rose 

Canyon, San Diego County. Perfect specimens have an anteriorly plicate 

plate over the inner lip; outer lip crenulate; revolving lines on surface.

FIG. 10. Cylichna costata Gabb. U.S.N.M. 165001. Front view of slightly imperfect 

specimen; altitude 18 mm., twice natural size. Eocene, Rose Canyon, 

San Diego County. Common in the Eocene (Martinez and Tejon formations and equivalents).
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XXVI

m

EOCENE PELECYPODA AND GASTEROPODA.
PLATE XXVII.

MIOCENE PELECYPODA AND GASTEROPODA.

FIG. 1. Pecten (Lyropecten) bowersi Arnold. Univ. California. Type. Bight valve; 

altitude 150 mm.; about two-thirds natural size. Lower Miocene, Santa 

Inez Mountains, Santa Barbara County. Also abundant at same horizon 

in Santa Monica Mountains and elsewhere. Left valve of this species 

more convex than right; otherwise very similar.

FIG. 2. Ostrea titan Conrad. U.S.N.M. 164987. Side view of both valves; altitude 

of large valve 131 mm.; two-thirds natural size. Lower Miocene, 3 miles 

south of Calabasas, Los Angeles County. This species is found in both 

the upper and lower Miocene, and often grows to a length of 20 inches (500 

mm.) (See PL XXXII, fig. 2.)

FIG. 3. Purpura edmondi Arnold. U.S.N.M. 164983. Type. Aperture view; altitude 19 mm.; about 1£ times natural size. Lower Miocene, 3 miles 

south of Calabasas, Los Angeles County.

FIG. 3a. Reverse view of same specimen as fig. 3; same enlargement.

FIG. 4. Chlorostoma (Omphalius) dalli Arnold. U.S.N.M. 164984. Type. Aperture 

view; latitude 12.5 mm.; 1$ times natural size. Lower Miocene, 3 miles 

south of Calabasas, Los Angeles County. A common species in this 

horizon.

FIG. 4a. Top view of same specimen as fig. 4.

FIG. 46. Base view of same specimen as fig. 4.

FIG. 5. Chlorostoma (Omphalius) dalli var. inornatus Arnold. U.S.N.M. 164986. 

Type. Top view; latitude 13.5 mm.; 1^ times natural size. Same 

locality as fig. 4.

FIG. 6. Chlorostoma (Omphalius) dalli var. subnodosus Arnold. LLS.N.M. 164985. 

Type. Top view; latitude 13 mm.; 1J times natural size. Same locality 

as Fig. 4.

FIG. 6a. Base view of same specimen as fig. 6.

FlG. 7. Cerithium topangensis Arnold. U.S.N.M. 164976. Type. Aperture view of 

imperfect specimen; longitude 23 mm.; 1\ times natural size. Lower 

Miocene, 3 miles south of Calabasas, at head of Topanga Canyon, Los 

Angeles County. A common species at the type locality.

FIG. 8. Cerithium topangensis Arnold. U.S.N.M. 164976. Cotype. Aperture view 

of imperfect specimen; longitude 13 mm.; 1J times natural size. Same 

locality as fig. 7.

FIG. 9. Cancellaria cf. condoni Anderson. U.S.N.M. 164981. Back view of imperfect 

specimen; altitude 21 mm.; 1J times natural size. Lower Miocene, 3 

miles south of Calabasas, Los Angeles County. This species appears to 

range from the San Joaquin Valley to the Santa Monica Mountains in the 

lower Miocene. 

226
U. S. GEOLOGICAL SURVE

MIOCENE PELECYPODA AND GASTEROPODA.
PLATE XXVIII.

MIOCENE PELEOYPODA AND "GASTEROPODA.

FIG. 1. Peden (Lyropecteri) magnolia Conrad. Univ. California. Imperfect right;

valve; altitude 14.5 mm.; about two-thirds natural size. Lower Miocene,

 Vaqueros formation, Ojai Valley, Ventura County. Characteristic of the

lower Miocene throughout central and southern California. The left valve

has narrow, more rounded ribs.

FTG. 2. Pecten (Lyropecteri) estrellanus Conrad. U.S.N.M. 164851. Left valve; altitude 97 mm.; about two-thirds natural size. Upper Miocene, Wildhorse 

Canyon, Mcnterey County. This species is usually abundant in both the 

lower and upper Miocene faunas of central and portions of southern California. Ribs of right valve broader and anterior ear notched; otherwise 

similar to left.

FIG. 3. Drilliasp. U.S.N.M. 164977. Type. Back view; longitude 13.5 mm.; about 

1£ times natural size. Lower Miocene, head of Topanga Canyon, 3 miles 

south of Calabasas, Los Angeles County.

FIG. 4. Macron merriami Arnold. U.S.N.M. 164982. Type. Aperture view; longitude 23 mm.; about 1^ times natural size. Lower Miocene, same locality 

as fig. 3. This species appears to range over central and southern California in the lower Miocene.

FIG. 4a. Back view of same specimen as fig. 4.

FIG. 5. Sigaretus perrini Arnold. U.S.N.M. 164979. Type. Aperture view of partially decorticated and imperfect specimen; altitude 18.5 mm.; about 1J 

times natural size. Lower Miocene, same locality as fig. 3.

FIG. 6. Turbo topangensis Arnold. U.S.N.M. 164980. Type. Aperture view; altitude 18.5 mm.; about 1^ times natural size. Lower Miocene, same 

locality as fig. 3. 

228
U. S. GEOLOGICAL SURVE 1ULLETIN NO. 309 PL. XXVIII

MIOCENE PELECYPODA AND GASTEROPODA.
PLATE XXIX.

MIOCENE ECHINOIDEA AND PELECYPODA.

FIG. 1. Pecten (Amusium) lompocensis Arnold. U.S.N.M. 164852. Cotype. Inte- 

. rior view, showing internal Ime; altitude 90 rnm.; about two-thirds natural size. Lower Miocene, Ojai Valley, Ventura County. This form, so 

far as known, is confined to the lower Miocene of Santa Barbara and Ventura counties.

FIG. 2. Ostrea cldridgei Arnold. U.S.N.M. 164986. Type. View of exterior of larger 

valve; altitude 14.7 mm.; two-thirds natural size. Lower Miocene, supposed equivalent of Vaqueros formation, Elkins ranch, east of Grimes 

Canyon, south of Filhnore, Ventura County.

FIG. 2a. Lateral view of same specimen as fig. 2. ' _

FIG. 3. Scutellafuirbanlcsi Merriam. U.S.N.M. 164963. View of top, showing details; 

maximum diameter 36 mm.; 1 £ times natural size. Lower Miocene, supposed equivalent of Vaqueros formation, near Torrey Canyon wells, southwest of Piru, Ventura County; abundant. This species is also found near 

the base of the Vaqueros formation in the Sespe district. Supposed to

be characteristic of the lower Miocene.

230
U. S. GEOLOGICAL SURVEY IULLETIN NO. 309 PL. XXIX

MIOCENE ECHINOIDEA AND PELECYPODA.
PLATE XXX.

MIOCENE ECHINOIDEA AND PELECYPODA AND GASTEROPODA.

(All figures natural size.)

FIG. 1. Venus (Chione) temblorensis Anderson. U.S.N.M'. 164989. Exterior of imperfect right valve; longitude 80 mm. Lower Miocene, head of Topanga 

Canyon, 3 miles south of Calabasas, Los Angeles County. LTsually abundant in the lower Miocene; a nearly related, possibly identical form found 

in the upper Miocene.

FIG. la. Top view of same specimen as fig. 1.

FIG. 2. Mylilus mathervsonii Gabb var. expansus Arnold. U.S.N.M. 164968. Type. 

Right valve; altitude 10.5 mm. Lower Miocene, supposed equivalent of 

the Vaqueros formation, near Torrey Canyon wells, southwest of Piru, 

Ventura County. This species is usually found in the faunas of the lower 

Miocene through central and southern California.

FIG. ?>. Scutdla fairbanksi Merriam. U.S.N.M. 164963. Same locality as fig. 2, but 

possibly at a somewhat lower horizon.

FIG. 4. Odnebra topangensis Arnold. U.S.N.M. 164995. Type. Back view; altitude 59 mm. Lower Miocene, Topanga Canyon, 3 miles south of Cakbasas, Los Angeles County. So far known only from this horizon. 

232
U. S. GEOLOGICAL SURVEY ULLETIN NO. 309 PL. XXX

MIOCENE ECHINOIDEA, PELECYPODA, AND GASTEROPODA.
PLATE XXXI.

MIOCENE PELECYPODA AND GASTEROPODA.

(All figures natural size.)

FIG. 1. Pexten (Lyropecteri) cmssicardo Conrad. TJ.S.N.M. 164967. Exterior of valve, 

showing characteristic sculpture; altitude 90 mm. Lower Miocene, Ojai 

Valley, Ventura County. This species ranges through the lower and 

upper Miocene, being commoner in the former in soiithern California, in 

the latter in central California. It is sometimes more convex than the 

figured specimen, and often shows concentric undulations of the disk.

FIG. 2. Pecten (Chlamys) sespeensis var. hydei Arnold. Collection of Delos Arnold. 

Type. Right valve, ear missing; altitude 46 mm. Lower Miocene, 

Lynchs Mountain, San Luis Obispo County. Found also in the Vaqueros 

formation, Little Sespe Creek, and, with Mylilus mathewsonii Gabb, in 

supposed equivalents of the Vaqueros formation near the Torrey Canyon 

wells, Ventura County.

FIG. 3. Pecten (Pseudamusiurn) peckhami Gabb. U.S.N.M. 164839. Bight and left 

valves in matrix; altitude of largest 17 mm. Monterey shale (middle 

Miocene), soiitheast of Pinole, Contra Costa County. The type of this 

species came from the Ojai Valley, Ventura County. It is the commonest 

form in the shales of the middle Miocene (Monterey, Modelo, and equivalent formations) and is also known from the Oligocene in the Santa Cruz 

Mountains.

FIG. 4. Neverita callosa Gabb. U.S.N.M. 164992. View from above, specimen

slightly tilted; maximum latitude 44 mm. Lower Miocene, head of 

Topanga Canyon, 3 miles south of Calabasas, Los Angeles County. 

Ranges through the Miocene. Common in the lower Miocene of southern 

San Joaquin Valley and the Santa Monica Mountains. 

FIG. 4a. Same specimen as fig. 4. View of base and aperture, showing characteristic

. shape of callous. 

234
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XXXI

MIOCENE PELECYPODA AND GASTEROPODA.
PLATE XXXII.

MIOCENE PELECYPODA, GASTEROPODA, AND CRUSTACEA.

(All figures natural size.)

FIG. 1. Pectcn (Hinnitcs) giganteus Gray. U.S.N.M. 164965. -Exterior of' right 

valve; altitude 90 mm. Lower Miocene, supposed equivalent of Vaqueros formation, gulch east of Wiley Canyon, southwest of Piru, Ventura 

County. A very variable species ranging from the lower Miocene to the 

Recent fauna.

FIG. 2. Ostrea titan Conrad. U.S.N.M. 164987. View of exterior of larger valve; 

altitude 131 mm. Lower Miocene, 3 miles south of Calabasas, Los Angeles County. A common form in the upper and, lower Miocene; often 

grows to a length of 20 inches (500 mm.) or more. (See PL.XXVII, fig. 2.)

FIG. 3. TrocMta costellata Conrad. U.S.N.M. 164994. View from above; maximum 

diameter 38 mm. Same locality as fig. 2. Common in the Miocene.

FIG. 4. Phacoides richthofeni Gabb. U.S.N.M.. 164978. Right valve; altitude 17.5 

mm. Same locality as fig. 2.

FIG. 5. Balamis concavus Bronn. U.S.N.M. 164971. Type. Lateral view; maximum latitude 26 mm. Lower Miocene or upper Oligocene, Little Sespe 

Creek, Veiltlira County. A very common species in this horizon.,

FIG. 5a. Same species as fig. 5. Top view.

236
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XXXII

MIOCENE PELECYPODA, GASTEROPODA, AND CRUSTACEA,
PLATE XXXIII.

MIOCENE PELECYPODA AND GASTEROPODA.

(All figures natural size.)

FIG. 1. Pecten [Chlamys] sespeensis Arnold. California State Mining Bureau. Cotype 

Portion of mold of interior of right valve; altitude 50 mm. Lower Miocene, Vaqueros formation, Sespe Canyon, Ventura County. A common 

species at the type locality; also found elsewhere in central and southern 

California in the lower Miocene.

FIG. la. Mold of interior of left valve of same specimen as fig. 1.

FIG. 2. Pecten (Chlamys) sespeensis Arnold. California State Mining Bureau. Plasto- 

. type. Cast of exterior of slightly imperfect left valve (young); altitude. 

18 mm. Same locality as fig. 1.

FIG. 3. Pecten (Lyropecten) vfiughani Arnold. Collection of Delos Arnold. Type. 

Right valve; altitude 37 mm. Lower Miocene, supposed equivalent of 

1 Vaqueros formation, Ojai Valley, Ventura County. .

FIG. 3a. Same specimen as fig. 3. Left valve.

FIG. 4. Dosinia ponderosa Gray. U.S.N.M. 1.64988. Imperfect right valve; altitude 

80 mm. Lower Miocene, 3 miles south of Calabasas, Los Angeles County. 

A common species from the lower Miocene to the Recent southern fauna

of the west coast.

FTO. 5. Pleurotoma (Dolichotoma) keepi Arnold. U.S.N.M. 164993. Type. Back 

view of imperfect specimen. Same locality as fig. 4. Found also in this 

horizon at several localities in southern San Joaquin Valley. 

238
U. S. GEOLOGICAL SURVEY

MIOCENE PELECYPODA AND GASTEROPODA.
PLATE XXXIV.

PLIOCENE PECTENS.

(All figures about two-thirds natural size.)

FIG. 1. Pecten (Patinopecteri) healeyi Arnold. U.S.N.M. 148012. Type. Exterior of 

right valve; altitude 121 mm. San Diego formation (Pliocene), San 

Diego County. A characteristic form in the lower Pliocene from' San 

Mateo County to the Mexican line. Left valve with narrow rounded ribs 

and intercalates; disk also less convex.

FIG. 2. Pecten (Lyropecteri) ashleyi Arnold. Univ. California. Type. Exterior of 

right valve; altitude 355 mm. Pliocene, Cerros Island, off Lower California. Also characteristic of the lower Pliocene, but so far known only 

as far north as Santa Barbara County. The left valve has slightly narrower ribs and no byssal notch in the anterior ear. 

240
BULLETIN NO. 309 PL. XXXIV

J

PLIOCENE PECTENS.
PLATE XXXV.

PLIOCENE PECTENS.

(Unless otherwise stated all figures are about two-thirds natural size.)

FIG. 1. Pecten (Chlamys) wattsi Arnold. California Acad. Sci. Type. Exterior of 

slightly imperfect left valve; altitude 66 mm. Lower Pliocene, Kreyenhagen's ranch, Fresno County. Also found in the lower Pliocene of 

southern California. Right valve with broader, flatter ribs.

FIG. 2. Pecten (Pecten} stearnsii Dall. U.S.N.M. 148008. Exterior of left valve; 

altitude 87 mm. San Diego formation (Pliocene), Pacific Beach, San 

Diego County. Not rare in the Pliocene. (See PI. XXXVI, fig. 4, for 

right valve.)

FIG. 3. Pecten (Pecten) bellus Conrad. Acad. Nat. Sci. Phila. 960. Exterior of right 

valve; altitude 80 mm.; about five-sixths natural size. Pliocene, Santa 

Barbara. Also found in Pliocene of Ventura, Santa Barbara, and adjacent counties. Left valve slightly concave, with narrower ribs than right; 

otherwise similar.

FIG. 4. Pecten (Plagioctenium} circularis Sowerby. U.S.N.M. 61246. Right valve; 

longitude 26 mm.; nearly natural size. Pleistocene, Ventura County. 

May also extend down into the Pliocene.

FIG. 5. Pecten (Pecten) vogdesi Arnold. California Acad. Sci. Cotype. Exterior of 

slightly imperfect left valve; altitude 74 mm. Pleistocene, Ventura 

County. Also occurs in supposed Pliocene near San Diego. Right valve 

very convex, with broad rounded ribs:

FIG. 6. Pecten (Playiodenium} cerrosensis Gabb. Univ. California. Exterior of left

valve (anterior ear slight broken); altitude 106 mm. Pliocene, Cerros 

Island, off Lower California. Also found in the Pliocene near Camulos, 

Newhall, and San Diego.

FIG. 7. Pecien (Pecten) auburyi Arnold. California State Mining Bureau. Type. 

Exterior of imperfect right valve; altitude 46 mm. Pliocene, Puente 

Hills, Los Angeles County. Left valve slightly concave, with ribs narrower than in right. . 

242 .
U. S. GEOLOGICAL SURVEY IULLETIN NO. 309 PL. XXXV

PLIOCENE PECTENS.
PLATE XXXVI.

PLIOCENE PECTENS.

(All figures about two-thirds natural size.)

FIG. 1. Pecten (Patinopecteii) caurinus Gould. Collection of Delos Arnold. Exterior 

of left valve; altitude 105 mm. Pliocene, Deadman Island, Los Angeles 

County. Specimens of this species measuring over 8 inches (200 mm.) 

have been found in the Pliocene of Ventura County. This form appears 

to be confined to the upper Pliocene and Pleistocene in southern California. Right valve more convex and with broader square ribs and 

plain concentric sculpture.

FIG. 2. Pecten (Chlamys) latiauritus Conrad. Collection of Delos Arnold. Exterior 

of right valve; altitude 25 mm. San Pedro formation (Pleistocene),-San 

Pedro, Los Angeles County. Known also from the lower Pliocene at 

Los Angeles.

FIG. 3. Pecten (Chlamys) latiauritus Conrad. Collection of Delos Arnold. Exterior 

of left valve; altitude 27 mm. Same locality as fig. 2.

FIG. 4. Pecten (Pecten) stearnsii Ball. U.S.N.M. 148008. Exterior of right valve; 

altitude 87 mm. San Diego formation (Pliocene), Pacific Beach, San 

Diego County. (See PI. XXXV, fig. 2, for left valve.)

FIG. 5. Pecten (Pseudamusium) pedroanus Trask. U.S.N.M. 164840. Exterior of 

right valve and young left valve; altitude of former, 22 mm. Lower 

Pliocene, Third street tunnel, Los Angeles. Also found in beds of 

supposed Miocene age in the Puente Hills and San Pedro.

FIG. 6. Pecten (Pseudamusium) pedroanus Trask. U.S.N.M. 164840. Exterior of 

imperfect left valve; altitude 30 mm. Same locality as fig. 5.

FIG. 7. Pecten (Chlamys) parmeleei Ball. U.S.N.M. 154479. Type. Left valve 1 

altitude45 mm.; abOUt five-sixths natural size. Pliocene, Pacific Beach, 

San Diego County. Also known in Pliocene of Puente Hills.

FIG. 8. Pecten (Chlamys) opuntia Dall. U.S.N.M. 107752. Type. Right valve; 

altitude 33 mm.; about four-fifths natural size. Pliocene, Pacific Beach, 

San Diego County. Also common in Pliocene at Santa Barbara and 

elsewhere in southern California.

FIG. 9. Pecten (Pecten) merriami Arnold. California State Mining Bureau. Type. 

Exterior of imperfect left valve; altitude 110 mm. Pliocene, Piru 

Creek, Ventura County. Characteristic of the lower Fernando horizon 

(lower Pliocene or upper Miocene) so far as known. Right valve convex, 

with broader squarer ribs. 

244
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XXXVI

PLIOCENE PECTENS.
PLATE XXXVII.

PLIOCENE ARC AS.

FIG. 1. Area camuloensis Osmont. California State Mining Bureau. Type. Right 

valve; altitude 89 mm. Fernando formation, lower Pliocene or upper 

Miocene, 1 mile north of Camulos, Ventura County. So far as known this 

species is characteristic of the lower horizon of the Fernando formation. 

Also( reported from the Puente Hills.

FIG. la. End view of same specimen as fig. 1.

FIG. 1&. Portion of surface of same specimen as fig. 1, enlarged, showing nodose ribs.

246
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XXXVII

^-^3O ,-£ ^-rfea&r

PLIOCENE ARCAS.
PLATE XXXVIII.

PLIOCENE PELECYPODA AND GASTEROPODA.

(Unless otherwise stated all figures natural size.) '

FIG. 1. Area multicostata Sowerby. U.S.N.M. 12574. Right valve; longitude 101 

mm. Recent, San Diego. Found in the lower Pliocene (Fernando 

formation) in the Puerile Hills, Orange County, and in the vicinity of 

Los Angeles. _ _ .

FIG. 2. Cardium quadrigenarium.Conrad va,v.fernandoensis Arnold. U.S.N.M. 164947. 

Type. Imperfect left valve; longitude 58 mm. Lower Pliocene (Fernando formation), Elsmere Canyon, near Newhall, Los Angeles County. 

A common variety in the lower Pliocene. The typical form with 44 

ribs and less obliquity is found in the Recent.

FIG. 2a. Same specimen as fig. 2. View of umbos from above.

FIG. 3. Area trilineata Conrad. U.S.N.M. 164948. Right valve of medium-sized 

 . specimen; longitude 40 mm. Same locality as fig. 2. A common species 

in the Pliocene of California. Also appears to extend down as far as the 

middle Miocene (Mo'nterey).

FIG. 3a/Same specimen as fig. 3. Umbos and hinge area viewed from above.

FIG. 4. Area trilineata Conrad. Portion of an adult left valve, showing the more complex sculpture of the ribs' in the later stages of growth; altitude 60 mm. 

Same locality as fig. 2.

FIG. 5. Leda taphria Ball. U.S.N.M. 164952. Right valve; longitude 36 mm.; 

twice natural size. Same locality as fig 2. This species is common from 

. the Pliocene to the Recent fauna in the California province.

FIG. 5a. Same .specimen as fig. 5. View of umbos from above.

FIG. 6. Neverita recluziana Petit. U.S.N.M'. 164960. Back view; latitude 25 mm. 

Same locality as fig. 2. A common species from the Pliocene to the 

Recent fauna; also probably occurs in the Miocene. 

248
U. S. GEO-OGICAL SURVEY BULLETIN NO. 309 PL. XXXVIM

PLIOCENE PELECYPODA AND GASTEROPODA.
PLATE XXXIX.

PLIOCENE BRACHIOPODA AND PELECYPODA.

(All figures natural size.)

FIG. 1. Ostrea veatchii Gabb. U.S.N.M. 153827. Exterior of valve; altitude 90 mm. 

Lower Pliocene, San Diego. An abundant and characteristic species in 

many of the Pliocene localities from sou them California to Cerros Island, 

off lower California.

FIG-. 2. Callista (Amiantis) callosa Conrad. U.S.N.M. 164953. Imperfect left valve; 

altitude 50 mm. Lower Pliocene (Fernando formation), Elsmere Canyon, near Newhall, Los Angeles County. Base evenly rounded in perfect 

specimens. Common from Pliocene to Recent.

FIG. 3. Callista subdiaphana Carpenter. U.S.N.M. 164951. Imperfect right valve; 

longitude 41 mm. Same locality as fig. 2. Abundant in the Pliocene and 

also found in the Recent.

FIG. 4. Terebratalia smithi Arnold. U.S.N.M. 164977. Pedicle valve; longitude 42 

mm. Pliocene, Temescal Canyon, 3 miles north of Santa Monica, Los 

Angeles County. Known only from the Pliocene. A somewhat variable 

species.

FIG. 4a. Same specimen as fig. 4. Brachial valve.

FIG. 5. Terebratalia smithi Arnold. U.S.N.M. 164977. Pedicle valve; longitude 29 

mm. Same locality as fig. 4. More prominent ribbing than specimen 

shown in fig. 4.

FIG. 5a. Same specimen as fig. 5. Brachial valve.

FIG. 6. Terebratalia occidentalis Ball. U.S.N.M. 164996. Brachial valve; longitude 

40 mm. Same locality as fig. 4. This species is most variable, as is

evidenced by this and the following figures, which show a series collected at one locality. Found in the lower Pliocene (and possibly upper 

Miocene).

FlG. 7. Same species and locality as fig. 6. Pedicle valve; longitude 29 mm.

FIG. la. Same specimen as fig. 7. Brachial valve.

FIG. 8. Same species and locality as fig. 6. Pedicle valve; longitude 22 mm.

FIG. 8a. Same specimen as fig. 8. Brachial valve.

FIG. 9. Same species and locality as fig. 6. Pedicle valve of a less rugose variety; 

longitude 21 mm.

FIG. 9a. Same specimen as fig. 8. Brachial valve.

250
U. S. GEOLOGICAL SURVEY

PLIOCENE BRACHIOPODA AND PELECYPODA.
PLATE XL.

PLIOCENE PELEGYPODA AND GASTEROPODA.

(Unless otherwise stated, all figures are natural size.)

FIG. 1. Mya truncata Linne. U.S.N.M. 164950. Left valve; longitude 46 mm. 

Pliocene (Fernando formation), Elsmere Canyon, near Newhall, Los 

Angeles County. Found also in the Recent fauna of the Arctic regions.

FIG. 2. Trochita fdosa Gabb. U.S.N.M. 164949. Slightly imperfect specimen 

viewed from above; maximum diameter 20 mm.; twice natural size. 

Same locality as fig. 1. Also found in the upper Miocene.

FIG. 2a. Same specimen as fig. 2. View from the side.

FIG. 3. Fissuridea murina Carpenter. U.S.N.M. 164945. Specimen viewed from 

above; longitude 14.5 mm.; twice natural size. Lower Pliocene, Third 

street tunnel, Los Angeles. Also found in the Pleistocene and Recent 

fauna of the coast.

FIG. 3a. Same specimen as fig. 3. View from the side.

FIG. 4. CanCellaria fernandoensis Arnold. U.S.N.M. 164956. Back view of imperfect 

specimen; altitude 17 mm.; twice natural size. Same locality as fig. 1. A 

similar or identical form was found in the Pliocene of the San Diego well.

FIG. 5. Tritonium sp. U.S.N.M. 164954. Back view of imperfect specimen; altitude 20 mm.; twice natural size. Same locality as fig. 1.

FIG. 6. Pisania fortis Carpenter var. angulata Arnold. U.S.N.M. 164959. Aperture 

view of imperfect young; altitude 30 mm. Same locality as fig. 1. A 

rather common species in the Pleistocene and Pliocene of central and 

southern California.

FIG. 7. Pisania fortis Carpenter var. angulata Arnold. U.S.N.M. 164958. Aperture 

view of imperfect adult; altitude 49 mm. Same locality as fig. 1.

FIG. 8. Cyprwa fernandoensis Arnold. U.S.N.M. 164961. Type. View from back; 

longitude 40 mm. So far known only from same locality as fig. 1,

FIG. 8a. Same specimen as fig. 8, Aperture view.

FIG. 9. Nassa hamlini Arnold. U.S.N.M- 164946. Type. Aperture view of imperfect specimen; longitude 15 mm. Same locality as fig. 3.

FIG. 10. Chrysodomus cf. arnoldi Rivers. U.S.N.M. 164962. Back view of imperfect

specimen. Same locality as fig. 1. Known also from the Pleistocene

of San Pedro, Los Angeles County. 

FIG. 11. Priene oregonensis Redfield var(?) anyelensis Arnold. U.S.N.M 164975. Back

view of imperfect and slightly contorted specimen; longitude 71 mm.

Same locality as fig. 3. Common in the lower Pliocene of the Pacific

coast. It is the precursor of the Recent Priene oregonensis Redfield. 

FIG. 12. Murex eldridgei Arnold. U.S.N.M 164955. Type. Back view; longitude

24 mm.; twice natural size. Known only from the same locality as fig.

1. Near the Recent M. incisa Broderip. 

FIG. 13. Pecten (Chlamys} hastatus Sowerby var. slrategus Ball. Collection of Delos

Arnold. Left valve; altitude 36 mm. Pliocene, Santa Barbara.

Also found in the Pliocene of southern California. 

FIG. 14. Pecten (Chlamys} bellilamellatus Arnold. Type. Right valve; altitude 18

mm. Pliocene, Pacific Beach, San Diego. Known only from this

horizon at this locality. 

252
U. S. GEOLOGICAL SURVE iULLETIN NO. 309 PL. XL

11

PLIOCENE PELECYPODA AND GASTEROPODA.
PLATE XLI.

TERTIARY TURRITELLAS.

(All figures natural size.)

FIG. 1. Turritella pachecoensis Stanton. U.S.N.M. 165002. Back view of imperfect 

specimen; altitude 59 mm. Eocene, Rock Creek, Los Angeles County. 

This species is supposed to be characteristic of the Martinez formation 

(lower Eocene.)

FIG. 2. Turritella uvasana Conrad. U.S.N.M. 164974. Wax cast, back view; altitude 

41 mm. Sespe Canyon, Ventura County. Supposed to be characteristic of the Tejon formation (middle Eocene).

FIG. 3. Turritella uvasana Conrad. U.S.N.M. 165004. Back view of imperfect specimen; altitude 44 mm. Eocene, Rose Canyon, San Diego County.

FIG. 4. Turtriella ineziana Conrad (-\~T. hoffmanni Gabb). U.S.N.M. 164964. Lower 

Miocene, supposed equivalent of the Fourfork formation, Chaffee Canyon, southwest of Pirn, Ventura County. Supposed to be characteristic 

of the lower Miocene; found from San Mateo to San Diego counties.

FIG. 5. Turritella ineziana Conrad. U.S.N.M. 164969. Back view of imperfect specimen; altitude 36 mm. Tar Creek, north of Fillmore, Ventura County. 

Common in the Vaquers formation, but- good specimens are hard to 

obtain.

FIG. 6. Turritella ineziana Conrad var. sespeensis Arnold. U.S.N.M. 164970. Type. 

Aperture view of imperfect specimen; altitude 34 mm. Same locality 

as fig. 5.

FIG. 7. Turritella ocoyana Conrad. U.S.N.M, 164990. Back view of imperfect large 

specimen; altitude 60 mm. Topanga Canyon, 3 miles south of Calabasas, 

Los Angeles County, Supposed to be characteristic of the lower Miocene. 

Common in central and southern California.

FIG. 8. Same species and locality as fig. 7; altitude 58 mm.

FIG. 9. Same species and locality as fig. 7; altitude 32 mm.; upper whorls.

FIG. 10, Turritella variata Conrad, U.S.N.M. 164991. Back view of imperfect specimen; altitude 34 mm. Same locality as fig. 7. Supposed to be characteristic of the lower Miocene; so far known only in Fresno County and 

south.

FIG. 11. Same species and locality as fig. 10. Slender variety; altitude 59 mm.

FIG. 12. Same species and locality as fig. 10. Broad variety; altitude 43 mm.

FIG. 13. Tunitella cooperi Carpenter (var.?) fernandoensis Arnold. U.S.N.M. 164957. 

Type. Aperture view of imperfect specimen; altitude 31 mm. Lower 

Pliocene, Fernando formation, Elsmere Canyon, near Newhall, Los 

Angeles County. A common form in the lower Pliocene of southern 

California.

FIG. 14. Turritella cooperi Carpenter. Collection of Delos Arnold. Aperture view 

of typical form. Lower Pleistocene, lower San Pedro formation, Deadman Island, San Pedro, Los Angeles County. Common in the Pliocene 

and lower Pleistocene from Ventura County southward.

FIG. 15. Turritella jewetti Carpenter. Collection of Delos Arnold. Typical form, 

aperture view; altitude 70 mm. Same locality and horizon as fig. 14; 

geologic and geographic range also about the same. 

254
U. S. GEOLOGICAL SURVEY BULLETIN NO. 309 PL. XU

10

TERTIARY TURRITELLAS.

INDEX.

Figures in italic denote illustrations of fossils.

A. Page.

Acknowledgments to those assisting....... 1,

102,138,203 

Acmtca pelta Eschscholtz.................. 27

sp....................................... 17

Actseon (Kictaxis) punctoccelata Carpenter. 27 

Adams Canyon, fossils near ................ 20

oil wells in............................ 4,42,45

oil of, analyses of............. 209,211,212

rocks in................................. 43,49

Agasoma barkerianum Cooper .............. 147

kernianura Cooper...................... 147

Aliso Canyon, oil wells in.............. 4,42, 45, 49

Amau ropsis alveatus Conrad..............; £84

Amiantis callosa Conrad.................. 25, 250

Arnusium lompocensis Arnold.............. 230

Analyses of oil............................ 209-217

methods of........................... 205-208

Anatina sp................................. 11

Angulus biutoni Dall....................... 27'

Anomia lampe Cray........................ 27

Antisell, Thomas, explorations of........ 138,139

on bituminous effusions................ 140

Area........................................ 247

camuloensis Osmont.................. 24, 146

labiata Sowerby........................ 26

multicostata Sowerby............ 107,152, 248

montereyana Osmont.................. 140

trilineata Conrad.................. 25,107, ?48

Arnold, Ralph, bibliography compiled by. 199-202 

fossils determined by.......... 12,14,17,25,26

on fossils of oil-bearing formations... 219-254 

on Los Angeles oil field............... 138-198

on physical and chemical properties of

southern California oils....... 203-218

Asphaltum, description of................ 139-141

Astarte sp.................................. 152

Astrodapsis whitneyi Conrad.............. 26

Astyris gausapata Could.................. 27,107

gausapata var. carinata Hinds......... 27

richthofeni Gabb....................... 26

B.

Balanus concavus Bronn............... 13,27, SS6

sp....................................... 14

Baptist College area, oil wells in, geology

of.........................*... 175-178

oil wells in, records of................ 177,178

Bard Oil and Asphalt Co., wells of......... 46

Bardsdale Crude Oil Co., wells of........ 10,78,79

Bardsdale-oil field, gas in................... 79

geology and structure of............... 70-79

location of.............................. 76

Oil wells of.............................. 79-80

oil of, analyses of..... 209,211,212.214-215

Page. 

Barlow's ranch, fossils from................ 27

Basalt, occurrence and description of...... 150

Basement rocks, character and distribution

of............................... 5

oil in.................................... 5

Bibliography of southern California oils.. 199-202 

Big Sespe Canyon, location of.............. . 4

See also Sespe oil fields. 

Bison sp.................................... 154

Bittium asperum Gabb................. 26,27,153

sp....................................... 147

Bitumen, description of.............. 139,140-141

Blake, W. P., explorations of.............. 138

^ on oil................................... 139

Brea, occurrence and description of........ 134,

139-141,154-155,157,187,194 

Brea Canyon field, geology of............ 120-121

location of.............................. 120

oil wells of..................-...'.. 123-125,133

oil of, analyses of......... 210,212,213-215

structure of........................... 121-123

tankage in............................... 134

view of................................. 120

Brea Canyon Oil Co., wells of............ 123-124

wells of, oil of, analyses of........ 210,212,213

Brea Eidge, rocks on..................... 106,125

Brush Mountain, rocks of.................. 34

structure at............................ 34

Buccinum sp............................... 152

Buckhorn Oil and Transportation Co., wells

of............................... 69

wells of, oil of, analyses of........ 209,211,212

Bulla punctulata A. Adams................ 107

Bulla wells, rocks near..................... 113

Bulloid sp.................................. 24

Burrows & Sons, oil wells of, oil of, analyses

of......................... 209,211,212

C.

Cadulus fusiformis Sharp and Pilsbry...... 27

Cahucnga Pass, rocks at and near.......... 350

Calabasas, fossils near...................... 147

California, index map of southern part of.. 2

oil of. See Oil. 

California Oil Co., well of................. .'. 98

Calliostoma costatum Martyn............ 107,153

sp...................................... 26,147

Callista (Amiantis) callosa Conrad......... 250

diabloensis Anderson.................. 147

subdiaphana Carpenter............. 24,25, 860

Camulos, fossils near....................... 24

Cancellaria condoni Anderson............ 147, 286

fernandoensis Arnold.................. 25, 252

tritonidea Gabb....................... 27,153

sp....................................... 24,107

257
258 INDEX.

Page. 

Canis indiancnsis............................ 154

sp....................................... 154

Carcharodon rectus Agassiz ................ 153

Cardium brewerii Gabb... .................. $24

cooperi Gabb........................... 882

corbis Conrad.......................... 26,107

procerum Sowerby...................... 26

linteum Conrad......................... 11

quadrigenarium Conrad var. fernandoensis Arnold............ 25,27,107, 848

sp................................... 17,24,147

Ctistac Creek, character of.................. 3

Central field, development of......... 158-159,172

geology oC............................ 165-170

location of:............................. 165

oil wells of........................ 167-169,172

oil of, analyses of.............. 210.211,213

records of......................... 168,169

section across, figure showing.......... 171

structure of........................... 170-171

topography of.......................... 165

view of..............;................... 168

Central Oil Co., pipe line of................. 135

wells of................................. 101

oil of, analysis of............. 210,212,213

view of, Murphy wells and.......... 112

Cerithidea californica Haldeman............ 153

Cerithium topaiigensis Arnold............ 147, 886

Chaffec Canyon, fossils from................ 17

rocks of................................. 80

Chaffee syncline, description of............. 80-81

Chama exogyra Conrad..................... 153

Chandler wells, location of.................. 114

Chino field, location of.................:.... 132

oil in...............................\. 110,132

Chino Oil Co., wells of...................... . 132

Chione fluctifraga Sowerby........:........ 107

mathewsoni Gabb...................... 26

succincta Valenciennes.................. 27

temblorensis Anderson............ 14,147,235

whitneyi Gabb.......................... 26

sp.............................'......... 14,146

Chlamys bcllilamellatus Arnold .. '.......... 252

calkinsi Arnold......................... 884

hastatus Sowerby var. strategus Dall..- 252 

latiauritus Conrad...................... 244

opuntia Dall............................ 244

parmeleei Dall.......................... 244

sespeensis Arnold..................... 834, $38

wattsii Arnold.......................... 848

Chlorostoma (Omphalius) dalli Arnold..... 147

dalli var. inornatus Arnold............. 226

var. subnodosus Arnold............ 886

funebrale A. Adams.................... 27

sp....................................... 24

Chorus belcheri Tlinds...................... 26,27

Chrysodomus arnoldi Rivers.............. 25, 252

sp....................................... 24

Clampitt, E. A., oil well of, oil of, analysis

Of......................... 210,211,213

Clathurella conradiana Gabb............... 153

Clidiophorapunctata Conrad............... 26

Cold water anticline, location of.......... 31,51,54

oil in.................................... 33,54

rocks in................................ 7,8,55

Colegrove, brea near........................ 154

oil field near............................ 158

wells of, geology of............... 182-184

records of..................... 183-184

Columbella (Astyris/gausapata Gould..... 27

var. carinata Hinds...................... 27

Columbia Oil and Producing Co., wells of.. 30.128

wells of, oil of, analyses of.......: 210,212,213

Columnar section, figure shoving........... 144

Consolidated Crude Oil Co., well of, oil of,

analysis of................ 210,211,213

Conus californicus Hinds.................. 24,107

sp....................................... 24

Cooper, H. N., analyses of................ 209-213

on methods of analyses of oil......... 205-208

Cooper, ,T. G., fossils determined by.... 11,26,152

Corbula luteola Carpenter.................. 153

sp....................................... 11,24

Correlations, table of............'........... 143

Coyote Hills, rocks in..................... 106,109

Coyote Hills anticline, description of....... 109

Cracks, joint, occurrence of................. 157

Crepidula adunca Sowerby................. 27

princeps Conrad....................... 26.153

rugosa Nuttall......................... 27,107

Crown King.well, location of............... 75

Cryptoyma californica Conrad....... 25,26,27,153

Crystalline schist, oil in................... 100-101

Cylichna alba Brown....................... 27

costata Gabb........................... 224

sp....................................... 147

Cyprfea fernandoensis Arnold.............. 8S8

D.

Davis and TIarrison, oil wells of, oil of,

analyses of ............... 210,211,213

Dentalium cooperi Gabb..................... 11

hexagonum Sowerby.................... 27

neohexagonum Sharp and Pilsbry ..... 107

semipolitum Broderip.................. 26

sp...................................... 14,107

Devils Gate, oil wells near.................. 54-55

Dewitt Canyon, oil wells in................. 4,95

Diabase, occurrence of...................... 106

Diplodonta orbella Gould................... 153

Dolichotoma carpenteriana Gabb........... 25

keepi Arnold ......................... 147, 238

Dohax l-.evigata Dcshayes.................. 27

Dosinia ponderosa Gray............... 24,147,888

sp....................................... 17

Drillia hemphilli Stearns.................... 27

inermis Hinds........................... 27

inermis var. penicillata Carpenter...... 27

sp................................. 147,153, 888

E.

East Canyon, oil wells in..............^.... 96

Eastern fi|ld, development of......... 159,164-165

geology of............................. 160-162

location of.............................. 160

. oil wellsof.................... 160-162,164-165

oil of, analyses of............. 210,211,213

records of......................'..... 162

structure of........................... 163-164

topography of.......................... 160

view of.................................. 168
INDEX. 259

Page.

Echinarachnius excentricus EschscholU. 24,26,27 

Echinoiclea. ............................... 831,883

Edgemont, rocks near.................... 145,146

Eldridge, G. H:, fossils collected by......... 26

on Puente Hills oil district............ 102-137

on Santa Clara Valley, oil district....... 1-101

work and death of............. xi, 138,141-142

Elephas..................................... 154

Elgin's ranch, fossils near.................j 17

Elsmere anticline, description of...........'. 97

oil in.................................... 98

Elsmere Canyon, fossils from............... 25

oil wells in.............................. 99

oil of, analyses of............. 209-211,213

Elsmere oil field, geology and structure of.. 97-98 

location of.............................. 4,96

wells of............................ 98-101

oil of, analyses of............. 214-215

view of.......................... 48

Elsmere Ridge, oil wells on ................. 99

view of...................:.............. 48

Elysian Park anticline, description of. 155-156,103 

Oil in...;.................'............. 150-157

Elysian Park hills, rocks of:...... 145-140,149,160

Empire Oil Co., wells of.................... 50

Enterprise well, data on.................... 97

Eocene fossils............................. m, 825

Equus...................................... 154

Eulimamicans Carpenter................... ' 27

hastata Sowcrby........................ 27

Eureka Canyon, oil field in, geology and

structure of..................... 80-86

oil field in, location of................... 80

wells of........................... 4,87-89

log of........................... 88

rocks in.................................81-83

Eureka Ridge, rocks of..................... 82

F.

Faults, occurrence of............... 29,30-31,34/35

See also particular districts.

Fernando formation, age and character of.. 22-23,

106,150-152 

correlation of........................ 22,23,24

distribution of. ... 22-23,43,49,52-53,66-08,75,

77-78,81-84,91-93,97,106,113,115,118,

120-123,125-131,144, 152, 173-174, 186

fossils of........................ 23-28,107,152

oil in.......... 45,86,98,99,110-113,115,126,193

Fernando Pass, fossils from................ 25

Fissuridcamurina Carpenter......... 107.152,252

Foot-of-the-Hill wells, data on............. 58-60

fossils near.............................. 13

map of................................... 59

Fortuna wells, data on..................... 69-70

map of.................................. 70-

view of.................................. 70

Fossils, character and distribution of. .... 11-17,

24-28,107,146-148,152-153,219-220

plates showing........................ 223-255

Fourfork Creek, oil wells on............. 12,00-61

oil wells on, map of............. ; ....... 60

rocks on................................. 13

Fourfork wells, oil of, analyses of......... 216-217

Freeman and Nelson, oil wells of.......... 98,100

Page.

Fryers Peak, section through, figure showing............................ 92

Fuel, use of oil for........................ 135,204

Fullerton Oil Co., wells of................... 128

Fusus barbarensis Trask. .........'......... 107

rcmondii Gabb.......................... 224

rugosus T rask........................... 24

sp...................................... 14,147

G.

Galerus inornatus Gabb.................... 20

Garberson Canyon, prospecting.in.......... 4

well in.................................. 79-80

Gas, analysis of............................. 204

occurrence of............................ 134

Gas making, use of oil for.................. 204

Gasteropoda................................. 107,

1d7 00T &OQ W^ 0^*7 0^7 QQQ 0/0 053 1:11 , KKU, KKi7, ZOiJj KOU t KOI , KOO, Kqv, Zdu

Geologic formations, correlation table of... 143 

descriptions of........... 4-29,103-107,143-155

Geologic maps. See Map, geologic. 

Geology. See Geologic formations; Structure: particular oil fields. 

Glycymeris barbarensis Conrad............ 153

intermedia Broderip.................... 26

veatchii Gabb var. major Stanton..... 884

sp....................................... 147

Goat Mountain, fossils from................ 26

Graham-Loftus Oil Co., wells of.......... 129,130

Granite, occurrence and description of..... 145

Granitic basement, character and distribution of......................... 5

oil in.................................... 5

Grimes Canyon, fossils near................ 17

oil wells in.....;........................ 4

rocks in................................. 78

H.

Hamlin, Homer, Fernando formation named

by.............................. 22

fossils determined by.................... 152

Happy Thought wells, data on............. 58

Hinnites giganteus Gray.............. 17,153, 8Sf!

Hipponyx cranioidcs Carpenter............. 20

Holser anticline, description of............. 67-68

oilin.................................... 68

Holser Canyon, oil wells in................. 75

Home Oil Co., wells of, oil of, analysis of... 210,

212,213 

rocks near............................ 112,113

Hoover street, Los Angeles, section along,

figure showing................. , 175

Hopper anticline, description of............ 64

oil in.:.................................. 67

Hopper Canyon, oil wells in................. 4,

34-35,65.68-70 

oil wells in, oil of, analyses of..... 20,211,212

rocks in..... -............................ 18,53

structure at..................:.......... 32

views in.................................. 2,70

Hopper-Piru oil fields, faults in............. 05

location of.............................. 4,64

oil wells of............................... 64-68

structure of............................. 68-75
260 INDEX.

I. Page.

Ivers anticline, location of.................. 51,56

oil wells on.............................. 51

Ivers wells, data on.......................... 55-56

location of, map showing............... 55

Kellia suborbicularis Montague............ 153

Kentuck wells, data on..................... 56-58

location of, map showing............... 57

oil of, analysis of..................... 216-217

structure at.......................... 33,56-57

LaBreaRancho Oil and Asphalt Co., well of,

oil of, analyses of......... 210.211,213

La Habra Canyon, oil field in, geology of.. 115 

oil field in, location of..'................. 115

structure of....................... 116-117

wells in............................. 117

oil of, analyses of......... 210,211,213

rocks in................................. 106

Lacuna compacta Carpenter................ 27

solidula Loven.......................... 26

sp....................................... 27

LEevicardium centifilosum Carpenter....... 26

Lake Shore avenue, Los -Angeles, section

along, figure showing........... 171

Langdell, Newmark and Roan, oil wells of. 40 

Laqueas californicus Koch.................. 153

Laughlins Hill, rocks of.................... 150

Leda gabbi Conrad......................... 11

taphria Dall................... 24,107, 146,248

sp.................................... 11,14,27

Lima hamlini Dall.......................... 152

Lion Canyon, bitumen in.................. 29

oil wells in..................:........... 40

rocks in............................ 9-10,28-29

Lion Canyon fault, location of............. 38

Lion Hill, faults at......................... 38

oil wells on.............................. 40

rocks in................................. 38

Literature on southern California oils.... 199-202

Lithophagus plumula Reeve................ 153

Little Sespe Creek, canyon of, oil wells in.. 4 

' canyon of, oil wells in, oil of, analyses

of........................ 209,211,212

fossils on and near,;.................... 13

oil wells on. ............................. 58

map showing....................... 59

rocks on................................ 13

See also Sespe oil fields. 

Littorina scuiulata Gould.................. 27

Los Angeles, fossils in and near...... 147,152-153

oil in and near. See Los Angeles oil district, 

rocks near.............................. 148

Los Angeles anticline, description of..... 184-185

Los Angeles district,brea in...... 139-141,153-154

columnar section in, figure showing..... 144

correlation in........................... j.43

explorations in....................... 138-142

folds and faults in.................... 155-157

future development o.f................ 196-197

geologic formations in................ 143-155

map showing....................... 144

Los Angeles district, lagoon in, view of... 188 

location of.............................. 142

map of................................. 158

Miocene sandstone in, view of.......... 166

oil of.................................. 203-217

analyses of....:................... 210-217

gravity of.......................... 203

oil derricks in, removal of............ 159-160

oil fields of............................ 156-157

descriptions of.................... 158-195

development of................... 158-1GO

location of.......................... 158

oil prospects in southwest and west of. 197 

oil wells of......... 162,167-169,174-184,187-193

location of, map showjng........... 158

Pliocene sandstone in, view of.......... 188

production of........................... 198

sections in, figures showing. ....'........ 171,

175,178,181,189 

storage in................................ 198

structure of........................... 155-157

sections of, plate showing.......... 162

topography of..'...................... 142-143

transportation of oil in................. 198

See also Central, Eastern, Western, and

Salt Lake fields. 

Los Angeles Pacific Rwy. Co., wells'of, oil of,

analyses of............... 209,211,212

Los Angeles Rwy. Co., well of, oil of, analyses of..................... 210,2if, 213

Los Angeles River, oil prospects east of.... 19G

Los Angeles wells. See Foot-of-the-Hill

wells. 

Lower Ojai Valley, section across, figure

showing......................... 9

See also Ojai Valley. 

Lunatia lewisii Gould....................... 24,26

Lyon, L. H., wells of....................... 71

Lyons anticline, description of............. 65-60

oil in.................................... 67

Lyropecten ashleyi Arnold................. 240

bowersi Arnold......................... 226

crassicardo Conrad..................... £34

estrellanus Conrad...................... 228

magnolia Conrad....................... 228

vaughani Arnold....................... 238

M.

Macintosh well, oil of, analyses of......... 216-217

McKittrick district, oil wells of............. 109

Macoma i ndentata Carpenter............... 25

inquinata Deshayes..................... 153

nasuta Conrad..................... 27,147,153

secta Conrad........................... 24

sp................................ 25,26,27,152

Macronmerriami Arnold................. 147,228

Mactra californica Conrad.................. 153

catillif ormis Conrad.................... 27

hemphilli Dall.......................... 25

Maltman well, oil of > analyses of.......... 216-217

Mangilia angulata Carpenter............... 27

sp......................... -. ............. .24

Manley (M.) & Co., oil well of, oil of, analy-'

sis of...................... 210,211,213

Map of Los Angeles district................ 158
INDEX. 261

Map of Puente Hills district ............... 110

of Santa Clara Valley................... 30

Map, geologic, of Los Angeles district...... 144

of Puente Hills......................... 102

of Santa Clara Valley................ Pocket.

Map, index, showing location of oil fields... 2 

Margarita sp................................ 26

Matilija Creek, hot springs on.............. 3

Menges Oil Co., wells of.................. 123,124

Meretrix californiana Conrad............... 11

hornii Gabb............................. 828

Merriam, J. C., fossils determined by....... 24

on Fernando fossils..................... 23

on Los Angeles brea fossils............. 154

Metis alta Conrad...................... 24,26,107

Miocene basalt, occurrence and description

of............................... 150

Miocene fossils........ 827, 229,231,283,235,837,239

Miocene sandstone, views of................ 166

Mitra maura Swainson.................... 26,153

Modelo anticline, description of....... 64-65,71-72

location of.............................. 32,34

oil in........................... 34-35,65,67,69

Modelo Canyon, bitumen in................ 20

oil wells in...................... 4,18,65,71-74

oil of, analyses of......... 209,211,213-215

records of........................... 73

view in.............................. 70

rocks in.............................. 18,64-65

Modelo formation, bitumen in.............. 20

burning of.............................. 22

character of........................... 17,20-21

correlation of........................ 18,20-22

distribution of......................... 17-21,

37,42-43,47,49,53,62-63,64-67,77,81-86 

faults in................................ 37,44

fossils in................................ 20,37

Monterey formation and, relations of... 17. 

Oil in......... 18,20,34,40,41,45-46,69,71-74,86

subdivisions of, description of.......... 18-20

Vaqueros formation and, relations of. 13,19-20 

Modelo Oil Co., wells of.................. 34,72-74

, wells of, logs of......................... 73

oil of, analyses of............. 209,211,213

view of............................. 70

Modelo syncline, location of................ 32

Modiolus fornicatusCarpenter. . s .......... .27

Modiolus ornatus Gabb.................... 222

rectus Conrad...................... 25,26,107

. sp....................................... 12,27

Monia macroschisma Ball.................. 25

Monoceros engonatum Conrad............ 27

lugubre Sowcrby....................... 26

Monterey formation, correlation of Modelo

and.......................... 18,20-21

correlation of Puente and............... 105

fossils in................................ 21

Mono (Sconsia) tuberculatus Gabb........ 884

Murex eldridgei Arnold.................... 25, 258

monoceros Sowerby.................... 26

Murphy Oil Co., pipe line of................. 135

wells of................................. Ill

oil of, analysis of................... 204

view of Central wells and........... 112

Mya truncata IA.tm&....................... 25,858

Bull. 309 07 18

Page. 

Mylodon sp................................ 154

MytitTis mathewsonii Gabb var. expansus

Arnold................. 14,, 17,147, 238

N.

Nassa californiana Conrad.......... 24,26,27,153

cretacea Gabb.......................... 11

fossata Gould..:.................. 27,107.153

hamlini Arnold...................... 152, 858

mendica Gould........................ 27,153

var. cooperi Forbes................ 26

perpinguis Hinds............... 26,27,107,153

sp....................................... 14

Natica sp................................... 147

Neara dolabriforrnis 'Gabb................. 11

Neptunea altispira Gabb..........:........ 26

humerosa Gabb........................ 25

Nettleton and Kellerman, oil wells of....... 98,99

Neverita callosa Gabb.................... 147, 234

 recluziana Petit......... 25,28,107,152,153, 248

var. alta Ball....................... 28

sp...................................... 14,147

New Camulos well, location of.............. 75

New Century Oil Co., oil wells of.......... 98,100

New England Oil Co., wells of.............. 117

rocks near.............................. 116

Newhall, rocks near........................ 22

wells near, location of, map showing.... 100

view of.......................... '... 48

Newhall district, subdivisions of........... 90

Newhall well, data on...................... 90

Nigger anticline, location of................ 35

oil wells on............................. . 35

Nigger Canyon, oil wells in.................. 4,71

Nordhoff, location of....................... 36

oil wells near........................... 39,40

North Whittier Oil Co., wells of.......... 114-115

Nucula castrensis Hinds.................... 24

solitaria Gabb.......................... 11

truncata Gabb......................... 11

sp....................................... 24

0.

Oak Ridge, elevation of.................... 3

fossils on............................... 17

oil wells on............................. 4

rocks of............... 10,15,20-22,53,78-79,85

view of................................ 46

Oak Ridge-South Mountain anticline, description of..................... 77-79

oil wells on............................. 79-80

Oat Mountain, rocks on.................... 13,53

structure of............................. 31,63

Ocinebra lurida Middendorf................ 153

topangensis Arnold................... 147, 832

Odostomia gouldii Carpenter............... 28

nuciformis var. avellana Carpenter..... 28

tenuia Carpenter........................ 28

Ohio, oil of, composition of................. 204

Oil, associates of........................... 134

analyses of........................... 209-217

methods of....................... 205-208

character of....................... 133,203-217

See also particular wells.
262 INDEX.

Oil, color of................................._ 203

composition of.......................... 204

geologic relations of.......... 109-110,132-133

gravity of.............................. 203

occurrence of, north of Santa Clara River 32-35 

prices of...'............................. 136

production of......................... 136,198

products of.-............................ 205

storage and transportation of.... 134-135,198

utilization of...................... 135-130,204

Oil companies, list of..................... 137,195

Oil fields, descriptions of... 36-101,110-132,158-198 

location of....................... 4,36,110,158

map showing....................... 2

Oil refineries, list of........................ 218

productsof:...............^........... 205,218

Oil wells, location of, maps showing... 36,110,158 

yield of............................... 133-134

Ojai Oil Co., wells-of..........:..........".. 48

Ojai Valley, description of.................. 3

faults in........................ 3,30-31,36-39

fossils in............................. 14,21,37

oil fields in, description of.............. 36-42

location of.......................... 4,36

.oil of, analyses of..... 209,211,212,214-215

rocks in ........................ 9,13-15,20,29

structure of....................... 30-31,36-39

See also Upper Ojai Valley; Lower Ojai 

Valley.

Olinda field, fault in........................ 126

geology of............................ 104,125

section showing.................... 130

location of.............................. 125

oil wells in........ I................ 131-133,203

oil of; analyses of......... 210,212,213-215

structure in........................... 126-131

plate showing.......................... 130

tankage in.............................. 134

view of................................. 124

Oliv.ella biplicata Sowerby................. 28

intorta Carpenter................... 25,26,28

pedroana Conrad....................... 28

sp........ ............................... 27

Omphalius dalli var. inornatus Arnold..... 226 

dalli var. subnodosus Arnold........... 886

Ostrea eldridgei Arnold................... 17, 230

idriaensis Gabb......................... 12

titan Conrad.................. 17,147, 226,236

veatchii Gabb................. 24,107,152,153

sp ........................................ 14

Oxyrhina plana Agassiz.............:...... 153

tumula Agassiz......................... 153

P. 

Pachypoma sp.............................. 24

Pacific Coast Oil Co., wells of......... 94,96,98,99

wells of, oil of, analyses of........ 209-211,213

Paleontology. See Fossils.

Panopea generosa Gould............ 17,25,26,146

Park Crude Oil Co., well of, analysis of..... 210,

211,213 

Parke, J. G., explorations by............... 139

Pasadena, fossils from...................... 146

Patinopectencaurinus Gould............... &44

healeyi Arnold.......................... 240

Page.

Pearl Oil Co., wells of...................... 98-99°

wells of, oil of, analysis of........ 209,211,213

Pecten................................ 241,243,245

- (Lyropecten) ashleyi Arnold......... 152, 240

auburyi Arnold ...................... 153, 242

bellus Conrad.......................... 24, 242

(Lyropecten) bowersi Arnold........ 147, 226

(Patinopecten) caurinus Gould........ 25,#44

(Chlamys) calkinsi Arnold ............ 11, 224

(Plagioctenium) cerrosensis Gabb..... 24,242

(Plagioctenium) circularis Sowerby.... 242

(Lyrop'ecten) crassicardo Conrad.. 14,147, #34 

(Lyropecten) estrellanus Conrad....... 228

var. catalinse Arnold ............... 25

(Hinnites) giganteus Gray............ 17,236

(Chlamys) hastatus Sowerby var. strategus Dall........................ 252

(Patinopecten) healeyi Arnold.... 25,153,240

(Propeamusium) interradiatus Gabb.. 11,224 

(Chlamys) latiauritus Conrad........ 152,244

var. monotimeris Conrad........... 28

(Amusium) lompocensis Arnold ...... 14,230

' (Lyropecten) magnolia Conrad........ 14, 228

martinezensis Gabb.................... 11

merriami Arnold...................... 24,244

miguelensis Arnold..................... 147

(Chlamys) opuntia Dall.............. 152,044

(Chlamys) parmeleei Dall............. 25, 244

(Pseudamusium) peckhami Gabb.. 21,105,234 

(Pseudamusium) pedroanus Trask..... 21,

105,147,153,244

'(Chlamys) sespeensis Arnold... 12,13,234, 238 

var. hydei Arnold.................. 13,17

stearnsii Dall............'..... 152,153, 242,£44

(Lyropecten) vaughani Arnold........ 14,23S

vogdesi Arnold......................... 242

(Chlamys) wattsii Arnold.............. 242

Pelecypoda.................. 107,147,223,225,227,

229,231,233,235, 237, 239,249,251,253

Pennsylvania, oil of, composition of........ 204

Periplomadiscus Stearns................... 153

Petricola carditoides Conrad............... 153

Petroleum. See Oil.

Phacoides acutilineatus Conrad........ 25,107,146*

californicus Conrad................... 107,153

childreni................................ 147

nuttallii Conrad........................ 107

 richthofeni Gabb................. 107,147,236

sp.................................... 14,17,24

Pholadidea penita Conrad.................. 27

Pico anticline, description of ............... 90-92

location of.............................. 36

oil wells in.............................. 92,95

view of................................. 90

Pico Canyon, oil wells in................. 4,94-95

oil wells in, oil of, character of.......... 4

oil of, analyses of................... 209,

211,213,216-217 

overturn in, view of.................... 90

rocks' in................................. 17

views in................................ 90

Pico oil field, geology and structure in...... 90-94

. location of.............................. 90

subdivisions of......................... 93-94
INDEX. 263

Page 

Pico oil field, wells in................... 94-96,203

Pine Mountain, elevation of................ 2

Pioneer well, data on....................... 100

Pipe lines, length and distribution of..... 135,198

Pirieranch, oil wells at..................... 39-40

Piru Creek, canyon of, Fernando formation

at............................... 23

canyon of, oil wells in................ 4,74-75

structure in......................... 32

See also Hopper-Piru fields, 

character of............................ 3

fossils on............................... 24

rocks on.............................. 1. 23

structure east of........................ 67-68

Piru Oil and Land Co., .wells of............. #4-75

Piru River, view of......................... 2

Pisania fortis Carpenter var. angulata Arnold ........................... 25,25*

Placerita Canyon, oil wells in ...... 4,100-101,203

oil wells in, location of, map showing... 100 

oil of, analysis of................. 214-215

Placunanomia sp.......................... 13,153

Plagioctenium cerrosensis Gabb........ .... %4%

circularis Sowerby...................... 2-J2

Platyodon cancellatus Conrad.............. 153

Pleistocene deposits, distribution and description of.................... 28-29,

43,91,98,107,153-155,173,174,186

Pleurotoma (Dolichotoma) keepi Arnold... 238

sp........................................ 152

Pliocene fossils....... m, 84S, 2^5, tip, 249, 2dl, 853

Pliocene sandstone, view of................ 188

Pole Canyon oil field, geology and structure

of.............................. 62-63

location of.............................. 62

Priene oregonensis Redfield var. arigelensis

Arnold.................. 24,25,107,555

Propeamusium interradiatus Gabb........ 284

Proudfit and Parker, oil well of, oil of, analyses of....................... 210,211,213

Prutzman, P. W., analyses by........... 2-14-215

on California oils....................... 142

Psephis lordi Carpenter.................... 27

tantilla Gould.......................... 26

Pseudamusiuni peckhami Gabb............ 234

pedroanus Trask....................... 244

Puento fault, location and description of. 108-109,

111-113,116,119

Puente field, geology of................... 117-118

location of...........:.................. 117

oil wells of........................ 119,133,203

oil of, analyses of......... 210,212,213-217

structure of........................... 118-119

tankage in.............................. 134

Puente formation, character of.......... 103-105,

145-146,148-149 

correlation of........................... 105

distribution of....................... 103-105,

112-113,115,117-118,121,125-131,

144,145-146,148-150,160, 173,186

fossils in.......................... 104,146-148

oil in...... 110,114,119,132-133,149-150,156,187

subdivisions of....................'..... 103

Puente Hills, altitudes in................... 103

area in......^........................... 134

Page. 

Puente Hills, correlations in ............... 143

development of....................... 132-133

gas in................................... 134

geology of..:..................... 103-107,143

map showing....................... 102

location of....:......................... 102

map of.................................. 110

oil of.......................... 133-137,203-217

analyses of....................... 209-217

gravity of........................ *133,203

prices of............................ 136

production of....................... 136

storage and transportation of.... 134-135

utilization of..................... 135-136

oil-bearing strata of.................. 109-110

oil companies of, list of................... 137

oil wells of.... 113-115,117,119,123-125,131-134

location of, map showing........... 110

yield of........................... 133-134

See also particular wells. 

oil fields of, descriptions of........... 110-132

structure of........................... 108-109

sections of, plate showing.......... 108

topography of.......................... 103

Puente Oil Co., pipeline of................. 135

wells of ............................. 119,132

oil of, analyses of............. 210,212,213

Pumping plant, view of.................... 120

Purpura edmondi Arnold................ 147, 226

R.

Ramona Canyon, oil well in................ 68

Ramona Oil Co., well of.................... 68,75

Raphetto Hills, oil prospects in............ 196

rocks of............................... 152,196

Reasoner syncline, description of........... 07

Red beds, distribution of................. 8-10,47

faults in................................ 38

fossils in................................ 11

gas in................................... 39

occurrence of, in Sespe formation........ 8-10

oil wells in.................. 10,34,39,48,55,59

structure of, maps showing............ 55,57

Vaqueros shale and, relations of....... 11

Refineries. Sec Oil refineries.

Rice, W. P., oil wells of..................... 96

Rice Canyon, oil wells in................... 4,96

Rictaxis punctocoelata Carpenter.......... 27

Ridge Crest, oil well near................... 99

Road dressing, oi 1 used for............... 135-136

Rocks. See Geologic formation.

Russell Company, wells of.................. 54

S.

Salt Lake Company, oil wells of............ 159

Salt Lake field, brca in..................... 187

development of....................... 159,195

geology of............................ 186-193

location of............................ 158,186

oil sands of........................... 186-193

section of, figure showing........... 189

oil wells in........................ 187-193,195

oil of, analysis of.............. 210,211,213

records of......................... 190-193

section in, figure showing............... 189
264 INDEX.

Page.

Salt Lake field, structure in.............. 193-195

view of................................. 168

Salt Lake flexure, description of.......... 193-195

section through, figure showing........ 189

Salt Lake Oil Co., well of, oil of, analysis of.. 210,

211,213

Salt Marsh Canyon, oil wells in ....... 4,42,45-46

oil wells in, oil of, analysis of..... 209,211,212

San Cayetano fault, location of............. 30-31,

44,46,47,49,52 

oil wells along.......................... 49

San Cayetano Mountain, fault center at.. 30-31,44 

oil field near. See Santa Paula Ridge, 

rocks at................................ 23,48

See also Santa Paula Canyon.

San Cayetano wells, data on........... 68-69,203

location of.............................. 4,68

San Fernando field, well in, oil of, analyses

of......................... 209,211,213

San Gabriel Range, elevation of............ 3

oil wells on.......................... 96,98,99

rocks in................................. 35,97

structure of............................. 35-36

topography of........................... 2-3t

San Juan Hill, altitude of.................. 103

Sansinena wells, description of............. 117

Santa Ana Oil Co., oil wells of.............. 98

oil wells of, oil of, analyses of..... 209,211,213

Santa Barbara Forest Reserve, location of. 2

Santa Clara River, course of............... 1

oil fields north of....................... 36-75

oilfields south of...............:...... 76-101

red beds south of....................... 10

structure north of...................... 30-35

structure south of...................... 35-36

tributaries of........................... 3

valley of, oil field of. See Santa Clara

oilfield. . 

Vaqueros formation south of.......... 15-17

Santa Clara Valley oil field, correlations in. 21-22,

143 

fault in.................................. 29

geology of........................... 4-29,143

map showing..................... Pocket

map of.................................. 36

oilof........................:......... 203-217

analyses of....................... 209-217

gravity of.......................... 203

oil fields of........................... 4,36-101

oil wells of................. 39-42,45-46,48,50,

54-62,68-75,79-80,86-89,94-96,98-101 

location of, map showing........... 36

structure of............................. 29-36

sections of, plates showing......... 28,30

/ topography of............... '........... 1-4

Santa Fe Oil Co., wells of............. 128,129,130

wells of, oil of, analyses of........ 210,212,213

Santa Felicia Creek, fossils on.............. 24

Santa Monica Mountains, rocks on....... 145,146

Santa Paula Canyon, fault center at.. 38,44J 48,50 

fault center at. See also San Cayetano

Mountain, 

oil wells in, oil of, analyses of.......... 214-215

rocks in.................J............... 47

view of..........................'....... 48

Page. 

3

26 

49 

42

Santa Paula Creek, character of.........

fossils from..........................

rocks on.............................

Santa Paula Oil Co., oil wells of.........

Santa Paula Ridge, oil field south of, faults

in................................... 50

oil field south of, geology and structure

of................................ 49-50

oil wells of.............................. 50

rocks of................................. 48

Santa Susanna Mountains, oil wells in...... 4

rocks of........................ 15,20-22,43,92

view of................................. 46

Saugus, rocks near......................... 28,29

Sa^idomus aratus Gould................... 28

gibbosus Gabb......................... 153

gracilis Gould.......................... 27

Scala crebricostata Carpenter.............. 28

tincta Carpenter........................ 28

Schist, black, occurrence of........'......... 145

Schist,crystalline, oil in.................. 100-101

Sconsia tuberculatus Gabb................. 2%4

Scott and Loftus, oil well of................ 196

ScuteUa fairbanksi Merriam........ 13,17, 830,832

Semele decisa Conrad....................... 153

sp............ ........................... 26

Sespe Creek, canyon of, faulting in......... 52

canyon of, oil in........................ 33

oil weUs in.......................... 54-56

Pleistocene near.................... 28

section across, figure showing.:.... 8

character of............................ 3

region of................................ 2

structure in......................... 31

rocks on and near................... 28,30,52

Sespe formation, character of.............. 7-12

conglomerate in........................ 9

detail of, section showing............... 8

distribution of............... 7-12,51-52,63,78

faults in................................ 38

fossils in................................ 11

oil from............ 10,12,33,54,55,58,59,61,87

subdivisions of, description s of......... 8-12

Vaqueros shale and, relations of....... 11

Sespe oil field, location of................... 51

oil wells in.............................. 54-63

structure of............................. 51-53

view in................................. 2

Shields Canyon, oil well in.................. 80

prospecting in....'...................... 4

Shirley, I. W., oil well of, oil of, analysis of.. 210,

211,213 

Sigaretus perrini Arnold................. 147, 888

Siliq.uaedentula Gabb...................... 107

patula Dixon............................ 27

Siliquaria edentula Gabb................... 26

Silver Thread fault, location of............. 47,48

oil wells along.......................... 48

Silver Thread oil field, fossils in............ 11.

location of.............................. 4,46

oil wells in.............. v .............. 48

oil of, analyses of....'. 209,211,212,214-215

structure of............................ 46-48

Simi Valley, rocks in....................... 77

Sisar Creek, fossils from...... ............. 11
INDEX. 265

Sisar Creek, rocks on ...................... 29,47

Sisar Creek oil field. See Silver Thread oil

field. 

Smilodon sp................................ 154

Sobro Vista, Oil Co., oil wells of............. 41-42

Solen paralleius Gabb ...................... ,11

rosaceus Carpenter..................... 26

sicarius Could......................... 24,107

Sequel Canyon, rocks in.......... 104,125,127-128

South Mountain, elevation of.............. 3

rocks in.............................. 15,20,77

South Mountain-Oak Ridge anticline, description of..................... 76-78

oil wells on............................. 79-80

Southern Sulphur Mountain field. See

Sulphur Mountain. 

Spirocrypta pileum Gabb.................. 11

Spisula planulata Conrad.................. 26

Structure, account of............... 29-36,108-109

sections of, plates showing,. 28,30,108,130,162 

See also particular oil fields. 

Sulphur Canyon, fossils in.................. 21

Sulphur Mountain, altitude of.............. 3,42

faults at........................ 38r39,44-45,63

oil field on, description of............... 42-46

geology of.......................... 42-43

location of.......................... 4,42

oil wells in...................... 45-46,203

structure of......................... 44

oil wells on............................. 40

oil of, analyses of............. 209,211,212

rocks on....................... 20,38,42-43,47

Sulphur Mountain fault, location of........ 63

Sulphur Mountain Petroleum Co., well of.. 209,

211,212 

Sulphur Peak, rocks at..................... 54,55

Sunset Oil Co., wells of............... 34-35,65,69

Syncline, oil in.......................... 33,56-57

T.

Tankage, amount and distribution of.... 134,198

Tapes staleyi Gabb......................... 153

staminea Conrad....................... 27

tenerrima Carpenter.................... 25,28

Tapo anticline, description of.............. 84,91

location of............................ 36,82-83

oil wells in.............................. 89

Tapo Canyon, oil field in, geology and structure of.......................... 80-86

oil field in, location of.................. 80

wells of........................... 4,16,89

rocks in................................. 16

Tar Creek, canyon of, oil wells in......... 4,61-62

canyon of, oil wells in, oil of, analyses

of...........'.................. 216-217

fossils from........................:.... 12

rocks on and near....................... 13,18

Telegraph Canyon, rocks in................ 131

Tellina hoffrnaniana Gabb.................. 11

longa Gabb............................. n

parilis Gabb............................ 11

idse Dall............................. 25,26,153

Temple road. See Western avenue and 

Temple road.

Page. 

Terebra simplex Carpenter ................. 28

Terebratalia occidentalis Dall ............ 153, 850

smithi Arnold .......................... 260

Teredo sp.. ................................. 224

Tertiary fossils ............................. 255

Texas, oil of, composition of ................ 204

Thompson llidge, faults in ................. 37-38

rocks in................................. 37-38

Thompson Ridge fault, location of ......... 37

Thracia semiplanata Whiteaves ............ 11

sp. ...................................... 140

Timber Canyon, oil well in, oil of, analysis

of ......................... 209, 211, 212

Topatopa anticline, description of .......... 30

oil wells on ........................... 33, 34, 54

rocks of ................................. 33

view of ................................. 2

Topatopa formation, age of ................ 7

character of ............................ 5-6

distribution of .................. 7, 46-47, 49, 51

oilof......... ........................... 7,33

oil wells "in .............................. 54, 55

Topatopa Range, altitude of ............... 3

structure of ............................. 30

Topography, description of ................ 1-4

Tornatina culcitella Could ................. 28

harpa Dall. . ............................ 28

Torrey anticline, description of ............. 81-83

location of .............................. 36

Torrey Canyon, fossils from ................ 17

oil field in, geology and structure of . . ..- 80-86

location of .......................... 80

wells in. ............................ 86-87

oil of, analyses of. .... 209, 211, 213-215

rocks in .............................. 16, 81-83

Towsley Canyon, oil wells in ............... 4, 95

Tresus nuttalli Conrad ..................... 26, 27

Triton gibbosus Broderip .................. 26

Tritonium sp ........................... 14, 25, 252

Trochita costellata Conrad ........... 107, 148, 286

filosa Gabb ............................ 25,252

inornata Gabb. ......................... 148

sp........... ............................ 17

.Trophon multicostata Conrad. ............. 107

sp. .............................. 13, 14, 147, 148

Turbo topaugensis Arnold. .............. 148,228

Turbonilla laminata Carpenter ............. 28

sp. ................................... 11, 26, 28

Turritella.. . ................................ 254

cooperi Carpenter, var. fcrnandoensis

Arnold. .................. 25, 27, 28, 107, 864

hoff manni Gabb ........................ 864

ineziana Conrad .................... 14, 17, 254

var. sespeensis Arnold .....'......... 12, 13

jewetti Carpenter...................... 26,254

ocoyana Conrad ....................'.. 148, 254

pachecoensis Stanton ..................; 254

. uvasana Conrad ....................... 11, 264

variata Conrad................... 147,148,254

sp. .................................. 24

Union Consolidated Oil Co., wells of ........ 33, 54

Union Oil Co., tanks and pipe lines of. 134-135, 198
266 INDEX.

Page. 

Union Oil Co., wells of ...... .39,79,116,117,123,124

wells of, oil of, analyses of............ 209,212

rocks near.......................... 116

Upper Ojai Valley, oil wells in.............. 40,42

oil wells in, location of, map showing... 41 

rocks in................................. 29

view of................................. 46

V.

Vaqueros formation, age of................ 12

bitumen in.............................. 94

character of...........1................ 12-13

distribution of......................... 13-17,

37,62-63,64,66,78,81-86,91-93,97 

fossils in.......................... 12-13,14,17

Modelo formation and, relations of.. 13,19-20 

oil in.................. 34,61,68,88,89,93,95,98

overturn of, view of.................... 90

Sespe red beds and, relations of......... 11

Venericardia planicosta Lamarck......... 11, 2%%

ventricosa Gouid......... i............. 153

Ventura, fossils from near................... 27

Venus pertenuis Gabb...................... 147

temblorensis Anderson................. 23%

W.

Watts, W. L., analyses of...........:.... 216-217

fossils collected by...............'... 24,26,152

reports of, on California oils...... 139,141,158

reports of, on Los Angeles district.... '158-159

West Lake Oil Co., well of, oil of, analysis

of.................-------. 210,211,213

West Virginia, oil of, composition of....... 204

Westlake-Rommell Oil Co., well of, oil of,

analysis of................ 209,211,212

Western avenue and Temple road, Los Angeles, area one-fourth mile from, 

wells of, geology of............. 181

vicinity of, oil wells in, geology of.... 178-180

records of............................. 179-180

Western field, development of.............. 159

Page. 

Western field, geology of................. 173-184

. 'location of.... '. .................. -....... 172

oilwellsof............................ 174-184

oil of, analyses of............. 210,211,213

records of..................... 177-180,184

section in, figure showing...;......... 178,181

structure in........................... 184-186

subdivisions of....................... 174-175

topography of.......................... 172

Wheeler Canyon, oil wells in......... 4,42,45-46,49

oil wells in, oil of, analyses of..... 209,211,212

Whidden-Double Oil Co., oil wells of....... 40-41

oil wells of, oil of, analysis of..... 209,211,212

Whitney, J. D., explorations by.......... 138,140

on brea deposits....................... 140-141

Whittier field, gas well in................... 109

geology of.......:............ 104-105,110-112

location of.............................. 110

oil wells in........................ 111-115,133

oil of, analysis of................. 210,215

view of............................. 112

pumping plant in, view of.............. 120

structure of........................... 112-115

tankage in.../.......................... 134

Whittier-Fillmore Oil Co., well of, oil of,

analysis of................ 210,211,213

Wiley Canyon, fossils from................. 17

oil wells in.............................. 4,96

oil of, analyses of ............. 210,211,213

prospecting in.......................... 4

rocks in........................... 15-16,78,92

Y.

Yoldia arata Whiteaves.................... 11

cooperi Gabb........................... 28

nasuta Gabb........................... 11

scissurata Dall......................... 24

sp........................................ 27,147

Z.

Zenith Co., oil wells of.