LIBRARY
XJNffSnERSITY OF CALIFORNIA
DAVIS
MINERAL RESOURCES
OF
CALIFORNIA
BULLETIN 191
1966
California Division of Mines and Geology
Ferry Building, San Francisco, CA 94111
LIBRARY
UNIVERSITY OF CALIFORNIA
DAVIS
This volume, "Mineral Resources of California", is Port I of a larger
work. Mineral and Wafer Resources of California. It was prepared by
members of the staffs of the U.S. Geological Survey, the U.S. Bureau
of Mines, and the California Division of Mines and Geology, at the
request of Senator Thomas H. Kuchel. It is issued by the California
Division of Mines and Geology as number 191 in the Bulletin series.
Part II, a companion volume dealing with water, is not distributed
by the Divison of Mines and Geology.
STATE OF CALIFORNIA
Edmund G. Brown, Governor
THE RESOURCES AGENCY
Hugo Fisher, Adminisfrafor
DEPARTMENT OF CONSERVATION
DeWitt Nelson, Director
DIVISION OF MINES
AND
GEOLOGY
Ian Campbell, Sfote Geologisf
BULLETIN 191
Price $2.00
Author Index— Mineral Resources of California
AUTHOR INDEX
Page
Adams, J. W.
Rare Earths 350
Addicott, W. O.
See under RepenninR, C. A.
Albers, J. P.
Geomorphic Provinces 35
Mineral Resources — Introduction 77
Topographic and Geologic Maps-_ 21
Topography 23
Alfors, J. T.
Cobalt ^^ 139
Allison, Jil. C.
See under Peterson, G. L.
Aune, Q. A.
Antimony 81
Arsenic 85
Bismuth 102
Bailey, E. H.
See under Davis, F. F.
Bateman, P. C.
Geology of the Sierra Nevada _ 54
Bowen, O. E.
Limestone, Dolomite, and Lime
Products 221
Broderick, G. N.
See under Kinkel, Arthur R., Jr.
Burnett, J. L., and Weiler, C. T.
Shale, Expansible 37-1
Butler, A. P.
See under Walker, G. W.
Campbell, Ian
Tlie Mineral Industry of California 11
Chesterman, C. W.
Fluorspar 1G5
Pumice, Pumicite, Perlite, and A^ol-
canic Cinders 33G
Clark, W. B.
Gold 179
Platinum Group Metals _ __ 332
Cleveland, G. B.
Aluminum 71t
Diatomite 151
Davis, F. F., and Bailey, E. H.
Mercury 247
Davis, F. F., and Hewett, D. F.
Manganese _ __ 243
Dibblee, T. W., Jr.
Geology of the Transverse Ranges 6 0
Dil)blee, T. W., Jr., and Hewett, D. F.
Geology of the Mojave Desert Re-
gion __ G2
Durrell. Cordell
Quartz Crystal 344
Strontium 408
Edgerton, C. D., Jr.
Carbon Dioxide 119
Natural Gas Liquids 209
lOspenshade, G. H.
Kyanite, Andalusite, and Related
Minerals 212
lOvans, J. R.
Thorium 420
Fischer, R. P.
Vanadium _ 439
Gastil, R. G.
See under Peterson, G. L.
Gay, T. E.
See under Macdonald, G. A.
Goldman, H. B.
Sand and Gravel ^ 301
Sands, Specialty _ 369
Stone, Crushed and Broken 392
Stone, Dimension 400
Gower, H. D.
Phosphate 328
Gray, C. H., Jr.
Tin 422
Page
Gross, E. B.
Beryllium 99
Gem Stones 169
Hamilton, W. B.
Geology of the Salton Trough 73
Herz, Norman
Titanium 426
Hewett, D. F.
See under Davis, F. F.
See under Dibblee, T. AV,, Jr.
Hotz, P. E.
Nickel 279
Irwin, W. P.
Geology of the Klamath Moun-
tains 40
Also see under Smith, G. I.
Jennings, C. "W.
Peat 288
Jones, D. L.
See under Repenning, C. A.
Kelley, F. R.
Clay 126
King, P. B.
Geologic History of California 27
King, R. U.
Molybdenum 262
Kinkel, A. Robert, and Kinkel,
Arthur R., Jr.
Copper 141
Kinkel, Arthur R., Jr., and
Broderick, G. N.
Sulfur 410
Landis, E. R.
Coal 134
Lemmon, D. M.
Garnet 168
Tungsten 429
Lesure, F. G.
Feldspar 158
Mica (Muscovite, biotite, and ver-
miculite) 254
Macdonald, G. A., and Gay, T. E.
Geology of the Southern Cascade
Range, Modoc Plateau, and
Great Basin Areas in North-
eastern California 43
McNitt, J. R.
See under White, D. E.
Moore, Lyman
Iron 199
Morton, P. K.
f^admium 113
Zinc 444
Oakeshott, G. B.
Geology of the California Coast
Ranges 36
Graphite 186
Padan, J. W.
Offshore Resources (ICxclusive of
Petroleum) 280
I'arker, R. L.
Niobium and Tantalum 284
Peterson, G. L.. Gastil, R. G., and
Allison, E. C.
Geology of the Peninsular Ranges 70
Repenning, C. A., Jones, D. L., and
Addicott, W. O.
Geology of the Great Valley 48
Rice, S. J.
A.sbestos 80
Calcite, Optical Grade 114
Ross, D. C.
Quartzite and Quartz 340
Also see under Stewart, J. H.
Schambeck, F. J.
See under Smith, M. B.
Smith, A. R.
Magnesium Compounds 235
AUTHOR INDEX-Continued
Page
Smith, a. ].
Bromine HI
Calcium Chloride 117
Iodine 19S
Potash 334
Salt 356
Sodium Carbonate 3S5
Sodium Sulfate 389
Smith, G. I., and Irwin, W. P.
I^ithium 233
Smith, M. B.
Asphalt and Bituminous Rock 92
Smith, M. B., and Schambeck, F. J.
Petroleum and Natural Gas 291
Smith, AV. C.
Borax and other Boron Compounds 104
Staler, H. K.
Silver 381
Stewart, J. H., and Ross, D. C.
Geolog-y of the Great Basin South
of the 39th Parallel 59
Pa«o
Stewart, U. M.
Lead ._ 210
Stinson, M. C.
Minor Metals 258
Zirconium and Hafnium 448
Thayer, T. P.
Chromite 120
Troxel, B. W.
Wollastonite 441
Walker, G. W., and Butler, A. P.
Uranium 43G
Weber, F. H., Jr.
Barite 9 4
Weiler, C. T.
See under Burnett, J. T>.
White, D. E., and McXitt, J. ll.
Geothermal Knergy 174
WithinKton, C. F.
Gypsum and Anhydrite ISS
Wright, L. A.
Pyrophyllite 342
Talc and Soapstone 414
''2d sZToT } COMMITTEE PRINT
MINERAL AND WATER RESOURCES
OF CALIFORNIA
PART I
MINERAL RESOURCES
REPORT
OF THE
UNITED STATES GEOLOGICAL SURVEY
IN COLLABORATION WITH
THE CALIFORNIA DIVISION OF MINES
AND GEOLOGY
AND THE
UNITED STATES BUREAU OF MINES
PREPARED AT THE REQUEST OF
Senator Thomas H. Kuchel
OF CALIFORNIA
OF THE
COMMITTEE ON INTERIOR AND
INSULAR AFFAIRS
UNITED STATES SENATE
Printed for the use of the Committee on Interior and Inisular Affairs
U.S. GOVERNMENT PRINTING OFFICE
67-164 0 WASHINGTON : 1966
FOREWORD
On November 13, 1964, I requested the Secretary of the Interior
to determine if a comprehensive summary report on the mineral and
water resources of California could be prej^ared for the use of citizens,
professional personnel, and government, civic, and industrial leaders
interested in mining, water, and industrial development.
This report-, prepared in response to my request by members of the
U.S. Geological Survey, the U.S. Bureau of Reclamation, the U.S.
Bureau of Mines, the California Division of Mines and Geology, and
the California Department of Water Resources, with the cooperation
of other individuals, is a thorough, detailed, and comprehensive work
which I am sure will be of great value to all interested in the mineral
and water resources of the State of California.
I wish to express my thanks and appreciation to Secretary of the
Interior Udall and to those in his Department, to the State of Cali-
fornia agencies, and to all the individuals who contributed their efforts
in compiling this very valuable and comprehensive report.
Thomas H. Kuchel,
U.S. Senator.
LETTER OF SUBMITTAL
Department of the Interior,
Washington, D.C., March 26, 1966.
Hon. Thomas H. Kuchel,
U.S. Senator, Washington, D.C.
Dear Senator Kuchel : We are pleased to transmit herewith part I
of a summary report on the mineral and water resources of California
which has been prepared in response to your request of November 13,
1964, Part I is a summary report on the mineral resources. It has
been prepared by the Geological Survey in collaboration Avith the
California Division of Mines and Geology and the Bureau of Mines.
This report covers all mineral commodities known to exist in poten-
tially significant amounts in California. Because of the comprehen-
siveness of the report, the discussion of each commodity is necessarily
brief. The distribution and availability of the coimnodities are por-
trayed graphically in numerous maps, charts, and diagrams. It is
hoped that the report will provide the needed data and in a form
that meets with your approval.
A summary report, on the water resources of California, which you
also requested, is nearing completion. It is being prepared as a com-
panion volume to the report on minerals and will comprise Part II of
the report. The manuscript for Part II will be transmitted to you
as promptly as possible.
Smcerely yours,
Stewart L. ITdall,
Secretary of the Interior.
VII
MINERAL AND WATER RESOURCES OF CALIFORNIA
Part I. Mineral Resources
REPORT
OF THE
UNITED STATES GEOLOGICAL SURVEY
IN COLLABORATION WITH
THE CALIFORNIA DIVISION OF MINES AND GEOLOGY
AND THE
UNITED STATES BUREAU OF MINES
PREa»ARED AT THE REQUEST OF
SENATOR THOMAS H. KUCHEL
OF CALIFORNIA
OF THE
COMMITTEE ON INTERIOR AND INSULAR AFFAIRS
UNITED STATES SENATE
PREFACE
(By J. P. Albers, U.S. Geological Survey, Menlo Park, Calif.)
This report describes in siunmaiy form the mineral resources of
California and includes a brief description of the geology. The use,
mamier of occurrence, distribution, and outlook for all known mineral
commodities in the State are discussed, and, where available, statistics
on the production of the commodities are summarized.
It is the purpose of this report to present an objective appraisal of
California's mineral resources, based on information presently avail-
able. The treatment of each commodity is necessarily brief, but those
who wish to make deeper inquiry will "find the list of references after
each article useful.
The term "resources" as used in this report applies to materials in the
ground that are known to be minable, and to materials that are not
minable at present but which may come into such demand as to become
minable in the future. "Reserves" are materials that may or may not
be completely explored but may be quantitatively estimated and are
considered to be economically exploitable at the time of the estimate.
Reserves fluctuate because they are dependent on economic conditions,
technologic factors, and available information. A low-reserve figure
does not necessarily mean that the resource is near exhaustion. It may
indicate that exploration is lacking or that a depressed market has
lowered the value of the commodity to the point where the material can
no longer be considered economically exploitable. "Ore" is mineral
material that may be mined at a profit.
The subject material and outline and the selection of authors of
articles was worked out jointly by staff members of the U.S. Geological
Survey and the California Division of Mines and Geology ; the ma-
jority of the articles in this part were written by members of the U.S.
Geological Survey, the California Division of Mines and Geology, and
the U.S. Bureau of Mines, but three articles were written by university
staif members who have special knowledge of the topic discussed ; one
author, now employed by a private firm, w^as until recently with the
U.S. Bureau of Mines. The organization w4th which an author is
affiliated is shown with his name under the title of each article.
John P. Albers, of the Geological Survey, w^th the editorial and
coordination assis'tance of Richard M. Stewart, of the California Divi-
sion of Mines and Geology, assembled and edited the report.
CONTENTS
Page
The mineral industry of California 11
Topographic and geologic maps 21
Topography 23
Geologic history of California 27
Geomorphic provinces 35
Geology of California Coast Ranges 36
Geology of the Klamath Mountains 40
Geology of the southern Cascade Range, Modoc Plateau, and Great
Basin areas in northeastern California 43
Southern Cascade Range 43
Modoc Plateau 46
Great Basin 47
Geology of the Great Valley 48
Geology of the Sierra Nevada 54
Geology of the Great Basin south of the 39th parallel 59
Geology of the Mojave Desert region 62
Geology of the Transverse Ranges 66
Geology of the Peninsular Ranges 70
Geology of the Salton Trough 73
Mineral resources 77
Introduction 77
Aluminum 79
Antimony SI
Arsenic 85
Asbestos 86
Asphalt and bituminous rock 92
Barite 94
Beryllium 99
Bismuth 102
Borax and other boron compounds 104
Bromine HI
Cadmium 113
Calcite, optical grade 114
Calcium chloride 117
Carbon dioxide 119
Chromite 120
Clay 126
Coal 134
Cobalt 139
Copper^ 141
Diatomite 151
Feldspar 158
Fluorspar 165
Garnet 168
Gem stones 169
Geothermal energy i 174
Gold 179
Graphite 186
Gypsum and anhydrite 188
Iodine 198
Iron 199
Kyanite, andalusite, and related minerals ^ — 212
Lead 216
Limestone, dolomite, and lime products 221
5
6 MINERAL AND WATER RESOURCES OF CALIFORNIA
Jlineral resources — Continued. Pa^e
Lithium 233
Magnesium compounds 235
Manganese 243
Mercury 247
Mica (muscovite, biotite, and vermiculite) 254
Minor metals 258
Cesium and rubidium 259
Gallium 259
Germanium 259
Indium 260
Rhenium 260
Selenium 261
Thallium 261
Molybdenum 262
Natural gas liquids 269
Nickel 279
Niobium and tantalum 284
Offshore resources exclusive of petroleum 286
Peat 288
Petroleum and natural gas 291
Introduction 291
United States rank as world producer of oil 295
California's rank in United States production 295
Geologic occurrence 295
Economic factors affecting exploration 298
History of discovery and development 302
Discovery by prospecting near seepages, 1865-1907 302
Discovery primarily by the use of geology, 1908-1935 303
Discovery by the use of geology and reflection seismometry,
1936 to present 304
Natural gas 308
Oil and gas provinces in California 311
Los Angeles sedimentary basin 311
Ventura sedimentary basin 313
San Joaquin sedimentary basin 315
Sacramento sedimentary basin 316
Santa Maria sedimentary basin 317
Salinas-Cuyama sedimentary basin 318
Santa Cruz and Eel River sedimentary basins 319
Offshore 319
History of discovery and development offshore 321
Resources 322
Proved reserves 322
Potential resources 325
Onshore 325
Offshore 326
Selected references 327
Phosphate 328
Platinum group metals 332
Potash 334
Pumice, pumicite, perlite, and volcanic cinders 336
Pyrophyllite 342
Quartz crystal 344
Quartzite and quartz 346
Rare earths 350
Salt 356
Sand and gravel 361
• Sands, specialty 369'
Shale, expansible 374''
Silver 381
Sodium carbonate 385
Sodium sulfate 389
Stone, crushed and broken 392
Stone, dimension 400
MINERAL AND WATER RESOURCES OF CALIFORNIA 7
Mineral resources — Continued. P»so
Strontium 408
Sulfur 410
Talc and soapstone 414
Thorium 420
Tin 422
Titanium 426
Tungsten 429
Uranium 436
Vanadium 439
WoUastonite 441
Zinc 444
Zirconium and hafnium 448
ILLUSTRATIONS
Plate 1. Geologic map of California facing 450
Figure
1. Mineral production in California, 1900-1964 15
2. Rehef map of California, showing geomorphic province boundaries 24
3. Generalized stratigraphic correlation chart for California facing — 36
4. Index map of Great Valley locating selected paleogeograpbic features. 51
5. Trends in U.S. production and imports of antimony 82
6. Antimony in California 84
7. Principal asbestos deposits in California 90
8. Asphalt and bituminous rock in California 93
9. Baiite in California 96
10. Beryllium in California 101
11. Bismuth in California 103
12. Boron in California 106
13. Calcite (optical grade) in California 115
14. Production of chromite in California since 1885 in relation to total
United States production and consumption, world production, and
domestic price 121
15. Chromite districts and principal deposits in California 123
16. Clays produced in California 132
17. Coal in California 137
18. Cobalt in California 140
19. Copper production in California 1862-1964 143
20. California copper production by decades, 1862-1964, showing produc-
tion of major districts 144
21. Principal copper localities in California by size categories based on
production plus metal remaining in the deposits 146
22. Regional distribution of diatomaceous earth in California 154
23. Feldspar in California 162
24. Fluorspar in California 166
25. Selected gem stone localities in California — 172
26. Thermal springs of California, showing localities that have been drilled
for geothermal energy 176
27. California's gold production 182
28. Gold-bearing areas in California 184
29. Production of gypsum in California, 1945-64 189
30. Gypsum and anhydrite in California 191
31. Iron ore in California 205
32. Principal kyanite and andalusite deposits in California 215
33. Lead deposits in Inyo County 219
34. Principal limestone and dolomite districts in California _- 227
35. Map showing locations of plants producing magnesium compounds in
California, some areas with commercial grade dolomite, and selected
magnesite deposits — 236
36. Domestic production of magnesia from ores and brines in the United
States, 1947-63 242
37. Principal manganese mines in California 246
38. Mercury districts in California 252
39. Mica in California 257
8 MINERAL AND WATER RESOURCES OF CALIFORNIA
Figure Page
40. Molybdenum in California 267
41. Geographic distribution of natural gas liquids production in California. 270
42. Production of natural gas liquids in California, 1911-64 271
43. Production of natural gas liquids in California, by Counties, 1960-64. _ 273
44. Nickel in California 281
45. Niobium and tantalum in pegmatites in California 285
46. Peat in California 290
47. California oil fields 293
48. California gas fields and principal productive sedimentary basins 294
49. California oil and gas production in principal sedimentary basins,
according to geologic age of i ocks 299
50. Average price of California crude oil and natural gas 300
51. Imports of crude oil and natural gas into California 300
52. Oil disc very record for California by individual years 304
53. Exploratory wells for oil and gas in California 307
54. California crude oil production 308
55. Southern and central California oil and gas fields facing 308
56. Northern California dry gas fields 310
57. California gas production 311
58. California offshore oil production 323
59. Offshore oil and dry gas production in Ventura sedimentary basin, Cali-
fornia 323
60. Estimated proved reserves of crude oil and natural gas in California, on
January 1 of each year 325
61. Phosphate in California 331
62. Locations where platinum has been recovered in California 333
63. Pumice, pumicite, perlite, and volcanic cinder deposits in California.- 341
64. Pyrophyllite operations in California 343
65. Quartz crystal deposits in California 346
66. Rare-earths in California ^ 353
67. Salt deposits In California 357
68. California and U.S. sand and gravel production, 1920-64 364
69. Major sand and gravel deposits in California 368
70. Specialty sand deposits in California 373
71. Annual production of expanded shale aggregate in California 376
72. Expansible shale in California 377
73. Silver in California 382
74. Location of sodium carbonate producers in California 387
75. Sodium sulfate deposits in California 390
76. Principal crushed and broken stone quarries in California 395
77. California dimension stone production, 1887-1963 401
78. Principal sources of dimension stone in California 402
79. Strontium in California 409
80. Sulfur in California 411
81. Talc mines in California 418
82. Titanium deposits in California and types of ore 427
83. Tungsten in California 434
84. Uranium in California 437
85. Vanadium in California 440
86. Wollastonite in California 443
87. Principal zinc mines in California and types of ore 446
88. California placer deposits containing above average zircon concen-
trations 450
TABLES
Table
1. Mineral commodities in which California ranked first in production in
1963 11
2. Mineral commodities in which California has ranked in the top three
States in production at various times in recent years 11
3. Mineral production in California, 1963 and 1964 79
4. Properties of asbestos minerals 87
5. Asbestos production in California, 1887-1964 89
6. Barite deposits of California 97
MINERAL AND WATER RESOURCES OF CALIFORNIA 9
Table Pago
7. World production and United States consumption of beryllium in
short tons 100
8. Beryllium deposits in California 100
9. Principal boron compounds and minerals of California 105
10. Analyses of waters containing high concentrations of calcium chloride. _ 117
11. Percentage of carbon dioxide in natural gas from representative Cali-
fornia fields. 120
12. U.S. and California clay production, 1963 130
13. Classification of coals by rank 136
14. Range of analyses of representative California coals, as received basis.. 138
15. Copper production in California, 1862-1964 145
16. Principal copper localities in California 147
17. Principal formations containing diatomaceous earth in California 155
18. Reported feldspar deposits in California 163
19. Areas explored by drilling for geothermal energy in California, with
pertinent data 177
20. Production of electricity in kilowatt hours. The Geysers Power Plant,
Pacific Gas and Electric Co., Sonoma County, California 178
21. Distribution of calcium sulfate in California 190
22. Iron ore districts, mines, deposits, and prospects in California 202
23. United States production of kyanite and synthetic muUite, and imports
and exports of kyanite (short tons) 213
24. California consumption of limestone and dolomite during 1964 221
25. Plants producing synthetic magnesia, other magnesium compounds,
and calcined dolomite in California, 1964 237
26. Salient statistics on magnesite, magnesia, and dead-burned dolomite.. 239
27. Mica and vermiculite occurrences in California 256
28. Molybdenum deposits in California 264
29. Production of natural gas liquids in California, 1911-64 271
30. Production of natural gas liquids in California, by counties, 1954-64 — 272
31. Operating natural gasoline and cycle plants as of January 1, 1964 275
32. Comparative values of California's total mineral production and natural
gas liquids, 1954-64 278
33. Price per gallon and total value of natural gas liquids, by type, 1954-64. 279
34. Estimated proved recoverable reserves of natural gas liquids in Cali-
fornia and in the United States, December 31, 1964 279
35. Oil and gas production and reserve data for six leading producing
States 296
36. Giant oil fields in California ^- 306
37. Summary of the features of pumice, pumicite, perlite, and volcanic
cinder deposits of California 339
38. Rare-earth mineral occurrences in California 352
39. Estimated production capacity, sea water-evaporation plants in Cali-
fornia 356
40. Salt deposits with record of production in California 359
41. Principal sand and gravel producing areas (exclusive of specialty sand
operations) 366
42. Specialty sand deposits in California 372
43. Silver in California (From U.S. Geological Survey Mineral Investiga-
tions MR-34) 383
44. Chemical analyses of brines 388
45. Sodium sulfate deposits in California 391
46. Principal crushed and broken stone quarries in California 393
47. Pyrite and pyrrhotite production from which sulfur was recovered 412
48. Shipments of tungsten ore and concentrates from California mines
1906-1957, in short tons of 60 percent WO3 432
49. Tungsten mines or districts in California with combined production
and reserves exceeding 10 tons tungsten 435
67-164 O— 66— pt. I-
THE MINERAL INDUSTRY OF CALIFORNIA
(By Ian Campbell, Chief, California Division of Mines and Geology,
San Francisco, Calif.)
In 1965, 117 years after John Marshall's historic discovery of gold
at Sutter's mill, the California legislature enacted a bill (SB 265) de-
signating native gold as the official "State Mineral." In the same bill,
the legislature designated serpentine as the official "State Rock." The
one designation may be somewhat overdue; the other is assuredly
timely. For in 1852, only four years after Marshall's discovery, Cali-
fornia's gold production reached a total of more than $81,000,000 (at
the current price of gold, this would be almost $140,000,000), a figure
never since equaled. In that year serpentine was virtually unnoticed —
except as "hungry rock," i.e., known to be barren of gold and therefore
something to be shunned by prospectors.
In 1964, however, California's gold production had dropped to less
than $2,500,000 — the lowest figure since 1848. Serpentine (in the form
of chrysotile asbestos), which until very recently California had never
produced in amomits of more than a few hundreds of tons annually,
had increased in value from less than $25,000 in 1960 to nearly $4,500,-
000 in 1964, with promise of further increases over the next many years.
Wittingly or not, the legislature, in calling attention to gold and ser-
pentine, had most appropriately commemorated nearly four genera-
tions of mining history and economics.
In 1962, California became the "first state" (in population). Yet
she had already achieved more "firsts" in mineral production than had
any other state. In 1963, she stood first among the states in annual
production of :
Table 1
[In thousands]
Asbestos $1,547
Boron 54,981
Cement 147.656
Diatomite C)
Mercury 2,575
Pumice $2,017
Rare earths C)
Sand and gravel 128, 178
Talc 1, 427
Tungsten C)
1 Figures are confidential.
And California, in addition to these current "firsts," has been at
various times in recent years among the top three States in the pro-
duction of:
Table 2
Bromine
Lithium salts
Pyrite
Calcium chloride
Refractory and caustic
Sodium carbonate
Chromite
magnesia
Sodium sulfate
Feldspar
Natural gas liquids
Strontium
Gold
Peat
Sulfur ore
Gypsum
Petroleum
Tin
Iodine
Platinum
WoUastonite
Iron ore
Potash
11
12 MTNERAL AND WATER RESOURCES OF CALIFORNIA
Only three States surpass California in the value of their total
production of fuels; a few exceed California in the total value of
metallic minerals; a very few are ahead in the total of industrial
minerals. But no State comes even close to California in averaged
rank with respect to all three of the components of the minerals in-
dustry. Nor does any other State approach California in the num-
ber (80) and diversity of commercial mineral products. What has
led to this preeminence? The answers lie in the history and in the
geology of the State.
Inadequate as the early records are, there is no doubt but that
metals, nonmetals, and fuels had all been produced in California, in
small amounts, long before the coming of the Forty-niners. Yet it
was not until 1849 that mining became significant in the history or
the economy of the State. From that date, thenceforward for many
^-^ears, mining (and this meant essentially gold mining) was a domi-
nant factor. The "California gold rush," precipitated by Marshall's
1848 discovery, represented a mass movement of people and a redi-
rection of the hitherto well-established pastoral economy that, even
in the hindsight of history, is difficult fully to appraise or appreciate.
Thus the Californian of the mid-twentieth century complains, or
boasts, or stands in awe (as the case may be) of "the population ex-
plosion" that saw the State's population, between 1948 and 1960, in-
crease by a factor of about 57 ])ercent. He has forgotten (or never
knew) that between 1848 and 1860 the State's population expanded
from 14,000 to 380,000— an increase of 2700 percent ! It was gold that
brought about that phenomenal growth, and it was gold that, for many
years, principally sustained the State's burgeoning economy. Gold
constituted new wealth, provided new capital in lavish amoimts, and
made possible new investments which in turn exDanded and diversified
the economy. If California's annual productioji of gold today seems
minuscule by comparison with the production of grapes, or cotton,
or airj^lanes, or motion pictures, California should never forget the
legacy she owes to her gold which, in a ven^ real sense, made possible
the State's present preeminence and her affluent economy.
In retrosi^ect, it is a remarkable circunxstance that such an army of
gold seekers as constituted the Forty-niners and their immediate fol-
lowers, most of them wholly unsuited to, and inexperienced in, mining
practice, should have been so successful. Although it would be im-
possible to document, it would probably be a fair statement to say
that in so short a time no mining venture, before or since, has at-
tracted so large a number of people ; and that of these so few had had
any previous mining experience. Yet their suc^ess^whatever may
have been the ups and downs in the fortunes of individuals — is at-
tested by the more than half a billion dollars of gold produced in
just the first decade after the discovery. And this success — whatever
it may have owed to the perseverance and ingenuity of amateurs
turned miners — was largely conditioned by the favorable geology.
Nowhere, before or since, lias so much gold been laid out, almost ready
to hand, by nature. Here is not the pla<^e to detail the metallogenic
and geomorphic events that conspired to spread these riches along
the foothills of the Sierra Nevada and elsewhere in the State. Suffice
it to say that the values in the first, easily discovered and easily
MINERAL AND WATER RESOURCES OF CALIFORNIA 13
worked placers, provided the capital and the modicum of exerience
necessary to develop the more difficult, but often more rewarding
"hicrh bench gravels" and so on to the "drift mines" and, eventually,
the great "hydraulic mines," the gold dredges and the lode mines
Avhich, with the pittances now being added by the recent innovation
of "skin-diving for gold," have brought the State's total production
of gold to the impressive figure of more than 2i/<{ billion dollars. The
bulk of this, be it remembered, was produced when the price of gold
was only $20.67 an ounce, and when a dollar was worth many times
what it is today.
If the favorable-to-mining character of California's geology had
first been demonstrated in the distribution of j>lacer gold in a region
where it was relatively easy to win, and where life was relatively
easy to sustain, it was further demonstrated in the distribution of
mercury, which for many years was second only to gold in the State's
mineral production. Nowhere else in the world have imj^ortant de-
posits of mercury existed withm easy access of inajor deposits of
gold. Yet the fact is that the New Almaden mine, the largest pro-
ducer of mercury in North America, had been discovered in 1845 and
lay less than 100 miles from the gold of the Mother Lode! Nor
was the New Idria, se^-ond in total production to the New Almaden,
much farther away. These convenient and relatively economical
sources of quicksilver made for ready application of the amalgama-
tion process, then the most efficient method for extraction of free gold
from gangue, and thereby further enhanced the mining economy of
the State.
If the early ^old seekers were largely amateure when they arrived
at the "gold diggins," they of necessity soon became professionals.
California's isolation from the manufacturing centers of the eastern
seaboard not only called for development of ingenuity and imiovation
in local mining enterprise, but led also to local foundries, local machine
sJiops, and to adaptations to local needs — many of which contributed
to widespread improvements in mining and milling methods. The
first major transportation of water in the State (still an item of utmost
concern to California) came about in order to supply the huge hy-
draulic mines, themselves a major mining development of the time.
Philip Diedesheimer, at Georgetown, California, in 1859, perfected
square-set timbering, later to prove so important on the Comstock
lode. Stamp mills, of a size and efficiency never before dreamed of,
became realities. Years later (in 1918) another California develop-
ment, tlie Gould Furnace with its greatly increased efficiency, proved
a boon to mercury mining in the State and throughout the world.
Nor should it be forgotten that the Cottrell Filter, a significant step
in making mineral processing compatible with agriculture and even
with urbanization was initially a California development.
Nevertheless, despite discoveries of new deposits, new developments
in mining practice, and greater experience on the part of the miners,
the inexorable economics of a non-renewable resource (increasing costs
of operation and/or exhaustion of the mines) inevitably became felt
in the gold-mining industry of the State. In addition, three other
widely spaced events contributed to what currently amounts almost to
the demise of this industry. The first (in 1880) was the "Sawyer
14 MINERAL AND WATER RESOURCES OF CALIFORNIA
decision" making illegal any mining activity which dumped excessive
amounts of silt into streams, with consequent harmful effects on fishing
and agriculture. Next there came, in 1941, the somewhat misnomered
"gold mine closing act" (L-208), an order issued by the War Produc-
tion Board primarily as a means of furthering needed war industries,
but which nevertheless did effect the closing of most gold mines. And
the third factor has been the postwar continuing rise in the costs of
labor and materials which has essentially squeezed — against the pegged
price of gold of $35 an ounce — ^the remaining life out of such mines
as were able to resume production following World War II.
Because gold has constituted such a large proportion of California's
output of metallic minerals, the very significant production of other
metallic minerals has not always been fully appreciated. Mercury has
already been mentioned as antedating gold and as being currently, and
for many years past, one of the "California firsts," both in total and in
amiual rank of production. As early as the 1850's, prospectors,
whether disappointed in their gold mmes or otherwise seeking diversi-
fication, discovered and developed deposits of silver, copper, lead, and
zinc. Beginning about 1870, California was for some years the lead-
ing producer of chromite in the country, and was even exporting to
England. This industry incidentally underwent spectacular revival
in the State, under the impetus of greatly increased prices, during the
two world wars, contributing significantly to supplies of this strategic
metal. Manganese and tungsten mining have likewise been highly
responsive to war demands and price increases. Lacking war-time
bonuses and post-war subsidies, manganese is no longer being mined
in the State; tungsten — by virtue of the tremendous developments at
the Pine Creek deposit in the eastern Sierra Nevada — still is bemg
produced, along with significant amounts of by-product molybdenum.
One war-torn development, among the metal mines, has grown and
is continuing to grow : mining of iron ore. Until the onset of World
War II, California was virtually without an iron and steel industry.
Mineral economists, although aware of deposits of iron ore within the
State, had tended to discount the deposits as "too erratic" and, since
the State lacked any local sources of coal and coke, many predicted
that there would never be an iron and steel industry in the State. They
had not fully foreseen the impetus of war demands, and the needs of
the post-war expanding population. Currently, iron ore is being pro-
duced not only in amounts sufficient to supply the fully integrated
Fontana plant of the Kaiser Steel Co., but also in significant amounts
for export to Japan.
Important as all of these metallic minerals have been, and are, they
constitute today only a very minor part of California's mineral in-
dustry. Almost unheralded, the industrial minerals ("nonmetals")
long since overtook the metals in terms of value in the State's econo-
my (figure 1). The figures stand today at more than $500,000,000
annually for the industrial minerals, versus slightly less than $60,000,-
000 for the metals. And the trend of the industrial minerals has been
steeply upward for over twenty years.
MINERAL AND WATER RESOURCES OF CALIFORNIA 15
$ 1 .300
$1,252,500,000
(1957)
$998. 152.000
(1964)
503.917.000 ;■
1964) ^
$256,000,000 /^
$94,000,000-
$45,000,000
;>v:'all.metaj.s^— ^
/ $58. 441.000,
"/•>7$55,000. 000
/$2, 486.000^
;-.. (1964),r:r>
^'r;'~ — GOLD
-] 1 ^
1900 1910 192 0 1930 1940 1950 1960-64
FiGUBE 1. Mineral production in California, 1900-64,
1.200
1.100
1.000
900
800
700
600
500
400
300
2 00
100
q:
<
o
Q
o
z
o
16 MINERAL AND WATER RESOURCES OF CALIFORNIA
As far back as the late 1850's, a San Francisco physician, Dr. Jolin
A. Veatch, was spending his summers traversing the t^tate in horse and
buggy, looking for sources of borax, then in demand chiefly for its
medicinal virtues. His discovei-y of borax crystals in the muds of
Borax Lake, and the subsequent story of borax in California consti-
tutes one of the more fascinatincr records of nonmetallic mining his-
tory. It IS a story of how the geography of the industi-y shifted from
the lake muds in Lake County, to the "salt marshes" of southeastern
California and Nevada, to Death Valley and to Calico, and eventually
to Searles Lake and the Kramer district ; of how the geology and
mineralogy shifted from borax to ulexite, to colemanite, to kernite,
and now to brines and to borax again (with colemanite once more
looming over the horizon) ; and of how^ prices have dropped (vis-a-vis
the Consumer Price Index) and of how demand and production have
increased — to the point where boron and boron compounds have for
many years exceeded in value the State's gold production and have
constituted the State's principal export mineral, contributing signifi-
cantly to the "favorable balance of trade" enjoyed by the State's
economy.
If the history of California borax mining provides contrasts with
gold, other industrial minerals provide additional contrasts — with
both gold and borax. This is particularly true of the constniction
materials, especially rock, sand and gravel. These are commodities
that, unlike gold and borax and many other minerals, depend for their
demand on density of population more than upon special qualities and
rarity of occurrence. And these are commodities which, because of
their bulk, seldom enter significantly into interstate — much less inter-
national— commerce. They are therefore relatively imnimie to the
effects of changing tariifs, subsidies, import quotas, and international
cartels, and to this extent provide a less fluctuating and a sounder ele-
ment in the mineral economy. Yet sand and gravel, except such as was
mined incidental to the recovery of gold, did not even figure in the
early records of the State's mineral production. Today, with an an-
nual output of nearly 113,000,000 tons, valued at nearly $130,000,000,
sand and gravel is the State's leading mineral industry in terms of
volume, and shares with cement the top place in value among the
State's "hard minerals."
Nevertheless, the industrial minerals are not without their problems.
If the sand and gravel industry is dependent on population growth,
the spread of population is rapidly threatening to become a deterrent
to the industry, in that "suburbia" is already in competition with the
needs of the industiy for the acreage that constitutes its "ore." Like
any other mineral, suitable deposits of sand and gravel are severely
limited in their occurrences by the facts of geology. And deposits are
further limited by the facts of economics: bulk materials cannot be
moved long distances without incurring prohibitive cost. Yet, in a
number of instances, the sand and gravel industry is being "zoned out
of its own holdings" through the spread of urbanization and the lack
of imderstanding, on the part of the public, of the geology and eco-
nomics of the situation. Without an understanding, "suburbia" will
soon be in the position of denying to itself (except at greatly increased
MINERAL AND WATER RESOURCES OF CALIFORNIA 17
costs) the very materials on which its own g^o^vth (homes, streets,
schools, public buildings, etc.) depends. The problem — be it noted—
is basically a man-made problem and offers hope, therefore, that man
will eventually resolve it.
Is oil a mineral ; is natural gas a mineral ? Even to suggest that these
are minerals would raise the hackles of some semantically inclined
mineralogists; but to suggest that they are not will assuredly raise the
hacldes of every mining and petroleum engineer and economic geol-
ogist. Although the definition may be "largely of academic interest,"
the practical fact is that petroleum and related products constitute
mineral resources as truly as do gold and silver and borax and asbestos.
Principles of exploration and extraction and processing, and even of
marketing, may differ in details but in broad fundamentals of geology
and of economics they are the same. Certainly, therefore, any intro-
ductory discussion of the State's mineral industry must call attention
to the "black gold" Avhich for many years has been its premier mineral
resource. Inasmuch, however, as there is extensive discussion of this
most important industry in a following chapter, only certain salient
features will here be mentioned.
Although oil seeps and tar sands were known to the Indians and
were very locally exploited during the Spanish regime, significant
commercial production of oil did not get under way in California until
1876, with the initial development of the Newhall field. This was at
a time (further evidence that the gods continued to smile on Cali-
fornia ! ) when the production of the "yellow metal" had declined dras-
tically from the flush years of the 185d's and 1860's (see fig. 27) . As a
result the growth of the "black gold" industry came at a particularly
opportune time for the State's economy. Subsequent production rec-
ords (see fig. 54) have placed California second only to Texas in total
production of oil, and have clearly placed oil as the State's No. 1 min-
eral resource. It is of interest, too, to note that the banner year for
gold came in 1852 ; the banner year for oil, 105 years later, in 1957.
From this, one might perhaps predict that significant amounts of oil
will still be produced in the State 100 years from now, just as gold is
still a multi-million dollar industry more than 100 years after Mar-
shall's discovery. That decline in petroleum production has set in,
is shown by the charts, but that the decline is recently being arrested
is also shown. This comes about through important new discoveries —
particularly of gas fields; through improved secondary recovery
methods (primary recovery, even with modern methods, still leaves
50 to 75 percent of the oil "in the ground) ; and through adjudication
of jurisdictions which now^ permit development of off-shore oil poten-
tial, in particular of the East Wilmington field, destined to be one of
the country's great oil fields.
All of California's oil and gas occurrences are directly related to
her complex geology which — ^because of the complexity — ^^has called for
exceptionally sophisticated (and expensive) geological and geophysi-
cal approaches to the problems of discovery and exploitation. For the
same reason, successful solutions have been exceptionally rewarding.
Thus the yield of the average California oil well is anticipated to be
more than three times that of the average well in the United States,
18 MINERAL AND WATER RESOURCES OF CALIFORNIA
and in some fields as many as 10 separate zones, over depth intervals of
more than 6,000 feet, have been commercially developed. Small won-
der, then, that the California petroleum industry has long enlisted
exceptionally able management, exploration and engineering teams in
order successfully to develop this major mineral resource.
Production records for the major components of California's min-
eral industry have been given in figure 1. To what extent can growth
lines justifiably be extended into the future? Projections are no more
than predictions, but prediction can in this case be based on the facts
of geology and history. California has been peculiarly blessed with
a complex geology, doubtless in part the result of the "unease" of the
crust, described in the chapter on Geologic History of California. The
distinctive geology has in turn provided an unequalled diversity of
minerals, many in notable concentrations. The chapter headings in the
Table of Contents of this volume document the great diversity of use-
ful mineral products enjoyed by the State — a most favorable factor in
her economy. Mineral-wise, California is far from the "one-crop"
State she once was in the hey-day of gold mining. Moreover, a greater
number of different minerals (over 700 distinct species) are known to
occur in California, and more minerals (45) not as yet known any-
w^here else in the world, occur in California than in any other state.
And, mining history in California has built a tradition of exploration
and innovation — a recent example being the successful harnessing of
geothermal power at The Geysers — ^the first, and still the only such
development in North America.
With the combination of men and minerals to be found in the State,
the future of the mineral industry should indeed be bright. But there
are many who, with considerable justification, view it with misgivings.
These stem from a recognition of two trends. One of these is the
growing conflict over land use. As mining turns more and more to
open pit, and to larger and larger operations, more acreage is involved,
and more public pressure develops to insist on other uses for such
acreage, whether for recreation, for urbanization, for "wilderness,"
or just '"''anything but mining !" The other trend is towards lesser in-
volvement of fewer people in the mineral industries. This results
partly from changes within the industry whereby smaller operations,
involving in the aggregate many men, are giving way to larger oper-
ations involving huge capital outlays and often fewer men. (For ex-
ample, to install the new Redding operation of the Calaveras Cement
Co. — a relatively small operation, as some cement plants go — required
some $16,000,000 in capital outlay. On a weekend, when the mine is
shut down, the largely automated mill, which has an annual capacity
of 1,500,000 barrels, can operate with only five men ! And the con-
version a few years ago of the underground mine of the U.S. Borax
and Chemical Corp. at Kramer to an open-pit operation, and instal-
lation of a new" mill, required an initial capital investment of around
$20,000,000. Yet the number of miners and millmen has decreased
at the same time that output was being increased.) The increasing
number of mergers, and the absorption of small companies by larger
in the petroleum industry is further testimony to the changes that are
going on. The net effect of these trends — greatly amplified by popula-
tion growth, per se — is that, whereas 100 years ago almost every Cali-
MINERAL AND WATER RESOURCES OF CALIFORNIA 19
fornian had some familiarity, and many were directly involved, with
the mineral industry, today scarcely one in a thousand has any con-
cept of how dependent he is, at virtually every turn of his everyday
life, on the products of mines and oil wells. Far less does he have any
concept of mineral industry operations, economics, or geology. It is
these people who now frame the laws under which the industry must
operate. It has been well said that government — Federal, State, and
local — "calls the turns" on the fortunes of the mineral industry as
never before. California has most favorable geology; she has the
mineral resources; she has the wherewithal for maintaining a minerals
industry second to none. Will her citizens prove sufficiently know-
ledgeable to meet the challenge? That is the question that now looms
largest in California's unfolding mining history.
TOPOGRAPHIC AND GEOLOGIC MAPS
(By J. P. Albers, U.S. Geological Survey, Menlo Park, Calif.)
Topographic maps show the surface features of a region, including
mountains, valleys, rivers, lakes, and man-made features. Such maps
are essential to the comprehensive development of the natural re-
sources of the State and are extremely useful to engineers, geologists,
administrators, conservationists, foresters, economists, planners,
farmers, and many others.
Topographic maps are prepared at different scales, depending on
the map's purpose. Larger-scale maps show more details than small-
scale maps. The standard topographic map scales of the U.S. Geologi-
cal Survey are 1 : 24,000 and 1 : 62,500. A topographic quadrangle
map at scale 1:24,000 (1 inch =2,000 feet) covers a rectan^ilar area
measuring 7i/^ minutes of latitude by 71^ minutes of longitude, and
a map at 1: 62,500 scale (approximately 1 inch=l mile) covers a rec-
tangular area measuring 15 minutes of latitude by 16 minutes of longi-
tude. Topographic maps of much larger areas at scales of 1 : 250,000,
1 : 500,000, and 1 : 1,000,000 are commonly prepared by compilation
processes from the 7i/2-minute and 15-minute topographic maps.
A map showing the topography of California has been published
by the U.S. Geological Survey (1953) at a scale of 1:500,000, and
maps prepared by the Army Map Service covering 2° of longitude
by 1° of latitude at a scale of 1 : 250,000 are also available for the
entire State. Fifteen-minute quadrangle maps are available for nearly
the entire State, and 7%-minute quadrangle maps cover much of the
western part of the State. Any of these maps may be purchased by
mail from the U.S. Geological Survey, Denver, Colorado, or over the
counter at Los Angeles, Menlo Park, and San Francisco, California.
Geologic maps show the distribution of rock units at the surface of
the earth. Such maps are fundamental for the intelligent exploration,
development, and appraisal of mineral and water resources of a region,
and they are being used increasingly in planning and engineering
urban development and highway construction. The geology is gen-
erally plotted on topographic base maps, and consequently geologic
maps are usually published at the same scale as the topographic base.
Most geologic mapping is done at scales of 1 : 24,000 or 1 : 62,500 but
larger scales (1: 12,000 and larger) are becoming increasingly wide-
spread, particularly for pointing out geologic conditions and hazards
that need to be evaluated in areas of mushrooming urban development.
Large-scale maps are also commonly employed in the evaluation of
highly mineralized areas, but other scales are also employed, depend-
ing on the purpose.
A geologic map of California is being prepared by the California
Division of Mines and Geology on topographic base maps at 1 : 250,000
21
22 MINERAL AND WATER RESOURCES OF CALIFORNIA
scale. Of the 27 sheets required to cover the State, 21 had been
pubhshed at the end of 1965. Much of the geology on these sheets is
necessarily based on reconnaissance geologic mapping as less than
25 percent of the State has been mapped at scales considered adequate
for most purposes. Plate 1 of this report is a geologic map at scale
1 : 2,500,000 compiled from the 1 : 250,000-scale sheets. It therefore
portrays the geology only in a very generalized form.
TOPOGRAPHY
(By J. P. Albers, U.S. Geological Survey, Menlo Park, Calif.)
California's landscape, embracing 158,297 square miles, is, like its
geology, extremely varied. Viewed overall, the dominant topographic
features of the State are the Great Valley (also known as the Central
Valley), the Sien-a Nevada, and the Coastal mountains (fig. 2). The
Great Valley is a vast elliptical bowl 400 miles long by about 50 miles
wide whose floor stands a few tens to a few hundred feet in altitude.
It is boimded on the east by the mighty Sierra Nevada with its south-
westward extension the Tehachapi Mountains, on the northeast by
the rugged Cascade Mountains, and on the west by the Coastal moun-
tains, including the Klamath Mountains and California Coast Ranges.
The northern part of the Great Valley is drained by the southward-
flowing Sacramiento River system and the southern part is drained by
the northward-flowing San Joaquin River system. About 30 miles
west of the city of Stockton, the two drainage systems converge, and
the waters find their way to the ocean through the only exit from the
mountain-rimmed valley via San Francisco Bay and the Golden Gate.
Lofty mountain peaks that tower above precipitous gorges and
canyons characterize the contour of the Sierra Nevada. The highest
peaks, including Mount Wliitney (14,495 feet) are in the southern
part of the 385-mile-long range, and the altitude of the range crest in
general declines toward the north, where the altitude of the highest
peaks is less than 8,500 feet. The Sierra Nevada is a gigantic fault
block about 80 miles wide tilted westward, and the gentle western
slope is traversed by about a dozen major streams that flow into the
Sacramento and San Joaquin Rivers in the Great Valley. Many of
these westward-flowing streams occupy deep valleys — some as much
as half a mile deep. By far the most rugged and spectacular valley is
"The Incomparable Valley'" — Yosemite — carved largely by ice many
thousands of years ago and through which now flows the Merced River.
The east side of the Sierra Nevada through much of its length drops
precipitously into Owens Valley. In the vicinity of Momit Wliitney
the relief measures nearly 2 miles in a horizontal distance of only
6 miles.
North of the Great Valley and north of the Sierra Nevada the land-
scape is dominated by two volcanic mountains, Lassen Peak (10,457
feet) , and towering Mount Shasta (14,162 feet) . East of these peaks
is the Modoc Plateau with an average altitude of about 5,000 feet but
above which numerous volcanic cones rise as much as 2,000 feet. In
the extreme northeast comer of the State, the rugged Warner Moun-
tains, culminating in Eagle Peak (9,883 feet), tower nearly a mile
above the general level of the Plateau.
Northwest of the Great Valley is an area of complex rugged topog-
raphy known as the Klamath Mountains. The highest peaks — Mount
23
24
MINERAL AND WATER RESOURCES OF CALIFORNIA
Eddy, and Thompson Peak— ascend to about 9,000 feet, and the prni-
cipal rivere— the Khimath and Trinity— have cut deep twistnig gorges.
In contrast to" the Khimath Mountains, the California Coast Kanges,
extending for nearly 600 miles south-southeast from the Oregon
border, and lying between the Great Valley and the ocean, are mark-
edly linear in character. They consist of numerous, often mdistnict,
ridges from 2,000 to 7,500 feet high separated by the valleys of such
rivers as the Eel, Mad, Russian, and Salinas, as well as smaller
streams.
. {' A-i^
FiGUBE 2. Relief map of California, showing geomorphic province boundaries.
MINERAL AND WATER RESOURCES OF CALIFORNIA 25
South and southeast of the Sierra Nevada, and extending to the
California border at the Colorado Eiver is a great expanse of desert
terrain characterized by short rugged mountain ranges, immense sandy
valleys, and dried lake bottoms. Most of this area is known as the
Mojave Desert, but the extreme sovithem part of the area is referred
to as the Colorado Desert (Salton Trough geomorphic province). A
feature peculiar to the region is that most of the rivers dry up in
the valleys by evaporation. The Salton Sea in the southern part of
the desert region is about 250 feet below sea level and the highest
peaks in the region rise to nearly 7,500 feet.
The region north of the Mojave Desert and east of the Sierra
Nevada is also desert, made up of extremely rugged, linear ranges
that attain altitudes of more than 14,000 feet. The highest peak is
White Mountain Peak (14,242 feet) near the Nevada border. Other
prominent topographic features of this region, which is part of the
Great Basin geomorphic province, are Owens Valley and Death
Valley; the lat'ter includes the lowest point on the North American
Continent at 282 feet below sea level. This lowest point is only 80
miles from Mount "V^Hiitney, the highest point in the conterminous
United States.
West of the Mojave Desert and south of the Great Valley and Coast
Ranges a group of linear ranges trends generally west, across the
northwestward grain of topography that typifies much of the rest of
the State. These ranges, of which Santa Rosa and Santa Cruz Islands
are a seaward extension, attain maximum altitudes of about 10,000
feet m the San Gabriel Mountains just north of Los Angeles. The
metropolitan area of Los Angeles is built on a broad coastal valley
that stands in general only a few^ tens of feet above sea level. Hence,
the relief in the immediate vicinity is nearly 2 miles. Southeast of
the valley in which Los Angeles is situated a group of northwest-
trending ranges extends southward into Baja California and is known
collectively as the Peninsular Ranges. The highest peak in these
ranges (San Jacinto) rises to 10,831 feet but the general altitude of
the range crests is variable and in general much lower.
67-164 O — 6i6— pt. I-
GEOLOGIC HISTORY OF CALIFORNIA
(By P. B. King, U.S. Geological Survey, Menlo Park, Calif.)
To the earth scientist, California is a region of surpassing interest,
as it is a virtual laboratory of geology in the making. Scientists and
non-scientists alike are aware of its frequent earthquakes, some of
destructive intensity. These are manifestations of the region's uneasy
crust; the geologist finds even more eloquent manifestations of such
unease in the great faults that interlace the State, along which the
rocks have been shifted even in modern time, and in the steep up-
ending of some of the very youngest stratified rocks.
California's crustal unease is related to its coastal position; the
State is, in fact, but one segment of a zone of unease that extends
nearly around the Pacific Ocean border, into South America in one
direction, and through Alaska, Japan, and Indonesia, in the other,
whose bolder manifestations are its many erupting volcanoes and
destructive earthquakes. California is the daughter of the North
American continent and the Pacific Ocean basin; according to one
plausible hypothesis it was once a part of the ocean basin, and since has
been built up by earth forces to become part of the continent.
Mostly, we know California's geologic history during the last 230
million years (during Mesozoic and Cenozoic times). The record of
earlier times is known only in places ; elsewhere it has been obliterated
by the crowded events of later times.
PRECAMBRIAN AND PALEOZOIC TIME
The record of earlier events is most plentiful nearest the continental
interior — in the desert ranges east of the Sierra Navada and in south-
eastern California (the Great Basin and Mojave Desert of the map).
Here, the oldest rocks that emerge are a basement complex of Pre-
cambrian granites and gneisses that has yielded isotopic ages of 1,000
million to 1,300 million years. (Some granites and gneisses of about
the same age also occur nearer the coast in the highly faulted Trans-
verse Ranges north of Los Angeles and San Bernardino, but their re-
lations to the surrounding rocks are not as"clear.) In the desert
ranges this basement is followed in places by sedimentary strata of
younger Precambrian age, and is covered even more widely by Paleo-
zoic strata (formed between 600 million and 230 millions years ago) ;
in some areas the Latter total 10,000 or 20,000 feet in thickness. For
the most part, these strata are the products of sedimentation in shallow,
quiet seas which spread from time to time over the edges of the conti-
nent. Many of the strata are limestone, containing fossils of shelly
marine organisms; some strata are quartz sandstone and mudstone, de-
rived from the waste of the continental interior.
Paleozoic strata are preserved farther west, in the Sierra Nevada
and Klamath Mountains, but in smaller fragments that are greatly
27
28 MINERAL AND WATER RESOURCES OF CALIFORNIA
interrupted by younger rocks. Here limestone is very subordinate,
and most of the strata are mudstone and coarser, poorly washed, dirty
sediments (graywackes), interrupted in places by lava flows, some of
which contain a pillow structure which indicates that they were
erupted under water. In this western area we have seemingly entered
another Paleozoic world — one not truly a part of the continent, but
rather, a world along the border of the Pacific Ocean.
MESOZOIC TIME
In the Sierra Nevada and Klamath Mountains these Paleozoic strata
are succeeded by others of Triassic and Jurassic age (formed between
230 and 135 million years ago), which are so similar to them that they
are difficult to distinguish except for occasional happy discoveries
of diagnostic fossils. Evidentlv the world of the Pacific Ocean border
still persisted here in these times — with its muddy and dirty sediments
and its eruption of submarine lavas.
But mighty events were in the making, which reached a climax
late in Jurassic time. In the Sierra Nevada we find that all the
strata — Paleozoic, Triassic, and Jurassic — have been turned steeply on
end, and have been so changed by heat and pressure that they are now
honifels, slate, or even crystalline schist. They have, further, been
invaded, distended, or broken off by granitic rocks, which ascended
into them from deeper levels in the crust. In the western foothills of
the Sierra Nevada the granitic rocks form small dispersed bodies, but
in the higher parts of the present range to the east they coalesce into
a vast, nearly continuous body, known as the "Sierra Nevada batho-
lith." Emplacement of the granitic rocks occurred during and after
the upending of the strata in which they are embedded; isotopic de-
terminations indicate that emplacement extended through a period of
nearly 100 million years, or from early in the Jurassic until late in
the Cretaceous, but the greatest volumes were emplaced mainly dur-
ing Late Jurassic and Early Cretaceous times.
Similar granitic rocks, enclosing small to large remnants of the
earlier strata, occur in the higher mountains throughout the length of
California — the Klamath Mountains, the Sierra Nevada, the Trans-
verse Ranges, and the Peninsular Ranges (from which they continue
southward into Baja California). An outlier of such rocks occurs
nearer the Pacific in a long strip in the Coast Ranges south of San
Francisco Bay ; these rocks front the coast in the northern Santa Lucia
Range, and project at sea in the Farallon Islands.
These mighty events — upending of the strata, emplacement of
granitic rocks, and the rest — produced mountain ranges which are
the first in California for which there is good documentation. The
events have been called the "Nevadan orogeny." By this orogeny, a
belt of considerable width was subtracted from the Pacific Ocean bor-
der and was added to the North American continent.
During and after the orogeny, in Late Jurassic and Cretaceous time
(140 to 70 million years ago), sedimentation continued along the ocean
border, west of the newly formed mountain ranges. Remnants of these
younger sediments lap up on the edge of the deformed rocks of the
Sierra Nevada, as thougli toward a shoreline. Farther west, along the
west side of the Great Valley, they attain a thickness of 20,000 to 30,000
MINERAL AND WATER RESOURCES OF CALIFORNIA 29
feet and have been called tlie Knoxville, Paskenta, Horsetown, and
Chico Formations. These are a vast sequence of dominantly muddy
sedimentary rocks, with frequent thin sandy intercalations, that con-
tain shelly fossils in many places. Probably they were laid down on a
shelf at the edsre of the continent.
A significant feature of these Upper Jurassic and Cretaceous sedi-
mentary rocks is the nature of their feldspar content. Mineral ogical
studies indicate that they contain grains of potassium feldspar, and
that these grains are rather sparse in the lower beds but become very
abundant in the higher beds, where they dominate over all other kinds
of feldspar. Potassium feldspar is characteristic of coarse granitic
rocks like those in the Sierra Nevada and elsewhere in the Nevadan
orogenic belt, and the increasing abundance of its grains in the higher
strata indicates that as time went on the granitic rocks of this orogenic
belt were being more and more penetrated and worn down by erosion.
Within the Coast Ranges west of the Great Valley, however, the
place of these shelf sediments is taken by a more enigmatic sequence,
the Franciscan Formation. The Franciscan contains fewer fossils, but
^\^hat fossils have been found indicate that it was laid down at nearly
the same time as the shelf sediments to the east. The Franciscan is a
mass of great but unknown thickness, pervasively sheared and dis-
turbed, composed of mudstone and coarser dirty sedimentary rocks
(graywackes), pillow lavas, bedded chert, glaucophane schist, and
rare limestone lenses. Seemingly it was deposited in much deeper
water than the shelf sediments previously described, and farther out
from the Pacific Ocean shoreline.
CENOZOIC TIME
The stage was now set for the evolution of California into its pres-
ent form, which was accomplished during Cenozoic time, or during
the last 70 million years.
Seerra Nevada
During the early part of this time the site of the Sierra Nevada had
been worn down to low hills and ridges, representing the stumps
of the mountains that were produced during the Nevadan orogeny.
Streams with gentle gradients drained westward across it, heading
somewhere east of the present crest. Their ancient chamiels are still
preserved in places on the hilltops of the Sierra Nevada, filled with
water- worn gravels — the "auriferous gravels" so eagerly sought by
the 49'ers and their successors. During Miocene time (25 to 12 million
years ago) the northern half of the range was also buried by sheets
of lava and volcanic debris, related to the volcanism in the Cascade
Range to the north (see below) .
The present Sierra Nevada occupies only part of the area of the
earlier Nevadan mountains, which had extended the length of Cali-
fornia and beyond to the north, south, and east. The part which forms
the present range was blocked out after ^Miocene time (perhaps begin-
ning 12 million years ago) . Then, the block was broken from the land
to the east along great faults; its eastern side was raised along the
faults to form the present range crest, and the western slope was tilted
toward the Great Valley (which is, in fact, the depressed and buried
western part of the block). This uplift was progressive and was ac-
30 MINERAL AND WATER RESOURCES OF CALIFORNIA
complished during several stages. It was virtually completed by the
end of Pliocene time (about 3 million years ago), although some fault-
ing and uplift continued during succeeding Quaternary time.
Northeastern California
The northe-astern corner of California is quite different ivoni the
remainder of the State, as it is built almost wholly of young volcanic
rocks ; it is one edge of an extensive volcanic region that extends far
northward and northeastward across Oregon, Washington, and Idaho.
Here, especially during Miocene and Pliocene time, lava flows and
sheets of fragmental volcanic debris spread widely over the land as a
result of eruptions from fissures and volcanic vents. These rocks range
in composition from basalt through andesite to rhyolite. The eruptive
material accumulated to great thickness; in the Warner Range in the
northeasternmost part of the State at least 7,500 feet of the accumula-
tions have been raised to view by faulting, with their base not visible.
Farther west, the volcanic accumulations have built up the Cascade
Range that extends with increasing height into Oregon.
Volcanic activity continued into late Cenozoic time. In the western
part of the volcanic area, two great volcanic cones that dominate the
landscape of northern California — Mount Shasta (altitude 14,162
feet) and Mount Lassen (altitude 10,457 feet) — were formed veiy late
in geologic time. The lofty cone of Shasta, covered most of the year
by snow and supporting a few permanent glaciers, seems now to be
inactive, but the lesser cone, Lassen, underwent a minor eruption in
1915 — the only volcano south of Alaska that has erupted during mod-
em times within the continental United States. Surrounding these
larger cones are myriads of smaller cones and craters which, as on
their surrounding lava flows and other volcanic products, vegetation
has scarcely regained its foothold — all testifying the relative recency
of volcanic activity in this part of California.
Coastal Mountains
During the evolution of the present Sierra Nevada and Cascade
Range in Cenozoic time many more and varied events were transpir-
ing on the sites of the coastal momitains to the west — the Coast Ranges
north and south of San Francisco Bay, the Transverse Ranges, and the
Peninsular Ranges.
An outstanding feature of these ranges is the high-angle faults that
traverse them, which have had a large but uncertain influence on tlieir
evolution. The largest and most famous of these faults is the San
Andreas, which extends nearly the length of California, from Punt a
Arena north of San Francisco, 620 miles southeastward, almost to if
not across the Mexican border. But branching from or parallelmg
the San Andreas are other faults of nearly equal magnitude, and they
are crossed in the region of the Transverse Ranges by other high-angle
and low-angle faults of east- west trend.
Nearly everything about these high-angle faults has been hotly
debated by geologists — the time of their inception, their subsequent
history, and the magnitude and nature of the movements among them.
MINERAL AND WATER RESOURCES OF CALIFORNIA 31
Most of the streams which cross the San Andreas fault turn to the
right at the fauU line for a few hundred or a thousand feet before
resuming their normal course, giving eloquent testimony of a lateral
shift of the geography on the two sides by these amounts during the
last 25,000 years or so ; similar shifts of a few feet occurred on the San
Andreas fault during the San Francisco earthquake of 1906. Can
movements of the same kind be projected farther into the past?
The Temblor Range westj>f Bakersfield, bordering the San Andreas
fault on the east, is tormecT chiefly of Miocene marine strata (25 mil-
lion to 12 million years old), which contain masses of shattered blocks
of granitic and metamorphic rocks that taper to the east — evidently
landslide debris derived from highlands west of the fault. Yet just
west of [he faiiU, in the latitude of the Temblor Range the surface is
now formed only of non-marine Miocene strata. The highlands from
which the landslides came have disappeared, and there is a strong sus-
picion that they have been shifted from their Miocene location by
lateral movement along the San Andreas fault; a possible source of
the landslide material is in highlands of granitic and metamorphic
rocks on the west side of the fault which are now 60 to 80 miles to the
f northwest.
This, and similar lines of evidence, suggest the existence of the San
Andreas and other faults at least during the last 25 million years.
But still greater anomalies exist in the Jurassic and Cretjiceous_gra-
nitic and stratified rocks, which are commonly quite unlike on the
opposite sides of the faults. For a long distance south of San Fran-
cisco, for example, the older rocks east of the San Andreas fault are
Franciscan Formation, and those west of it are granitic and meta-
morphic. Also, distinctive granitic and metamorphic rocks west of
the San Andreas fault in the longitude of Los Angeles are very much
like those east of the fault near the Salton Sea, 130 miles to the south-
east. The full meaning of these anomalies remains to be explained,
but they imply not only the existence of high-angle faults before Mio-
cene time, but of very great movements along them, whether lateral
or otherwise.
If lateral shifts in the position of the blocks enclosed by the high-an-
gle faults lias been as extensive and as long-persistent as has been sug-
gested, there is a large factor of uncertainty in any attempt to recon-
struct the succession of geogi-aphies of California during Cenozoic
time.
Almost as striking as the high- angle faulting in the coastal moun-
tains is the strong folding and tilting of their strata — not only of the
earlier Jurassic and Cretaceous strata, but also of those which formed
during Cenozoic time, including even some of the yoimgest. The rela-
tion (or lack of it) between this tilting and folding and the high-
angle faulting remains one of the vexing problems of California
geology.
The record of tilting and folding in the coastal mountains of Cali-
fornia during Cenozoic time is unusually well documented, because it
went on hand in hand wnth sedimentation. Thus, strata which were
folded at some time are likely to have been eroded, and their eroded
surface to be overlain unconformably by younger strata — the strata
both below and above the unconfonnity (that is, the strata which
32 MINERAL AND WATER RESOURCES OF CALIFORNIA
were laid down before and after the folding) being datable by means
of their contained fossils.
The stratigraphic sequences in the coastal mountains of California
contain many such unconformities, indicating that folding occurred at
many times. Moreover, the magnitude, or even the existence of the
unconformities varies greatly from place to place, indicating that each
folding was essentially a local event. A record so complex is difficult
to generalize into any climaxes or widespread orogeny, but it seeins
possible that there were several gross times of orogeny, or genuine
formation of mountains, as we shall see.
The results of these movements are suggested by the reconstructions
of the geography, in the form of paleogeographic maps, wliich have
been made of the coastal area of California for various stages of Ceno-
zoic time. These reconstructions indicate that parts of the area were
at various depths beneath the sea and received marine deposits, that
other parts were low plains or basins along the coast that received
non-marine deposits, and that still other parts were hills or moun-
tain ridges that were undergoing erosion. Many of these ridges proj-
ected as islands or peninsulas, surrounded or nearl)^ so by the sea.
The geography of all the coastal area through Cenezoic time was thus
much like that which still persists in southern California — with the
otfshore Channel Islands surrounded by shallow to deep marine waters,
and the mountain-girt plains or basins onshore, such as the Los An-
geles and Ventura basins.
The reconst met ions of the geograjihy during the Cenozoic show
great variations through time (which incidentally implies the ephem-
eral nature of the seemingly immutable present geography of south-
ern California). Seas waxed and waned in extent, mountain ranges
cam« up only to disappear — all presumably in response to succe^ive
pulses of folding, and possibly also to movements along the high-
angle faults.
The deposits laid down on the sites of the present coastal mountains
are largely of clastic nature. Marine deposits that were principally
mud and sand in varying proportions, are now distinctive formations
of shale and sandstone. Gravelly beds occur near some of the former
shorelines, and dominate altogether in some of the non-marine areas
farther inland. Some deposits contain volcanic debris and interbedded
lava flows, especially those of Miocene age. Among the non-clastic
deposits, limestone is either lacking altogether or is very subordinate;
much more important are the diatom-bearing siliceous shales, altered
in part to chert, whose white, thin-bedded outcrops are a characteristic
feature of the Coast Range landscape. They are typified by the
Miocene Monterey Shale.
The Cretaceous and older deposits of the coastal mountains seem
nearly everywhere to be unconformable beneath the Cenozoic deposits,
as though an important orogeny occurred before the latter were laid
down. In some areas, to be sure, the Cretaceous is succeeded by Pale-
ocene. Eocene, and younger strata, and any intervening break is little
apparent. Elsewhere, howeA'er, much younger Cenozoic strata lie on
the deeply eroded surface of the Cretaceous and older rocks, as a result
of movements near the end of Cretaceous time and later. North and
south of San Francisco Bay and west of the San Andreas fault, Mio-
MINERAL AND WATER RESOURCES OF CALIFORNIA 33
cene strata have been deposited directly over Cretaceous granites of
deep-seated origin. One can picture these granites as having been
forced up into mountain ridges late in Cretaceous or early in Cenozoic
time, and the ridges not worn down to low gi'ound again until the
Miocene.
Miocene time (25 million to 12 million years ago) marked a great
spreading of the seas and their deposits over the site of thg^ coastal
mountains, and eastward across the Great Valley towardTThe SierFa
Nevada, where the marine deposits pass into deposits laid down on the
land. But a succession of movements in the later part of Miocene time
produced much folding and faulting of the Miocene and older strata,
and raised many areas into lands or even mountains — all adding up to
a general time of orogeny.
After this orogeny, marine incursions in the area of the coastal moun-
tains never equalled their former extent. DuringXlkiiieufi-aiid Quater-
nary time (the last 12 million years), sedimentation was confined to
smaller, generally mountain-girt areas — embayments along the coast
which received marine deposits, and basins farther inland which
received non-marine deposits; for part of the time, however, seas also
extended over much of the San Joaquin Valley. Notably among the
coastal embayments are the Los^Ajlgeles and Ventura basins, which
received as much as 177000 feet of the younger Cenozoic marine de-
posits. Tliese basins subsided very rapidly early in Pliocene time and
were covered to great depth by marine water; thereafter, they gradu-
ally filled with sediments, whose contained Foraminifera indicate that
they were laid down in progessively shallower water, until filling of
the basins was completed.
During later Cenozoic time, as earlier, sedimentation was inter-
rupted from time to time and place to place by folding and faulting.
Important movements occurred in places during the Pliocene, but the
last climax of movement was during the middle of the Pleistocene, one
or two million years ago; this has been called the "Coast Range" or
"Pasadenan orogeny." It is well displayed in the Palos Verdes Hills
southwest of Los Angeles, where older Pleistocene marine deposits
liave been up-ended and folded to the same extent as the strata beneath,
and their eroded surfaces overlain by later Pleistocene marine terrace
deposits wliich have been uplifted from beneath the sea, but are other-
wise only gently tilted.
Manifestations of this orogeny also occur in the Ventura basin, and
at many other places farther north, but its effects were variable — in
some places producing steep folding of the older Pleistocene strata,
in others vertical uplift of mountain areas with little accompanying
folding, and in still others little or no disturbance between the older
and younger Pleistocene deposits. Nevertheless, this orogeny, com-
bined with the times of defonnation which preceded it, has made the
coastal mountains of California essentially what they are today. Sub-
sequent modifications have been minor, although, as we have seen,
California is still an uneasy land.
A final feature of coastal California deserves mention, as an indica-
tion of the fluctuating relations betAveen sea and land. All along the
coast one can observe terraces on the mountain slopes, rising step-like
from the sea. The lowest terraces, a few hundred feet or less above
34 MESTERAL AND WATER RESOURCES OF CALIFORNIA
the present sea, are well preserved and are covered by deposits con-
taining marine shells ; clearly, these are old shoreline or beach deposits,
now raised above the water. The higher terraces, some more than a
thousand feet above the water, are progressively more and more
eroded and destroyed the higher one ascends, yet many of these pre-
serve marine deposits also.
Modt^rn oceanographic surveys offshore have produced the addi-
tional interesting fact that much of the sea bottom sloping away from
the land is terraced also. Former shorelines thus exist, not only
above present sea level, but at least 400 feet beneath it. Sea level
along the California coast has thus not only fluctuated downward,
but upward.
Great fluctuations in sea level with respect to the land along the
Calif orina coast are thus indicated. However, at least a part of these
fluctuations were not caused by actual crustal movement ; the locking
up of ocean water in the great continental glaciers during the Pleis-
tocene ice ages, and tlie subsequent melting of the glaciers, produced
worldwide variations in sea level amounting to hundreds of feet, both
below and above present sea level. Nevertheless, the higher marine
terraces along the California coast could not easily have been produced
in this manner, and these at least imply that various parts of the
coast have been greatly uplifted at very late periods in geologic time.
GEOMORPHIC PROVINCES
(By J. P. Albers, U.S. Geological Survey, Menlo Park, Calif.)
Because of the size of Califoniia and _its extremely varied and
complex geology, it is desirable to divide the State into eleven physical
or geomorphic provinces and describe the geology of each of these
separately. Each province is characterized by rather similar land
forms or combinations of land forms throughout its area, and by a
geologic record that contrasts with that of neighboring provinces,
especiall}^ in the later part of its geologic history. Certain kinds of
mineral deposits tend to occur within particular geomorphic provinces.
The eleven geomorphic provinces into which California is divided
are (fig. 2) : (1) Coa^t Riuiges — a system of noi*thwest-t rending lon-
gitudinal mount a in ranges made up of Mesozoic and Cenozoic rocks,
controlled by. faulting and folding; (2) Klamath Momitains — a group
of complex rugged momitains made of Paleozoic and Mesozoic rocks
intruded by gi-anitic and ultramafic rocks, and characterized by ir-
regular drainage; (3) Southern Cascade Mountains — a chain of vol-
canic mountains most prominent of which are Mount Shasta and Las-
sen Peak ; (4) Modoc Plateau — a plateau-like surface built of volcanic
rocks, bomided indefinitely on the west by the Cascade Mountains and
on the east by the Great Basin ; (5) Sierra Nevada — a great westward-
tilted fault block made mainly of granitic rocks, subordinate Paleozoic
and Mesozoic sedimentary and volcanic rocks, numerous inclusions and
pendants of metamorphic rocks, and elongate bodies of ultramafic
rocks; (6) Great Valley (also known as the Central Valley) — an el-
liptical plain bounded by mountains on all sides and underlain by
Mesozoic and Cenozoic rocks; (7) Great Basin — northwest-trending
fault-block mountains made of Precambrian to Cenozoic rocks, and
broad intervening alluvial-filled valleys and playas with no drainage
to the sea; (8) Transverse Ranges — west-trending ranges made of
Precambrian to Cenozoic rocks; (9) Mojave Desert — area wedged be-
tween San Andreas and Garlock faults and consisting of isolated
northwest-trending mountain ranges made of Precambrian to Cenozoic
rocks ; well over 50 percent of the terrain is broad intermontane val-
leys with playas and interior drainage; (10) Salton Trough — a low-
lying desert basin filled with alluvial deposits; the Salton Sea is a
promment feature; (11) Peninsular Ranges — northwest-trending
ranges made chiefly of Mesozoic granitic and metamorphic rocks.
The geology of the individual provinces is described on subsequent
pages, following a resume of the geologic history of the State. The
correlation chart (fig. 3) gives in generalized form the sequence
and age of formations in the individual provinces and the approximate
correlation of units between provinces. The authors of the individual
province descriptions are responsible for the stratigraphic column
given for their province. The stratigraphic nomenclature and age
35
36 MINERAL AND WATER RESOURCES OF CALIFORNIA
assignments used in this report, are derived from many published
sources and do not necessarily follow the usage of the U.S. Geological
Survey.
GEOLOGY OF THE CALIFORNIA COAST RANGES
(G. B. Oakeshott, California Division of Mines and Geology, San Francisco,
Calif.)
The Coast Ranges province includes a series of north-northwest-
trending mountain ranges and intermontane valleys bounded on the
east by the Great Valley and on the west by the Pacific Ocean. A
narrow segment of the province extends northward into coastal
Oregon. The boundary between the northern Coast Ranges (north of
San Francisco Bay) and the Klamath Mountains province is the South
Fork Mountain fault zone. The south end of the southern Coast
Ranges (south of San Francisco Bay) is marked by the abrupt change
to east-west topographic and structural trends of the Transverse
Ranges in Santa Barbara and Ventura Counties.
The Coast Ranges mclude numerous rugged, individual mountain
ranges which extend in elevation from sea level to maximum heights
of 6,000 to 7,000 feet; they are separated by short, narrow, inter-
montane valleys.
Geology of the province is extremely complex. Each of the ranges
has had a more or less independent and individual history, although
major episodes in that history link the Coast Ranges into a province
which is geologically and physiogr^phically distinctive.
The Precambrian history of the Coast Ranges is unknown as no
rocks of that age have been recognized. Neither are there any rock
formations of known Paleozoic or Triassic age, although it is quite
likely that the Sur Series represents part of this time, perhaps late
Paleozoic.
Great thicknesses of Upper Jurassic to Recent sedimentary, vol-
canic, and plutonic rocks reveal a complex history of deposition on the
continental shelves and in deep, narrow marine troughs. Intermittent
volcanism, plutonic intrusion, and orogenic activity were inter-
spersed throughout this time. The last major orogeny, which de-
veloped the present "Coast Ranges province," occurred during late
Pliocene to mid-Pleistocene time. Late Jurassic orogeny and granitic
intrusion affected the Coast Range region to some extent as it did the
Transverse Ranges, Sierra Nevada, Klamath Mountains, and much of
the rest of California. Similarly, mid-to-Late Cretaceous mountain
building took place, accompanied by the greatest and most widespread
granitic invasions of California's history. Intermittent and local
crustal disturbances occurred throughout the Tertiary, culminating
in the Pliocene and Pleistocene Coast Range orogeny. This involved
the most profound deformation in the history of the Coast Ranges.
Basement rocks of the Coast Ranges consist of two groups: (1)
Upper Jurassic to Upper Cretaceous rocks of the Franciscan Forma-
tion that were deposited in deep offshore troughs, or eugeosynclines,
and (2) the Upper Paleozoic ( ? ) gneisses and schists of the Sur Series
intruded by Upper Jurassic ( ? ) and Upper Cretaceous granitic rocks.
Older rocks have not been found beneath either of these major groups.
CO
CO
o
1^
a
I
(O
<o
Colo
T109 t>
FiouRE 3. Generalized atratigraphic correlation chart for California.
^F^\
MINERAL AND WATER RESOURCES OF CALIFORNIA 37
The Sur Series consists of gneisses, schists, and marble — formed from
thick sedimentary and volcanic formations that were affected by high-
grade metamorphism. They crop out most extensively in the Santa
Lucia and Santa Cruz Mountains. Rocks of the Sur Series, and the
granitic rocks that intrude them, yield extremely valuable crushed
and broken stone, and limestone for the manufacture of cement. The
Sur Series is also a major source of dolomite.
The Franciscan Formation consists of at least 20,000 feet of gray-
^yacke, dark shale, metavolcanic rocks, chert, minor limestone, and
metamorphic rocks of the blue-schist and green-schist facies. The
Franciscan is intruded by peridotite and serpentine, which perhaps
also constitute the material of the upper mantle on which the Fran-
ciscan was deposited. These masses of ultramafic rock in places con-
tain deposits of chromite, and are also the parent rocks of the nickel-
bearing laterites. These rocks are also the source of extensive asbestos
deposits being mined in San Benito and adjacent Fresno counties.
The Franciscan Formation supplies crushed and broken stone and
riprap, and has been a major source of manganese in the past. Fran-
ciscan rocks are found in all parts of the Coast Ranges except in the
20- to 40-mile-wide strip between the San Andreas and Nacimiento
fault zones.
A major group of rocks with an aggregate thickness on the order
of 30,000 feet represents all epochs from Late Jurassic to Late Cretace-
ous time. These unmetamorphosed shelf-facies rocks — sandstone,
shale, siltstone, and minor conglomerate and limestone — lie on the Sur
Series and Franciscan Formation and are also contemporaneous (at
least, in part) with the Franciscan Formation and the granitic rocks.
The thickest, most continuous sections of the shelf-facies sedimentary
rocks dip under the Great Valley from the east flanks of the Diablo and
Mendocino Ranges. Lower and Upper Cretaceous rocks are predomi-
nantly dark sandstone (graywacke) and arkose (granitic sandstone)
Avith minor shale and conglomerate. They contain larger proportions
of K-feldspar grains than does the Franciscan.
Cenozoic formations comprise a great variety of sedimentary and
volcanic rocks but all are apparently of shallow marine (shelf and
slope) and continental origin. Rapid lateral changes in facies and
thicknesses reflect intermittent localized folding, faulting, and volcan-
ism. Those changes are most marked at the margins of the basins
and ranges. Paleocene marine sedimentary rocks are quite similar to
those in Upper Cretaceous formations, but are not as thick or as wide-
spread. Progressively more restricted seaways from Paleocene to late
Eocene time limited the deposition of Eocene sands, muds, and clays
to narrow basins in the area of the Coast Ranges.
From late Eocene to middle Miocene time, seaways in the Coast
Range region were severely restricted and climates became markedly
seasonal and locally semi-arid. Conglomerate, sandstone, shale, and
mudstone of these epochs include shallow-marine materials and exten-
sively distributed, and locally thick continental red beds. Oligocene
formations crop out only in the southern Coast Range; probably the
northern Coast Range area was above sea level during Oligocene time.
In the Santa Cruz, Santa Lucia, and Diablo Ranges, shallow-water
marine sandstone, shale, some conglomerate, and local tuff beds repre-
MINERAL AND WATER RESOURCES OF CALIFORNIA 37
The Sur Series consists of gneisses, schists, and marble — formed from
thick sedimentary and volcanic formations that were affected by high-
grade metamorphism. They crop out most extensively in the Santa
Lucia and Santa Cruz Mountains. Rocks of the Sur Series, and the
granitic rocks that intrude them, yield extremely valuable crushed
and broken stone, and limestone for the manufacture of cement. The
Sur Series is also a major source of dolomite.
The Franciscan Formation consists of at least 20,000 feet of gray-
wacke, dark shale, metavolcanic rocks, chert, minor limestone, and
metamorphic rocks of the blue-schist and green-schist facies. The
Franciscan is intruded by peridotite and serpentine, which perhaps
also constitute the material of the upper mantle on which the Fran-
ciscan was deposited. These masses of ultramafic rock in places con-
tain deposits of chromite, and are also the parent rocks of the nickel-
bearing laterites. These rocks are also the source of extensive asbestos
deposits being mined in San Benito and adjacent Fresno counties.
The Franciscan Formation supplies crushed and broken stone and
riprap, and has been a major source of manganese in the past. Fran-
ciscan rocks are found in all parts of the Coast Ranges except in the
20- to 40-mile-wide strip between the San Andreas and Nacimiento
fault zones.
A major group of rocks with an aggregate thickness on the order
of 30,000 feet represents all epochs from Late Jurassic to Late Cretace-
ous time. These unmetamorphosed shelf-facies rocks — sandstone,
shale, siltstone, and minor conglomerate and limestone — lie on the Sur
Series and Franciscan Formation and are also contemporaneous (at
least, in part) with the Franciscan Formation and the granitic rocks.
The thickest, most continuous sections of the shelf-facies sedimentary
rocks dip under the Great Valley from the east flanks of the Diablo and
Mendocino Ranges. Lower and Upper Cretaceous rocks are predomi-
nantly dark sandstone (graywacke) and arkose (granitic sandstone)
with minor shale and conglomerate. They contain larger proportions
of K-f eldspar grains than does the Franciscan.
Cenozoic formations comprise a great variety of sedimentary and
volcanic rocks but all are apparently of shallow marine (shelf and
slope) and continental origin. Rapid lateral changes in facies and
thicknesses reflect intermittent localized folding, faulting, and volcan-
jsm. Those changes are most marked at the margins of the basins
and ranges. Paleocene marine sedimentary rocks are quite similar to
those in Upper Cretaceous formations, but are not as thick or as -wide-
spread. Progressively more restricted seaways from Paleocene to late
Eocene time limited the deposition of Eocene sands, muds, and clays
to narrow basins in the area of the Coast Ranges.
From late Eocene to middle Miocene time, seaways in the Coast
Range region were severely restricted and climates became markedly
seasonal and locally semi-arid. Conglomerate, sandstone, shale, and
mudstone of these epochs include shallow-marine materials and exten-
sively distributed, and locally thick continental red beds. Oligocene
formations crop out only in the southern Coast Range: probably the
northern Coast Range area was above sea level during Oligocene time.
In the Santa Cruz, Santa Lucia, and Diablo Ranges, shallow-water
marine sandstone, shale, some conglomerate, and local tuff beds repre-
38 MINERAL AND WATER RESOURCES OF CALIFORNIA
sent deposits in rather restricted embayments and channels. South-
ward from the San Francisco Bay area, the Oligocene strata become
more continental and in the southern end of the Coast Ranges are
entirely land-laid.
Lower and middle Miocene formations consist of marine, shelf-f acies
sandstone, conglomerate, shale, and mudstone which were deposited in
rather narrow basins extensively in the southern Coast Ranges and in
a narrow trough as far north as the central Mendocino Range in the
northern Coast Ranges. Middle Miocene seas were more widespread
than those of the early Miocene. Great volumes of volcanic materials
were extruded during middle Miocene time — tuff, breccia, agglomerate,
rhyolitic to andesitic flows, and plugs.
Shallow seas reached a maximum extent in early late Miocene time.
The most widespread Tertiary formation is the Monterey Formation
of middle to late Miocene age which is found throughout the Coast
Ranges as far north as Point Arena. All common lithologic types
are represented, but most characteristic are siliceous shale, chert, and
diatomaceous shale. The Miocene Epoch closed with deposition of
coarser sandy marine sedimentary f acies, such as the San Pablo, Santa
Margarita, and Sisquoc Fonnations in more restricted basins between
the rising Coast Ranges.
In Pliocene time, sands, muds, and some tuff were deposited in nar-
row, shallow marine embayments throughout the Coast Ranges as far
north as the Eureka Basin. Most of the formations appear too diin,
or were not deposited, in the anticlinal-crest areas, reflecting uplift
and folding of many of the individual Coast Ranges. Late Pliocene
and early Pleistocene time were marked by very restricted and thin
local marine beds in narrow basins, and a remarkably widespread and
locally thick series of conglomerate and gravel. Floods of gravel and
coarse sand deposited in the chaimels, deltas, and floodplains of
streams almost covered the site of the southern Coast Ranges and ex-
tended locally along the margms of the northern Coast Ranges. Vol-
canism was locally important, but did not compare with the great
middle Miocene volcanic epoch. Late Quaternary formations include
some coastal marine terrace deposits, bay muds, and beach sands, but
most are flat-lying alluvium and local lake deposits.
Formations of Tertiary age are the principal source and reservoir
rocks for petroleum and natural gas. Most of the petroleum products
have come from the southern Coast Ranges. Principal production
is from Miocene and Pliocene formations in the Santa Maria, Cuyama,
and Salinas basins, and from the eastern flanks of the Diablo and
Temblor ranges. Upper Miocene and lower Pliocene marine sedi-
mentary rocks provide nearly all of California's diatomite. Quat-
ernary deposits are supplying most of the State's needs for sand and
gravel. Salt (sodium chloride) , bromine, and magnesimn compounds
are now obtained in large quantities from the waters of San Fran-
cisco Bay and the Pacific Ocean at Moss Landing.
Three great north-northwest-trending fault zones dominate the
structural pattern of the Coast Ranges. The most westerly of these
is the Nacimiento-Sur fault zone which separates the western coastal
block of Franciscan basement rocks from the granitic block east of
that fault zone. This fault is probably essentially normal, with per-
MINERAL AND WATER RESOURCES OF CALIFORNIA 39
haps some strike-slip in a right lateral sense, but in its northerly
projection extends into the Siir Thrust zone. No earthquakes of his-
toric record seem to have originated in the Nacimiento-Sur fault zone.
The great San Andreas fault, striking obliquely across the Coast
Ranges and Coast Range structures from the coast at Point Arena to
the Tehachapi Mountains 400 miles southeast is California's best-
known structural feature. South of the Tehachapi Mountains, the
fault zone extends along the east side of the Salton Sea. It extends
northward, offshore, probably at least as far as the Mendocino Escarp-
ment. Like the Nacimiento fault zone, the San Andreas separates
Franciscan basement on the east from the granitic basement. Move-
ments on tlie San Andreas fault during the Quaternary have been
right slip and normal; older displacements, probably beginning in
Late Jurassic time, which formed the Franciscan-granitic rock contact,
were perhaps predominantly vertical. Geologists are strongly divided
on this latter point, however; some maintain that there has been a
cumulative right slip of several hundred miles. The San Andreas
fault dips very steeply east and is essentially straight in strike except
at its southerly end and where it turns eastward as it enters the Trans-
verse Ranges province. Prominent branches of the San Andreas fault -
are the Pilarcitos, Hay ward, and Calaveras faults in the San Francisco
Bay area. The Pilarcitos is an older, inactive fault, but the others
have been the sources of a great many of California's earthquakes.
A third great fault zone, possibly related to the Nacimiento and San
Andreas in origin, is the South Fork Mountain fault which separates
the Franciscan block on the west from the Mesozoic granitic (and
older crystalline rock) block on the east. This great fault zone con-
stitutes the geologic and structural boundary between the Coast
Ranges and the Klamath Mountains provinces. The major contact
between Sierran granitic "basement" and Franciscan Formation of
the Coast Ranges, which lies buried beneath sediments of the west side
of the Great Valley, may be a southward continuation of the South
Fork Mountain fault. This is an old, inactive fault.
Apparently of major importance in the structural picture are
elongate masses of peridotite and the serpentine derived from it; they
are essentially sill-like bodies which seem to have intruded rocks as
young as Late Cretaceous in age. Because of the extreme mobility
of serpentine, such bodies are almost eveiywhere in fault contact with
other rock formations and are most commonly aligned along fault
zones. They commonly appear as "cold intrusions" faulted against
later rocks. Together with rocks of the Franciscan Formation, they
form a series of diapiric structures or piercements along the anticlinal
crest of the Diablo Range.
Folding of the Coast Ranges, like the accompanying faulting, has
been complex, and individual fold axes can seldom be traced more
than a few miles. Axial trends are generally parallel to the major
faults and thus tend to strike a little more westerly than the trend of
the Coast Ranges as a whole. Very little is known of structures within
the complex Sur Series and of how these rocks responded to the forces
which built the Coast Ranges. History of deformation within the
Franciscan Formation is also little known because of the complex
lithology, the discontinuity of individual lithologic units, and the
40 MINERAL AND WATER RESOURCES OF CALIFORNIA
massive character of the gray wacke which comprises such a large part
of the Franciscan. General heterogeneity of structure within the
Franciscan Formation is in striking contrast to the more open folding
of the shelf-and-slope sedimentary facies of approximately equivalent
ages. Major faults in the Coast Ranges are much more continuous
than the folded structures. Fold axes do not commonly continue from
one range into the next.
The Coast Ranges are flanked on the east by many thousands of
feet of Upper Jurassic, Cretaceous, and Cenozoic shelf- facies sedi-
mentary rocks which dip homoclinally toward the Great Valley from
the north end of the Sacramento Valley to the south end of the Diablo
Range. This thick group of shelf- facies rocks is separated from the
heterogeneously structured, eugeosynclinal Franciscan rocks on the
west by a major fault zone marked by sill-like bodies of serpentine.
The Coast Ranges were formed essentially by contemporaneous
folding, faulting, and uplift, probably beginning in Late Jurassic
time, and occurring again and again with increasing intensity to culmi-
nate in the mid-Pleistocene. Local uplift and depression, fault move-
ments, and mild folding have continued to the present.
Selected Refebences
Bailey, E. H., Irwin, W. P., and Jones, D. L., 1965, Franciscan and related rocks,
and their significance in the geology of western California : California Div.
Mines and Geology Bull. 183, 177 p.
Bowen, O. E., Editor, 1962, Geologic guide to the gas and oil fields of northern
California : California Div. Mines and Geology, Bull. 181, 412 p.
California Division Mines, 1951, Geologic guidebook of the San Francisco Bay
counties — history, landscape, geology, fossils, minerals, industry, and routes
to travel ; Bull. 154, 392 p.
California Division Mines and Geology, Geologic map of California, scale
1 : 250,000; sheets covering parts of Coast Ranges include Weed (1964), Red-
ding (1962), Ukiah (1960), Santa Rosa (1963), San Francisco (1961), San
Jose (in preparation 1965), Santa Cruz (1959), Fresno (in preparation 1965).
San Luis Obispo (1959), Bakersfield (1965), Santa Maria (1959), and Los
Angeles (in preparation 1965).
California Division Oil and Gas, 1962. California oil and gas fields — maps and
data sheets: Part I, San Joaquin-Sacramento valleys and northern coastal
regions, p. 1-493; Part II, Los Angele.s-Ventura basins and central coastal
regions, p. 495-913.
Hinds, N. E. A., 1952, Evolution of the California landscape: California Div.
Mines Bull. 158, p. 157-181.
Oakeshott. G. B., Editor, 1959, San Francisco earthquakes of March 1957 : Cali-
fornia Div. Mines Spec. Rept. 57, 127 p.
Taliaferro, N. L., 1943, Geologic history and structure of the central Coast Ranges
of California : California Div. Mines Bull. 118, p. 119-163.
GEOLOGY OF THE KLAMATH MOUNTAINS
(By W. P. Irwin, U.S. Geological Survey, Menlo Park, Calif.)
The Klamath Mountains are made up of rocks that for the most part-
are older and more highly defonned than those of surrounding prov-
inces. These older rocks, some of which are metamorphosed, are sedi-
mentaiy and volcanic in origin. Their principal deformation was dur-
ing the Nevadan (Jurassic) orogeny, during which they were intruded
by ultramafic and granitic rocks. These rocks, including the intni-
MINERAL AND WATER RESOURCES OF CALIFORNIA 41
sives, form a complex foundation, or subjacent terrane, on which
younger less deformed sedimentary and volcanic rocks are deposited.
The subjacent terrane of the Klamath Mountains is comparable to that
of the Sierra Nevada, and the two doubtless join beneath a cover of
superjacent rocks at the northeni end of the Great Valley (pi. 1) .
The sedimentary subjacent rocks are chiefly slaty shales, sandstones,
and conglomerate, but locally include discontinuous lenses of limestone
and thin-bedded chert. Volcanic rocks, most of which are basaltic or
andesitic, but some of which are rhyolitic, occur at irregular intervals
throughout the stratigraphic section of subjacent rocks. Tlie most
complete succession of subjacent strata is in the eastern part of the
Klamath Mountains, where the stratigraphic section is 40,000 to 50,000
feet thick and ranges from Late Ordovician to Middle Jurassic in age
(fig. 3). The economically most important of these are the Balaklala
Rhyolite (Devonian) and Bully Hill Rhyolite (Triassic) for their
copper deposits, the Bragdon Formation (Mississippian) for its gold-
bearing quartz veins, and the McCloud Limestone (Permian) quarried
for the manufacture of cement. In the western Klamaths, where the
geology is more complex and not as thoroughly studied, the strata
range from Devonian ( ? ) to Late Jurassic in age. These are separated
from the better known strata in the eastern Klamaths by an arcuate
belt of metamorphic rocks that is concave to the east (pi. 1). The
metamorphic belt includes homblendic and micaceous schists that were
formed from volcanic and sedimentary rocks during the Carboniferous
or earlier.
The subjacent strata were deposited mainly in the ocean along the
border of the ancient continent ; perhaps some of the volcanics formed
small islands and the limestones formed shallow reefs. This general
environment of deposition likely existed essentially until the Nevadan
orogeny, although there are gaps in the stratigraphic record as well as
evidence of tectonic activity earlier, but perhaps less intense than the
Nevadan. During the Nevadan orogeny, the thick, orderly succession
of strata were folded, faulted, and intruded by ultramafic and granitic
rocks. This orogeny culminated in the Late Jurassic with regional
emergence of the subjacent terrane above sea level.
The overall structure of the subjacent terrane, which presmnably
developed chiefly during the Nevadan orogeny, is not clearly known.
Most of the principal folds and faults trend parallel to the arcuate
lithic belts, as do many linear ultramafic bodies and certain of the
granitic intrusives (pi. 1). The arcuate pattern is intei-preted to re-
sult from westward thrusting along low-angle faults; ultramafic rock
has been intruded along some of the thrust faults. The ultramafic
rocks are important as a source of chrome ore.
With emergence of the Klamath Mountains, near the close of the
Jurassic, great quantities of debris were shed from the newly made
land into the bordering seas. Erosion proceeded so vigorously that,
by the Early Cretaceous, the cover was stripped from the once deeply
buried Nevadan batholithic rocks. The detritus from the eroded cover
was deposited as a thick section of strata m the bordering seas on the
upturned edges of the deformed subjacent strata and on the eroded
batholithic rocks.
Deposition of the marine superjacent strata continued during most
of the Cretaceous as the land area shrank owing to erosion and slow
67-164 o— «e^-pt. I- — -4
42 MINERAL AND WATER RESOURCES OF CALIFORNIA
submergence. Near the end of the Cretaceous, the Klamath reg:ion
again rose above sea level, and although it is clear that the Cretaceous
superjacent deposits once covered much of the Klamath region, only a
few small patches now remain to be seen. The end of the Cretaceous
marked the last significant marine invasion of the Klamath region.
During the Tertiary, the Klamath Mountains province continued to
undergo erosion and was the source of detritus for marine and conti-
nental strata now exposed around much of its perimeter in Oregon and
along its eastern side in California. Within the province, the Tertiary
is represented chiefly by the continental Weaverville Formation of
probable Oligocene age (fig. 3). The Weaverville Formation crops
out in several structurally controlled, northeast-trending patches in the
southern part of the province, and lies un conformably on Cre-
taceous and older rocks. It consists of beds of locally derived sand-
stone, mudstone, conglomerate, tuff, and lignite that probably were de-
posited on flood plains and in swampy lakes. In the extreme western
part of the province a few small, thin patches of essentially horizontal
beds of friable detrital rocks are found on the crests of ridges. These
rocks, called the Wimer Beds, contain marine fossils of late Miocene
age.
The crests of the ridges, on which the remnants of the Wimer Beds
are found, are similar in altitude to the crests of other ridges nearby.
This accordance of crestlines led to the idea that many of these broad-
topped ridges are remnants of an ancient land surface of low relief,
named the Klamath peneplain. Crestlines equated with this hypo-
thetical erosion surface are widespread in the Klamath Mountains and
increase in altitude from about 2,500 feet in central Del Norte County
to more than 6,000 feet in southern Trinity County. A succeeding
cycle of erosion, the Sherwood stage, destroyed much of the so-called
Klamath peneplain and developed broad land surfaces at lower alti-
tudes between the remnants. The Sherwood surface has in turn been
dissected deeply by modern streams, giving rise to a second set of ac-
cordant ridges.
Volcanic rocks that range from basalt to rhyolite in composition
erupted extensively along the eastern edge of the Klamath Mountains
during the Cenozoic Era. They are the principal rocks of the Cas-
cades province and are prominent in the northern part of the Great
Valley. Within the limits of the Klamath Mountains these volcanic
rocks occur as thin erosional outliers that at some places have over-
lapped the boundary between the subjacent terrane and the Cretaceous
superjacent rocks. The oldest of these is the Tuscan Formation of
Pliocene age, which consists of clastic volcanic rocks interlayered with
sands and gravels.
Weakly consolidated Pleistocene gravels of the Eed Bluff Formation
are widespread in the northern part of the Great Valley and lap onto
the southeastern edge of the Klamath Mountains. Within the Klam-
ath Mountains, sands and gravels are found on terraces at many levels
along the courses of the major streams, and some of the higher of these
may be equivalents of the Red Bluff Formation. Many of these ter-
race deposits, as well as the sands and gravels in the present drainage
channels, have been an important source of placer gold.
MINERAL AND WATER RESOURCES OF CALIFORNIA 43
Selected References
Albers, J. P., and Robertson, J. F., 1961, Geology and ore deposits of Blast Shasta
copper-zinc district, Shasta County, California : U.S. Geol. Survey Prof. Paper
338, 107 p.
Davis, G. A., and Lipman, P. W., 1962, Revised structural sequence of pre-
Cretaceous metamorphic rocks in the southern Klamath Mountains, California :
Geol. Soc. America Bull., v. 73, no. 12, p. 1547-1552.
Diller, J. S., 1906, Description of the Redding quadrangle [California] : U.S. Geol.
Survey Atlas, Folio 138, 14 p.
Irwin, W. P., 1960, Geologic reconnaissance of the northern Coast Ranges and
Klamath Mountains, Clalifomia : California Div. Mines Bull. 179, 80 p.
, 1964, Late Mesozoic orogenies in the ultramafic belts of northwestern
California and souithwestern Oregon: U.S. Geol. Survey Prof. Paper 501-O,
p. C1^9.
Kinkel, A. R., Jr., Hall, W. E., and Albers, J. P., 1956, Grcology and base-metal
dei)osits of West Shasta copper-zinc district, Shasta County, California : U.S.
Geol. Survey Prof. Paper 285, 156 p.
Sanborn, A. F., 1960, Geology and paleontology of the Big Bend quadrangle,
Shasta County, Oalifomia : California Div. Mines Spec. Rept. 63, 26 p.
Wells, F. G., Walker, G. W., and Merriam, C. M., 1959, Upper OrdoviCian( ?) and
Upper Silurian formations of the northern Klamath Mountains, California :
Geol. Soc. America Bull., v. 70, no. 5, p. 645-649.
GEOLOGY OF THE SOUTHERN CASCADE RANGE, MODOC PLATEAU,
AND GREAT BASIN AREAS IN NORTHEASTERN CALIFORNIA
(By G. A. Macdonald, U.S. Geological Survey, Hawaii Institute of Geophysics,
Honolulu, Hawaii ; and T. E. Gay, Jr., California Division of Mines and
Geology, San Francisco, Calif. )
The Cascade Range, Modoc Plateau, and Great Basin geomorpliic
provinces in northeastern California are discussed together in this sec-
tion because their general lithologic and structural continuities are
more notable than their dissimilarities.
Southern Cascade Range
The Cascade Range is a volcanic mountain range that extends south-
ward into California from Oregon and Washington. In Oregon and
northernmost California, the oldest rocks of the range — the Western
Cascade series— are Miocene in age and rest on marine and nonmarine
sedimentary rocks of Eocene and Oligocene age. The Western Cascade
rocks consists of lava flows of basaltic, andesitic, and dacitic composi-
tion, with intercalated pyroclastic rocks, some of which are rhyolitic.
They are characterized by a general alteration of ferromagnesian mm-
erals to chlorite and related minerals, which gives a slight greenish
coloration to the rocks. Tlie alteration is probably the result of a
general permeation by hydrothermal solutions near the end of the
Miocene Epoch, when the rocks were somewhat uplifted by mountain-
building movements. In Oregon, the rocks were invaded by small
Tertiary granitoid intrusions which brought some deposition of metal-
lic ores. In California, however, these intrusions are not exposed, and
no economic metallization has yet been found in the Western Cascade
rocks of this State.
As their name implies, the Western Cascade rocks are exposed in a
north-south belt along the w^esteni side of the Cascade Range. In
California, this belt is about 5 to 15 miles wide and extends about 50
44 MINERAL AND WATER RESOURCES OF CALIFORNIA
miles south of the Oregon border. The southernmost exposures of the
rocks are just southwest of the toAvn of Mount Shasta.
After the Western Cascade rocks were eroded for an interval in late
Miocene to early Pliocene time, volcanic activity resumed in the early
Pliocene. A new series of rocks, the High Cascade series, was erupted
to form a ridge overlapping and parallel to the Western Cascade series
but slightly farther east — a belt about 30 to 40 miles wide and 150 miles
long in California.
The High Cascade rocks range from basalt to rhyolite, with py-
roxene andesite predominating. The High Cascade volcanism resulted
in an extension of the Cascade Range some 80 miles southeast of the
Western Cascade belt, beyond Mount Lassen, to Lake Almanor. At
the soutlieast end of the Higli Cascade belt, its lavas overlap the
metamorphic and granitic rocks of the Sierra Nevada along an irregu-
lar line that runs in general southwestward from near Susanville past
Lake Almanor toward Oroville. The oldest of the Pliocene High Cas-
cade rocks in California are near the southeast end of the raiige. Li
the region just southwest of Lassen National Park, High Cascade
andesite flows are overlain by the late Pliocene Tuscan Formation.
The latter consists largely of volcanic breccias deposited as mudflows,
grading westward into volcanic conglomerates and sandstones, and
spreading far southward over the western edge of the Sierra Nevada.
Interbedded with the Tuscan breccias near their base is the rhyodacitic
Nomlaki Tuff Member, formed by incandescent flows of volcanic ash
that were still so hot when they came to rest that the particles of glass
became welded together in the middle and lower parts of the layer.
In the area east of Redding, Cascade lavas are absent beneath the
Tuscan Formation, which there rests directly on sedimentary rocks of
Eocene and Late Cretaceous age. The Eocene rocks consist of con-
glomerate and sandstone of the nonmarine Montgomery Creek Forma-
tion, containing fossil leaves, petrified wood, and some beds of low-
grade coal. The Late Cretaceous rocks are sandstones and shales,
which elsewhere contain some petroleum, but so far none has been
found in this area.
Tlie early High Cascade lavas were very fluid basalt and basaltic
andesite that erupted quietly, with very little explosion. They erupted
from fissures and built a broad ridge of overlapping, low shield vol-
canoes and lava flows. As time passed, some of the erupting lava
became more silicic, and the amount of explosive activity increased.
Big composite cones of interbedded andesitic lava flows and pyroclastic
debris were built along the cres't of the ridge, with associated domes
and flows of dacite, and, toward its southern end, rhyolite. The big
cones included Mount Shasta; Burney Mountain; Crater (Magee)
Peak; a mountain known as Mount Tehama, or Brokeoff Volcano,
that once occupied the vicinity of the present Lassen Peak; and an-
other that once stood just to the southwest, in the area of Mineral.
On the flanks of the latter, huge flows of rhyolite lava and ash were
erupted, and probably as a result of the draining of this magma from
beneath, the top of the mountain collapsed to form a caldera like the
well-known caldera of Crater Lake in Oregon. The summit of
Brokeoff Volcano also caved in to form a caldera, within which con-
tinued volcanism built a series of dacite domes, including Lassen Peak.
MINERAL AND WATER RESOURCES OF CALIFORNIA 45
Just nortli of the great dome of Lassen Peak a row of similar domes,
the Chaos Crags, grew in very recent time. Explosions at their base
undermined the north edge of the domes, which collapsed in a series
of avalanches to form the Chaos Jumbles. About the same time a flow
of incandescent ash swept down the valley of Manzanita Creek from
the northwest side of Lassen Peak. The last of the avalanches and
the ash flows occurred only about 200 years ago. Mount Lassen erupted
most recently during the summers of 1914-1917, with a small flow of
lava at the summit ot the dome, and mudflows and a glowing avalanche
to the northeast, down the valleys of Lost and Hat Creeks.
Momit Shasta, the largest of the Cascade Range volcanoes, rises
10,000 feet above its base and has a volume of about 80 cubic miles.
The main cone consists at the base largely of flows of basaltic andesite,
and in its upper part predominantly of flows of pyroxene andesite with
a smaller proportion of dacite. Pyroclastic materials and mudflow
deposits are spai^se. After the main cone had formed, a north-south
fissure across it controlled the emplacement of a later series of donies,
cinder cones, and associated lava flows, ranging from basalt to dacite.
During late Pleistocene time, flows of basaltic andesite extended more
than 40 miles southward along the Sacramento River Canyon from
Everitt Hill, a small shield volcano on the southwest flank of Mount
Shasta. At Shasta Springs a large volume of water issues from the
base of these flows. Also in the waning stages of the volcano, an east-
west fissure on its western flank resulted in the lateral cone of Shastina,
and the dome of Black Butte at the western base of the moimtain.
Postglacial lava flows from vents below Shastina, and two small domes
that grew in the crater of Shastina, escaped erosion by the glaciers that
covered most of Mount SKasta and Shastina during the Pleistocene
epoch.
The latest eruptions of Shasta, possibly as recent as 1786, formed a
blanket of pumice and cinder over the top of the mountain. A small
acid hot spring still exists at the edge of the snowfield that fills the
summit crater. Although there is no sign that they are imminent,
future eruptions of Shasta, Lassen, and other Cascade volcanoes, are
not only possible, but probable.
The Medicine Lake Highland, some 35 miles east of Mount Shasta,
is generally regarded as an outlier of the Cascade Range. The region
is underlain by the Oligocene to Miocene Cedarville Series and the
Pliocene Warner Basalt, both of which are widespread in the Modoc
Plateau, to the east. The building of the Highland was preceded, in
early Pliocene time, by eruption of flows and domes of rhyolite and
rhyolitic obsidian and a flow of incandescent ash, and farther w^est by
the building of a series of cones of massive basalt flows. Then, in
late Pliocene and early Pleistocene time, a shield volcano 20 miles
across was formed, of pyroxene andesite. After reaching a height of
about 2,500 feet, the top of the shield collapsed to form a caldera 6
miles long, -4 miles wide, and 500 feet deep. Lava rising along the cir-
cular fractures that bomided the caldera formed flows that poured into
it, building cones that eventually overtopped its rim and sent new
flows down the outside of the shield. The resulting eight small vol-
canoes completely hide the caldera boundaries, forming between them
the basin that holds Medicine Lake. Later Pliocene and Pleistocene
46 MINERAL AND WATER RESOURCES OF CALIFORNIA
eruptions of andesite, dacite, and rhyolite built broad ridges north
and south of the laJie basin, including the perlitic rhyolite mass of
Mount Hoffmann, flows of glassy dacite just north of Medicine Lake
and on the south side of Mount Hoffman, and finally — about 1700
years ago — the obsidian masses of Little Glass Momitain and Glass
Moimtain. Transition of the Medicine Lake Highland to the Modoc
Plateau is marked by Recent basalt flows and cinder cones of types
widespread in the Plateau, on the flanks of the Highland.
Modoc Plateau
The Modoc Plateau is a highland region capped by vast late Tertiary
and Quaternary basalt plains and numerous volcanic shield cones that
largely overlap older basin-range structures. These structures are
typified by fault-block mountains of Tertiary volcanic rock, wnth inter-
vening basin-like grabens that commonly contain sedimentary rocks
deposited in large Pliocene and Quaternary lakes that had resulted
from interruption of the drainage by faulting or volcanism. To the
east and southeast the Modoc Plateau merges w^ith the Great Basin,
across an arbitrary boundary. The Warner Range, which borders the
Modoc Plateau on the east, is generally regarded as a part, of the Great
Basin, but its rocks and general structure are continuous with those of
the Modoc region. On the west, the border of the Modoc Plateau with
the Cascade Range is also indefinite; the faulting characteristic of the
Modoc region extends into the edge of the Cascade Range, and some
types of rocks arci conunon to both provinces.
The oldest rocks of the Modoc region are a series of interbedded lava
flows, pyroolastic rocks, and lake deposits forming some of the block-
faulted ranges, and generally tilted at an angle greater than 20°.
Through similar lithology and structiu'al relationships, they are cor-
related with the Cedarville Series, which is best exposed in the Warner
Range, w^here it ranges in age from late Oligocene to late Miocene.
The Cedarville Series is mainly andestitic, but ranges from basalt to
rhyolite. Several small gold, copper, and mercury deposits have been
fomid in rocks associated with it.
Rocks of Pliocene age include both volcanic and lake deposits. The
latter include the Alturas Formation, which occupies the basin west of
the Wanier Range in the vicinity of Alturas, and similar rocks in the
basin of Lake Britton and the valley of Willow Creek west of Tulelake.
The lake sediments are tuffaceous siltstones and ashy sandstones — the
latter commonly ranging to current- bedded, water-laid tuffs — and
thick, extensive deposits of diatomite with variable ash content. The
Pliocene volcanic rocks include basalt and andesite lava flows and mud
flows, and dacitic to rhyolitic pyroclastic rocks. Southwest and west
of Alturas, the Alturas Formation is locally associated with beds of
pumiceous welded tuff, fonmed by incandescent flows of ash ; the tuff
has been quarried to a minor extent for buildmg stone. Similar but
less- welded Pliocene ash-flow deposits are also present in the momitains
between Canby and Adin, where they are interbedded with lava flows
and mud-flow deposits, as well as stream- and lake-deposited sediments.
The older Pliocene rocks, like those of Miocene age, are found in
block-faulted mountain ranges. Later volcanic rocks, also tentatively
assigned to the Pliocene, are much less faulted and retain to a much
MINERAL AND WATER RESOURCES OF CALIFORNIA 47
greater degree their original constructional land forms. These include
a series of small shield volcanoes between Honey Lake and the Madeline
Plains.
Throughout much of the Modoc Plateau region the basins between
the fault-block ranges were flooded by wide-spreading, very fluid flows
of basalt, erupted mostly from fissure vents, that formed flat plain
surfaces rather than volcanic cones. These "plateau" basalts have
generally been i-eferred to as "Warner Basalt," but because of uncer-
tainty of the correlation with the basalt farther northeast, the basalt
in the region just north of Lassen National Park has been called the
Burney Basalt. At the north edge of Lake Britton, pillow lavas at
the base of the Warner Basalt are intermingled with Pliocene diato-
maceous lake sediments, and are almost surely of Pliocene age; but
near Lassen Park the Burney Basalt overlaps folded and eroded
andesites that cannot be older than latest Pliocene, and it is therefore
milikely that the basalt is older than earliest Pleistocene. In the
Modoc Plateau region as a whole, the rocks called Warner Basalt
probably range from late Pliocene to Pleistocene in age.
Younger than the Warner Basalt is a series of lower Pleistocene to
Recent basalt flows and associated cinder cones ; small shield volcanoes,
many of them capped with cinder cones; and lake beds. The lake
sediments resemble those of Pliocene age. Tlie shield volcanoes are
mostly basalt, but partly andesite. Chemically, mineralogically, and
texturally, many of these flow basalts resemble the Warner Basalt.
Many of them are of pahoehoe type, like most of the Warner flows,
and in places contain many lava tubes such as those of the Lava Beds
National Monument and Hat Creek Valley, where the lavas are
probably less than 2000 years old.
Other very recent flows are of the aa or block lava type. These in-
clude the Callahan and Burnt Lava flows on the flanks of the Medicine
Lake Highland, and the quartz basalt flows at Cinder Cone in the
northeastern part of Lassen National Park, which last erupted in 1851.
The faults of the Modoc region trend in a northwesterly to north-
erly direction. The Likely fault is believed to have had appreciable
right-lateral movement, but most of the faults are normal, with pri-
marily vertical displacement. The normal faulting reached a maxi-
mum near the end of the Miocene, but has continued into Recent time.
Occasional earthquakes suggest that some of the faults, such as that
along the east side of Hat Creek Valley, are still active.
Large volumes of water issue from the Warner and later basalts
at several places, including Big Spring, near Old Station on Hat
Creek ; Rising River, farther north in the same valley ; the springs at
Burney Falls and along Burney Creek just above the falls; and those
at the headwaters of Fall River. The latter, with a flow of about 900
million gallons daily, are among the largest springs in the United
States.
Great Basin
Two minor projections of the Great Basin province — the Warner
Range-Surprise Valley area, and Honey Lake Valley — adjoin the
Modoc Plateau and the Sierra Nevada provinces in northeastern Cali-
fornia. Their dominant northeast-trending block-faulted structure
48 MINERAL AND WATER RESOURCES OF CALIFORNIA
is characteristic of the Great Basin province, but their rocks are re-
lated to adjacent provinces rather than to those of the Great Basin.
The Warner Range is uplifted at least 5,500 feet vertically, west of
the Surprise Valley normal fault, and consists mainly of andesitic
to basaltic flows and pyroclastic rocks of the Oligocene to Miocene
Cedarville series. Flows of Pliocene to Pleistocene "Warner Basalt"
cover the gentler sloping south^vest flank of the range, and w^th the
coalescing Miocene and Pliocene shield volcanoes that form its south-
ern end, are transitional from the Great Basin to the Modoc Plateau.
Toward the Oregon border, the range has a steeper, faulted western
front, lapped with Quaternary gravels that probably represent accel-
erated erosion and transport in glacial times. Intrusive masses of post-
Cedarville rhyolitic rocks in the northern part of the range include
the gold veins of the High Grade district, the quicksilver showings
along the Goose Lake front of the range, and notable deposits of
obsidian and perlite.
Surprise Valley, the near- desiccated site of Pleistocene Lake Sur-
prise— contemporary of Lake Lahontan, wiiich was only 35 miles to the
south — is a graben east of the spectacular Surprise Valley fault scarp.
Numerous hot springs and the eruption of a mud volcano in 1955 sug-
gest recency of fault movement and continued connection with under-
lying thermal zones.
Honey Lake Valley is a graben wedged between the northern end
of the Sierra Nevada granitic mountains, and the southern end of the
Modoc Plateau volcanic terrane. Spectacular faults form the Sierra
front and bound the Fort Sage Mountains block at the southeast end
of the Valley. Steeply tilted and folded Tertiary lake sediments at
the southeast end of Honey Lake are almost concealed by Recent lake
and alluvial cover. Tufa-building hot springs along the northeast
edge of the valley, some with traces of quicksilver, suggest hidden ex-
tensions of province-bounding faults.
GEOLOGY OF THE GREAT VALLEY
(By C. A. Bepenning, D. L. Jones, and W. O. Addicott, U.S. Geological Survey,
Menlo Park, Calif. )
The Great Valley of California is an elongate northwest-trending
structural trough formed by the westward tilting of the Sierra Nevada
block against the eastern flank of the Coast Ranges. In general, sed-
iments deposited in this trough dip uniformly westward away from
the Sierra Nevada except in a belt along the southern and western
sides of the Great Valley where deposition was greatest and where
deposits generally dip to the east. Tlie Coast Ranges have not devel-
oped in as structurally uniform a way as has the Sierra Nevada and
the western limit of the Great Valley depositional basin was poorly
defined in pre-Tertiary time. In early Tertiary time, however, evolu-
tion of the Coast Ranges progressed to the point where the western
limits of the Great Valley depositional basin were in large part co-
incident with those of the modern geomorphic province.
In this great trench the accumulation of sediments may locally have
reached a thickness of 6 miles in the San Joaquin Valley and 10 miles
MINERAL AND WATER RESOURCES OF CALIFORNIA 49
in the Sacramento Valley. Most of the deposits in the Sacramento
Valley are composed of Upper Jurassic and Cretaceous sandstone and
siltstone of marine origin. The deposits in tlj£LSaiL JoaquinJValley by
contrast, are_largeIyJlce_taceojLS_|indJCerfciary marine sandstone, silt-
stone, and claystone with an increasing proportion of continental
deposits in younger strata. The consequent fticies variations in the
Tertiary deposits of the San Joaquin Valley have led to a complex
stratigraphic nomenclature and have provided a wide variety of
stratigraphic traps for the accumulation of petroleum.
Pre-Tertiary Rocks
Clastic upper Mesozoic rocks, ranging in age from Late Jurassic to
Late Cretaceous, form an enonnously thick wedge that thickens from
a few hundred f eeft on the east to over 40,000 feet on the west. The
rocks on the eastern side are dominantly shallow Avater marine, with
perhaps some minor brackish water or nonmarine beds present, and
on the western side are dominantly deep water, marine turbidites. Tlie
present western margin of these rocks is a major fault marked by
extensive intrusion of serpentine that separates the structurally simple,
eastward-dipping rocks of the Great Valley from the structurally
complex and partly metamorphosed upper Mesozoic rocks of the Coast
Ranges.
Upper Jurassic rocks are thickest along the western edge of the
Sacramento Valley where they comprise about 15,000 feet of
dominantly dark gray fine- to coarse-grained clastic sediments.
Marine volcanic rocks are locally present in the lower part of the
sequence.
In the San Joaqum Valley, Upper Jurassic rocks are much thinner
than in the Sacramento Valley, and range in thickness from a few
hundred feet to perhaps several thousand feet. The dominant rock
type is bluish-gray siltstone and shale with fossiliferous, light gray-
weathering limestone concretions.
Lower Cretaceous rocks are thickest and most widespread on the
western side of the Sacramento Valley where they comprise 15 to 20
thousand feet of alternating thick units of mudstone, sandstone, and
conglomerate. Facies changes along strike are common, and there
is complex intertonguing and lensing-out of sandstone and conglom-
erate beds.
In the San Joaquin Valley, a very thm sequence of lowermost
Cretaceous rocks apparently rests conformably on Upper Jurassic
rocks, and this, in turn, is overlain directly in many places by thick
Upper Cretaceous rocks. In a few places, beds of late Early Cretace-
ous (Albian) age crop out, but their distribution and relationship are
poorly understood. Apparently much of the San Joaquin Valley
region either received little or no sediment during most of Early
Cretaceous time, or the rocks were removed by erosion prior to deposi-
tion of Upper Cretaceous beds.
Upper Cretaceous rocks are widespread on both the east and west
sides of the Great Valley and consist of alternating thick units of
sandstone, mudstone, and locally thick conglomerate lenses. In the
southern and central part of the western Sacramento Valley, each
50 MINERAL AND WATER RESOURCES OF CALIFORNIA
sandstone and mudstone imit has received a formational name as
shown on the correlation chart, but these units become unreco^izable
to the north. On the east side of the Sacramento Valley, a few thou-
sand feet of fossiliferous sandstone, shale, and conglomerate are ex-
posed in the valleys of the major rivers. Near Chico these deposits
have been named the Chico Formation.
Uppermost Cretaceous rocks which occur only in the subsurface in
the southern and central parts of the Sacramento Valley contain large
reserves of gas. The principal Cretaceous producing horizons are the
Forbes Formation, Kione Formation or Sand, and Starkey Sand.
Upper Cretaceous rocks of the San Joaquin Valley are generally
subdivided into the Panoche Group or Formation and the overlying
Moreno Formation or shale. The Panoche Group comprises over
20,000 feet of alternating thick units of shale, sandstone, and conglom-
erate that exhibit rapid f acies changes along strike.
The Moreno Formation consists of about 3,000 feet of purple and
maroon claystone with minor beds of sandstone and white porcellan-
ite. Organic remains, mainly fish scales, foraminifera, and diatomite,
are common, as is pyrite in the subsurface and gypsimi at the surface.
Deposition probably took place in a restricted basin with stagnant
conditions near the bottom. The uppermost part of the Moreno
Formation is of earliest Tertiary age.
Significant natural gas production from sandstone reservoirs in the
Panoche and Moreno is developed in several fields in the northern
part of the San Joaquin Valley, principally in the vicinity of Stockton.
Tertiary Rocks
In contrast to pre- Tertiary deposition, Tertiary deposition took
place in more limited basins which more nearly approximate the
modern boundaries of the province. Three structural developments
restricted the Tertiary depositional basins: evolution of the Coast
Ranges progressively limited the westward continuity of depositional
basins with the Pacific; proportionately greater westward tiltmg of
the southern part of the Sierra Nevada block accentuated basining
in the San Joaquin Valley area so that marine basins gradually with-
drew southward from the Sacramento Valley ; and a prominent arch,
the Stockton arch, united the Sierra Nevada with the Coast. Ranges
and disintegrated the continuity of the marine depositional basins
within the Great Valley province (fig. 4) .
Paleocene and early Eocene marine deposits were formed in the
southern part of the Sacramento Valley. This sequence includes the
Martinez and Meganos Fonnations, important gas producing units.
The overlying Capay Formation is a widespread transgressive unit
that unconformably oversteps lower Tertiary and Upper Cretaceous
rocks towards the north and the east in the subsurface. These for-
mations are composed of dark gray, green, and brown siltstone, sand-
stone, and conglomerate with locally abundant glauconite. Scattered
continental deposits of probable Paleocene or Eocene age occur in
the northern end and along the eastern side of the Sacramento Valley.
Two unusual subsurface features of early Eocene age are the Prince-
ton and Meganos Gorges of the central and southern parts of the
MINERAL AND WATER RESOURCES OF CALIFORNIA
51
EXPLANAT ION
Tertiary and Quaternary
I sedimentary rocks
I Pre-Tertiary rocks and
iTertiary volcanic rocks
\
Figure 4. Index map of Great Valley locating selected palegeograpMc features.
Sacramento Valley. These south- to southwest-trending submarine
erosional channels and their sedimentary fill are important in the en-
trapment of gas in west -dipping Cretaceous and lower Tertiary
sandstones.
Marine early Tertiary shale and minor sandstone included in the
Lodo Formation were deposited in a basin lying between the Stock-
ton arch and Bakersfield. One of several prominent Paleocene to
middle Eocene sandstone units along the western side of the basin,
the Tesla Formation, may have been deposited in a strait that crossed
the western end of the Stockton arch and united the Paleocene to
middle Eocene basins on either side. Part of the early Tertiary con-
tinental deposits along the east side of the San Joaquin Valley may be
equivalent in age to the Lodo.
52 MINERAL AND WATER RESOURCES OF CALIFORNIA
A widespread unconformity separates early Eocene from late Eo-
cene rocks south of the Stockton arch. On this erosion surface the
Domengine Sandstone and the Kreyenhagen Shale were deposited.
North of the arch a relatively thin blanket of sandstone, the lone
Formation, covers the east side of the south half of the Sacramento
Valley. Thick late Eocene deposits consisting of interbedded shale
and sandstone (Domengine?, Nortonville, and Markley Formations)
are present only in the southwestern part of the valley. Late Eocene
deposits are missing on the Stockton arch. In tJ^e San Joaquin Val-
ley the late Eocene marine basin extended southward to deposit the
thick Tejon Formation at the foot of the San Emigdio Mountains.
Continental sediments of apparent late Eocene age were deposited
along the foot of the Sierra Nevada.
Oligocene deposits were formed in essentially the same basms as the
late Eocene deposits. North of the Stockton arch a pronounced period
of erosion followed late Eocene deposition. In the southern part of
the Sacramento Valley a prominent south- to southwest-trending sub-
marine channel of latei Eocene to Oligocene age, the Markley Gorge,
was eroded into lower Tertiary strata and subsequently filled with
marine sand and siltstone. South of the arch, however. Eocene to
Oligocene deposition appears to have been continuous. Oligocene
sediments are donnnantly shale and are often jncludedjgith the under-
lying Kreyenhagen ^Kale. In tKe^outhem part of the San Joaquin
Valley, however, sandstone, partly of continental origin, is a prominent
part of the Oligocene section.
In early Miocene time no marine deposits were formed north of the
Stockton arch. South of the arch lower Miocene marine deposits in
the south half of the San Joaquin Valley consist of sandstones and
sandy shales including the Temblor Formation and the Vedder Sand.
Continental formations border these marine deposits on the south and
the southeast. A fairly thick sheet of continental deposits interfingers
with the marine section in the central part of the San Joaquin basin
and extends northward across the Stockton arch into the Sacramento
Valley. Extensive rhyolitic tuffs and other volcanic materials are
present in the continental lower and middle Miocene deposits of the
Sacramento Valley.
In middle Miocene time the areas of deposition remained essentially
the same but less marine sandstone was formed. Sand content in-
creased again during the late Miocene as the basin shoaled and the
shoreline began retreating towards the west. The Santa Margarita
Sandstone of the eastern part of the marine basin was overlain by
nonmarine Miocene- and Pliocene deposits including the Chanac For-
mation. To the west, in the deeper part of the basin from Coalinga
to the southern end of the valley, dominantly fine-grained diato-
maceous, cherty and siliceous sediments were deposited. Discontinuous
offshore sandstones in the southern part of the basin, such as the
Stevens Sand, form many oil-producing stratigraphic traps.
North of the Stockton arch, the sea gradually transgressed east-
ward from the San Pablo basin west of the Great Valley and by late
Miocene time extended into, the western part of the Sacramento Valley.
During the late Miocene and the Pliocene volcanic sediments being
deposited in the southeastern quarter of the Sacramento Valley
MINERAL AND WATER RESOURCES OF CALIFORNIA 53
changed composition from rhyolitic (Valley Springs Formation) to
andesitic (Mehrten Formation). The change from rhyolitic to ande-
sitic debris is also found in the marine conglomerates of the San Pablo
Group near the southwestern edge of the Sacramento Valley.
Tectonic activity in the Great Valley at the beginning of Pliocene
time resulted in erosion in many areas, particularly along the western
edge of the San Joaquin Valley. Many of the oil fields in this area
produce either from structural traps caused by the early Pliocene
warping or from truncated Miocene reservoir beds sealed by Pliocene
deposits. With few exceptions, the present boundaries of the Great
Valley were developed during the early Pliocene orogeny, and Pliocene
deposition, largely continental, took place in all parts of the valley.
Pliocfiiie-4iLarine deposition in the Great Valley was restricted to
the south half of the San Joaquin Valley. In the western part of the
area shallow water conglomerate, sandstone, and sandy shale of the
Jacalitos, Etchegoin, and San Joaquin Formations were deposited.
The basal Pliocene units unconformably overlie the upturned edges
of older rocks along the western and southern margins of the valley.
As Pliocene deposition continued the sea gradually retreated and
the thick wedge of continental deposits of the southeastern part of the
valley spread basinward. The nonmarine Chanac and Kern River
Forrnations of the southeastern San Joaquin Valley are continuous
Avith Pliocene continental deposits that cross the Stockton arch and
extend throughout the Sacramento Valley.
Pleistocene Eocks
Deposition in most parts of the Great Valley was continuous from
Pliocene to Pleistocene time. In the area of marine Pliocene deposi-
tion fresh-water lakes were formed at about the beginning of Pleis-
tocene time due to disintegration of the seaway between the Great
Valley and the Pacific by rising blocks of the Coast Ranges. Lacus-
trine sandy shale and sandstone of the Tulare Formation unconform-
ably overlie marine Pliocene rocks along the west side of the Valley.
These grade marginally into continental deposits.
Summary
During the later Mesozoic the Great Valley was the site of deposi-
tion of a great wedge of marine sedimentary rocks that reached
thicknesses of more than -1:0,000 feet along the west side. As deposition
continued the locus of maximum sedimentation gradually was dis-
placed southward from the northern part of the Great Valley to the
extreme south end by latest Tertiary time. Widespread Mesozoic
deposits of Late Cretaceous age gave way to much restricted deposi-
tional basins in the early Tertiary when the Great Valley became
separated by the cross- valley Stockton arch. Tertiary marine deposi-
tion in the southern part of the Sacramento Valley north of the
Stockton arch continued into the Oligocene after which the seas re-
treated to the San Pablo Basin, a small marginal basin to the south-
west. The initial locus of marine Tertiary deposition in the San
Joaquin Valley was centrally located adjacent to the Vallecitos Straits,
a persistent Paleocene to middle Miocene connection to the sea. Begin-
ning in late Eocene time, the locus of deposition shifted toward the
54 MINERAL AND WATER RESOURCES OF CALIFORNIA
south end of the Valley and an additional marine connection opened
along the southwest side of the Valley. Upper Eocene and later
sedimentary deposits were localized in sub-basms created by a cross-
valley submarine ridge, the Bakersfield arch. Marine deposition ceased
at the close of the Pliocene.
Selected References
Payne, M. B., 1960, Type Panoche, Panoche Hills, Fresno County, California :
Soe. Ek?on. Paleontologists and Mineralogists, Pacific Section, Guidebook 1960
Spring Field Trip, 12 p.
Reed, R. D., 1933, Geology of California : Tulsa, Oklahoma, Am. Assoc. Petroleum
Geologists, 355 p.
Repenning, C. A., 1960, Geologic summary of the central valley of California with
reference to the disposal of liquid radioactive waste : U.S. Geol. Survey Trace
Elements Invest. Rept. 769, 69 p.
Safonov, Anatole, 1962, The challenge of the Sacramento Valley, California :
in Bowen, O. E., Jr., ed.. Geologic guide to the gas and oil fields of northern
California : California Div. Mines Bull. 181, p. 74-97.
Woodring, W. P., Stewart, Ralph, and Richards, R. W., ItKlO, Geology of the
Kettleman Hills oil fields, California : U.S. Geol. Survey Prof. Paper 195, 170 p.
GEOLOGY OF THE SIERRA NEVADA
(By P. C. Bateman, U.S. Geological Survey, Menlo Park, Calif.)
The Sierra Nevada is a strongly asymmetric mountain range — it has
a long gentle western slope and a short steep eastern escarpment that
culminates in its highest peaks. It is 50 to 80 miles wide and iiuis west
of north through eastern California for more than 400 miles- — from
the Mojave Desert on the south to the Cascade Range and Modoc
Plateau on the north. Mount Wliitney, in the southeastern part of the
range, attains a height of 14,495 feet and is the highest point in the
conterminous 48 States. The "High Sierra,-' a spectacular span of the
crest, which extends north from Mount Whitney for about a hundred
miles, is characterized by a procession of 13,000- and 14,000-foot peaks.
The Sierra Nevada is a tremendous physical barrier and a highly
effective trap for capturing moisture from air moving eastward from
the Pacific. Warm moist air from the ocean is forced upward into
colder regions ; and because cool air can hold less moisture than warm
air, precipitation across the Sierra Nevada is heavy. The small pre-
cipitation in the arid Great Basin to the east, in the rain shadow of the
Sierra Nevada, is evidence of the effectiveness of the Sierra Nevada as
a trap for moisture.
General Geologic Relations
The Sierra Nevada is a huge block of the earth's crust that has
broken free on the east along the Sierra Nevada fault system and been
tilted westward. It is overlapped on the west by sedimentary rocks
of the Great Valley and on the north by volcanic sheets extending
south from the Cascade Range. Volcanic sheets cap large areas in the
north part of the range.
Most of the south half of the Sierra Nevada and the east half of the
north part is composed of plutonic (chiefly granitic) rocks of Mesozoic
age. These rocks constitute the Sierra Nevada batholith, which is part
MINERAL AND WATER RESOURCES OF CALIFORNIA 55
of a belt of plutonic rocks that runs southward into Baja California
and northward into western Nevada, Idaho, and British Columbia.
In the north half of the range the batholith is flanked on the west by
the western metamorphic belt, a terrane of strongly deformed and
metamorphosed sedimentary and volcanic rocks of Paleozoic and
Mesozoic age. J^The famed Mother Lodt passes through the heart of
the western metamorphic belt. Farther south, scattered remnants of
metamorphic rock are found within the batholith, especially in the
western foothills and along the crest in the east -central Sierra Nevada.
Sedimentary strata of Paleozoic and late Precambrian age predomi-
nate east of the Sierra Nevada in the Wliite and Inyo Mountains.
Paleozoic and Mesozoic Stratified Rocks
The Paleozoic strata in the metamorphic remnants of the eastern
Sierra Nevada are chiefly metamorphosed sandstone, shale, and lime-
stone, whereas those in the western part of the range contain abundant
volcanic rocks and sedimentary rocks that were derived from volcanic
rocks. The materials in the eastern strata were derived chiefly from
the erosion of older terranes and accumulated in shallow seas where
limestone reefs flourished (miogeosynclinal environment) ; on the other
hand, much of the materials in the western strata were derived from
volcanic outpourings and accumulated to great thickness in deeper
parts of the ocean (eugeosynclinal environment).
The most complete section of Paleozoic rocks in the eastern Sierra
Nevada is in the Mount Morrison roof pendant, where more than
30,000 feet of strata of Ordovician to Permian ( ? ) age are exposed.
Tliere the oldest rocks, chiefly slate and chert, are overlain by sandy
limestone and calcareous sandstone; these strata are overlain, in turn,
by thin-bedded hornfels that was derived from siltstone, mudstone,
and shale.
In the western metamorphic belt, most of the Paleozoic strata have
been referred to the Calaveras Formation, which contains sparse fossils
of Permian age in its upper part, but which is very thick and for the
most part unfossiliferous. However, strata of Mississippian and
Silurian ( ?) ages are present in the Taylorsville area, at the north end
of the belt. In the southern part of the western metamorphic belt, the
most extensive Paleozoic rocks are carbonaceous phyllite and schist
with thinly interbedded chert, but lenses of mafic volcanic rocks and
carbonate are widespread and locally attain thicknesses of several
thousand feet. In the northern part, mafic volcanic rocks, slate, and
sandstone constitute about equal parts of the Paleozoic section.
Strata of Mesozoic age crop out in several northwest -trending belts
that parallel the long axis of the Sierra Nevada. In the eastern part
of the range, a belt of metamorphic remnants that contains Mesozoic
strata extends for more than 150 miles. The rocks in this belt are
chiefly volcanic rocks of intermediate composition and graywacke-
type sandstone derived chiefly from volcanic rocks. These rocks
weather gray and contrast strongly with nearby strata of Paleozoic
age which weather reddish brown. The thickest section of Mesozoic
strata is exposed in the Ritter Range roof pendant and is about 30,000
feet thick. Early Jurassic fossils have been collected from a locality
about 10,000 feet above the base of this section.
56 MINERAL AND WATER RESOURCES OF CALIFORNIA
In the western metamorphic belt, the Paleozoic strata are flanked
by Mesozoic strata on the west and, in the north part, also on the east.
In additi6n, at least part of the strata in a g:ronp of roof pendants that
extends for about 65 miles southeast through the heart of the batholith
from lat ';}T° N. is of Mesozoic age.
These strata of the western metamorphic belt have yielded both
Triassic and Jurassic fossils, but Triassic strata are of small extent
and m.ost of the strata are Upper Jurassic. The Upper Jurassic rocks
include sequences of slate, graywacke, conoflomerate, and volcanic
rocks. These rocks commonly are interbedded and in places inter-
tongue with volcanic rocks.
The Paleozoic and Mesozoic strata of the Sierra Nevada have been
complexly folded and faulted, and steep or vertical beds, cleavage, and
lineations, including fold axes, are common. A predominance of op-
posing, inward-facing top directions in the strata on the two sides of
the range define a complex faulted synclinorium, the axial part of
which is occupied by the granitic rocks of the batholith. The axis of
the synclinorium trends about N. 40° W. in the central part of the
range but trends northward in the northern part.
The eastern limit of the synclinorium is marked by a belt of Pre-
cambrian and Cambrian rocks that extends from the White Mountains
southeastward into the Death Valley region. The western limit pre-
sumably lies beneath the Cretaceous and Tertiary strata of the Great
Valley. The range-front faults that bound Owens Valley and the east
side of the Sierra Nevada strike obliquely across the major structures
in the Paleozoic and Mesozoic strata. In the White and Inyo Moun-
tains and in many remnants within the Sierra Nevada batholith the
strata are strongly folded and faulted, causing many repetitions of
formations, but in the Mount Morrison and Ritter Eange pendants of
the eastern Sierra Nevada the gross structure is homoclinal, and tops
of beds face west across more than 50,000 feet of vertical or steeply
dipping strata ranging from Ordovician to Jurassic in age.
In the western metamorphic belt the gross distribution of strata
resulting from the development of the synclinorium has been reversed
by movement along steeply dipping fault zones of large displacement,
and the Paleozoic strata lie between two belts of Mesozoic strata. The
internal structure of the individual fault blocks is, in general, homo-
clinal, and most tops are to the east; beds dip eastward steeper than
60°. The homoclinal structure is interrupted in parts of the belt by
both isoclinal and open folds, but even in such places the older strata
of a fault block generally are exposed near its west side and the
younger strata near its east side.
The Sierra Nevada lies within the mobile belt of the western Cordil-
lera and represents part of the extended deformation within that re-
gion. The steep dips of thick stratigraphic sequences Avithin the
Sierra Nevada indicate that the amplitude of the synclinorium was
very great and that the sialic upper crust was depressed deeply into
the region of the lower crust or mantle. This circumstance and the
localization of the granitic rocks in the axial region of the syncli-
norium suggests that the magmas that rose from depth and crystal-
lized to granitic rock were formed by partial fusion of sialic rocks
that had been depressed into regions of high temperature.
MINERAL AND WATER RESOURCES OF CALIFORNIA 57
The Batholith
The batliolith is composed chiefly of quartz-bearing granitic rocks
ranging in composition from quartz diorite to alaskite, but includes
scattered smaller masses of darker and older plutonic rocks as well as
renuiants of Paleozoic and Mesozoic metamorphic rocks. In gen-
eral, granodiorite and quartz diorite predominate in the western Sierra
Nevada and quartz monzonite in the eastern Sierra Nevada, but some
felsic plutons are f omid in the west and some mafic ones in the east.
Tlie granitic rocks are in discrete masses or plutons that are in sharp
contrast with one another or are separated by thin septa of meta-
morphic or mafic igneous rocks or by late aplitic dikes. Individual
plutons range in area from less than a square mile to several hundred
square miles — the limits of many large plutons have not been deline-
ated. On the whole, the batholith appears to consist of a few large
plutons and a great many smaller ones. All of the larger and some
of the smaller plutons are elongate in a northwesterly direction, paral-
lel with the long direction of the batholith, but many of the smaller
ones are elongate in other directions or are irregularly shaped or
roimded. \^
Isotopic dates of minerals by the potassium-argon method and of
whole rocks by the rubidium-strontium method suggest at least three
age groups of granitic rocks. In the eastern Sierra Nevada several
granodiorites are at least 180 million years old (Late Triassic or Early
Jurassic) ; in the western Sierra Nevada the plutons appear to be 140
to 150 million years old; and along and just west of the crest the
plutons appear to be 80 to 90 million years old (early Late Cretaceous) .
The batholith is almost devoid of mineral deposits except for con-
tact-metasomatic deposits of tungsten. Nevertheless, the batholith is
generally thought to be the source of the many deposits of gold, copper,
lead, zinc, and silver peripheral to it. Major tungsten deposits occur
in the eastern Sierra Nevada where Paleozoic carbonate rocks are in
contact with silicic intrusives, and in the western Sierra Nevada in a
migmatite zone in granodiorite. Rich deposits of gold, copper, chrome,
limestone, and building stone are present in the western metamorphic
belt.
During the Early Cretaceous the Sierra Nevada was part of a nar-
row north-trending highland that lay between the Pacific region and
the Rocky Moimtain geosyncline. The enormous quantities of ma-
terial that were deposited in those areas suggest deep erosion of the
Sierra Nevada region, amounting to several miles, between the em-
placement of the Late Jurassic and the early Late Cretaceous plutons.
The amomit of material eroded from the Sierra Nevada since the end
of the Cretaceous has been much less — perhaps only a mile or two on
the average. Thus it seems probable that the present level of exposure
is much deeper into the Jurassic intrusives than into the Cretaceous
intrusives. ^v
Uplift and Sculpturing of the Sierra Nevada
The sedimentary deposits in the Great Valley were deposited across
the downslope continuation of the tilted Sierra Nevada block. Dur-
ing the Tertiaiy, a deep basin formed in the southern part of the Great
Valley while only a shallow basin formed in the north part, suggesting
67-164 0^«6— pt. I 5
\
\
58 MINERAL AND WATER RESOURCES OF CALIFORNIA
much greater tilting and uplift of the southern than of the northern
Sierra Nevada. A deep Cretaceous basin in the north part of the Great
Valley suggests precisely opposite conditions during the Cretaceous —
that is, greater tilting and uplift of the northern Sierra Nevada.
The volumes of sedimentary rocks that have collected in the Great
Valley during different epochs indicate that the rate of sedimentation
increased progressively during the Tertiary. This suggests, in turn,
that the a^^erage rate of uplift of the Sierra Nevada also increased
progressively during the Tertiary although there is evidence to indi-
cate that tilting and uplift occurred at irregular intervals. The de-
tails of uplift have been studied from records of erosion surfaces, from
the profiles of ancient and modern streams, and from the sedimentary
histoi-y in the Great Valley. The minimum ages of landforms have
been determined from animal and plant remains collected from sedi-
mentary deposits that rest on the landforms and by potassium-argon
dating of volcanic rocks.
During the first part of the Tertiarj' the Sierra Nevada was a broad,
gently sloping upland. Gold-bearing gravels were deposited in broad
graded streams during the Eocene and Oligocene. In late Miocene
time extensive bodies of rhyolite tuff and associated gravel (Valley
Springs Formation) were deposited across the old landscape of the
northern Sierra Nevada. Somewhat later, during the Pliocene, ande-
sitic mudflows together with conglomerate and sandstone (Mehrten
Formation) buried the northern Sierra Nevada under a volcanic
blanket that ranged from 1,500 feet thick at the west foot of the range
to more than 4,000 feet along the crest. These eruptions buried the
old drainages, and new drainages were then developed upon the con-
structional surface of the volcanic rocks. Apparently, the southern
Sierra NevacDt was not affected by widespread volcanism, although
volcanic outpourings took place locally.
During the later part of the Tertiary, sporadic westward tilting
resulted in rhe uplift of erosion surfaces to different levels. Tlie most
recent major uplift occurred after volcanic rocks, with a potassium-
argon age of about 3 million years, were erupted, and as a result streams
were entrenched in narrow, steep-sided can3'ons.
During the early stages of uplift, the southern Sierra Nevada was
the west flank of a broad arch that extended across the region east
of the Sierra Nevada to Death Valley, and it seems likely that some
such structure also existed for the northern Sierra Nevada. As the
curvature of the arch increased, faults began to form and eventually
the crest and east flank of the arch broke up to form Owens Valley
and the basins and ranges eastward to Death Valley.
During the Pleistocene, after the crest of the Sierra Nevada had
been uplifted to near its present height, glaciers formed and swept
down canyons both to the east and to the west. These glaciers sharj)-
ened peaks, rounded canyons to U -shapes, and formed myriad other
forms that add so much to the interest and beauty of the Sierran
landscape.
The last uplifts and glaciations took place so recently that we cannot
say they are of the past. Continued earth movements are indicated
by earthquakes and minor seismic activity along the east side and
near the south end of the range and by geodetic measurements. Only
MINERAL AND WATER RESOURCES OF CALIFORNIA 59
a slight increase in average winter precipitation, especially if accom-
panied by lowering of the average summer temperature, would initiate
a new epoch of glaciation.
Selbxjted references
Bateman, P. C, Clark, L. D., Huber, N. K., Moore, J. G., and Rinehart, C. D.,
1963, The Sierra Nevada batholith — a synthesis of recent work across the
central part : U.S. Geo!. Survey Prof. Paper 414-D, p. D1-D46.
Clark, L. D., 1965, Stratigraphy and structure of part of the western Sierra
Nevada metamorphic belt: U.S. Geol. Survey Prof. Paper 410, 70 p.
Durrell, Cordell, 1940, Metamorphism in the southern Sierra Nevada northeast
of Visalia, California : California Univ. Dept. Geol. Sci. Bull., v. 25, p. 1-118.
Ferguson, H. G., and Gannett, R. W., 1932, Gold quartz veins of the Alleghany
district, California : U.S. Geol. Sur\^ey Prof. Paper 172, 139 p.
Johnston, W. D., 1940, The gold quartz veins of Grass Valley, California : U.S.
Geol. Survey Prof. Paper 194, 101 p.
Knopf, Adolph, 1918, A geological reconnaissance of the Inyo Range and eastern
slope of the southern Sierra Nevada, with a section on the stratigraphy of
the Inyo Range, by Edwin Kirk: U.S. Geol. Survey Prof. Paper 110, 130 pi
, 1929, The Mother Lode system of California: U.S. Geol. Survey Prof.
Paper 157, 88 p.
Lindgren, Waldemar, 1911, The Tertiary gravels of the Sierra Nevada : U.S. Geol.
Survey Prof. Paper 73, 226 p.
Lindgren, Waldemar, Turner, H. W., and Ransome, F. L., (individually and
coauthors), 1894-1900, "The Gold Belt folios": U.S. Geol. Survey Atlas, Folios
3, 5, 11, 17, 18, 29, 31, 37, 41, 43, 51, 63. 66.
Macdonald, G. A., 1941, Geology of the western Sierra Nevada between the Kings
and San Joaquin Rivers, California : California Univ. Dept. Geol. Sci. Bull.,
V. 26, no. 2, p. 215-286.
Matthes. F. E., 1930, Geologic history of the Yosemite Valley : U.S. Geol. Survey
Prof. Paper 160, 137 p.
Muir. John, 1879, Studies in the Sierra: Overland, v. 12, p. 393-403, 489-500;
V. 13, p. 67-69, 174-l&i, 393-401, 530^40; v. 14, p. 64-73. ^
, 1880, Ajicient glaciers of the Sierra, California : Californian, v. 2, p.
550-557.
GEOLOGY OF THE GREAT BASIN SOUTH OF THE 39TH PARALLEL
(By J. H. Stewart and D. C. Ross, U.S. Geological Survey, Menlo Park, Calif.)
The Great Basin in California south of the 39th parallel is a tri-
angular-shaped area lying east of the Sierra Nevada, north of the
Mojave Desert, and west of the continuation of the Great Basin into
Nevada. The region consists of high mountain blocks trending gen-
erally north-northwest separated by deep basins. The contrast in
elevation between the mountains and basins is great. The lowest part
of Death Valley is 282 feet below sea level, the lowest point on the
North American continent, and the Panamint Range west, of Death
Valley rises to over 11,000 feet. Owens Valley, a promment trough
along the western side of the region, lies generally about 4,000 feet
above sea level, and the AVhite-Inyo Mountains on the east and the
Sierra Nevada on the west both rise to over 14,000 feet.
The decipherable geologic history of the region has been long and
complex. The preserved record indicates long periods of marine
deposition, shorter periods of orogeny (mountain building) and gra-
nitic intrusion, and both ancient and fairly recent volcanic activity.
Inasmuch as the Great Basin geology of California is so closely related
to that of Nevada, readers are also referred to the geologic summary
(p. 11-39) in the report on the mineral and water resources of Nevada
(Nevada Bureau of Mines Bull. 65, 1964) .
60 MINERAL AND WATER RESOURCES OF CALIFORNIA
The ranges of the Great Basin are characterized by complex struc-
ture— tight folds, high-angle faults, and low-angle thrust faults are
common. Vertical movement on the numerous high- angle faults has
been a major factor in outlining the basins and ranges, which give
the region its desolate scenic beauty. Major high-angle faults essen-
tially bound the region on the west (Sierra Nevada frontal fault) and
on the south (Garlock fault) . Other major high-angle faults lie along
one or both sides of Panamint Valley, Saline Valley, and Owens Val-
ley, and along Death Valley. In addition to vertical movement, the
Death Valley-Furnace Creek fault system may have as much as 50
miles of right-lateral offset. A major low-angle thrust fault system
is found in the southern Death Valley area (Amargosa thrust), and
an as yet unnamed thrust, segments of which have been identified in
the Inyo, Last Chance, and Saline Ranges, may have moved late Pre-
cambrian and Cambrian strata more than 20 miles over upper Paleo-
zoic rocks.
The tectonic forces that cracked the earth's crust in these tremen-
dous movements are still being felt. In 1872 one of the largest historic
earthquakes in the United States shook Owens Valley; the zone of
visible faults associated with this earthquake extends for more than
100 miles along the valley.
The oldest rocks exposed in this part of the Great Basin consist
largely of gneiss, schist, and granitic rock that crop out mostly in the
ranges around Death Valley and locally elsewhere in the southernmost
part of the region. On the basis of radiometric ages of zircon (Lan-
phere and others, 1963), these rocks are about 1,800 m.y. old. These
rocks were probably originally clastic sediments which were later in-
volved in orpgenic movements, metamorphosed, and intruded by
granitic rocks. They form the basement of the thick section of upper
Precambrian, Paleozoic, and Mesozoic sedimentary rocks.
During late Precambrian time a marine trough developed in the
region and many thousands of feet of sediment were deposited. The
oldest of these deposits belongs to the Pahrump Series which consists
of phyllitic siltstone, quartzite, conglomerate, limestone, and dolomite,
and is as thick .as 7,000 feet. These strata were intruded by diabase
during the Precambrian, and talc deposits formed near the contacts
of the diabase and carbonate rocks. Locally, uplifts occurred within
the basin of deposition during and immediately after the time the
Pahrump Series w.as being deposited.
Following deposition of the Pahrump Series, a clastic section com-
posed dominantly of marine sand and silt was laid down during the
remainder of the late Precambrian and during the Early Cambrian.
This section is over 10,000 feet thick. These strat.a were derived from
source areas to the east and southeast, of the region and were deposited
in a northeast-trending trough that deepened to the west. The basal
formation of this section, the Noonday Dolomite, contains large de-
posits of lead, silver, and zinc.
Above the clastic section of late Precambrian and Early Cambrian
age is a section of marine carbonate rocks ranging in age from Middle
Cambrian to Devonian. These strata are locally about 12,000 feet
thick. In Nevada, strat.a of this age are divided into three assem-
blages, an eastern carbonate assemblage of nearshore to offshore, shal-
MINERAL AND WATER RESOURCES OF CALIFORNIA 61
low- water deposits; a transitional assemblage of offshore, mostly
shallow- wat-er deposits of shale, limestone, and chert; and a western
siliceous and volcanic assemblage of offshore, mostly deep-water de-
posits (Roberts, in Nevada Bur. Mines Bull. 65, 1964, p. 22-25) . The
deposits of this age in California are mostly part of the eastern car-
bonate assemblage, although some deposits in the Inyo Mountains
probably belong to the transitional assemblage. Deposits in the Si-
erra Nevada west of the Great Basin definitely belong to the transi-
tional assemblage.
During the Mississippian a mountain chain rose in about the same
area as the present southern Sierra Nevada, and coarse detrital ma-
terial derived from this highland was deposited in the southern Great
Basin. This mountain chain extended into central Nevada where the
orogenic event that produced the chain is referred to as the Antler
orogeny (Roberts and others, 1958). The mountain building in
Nevada was accompanied by large-scale thrusting of lower Paleozoic
strata to the east. Thrusting of this age, however, has not been recog-
nized in the southern Great Basin in California, but a mid-Paleozoic
unconformity in the Inyo Mountains may reflect the marginal effects
of this orogeny. The amount of coarse detrital material derived from
the Antler orogenic belt decreases rapidly during the Mississippian.
Later in the Mississippian and also in the Pennsylvanian, fine silt and
minor amounts of carbonate were deposited in the western part of the
Great Basin in California. Deposits of these periods become more
limy to the east and are dominantly carbonate rock near the California-
Nevada state line. The Mississippian and Pennsylvanian strata are
over 6,000 feet thick in the Great Basin in California.
Coarse detrital material was again introduced into the basin during
the Permian, apparently from a source area to the west in the site of
the present Sierra Nevada. This orogenic event is i-eferred to as the
Sonoma orogeny in Nevada (Silberling and Roberts, 1962) . Deposits
of Permian age are about 3,000 feet thick.
At the start of the Triassic, fine marine muds were deposited in a
north-south trough in the Great Basin in California. The highlands
that existed in the site of the Sierra Nevada during Permian time
apparently sank below the sea before Triassic time, as the Triassic
strata do not contain coarse debris that would indicate the presence of
a highland. The marine Triassic deposits, which are about 2,000 feet
thick, are overlain by at least 7,000 feet of volcanic rocks of Triassic
and Jurassic age.
During the Jurassic and Cretaceous in the Great Basin in Cali-
fornia, orogenic movements took place and great granitic batholiths
were emplaced. Most of the stiiictural features in the region, except
for Cenozoic liigh-angle faulting, were probably produced during
these periods. The dates of emplacement of the granitic bodies is
established on the basis of radiometric K-Ar dating. The contacts
of these granitic rocks with Paleozoic limestone and dolomite are the
site of many tungsten, talc, and silver-lead-zinc deposits. Gold-silver-
quartz veins are probably also related to this period of granitic
intrusion.
During the Tertiary, thick continental deposits were laid down in
local basins and volcanic activity was widespread. The thickest
62 MINERAL AND WATER RESOURCES OF CALIFORNIA
Tertiary sedimentary sections are in the Death Valley region, and
some of these strata contain deposits of borate minerals. Volcanic
activity was prominent a short distance east of Death Valley (the
Greenwater Volcanics) and also along^ the western side of the Great
Basin in California. Large caldera-like features (volcano-tectonic
structures) fonned in Long Valley and at Mono Lake. These volcanic
centers were the source for thick deposits of ash-fall and ash-flow
tuffs, and lava flows. At the Mono Craters volcanic center, among the
latest formed features are domes of obsidian within shallow craters in
pumice. The last volcanic event in much of the Great Basin in
California was the extrusion of basalt and the formation of cinder
cones. Ubehebe Crater, an explosion vent in basaltic rocks in the
northern part of Death Valley, and the many cones in the Coso
Moimtains, are examples of this episode.
In the latter part of the Tertiary, the physiographic features — the
basins and ranges — began to take the shape we see today. High-angle
faulting was dominant, outlining momitain blocks and defining the de-
pressed basin areas. This basin-range faulting is still continuing — as
late as the 1950's, tens of feet of vertical movement along such faults
resulted in strong earthquakes in the Great Basin in neighboring
Nevada.
The increased precipitation that accompanied Pleistocene glaciation
developed a system of large lakes in the Great Basin. Lake Manly,
one of the better known lakes, filled Death Valley to a depth of about
600 feet. The return of the arid conditions we know today dried out
these lakes to form the saline lakes and barren playas so characteristic
of this region. Borates, potassium and sodium compounds, lithium,
phosphate, and bromine are recovered commercially at Searles Lake
and Owens Lake from these lake deposits and their associated brines.
During the latest history of the region, and continuing today, erosion
of the mountain ranges and deposition of the debris has formed con-
spicuous alluvial fans along the flanks of the ranges.
Selected Rb:ferences
Lanphere, M. A., Wasserburg, G. J. F., and Albee, A. L., 1963, Redistribution
of strontium and rubidium isotopes during metamorphisni, World Beater Com-
plex. Panamint Range. California, in Isotopic and Cosmic Chemistry : Am-
sterdam, North-Holland PubUshing Co., p. 269-^20.
Nevada Bureau of Mines, 1964, Mineral and water resources of Nevada, pre-
pared by the U.S. Geological Survey and the Nevada Bureau of Mines: U.S.
Senate Doc, Nevada Bur. Mines Bull. 65, 314 p.
Roberts, R. J., Hotz, P. E., Gilluly, James, and Ferguson, H. G., 1958, Paleozoic
rocks of north-central Nevada : Am. Assoc. Petroleum Geologists Bull., v. 42,
no. 12, p. 2,813-2,857.
Silberling, N. J., and Roberts, R. .!., 1962. Pre-Tertiary stratigraphy and structure
of northwestern Nevada : Geol. Soc. America Spec. Paper 72. 52 p.
GEOLOGY OF THE MOJAVE DESERT REGION
(By T. W. Dibblee, .Jr., and D. F. Hewett, U.S. Geological Survey, Menlo
Park, Calif.)
The Mojave Desert is an area of low mountain ranges that separate
many undrained alluviated basins or valleys. In the western part
these have no definite pattern, but in the central and eastern parts
MINERAL AND WATER RESOURCES OF CALIFORNIA 63
many of them trend northwest and north. Relief increases eastward
as altitudes of the alluviated valleys decrease from 4,000 feet at the
western margins of the desert to near sea level at the Colorado River.
The rocks of the Mojave Desert province are separable into two
major divisions, (a) pre-Cenozoic rocks, and (b) Cenozoic sedimen-
tary and volcanic rocks. The pre-Cenozoic rocks are composed of (1)
metamorphic and old sedimentary rocks, and (2) igneous rocks.
The metamorphic rocks are gneisses and schists of known and prob-
able Precambrian age. They were recrystallized at great depth from
rocks that were mostly sedimentary and which formed enormously
thick sections. The gneisses are coarsely crystalline banded rocks
composed mostly of quartz, feldspar, and biotite mica. They are ex-
posed east and south of Baker, near Barstow and Randsburg, and near
the southwestern border of the Mojave Desert. In a few places the
gneisses contain deposits of rare-earth and radioactive minerals. The
schists are foliated micaceous rocks. They are exposed only near
Randsburg and in the Orocopia and Chocolate Mountains in the south-
ern part of the desert.
Old sedimentary rocks, mapped as the Pahrump Series of late Pre-
cambrian age, are found in only two areas in the extreme northeastern
part of the Mojave Desert; one in the Silurian Hills north of Baker
and the other farther east in the Kingston Mountains. This unit
rests unconformably on gneiss, is many thousands of feet thick, and
consists mostly of quartzite, shale or hornfels, and dolomite.
The Precambrian rocks are overlain unconformably by a great
thickness of old marine sedimentary strata of Paleozoic age, divided
into formations as shown on the columnar section (fig. 3). They are
most extensive in the northeastern Mojave Desert near the Nevada
state line, notably in the Kingston, Ivanpah, and Providence Moun-
tains. The lower half of this stratigraphic section is of Cambrian
age; in the Kingston and Ivanpah Mountains this section is mostly
quartzite and shale (the basal unit, the Noonday Dolomite, has re-
cently been assigned to the Precambrian). In the Providence Moun-
tains the basal part of the Cambrian section is quartzite, the remainder
is mostly limestone and dolomite. The rest of the Paleozoic (Devon-
ian to Permian) section in these areas is mostly limestone and dolo-
mite. Remnants of similar rocks of known and probable Paleozoic
age engulfed in granitic intrusive rocks occur in many other parts of
the desert, notably in the mountains southwest of Needles, in areas
southeast of Twentynine Palms, in areas near Victorville, and in the
Tehachapi Mountains west of Mojave.
Two nonmarine sedimentan' formations of Triassic and Jurassic
ages have been mapped in several places near the Nevada state line.
Marine formations of these ages were recognized at one place near
Baker, and possibly at another near Barstow. The thick section of
slate (pre-Cenozoic rocks of unknown age) in the southeastern Mojave
Desert near Blythe may be of this age.
The pre-Cenozoic igneous rocks are of two types, metavolcanic and
plutonic. The metavolcanic (and hypabyssal) rocks are mostly ande-
sitic porphyry of Mesozoic age that f omi a complex of extrusive and
shallow intrusive masses and dike swarms in the central Mojave
Desert.
64 MINERAL AND WATER RESOURCES OF CALIFORNIA
The pliitonic igneous rocks are coarsely ciystalline and were em-
placed at great depth. Most are granitic, are widespread, and make
up the major part of the pre-Cenozoic rocks of the Mojave Desert.
The oldest of these are granitic rocks (quartz monzonite) exposed in
the northeastern part (Hewett, 1956), and anorthosite and syenite in
the Orocopia Mountains east of Salton Sea (Crowell and Walker,
1962) . All are of Precambrian age and intrude gneiss. Gray granitic
rock (quartz monzonite) of Jurassic ( ?) age is A^-idespread in the east-
central Moj a ve Desert, Gray to black diorites and gabbros of Mesozoic
age crop out locally in many parts of the desert. All these Mesozoic
plutonic rocks are intrusive into the metamorphic and old sedimentary
rocks. Nearly all the above-mentioned i)re-Cenozoic rocks are in-
truded by gray-white granitic rock (q[uartz monzonite to granite) of
Cretaceous age that is very extensive in almost all parts of this prov-
ince, especially in the western and central parts.
Metallic mineral deposits containing sulfides of iron, copper, lead,
zinc, and silver, and commonly containing disseminated gold and
silver, form veins in pre-Cenozoic rocks in many parts of the desert
region. Most are found in metamorphic and old sedimentai-y rocks
near intrusive contacts with granitic rocks; many occur in the granitic
rocks. Tungsten ores occur under similar conditions. Other deposits
containing these minerals except tungsten are found in fault or shear
zones in these rocks. Deposits of iron ores are found in old sedimen-
tary rocks along or near contacts with the intrusive granitic rocks of
Jurassic(?) age. In the southwestern Mojave Desert, limestone is
being quarried extensively for industrial uses, mainly for cement
manufacture.
The Cenozoic sedimentary and volcanic rocks lie uncomformably
upon the pre-Cenozoic rocks which were deeply eroded during Cre-
taceous time. Those of early Tertiary age are sedimentary and are
known in only one area strictly within the jDrovince, namely in the
Orocopia Mountains east of Salton Sea where about 2,500 feet of ma-
rine sandstone (Maniobra Fonnation of Crowell and Susuki, 1959) of
Eocene age are exposed.
Elsewhere on the Mojave Desert the Tertiary volcanic and sedi-
mentary rocks are nonmarine, of middle and late Tertiary age, and
are widespread. The most extensive Tertiary unit is an assemblage,
as thick as 10,000 feet, of volcanic lava flows, breccias, tuffs, and some
sedimentary rocks, of probable Oligocene to early Miocene age. It is
exposed in many areas in all but the southwestern part of the prov-
ince. The volcanic rocks, which range from rhyolite through andesite
to basalt, were erupted from groups of vents and fissures, later filled
with volcanic plugs, in many areas within these parts. Near Mojave
in the western Mojave Desert, this assemblage was named the Gem
Hill Formation of the Tropico Group ; in areas north of Barstow, as
the Pickhandle Formation. Elsewhere it is not named. Ores of gold
and silver, some very rich, were mined from veins in the volcanic
plugs associated with this unit, notably near Mojave, Randsburg,
Barstow, and Ludlow. These plugs contain veins of barite near
Barstow and Ludlow and manganese ore near Ludlow. The volcanic
rocks also contain perlite, pumicite, and tufi", of commercial grades.
The above-described volcanic and sedimentary unit is overlain, in
MINERAL AND WATER RESOURCES OF CALIFORNIA 65
places imconformably, by a predominantly sedimentary unit as thick
as 5,000 feet of middle Miocene to early Pliocene age. In tlie \yestern
Mojave Desert it is known as the Barstow Formation near Barstow;
Punchbowl Formation at Cajon Pass; and Fiss Fanglomerate near
Kosamond. At the west end of the Mojave Desert this unit grades
westward into marine beds. Commercial minerals in this unit include
the world's largest deposit of borate minerals that are being mined
from lake-bed shale near the base of this unit at Boron. Similar lake-
bed shales of this unit contain deposits of borate and strontiimi min-
erals and of absorptive tuff or bentonite, near Barstow, Yermo, and
Ludlow.
Stratigraphic sections of middle and late Pliocene age are exposed
in the northern part of the province, notably west of Mojave and east
of Randsburg. In the Eandsburg area the section includes andesite
flows and tuffs associated with andesitic intrusions. In other parts
of the province much of the dissected alluvial sediments may be of
this age.
Deposits of Quaternary age that fill the desert valleys are mainly
alluvial sediments, some lake-bed clays, and dune sand. In a few
places they include local basalt flows and cinder cones. The cinder
cones are composed of basaltic pumice which is quarried for industrial
uses. The clays of Bristol Lake near Amboy in the central Mojave
Desert contain enormous deposits of salt with calcium chloride which
are being quarried for industrial uses.
The pre-Cenozoic metamorphic and old sedimentary rocks of the
Mojave Desert province are complexly folded, faulted, and intruded
by plutonic igneous rocks. These igneous rocks, mostly granitic,
which extend southeastw^ard from the Sierra Nevada province,
assimilated most, of the pre-exisiting rocks. All this happened during
the Mesozoic Era.
The Tertiary stratified rocks which rest on the deeply eroded surface
of the pre-Cenozoic rocks are themselves tilted, faulted, and deformed
into folds mth axes that trend mostly west to northwest. They were
deformed during late Tertiary and early Quaternary time. In many
places Quaternary alluvial sedunents and basalt flows are slightly
deformed in the same manner.
The Mojave Desert Region is in large part bounded geologically on
the southwest by the San Andreas fault and on the northwest by the
Garlock fault, or physiographically by mountain ranges uplifted along
these master faults. Both are vertical, active faults along w^hich move-
ment was mainly horizontal ; the area southwest of the San Andreas
fault has moved northwest, and that, northwest, of the Garlock fault
has moved southwest, relative to the wedge-shaped block that forms
the major part of the Mojave Desert province. The southwest half of
the Mojave block itself is broken by a number of vertical faults parallel
to the San Andreas fault. Along many of these faults the terrain has
slipped horizontally as on the San Andreas. South of the Garlock
fault, and north of Salton Sea, the Mojave block is broken by some
vertical faults that trend east, along which the terrain has slipped in
part, horizontally ns on the Garlock fault. All or most of these faults
within the Mojave block involve Quartemary formations and are
therefore active. The Garlock fault becomes a southw^est-dipping
66 MINERAL AND WATER RESOURCES OF CALIFORNIA
thrust fault at its east end as it curves southeastAvard around the
Avawatz Mountains.
The structural pattern of the eastern part of the Mojave Desert
province differs from that of the western and central parts and is more
like that of the Basin and Range province to the north. In this part
the old sedimentary rocks are compressed into folds vnih axes that
trend mostly north ; some are broken by low-dipping thrust faults that
are themselves folded. Most of this deformation occurred before or
during the invasion of the Mesozoic granitic rocks, but some of the
thrust faults involve lower Pliocene formations. Some of these show
no topographic expression and therefore have long been inactive.
Selejcted References
Bassett, A. M., and Kupfer, D. H., 1964, A geologic reconnaissance of the south-
eastern Mojave Desert, California : California Div. Mines and Geology Spec.
Rept. 83, 43 p.
Bowen, O. E., Jr., 1954, Geology and mineral resources of the Barstow quadrangle,
California : California Div. Mines Bull. 165, 208 p.
Crowell, J. C, and Susuki, Takeo, 1959, Eocene stratigraphy and paleontology,
Oricopia Mountains, southeastern California : Geol. Soc. America Bull., v. 70,
no. 5, p. 581-592.
Crowell, J. C, and Walker, J. W. R., 1962, Anorthosite and related rocks along
the San Andreas fault, southern California : California Univ. Geol. Sci. Pub..
V. 40, no. 4, p. 219-288.
Gardner, D. L., 1941, Geology of the Newberry and Ord Mountains. San Bernar-
dino County, California : California Jour. Mines and Geology, v. 36, no. 3,
p. 257-304.
Hewett, D. F., 1954a, General geology of the Mojave Desert region, California,
in Geology of southern California : California Div. Mines Bull. 170, chap. II,
contr. 1, p. 5-20.
, 1954b, A fault map of the Mojave Desert region, in Geology of southern
California: California Div. Mines Bull. 170, chap. IV, contr. 2, p. 15-18.
1956, Geology and mineral resources of the Ivanpah quadrangle, Cali-
fornia and Nevada : U.S. Geol. Survey Prof. Paper 275, 172 p.
Hulin, C. D., 1925, Geology and ore deposits of the Randsburg quadrangle of
California : California Bur. Mines Bull. 95, p. 1-148.
Simpson, E. C, 1934, Geology and mineral deposits of the Elizabeth Lake quad-
rangle, California : California Jour. Mines and Geology, v. .30, p. 371^15.
GEOLOGY OF THE TRANSVERSE RANGES
(By T. W. Dibblee, Jr.. U.S. Geological Survey, Menlo Park, Calif.)
The Transverse Range region is one of eastward-trending mountain
ranges and valleys. It is so named because this trend is transverse to
the generally northwesterly trending features of southern California.
The lowlands of the San Bernardino and Los Angeles plains of the
eastern part of this region rise abruptly northward to the San Bernar-
dino and San Gabriel Mountains, respectively, two of the most rugged
and highest ranges in southern California. Westward the San Gabriel
Mountains split into two mountain chains, including the Santa Ynez
Range on the north and the Santa Susana Range on the south, sep-
arated by the Santa Clara River Valley. Westward from Los Angeles
stretch the Santa Monica Mountains, and their westward projection
into the sea is formed by the four channel islands, north of which lies
the Santa Barbara channel.
MINERAL AND WATER RESOURCES OF CALIFORNIA 67
The rock units of the Transverse Kange region may be divided into
two main groups, (a) crystalline basement complex of met amorphic
and plutonic rocks, and (b) sedimentary and volcanic rocks.
The basement complex, exposed mostly in the eastern part of the
province, is composed of hard crystalline metamorphic rocks and plu-
tonic igneous rocks. It forms the old terrane upon which the sedimen-
tary and volcanic rocks were deposited. The metamorphic rocks ciy-
stallized at great depth from rocks of mostly sedimentary origin. The
plutonic igneous rocks intruded the metamorphic rocks also at great
depth in the form of molten magmas that crystallized into coarse-
grained, mostly granitic, rocks.
The metamorphic rocks of this complex are described below, from
supposedly oldest to youngest, together with their economic aspects.
(1) Gneiss, Precambrian ( ? ) . This rock is coarsely crystalline, lay-
ered ; formed by severe metamorphism probably from rocks that were
mostly sedimentary. The gneiss is exposed mainly in the San Ber-
nardino and San Gabriel Mountains. In some areas it contains layers
of coarse, white marble. In a few places the gneiss contains small
deposits of graphite and (or) radioactive minerals. The marble has
been quarried for roofing aggregate. (2) Pelona Schist, Precam-
brian ( ? ) . This is a highly foliated micaceous rock, recrystallized from
mostly sedimentary rocks. It is exposed in the San Gabriel and San
Bernardino Mountains. In places it contains a little soapstone (stea-
tite) and manganese ore. The schist is quarried for use as slab rock.
(3) Metasedimentary rocks. Paleozoic. These rocks are exposed mostly
in the San Bernardino Mountains where they rest unconformably on
gneiss, and consist of the Saragossa Quartzite overlain by the Furnace
Limestone. Gold was mined from shear zones in both these forma-
tions. The Furnace Limestone is quarried for industrial uses, includ-
ing cement manufacture. (4) Santa Monica Slate, pre-Cenozoic
(Triassic ( ? ) and Jurassic) . This rock, crystallized from shale, is ex-
posed only in the Santa Monica Mountains. It has been quarried for
slab rock. (5) Unnamed schist, pre-Cenozoic. This fine-grained fol-
iated rock crops out only on Santa Craz Island.
The plutonic igneous rocks of the basement complex include anorth-
osite and syenite, Precambrian, exposed only in the western San Gab-
riel Mountains and which contain small deposits of titaniferous iron
ore; small masses of quartz diorite, diorite, and gabbro, Mesozoic or
older; and large masses of granitic rocks, mostly quartz monzonite,
late Mesozoic.
The sedimentary and volcanic rocks rest unconformably on the base-
ment complex in the eastern part of the province. They underlie al-
most all the western part where they form an assemblage as thick as
40,000 feet. The stratigraphic formations that make up this assem-
blage are as shown on the columnar section (fig. 3) .
Formations of late Mesozoic age are marine sandstone, shale, and
conglomerate, as in the Coast Kange province. They include the
Franciscan Formation, thickness unknown, Espada Formation, at
least 7,000 feet thick, and Jalama Formation, about 3,500 feet thick,
all in the Santa Ynez Range, and "Chico" sandstone as thick as 3,000
feet in the Santa Susana Range. The Franciscan Formation contains
mafic volcanic flows and serpentine intrusions, in addition to sandstone.
68 MINERAL AND WATER RESOURCES OF CALIFORNIA
shale, and conglomerate, and is the host formation for deposits of
mercury.
The foniiations of Paleooene and Eocene age also are nearly all
marine sandstone, shale, and some conglomerate. The total thickness
is 8,000 feet or more. They are overlam by the mostly Oligocene
Sespe Formation comjx>sed of about 3,000 feet of nonmarine sedi-
ments. In the western Santa Ynez Range the Sespe grades laterally
Avestward into the marine Alegria Formation. All of these forma-
tions contain oil-producing sands. At the east end of Santa Clara
River Valley, the equivalent of the Sespe, or the Vasquez Fonnation,
contams volcanic flows, also small deposits of borate minerals at one
place.
The lower Miocene section, about 2,000 feet thick, is marine and
consists of the Rincon Shale Avith Vaqueros Sandstone at the base.
This sandstone is an important petroleum, producer along the Santa
Barbara coastal area. In the Santa Monica Momitains and eastward
this section consists of sandstone and shale of the Topaiiga Formation.
The marine middle Miocene to lower Pliocene section ranges from
2,000 to 7,000 feet thick. The basal part locally is com^wsed of vol-
canic flows that are thickest in the Santa Monica Mountains and
Channel Islands. The rest of the section is mostly siliceous and
diatomaceous shale of the Monterey (or Modelo), Puente, and Sisquoc
Fonnations, which locally contain sandstone. Diatomite is quarried
from the Monterey Shale and Sisquoc Formation in the western Santa
Ynez Mountains near Lompoc. In Ventura County, sandstones in
the Monterey (or Modelo) Shale produce large amounts of petroleum.
On the north side of the San Gabriel Momitains the section is composed
of the nonmarine Mint Canyon and Pmichbowl Formations.
The Pliocene section miderlies the Santa Clara River Valley and
Santa Barbara Channel where it consists of some 15,000 feet of marine
sandstone and shale of the Pico Formation. This formation is the
largest producer of petroleum in the province. Eastward the Pico
thins and in part grades laterally into the noimiarine Saugus For-
mation. The Pico Fonnation is overlain by about 2,000 feet of marine
Pleistocene sands of the Mudpit Shale and Santa Barbara Fonnation.
These grade laterally eastward into the nonmarine Saugus Formation.
The basement complex of the Transverse Range province, as in ad-
jacent provinces, is complex structurally as well as in rock distribu-
tion. It is composed of severely folded metamorT)hic rocks, complexly
intruded by the various plutonic igneous rocks.
This province has no delinite geologic bomidaries, but it is in large
part bomided on the north and south by major east-trending faults.
It is partly bomided by the southeast -trending San Andreas fault but
this and the San Gabriel fault to the southwest also transect it
diagonally.
Movement on the highly active San Andreas fault is horizontal.
The northeast block has shifted southeastward relative to the southwest
block, but simultaneously tliese blocks have been pushing against each
other with terrific force. As a result of this force the terrane of base-
ment complex that forms the San Bernardino Mountains was squeeze<:l
up like a wedge between the San Andreas fault and thrust faults to
the northeast. Similarly, the terrane of basement complex that fonns
MINERAL AND WATER RESOURCES OF CALIFORNIA 69
the San Gabriel Mountains and those to the northwest was squeezed
up between the San Andreas and the San Gabriel faults, but the
western part of this block was downwarped to form the Ridge basin,
which is filled with Tertiary sedimentary rocks. As a result of these
movements, the basement complex of all these ranges is severely
shattered, and the overlying Tertiary stratified rocks are severely
compressed into folds with east-trending axes.
The enormously thick stratigraphic section of mostly marine forma-
tions of Cretaceous and Cenozoic ages that underlies the western part
of the Transverse Range province accumulated in a great crustal
downwarp, or trough, that geologists call the Ventura basin. It was
submerged during Cretaceous and most of Cenozoic time when it
subsided continuously until more than 40,000 feet of sediments accumu-
lated in it. The axis of this trough followed the area now occupied
by the Santa Clara River Valley and westward into the Santa Barbara
Channel, which is the still-submerged part of this downwarp.
The strata along the flanks or margins of the Ventura basin have
been squeezed up by tremendous compressive forces to form the west-
ern Transverse Ranges. On the north flank, the Santa Ynez-Topatopa
Range was formed mainly by uplift and southward tilt of the strata
along the Santa Ynez fault at the north base of this range, and in part
by arching and thrust faulting of these strata. On the south flank,
the Channel Islands and Santa Monica Mountains were formed
largely by uplift and arching of the strata along a zone of east-
trending faults. Farther north on this flank the Santa Susana
Range was formed by arching of the strata, partly on two thrust faults.
Within or adjacent to these major upheavals, the strata are com-
pressed into numerous folds of east-trending axes. Many of these
folds near the axial part of the Ventura basin have entrapped the
petroleum and gas of this basin to form the oil fields of this province.
In summary it may be said that the physiographic features of the
Transverse Range province are the effect of an enormous amount of
north-south crustal shortening that resulted from tremendous com-
pressive forces. Part of tliis shortening is between the marginal
Santa Ynez Fault and the zone of faults through or adjacent to the
Channel Islands and Santa Monica Mountains. These are steep faults
transverse to the great San Andreas fault. Movements on these are
in part horizontal, in which the terrane north of the Santa Ynez fault
has been pushed westward, and the submerged terrane south of the
Channel Islands-Santa Monica fault has been pushed eastward, rela-
tive to tlie intervening transverse block.
Selected References
Bailey, T. L., and Jahns, R. H., 1954, Geology of the Transverse Range province,
southern California, in Geology of southern California : California Div. Mines
Bull. 170, chap. II, eontr. 6, p. 83-106.
Crowell, J. C, 1954, Strike-slip displacement of the San Gabriel fault, southern
Califoniia, in Geology of southern California : California Div. Mines Bull. 170.
chap. IV, contr. 6, p. 49-52.
Dibblee, T. W., Jr., 1950, Geology of southwestern Santa Barbara County, Cali-
fornia : California Div. Mines Bull. 1.50, 95 p.
Hoots, H. W., 1931, Geology of the eastern part of the Santa Monica Mountains,
Los Ajigeles County, California : U.S. Geol. Survey Prof. Paper 165-C, p. 83-134.
.lahns, R. H., 1940, Stratigraphy of the eastern Ventura basin, California, with a
70 MINERAL AND WATER RESOURCES OF CALIFORNIA
description of a new lower Miocene mammalian fauna from the Tick Canyon
Formation : Carnegie Inst. Washington Pub. 514. p. 14.5-194.
-. 1954, (ed), Geology of southern California: California Div. Mines Bull.
170, map sheets nos. 3, 4, 5, 6, 7, 8, 9, 10, 20, 25, 26, 27, 28, 29, 30, and 31 (sep-
arate author for each sheet) .
Kew, W. S. W., 1924, Geology and oil resources of a part of Los Angeles and
Ventura Counties, California : U.S. Geol. Survey Bull. 753, 202 p.
Noble, L. F., 1954, The San Andreas fault zone from Soledad Pass to Cajon Pass,
California, in Geology of southern California : California Div. Mines Bull,
170, chap. IV, contr. 5, p. 37-48.
Oakeshott, G. B., 1958, Geology and mineral deposits of the San Fernando
quadrangle, Los Angeles County, California : California Div. Mines Bull. 172,
139 p.
GEOLOGY OF THE PENINSULAR RANGES
(By G. L. Peterson, R. G. Gastil, and E. C. Allison, Department of Geology,
San Diego State College, San Diego, Calif.)
The Peninsular Ranges, bounded on the east by the Gulf of Cali-
fornia and Salton Trough and on the north by the Transverse Ranges,
constitute a distinctive physiographic and geologic province. Baja
(Lower) California, Mexico, the 800-mile-long peninsula tliat sep-
arates the eastern Pacific from the Gulf of California, constitutes the
bulk of the province, but only that relatively small portion north of
the international border is discussed here.
In general aspect, the province most closely i-esembles the Sierra
Nevada province and has had a somewhat similar geologic history.
Apparently the development of the province began with a thick
accumulation of predominantly marine sedimentary and volcanic
rocks. Ages of these oldest rocks are as yet poorly documented, but
late Paleozoic and early Mesozoic fossils have been reported, and
Jurassic fossils are locally present in the western part of the province.
Following this accumulation, in mid-Cretaceous time, the province
underwent a pronounced episode of mountain building. The thick
accumulation of sedimentary and volcanic rocks was complexly meta-
morphosed and invaded by igneous intrusions. These intrusive rocks,
the Southern Calif ornia batholith, now constitute the dominant terrain
of the province. A period of erosion followed the mountain-building
episode, and during Late Cretaceous and Cenozoic time, sedimentary
and subordinate volcanic rocks were deposited upon the eroded surface
of the batholithic and pre-batholithic rocks. These post-batholithic
rocks occur principally along the western and northern margins of the
province. Thus, in terms of geologic history, rocks of the province can
be subdivided into three general units: 1) pre-batholithic rocks,
2) the Southern California batholith, and 3) post-batholithic rocks.
Each of these gross rock units and its economic significance is outlined
below. Cenozoic faulting and changes of sea level relative to land
level added distinctive topographic features which are discussed on a
later page.
Pre-batholithic Rocks
Pre-batholithic rocks occur principally in the highlands or centrally
located part of the province. They occur on the western flank of the
batholith and as remnants in numerous areas within the batholith.
These metamorphic rocks are further divisible into two broadly differ-
ing types. The first and probably oldest type is more common in the
MINERAL AND WATER RESOURCES OF CALIFORNIA 71
central and eastern parts of the province. In general, this group of
rocks is a highly metamorphosed assemblage of schists, amphibolites,
(^uartzites, gneisses, and crystalline limestones. Evidence for the age
of this complex is scanty, but most investigators regard it as late Paleo-
zoic and early Mesozoic. (^rushed and broken stone, dimension stone,
and crystalline limestone (used in the manufacture of cement) are
important economic commodities. Other economic deposits derived
from these rocks are also associated with the batholithic rocks and are
discussed below.
A second assemblage of pre-batholithic rocks occurs on the western
side of the province, ajid principally occupies a narrow belt extending
down the coast from the Santa Ana Mountains to San Diego. In con-
trast to the first, tliis belt of rocks consists of the mildly metamorphosed
slates and argillites of the Bedford Canyon Formation and a thick
succession of volcanic and related rocks designated the Santiago Peak
Volcanics. Offsliore, on Santa Catalina Island, there is a small ex-
posure resembling tlie Franciscan Formation, a unit more character-
istic of the Coast Ranges. The entire Avesteni belt of metamorphic
rocks is apparently of Jurassic and Early Cretaceous age, as is indi-
cated by several recent fossil discoveries. Crushed stone, decorative
building stone, and pyrophyllite (used i:)rincipally as an insecticide
base) are apparently the only commodities now being obtained from
this belt of rocks.
The structural details of tlie pre-batholithic rocks are highly com-
plex, but individual rock units have a predominant northwesterly trend
and are generally inclined steeply to the southwest or northeast. This
persistent grain is disrupted in many areas, however, by igneous intru-
sions associated with the batholith.
Batholithic Rocks
The Southern California batholith constitutes the backbone and
dominant portion of the province, extending from near Los Angeles
southeastward approximately 1,000 miles to the southern extremity of
Baja California. Average widtli of outcrop in southern California is
approximately 70 miles. The }:)atholith is by no means a single homo-
geneous rock unit, but a complex series of intrusions and related meta-
morphic rocks. Various investigators have described, mapped, and
named numerous smaller rock divisions within the batholith. These
smaller divisions range widely in rock type including gabbros, tonal-
ites, granodiorites, and granites. Radiometric age determinations date
the filial consolidation of the batholith at 00 to 100 million years ago, in
mid-Cretaceous time.
A variety of mineral resources are associated with the ])atholithic
and pre-batholithic rocks. Ores of copper, gold, molybdenum, nickel,
silver, and tmigsten have been mined sporadically. Tlie deposits are
mostly low grade, however, and mining activity was greatest during
times of exceptional demand, such as during the world wars. Far
more important in recent years has been the production of crushed
and broken stone and dimension stone. Of the latter, several varieties
such as "black granite" (gabbro) and "gray granite" (quartz diorite
or granodiorite) are quarried at several localities and marketed for
industrial purposes and as decorative building or monument stone.
72 MINERAL AND WATER RESOURCES OF CALIFORNIA
Numerous pegmatite dikes cut across the earlier igneous and meta-
morphic rocks of the batholithic complex. The gem- and lithium mica-
bearing pegmatites of Kiverside and San Diego Counties are particu-
larly well known. These deposits have yielded numerous minerals
including pink and green tourmaline, garnet, quartz crystals, lepido-
lite, beryl, spodumene, topaz, and feldspar. These dikes have consti-
tuted one of the most important sources of gem and lithium minerals
in the United States.
Post-Batholithic Rocks
Sedimentary and subordinate volcanic rocks deposited on the eroded
surface of the batholithic and pre-batholithic rocks are confined princi-
pally to the coastal area of the province. In this report they are
further subdivided into two areas of outcrop for purpose of descrip-
tion. The first, and southernmost area consists of a narrow strip ex-
tending from Oceanside south to the International border. Post-
batholithic rocks of this area are almost entirely sedimentary and
consist of poorly consolidated, richly fossiliferous, and generally flat-
lying units of sandstone, shale, and conglomerate. Formations in-
clude, in ascending order, Rosario (Cretaceous), La Jolla and Poway
(Eocene), San Diego (Pliocene), and Sweitzer, Lindavista, and Bay
Point (Pleistocene) . IVIaterials used chiefly in the construction indus-
try (sand and gravel, clay, expansible shale, and specialty sands) are
extracted from these miits and constitute some of the most important
economic commodities of San Diego County at the present time. In
the past, minor amounts of placer gold have been obtained from some
of the Eocene gravels of this area.
North of Oceanside, the width of area covered by post -batholithic
rocks increases markedly and extends inland to the vicinity of Pomona
and northward to the Transverse Ranges. In this area, the Los An-
geles basin, sedimentary rock units are both more numerous and
individually thicker, and are more deformed than farther south. Ap-
parently this area was persistently do^vn warped and occupied by the
sea throughout much of Cenozoic time, and tectonically was more
comparable to the Transverse Ranges than to the remainder of the
Peninsular Ranges. As with the post -batholithic rocks to the south,
materials used in the construction industries are important economic
commodities, but in contrast, the Los Angeles basin is also well known
as one of the most important petroleum provinces on the western shore
of North America.
Post-batholithic volcanic rocks occur as minor units in the Los
Angeles basin, in areas south of Elsinore, and near Jacumba. Volcanic
rocks also occur on Santa Catalina Island and constitute the dominant
rock type of San Clemente Island. Economic significance of these
volcanic rocks is negligible at present.
Structure and Topography
Structurally, the province appears to be an uplifted and westward-
tilted block. The eastern flank is the highest and most rugged part,
with altitudes gradually decreasing toward the ocean. Cutting across
this large-scale pattern are numerous, large, northwest-trending faults.
MINERAL AND WATER RESOURCES OF CALIFORNIA 73
These faults subdivide the province into several subparallel blocks
AVhich are topographically expressed as northwest-trending ranges and
interv^ening valleys. The largest faults j)arallel the San Andreas fault
system and are probably closely related. A much smaller northeast-
trending set of faults appears to be associated with the major set. Ap-
parently the faults were active throughout much of Cenozoic time.
Activity to the present is indicated by recent warping and displace-
ments, by liot springs along the fault traces, and by seismic unrest in
the vicinity of many of the larger faults.
Distinctive topographic features of the coastal part of the province
include numerous bench-like surfaces developed w^hen the sea was at
higher levels. These marine terraces are abundant in certain tectoni-
cally active areas, such as near Palos Verdes. In other areas only three
main terraces have been developed. Many of the coastal cities of
southern California such as San Diego, Del Mar, and Oceanside are
located largely on these terraces.
Selected References
Allison, E. C, 1964, Geology of areas bordering Gulf of California, in van Andel,
T. H., and Shore, G. G., Jr., eds.. Marine geology of the Gulf of California : Am.
Assoc. Petroleum Geologists Mem. 3, p. 3-29.
Beal, C. H., 1948, Reconnaissance of the geology and oil possibilities of Baja
California, Mexico : Geol. Soc. America Mem. 31, 138 p.
Bushee, Jonathan, Holden, John, Geyer, Barbara, and Gastil, Gordon, 1963, Lead-
alpha dates for some basement rocks of southwestern California : Geol. Soc.
America Bull., v. 74, no. 6, p. 803-806.
Gray, C. H. Jr., 1961, Geology of the Corona south quadrangle and the Santa Ana
Narrows area ; Riverside, Orange and San Bernardino Counties, California :
California Div. Mines Bull. 178, p. 1-58.
Hanna, M. A., 1926, Geology of the La JoUa quadrangle, California : California
Univ, Dept. Geol. Sci. Bull., v. 16, no. 7, p. 187-246.
Hudson, F. S., 1922, Geology of the Cuyamaca region of California, with special
reference to the origin of the nickeliferous pvrrhotite: California Univ., Dept.
Geol. Sci. Bull., v. 13, no. 6, p. 175-152.
Jahns, R. H., ed., 1954, Geology of southern California : California Div. Mines
Bull. 170, 878 p.
Larsen, E. S., Jr., 1948, Batholith and associated rocks of Corona, Elsinore, and
San Luis Rey quadrangles, southern California : Geol. Soc. America Bull.,
V. 57, no. 3, p. 233-260.
Merriam, R. H., 1946, Igneous and metamorphic rocks of the southwestern part
of the Ramona quadrangle, San Diego County, California : Geol. Soc. America
Bull., v. 57, no. 3, p. 233-260.
Miller, W. J., 1946, Crystalline rocks of southern California : Geol. Soc. America
Bull., V. 57, no. 5, p. 457-542.
Silberling. N. J.. Schoellhamer, J. E., Gray, C. H., Jr., and Imlay, R. W., 1961,
Upper Jurassic fossils from Bedford Canyon Formation, southern California :
Am. Assoc. Petroleum Geologists Bull., v. 45, no. 10, p. 1,746-1,748.
Weber, F. H., Jr.. 1963, Geology and mineral resources of San Diego County,
California : California Div. Mines and Geology County Rept. 3, 309 p.
GEOLOGY OF THE SALTON TROUGH
(By W. B. Hamilton, U.S. Geological Survey, Denver, Colo.)
The Salton Trough is a desert- basin extending northwestward into
southern California from the Gulf of California. The trough is
bounded by mountains of Precambrian, Paleozoic, Mesozoic, and Ter-
tiary rocks, but is itself mostly a plain of low relief floored bj^ surficial
deposits. A region 85 miles long and up to 30 miles wide, which is
67-164 O — ^66 — pt. I 6
74 MINERAL AND WATER RESOURCES OF CALIFORNIA
most of the surface of the trough, is below sea level, dammed from
the Gulf by the delta of the Colorado River. The fluctuatino; surface
of the 30-mile-long Salton Sea is more than 200 feet below sea level.
The Salton Troujjh is filled by late Cenozoic sediments whose maxi-
mum tliickness, about 21,000 feet, is just south of tlie Mexican border
(Biehler and others, 1964). The stratigraphy of the valley fill, as
exposed in the deformed areas about the basin and as known from
well records, was described by Dibblee (1954). The sediments repre-
sent continuous deposition from late( 0 Miocene time to the present
and, except for the marine Imperial Formation low in the section, are
continental clastic strata. Fanglomerates, alluvial sands and silts,
and lacustrine silts and clays, interfinger complexly and have been
given various formation names by Dibblee (Borrego, Brawley, Cane-
brake, Mecca, Ocotillo, Palm Spring, Split Mountain). The lacus-
trine Borrego Fonnation contains thin strata of thenardite (sodium
sulfate) east of Salton Sea. Large deposits of gypsum occur just be-
low the Imperial Formation in Fish Creek Mountain west of El Centro.
Silicic and intermediate volcanic rocks are present locally in the upper
Cenozoic section.
Pre-Cenozoic crystalline rocks are exposed throughout the moun-
tains that border the trough and similar rocks presumably underlie the
Cenozoic sedhnents that fill it, but are exposed in the trough only in
several low uplifts along strike-slip faults. In the Mecca Hills, north
of the Salton Sea, anorthosite and gneiss of Precambrian age and
schist of probable Paleozoic age underlie Pliocene and Quaternary
sandstone and fanglomerate (Crowell, 1962, p. 26-29). Jurassic
(about 155 million years old) quartz diorite forms Superstition Moun-
tain, northwest of El Centro (Bushee and others, 1963). Undated
granitic and metamorphic rocks crop out in a small mass at the Mexi-
can border near the east edge of the trough (Strand, 1962) .
Five small extrusive rhyolite domes of Quaternary age protrude
throu.q-li the sediments of the trougli at the southeast end of the Salton
Sea (Kelley and Soske, 1936). The northeast line of the domes is
crossed by a northwest-trending line of hot springs, mud pots, and
mud volcanoes ("N^Hiite, 1955). Carbon dioxide at high pressure and
temperature is plentiful here in shallow subsurface reservoirs and is
produced commercially where it is found with a low Avater content
(White, 1955) . A mile-deep well drilled nearby for geothermal power
encountered very hot (about 600° F) brine containing about 33 percent
by weifflit of sodium, calcium, and potassium chlorides, and in addi-
tion lithium, barium, lead, silver, copper, and other metals in amounts
far higher than those known elsewhere in subsurface brines (White
and others, 1963). Commercial use of the brine and its geothermal
heat is to be expected once waste-disposal problems are solved.
The present Salton Sea has been maintained bv irrigation water
since it fonned in 1905-1906 when the Colorado Eiver broke into the
Salton Trough during floods. A higher stand of the Salton Sea, end-
ing only a few centuries ago, left wave-cut shorelines, lacustrine shells,
and locally travertine, about the basin to an altitude generally a little
above present sea level (e.g., Dibblee, 1954, pi. 2) .
Wind-blown sand fomis deposits throughout much of the Salton
Trough. By far the largest are the Sand Hills, a belt ahout 5 miles
MINERAL AND WATER RESOURCES OF CALIFORNIA 75
wide of dunes trendintj northwestward for 40 miles from the Mexican
border in the eastern part of the trough.
The Salton Trough is the northern extension of the structural de-
pression of the Gulf of California. Continental crust, lacking beneath
the deep southern part of the Gulf, thickens gradually northward
along the northern part ; it is about 20 miles thick at the International
border, and 25 miles thick at the north end of the Salton Trough
(Biehler and others, 1964). The structure of the Salton Trough is
dominated by the several right-lateral strike-slip faults of the San
Andreas system — San Jacinto, Imperial, San Andreas proper, etc, —
which trend obliquely into it from the northwest. The faults present
an en echelon array, stepping to the right; individual faults strike
more westerly than does the fault system as a whole, or than does the
gulf depression into which the system trends. Right-lateral surface
offsets within the Salton Trough occurred during earthquakes of 1857
(San Andreas fault; the offset sector was mostly northwest of the
trough, but probably extended into it), 1934 (San Jacinto fault, in
Mexico; Biehler and others, 1964), and 1940 (Imperial fault). De-
formation of the region is continuing at a very rapid rate, and the
southwest margin of the trough moved several feet northwestward,
relative to the northeast margin, Avithin the short period 1941-1954,
without further surface faulting (Whitten, 1956, fig. 3). Future se-
vere earthquakes accompanying surface faulting are to be expected.
Previous late Quaternary right-lateral offsets along the San An-
dreas fault in the trough are indicated by displaced drainage lines and
by the tight, locally isoclinal folds with steeply plunging axes of Pleis-
tocene and alluvial sediments adjacent to the fault. Total Cenozoic
displacement has been enormous: distinctive middle Eocene strata are
displaced 180 miles along it, from the Orocopia Mountains at the
northeast edge of the Salton Trough to the Tejon region (Crowell,
1962) ; displacement of mid-Cretaceous granitic rocks has been 300
miles (c.f. Hill and Dibblee, 1953). The Gulf of California appar-
ently opened as the Peninsula of Baja California pulled obliquely
away from the mainland during Cenozoic time, and the Salton Trough
probably formed by tensional thinning of the continental crust accom-
panying this motion (Hamilton, 1961) .
The folding and minor faulting, like the major strike-slip faulting,
demonstrate clockwise torsion within the trough throughout late Ceno-
zoic time (Dibblee, 1954, p. 28). The primary right-lateral faults
trend northwestward. Minor left-lateral faults trend northeastward,
and probably represent adjustments between blocks dragged by the
major faults. Folds in the Cenozoic sediments trend mostly eastward
and are en echelon, along or near both the major and minor fault zones.
Selected References
Biehler, Shawn, Kovach, R. L., and Allen, C. R., 1964, Geophysical framework
of northern end of Gulf of California structural province : Am. Assoc. Petro-
leum Geologists Mem. 3, p. 126-143.
Bushee, Jonathan, Holden, John, Geyer, Barhara, and Gastil, Gordon. 1963,
Lead-alpha dates from some basement roclcs of southwestern California :
Geol. Soc. America Bull., v. 74, no. 6. p. 803-806.
Crowell, J. C, 1962. Displacement along the San Andreas fault. California :
Geol. Soc. America Spec. Paper 71, 61 p.
76 MINERAL AND WATER RESOURCES OF CALIFORNIA
Dibblee, T. W., Jr., 1954, Geology of the Imperial Valley region, California, [Pt.
2] in Chap. 2 of Jahns, R. H., ed.. Geology of southern California : California
Div. Mines Bull. 170, p. 21-28.
Hamilton, Warren, 1961, Origin of the Gulf of California : Geol. Soc. America
Bull., V. 72, no. 9, p. 1,307-1,318.
Hill, M. L., and Dibblee, T. W., Jr., 1953, San Andreas, Garlock, and Big Pine
faults, California : Geol. Soc. America Bull., v. 64, no. 4, p. 443-4.58.
Kelley, V. C, and Soske, J. L., 1936, Origin of the Salton volcanic domes, Salton
Sea, California : Jour. Geology, v. 44, no. 4, p. 496-509.
Strand, R. G., 1962, Geologic map of California, San Diego-El Centro sheet:
California Div. Mines and Geology, scale 1 : 250,000.
White, D. E., 1955, Violent mud-\^olcano eruption of Lake City Hot Springs,
northeastern California : Geol. Soc. America Bull., v. 66, no. 9, p. 1,109-1,130.
White. D. E., Anderson, E. T., and Grubbs, D. K., 1963, Geotherraal brine well—
mile-deep drill hole may tap ore-bearing magmatic water and rocks under-
going metamorphism : Science, v. 139, no. 3,558, p. 919-922.
AVhitten, C. A.. 1956, Crustal movement in California and Nevada : Am. Geophys.
Union Trans., v. 37, no. 4, p. 393-398.
MINERAL RESOURCES
INTRODUCTION
(By J. P. Albers, U.S. Geological Survey, Menlo Park. Calif.)
The economic value of a mineral resource is determined by the cost
of mining and processing, cost of marketing, including transportation
to market, and by the demand for the commodity. Costs and demand
vary with fluctuations in local or national economy, advances in the
technological fields of exploration and exploitation, and increases in
requirements by industry and the expanding population. A resource
that cannot be developed profitably today may become the basis for a
profitable enterprise in the future because of these constantly changing
sociologic, technologic, and economic factors.
A distinctive characteristic of mineral economics is that once a min-
eral resource is exhausted it cannot be replaced. This creates problems
both in concepts of conservation and execution of resource develop-
ment. For this reason, efficient development, intelligent use, and con-
tinuing search for new or substitute mineral resources are of impor-
tance to economic growth. Advances in the techniques of exploration
and processing of mineral resources have been successful in meeting
the most fundamental needs of the nation's economy to date. How-
ever, with depletion of high-grade deposits, it will become necessary
to locate and develop deposits that are lower grade, particularly those
that give promise of yielding more than one mineral commodity, others
that are deeply buried, and still others that are farther from estab-
lished markets.
The accumulation of a mineral or rock to form an economic deposit
is the result of one or more specific geologic processes, and therefore
each type of mineral resource is limited in distribution to certain geo-
logic environments. Thus, the occurrence of many individual mineral
commodities in California is more or less restricted to specific geologic-
geomorphic provinces. Deposits of many metals, particularly base
and precious metals, are concentrated in dej^osits by aqueous solutions
emanating from large deep-seated bodies of magma. Deposits of this
origin commonly occur as veins that fill fractures in the host rock, or
occur as a metasomatic replacement of the host rock. The primary
deposits of gold, copper, silver, tungsten, and molybdenum in the
Sierra Nevada region originated as emanations of solutions from the
more silicic, lighter-colored f acies of granitic rocks of the Sierra Ne-
vada batholith. However, it is important to note that these metallifer-
ous deposits are restricted to the sedimentary and volcanic rocks that
were invaded by the batholith, and that the batholith itself is barren.
Similar conditions prevail in the Klamath Mountains where deposits
of base and precious metals are found in rocks invaded by granitic
plutons, and in the Mojave Desert and Great Basin where iron, rare-
earths, and base-metal deposits are found principally as a replacement
77
78 MINERAL AND WATER RESOURCES OF CALIFORNIA
of carbonate rocks near igneous contacts. Such commodities as talc,
pyrophyllite, kyanite, and andalusite, are also closely related to igne-
ous rocks, being the product of the metamorphism of invaded country
rock by the heat and emanations from the igneous intrusion.
Other mineral comLmodities found in close association with deep-
seated igneous rocks include mica, feldspar, gemstones, chromite, as-
bestos, and nickel. Tliese are commonly in the igneous rocks them-
selves rather than in the invaded country rock. Mica, feldspar, beryl,
and many gemstones are most commonly extracted from pegmatites,
irregular dike-like bodies of very coarsely crystalline igneous rock in-
truded into igneous rock of finer grain size. However, mica and feld-
spar also are extremely abundant in many ordinary' igneous and meta-
rnorphic rocks and in some localities are produced commercially from
the bulk mining of these rocks. Chromite, asbestos, and nickel are
associated with dark mafic and ultramafic igneous rocks — the first two
commodities with peridotite and serpentinite, and the latter with
peridotite, serpentinite, and gabbro. Chromite crystallized contem-
]^oraneously with the ultramafic rock, and deposits of this mineral
formed by a process called magmatic segregation. Asbestos occurs as
small vein-like fracture fillings mostly in ultram.afic rock that have
been serpentinized, and nickel is present in sulfide minerals and also
indigenously in very small amounts in ultramafic rocks.
Mercuiy deposits are found chiefly in regions of extensive Cenozoic
volcanic and tectonic activity. The most important deposits in Cali-
fornia, however, are found hi silica-carbonate rock, a hydrothermal
alteration of serpentine found mainly in the Franciscan Formation of
the Coast Ranges. Nevertheless, cinnabar, which replaces the silica-
carbonate rock, is thought to be a product of volcanic activity. In
places in California, the mercury mineral cimiabar is being deposited
around presently active hot springs.
Mineral fuels such as petroleum, natural gas, peat, and asphalt, are
products of organic decay and recomposition in a sedimentary envi-
romnent, and these resources are therefore in sedimentary rocks. In
California, mineral fuels are best preserved in thick sedimentary de-
posits of late Mesozoic and Tertiary age found in the San Joaquin, Los
Angeles, and other sedimentary basins. Diatomaceous earth results
from accumulation of the siliceous shells of microscopic plants in either
a marine or continental sedimentary environment; commonl}^ it is in
sedimentary deposits that are in close association with volcanic rocks.
Hence de]X)sits of diatomaceous earth occur not only in upper Meso-
zoic and Tertiary sedimentary^ terranes such as the southern Coast
Ranges but also in volcanic terranes such as the Modoc Plateau.
Some of California's most important mineral commodities are the
saline minerals — boron and borax, bromine, calcium chloride, potash,
salt, sodium carbonate, and sodium sulfate. Deposits of these com-
modities were formed in two large saline lakes that developed during
late Cenozoic time mainly in closed basins in the Great Basin province.
They are the product of evaporation of waters richly charged with
mineral constituents. Gypsum and anhydrite are more widely dis-
tributed but somewhat less soluble products of evaporation that formed
in many marine and continental basins in the State.
The "purpose of this generalized and incomplete review of Cali-
fornia's mineral resources is to demonstrate how the occurrence of
individual resources or groups of resources is restricted to certain
MINERAL AND WATER RESOURCES OF CALIFORNIA
79
geologic environments within the State. A more detailed summarj^ of
the resources on a commodity-by-commodity basis is given in the
succeeding pages.
California's production of the various mineral commodities during
1963 and 1964, the latest years for which figures are available, is given
in table 3.
Table 3. — Mineral production, in California,^ 1963 and. 196^^
Mineral
Asbestos
Barite (crude)
Boron minerals
Calcite (optical grade) pounds..
Cements . 376-pound barrels,.
Clays 3
Copper (recoverable content of ores, etc.)
Feldspar long tons.
Geni stones
Gold (recoverable content of ores, etc.). -.troy ounces..
Gypsum
Lead (recoverable content of ores, etc.)
Lime
Magnesian compounds from sea water and bitterns
(partly estimated) MgO equivalent..
Mercury 76-pound flasks..
Mica, scrap
Natural gas million cubic feet..
Natural gas liquids:
Natural gasoline and cycle products
thousand gallons..
Lp gases do
Peat
Petroleum (crude) thousand 42-gallon barrels..
Pumice, pumicite and volcanic cinder
Salt (common)
Sand and gravel
Silver (recoverable content of ores, etc. )--troy ounces..
Stone «
Sulfur ore long tons..
Talc, pyrophyllite, and .soapstone.
Wollastonite
Zinc (recoverable content of ores, etc.)...
Value of items that cannot be disclosed: Bromine, cal-
cium chloride, carbon dioxide, masonry cement (1963),
clays (ball and fuller's earth) 1964, coal (lignite), dia-
torhite, iodine, iron ore, lithium minerals, molyb-
denum, perlite, platinum-group metals, potassium
salts, rare-earth metals, sodium carbonate, sodium
sulfate, steam (natural), tin, tungsten concentrate,
uranium, and values indicated by footnote '.
Total.
1963
Short tons
(unless
otherwise
stated)
19, 591
5,082
700, 183
1,
46, 278, 000
3, 395, 000
916
75, 516
(5)
86, 867
756, 000
823
487,000
82, 397
13, 592
977
646, 486
715, 303
393, 503
39, 873
300, 908
460, 000
1, 716, 000
112, 185. 000
157, 000
37, 977, 000
785
120, 452
3,000
101
Value
(thousands)
$1,547
31
54, 981
147, 656
8,031
564
200
3,040
4,222
178
8,932
6,135
2,575
14
189, 420
54, 188
17, 329
450
746, 232
2,017
(<)
128, 178
200
58, 253
4
1,427
28
23
90, 366
1,526,241
1964
Short tons
(unless
otherwise
stated)
55, 041
5,604
776,000
4
47, 204, 000
3, 651, 000
1,035
102, 264
(5)
71, 026
1,893,000
1,546
577, 000
94, 739
10, 291
w
664. 051
720, 373
352, 614
35, 391
300, 009
443, 000
1, 525. 000
112,995,000
172, 000
45, 805, 000
520
132, 601
3,625
143
Value
(thousands)
$4, 419
45
60, 871
2
149, 933
8,196
675
(«)
200
2,486
4,539
405
10,312
7,143
3,240
(*)
198, 551
54, 088
15, 893
443
729, 022
1,937
129, 333
222
63,566
3
1,631
36
39
113,280
1,561,033
' Production as measured by mine shipments, sales, or marketable production (including consumption
by producers) .
- Excludes masonry cement included with "Value of items that cannot be disclosed."
3 Incomplete figure. Ball clay and fuller's earth included with items that cannot be disclosed.
* Withheld to avoid disclosing company confidential data.
* Weight not recorded.
» Includes slate.
Source: U.S. Bureau of Mines.
ALUMINUM
(By G. B. Cleveland, California Division of Mines and Geology, Los Angeles,
Calif.)
Aluminum, the second most abundant metal in the earth's crust, is
found in nearly all rocks. Only under special geologic conditions,
however, does it occur in large high-grade deposits that can be eco-
nomically worked as a source of the metal. At present, the only im-
80 MINERAL AND WATER RESOURCES OF CALIFORNIA
portant ore of aluminum is bauxite. The principal domestic deposits
of bauxite are in Arkansas, Georo-ia, Alabama, .and Mississippi. These
contain less than one percent of the world's reserves, and many cannot
compete either in quality or price with foreign imports. In 1963, the
domestic deposits supplied only about 12 percent (1,525,000 long tons)
of the bauxite consumed in the United States. The balance ^.fibout
11,318,000 long tons) was drawn principally from the Caribbean
islands of Jamaica, Haiti, and the Dominican Eepublic, and from
the Guianas. The IJnited States ranks first in the production of pri-
mary aluminum metal, supplying about 2,313,000 tons of the world
total of about 6,095,000 tons in'l963.
Aluminum has an extremely wide variety of uses. Most of them
are in products where light weight or resistance to corrosion are im-
portant— military equipment, industrial, farm and residential building
materials, automobiles, home appliances, and materials and containers
It is also used in industrial chemicals, and electrical wire.
Bauxite is a colloidal mixture composed of various proportions of
the minerals gibbsite (A1(0II)3) and the dimorphic forms boehmite
and diaspore, both (AIO(OH)). Common impurities are rutile,
siliceous minerals such as kaolinite and quartz, as well .as the iron
oxides — limonite, hematite, and goethite — and the carbonate minerals
calcite, magnesite, and siderite. Bauxite is gray, cream, yellow, dark
red, or earthy brown, is normally pisolitic or oolitic and generally has
a mottled appearance. Bauxite is a residual product formed by the
deep weathering of aluminous rocks under tropical conditions, and
is commonly a constituent of lateritic soils. All domestic deposits are
Eocene in age.
The known occurrences of bauxite in California are limited to small
deposits which are associated with fire clay. None of these deposits
has proved large enough to haA'e been developed as a commercial source
of aluminmn; nor has this metal been recovered from any raw mate-
rial mined in California. However, other alumina-rich deposits, prin-
cipally the large anorthosite bodies in the southern part of the State
and the alumina-rich clays, constitute potential resources that may
eventually yield aluminum on a commercial basis.
The only large anorthosite bodies known in California are exposed
in the western San Gabriel Mountains of southern California and have
a combined outcrop area of about 50 square miles. The San Gabriei
Mountain anorthosite is composed of calcic andesine (97 percent)
with small amounts of apatite and zircon.
Although California contains no known deposits of clay that com-
pare in alumina content with the high-alumina (40 percent and above)
or diasporic clays (50 j^ercent or more alumina), some of the State's
fire clay can be classified as alumina-rich clay. The alumina-rich fire
clays from California deposits range from about 30 to 40 percent
alumina. These deposits are in the Eocene lone Fonnation which
occurs alone: the western foothills of the Sierra Nevada, the Paleocene
Silverado Formation exposed in the Alberhill-Corona area of River-
side Countv, and in the Eocene Tesla Formation in eastern Alameda
County. These clav beds vary in their alumina content, and the higher
grade material would have to be selectively mined.
Aluminum has been produced experimentally or on a small-scale
commercial basis from anorthosite, high-alumina clays, alunite, neph-
eline syenite, leucite, andalusite, and aluminous shales. When bauxite
MINERAL AND WATER RESOURCES OF CALIFORNIA 81
reserves become depleted, one or more of these materials may be de-
veloped on an economic basis.
Selected References
Allen, V. T., 1929. The lone Formation of California : California Univ., Dept.
Geol. Sci. Bull., v. 18, no. 14, p. 347-448.
Cleveland, G. B., 1957, Almninuni. in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176. p. 29-33.
, 1957. Clay, in Mineral commodities of California : California Div. Mines
Bull. 176, p. 131-152.
Dietrich, W. F., 1928. Clay resources and the ceramic industry of California:
Oalifoniia Div. .Alines Bull. 99, 383 p.
Higgs, D. v.. 1954. Anorthosite and related rocks of the western San Gabriel
Mountains, southern California : California Univ. Pub. Geol. Sci., v. 30, no. 3,
p. 171-222.
Lundquist, R. V., 1963, Recovery of alumina from anorthosite, San Gabriel Moun-
tains, California, using lime soda sinter process : U.S. Bur. Mines Kept. Inv.
6288.
Oake.shott, G. B., 1958, Geology of the San Fernando quadrangle, Los Angeles
County, California : California Div. Mines Bull. 172. 147 p.
Stamper, J. W., 1964. Aluminum: U.S. Bur. Mines Minerals Yearbook 1963, p.
207-234.
U.S. Bureau of Mines. 1953, Materials survey, bauxite : U.S. Bur. Mines, 13
chapters (loose leaf), various pagings.
Williams, L. R., 1965. Alumina and bauxite, in Mineral facts and problems : U.S.
Bur. Mines Bull. 630.
ANTIMONY
(By Q. A. Aune. California Division of Mines and Geology, Redding, Calif.)
Antimony is a brittle, silver-white metal with a melting point of
630.5 °C. Antimony metal has the property of expanding when cooled
and of hardening certain other metals when alloyed Avith them. The
effect of antimony in lead alloys is to add stiffness and physical
strength, to resist chemical action, and to make sharp, accurate cast-
ings. In nonmetallic compounds, it may be used as an opacifying
agent or as a pigment. Certain antimonial compounds have fire-
extinguishing characteristics which account for the bulk of antimony
consumption during wartime. The nearly complete dependence of the
United States on foreign su])ply as shown in figure 5, and the diversity
of its major uses earn antimony's classification as a strategic mineral.
A substantial portion of metallic antimony produced in the United
States is secondary antimony reclaimed from scrap metal (fig. 5). In
recent years, production of antimonial lead has consumed roughly
18,000 tons of antimony annually, over two-thirds of this from sec-
ondary antimony, and most of it used in auto batteries. Production
of bearing metal, cable covering, sheet and pipe, solder, and type metal
has also relied heavily on secondary antimony.
Antimony deposits may be classified in two types. The mineralogi-
cally simple type consists dominantly of antimony minerals in a sili-
ceous gangue, commonly with a little pyrite and in places small
quantities of other metal sulfides. The original antimony mineral is
stibnite (antimony sulfide) or, rarely, native antimony. Where ex-
posed to oxidation, the original minerals are converted to antimony
oxide. Although most of the world's production is from deposits of
the simple type, most of the antimony mined in the United States is,
for economic reasons, from deposits of the complex type : ores mined
primarily for lead, gold, silver, quicksilver, zinc, or tungsten, with
antimony as a by-product.
82
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA 83
Most of the antimony deposits of California, as shown on figure 6,
are of the simple type — small ore bodies that commonly show struc-
tures characteristic of epithermal deposits — fissure fillings, irregular
disseminations in vugs or "pockets" and breccia, and haphazard frac-
ture control.
The Stayton district in San Benito and Merced Counties is the larg-
est antimony mining district in California, although production has
been small, limited to perhaps 500 tons of antimony metal, none since
World War II. Antimon}^ occurs as stringers and cavity fillings of
tarnished stibnite which are localized in numerous north-northwest-
trending fault zones in Tertiary basalts and tuffs. In late 1949 and
throughout 1950, the Cordero Mining Co. of Palo Alto and the U.S.
Bureau of Mines prospected the Quien Sabe mine, a principal deposit
of this district, and revealed a moderate tonnage of ore averaging
three percent antimony.
The Wildrose Canyon deposit in the Panamint Range, Inyo County,
has been the principal past producer in California. Antimony oxides
and stibnite occur in blanket -type breccia deposits in schists, and as
fissure fillings in quartz veins.
At the Transportation (Old Dependable) deposit, near the base of
the Panamint Range a few miles east of the Wildrose Canyon deposit,
stibnite and antimony oxides occur in small, scattered masses in shale
overlying limestone. Other deposits in Inyo County occur at the Hill-
top, Rocket, and Darwin mines on the west slope of the Argus Range,
and the Bishop mine on the east slope of the Sierra Nevada near
Bishop.
A number of deposits have been worked for antimony in Kern
County. Most of these deposits consist of stibnite and quartz in veins
along shear zones in granodiorite or quartz diorite. The largest de-
posit of this type is the San Emigdio (Antimony Peak) deposit in
southeastern Kern County. Calcite, pyrite, and antimony oxides are
also present. The deposit was mined intermittently from 1882 to 1892,
during World War I, and most recently in 1940-1941.
Deposits at Antimony Flat, eastern Kern County, consist of small
nodules and clusters of radiating stibnite blades disseminated along
poorly exposed steeply dipping quartz veins in granodiorite. Stib-
nite occurs in quartz veins in silicified andesitic rock at the Mammoth
Eureka mine 17 miles east of Caliente in east-central Kern County;
this mine was the source of an undetermined quantity of antimony ore
during World War I. At the Tom Moore mine, aggregates of bladed
and massive stibnite and native antimony occupy a quartz vein in a
shear zone in metamorphic rocks. At the Jenette-Grant mine, stib-
nite occurs with quartz along a limestone-schist contact.
In the Atolia district, near the west border of San Bernardino
County, stibnite is locally present in subordinate proportions in veins
in quartz monzonite. Mineralogy is complex. Chalcedony, quartz,
scheelite, and carbonates of calcium, iron, and magnesium are princi-
pal minerals, with cinnabar also locally present. At the Desert Anti-
mony (Wade) deposit in the Mountain Pass area, eastern San Bernar-
dino County, quartz-stibnite-barite-calcite veins occur in granitic
gneiss.
Total inferred California reserves of antimony metal from ore esti-
mated to contain greater than one percent antimony, assuming such
"ore" could be economically worked, would be on the order of only 15
to 20 thousand tons, a small amount compared to America's annual
84
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OP CALIFORNIA 85
needs, and most of this tonnage is in the Stayton district. Many of
the deposits are largely "high-graded" or worked out. Any large
tonnage developments probably must come from new deposits. Such
new deposits, if present, would seem most likely to occur in areas
favorable to epithermal deposition. Such areas are most likely to
occur ill the Great Basin provmce and the eastern margin of the Sierra
Nevada. Somewhat lesser possibilities are in the central Coast Range
and eastern Klamath Mountain areas.
Selected eefebences
Bailey, B. H., and Myers, W. B., 1M2, Quicksilver and antimony deposits of the
Stayton district, California : U.S. Geol. Survey Bull. 931-Q, p. 405-434.
, 1949, Quicksilver and antimony deposits of the Stayton district, Califor-
nia : California Div. Mines Bull. 147, p. 37-56.
Goldman, H. B., 1957, Antimony, in Mineral commodities of California : Califor-
nia Div. Mines Bull. 176, p. 35-44.
Jermain, G. D., and Ricker, Spangler, 1949, Investigations of Antimony Peak.
Kern County, California : U.S. Bur. Mines Rept. Inv. 4505.
Lesemann, R. H., 1965, The changing pace and pattern in the business of min-
ing— antimony : Eng. Min. Jour., New York, v. 166, no. 2, p. 129-131.
Moulds, D. E., 19&4, Antimony, in U.S. Bur. Mines Minerals Yearbook 1963, v. I,
p. 235-244.
Norman, L. A., Jr., and Stewart, R M, 1951, Mineral resources of Inyo County :
California Jour. Mines and Geology, v. 47, no. 1, p. 28-29, 36-37.
Troxel, B. W., and Morton, P. K., 1962, Mines and mineral resources of Kern
County, California : California Div. Mines and Geology County Rept. 1, p.
54-59.
U.S. Bureau of Mines, 1965, Antimony, in Mineral facts aiid problems: U.S. Bur
Mines Bull. 630, preprint, 10 p.
White, D. E., 1940, Antimony deposits of the Wildrose Canyon area, Inyo Countv,
California : U.S. Geol. Survey BuU. 922-K, p. 307-325.
White, D. E., 1962, Antimony in the United States : U.S. Geol. Survey Mineral Inv.
Resources Map MR-20.
Wiebelt, F. J., 1956, Quien Sabe antimony mine, San Benito County, OaUfomia :
U.S. Bur. Mines Rept. Inv. 5192.
Wright, L. A., Stewart, R. M., Gay, T. E., and Hazenbush, G.C., 1953, Mines and
mineral deposits of San Bernardino County, California : California Jour. Mines
and Geology, v. 49, nos. 1-2, p. 59-60.
ARSENIC
(By Q. A. Aune, California Division of Mines and Geology, Redding, Calif.)
Arsenic is produced as a by-product of copper and lead smelting
and in the recovery of gold and silver. It is recovered only in the
form of arsenious oxide (white arsenic), as no metallic arsenic has
been produced in the United States since about 1950. The United
States ranked as a major producer and consumer of arsenical products
in 1964. Other im])ortant producing countries in the free world in-
clude Sweden, Mexico, and France. No domestic ores are mined ex-
clusively for arsenic. The first recorded production of white arsenic
in the United States was in 1901. Arsenic is used for manufacturing
calcium and lead areenate insecticides and herbicides, in chemicals
for wood preservation, and is added to lead shot and glass. A small
amount is used in the recently developed solid state masers and
lasers.
The most common occurring arsenic-bearing minerals are the sul-
fides arsenopyrite, realgar, and orpiment. Arsenopyrite is commonly
associated in hypothermal vein deposits with the ores of tin, nickel,
cobalt, silver, and gold, and with pyrite, chalcopyrite, galena, and
86 MINERAL AND WATER RESOURCES OF CALIFORNIA
sphalerite in mesothermal deposits. Realgar and orpiment occur in
epithermal deposits with the ores of silver and antimony and in de-
posits formed by sublimation from hot springs.
In the early 1920's, California deposits were mined principally for
their arsenic content at Grass Valley, Nevada County ; at the Contact
mine in Kem County; and at the Black Momitain prospect in San
Diego Coimty.
Arsenic, principally in the mineral arsenopyrite, has a widespread
occurrence in the ore deposits of California, but at present is of doubt-
ful commercial interest in any California deposit. It is especially
abundant in the arsenopyrite-bearing silver ores of the Randsburg
district in Kern and San Bernardino Counties, and in the arseno-
pyrite-bearing gold ores of the Alleghany district in Sierra County
and the Mother Lode of the Sierra Nevada. Arsenopyrite and sulf-
arsenides are also present in the base-metal ores of the Mojave Desert,
the Sierra Nevada foothills, and the Shasta mining district.
Since 1924, large quantities of byproduct arsenic available for im-
port from Mexico have held prices down. More recently many uses
of arsenic as a toxic agent have fallen off with the advent of organic
compounds such as DDT. These competitive conditions have rendered
California arsenic mining unprofitable, and the closing of nonferrous
metal mines, from which arsenic might be recovered as a by-product,
has terniinated production in the State.
Sbxected References
California Agricultural Exi>eriment Station, 1954, Herbicidal properties of arsenic
trioxide : Calif. Agr. Expt. Sta. Bull. 7.39, 28 p.
Goodwin, J. G., 1957, Arsenic, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 45-48.
McMahon, A. D., 1964, Arsenic, in U.S. Bur. Mines 1963 Minerals Yearbook, v. I,
p. 24.5-249.
Sayre, R. H., 1924, Arsenical ore deposits in the United States : Eng. Min. Jour.,
V. 118, p. 929-932.
U.S. Bureau of Mines, 1965, Arsenic, in Mineral facts and problems: U.S. Bur.
Mines Bull. 680, preprint, 6 p.
ASBESTOS
(By S. J. Rice, California Division of Mines and Geology, San Francisco, Calif.)
Uses and Economic Importance
Asbestos is one of the few important nonmetallic minerals that is
largely imported from foreign sources. Of the 790,000 tons of asbestos
used in the United States in 1964, only about 100,000 tons were pro-
duced from domestic deposits. Most of the remainder was imported
from Canada.
Certain grades of asbestos are indispensable to the construction and
transportation industries, and all grades occupy important places in
the general industrial economy. Most of the important uses of asbes-
tos are based on the fact that it has physical characteristics similar
to those of organic fibers, yet it is both noncombustible and non-
corrosive. These physical properties are summarized in table 4. As
used in the manufacture of numerous products, asbestos acts as a
reinforcing agent or as a friction or insulation material. The princi-
pal use is in the manufacture of asbestos-cement products such as pipe.
MINERAL AND WATER RESOURCES OF CALIFORNIA
87
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88 MINERAL AND WATER RESOURCES OF CALIFORNIA
shingles, wallboard, and corrugated sheets. Large quantities also are
used in the manufacture of vinyl and asphalt floor tiles, friction
materials such as clutch facings and brake bands, insulation materials,
and gaskets. Small amounts of the spinning grades of strong-fiber
varieties are woven into asbestos fabrics for various special uses.
Mineralogy and Geologic Occurrences
The word asbestos is not a mineral name, but a term applied to
several naturally fibrous minerals that are used primarily because of
their fibrous characteristics. These minerals include chrysotile, cro-
cidolite, amosite, anthophyllite, and tremolite.
Chrysotile
Chrysotile is the most important asbestos mineral, accounting for
more than 90 percent of the world's asbestos production. Chrysotile
fibers of good quality are silky, highly flexible, and have a tensile
strength somewhat greater than that of silk.
Chrysotile occurs only in seri:)entine, a fine-grained rock composed
almost entirely of hydrous magnesium silicate minerals similar to
chrysotile in composition. Almost all masses of serpentine contain
chrysotile, most commonly in cross-fiber veins that rarely are more
than half an inch thick. In places, however, the fibers lie along faults
or shear planes and are not so apparent. Only rarely is chrysotile
sufficiently abundant in the rock to constitute an asbestos ore body.
Most of the chrysotile fibers in any deposit are very short (less than
one-sixteenth of an inch long), and clean extraction of the asbestos
requii-es complicated and expensive milling equipment, so a large vol-
ume of fiber-rich rock is required for a commercially valuable ore
body.
About 40 percent of the world production of chi-ysotile comes from
cross-fiber deposits in a relatively small district in the province of
Quebec, Canada. The discovery of these rich deposits in 1877 laid
the foundation of the modem asbestos industry. Substantial amounts
of chrysotile are produced from similar deposits in the U.S.S.R. and
Africa.
Amphibole asbestos
Amphibole asbestos is a general term for all varieties other than
chrysotile. These are all members of an exceedingly common group
of rock-forming silicate minerals characterized by perfect prismatic
cleavage. Only a few of the amphibole minerals, principally those
that are aluminum-poor, become sufficiently fibrous to be used as as-
bestos. In approximate order of economic importance, these are
crocidolite, amosite, anthophyllite, and tremolite.
The principal source of crocidolite — blue asbestos — is the Union of
South Africa, but lesser quantities are produced in Australia and
Bolivia. Commercial deposits of this variety have not been found in
California. Amosite, a yellowish-gray, long-fiber variety, is produced
in Africa, and has not been found else wliere. Both of these varieties
oc^ur as cross-fiber veins in metamorphosed sedimentary rocks rich in
silica and iron, and both have strong fibers.
Most anthophyllite asbestos occurs in massive deposits derived by
metamorphism of peridotite. The fibers have no preferred orienta-
tion, but are arranged in bundles of varying sizes oriented at random.
MINERAL AND WATER RESOURCES OF CALIFORNIA
89
Deposits of this type are mined in Finland and North Carolina. In
(California, long-fiber anthophyllite occurs as veins along; faults in ser-
pentine; the fibers are oriented roughly parallel to the walls of the
veins. The latter mode of occurrence is characteristic also of tremo-
lite asbestos deposits in the State, and, in this environment, the two
varieties cannot easily be differentiated. The fibers of both are white
and very weak.
History of Development or California Asbestos Deposits
Although asbestos has been mined sporadically in California since
1887, a full-fledged asbestos industry did not emerge in the State until
1960. This dramatic emergence is demonstrated by the production
figures, table 5. Prior to" 1960, only 9,049 tons, valued at $331,454
had been produced, whereas production during the interval 1960-1964
was 87,782 tons, valued at $6,412,764. Much of the earlier production
was of amphibole asbestos, long-fiber tremolite and anthophyllite,
mined and hand sorted from small deposits. It was sold primarily
for use as filter fiber. Current production is entirely chrysotile.
Table 5. — Ashestos produotiwi in California, 1887-19S4
Year
Short
tons
Value
Year
Short
tons
Value
Year
Short
tons
Value
1887
30
$1,800
1913
47
$1, 175
1941
16
$2, 867
1888
30
1,800
1914
51
1,530
1942
4
836
1889
30
1,800
1915
143
2,860
1943
1
723
1890 ..-
71
4,260
1916
145
2,380
1944
15, 000
1891
66
3,960
1917
136
10, 225
1945
1 37
3,605
1892
30
1,830
1918
229
9,903
1946
1893
50
2,500
1919
]■ 131
6,240
1947
1
1894
50
2,250
1920 ._
1950
} 165
12, 100
1895
25
1,000
1921
140
19, 275
1951
1
1898
10
200
1922
50
1,800
1953
} 224
16, 779
1899-
30
750
1923
20
200
1954
1900
50
1,250
1924
70
4,750
1955
1,205
21, 401
1901
1904
110
10
4,400
162
1925
1926
\ 25
1,650
1956 _.
1957
} 858
28,832
1905
1906
112
70
2,625
3,500
1927
1928
} ^^
1,160
1958
1959
} 2, 695
84, 050
1907.
1908
70
70
3,500
6,100
1929
1930
} 219
6,175
1960
1961.
J 7,280
125, 115
1909
65
6,500
1932
1
1962
5,870
321, 719
1910
200
20,000
1933
\ 309
3,274
1963
19, 591
1, 546, 890
1911
125
500
1934
1
1964
55,041
4,419,040
1912
90
2,700
Note.— Where necessary in order to conceal output of individual producers, production figures are com-
bined to cover a 2- or 3-year period. During years omitted there was no recorded production.
During and immediately after World War I, when asbestos prices
were high, attempts were made to develop chrysotile deposits in Cali-
fornia, particularly those near Copperopolis, Calaveras County, and
Washington, Nevada County. These operations failed, largely because
there was only a very limited market for asbestos on the Pacific Coast
at that time. Transportation rates made fiber from this area non-
competitive on the eastern market with that from Quebec.
The recent surge of develoiDment of California deposits was stimu-
lated by the post-World War II population and industrial boom on
the West Coast. Several new plants that manufacture asbestos prod-
ucts were constructed in California, and older ones were enlarged.
The principal asbestos products manufactured here utilize the shorter
grades of chrysotile that can be produced in abundance in California.
67-164 0—66— pt. I 7
90
MINERAL AND WATER RESOURCES OF CALIFORNIA
This growing demand resulted in extensive exploration of deposits in
Calaveras, Fresno, and San Benito Counties in 1959 and 1960, and
by 1964 four asbestos mills had been constructed to process ores from
these deposits.
Occurrences In California
Serpentine, the principal host rock for asbestos deposits, is abundant
in California, and asbestos has been found at numerous localities in
the State (fig. 7). Most of the deposits that have been worked have
been described by AViebelt and Smith (1959), but only four areas
contain deposits of chrysotile asbestos that are presently being mined.
Gopperojyolis area
The first chrysotile asbestos deposit worked in California is located
7 miles southeast of Copperopolis, Calaveras County (Kice, 1963).
This deposit is similar to those in Quebec in that the chrysotile occurs
as stockworks of cross-fiber veins in massive serpent inized peridotite.
EX PLANAT I ON
o
Amph i bole asbest os
^ Deposit worked
in 1965
Chrysotile asbestos
1. Copperopolis
Napa
Co a linga
SALTON \ -<V33-
f^s«.i"«" _N, — '
^- — ■■'■
117*
116*
FiouEE 7. Principal asbestos deposits in California.
MINERAL AND WATER RESOURCES OF CALIFORNIA 91
Width of the veins is highly variable, from less than one-thirty-
second of an inch to about an inch, but only a small percentage of
them will yield fibers more than one-fourth inch long. The ore body
apparently occupies the crest of an anticline in a large sill of serpentine.
Although several unsuccessful attempts were made to develop this
deposit in the early 1900's, not until 1959 was it thoroughly explored
by trenching and core drilling. This work indicated an elliptical-
shaped ore body, some 1,800 feet long and 375 feet in average width.
Sufficient tonnage was proved — more than 20,000,000 tons of ore con-
taining about 61^2 percent asbestos — to indicate a commercial deposit
(Merritt, 1962, p. 58). In 1962, a mill was constructed at the deposit
capable of processing 2,500 tons of ore per day and of recovering any
grade of milled fiber. The mine is now operated by Pacific Asbestos
Corp.
Napa area
A deposit of cross-fiber chrysotile asbestos in sheared serpentine,
about 18 miles northeast of Napa, was the site of a small asbestos
operation during World War II and during the middle 1950's. The
veins are narrow, ordinarily yielding fibers less than one-sixteenth of
an inch long, so that only the shorter fiber grades can be recovered
from the rock.
A 40-ton mill installed on the property in the early 1940's was inad-
equate for modem operations, so it was replaced in 1959 by a new mill
having a capacity to process about 125 tons of ore per day. It is
operated by Asbestos Bonding Co.
Goalinga area
A large serpentine mass in the southern Coast Ranges, some 20
miles northwest of Coalinga, Fresno County, constitutes one of the
largest asbestos deposits in the world. The bulk of this mass, alto-
gether some 14 miles long and 4 miles wide, has been highly sheared
and much of the serpentine recrystallized to flaky, matted chrysotile
along the closely spaced shear planes (Rice, 1963). Cross-fiber veins
are rare in this deposit, and the recoverable fiber is all short, but the
chrysotile content is very high, exceeding 50 percent in places. Fiber
produced from this deposit has attributes that promise an interesting
future for the district. Among these, Coalinga fiber is superior to
Canadian short fiber in whiteness and in its ability to absorb hydro-
carbons (Munro and Reim, 1962) .
The commercial asbestos potential of this enormous deposit, which
probably contains more than 100 million tons of ore, was not recog-
nized by the industry until 1959, when Union Carbide Nuclear Co.
l)egan filing mineral claims in the area, then largely open Federal
land. Other companies soon were attracted to the area, and by 1965,
three mills having an aggregate productive capacity of about 50,000
tons of fiber per year were in operation. Companies active there in
1965 were Coalinga Asbestos Co., Atlas Corp., and Union Carbide
Nuclear Co.
Recent discoveries and commercial development of California as-
bestos deposits indicate that the potential for new discoveries in the
92 MINERAL AND WATER RESOURCES OF CALIFORNIA
State is high. The total outcrop area of serpentine in the Coast
Ranges, Sierra Nevada, and Klamath Mountains is on the order of
2,000 square miles, and significant portions of this have not been
prospected for asbestos. It seems probable that more discoveries will
be made of Coalinga-type deposits in the southern Coast Ranges.
Also, many interesting chrysotile prospects in the serpentine masses
in Shasta, Trinity, and Siskiyou Counties (Wiebelt and Smith, 1959)
suggest that this relatively remote area is a promising one.
Selected References
Badollet, M. S., 1951, Asbestos, a mineral of unparalleled properties : Canadian
Inst. Min. and Met., Tran. v. 54, pp. 151-160.
Bowles, Oliver, 1955, The asbestos industry : U.S. Bur. Mines Bull. 552.
Merritt, P. C, 1962, California asbestos goes to market : Min. Eng., v. 14, no. 9,
pp. 57-60.
Messell, M. J., 1947, Examination and valuation of chrysotile asbestos deposits
occurring in massive serpentine : Am. Inst. Mining Metall. Engineers Trans.,
V. 173, pp. 79-84.
Munro, R. C, and Reim, K. M., 1962, Coalinga — newcomer to the asbestos in-
dustry : Min. Eng., v. 14, no. 9, pp. 60-62.
Rice, S. J., 1957, Asbestos, in Mineral commodities of California : California
Div. Mines Bull. 176, pp. 49-58.
, 1963, California asbestos industry : California Div. Mines and Geology,
Min. Inf. Service, v. 16, no. 9, pp. 1-7.
Sinclair, W. E., 1955, Asbestos, its origin, production, and utilization : Min.
Pub.. Ltd., Salisbury House, London, 512 p.
Wiebelt, F. J., and Smith, M. C, 1959, A reconnaissance of asbestos deposits
in the serpentine belt of northern California : U.S. Bur. Mines Inf. Circ. 7860,
52 p.
ASPHALT AND BITUMINOUS ROCK
(By M. B. Smith, U.S. Geological Survey, Los Angeles, Calif.)
The primary use of native asphalt and bituminous rock in Califor-
nia in the past has been for road-paving material. However, crude
oil has been recovered from these rocks at several localities. These
latter operations were not commercially successful, but it seems likely
that the future use of bituminous rock will be for its oil content.
Asphalt (brea) in California occurs at the surface where it is usu-
ally mixed with soil, and in vein-like fracture fillmgs in rocks. Some
veins are nearly pure asphalt. Bituminous roclis, mainly sandstones
or finer grained rocks impregnated with viscous asphaltic material,
crop out at the surface in many places, and in some places they extend
to depths of seA'eral hundred feet where they contain less viscous fluid
and will yield oil to wells.
Nearly all the deposits in the State are in sedimentary rocks of Mio-
cene to Recent age in the California Coast Ranges, Transverse Ranges,
and Peninsular Ranges provinces (fig. 8). Most of the deposits are
at the surface near the margins of the sedimentary basins. They also
occur in the basins where some rocks are near the surface as a result of
folding or faulting, or where oil has migrated along faults.
The present production of bituminous sandstone in the United
•States is very small, only 1,800 tons valued at $15,000 in 1963.
Past production in California has been about 1.5 million tons of bi-
tuminous sandstone with a value of $4.75 million, 219,000 tons of
asphalt with a value of $2 million, and 24,500 barrels of crude oil
with a value of $100,000.
MINERAL AND WATER RESOURCES OF CALIFORNIA
93
EXPLANAT I ON
Pr i nc i pa I occurrences
1 . Edna
2 . Casma I i a
3 . S is qu oc
4 . Grac i osa Ridge
5 . Santa Cr uz
6 . McKi 1 1 r ick
7 . Point Arena
8. La Br ea Creek
Minor occurrences
9 . Ca r p i n te r ia
10. Rancho La Brea
Figure 8. Asphalt and bituminous rock in California.
The production of native asphalt ceased long ago. The production
of bituminous sandstone reached a peak in 1910, but then decreased
rapidly as petroleum asphalt from refineries captured the market for
road paving material. It was discontinued in 1949, and the only
operation since that time has been the quarrying of a bituminous
rock which is then burned to obtain lightweight concrete aggregate
and pozzolan. Crude oil has not been recovered from such deposits
since 1959.
The resources of oil recoverable by known methods from bituminous
rocks in California are believed to be large. Estimated reserves are
about 300 million barrels that could be recovered from only those
deposits that have been quite well examined and worked in places.
94 MINERAL AND WATER RESOURCES OF CALIFORNIA
However, this oil can not be recovered at a cost now competitive with
crude oils from wells. As the recovery of this oil by quarrying or
mining would require moving about 400 million tons of rock, it seems
that some method of recovering the oil from the rocks in the ground
offers the best prospect.
Also it has been estimated (Duncan, D.C., written communication)
that 1 billion barrels of oil-equivalent could be -recovered from the
higher grade bituminous shale of late Miocene and Pliocene age in
the State, and that as much as 70 billion barrels of oil-equivalent
is present in widespread Miocene shales (Rubel, 1955).
Selected References
Adams, E. W., and Beatty, W. B., 1962, Bituminous rocks in California : Cali-
fornia Div. Mines and Geology. Mineral Information Service, v. 13, no. 4,
p. 1-9.
Ball Associates, Ltd., 1965, Surface and shallow oil-impregnated rocks and shal-
low oil fields in the United States : Oklahoma City, Okla., Interstate Oil Com-
pact Commission, 375 p.
Eldridge, G. H.. 1901. The asphalt and bituminous rock deposits of the United
States: U.S. Geol. Survey 22d Ann. Kept., p. 209-452.
Gore, F. D., 1924, Oil shale in Santa Barbara County, California : Am. Assoc.
Petroleum Geologists Bull., v. 8, no. 4, p. 450-472.
Holmes, C. X.. Page, B. M., and Duncan, D. C, 1951, Bituminous sandstone de-
posits of Point Arena. INIendocino County, California : U.S. Geol. Survey Oil
and Gas Inv. Map OM 125.
Jennings. C. W., 1957, Asphalt and bituminous rock, in Mineral commodities of
California : California Div. Mines Bull. 176, p. 59-70.
Page, B. M.. Williams, M. D.. Henrickson, E. L., and others, 1944, Geol(^y of the
bituminous sandstone deposits near Edna, San Luis Obispo, California: U.S.
Geol. Survey Oil and Gas Inv. Prelim. Map 16.
Page. B. M.. Henrickson, E. L., Williams. M.D., and Moran, T. G., 194.5, Asphalt
and bituminous sandstone deposits of part of the McKittrick district, Kern
County, California : U.S. Geol. Suney Oil and Gas Inv. Prelim. Map 35.
Page. B. M.. Williams, M. D., Henrickson, E. L.. and others. 1945. Bituminous
sandstone deposits near Santa Cruz, Santa Cruz County, California : U.S.
Geol. Survey Oil and Gas Inv. Prelim. Map 27.
Rubel, A. C, 1955. Shale oil as a future energy resource : Mines Mag., Oct. 1955.
p. 72-76.
U.S. Department of the Intei-ior, Energy policy staff. 1963, Supplies, costs, and
uses of the fossil fuels : U.S. Dept. Interior, 34 p., tables.
Williams, M. D., and Holmes, C. N., 1945, Geology of oil-impregnatetl diatomace-
ous rocks near Casmalia. Santa Barbara County. California : U.S. Geol. Survey
Oil and Gas Inv. Prelim. Map 34.
BARITE
CBy F. H. Weber, Jr., California Division of Mines and Geology, Los Angles,
Calif.)
Barite, naturally occurring barium sulfate, is the heaviest of the
)ionmetallic industrial minerals ; its specific graA-ity is 4.6. It is used
principally as a weighting agent in oil and gas well drilling fluids, and
to manufacture barium cliemicals; lesser amounts are used in paints,
rubber, and glass, as high-density aggregate in concrete for nuclear
shielding, and for other purposes. The United States is the leading
world producer, importer, and consumer of crude barite, with a con-
sumption in 1963 of 1,400,000 tons, valued at about $14,000,000. Of
this amount, 824,000 tons, valued at $9,447,000 was mined domestically.
MINERAL AND WATER RESOURCES OF CALIFORNIA 95
principall;^ in Missouri, Arkansas, Georgia, and Nevada, with smaller
quantities in California and several other states.
The total recorded output of barite mined in California, from 1910
to 1963, is 735,000 tons, with a value of $5,440,000. The annual con-
sumption of the crude mineral from 1959 to 1963 by California indus-
tiy fluctuated between 100,000 and 130,000 tons, but only about 5,000 to
15,000 tons were mined annually in the State. Most of the crude
Ijarite rock consumed in California is mined in Nevada, where de-
posits are numerous and commonly large and relatively high iii grade;
they yield barite rock of at least 4.2 in specific gravity, the minimum
weight suitable when crushed and gromid, for use in drillmg fluids.
Thus the resultant low cost of the crude mineral compensates for the
relatively high transportation cost to California processing facilities.
Crude barite for use ni drilling fluids is processed in California prin-
cipally/- by Baroid Division of National Lead Co., Macco Corp., Calada
Materials Co., Industrial Minerals and Chemical Co., and Yuba Min-
erals and Milling, Inc. ; barium chemicals are manufactured by FMC
Corp. The value per short ton of crude barite delivered to these
facilities, ranges from about $13 or $14 to about $22 or $23 per ton,
the value generally being higher in southern California. Fluctua-
tions in the amount of barite consumed in the State generally reflect
the activity in drilliiig, with less activity in mid-1965 reflected in lesser
tonnages of barite being consumed.
Though California furnishes only a small proportion of the crude
barite rock that it consumes, the State contains more than 150 known
barite localities, including 7 deposits that have yielded more than
15,000 tons, and about 15 deposits which have yielded from 100 to
10,000 tons as shown on fig. 9 and on table 6. Deposits mined since
1960 that have yielded at least several hundred tons are the Ninemile
Canyon (1961-1963) and Bald Mountain (1963-1965) in the Sierra
Nevada; the Glidden Co. (1962-1964) and Alwood (1962) in the
Klamath Mountains; the Gunter Canyon (1962-1965) in the White
Mountains; and the Leviatlian (1961) and Silver Bow (1961) in the
Calico Mountains.
Slightly more than 90 percent of the total barite mined in California
has come from 5 deposits that are part of a crude belt which extends
at least from the southern to the northern Sierra Nevada; and may
extend, interrupted by the Cascade Mountains, into the Klamath
Mountains. The deposits occur in metamorphic rocks of the Cala-
veras Formation and similar units. Of these 5 deposits, 2 lie in the
southern part (El Portal, Ninemile Canyon) and 3 in the northern
part (Almanor, Democrat, Spanish). The deposits of the southern
part, consist of long, steeply dipping vein-like bodies of quartz-barite
rock which averages about 3,9 to 4.1 in specific gravity. These bodies
occur within north- to northwest-trending linear zones which are at
least 3 miles in length, but commonly are offset by minor faults; in-
dividual fault segments of the barite bodies are at least 3,000 feet in
length, and range in thickness from 1 to 40 feet and perhaps average
3 to 8 feet. Nearly all barite rock mined has been upgraded by jigging
(Ninemile Canyon, Bald INIountain) or by a combination of jigging
and sink-float (El Portal, mined from 1910 to 1948, and the source of
almost 60 percent of the total barite mined in California) . The most
96
MINERAL AND WATER RESOURCES OF CALIFORNIA
124- 123. J22. J21
r\ ) I ^\
^ ( s I s K r V o\^
120°
L42.
m 1
^^"^ O MO DOC I
41'
Eureka
i)^-h,AMA»PT(
s
a
o
5
TRINITY
*SSE^
^ [_ f->\TEHAMA '
^0% V A. -
Plumas
r-v.--
'NEVADAr-.
Co- >■. f ^''5k'' ""V >35s1erra
^% tl % ;.■: ,1
— • \ .' * VrtinV. I \/fi nf»R*T»0 ^V
"y \ ^' I yOLo'^--l.._y EL DORA'
?"NOMASnaA^' ^
^•,
TUOLUMNE 1\mONO\ -\- :
Fmnc
/.-_ „ ,
VantXO >\MERe«Di.^ -X -a'
37- — \cK?Vi,-_; n1 /\ V ^
,,--KSA^<S ^
vpENITOl
MONTEREy^'')
3e-f V
122'
EXPLANAT I ON
Prospect: or known output less
than 100 tons ol crude barite
Output 100 to 10,000 tons
Output more than 10,000 tons
Pr ocess i ng facilities
a . Bar 0 Id , Ma reed
b . Ca lada , Harbor City
c. FMC, Modesto
d. Industrial Minerals, Florin
e . Mace 0, Rosamond
I . Yuba , Suiter City
118'
SAN BE#NARDINO 32 \
* 1 8 \
Sd"
121'
.^^.V^_A^5^,gANGEsV
<>..]:rr::- ' TF y-,V
33'
DESERT ^i
^'
1 n F •
+ \^ -j- ) SAN DIE""
119° 118°
VMPEKlAr
,SALTON \ -=,33°
TROUGHjS:^
m° "^"
Figured. Barite in California ( numbers refer to table 6 ) .
recently developed deposit is the Bald Moimtain; this deposit and the
Devils Gulch together probably contain at least several hundreds of
thousands of tons of barite rock to a depth of 50 feet or less. Deposits
in the northern part of the belt consist of dark-gray barite, from 3
to 10 feet thick, which is interlayered with phyllite and related rocks;
the three productive deposits now are mostly worked out at the surface.
Projections of linear zones within this belt, utilizing known geology,
would make excellent targets for future prospecting.
In recent years, the Glidden Co. deposit, on Girard Ridge in the
Klamath Mountains, has been the principal State source of barite rock
of greater than 4.2 specific gravity. This deposit consists chiefly of
dark-gray barite from 3 to 10 feet thick which is interlayered with
MINERAL AND WATER RESOURCES OF CALIFORNIA 97
Tabic 6. — Barite deposits of California
[Numbera refer to localities shown in fig. 9]
I. Afterthought and others (including Hirz Mount. Greenwood, Exposed Treas-
ure, Bidwell, Ranch) (a).
2. Almanor (includes Cameron, Syntheticlron Color mines) (e).
3. Alwood (a).
4. Austin (e).
5. Bald Mountain (two properties : Baro, Palonia) (b).
6. Buckhorn (b).
7. Calico Mountains and vicinity deposits (include Barium Queen, Big Medicine,
Burcham-Waterloo, La Mountain, Lead Mountain, Leviathan, Mount
General, Penny, Silver Bow, Silverado, Waterman) (b, d) .
8. Callahan Ranch lead-barite (e).
9. Camp Nelson (a).
10. Chickencoop Canyon barite-witherite-sanbornite (a).
II. Clavey River (e).
12. Death Valley region (Bradbury Well, Miller Spring, Greenwater, Warm
Spring Canyon (a).
13. Democrat (c).
14. Devils GiUch (EgenhoflE) (b, c).
15. El Portal (b, c).
16. Fremont Peak (Gabilan Peak) (a).
17. Glidden Company (Loftus) (C).
18. Hansen and others (including Ludlow Belle) (b).
19. Indian Valley (Dawn) silver-barite (d).
20. Kingston (e).
21. Labrea Canyon (c).
22. Liscom Hill (a).
23. Mountain Pass (Molybdenum Corp. of America) rare-earth minerals (d).
24. Ninemile Canyon (Paso Barvta ; includes Barite King mine) (b, c) .
25. Noble (e).
26. Ord Mountain copper-gold (d).
27. Palo Verde (includes Palo Verde, White Swan properties) managanese-
barite (a).
28. Pine Hill gold (d).
29. Pipeline Canyon (a).
30. Red Hill mercury (a).
31. Ritter Ranch (a).
32. Sacramento Mountains barite-fluorite, etc., deposits (a).
33. San Dimas (a).
34. Sands (a).
35. Spanish (c).
36. Topaz (a).
37. White Mountains deposits (including Gunter Canyon, White Mountains,
Bitch, Starr, Last Chance, and Smith) (c).
EXPLANATION OF LETTERS IN PARENTHESES, ACCOMPANYING NAMES OF DEPOSITS
(a) Relatively small deposits, large tonnages of barite rock not apparent at
surface. Potential seems limited.
(b) Large or possible large tonnages of lower grade rock of less than 4.2 specific
gravity, as indicated in text.
(c) Small to large tonnages of rock may exist beneath present surface workings.
Largely mined out at surface.
\ d ) Barite might be recovered as a by-product.
(e) Potential undetermined.
gently dipping, mildly metamorphosed siltstone and shale of Devonian
age. The barite occurs stratigraphically at an interval of about 15
to perhaps several hundred feet beneath several large, adjacent bodies
of limestone. This limestone occurs in a north-northeast-trending
belt 11 miles long which should be prospected for additional barite.
The Calico Mountains and vicinity, on the Mojave Desert, is the
site of a famous old silver district which was active mainly from 1882
98 MINERAL AND WATER RESOURCES OF CALIFORNIA
to 1896. Barite occurs principally as an important gangue mineral in
noi+hwest-trending silver-bearing veins which consist mostly of jas-
per. Barite seems to be most abundant in the northwest part of the
Calico district itself, and at the AVaterman and Lead Mountain mines.
The most important barite recovery oi>eration has been at the former
Le\'iathan silver mine, where the mineral was recovered from 1957 to
1961 by air separation from nx^k of about 3.5 in specific gravity.
Barite once was recovered briefly from the tailings of the Waterman
mine ; and small tonnages of barite of 4.0 to •4.2 grade have been shipped
from the Silver Bow and other properties. Recently active prospects
include the Penny and Big Medicine, which may contain large ton-
nages of low-gi'ade rock. Deposits similar to the Calico Mountain
deposits are the Hansen and others, which lie to the east.
At Mountain Pass, on the Mojave Desert,, the Molybdenum Corp. of
America recovers rare-earth minerals from large carbonate bodies
which consist also of 20 to 25 percent barite ; barite might be recovered
as a by-product at the recently ex])anded operation. The Gunter Can-
yon and other deposits in the White Mountains consist of generally
thin veins of connnonly high grade barite. Also of possible significance
is the Labrea Canyon deposit, mined out at the surface, but possibly
containing additional white barite bodies below the surface. A re-
cently located deposit is the Buckhorn, in the eastern Sierra Nevada,
which consists principally of two adjacent, north-northwest -trending,
irregular zones which are about 150 feet long and 35 to 75 feet wide;
the zones consist of white, granular barite which is very thinly inter-
layered with silicified mudstone ("chert"). Small quantities of white
barite occur ii\ the Afterthought and several similar deposits in the
Klamath Mountains, and in the Palo Verde deposit on the Mojave
Desert. Additional deposits that have been prospected in recent years
are the Sands, Kingston, and Topaz.
The greatest potential resources of barite in California consist of the
larger, lower grade deposits which mostly today cannot compete with
rock shipped into California from Nev^ada. A factor that might lead
to greater exploitation of these deposits is the use, in recent years, of
some lower grade barite for drilling; one company, for example,
markets a product of 4.0 specific gravity. In addition, greater amounts
might be produced competitively by beneficiation, or as a by-product,
especially if tlie higher grade Nevada deposits become depleted.
Selected References
Brobst, D. A.. 19.58, Barite resources of the United States: U.S. Geol. Survey
Bull. 1072-B. p. 67-130.
Brobst, D. A., and Ward, F. N., 1965, A turbidimetric test for barium and its
geolog-ic application in Arkansas : Econ. Geology, v. 60, no. 5. p. 1020-1040.
Drake. H. J.. 1964, Barite, from Minerals Yearbook 1964: U.S. Bur. Mines, pre-
print, 12 p.
Horton, R. C, 1963, An inventory of barite occurrences in Nevada : Nevada Bur.
Mines Rept. 4. IS p.
Kundert, C. J., 19.57, Barite, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 71-74.
Lewis, R. W., 1965, Barium, a chapter from Mineral facts and problems 1965 ed. :
U.S. Bur. Mines Bull. 030, preprint, 9 p.
Tyler, P. M., 1945, Barium minerals, in Taggert, A. F., Handbook of mineral
dressing — ores and industrial minerals : New York, John Wiley and Sons,
Inc., p. 3-06 to 3-09.
Weber, F. H., Jr., 1963, Barite in California : California Div. Mines and Geology
Min. Inf. Serv., v. 16, no. 10, p. 1-10.
MINERAL AND WATER RESOURCES OF CALIFORNIA 99
BERYLLIUM
(By E. B. Gross, California Division of Mines and Geology, San Francisco, Calif.)
Beryllium is one of the less common lightweight metals which has
become a more significant connnodity as new uses for it have devel-
oped. Since 1945, beryllium and beryllium oxide have been fabricated
into rods used in nuclear reactors to moderate the speed of fission
neutrons and to control tlie reflection of neutrons to the reactor core.
It has been used also in neutron gen^^rators as a neutron source.
Metallurgical uses of beryllium consume most of the metal pro-
duced. Small amounts of beiyllium added to steel increase its tensile
strength. However, its ability to add strength and hardness to soft
and ductile metals such as copper, aluminum, and magnesium in-
creases its usefulness in alloys of the lighter metals. More than half
of the total beryllium is used in a beryllium-copper alloy which is
hard, resistant to fatigue, and non-magnetic. Uses for this alloy in-
clude springs, special tools, and other non-magnetic devices. A light-
weight beryllium-aluminum alloy has found limited applications in
air-frames and structures of aircraft and missiles and for guidance
mechanisms. Beryllium oxide has been used in refractory materials,
where its high electrical resistivity and melting point of 4,658°F is
advantageous.
Increasing uses for beryllium have necessitated more intense ex-
ploration for source materials. Research equipment such as beryl-
lometers (neutron activation detectors) and a fluorescent method for
detecting small amounts of beryllimn in rocks have evolved. In 1964,
beryllium ores were processed only in Pennsylvania and Ohio.
The primary occurrence of beryllium is within pegmatite dikes asso-
ciated with granitic and syenitic intrusive bodies; deposits have been
found in quartz-rich veins associated with fluorite and in veins within
quartz monzonite. Lately, the most promising source of ore has been
the disseminations of beryllium-bearing minerals in granites and
rhyolitic tuffs. Beryllium-rich tactites contain helvite or beryllium
dispersed w^ithin the contact minerals of the replacement deposit. Al-
luvial occurrences, derived from primary intrusive igneous rocks, have
been the source of only limited production. Beryllium has been found
in about 43 minerals, of which only three contam sufficient beiyllium
to be of interest as source materials. Beryl (BeaAlaSieOis) is the
principal ore mineral and is obtained chiefly from zoned granitic peg-
matite bodies, most commonly within the inner zones. Because of this
sparse distribution, conventional mining and concentration processes
are not followed, and most of the ore has to be concentrated by hand-
cobbing. Recently deposits of lower grade containing the beryllium
mmerals phenacite (Be2Si04) and bertrandite (Be4Si207(OH)2*) have
been found disseminated in rhyolitic tuffs.
The element, beryllium, was discovered by the French chemist Louis
Vaugelin, in 1797. An appreciable amount of beryllium was produced
by F, Wohler of Germany in 1828. In 1916, the first ingot of beryl-
lium metal was obtained in the United States, but interest in uses of
beryllium did not develop until 1926, when it was alloyed with copper.
The beryllium industry grew from this and similar metallurgical uses.
100
MINERAL AND WATER RESOURCES OF CALIFORNIA
Production of beryllium ore in the United States has declined since
1957 (see table 7) . In 1963, only one ton of ore was produced follow-
ing the removal of government price support. World production m
1957 was 11,300 short tons of 11 percent BeO, compared to about 6,500
tons in 1964. Brazil yielded most of the foreign production. In the
United States, 14 states produced beryllium ore, but no deposits in
California have been exploited.
Table 7. — World production and U.S. consumption of beryllium
[In short tons]
World
production
U.S.
production
U.S.
consumption
1956
12,900
11.300
7,450
11,200
12,300
12,900
10,900
7,400
6,500
445
S21
463
326
244
317
218
1
>17
4,341
1957 —
4,309
1958
6,002
1959
8,173
I960
9,692
1961
9,392
1962 —
7,758
1963 .- —
7,934
1964
15.800
1 Estimated.
Beryl has been found in many pegmatites in California, primarily
in the Peninsular Ranges of San Diego and Riverside Counties (see fig.
10). Two beryllium discoveries include one near Lone Pine, Inyo
County, in the Great Basin province and the other in pegmatites near
Jacumba, San Diego County (Weber, 1962). No commercial pro-
duction has come from either of these deposits. A list of beryllium-
bearing deposits, chiefly containing beryl, are given by county in table
8. Other rare beryllium-bearing minerals are mentioned in the table.
Table 8. — Beryllium deposits in California
Index
No. on
fig. 10
Pegmatite deposits
County
References
Near Academy.
Fresno -
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
East of Lone Pine
Mount Lowe area
Thompson Gem mine, Mount Thompson
Fano mine, Coahuila Mountains
Near Hemet- -
Jensen quarry, near Riverside
Mears, base of Box Spring Mountain
Southern Pacific silica quarry, near Nuevo
Aguange Mountain, near Oak Grove
Katrina deposit, near Pala (helvite, phenacite,
bertrandite) .
Himalaya and Esmeralda mines, Mesa Grande —
Mac mine, near Rincon (helvite)
Mines near Ramona (hambergite)
Crystal mines, near Jacumba
Near Jamestown .-. —
Inyo
Los Angeles.
Lassen
Riverside.-.
do
do
do
do
San DiegO-
do
...do.
...do-
-.do-
CONTACT METAMORPHIC DEPOSIT
West of Lone Pine (mineral not identified).
.do
Toulumne.
Inyo.
CaUfomia Division of
Mines Bulletin 173.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
U.S.G.S.MapMR-35.
MINERAL AND WATER RESOURCES OF CALIFORNIA
101
EXPLANATION
Beryl |iu m prospec t
■-■9 '-V -T- -
H I5,i
117'
Figure 10. Beryllium in California (numbers refer to table 8).
Future appraisal of beryllium deposits in California will depend on
improved exploration techniques, applying new research instruments
for detecting large, low-grade disseminated deposits. Large tonnages
of low-grade beryllium ore perhaps may be present in some of the
Mojave Desert and Great Basin provinces of California, analogous
to the deposits already delineated in Utah, Colorado, and Nevada.
However, exploitation of these low-grade deposits will be delayed
until adequate processing procedures are resolved. Only minor quanti-
ties of beryl have been obtained from contact metamorphicf rocks and
alluvial deposits.
102 MINERAL AND WATER RESOURCES OF CALIFORNIA
Selected Refebences
Eilertsen, D. E., 1962, Beryllium : California Div. Mines and Geology, Min. Inf.
Service, v. 15, no. 2, p. 12-18.
Griffitts, W. R., Larrabee, D. M., and Norton, J. J., 1962, Beryllium in the United
States : U.S. Geol. Survey Mineral Inv. Resources Map MR-35.
Murdoch., Joseph, and Webb, R. W., 1956, Minerals of California : California Div.
Mines Bull. 173, p. 74-76, 249.
U.S. Bureau of Mines, 1965, Commodity data siunmaries, p. 14-15.
Warner, L. A., Holser, W. J., Wilmarth, V. R., and Cameron, E. H., 1959, Occur-
rence of nonpegmatite beryllium in the United States : U.S. G^ol. Survey Prof.
Paper 318, p. 198.
Weber, F. H., Jr., 1962, A beryl discovery in southeastern San Diego County,
California : California Div. Mines and Geology, Min. Inf. Service, v. 15, no.
2, p. 8-11.
Wright, L. A., 1957, Beryllium, in Mineral commodities of California : California
Div. Mines and Geology Bull. 176, p. 75-78.
BISMUTH
(By Q. A. Aune, California Division of Mines and Geol(^y, Redding, Calif.)
Bismuth is a brittle, silver- white metal with a reddish hue, and has
a low melting point of 271.3°C. Its principal uses depend on its
ability to impart, desirable qualities of f usability, castability, and ma-
chinability to a wide variety of industrial alloys; and on its value as
an ingredient in pharmaceutical compounds, salts, and mixtures used
for indigestion remedies, antacids, bum and wound dressings, anti-
syphilitics, dusting powder, and cosmetics.
Bismuth is obtained mainly as a by-product in the metallurgical
treatment of silver, lead, zinc, copper, gold, tungsten, tin, and molyb-
denum ores. Native bismuth, bismuthenite, and a number of other
bismuth-bearing minerals are commonly found in stringers and pockets
in hydrothermal veins with the above ores. Bismuth minerals also
occur in contact metamorphic deposits and in pegmatites.
Twenty tons of bismuth ore were mined at the Lost Hoi'se mine.
Riverside Comity, in 1909 ; concentrates containing up to 14 percent
bismuth were obtamed from the Garnet Dike tungsten mine, Fresno
Comity, but no attempt was made to recover bismuth from the con-
centrates.
Bismuth occurrences are relatively widespread, as shown in figure
11. The paucity of recorded California production is not an indica-
tion of the lack of production, but signifies that the source of the bis-
muth was not reported. The by-proMduct relationship of bismuth to
other metals coupled with the small domestic supply places a major
reliance on foreign sources and marketing of bismuth material.
Native bismuth and several oxidized bismuth minerals have been
reported with, arsenopyrite and gold in quartz veins at the Big Blue
group of mines in Kern Comity. The Darwin and other mines of
the Darwin district, Inyo County, contain bismuth in association with
lead-silver-zinc-tungsten ores. Mineralization is in replacement and
vein deposits in limestone and calc-silicate rocks. Bismuth is asso-
ciated with gold-copper vein deposits between Tertiary monzonite
and rhyolite at the Bagdad-Giase mine, San Bernardino County ; it
also occurs in the form of a bismuth sulfide associated with copper
MINERAL AND WATER RESOURCES OF CALIFORNIA
103
EXPLANAT I ON
o
120*
-.L4
- — „^ Relatively important deposit
S ! Single deposits or clusters of
deposits that have produced bis-
muth: or depos it s that contain
-. at least 0.027o bismuth in ores or
^<: \.\^'''concent rates : or deposits reported
"f^- I to contain fairly abundant bismuth
mine r a Is .
Re ported occurrences
Single deposit or clusters of
depos it s that contain bismuth
minerals : or depos it s from which
si^lected samples of ores or con-
c^Wtrates contain at least 0.02%
b i smuth .
After Coope r (1 962 )
116-
Figure 11. Bisnuith in California.
minerals in a quartz vein that cuts a foliated micaceous quartzite at
the Lost Horse mine in the Pinon Mountain district, Riverside County.
At the Garnet Dike tunfrsten mine, a contact metamorphic deposit
in Fresno County, bismuthinite occurs with scheelite in a tactite zone
having the form of a vertical chimney with a maximum diameter of
about 60 feet. Bismuth occurs in association with tungsten-molyb-
denum-copper ores in tactite near a quartz monzonite contact at the
Pine Creek mine, Inyo County. Oxidized bismuth minerals occur
with garnet, epidote, clinozoisite, and other contact metamorphic
minerals in a highly metamorphosed limestone at the United Tmigsten
copper mine in San Bernardino County. Native bismuth, bismuth-
104 MINERAL AND WATER RESOURCES OF CALIFORNIA
inite and bismutite occur with tourmaline, lepidolite, and other peg-
matite minerals in the gem mines at Pala, Rincon, and Jacumba, San
Diego County.
There are numerous other bismuth occurrences in California that
are unappraised or are regarded as having no potential importance
as sources of the metal. Since between 80 and 90 percent of the annual
total TTnited States consumption (roughly 1,000 tons) is in the
northern and eastern United States, California ore has little market-
ing advantage over foreign ores.
Selected REFiatENCES
Anonymous, 196-5, The changing pace and pattern in the business of mining:
New York:, Eng. and Mining Jour., v. 166, no. 2, p. 138-139.
Chesterman, C. W., 1957, Bismuth, in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176, p. 79-81.
Cooper, J. R.. 1982, Bismuth in the United States: U.S. Geol. Survey Mineral
Inv. Resources Map MR-22.
Logan, C. A., Braun, L. T., and Vernon, J. W., 1951, Mines and mineral resources
of Fresno Countyi California : California Jour. Mines and Geology, v. 47,
no. 3, p. 485-522.
Moulds, D. B., 1964, Bismuth, in U.S. Bur. Mines 1963 Minerals Yearbook:
U.S. Bur. Mines, v. 1, p. 311-315.
Prout, J. W., Jr., 1940, Geology of the Big Blue group of mines, Kernville, Cali-
fornia : California Jour. Mines and Geology, v. 36, no. 4, p. 413.
Tucker, W. B., and Sampson, R. J., 1929, Riverside County : California Div.
Mines, Mining in California, 25th Rept. State Mineralogist, v. 25, no. 4, p. 483.
U.S. Bur. of Mines, 1965. Bismuth, in Mineral facts and problems : preprint,
U.S. Bur. Mines Bull. 630, 8 p.
BORAX AND OTHER BORON COMPOUNDS
(By W. C. Smith, U.S. Geological Survey, Menlo Park, Calif.)
About 100 years ago California became the first domestic producer
of borax, and about 40 years ago it became the largest supplier of boron
raw materials to the world market (Ver Planck, 1956 and 1957; W. C.
Smith, 1960 and 1962). California's share of world production has
been 90 i^ercent in many years, and probably will be nearly as large in
the future, although Turkey has been increasing its production and
Argentina and Chile have large deposits that are potentially more
productive than they have been in the past. California's leadership
of the world's borax industry has been based upon large-scale, eco-
iiomical operations at two major boron deposits, Searles Lake and
Kramer, each established in the late 1920's and repeatedly expanded
as consumption required. The known reserves in these two major
deposits and in potentially workable colemanite deposits are estimated
to be large enough to sustain California's production at recent rates
for the next hundred years.
In the following description of use, production, and geologic occur-
rence of borax and other boron compounds, it will be convenient to refer
by name to the principal compounds and boron minerals of California,
so tliese are listed on table 9, with chemical composition and boron
content. Borax is chemically the same, whether mineral, industrial
compound, or tlie familiar household pharmaceutical.
MINERAL AND WATER RESOURCES OF CALIFORNIA 105
Table 9. — Principal bormi compounds and minerals of California
Name
Chemical composition
Boron content (calcu-
lated weight percent)
B
B,0,
Chemical compounds:
Borax
NajBiOT-lOHjO..-
11.3
21.4
17.5
11.3
15.8
13.3
15.4
15.7
36.5
Anhydrous borax -- -
NasB407
69.1
Boric acid . . . .
H3BO3
56.4
Minerals:
Borax -
Na2B407lOHjO
36.5
Kemite
NasB407-4H20..-
51.0
Ulexite
NaCaBsOg-SHjO
42.9
Probertite
NaCaBsOicSHsO
49.6
Colemanite --
CajBeOii-SHjO
50.8
Uses of Boron Compounds
The use of boron comix>unds has increased over the years, and this
trend is expected to continue. Among the scores of industrial, agri-
cultural, and consumer uses, the largest is that of borax in glass and
glazes. About a fourth of production goes into glass, notably fiber-
glass, heat-resistant glass, and optical glass. The many uses in the
chemical and allied industries are summarized by Johnstone and
Johnstone (1961), and recent research in boron compounds is reviewed
each year in the Minerals Yearbook of the V.S. Bureau of Mines
(Miller, 1964; Stipp and Schreck, 1963, etc.).
Production
Borax mining began in 1864. In the five-year period 1959 to 1963,
inclusive, California's production of borax and other boron compounds
was equivalent to 331,941 tons of B2O3 per year, with a value near
$49,000,000 per year (Miller, 1964). Boron "is exceeded in value of
products only by oil, gas, and construction materials. Figures for
production combine all products and are in terms of equivalent tons of
B0O3. Most of the raw material is processed in elaborate plants at the
deposits, and the principal bulk commodities shipped are refined borax,
anhydrous borax, and boric acid. The California producers ship only
minor tonnages of crushed or otherwise partly treated borate minerals.
A trend toward higher values per ton should be recognized; among the
reasons for it are the increase in shipments of anliydrous forms (to
save on freight costs) and the increase in numl>er of refined boron com-
pounds prepared at the primary plants.
California supplies essentially all the boron products consumed in
the United States, although small quantities of special boron-bearing
materials are imported. About half the production is exported. Dis-
tribution abroad is mainly to the highly developed industrial areas
of the free world. For other regions, accurate statistics are not avail-
able, but we believe that only the U.S.S.R. and China are producing
and that their output is less than that of the free world (Sokoloff,
1964).
Geologic Occurrence
In California, the principal boron deposits are in the Mojave Desert
and adjacent parts of the Great Basin in the eastern and southeastern
671-164 O — 6&— pt. I 8
106
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANAT I ON
O O
Borax
Kramer
Br ine
2. Owens Lake
3 . Sear les Lake
Coleman i te
Ca I ico
Four Corners
Frazier Mtn.
Furnace Creek group
8. Lang
9. Shoshone-Gerst ley
A
Minor deposits
10. Amargosa
1 1 . Borax Lake
12. Eagle
13- Harmony
14- Koehn Lake
J5. Sa line Va I lev
Figure 12. Boron in California.
pai-ts of the State (fig. 12) . Boron is not known to occur in nature as
the element. And here, as elsewhere, the boron is in solution in water
or combined witli other elements in hydrated sodium and calcium
borate minerals, among- which the best known is borax (see table 9).
All the deposits in California are geologically young (Cenozoic) and
of continental origin. They are classed as evaporites, with the de-
posits of common salt, sodium carbonate, and sodium sulfate that orig-
inate as saline residues where surface water dries up in arid inland
basins. Evaporation is almost the whole story of origin for many of
these salines, with the important qualification that during the crucial
final stages when minerals come out of solution the dominant process —
sometimes the only process that can be identified later from the exist-
ing mineral assemblage — may be temperature change (for borax, cool-
ing) , or chemical reaction as waters mix, or replacement of susceptible
minerals. Equally important for the origin of boron deposits in arid
basins is location within one of the world's Cenozoic volcanic-tectonic
MINERAL AND WATER RESOURCES OF CALIFORNIA 107
belts, where waters contain significantly more boron than average.
Many California and western Nevada waters are boron-bearing, pre-
siunably because of some fundamental relationship to the well-lmown
belt that follows the Pacific Ocean margin. Where this volcanic-
tectonic belt passes through areas long dominated by inland basins and
arid climate, as in western South America between latitudes 15° and
30° S. as well as in California, the accimiulated salines include mujor
borate deposits.
Searles Lake brine
At Searles Lake borax is recovered from brine that also yields potash,
sodium carbonate, and several minor coproducts. Two large chemical
plants, operated by American Potash & Chemical Corp. and Stauffer
Chemical Co., treat brines pumped from groups of shallow wells that
penetrate saturated layers of crystalline saline minerals in a section
of lake beds underlying the Searles Lake play a (Teeple, 1929) . Halite
of the uppermost saline layer is exposed in the center of the playa,
where it forms a hard salt pan 10 or 12 square miles in area. The
layers containing the commercially valuable brines also underlie the
mud flats that encircle the central salt, so their total extent is about
40 square miles. In the stratigraphic section, the productive saline
layers are in two zones, separated by a "parting mud" that is 12 or 14
feet thick, and underlain by a "bottom mud." The upper saline zone
generally is 70 to 80 feet thick, the lower zone 30 to 40 feet. In these
zones, it is estimated, about 40 percent of the volume is brine. The
subsurface layers of saline minerals are more or less coarsely crystal-
lized and have a porous, vuggy structure, so they yield brines freely.
The brine stands essentially at the surface of the playa, the brine level
evidently being maintained there by subsurface flow.
Reserves at Searles Lake have been estimated as adequate for 50
years production (Dyer, 1950), and an estimate in these terms is more
appropriate than separate figures for tonnage and grade of the several
coproducts, all of which must be produced and marketed.
As the lake beds of this saline deposit lie where they accumulated,
evidence of their origin is obtainable not only from study of the
stratigraphy and mineralogy of the sediments but also from study of
the topography of the basin and the region. The slopes above the
playa are marked with many ancient shorelines, the highest at 640
feet above the salt flat at a position fixed by tlie altitude of an overflow
channel leading eastward to Panamint Valley. These show that the
basin has contained a succession of lakes. Regional surveys have
shown that the lakes received water mostly from the west, and mainly
from a long section of the eastern slope of the Sierra Nevada that
drains via the Owens River into Owens Lake (Gale, 1915). In cool
moist periods of the past, Owens Lake would overflow and the runoff
would go through China Lake into Searles Lake and, at maximum
flow, beyond. In the commercially drilled sediments of Searles Lake,
then, one major climatic swing from cool-moist to warm-dry is repre-
sented by the bottom mud and lower saline zone, another by the parting-
mud and upper saline zone (Flint and Gale, 1958; Smith, G. I., 1962;
Smith and Haines, 1964) .
The quantities of chemicals concentrated in Searles Lake required
evaporation of enormous amounts of Owens River water, which pre-
sumably had a composition alx)ut the same in the Pleistocene as it is
now (339 ppm total dissolved solids and 1 ppm boron; Clarke, 1924).
108 MINERAL AND WATER RESOURCES OF CALIFORNIA
Chemical analyses of Owens River water show that the principal
source of its boron is a g-roup of thermal springs in the headwaters
region, nearly 150 miles from Searles Lake. The Searles Lake brines
contain about .34.5 percent total dissolved solids, including 0.35 percent,
boron (commonly reported as l.() or 1.7 percent of NaoBiO:; see
analyses in table 44). The "solid" minerals of the saline layers were
also once in solution; they are halite, trona, hanksite, and several less
abundant sodium chloride, sulfate and carbonate minerals. Addi-
tional chemical precipitate is in tlie main mud layers and the thin mud
layers within the saline zones; they contain much calcium carbonate
in gaylussite, aragonite, calcite, and dolomite (Smith and Haines,
1964). Boron is distributed through the section. In addition to the
boron in brine, the deposit contains crystalline borax, the amount
ranging from a few crystals in the bottom mud and at several other
horizons to a borax lens 5 feet thick in the upper salt.
Kramer horax deposit
At Kramer, bedded borax interlayered witli shale and siltstone is
mined from a large open pit and processed in an adjacent refinery by
the U.S. Borax »)i Chemical Corp. (Barnard and Kistler, 1965). The
lake beds that contain the borax have no known outcrops — the ore was
found by drilling — and they lie at depths of 150 to 1,000 feet, beneath
younger beds recently found to be middle Miocene in age (R. H. Ted-
ford, written conmiunication, 1965). The ore contains, on average,
nearly 25 percent BoO.f. It is as much as 200 feet thick and extends
under about 500 acres. Reserves are estimated to be about 100 million
tons. Even at recent high rates of extraction, this is about 100 years'
reserve.
The lithology and mineralogy of the Kramer ore body require
classing the borax as a lake deposit, and as an evaporite only in a
qualified sense. The associated sediments lack structural features
attributable to desiccation, and the array of saline minerals that typi-
cally result from extensive evaporation is absent. The shale and
siltstone beds are thin and banded, and, like the occasional layers of
tuffaceous sandstone, they persist laterally with uniform thickness and
composition. Along beds, the initial borax content seems to vary
little, but in vertical section, the ore ranges from lean to rich, some
layers being shale containing scattered borax crystals and others
nearly solid borax enclosing scattered lumps of shale, with gradations
between. Apparently the 200-foot section of borax and accompany-
ing sediments accumulated in a quiet, continuous lake in which condi-
tions varied from time to time, but only in a narrow range. That the
precipitation of borax probably was caused by cooling seems likely,
and overflow to carrv awav other saline components seems required
(Gale, 1946; Bowser, 1964).
Among other borate minerals at Kramer, colemanite and kernite
occur in quantity. Colemanite was the first borate found in the
district (1913) and, with associated ulexite, was the first borate mined
(1924 to 1927). Colemanite occurs in a thin zone which is above the
borax ore body, and which also underlies a much larger area, about a
mile by 4 miles in extent (Gale, 1946). Kernite, which was mined
for several years after 1927 but is not processed in the present opera-
tions, extensively replaces borax in the deeper parts of the ore body
(Christ and Garrels, 1959: Schaller, 1929).
MINERAL AND WATER RESOURCES OF CALIFORNIA 109
(Jolemanite deposit h
Colemanite and ulexite are produced in the Death Valley region,
where the U.S. Borax & Chemical Corp. oj^erates one mine near
Shoshone and one in Corkscrew Canyon, and the Keni Comity Land
Co. operates one mine in Furnace Creek wash. A few hmidred tons
l^er year of the calcium-bearing borates are shipped as crushed mineral
for special uses. Other colemanite deposits, now idle but mined be-
tween 1900 and 1927, are near Death Valley, m the Calico Mountains
of the Mojave Desert, and at Lang in Los Angeles County, and Frazier
Mountain in the northwest corner of Ventura County (Noble, 1916;
Foshag, 1921 ; Grale 1914b) . One major deposit, discovered by drilling
done for the Geological Survey duruig 1957 but not opened for min-
ing, lies subsurface about 8 miles east of Kramer (Benda, Erd, and
Smith, 1960). This deposit, estimated to contain between 15 and
40 million tons, averages about 14 percent B2O3 (Griswold, 1959).
Borate-bearing horizons in the Death Valley area, if drilled, probably
would be found to contain a comparable tonnage and grade (California
Div. Mines and Geology, 1963). The colemanite deposits offer a
substantial resource for the future.
The colemanite deix)sits are in lake beds of Tertiaiy age. The de-
posits along Furnace Creek, studied by McAllister (1964), are typical.
The largest deposits are in the lower part of the (Pliocene) Furnace
Creek Formation, and are lenses or groups of lenses enclosed in cal-
careous mudstone, sandstone, conglomerate and calcareous chipstone.
The section also contains gj'psiferous beds, some limestone, and in-
trusive basalt in sheets and fragmental masses. Calling the ore "cole-
manite," as customaiy, is misleading, because ulexite and probertite
are major constituents, each occurring as minable masses of one mineral
and also intimately mixed with other borates. Colemanite, in many
places if not everywhere in these deposits, is a replacement mineral.
Most conspicuously, it replaces ulexite, but it also replaces limestone,
forming cross-cutting masses and veins. The ulexite is a dense, mas-
sive variety, unlike the "cottonball" ulexite of recent playa deposits,
and apparently recrystallized. Probertite may also be a replacement
of ulexite ; it is of lower water content. Mining has exposed a zonal
structure in some of the ore, in which colemanite is nearest the sur-
face or envelops ulexite, and probertite is deepest, within ulexite.
The lenticular form of the deposits and their spread along the outcrop
of the lower part of the Furnace Creek Formation suggests accumula-
tion from place to place in an extensive lake, or in a group of shallow
intermittent lakes in an extensive basin. The evidence that the lake
waters were persistently^ calcareous suggests that water containing
sodimn borate entered locally, and that ulexite was precipitated where
waters mixed.
Mhwr deposits
California has several minor deposits which contain no reserves
of significance but do present features of historic and scientific in-
terest. The first borax mined in the United States (1864-1868) was
dug from the bottom mud of Borax Lake, Lake County ( Vonsen and
Hanna, 1936) . Tlie occurrence of coarse borax crystals grown in bot-
tom mud suggests some similarity to the Kramer deposit; also, the
110 MINERAL AND WATER RESOURCES OF CALIFORNIA
precipitation of trona, halite, northupite, and gaylussite in a year
when tlie hike desiccated (1934) suggests simihirity to Searles Lake.
The hike has a small drainage basin, within which there are springs
that presumably supplied borax-bearing water like that of much-
studied springs at Sulphur Bank, 9 miles to the west, which contain
720 ppm of boron ( White, 1957) .
From 1874 to 1907 borax was produced from "marsh" deposits in
Death Valley, Saline Valley (Gale, 1914a), Koehn Lake, and at the
margin of Searles Lake. Such deposits are salt crusts, or efflorescences,
accumulated on top of the muddy surfaces of wet playas. Both borax
and ulexite occur in this environment, accompanied by sodium car-
bonate, sulfate, and chloride saline minerals. The Death Valley floor
obviously receives boron weathered from outcrops of the colemanite
deposits in the adjacent hills. This relationship points to the conclu-
sion that similar solution, transport, and redeposition has been occur-
ring in southeastern California at least since the middle Miocene, with
changes in the pattern of basins and ranges causing boron to move
from one sedimentary section to a new one.
Summary of Boron Resources
Searles Lake and Kramer, the major sources, have reserves large
enough to sustain production at recent rates for 50 to 100 years.
Colemanite deposits, noAv little worked, contain additional large re-
sources potentially workable under favorable economic conditions.
Geologic studies indicate that the borate deposits of California occur
in sections of arid-basin sediments that range in age from Miocene to
Recent. Past drilling lias demonstrated that the major borate de-
posits lie concealed beneath alluvial deposits that cover extensive areas
in the southeastern part of the State, and it is probable that future
drilling will discover additional deposits.
Selected References
Barnard. R. M., and Kistler, R. B., 1965, Stratigraphic and structural evolution
of the Kramer sodium borate ore body, Boron, California [abs.] : Northern
Ohio Geol. Soc, Symposium on Salt, 2d, Cleveland.
Benda, W. K., Erd, R. C, and Smith, W. C, 1960, Core logs from five test holes
near Kramer, California : U.S. Geol. Survey Bull. 1(>45-F, p. 319-393.
Bowser, C. J., 1965, Geochemistry and petrology of the sodium borates in the
nonmarine evaporite environment [abs.] : Dissert. Abs., v. 25, no. 12, pt. 1,
p. 7199.
California Division of Mines and Geology, 1963, California mineral production,
1962 : California Div. Mines and Geology, INIineral Inf. Serv., v. 16, no. 1, p. 8-9.
Christ, C. L., and Garrels. R. M.. 1959, Relations among sodium borate hydrates
at the Kramer deposit. Boron, California : Am. .Tour. Sci., v. 257, no. 7, p. 516-
628.
Clarke, F. W., 1924, The data of geochemistry, 5th ed. : U.S. Geol. Survey Bull.
770, 841 p.
Dub, G. D., 1947. Owens Lake — source of sodium minerals: Am. Inst. Mining
Metall. Eng. Tech. Pub. No. 2235. Mining Technology, v. 11. no. 5, 13 p.
Dyer, B. W.. 1950. Searles Lake development: Colorado School Mines Quart.,
V. 45, no. 4B, p. 39-44.
Flint. R. F., and Gale. W. A., 19.58. Stratigraphy and radiocarbon dates at Searles
Lake, California : Am. .Jour. Sci., v. 256, no. 10. p. 089-714.
Foshag, W. F.. 1921, The origin of the colemanite deposits of California : Econ.
Geology, v. 16, no. 3, p. 199-214.
Gale. H. S., 1914a, Salt, borax and potash in Saline Valley, Inyo County, Cali-
fornia : U.S. Geol. Survey Bull. 540-N, p. 416-421.
MINERAL AND WATER RESOURCES OF CALIFORNIA HI
— — , 1914b, Borate deix)sits in Ventura County California : U.S. Geol. Survey
Bull. 540-0, p. 434-456.
-, 1915. Salines in the Owens, Searles, and Panamint basins, southeastern
California : U.S. Geol. Survey Bull. 580, p. 251-323.
-, 1946, Geology of the Kramer borate district, Kern County, California :
California Jour. Mines and Geology, v. 42, no. 4, p. 325-378.
Griswold, W. T., 1959, Colemanite as an important source of borates : Am. Inst.
Mining Metall. Engineers Preprint No. 59H20.
Johnstone, S. J., and Johnstone, M. G.. 1961, Minerals for the chemical and
allied industries, 2d ed. : New York, John Wiley & Sons, Inc., 788 p.
McAllister, J. F., 1964, Preliminary geologic map of the Furnace Creek borate
area. Death Valley, California : U.S. Geol. Survey open-file map, April 3, 1964,
scale 1 : 24,000.
Miller, W. C, 1964, Boron in Metals and Minerals (except fuels) : U.S. Bur. Mines
Mineral Yearbook 1963, v. 1, p. 317-325.
Noble, L. F., 1926, Note on a colemanite deposit near Shoshone, California, with
a sketch of the geology of a part of Amargosa Valley : U.S. Geol. Survey Bull.
785, p. 63-75.
Schaller, W. T., 1929, Borate minerals from the Kramer district, Mojave Desert,
California : U.S. Geol. Survey Prof. Paper 158-1, 173 p.
Smith, G. I., 1962, Subsurface stratigraphy of late Quaternary deposits, Searles
Lake, California : a summary : U.S. Geol. Survey Prof. Paper 450-C, art. 82,
p. C65-C69.
Smith, G. I., and Haines, D. V., 1964, Character and distribution of nonclastic
minerals in the Searles Lake evaporite deposit, California : U.S. Geol. Survey
Bull. 1181-P. p. P1-P58.
Smith, W. C, 1960, Borax and borates, in Industrial Minerals and Rocks : New
York, Am. Inst. Mining Metall., and Petroleum Engineers, 3d ed., p. 103-118.
, 1962, Borates in the United States, exclusive of Ala.ska and Hawaii : U.S.
Geol. Survey Mineral Inv. Resource Map MR-14.
Sokoloff, V. P., 1964, The mineral industry of the U.S.S.R. : U.S. Bur. Mines.
Minerals Yearbook 1963, v. 4, p. 749-778.
Stipp, H. E., and Schreck, V. R., 1963, Boron in Metals and Minerals (except
fuels) : U.S. Bur. Mines Minerals Yearbook 1962, v. 1, p. 327-343.
Teeple, J. E., 1929, The industrial development of Searles Lake brine : New York,
Chemical Catalog Co.
Ver Planck, AV. E., 1956, History of borax production in the United States :
California Jour. Mines and Geology, v. 52, p. 273-291.
, 1957, Boron to Mineral commodities of California : California Div. Mines
Bull. 176, p. 87-94.
Vonsen, Magnus, and Hanna, G. D., 1936, Borax Lake, California : California
Jour. Mines and Geology, v. 32, p. 99-108.
White, D. E.. 1957. Magmatic. connate, and metamorphic waters : Geol. Soc.
America Bull., v. 68, no. 12, pt. 1. p. 1659-1682.
BROMINE
(By G. I. Smith, U.S. Geological Survey, Menlo Park, Calif.)
Most of the bromine produced in the United States comes from
plants in Texas and Micliigan whicli extract it from sea water and
well brines. Production also comes from oil-well brines in Arkansas,
and from two plants in California. One of these California plants
utilizes sea-water bitterns left over from the solar evaporation of
salt, and the other uses saline brines pumped from Searles Lake.
Bromine is used most extensively m additive compounds for gas-
oline. Smaller quantities are used in the manufacture of fireretarding
and fireproofing materials, fire extinguishers, fumigating mixtures,
sanitizing additi^^es for swimming-pool water, bleaches, photographic
emulsions, laboratory reagents, and medicinal and pharmaceutical
preparations (Miller, 1964).
112 MINERAL AND WATER RESOURCES OF CALIFORNIA
Production of bromine in the United States began in the mid-1800's.
Output was somewhat limited because of competition with the Stass-
furt deposits in Germany, but at the time of World War I, domestic
production rose to 1.7 million pounds per year. By 1929, the wide-
spread use of bromine in gasoline antiknock compounds resulted in
an increase of domestic production to about 6.5 million pounds per
year, and by 1939, production had risen to 37.9 million pounds. Dur-
ing World War II, national production rose to 102.1 million pounds.
By 1963, domestic annual output had reached 203.3 million pounds,
and was valued at $48.5 million (Keiser, 1960) .
Production of bromine in California began in 1926 when plants were
built at Chula Vista and San Mateo to extract bromine from the bit-
terns produced during solar salt evaporation along the edges of San
Diego and San Francisco Bays. The San Mateo plant closed about
1930, and the Chula Vista plant closed in 1945. In 1931, a new plant
was constructed at Newark, on the southeast shore of San Francisco
Bay, by the California Chemical Corp. ; it is now operated by the In-
organic Chemical Division of the FMC Corp. and uses bittern pro-
duced by the Leslie Salt Co. The bittern contains 0.175 percent bro-
mine, and the bromine is recovered during the first step of a process
that also produces magnesia. Since 1940, bromine has also been ex-
tracted from Searles Lake by the American Potash & Chemical Corp.
In that operation, bromine, along with several other products, is ex-
tracted from a complex brine that contains about 0.085 percent bro-
mine. Current production data from these California plants are not
published, but in 1957, their combined output was estimated to be about
2 million pounds of bromine and bromine compounds a year, which
would have been a little over 1 percent of the Nation's total (Ver
Planck, 1957).
In May 1965, bromine was selling for 221^ cents per pound in tank-
car lots; other bromine-bearing chemicals were higher priced (quoted
by the Oil, Paint, and Drug Reporter, May 31, 1965). With prices
in this range, transportation costs are not a large part of the total
price, and producers in most parts of the country and world are able
to compete for available markets.
Future resources of bromine are essentially unlimited because of
the use of sea water as one of the raw materials. California's pro-
duction, however, comes from plants that extract bromine from brines
that may someday become unavailable. The resources in Searles Lake
are presumably large, but bromine production will cease if extraction
of the several other components becomes unprofitable. The plant
using bitterns at Newark is de))endent upon the continued production
of salt, and, as noted in the chapter on Salt, that industry is jeopar-
dized by the population expansion which tends to encourage the con-
version of evaporating pond areas into real estate or other types of
developments.
Selected References
Keiser, H. D., 1960, Minor industrial minerals, in Industrial minerals and rocks :
Am. Inst. Mining Metall. Petroleum Engineers, p. 605-621.
Miller, W. C, 1964, Bromine : U.S. Bur. Mines, Minerals Yearbook, 1963, v. 1, p.
327-332.
Stipp, H. E., 1960, Bromine, m Mineral facts and problems, 1960: U.S. Bur.
Mines Bull. 585, p. 149-154.
Ver Planck, AY. E., 1957, Bromine in Mineral Commodities of California : Cali-
fornia Div. Mines Bull. 176, p. 95.
MINERAL AND WATER RESOURCES OF CALIFORNIA 113
CADMIUM
(By P. K. Morton, California Division of Mines and Geology, Los Angeles, Calif.)
Only in comparatively recent years has cadmimn been recognized
as an important metal to man. During the first 60 years after its
discovei-y in 1817 by F. Strohmeyer, little use was found for the
metal. Most of the important use-development of the metal came
after 1919 with the advent of an electroplating process developed by
M. J. Udy.
The primary uses of cadmium are listed below in the approximate
order of consumption :
1. Plating — 55 to 60 percent. Cadmium is used as a corrosion-
resistant coating on a wide variety of iron and steel products by
electroplating, hot dip, spray, or vacumn plating methods.
2. Cadmium sulfide, sulfoselenide, and lithopone — 15 percent.
Utilized as yellow, orange, and red pigments.
3. Other cadmium compounds — 15 to 20 percent. This cate-
gory includes stearate for vinyl plastics, phosphors for television
tubes, and nitrate for nickel-cadmium batteries.
4. Low melting point fusible alloys such as solders, automatic
fire-sprinkler systems, etc.
A small but important use of cadmium is in cadmium sulfide crystals
which are used in the aerospace industry for solar energy conversion,
in radiation detection devices, and photosensitive elements.
The only known primary sources of cadmiimi are zinc ores, and zinc-
bearing lead and copper ores. Greenockite (cadmium sulfide) is the
principal ore mineral of cadmium, but it rarely occurs except in close
association with sphalerite, a zinc sulfide. Most of the cadmium re-
covered, however, does not occur as greenockite but as a constituent
of zinc minerals — principally sphalerite. Sphalerite has been shown
to contain as much as 4.5 percent cadmium (Rankama and Sahama,
1950, p. 708). Zinc concentrates processed in the United States con-
tain an average of from 0.1 to 1.4 percent cadmium (Schroeder, 1965,
p. 4). California zinc concentrates have yielded an average of 0.22
to 0.28 percent cadmium (Goodwin, 1964, p. 97) .
World production in 1919 was about 200,000 pounds; in 1963 it was
26,300,000 pounds. United States production rose from 131,000
pounds in 1919 to 503,000 pounds in 1925, and increased rapidly to an
average annual production of about 10 million pounds for the five-
year period from 1959 through 1963. Shipments by United States
producers in 1963 totaled 10,124,000 pounds valued at $21,880,000.
Total California production figures are not available, but during
the five-year period ending in 1963 the estimated California cadmium
production was about 5,600 pounds. In terms of the United States
production during the same period this amounts to about 0.01 percent.
The close association of cadmium to zinc results in the unfortunate
circumstance wherein cadmium reserves and production are a function
of zinc reserves and production. In California, cadmium is found in
the lead-zinc ores of the Great Basin province in Inyo and San Ber-
nardino Counties; the copper-zinc ores of the foothill belt in the west-
ern Sierra foothills; and tlie Shasta County copper-zinc district.
(The reader is referred to the zinc section of this volume for further
discussion of these areas.)
114 MINERAL AND WATER RESOURCES OF CALIFORNIA
Selected References
Goodwill, J. G.. 1957. Cadmium, in Mineral commodities of California : Califor-
nia Div. Mines and Geology Bull. 176, p. 97-98.
Hanipel, C. A. 1954, Rare metals handbook : New York, Reinhold Pub. Co., p.
87-103.
Johnstone, S. J., and Johnstone, M. G.. 19G1, Minerals for the chemical and
allied industries : New York, John Wiley and Sons., Inc., p. 103-110.
Mentch, R. L., and Lansche, A. M., 195S, Cadmium, a materials survey: U.S.
Bur. Mines Inf. Circ. 7881. 43 p.
Pendergast, R. A., 1965, Cadmium, market guide, in Eng. and Mining Jour.
Metal and Mineral Markets, May 31, 1965 : New York, McGraw-Hill Pub. Co.,
p. 5-19.
Rankama, Kalervo, and Sahama, Th. G., 1960, Geochemistry : Univ. Chicago
Press, p. 708-714.
Schroeder, H. J., 1964, Cadmium, in Minerals Yearbook, 1963: U.S. Bur. Mines,
p. 333-a40.
, 1965, Cadmium. /» Mineral facts and problems: U.S. Bur. Mines Bull.
630, 9 p.
U.S. Bur. Mines, 1965, Cadmium, /;(■ Commodity data summaries, p. 22-23.
CALCITE, OPTICAL GRADE
(By S. J. Rice, California Division of Mines and Geology, San Francisco, Calif.)
Use and Economic Importance
Transparent and nnflawed calcite (Iceland spar) is made into polar-
izing prisms for use in several types of optical instruments. These
prisms yield very high quality polarized light for such instruments
as polarizing microscopes, metalographs, saccharimeters, dichroscopes,
photometers, colorimeters, and polariscopes. Although the unit price
is high, calcite suitable for these purposes is rare, and only a few hun-
dred pounds at most are used annually. Artificial materials such as
polaroid have been used increasingly as a substitute for calcite polariz-
ing prisms since World War II, but expanding demand for research-
quality instruments should guarantee a ready market for optical-grade
calcite, which is superior to known substitutes for some uses.
Calcite suitable for optical purposes must be transparent, water-
clear, and free from microscopic inclusions, cleavage cracks, or twin-
ning. It must also occur in masses large enough to yield crystals or
cleavage rhombohedra at least about one cubic inch in volume. In
any deposit, the percentage of optical-grade material recoverable is
very low compared to the amount of clear calcite present.
Mineralogy and Geological Occurrence
Calcite (CaCOs) is one of the most common minerals, but only
rarely does it occur in the form of the large transparent crystals called
Iceland spar. It is characterized by highly perfect rhombohedral
cleavage and a hardness of 3, and it effervesces vigorously in dilute
hydrochloric acid. Its value as an optical material is based on its
strong double refraction. This is a property whereby light passing
through a cleavage rhomb is resolved into two separate rays that are
polarized at right angles to each other, and which are refracted at
different angles. The latter phenomenon can be demonstrated by
placing a cleavage fragment of clear calcite over a dot on a piece of
paper and observing that two dots appear.
MINERAL AND WATER RESOURCES OF CALIFORNIA
115
Iceland spar is found lining cavities within discontinuous calcite
veins and pockets that rarely can be traced laterally or downward for
more than a few tens of feet. Although calcite veins occur in many
kinds of rocks, most of the productive deposits in the world are en-
closed in volcanic locks, and appear to have formed during the last
stages of volcanism. Since the late 1930's most of the domestic re-
quirements for Iceland spar have been supplied from such deposits in
the states of Sonora and Chihuahua, Mexico (King, 1946 and 1947;
Fries, 1948). Domestic production has been largely from California,
Montana, and New Mexico.
Occurrences in California
Iceland spar has been mined at three localities in California (see fig.
13). The only one being worked in 1965 is on the western side of
Momit Baldwin, near the head of Convict Creek in Mono Coimty. The
EX PLANATION
Deposit
Figure 13. Oalcite (optical grade) in California.
116 MINERAL AND WATER RESOURCES OF CALIFORNIA
deposits here occur as numerous lenses or huge druses in marble (Mayo,
1934) . The druses are ellipsoidal to irregular in shape, up to about
40 feet in length, and bordered by very coarsely crystalline white cal-
cite. They are lined with large crystals, some up to several cubic feet
in volume, of clear calcite from wiiich the optical -grade material is ob-
tained. Sand and clay fills most of the cavities found, and large crys-
tals that have fallen from the roofs of the cavities are found embedded
in this fill. Optical-grade calcite was discovered in this area prior to
1934, but systematic exploitation was first undertaken bv the U.S.
Calcite Co. in 1963.
An Iceland spar deposit in Modoc County, about 10 miles south of
Cedarville, was mined intermittently in the period 1920-1925 (Hughes,
1931), but has since been idle. The calcite occurs in veins as much as
three feet thick that are in andesite. Individual crystals recovered
from this deposit were relatively small, up to about 12 ounces. About
1,000 ounces of Iceland spar were sold from this deposit in 1920-1921,
probably the mine's most active period.
During World War II, Iceland spar was produced from deposits
on the east side of the Santa Rosa Mountains in San Diego County
and used to manufacture optical ring gunsights (Weber, 1963). Here
the crystals occur with common calcite and gypsum as veins which
filled joints in conglomerate, the largest deposits being at the intersec-
tions of joints. The calcite crystals are unusual in that they are thin
and tabular, being flattened perpendicular to the c axis. Those mined
were as much as 18 inches in diameter and 3 inches thick, but as
trimmed to useable plates they averaged between 2 and 3 inches in
diameter and 14 fo % inches thick. Some 6,000 pounds of Iceland
spar were shipped from this deposit from late 1942 to early 1944, but
not all of it was useable (Wright, 1957) .
The wide geographic distribution of known deposits in California,
as well as the diversity of geological environments in which they are
found, suggest that possibilities are good for finding additional de-
posits in the State. Present marketing conditions, and those of the
foreseeable future, appear to be good for this commodity.
Selected References
Fries, Carl. .Jr.. 1948, Optical calcite deposits of the Republic of Mexico: U.S.
Geol. Siin-ey Bull. 954-D, 179 p.
Gwinn, G. R.. 1945. Mining optical calcite : Min. Cong. Jour., v. 31. no. 5, p. 67-72.
Hughes, H. H., 1941, Iceland spar and optical fluorite: U.S. Bur. Mines Inf. Circ.
6468R, 19 p.
King, C. R., 1946, How a sudden demand for optical calcite was met : Eng. Mining
.Jour., V. 147, no. 5, p. 80-81.
, 1947, Finding and mining optical calcite crystals : Eng. Mining Jour., v.
148, no. 6, p. 94-96.
Mayo, E. B., 1934, Geology and mineral deposits of Laurel and Convict Basins,
southwestern Mono Countv. California : California Jour. Mines and Geology,
V. 30, no. 1, p. 84-85.
Newman, E. W.. 1945. Methods of prospecting and mining optical calcite in
Montana : Am. Inst. Mining Metall. Engineers, Mining Technol., v. 9, no. 6,
10 p.
Weber, F. H., Jr.. 1963. Mines and mineral resources of San Diego County,
California : California Div. Mines and Geology, County Rept. 3, p. .52-.54.
Wright, L. A., 1957, Calcite. optical grade, in Mineral commodities of California :
California Div. Mines Bull. 176, p. 99-100.
MINERAL AND WATER RESOURCES OF CALIFORNIA
117
CALCIUM CHLORIDE
(By G. I. Smith, U.S. Geological Survey, Menlo Park, Calif.)
About a third of the calcium chloride used in the United States is a
by-product of the Solvay sodium carbonate process. The other two-
thirds comes from natural brines. Of this, Michigan produces 95
percent; California, 4 percent; and West Virginia, 1 percent (Babcock,
1964).
The natural brines from which calcium chloride is produced are
generally neutral to slightly acid, and are high in calcium, sodium,
and chloride, but low in carbonate and sulfate as shown in table 10.
The brines used for calcium chloride production in Michigan (table
10, analysis 8) and West Virginia come from wells sunk into Paleozoic
formations. California production comes entirely from late Qua-
ternary deposits in Bristol Lake.
Table 10. — Analysis of waters containing high concentrations of calcium chloride
[Analyses in parts per million; n.d., not determined or not reported]
Ca
Mg
Na
K
CI
Br
SO4
CO3
HCO3
B4O7
NO3
pH
Total dissolved sol
ids (percent)
1
Bristol
Lake
solar
concen-
trated
brine
43, 000
1,074
57, 370
3,303
172, 900
n.d.
210
n.d.
n.d.
30
n.d.
n.d.
27.9
Bristol
Lake
well
brine
17, 190
598
46, 070
1,479
104, 600
n.d.
1,048
n.d.
n.d.
88
n.d.
n.d.
17.1
Cadiz
Lake,
San
Bern-
ardino
County
4,500
410
22, 600
1,040
44, 760
n.d.
280
0
0
n.d.
n.d.
n.d.
7.36
Salton
Sea area
artesian
well.
Imperial
County
14, 400
3,600
18, 400
61, 200
n.d.
200
300
n.d.
990
n.d.
9.91
Salton
Sea geo-
thermal
well,
Imperial
County
40, 000
730
51,000
25,000
185,000
146
56
n.d.
n.d.
1,870
35
ca. 5-6
30.99
6
Oil field
brine,
Raisin
City,
Fresno
County
2,190
832
14,800
251
29,000
108
0
0
193
30
44
6.4
4.76
Oil field
brine.
South
Moun-
tain,
Ventura
County
5,890
69
4,140
117
17,000
91
18
0
17
trace
n.d.
n.d.
2.74
8
Brine
well,
source of
calcium
chloride,
Michigan
74,800
9,960
22,500
9,120
208,000
2,910
40
n.d.
n.d.
1,365
n.d.
n.d.
33.1
1. Durrell, 1953, p. 13, analysis II; brine from drainage canal in salt body. Analysis by W. W. Brannock.
2. Durrell, 1953, p. 13; analysis I; brine from shallow well. Analysis by W. W. Brannock.
3. Gale, H. S., and Hicks, W. B., 1920. Brine from depth of 36 feet. Analysis by Smith, Emery & Co.
4. Recalculated to actual concentrations from data of Coleman, 1929, quoted by Ver Planck, 1957. Well
on Mullet Island.
5. White, D. E. (1965). Analysis by J. D. Hem and others.
6. White, Hem, and Waring, 1963, table 13, analysis 1. Analysis by D. O. Watson.
7. White, Hem, and Waring, 1963, table 13, analysis 2.
8. White, Hem, and Waring, 1963, table 13, analysis 8.
Bristol Lake lies in the east-central part of the Mojave Desert
province (see fig. 67, chapter on Salt). The fill beneath the floor of
this closed depression consists of more than a thousand feet of salt
and clay (Bassett and others, 1959), but the brines abnormally rich
in calcium chloride (table 10, analysis 2) are restricted to the top 32
feet (Gale, 1951, p. 10). Cadiz Lake, in an adjacent basin, contains
a similar but less rich calcium chloride brine (table 10, analysis 3).
Similar brines have also been found in springs and in a geothermal
well in the Imperial Valley of California (table 10, analyses 4
and 5).
118 MINERAL AND WATER RESOURCES OF CALIFORNIA
Geologic explanations for the origin of Bristol Lake brine are not
satisfactory. The brine's characteristics are quite different from those
in most dry lakes, though somewhat similar to those obtained from
some oil fields. Examples of such brines are found in a few Cali-
fornia fields (table 10, analyses 6 and 7) , but better and more common
examples are found in oil field brines of other states that come from
older rocks.
Consumers of calcium chloride in the United States mostly utilize
the tendencies of its solid form to absorb water .and its solutions to
freeze at low temperatures. About 30 percent of the solid calcium
chloride produced is used for deicing road surfaces, 25 percent is for
dust control, 13 percent is for inhibiting the loss of moisture in con-
crete during setting and curing, and 5 percent is for refrigeration.
The rest is used chiefly for freezeproofing bulk shipments of frag-
mental materials, for dustproofing mines and roads, and for dehumidi-
fying. Because of the high density of calcium chloride solutions, it
is .also used in oil-well drilling and as a ballast for tractor tires ( Ver
Planck, 1957 ; Reiser, 1960 ; Babcock, 1964) .
The properties of calcium chloride are uncommon, and for many
years the material was regarded as nearly worthless. Over the last
20 years or so, however, consumers have discovered many new uses,
and established uses have become widespread. For example, in 1962,
production of natural and synthetic calcium chloride in the United
States was 672,000 tons, double the amount produced 10 years earlier
(Reiser, 1960 ; Babcock, 1964) .
In the period 1959-1963, annual production of 75-percent-equivalent
calcium chloride from natural sources averaged about 437,000 tons;
this was valued at $8.32 million, or about $19 per ton. California
production in 1953 was about 16,000 tons (Ver Planck, 1957), and the
State's 1963 share in national production from natural sources shows
that this tonnage has remained about the same.
Most of the product marketed in California is used for the treatment
of ore and seaweed and by the concrete industry, but smaller quan-
tities .are used for dust control, refrigeration, drying operations, and
oil-well drilling (Ver Planck, 1957). California markets have not
grown as fast as those in the rest of the country because they do not
include populous areas affected by winter driving problems.
Producers of calcium chloride from the brines of Bristol Lake are
the National Chloride Co. of America and the Leslie Salt Co. (for-
merly the California Salt Co.). Both companies concentrate the
natural brines (table 10, analysis 2) by solar evaporation until most of
the salt is precipitated and the more soluble calcium chloride is con-
centrated in the solution. Mucli of the brine is sold in that form ; the
rest is sold to the Hill Bros. Chemical Co., located nearby, where it is
converted to solid flake form (Ver Planck, 1957) .
Future production and consumption of calcium chloride are likely
to increase rapidly because ucav uses are being consistently developed.
Natural resources are large. Although not all of it could be recovered
economically, the total amount of calcium chloride in Bristol Lake is
estimated to be enough to last hundreds of years at present production
rates. Additional sources of calcium chloride in California might lie
in Cadiz Lake, in the geothermal brines of the Salton Sea area, and in
oil field brines.
MINERAL AND WATER RESOURCES OF CALIFORNIA 119
Selected References
Babcock, CO., 1964, Calcium and calcium compounds : U.S. Bur. Mines Minerals
Yearbook, 1963, v. 1, p. 311-346.
Bassett, A. M., Kupfer, D. H., and Barstow, F. C. 1959, Core logs from Bristol,
Cadiz, and Danby Drv Lakes, San Bernardino County. California : U.S. Geol.
Survey Bull. 1(>45-D, p. 97-138.
Durrell, Cordell, 1953, Geological investigations of strontium deposits in southern
California : California Div. Mines Spec. Kept. 32, 48 p.
Gale, H. S., 1951, Geology of the saline deposits, Bristol Dry Lake, San Bernardino
Countv, California : California Div. Mines Si)ec. Kept. 13, 21 p.
Gale, H.' S., and Hicks, W. B.. 1920, Potash in 1917: U.S. Geol. Survey Mineral
Resources, 1917, pt. 2, p. 397-481.
Reiser, H. D.. 1960. Minor industrial minerals, in Industrial minerals and rocks:
New York, Am. In.st. Mining Metall. Petroleum Engineers, p. 605-621.
Ver Planck, W. E., 1957, Calcium chloride : California Div. Mines Bull. 176, p.
101-104.
White, D. E., 1965, Saline waters of sedimentary rocks: Am. Assoc. Petroleum
Geologists Mem. 4.
White, D. E., Hem, J. D., and Waring, G. A., 1963, Chemical composition of sub-
surface waters, in Data of geochemistry : U.S. Geol. Survey Prof. Paper 440-F,
67 p.
CARBON DIOXIDE
(By C D. Edgerton, Jr., U.S. Bureau of Mines, Pittsburgh, Pa.)
Carbon dioxide is a colorless, odorless, nonflammable, heavier-than-
air gas commonly found in association with natural gas in subsurface
reservoirs. The concentration of carbon dioxide here may range from
a fraction of 1 percent to nearly 100 percent. It is also fomid m many
volcanic gases, in mineral springs, and in emissions from other phe-
nomena related to geothermal activity. Carbon dioxide occurs in the
earth's atmosphere in concentrations of less than 1 percent.
Carbon dioxide can be readily liquified and solidified. In the latter
state it is known as dry ice, and is an excellent refrigerant. In the
solid state, its temperature is minus 109° F. It passes from the solid
to the gaseous state without going through a liquid phase.
Industry uses carbon dioxide principally in the manufacture of
carbonated soft beverages and as a refrigerant. It also is used in the
preservation of food and other products that would deteriorate if
exposed to air, in fire extinguishers, and as an explosive.
In California, carbon dioxide formerly was produced commercially
from three fields, one in Imperial County and two in Mendocino
County. These fields, however, have not produced for several years.
In 1965, the State's only production of naturally occurring carbon
dioxide came from a plant near Taft, in Kern County, operated by
Tidewater Oil Co. which extracted the product from natural gas
from nearby oil fields. Tidewater sold the carbon dioxide to aircraft
companies for use in freezing rivets, and to bottlers of carbonated
beverages. Another plant in the same area, operated by Standard
Oil Co. of California, extracted carbon dioxide from natural gas,
but the product was not marketed. The latter plant was operated to
upgrade the natural gas by removing the carbon dioxide in order
that the natural gas would meet pipeline specifications.
Although the State's production of naturally occurring carbon
dioxide is, at present, limited to the above, various analyses by the
Bureau of Mines indicate the presence of carbon dioxide in the natural
120
MINERAL AND WATER RESOURCES OF CALIFORNIA
gas from a number of the State's fields. Table II gives the percentage
of natural gas from representative California fields.
Table 11. — Percentage of carbon dioxide in natural gas from representative
California fields
Field
Percent
of carbon
dioxide
Ten Section
Santa Maria
Torrey
Coalinga
McKittrick
West Los Angeles
Midway Sunset. -
Fullerton...
Kem River
Kern
Santa Barbara
Ventura
Fresno
Kings
Los Angeles.. -
Kings
Orange
Kern
0.8
15.5
6.8
11.1
30.4
1.0
10.5
1.7
6.5
Only a small percentage of the carbon dioxide produced in Califor-
nia comes from natural sources. Most of it is produced by calcining
limestone, during the fermentation of alcohol, and as a by-product of
other industrial processes.
Selecsted References
Burrell, G. A., 1911, Analyses of natural gas from the southern California oil
fields, Chapter in Allen, I. C, and Jacobs, W. A., Physical and chemical prop-
erties of the petroleums of the San Joaquin Valley, California : U.S. Bur.
Mines Bull. 19, p. 47-56.
Girdler Corporation, Gas Process Division, 1942, The effective separation of
hydrogen sulfide and carbon dioxide from gases and liquids ; the girbotol
process : Louisville, Ky., 40 p.
Goldman, H. B., 1957, Carbon dioxide, in Wright, L. A., ed., Mineral commodities
of California : California Div. Mines and Geology Bull. 176, p. 105-112.
Gregory, L. B., and Scharmann, W. G., 1937, Carbon dioxide scrubbing by amine
solutions : Indus, and Eng. Chemistry, v. 29, p. 514^519.
Kidde (Walter) and Company, Inc., Aviation Division, 1941, Magic bottles;
the story of compressed gases in aviation, 20 p.
Mason, J. W., and Dodge, B. F., 1936, Equilibrium absorption of carbon dioxide
by solutions of the ethanolamines : Am. Inst. Chem. Eng. Trans., v. 1, p. 27-47.
Miller, R. D., and Norrell, G. P., 1964, Analyses of natural gases of the United
States, 1961 : U.S. Bur. Mines Inf. Circ. 8221, 148 p.
Quinn, E. L., and Jones, C. L., 1936, Carbon dioxide : Am. Chem. Soc. Mon. Ser.
No. 72, 294 p.
CHROMITE
(By T. P. Thayer, U.S. Geological Survey, Washington, D.C.)
Chromite, as the only economic source of chromium, is an essential
commodity for modern industry, and over the last 10 years the United
States has used about 1,200,000 long tons of it annually. About 60
percent of the total is reduced to ferrochromium and used metallurgi-
cally in steel alloys for strength and resistance to corrosion, and ap-
proximately 28 percent is used in high-temperature furnace linings,
especially in the steel industry. The chemical industry consumes the
remaining 12 percent to make dichromate as a basis for dyes, tanning,
and chromium plating. Although magnesite can be substituted for
much of the chromite in refractories, there are no satisfactory substi-
tutes for chromiimi in the metallurgical and chemical industries.
The United States has depended on imported chromite since about
1880 (see fig. 14), and even when imports were interrupted by war
MINERAL AND WATER RESOURCES OF CALIFORNIA
121
1910 1920
1930 1940 1950 1960
Figure 14. — Production of chromite in California since 1885 in relation to total
United States production and consumption, world production, and domestic
price. Note increase in proportion of concentrates in the United States as a
whole, and decreasing peaks in California production during the last three
war periods despite successively higher prices (most data from U.S. Bureau
of Mines Minerals Yearbooks) .
has been unable to obtain as much as half of its needs from domestic
deposits. Total domestic production of 1.9 million long tons is equiv-
alent to about 18 months consumption at recent rates, and Califor-
nia's production of 543,000 long tons would last about 5i/^ months.
Between about 1875 and 1940, before development of large deposits
in Montana, California was the principal domestic source of chromite.
67-164 o — 6&-^t. I-
122 MINERAL AND WATER RESOURCES OF CALIFORNIA
Chromium ores are mixtures of the mineral chromite with gangue
minerals, mostly serpentine and magnetite, in various proportions.
The chromite contains all the chromium in the ore, but in addition
contains variable amount of iron oxide, MgO, and AI2O3 as essential
constituents. The chromium content of an ore depends, then, on two
factors: the ratio of chromite to gangue and the composition of the
chromite mineral. Ores that contain too much gangue can be raised
to usable grade by grinding the ore and separating the chromite from
the gangue by several physical processes, but if the chromite itself
is too low in chromium, commercial grade cannot be attained. Most
California chromite is of the metallurgical type, for which conven-
tional specifications require 48 percent CrsOa, a Cr :Fe ratio of 3 :1,
and Si02 not more tlian about 5 percent; lower grade ores can be
used metallurgically, however, with some loss in efficiency. Before
1940, most ore mined was high enough in grade to ship as lumpy ore
directly or after sorting by hand, but since then most mine-run ores
have been concentrated. Although the High Plateau mine in Del
Norte County has yielded relatively large amounts of lumpy ore
averaging more than 48 percent CraOs with Cr :Fe ratio exceeding 3 :1,
it is exceptional. Shipments from California between 1950 and 1958
were mostly concentrates which averaged 43 to 44 percent CrjOs with
Cr:Fe between 2.6:1 and 2.7:1.
The chromite deposits in California are of two types: irregular
lenticular to tabular bodies of the podiform type (Thayer, 1964) that
occur only in peridotite and serpentinite, and placer or sand deposits.
Beach sands south of Crescent City are known to contain chromite,
but have not been fully explored; they are not believed to be large
(Wells and others, 1946, p. 74) .
The known podiform deposits in California range in size from a
few pounds to about 135,000 long tons of ore, the size of the ore body
that was mined out at the Grey Eagle mine in Glenn County. Many
deposits are of massive ore, with sharp boundaries, but the larger ones
are of disseminated ore and commonly grade into barren rock. The
ore bodies occur individually or in clusters distributed more or less at
random in the peridotite or serpentinite. Most deposits have been
found by surface exposures or by drilling and mining in the vicinity
of exposed ore bodies. In a few places, as in the San Luis Obispo
district (Walker and Griggs, 1953, p. 50), ore bodies are alined along
shear zones. Despite much research, however, no economic method
has been devised as yet for finding the numerous chromite deposits that
must lie just below the ground surface in many parts of the world.
The principal chromite districts of the State (fig. 15) are in the
Klamath Mountains, in the northern Sierra Nevada, and in the
southern Coast Ranges. Two relatively small areas, Del Norte County
and the San Luis Obispo district, have yielded 215,600 long tons of
chromite, nearly 40 percent of the recorded State total, and the 13
largest mines produced 244,700 tons, slightly more than 45 percent
of the State total. Several hundred small mines and prospects are
known. The random distribution of deposits is emphasized by pro-
duction of 10 percent of the State total from two essentially isolated
mines (see fig. 15), the Grey Eagle in Glenn County (Rynearson
and Wells, 1944), and the Butler Estate in western Fresno County
(Matthews, 1961).
MINERAL AND WATER RESOURCES OF CALIFORNIA
123
124°
123°
122°
120°
- I
41°-
Eurvka.
V \ n "Ti
\ V:-^^rfmJ CASCADE
■\ A :)^
NN / BUltE V' WlERRA
Qi rict L Jo — - .
NEVADAl
^0\
ehama
39°+
124°
38
i23°s^:i^^^^i^°^««^
EXPLANAT I ON
Limit of chronite producing area,
dashad nhe r a i nde finite
• 3
Mine or deposit whose production plus remaining
resources is equivalent to 10,000 tons or more
of shipping ore and concentrates
Mine or deposit whose production plus remaining
resources is equivalent to 2,000 to 10,000 tons
of shipping ore and concentrates
Key to principal nines, deposits, or
closely grouped deposits
1 . H igh Pla teau aina
2 . French Hill ulna
+ ,V.
Seiad CreeK (Mountain View) deposit
5 . Little Cast le Creek nine
X 6. Noble Electric Steel group (IO deposits)
'X 118°
UOLUMNE AmONO\ -|-
38°
riposa/ y
/> r s
Bishop 'v
A,
\^
122°
Z. \ r— ' V^ V
'-FRESNffU^ , S
•\pENlTpiL\ -7 ^_vi.\ ^'^
sMONTEREY^l^rX M f TlW>*RE ^ '.I
— 37°
I N Y O ^ \
7. Grey Eagle line (^""^
8. Lambert aine
9. Dobbas aina ,
10. Pillikin a in a (6 daposils)
1 1 . But lar Estate aina
12. Castro aina (10 deposits)
13. Tr inidad-Morcross group
34°
100
I
\
<"■
MOJAVE
as BERNARDINO
4>Y5°
•"Vv-—
w
SAN DIEGO
DESERT ■•>
SIDE (
J
iimferiaC~~-~v^ !
SALTON ) '-=,33°
Figure 15. Chromite districts and principal deposits in California.
The record of chromite production in California since World War
I (fig. 14) clearly shows the impact of declining reserves and in-
creased difficulties in mining. Although many deposits and districts
were then relatively inaccessible, 143,700 long tons was shipped from
the State in the 3 years 1916-1918; the peak year was 1918 when
63,145 tons was produced. In 3 years during World War II (1942-
1944) 124,347 tons was produced, wdth a maximum of 54,420 tons in
1943; but during the Korean War it took 5 years (1953-1957) to
produce 124,342 tons with 31,162 tons as the annual peak. In 1918
the price or ore exceeded $45 for only a short time; in terms of
\
124 MINERAL AND WATER RESOURCES OF CALIFORNIA
1954 dollars, peak realized prices during the three periods 1916-1918,
1942-1944, and 1953-1957 averaged $60, $65 to $75, and $80 to $90,
respectively. During the last two periods, moreover, a market was
assured by Government purchase programs (U.S. Commerce Dept.,
1962, p. 82) ; this was not the case during World War I. During
World War I most of the ore was of the lumpy type desired by
industry, and required only hand sorting. The outstanding chromite
mine during World War II was the Grey Eagle, where the Rustless
Mining Co. obtained 30,806 tons of concentrates averaging 46 percent
CraOs and a Cr : Fe ratio of 2.67 : 1 from ore averaging 13 percent
CraOg,' 33 tons of rock was mined for every ton of concentrates ob-
tained (Dow and Thayer, 1946, p. 9). Comparisons of the sizes of
open pits with production from San Luis Obispo district during the
chromite purchase program of the 1950''s indicates comparable ratios
of waste rock to concentrates. The average price of about $90 per
long ton received for ore averaging 42 to 43 percent CrgOs and a
Cr : Fe ratio of 2.6 to 2.7 : 1 was equivalent, quality considered, to
twice the highest world prices in 1956 and 1957, and 3 or 4 times
the world price in the first half of 1965. When the Government
purchase program ended May 30, 1958, California shipments were
at a, rate of about 35,000 tons a year.
The chromite resources of California were estimated by the U.S.
Geological Survey ^ as equivalent to 100,000 long tons of CrjOs in the
ground or about 210,000 tons of standard metallurgical-grade ore, as of
1956. No overall figures are available on ore reserves when mining
stopped in 1958, but it is unlikely that they equalled a year of produc-
tion. Because of the long-term uncertainty of the Government sub-
sidy, ore was mined as fast as it was found ; future mining will, there-
fore, depend on discoveries. The only known moderately large
chromite deposits are in El Dorado, Siskiyou, and Tehama Counties.
Low-grade disseminated deposits, largely in the Pillikin and Dobbas
mines, in El Dorado County, were estimated (Cater and others, 1951,
p. 108) to contain about 600,000 tons of rock averaging 5 percent
CraOa; concentrates, however, average only about 43 percent CroOa
with Cr : Fe ratio of 1.3 to 2.3 : 1 (Cater and others, 1951, p. 137) . "in
Siskiyou County some 275,000 tons of disseminated ore is known, most
of it in the Seiad Creek (Mountain View) deposit; although the total
CroOs content is equivalent to nearly 40,000 tons of 48 percent concen-
trates, milling tests have not achieved satisfactory recoveries (Engel
and others, 1956, p. 6) . Deposits in the vicinity of North Elder Creek,
Tehama County, were estimated in 1943 (Rynearson, 1943, p. 204) to
contain the equivalent of 24,000 tons of standard ore, but all of Tehama
County shipped only 3,350 tons in the period 1952-1958.
The California potential for production of usable chromite might be
summarized by applying a factor of 75 or 80 percent to the tonnages
given in the following statement of the Materials Advisory Board
( 1959, p. 44) regarding the United States :
Although many miners may disagree, the Government purchase programs
for chromite during World War II and from 1951-1958 give a reliable measure
1 Estimate by T. P. Thayer, Department of the Interior Information Service, press
release, June 5, 1957.
MINERAL AND WATER RESOURCES OF CALIFORNIA 125
of the production potential of the pod deposits. The production record of high-
grade ores from the pod deposits may be summarized as follows :
"Period
Base price (in 1954
dollars)
Annual production of
ores and concentrates
(+ 45 percent CrjOa
in thousands of long
tons)
1942-44 . .
$87
113
Average
13 6-25 7
1952-57.
12 8-29 0
This shows that a base price 32 percent higher and major improvements in
mining technology managed to increase production of high-grade ore by only
10 percent. The depletion of reserves is illustrated by the San Luis Obispo
district in California, where plans were being made late in 1957 to handle 80
tons of rock for every ton of concentrates from an operation expected to pro-
duce about 10,000 tons of concentrates. Although a higher base price might
increase production of the +45 percent ores above the 20,000 tons annually for a
very few years, progressive depletion is inevitable. Lowering specifications
below the last purchase program cutoff (42% CraOa, Cr: Fe ratio of 2: 1) might
double the tonnage, but with high-silica concentrates.
In conclusion, neither the history of chromite mining nor known
chromite reserves indicate that California could provide more than
a small part of our national requirements for chromium. Over the
long term the United States and the free world have little choice but
to depend increasingly on major sources of supply in Southern Rho-
desia, the Republic of South Africa, Turkey, and the Philippines.
Furthermore, the outlook for developing large sources of chromite in
the Western Hemisphere is not encouraging.
Selected References
California Division of Mines, 1946-1965, Geological investigations of chromite in
California : California Div. Mines Bull. 134, published by chapters as follows :
Part I. Klamath Mountains
Chap. I. Del Norte County, by F. G. Wells, F. W. Cater, Jr., and G. A.
Rynearson, 1946, p. 1-76.
Chap. II. Siskiyou County, by F. G. Wells and F. W. Cater, Jr., 1950,
p. 77-127.
Chap. III. Shasta, Tehama, Trinity, and Humboldt Counties, by F. G.
Wells and H. E. Hawkes, 1966.
Part II. Coast Ranges
Chap. I. Northern Coast Ranges, by D. H. Dow and T. P. Thayer, 1946,
p. 1-38.
Chap. II. Southern Coast Ranges, by G. W. Walker and A. B. Griggs,
1953, p. 39-88.
Part III. Sierra Nevada
Chap. I. Tuolumne and Mariposa Counties, by F. W. Cater, Jr., 1948,
p. 1-32.
Chap. II. Calaveras and Amador Counties, by F. W. Cater, Jr., 1948,
p. 33-60.
Chap. III. Tulare and eastern Fresno Counties, by G. A. Rynearson,
1948, p. 61-104.
Chap. IV. El Dorado County, by F. W. Cater, G. A. Rynearson, and
D. H. Dow, 1951, p. 105-167.
Chap. V. Northern Sierra Nevada (Placer, Nevada, Sierra, Yuba, Butte,
and Plumas Counties) by G. A. Rynearson, 1953, p. 169-323.
Engel, A. L., Shedd, E. S., and Morrice, E., 1956, Concentration tests on California
chromite ores : U.S. Bur. Mines Rept. Inv. 5172, 10 p.
Jenkins, O. P., 1942, Economic mineral map of California, No. 3 — Chromite:
California Div. Mines map vpith text.
126 MINERAL AND WATER RESOURCES OF CALIFORNIA
Materials Advisory Board, 1959, Report of the panel on chromium, in Report
of the Committee on Refractory Metals : Natl. Acad. Sci. Natl. Research
Council, Rept. MAB-154-M1, v. 2, p. 25-47.
Matthews, R. A., 1961, Geology of the Butler Estate chromite mine, southwestern
Fresno County, California : California Div. Mines Spec. Rept. 71.
Rynearson, G. A., and Wells. F. G., 1944, Geology of the Grey Eagle and some
nearby chromite deposits in Glenn County, California : U.S. Geol. Survey
Bull. 945-A, p. 1-22.
Thayer, T. P., 19G4, Principal features and origin of podiform chromite de-
posits, and some observations on the Guleman-Soridag district, Turkey : Econ.
Geology, v. 59, p. 1497-1524.
U.S. Bur. Mines Minerals Yearbook for various years.
U.S. Commerce Dept., 1962, Materials Survey, Chromium : Business and Defense
Sen- ices Adm., 96 p.
Wells, F. G., Page, L. R., and James, H. L., 3940, Chromite deposits of the
Pilliken area, Eldorado County, California: U.S. Geol. Survey Bull. 922-0,
p. 417-460.
Wells, F. G., Smith, C. T., Rynearson, G. A., and Liverm'ore, J. S., 1949, Chromite
deposits near Seiad and McGuffy Creeks, Siskiyou County, California : U.S.
Geol. Survey Bull. 948-B, p. 19-62.
CLAY
(By F. R. Kelley, California Division of Mines and Geology, San Francisco,
Calif.)
The term "clay" is a broad one, and has been used to include many
diverse materials. In general, it "implies a natural, earthy, fine-
grained material which develops plasticity when mixed with a limited
amount of water" (Grim, 1953). The term commonly is used both in
referring to a definite group of silicate minerals, and as a rock term
to indicate detrital rocks of the smallest grain size (less than about
four microns) , regardless of the composition of the particles. Grim
distinguishes between "clay minerals" and "clay materials", and the
latter is a useful term under which many of our industrial clays
would fall.
Wet mud can be molded and shaped, and will dry to a hard mass
that will have considerable strength, as long as it is not again sub-
jected to moisture. Developing plasticity in a clay by the addition
of water is a reversible process, which can be repeated at will. But
if the clay body is subjected to prolonged and intense heating its char-
acter is changed, and it becomes hard and immune to further attack
by moisture. These are the characteristics of clay which account for
much of its usefulness.
The clay minerals characteristically are hydrous alimiinum silicates,
with other elements such as magnesiimi, iron, potassium, sodium, and
calcium in some of them. Most of them are "layer-silicates", with
sheet-like lattice structures resembling the micas. Based on chemical
composition .and crystalline structure, three main groups are dif-
ferentiated, as follows :
kaolinite group
montmorillonite group
hydrous mica or illite group
Various other minerals, such as attapulgite, sepiolite and the mixed-
layer clays have clay-like properties, but do not fit into the three
groups mentioned.
mineral and water resources of california 127
Classification
Because clays have been utilized for so many purposes over ,a long
period and are such a diverse group of materials, many other classi-
fications have been used in their description. Geologically, clays may
be classified on the basis of their origin as residual, i.e., formed in
place, and sedimentary, i.e., transported from their place of origin.
The terms high-alumina clay and ferruginous clay refer to chemical
composition; refractory clay and semiplastic clay refer to physical
properties; brick clay and bleachmg clay refer to use. No single
classification will serve all purposes.
For gathering statistical information, the U.S. Bureau of Mines
employs a classiiication based on industrial use, as follows:
kaolin or china clay
ball clay
fire clay, including stoneware clay
bentonite
fuller's earth
miscellaneous clay
Much information is cataloged imder this classification, and it .affords
a convenient standard.
Kaolin or china clay
These clays are composed largely of kaolinite, but may have much
quartz, mica, feldspar, or other material from the parent rock still
present. Wliite kaolins are used in whiteware bodies and other high-
grade ceramic uses, and as fillers and coating materials in papermak-
ing. Kaolins also are used as fillers in rubber .and linoleum, and in
various chemical, medicinal, and cosmetic applications.
Ball clay
The important characteristic of the ball clays is their high plasticity
and bonding power. They are composed largely of poorly crystalline
kaolinite and are very fine grained. They are used in blending with
other clays to enhance their workability in manufacturing ceramic
products such as sanitary ware, wall tile, and the like.
Fire and stoTieioare clay
These are made up primarily of kaolinite-group minerals, but vary
widely in composition. Their most important property is refractori-
ness (high resistance to heat), and they are subdivided into several
classes on the basis of a test known as the pyrometric cone equivalent.
Clays above cone 19 (P.C.E. 19, about 1,520°C or 2,T68°F) on this
scale are regarded as fire clays. They are further designated as low
duty, ranging from 19 to 28 ; medium duty, from 29 to 30 ; high duty,
from 31 to 32 ; and super duty 33 (about 1,745 °C or 3,173°F) or above.
Fire clays vary widely in plasticity, and the fired color may vai-y from
near-white to red. They are used in a variety of ceramic products,
ranging from common brick to art pottery, sewer pipe, and orna-
mental tile. Some of the best grades go into refractory brick for use
in the steel industry. Some low-grade fire clay is used in the manu-
facture of stoneware.
128 MINERAL AND WATER RESOURCES OF CALIFORNIA
Bentonite
The term "bentonite" is a rock name, originally applied to a highly
swelling clay material in Wyoming and other Rocky Mountain states.
This clay is derived from the alteration of volcanic ash and is com-
posed principally of montmorillonite. Many bentonites are non-
swelling, and it has been established that only montmorillonites hold-
ing sodium as an exchangeable ion will swell conspicuously, but if this
ion is replaced by calcium, the material loses its swelling properties.
The bentonites are the most reactive of the clays, and are useful as
plasticizers, absorbents, binders, pelletizers, filtration and clarification
aids, ion exchange media, reservoir sealers, and drilling muds.
Fuller's earth
Fuller's earth is a nonswelling bentonitic material also composed
principally of montmorillonite. It is a highly absorptive clay, and
owes its usefulness to its ability to absorb various organic molecules
in the purification of mineral and vegetable oils, and a variety of other
uses.
Miscellaneous clay, including shale
This group takes in a variety of clay materials, including the low-
grade alluvial clays, shales, many soil materials, and any argillaceous
material that does not fit into one of the other groups. Natural clay
materials are usually mixtures, and the less pure clays of any of the
groups may be classified as miscellaneous clays. Any of the clay min-
erals may be present, plus other detrital minerals, including quartz,
mica, the feldspars and others, as well as rock fragments and organic
matter. The miscellanous clays have a variety of uses. For specific
purposes, they are upgraded by blending with higher quality clays to
develop certain properties. Large quantities of miscellaneous clays
go into the manufacture of heavy clay products, such as coimnon brick,
structural tile, and sewer pipe. For this purpose, the clay must de-
velop some plasticity but must not shrink excessively, and must fire to a
suitable color and strong texture at reasonably low temperatures.
Organic matter in a clay material may cause bloating, and large
amounts of bloating clays are used in the manufacture of expanded
shale lightweight aggregate. Large tonnages of common clays of
suitable bulk composition go into the production of portland cement, as
a source of alumina and silica. Smaller amounts are used as fillers for
various purposes, rotary drilling muds, and a variety of other uses.
Geologic Ocgubrence of Clays
The clay materials are secondary, forming as alteration products
of pre-existing rock materials by weathering processes or hydrother-
mal alteration, or in some cases by diagenetic processes. The more
soluble constituents of the original rocte are leached out, leaving be-
hind the relatively stable aluminum silicates which are refomied as
clay minerals. If the alkalis and alkaline earths are not completely
removed, the clay minerals formed may be montmorillonites or illites.
Kaolinite appears to represent a more advanced stage of clay forma-
tion. Under severe chemical weathering, the kaolinite itself may break
down, leaving only a residue of aluminum and iron oxides, such as in
the lateritic soils of the tropics.
MINERAL AND WATER RESOURCES OF CALIFORNIA 129
Clay deposits may be residual or transported, according to their
relationship with neighboring rock bodies. Residual clays are formed
when chemical weathering alters the surface rocks to appreciable
depths. Such weathering is most active under warm, moist climatic
conditions, and if removal of the weathered residues by mechanical
erosion is slow, a weathered zone of considerable depth may be
developed.
If the clay, once formed, is removed and transported elsewhere, it
may be laid down as a sedimentary clay deposit. These are usually
interbedded with other sediments, but the clays tend to stay in suspen-
sion until finally they settle out in sheltered basins of relatively quiet
water. Sedimentary clays commonly are associated with lignite, de-
rived from the thick vegetation of marshy areas bordering the basins.
In California, the fire clays of the lone and Alberhill areas are sedi-
mentary clays associated with white sands and lignite. Warm, moist,
semitropical climates prevailed in these areas during parts of the
Paleocene and Eocene Epochs, and mantles of residual clay were devel-
oped on the alumina-rich bedrock of the low-lying land areas. Much
material was eroded from these residual zones, and deposited in
lagoons, swamps, and along the shallow margins of the adjacent seas
to form these sedimentary clay deposits.
Hydrothermal clays are formed when hot, chemically active waters
rise through fissures and leach the soluble constituents out of the sur-
rounding rocks, leaving a residue of kaolinized wallrock. The altered
zone will be of limited lateral extent and will grade outward into fresh
rock, but it may extend to considerable depth.
Bentonite deposits appear to have formed by the alteration of vol-
canic ash beds. Volcanic glass is unstable, and the transformation to
montmorillonite takes place as carbonate- and acid-rich groundwater
percolates through the fine-grained mass. Similar changes occur
during the diagenesis of many sediments, as the action of ground water
causes the formation of authigenic clay minerals within the sedimen-
tary material.
History or Discovery and Development
As the early gold seekers spread through central California, they
also foimd other mineral materials of potential value, including coal
and clay, but the beginnings of clay mining are not well documented.
At first, the recovery of useful clays was incidental to early coal-mining
operations, which were carried on at several localities, including Mount
Diablo, Corral Hollow and Carbondale, in the lone area. One of the
earliest potteries in the State was at Antioch, using clay from the
Black Diamond Coal mine.
At Corral Hollow, coal mining had started by 1858, and high-grade
clays of the district became the basis for a thriving clay industry which
operated until 1912, when it was discontinued due to high mining costs.
The Dosch pit north of lone was opened up in 1864 and is the oldest
continuously operating clay pit in the State. In 1865, the clays of the
lone district were mentioned in the reports of the State Geological
Survey. The Gladding, McBean mine and plant at Lincoln began
operations in 1875 and has operated continuously since that date. In
130
MINERAL AND WATER RESOURCES OF CALIFORNIA
southern California, coal mining at Alberhill dates from 1882, and clay
production from 1895.
In the early days of the State, destructive fires had resulted in a de-
mand for bricks, and local brickyards were established in many of the
towns throughout the State. In the last few decades, as transporta-
tion improved, many of these small operations became uneconomic and
have passed out of existence ; now, most of the brick manufacturing is
done near the larger population centers.
The demand for a variety of clays and clay products continues, and
clay production in California is at an all-time high.
California Clay Production
Clay materials are common and widespread, and are utilized in
many countries of the world, but no overall, world-wide production
figures are available. During 1963, the United States produced over
50 million tons of clay of all types, valued at about $181 million (see
table 12). In general, clay production is largest in the more indus-
trialized nations. Considering kaolin and china clay production
alone, the United States is the source of about 36 percent of the world
production of over 8,757,000 tons, followed by the United Kingdom
andU.S.S.R.
Table 12. — U.S. and California clay production, 1963
Kaolin
and china
clay
Ball clay
Fire clay
Bentonite
Fuller's
earth
Miscel-
laneous
clays
U.S. production (tons)
U.S. production (dollar value;
California production (tons)..
California production (dollar
value)
California percent of U.S.
total
California rank among States
(dollar value)
Price per ton (average U.S.)..
3, 163, 573
59, 770, 274
18, 941
297, 989
0.5
3 5(?)
$ll-$68
547, 668
7,541,471
(')
(')
♦(?)
$8-$22
8, 390, 174
39, 557, 870
531, 390
1, 920, 589
4.9
55
$4.71
1, 584, 516
18, 536, 229
14,444
2 282, 928
2 1.7
64
$11. 70
481. 817
11, 210, 618
(')
(■)
'(?)
$23.27
3d, 031, 254
44, 257, 364
2, 800, 900
5, 165, 419
11.7
1
$1.20
' Unapportioned.
valued at $363,910.
2 1962.
3 Georgia 1st.
* Tennessee 1st.
5 Ohio 1st.
« Wyoming 1st.
' Florida 1st.
Combined production of ball clay and fuller's earth for California was 29,608 tons ,
In 1963, California's production of all clays totalled 3,395,281 tons,
valued at $8,030,830, and based on dollar value, it ranked fifth among
the states, as follows :
Percent of total value U.S. production
Georgia 30.0
Pennsylvania 8. 1
Ohio 7.7
Wyoming 6. 3
California 4.4
Of California's mineral commodities in 1963, clay was ninth in dollar
value at 0.5 percent of the total, or if mineral fuels are excluded it
ranked sixth, at 1.6 percent, behind cement, sand and gravel, stone,
MINERAL AND WATER RESOURCES OF CALIFORNIA 131
boron and lime. Production of clay was reported by 65 companies,
from about 100 properties, in 34 different counties. About one-quarter
of this production was fire clay, and nearly two-thirds Avas miscella-
neous clay, of which 41 percent went into portland cement, 29 percent
into expanded shale aggregate, and 30 percent into heavy clay products
and other uses.
California Deposits
Fire clay deposits
Fire clays of good quality have been mined in several districts in
California (see fig. 16) . Along the western foothill belt of the Sierra
Nevada, the sedimentary formations of the Great Valley overlap on
the gently sloping Mesozoic bedrock surface. In many places, the
oldest rocks of the Great Valley sedimentary sequence are light-colored
sandstones and clays of Eocene age, known as the lone Formation.
These sediments are well exposed over a 2 by 12 mile area near lone,
in Amador County, where they are made up of clayey sandstones,
clays, siliceous gravels, conglomerates and lignite, of variable tliick-
ness and lithology. The clays are kaolinitic, and occur in lenses up
to 30 feet thick. The formation dips gently westward and is overlain
by tuffaceous sediments of Miocene age. The fire clays of this district
have been used in refractories and heavy clay products for many years,
and recently high-grade clays and glass sand have been recovered
from the clayey sandstones.
Elsewhere along the foothill belt, to the northwest and southeast,
there are occasional exposures of the lone Formation, as at Lincoln,
in Placer County, a major source of fire clays for 90 years. Other
localities include Michigan Bar, Folsom, Valley Springs, Knight's
Ferry, and Cooperstown, where some of the recent production has
been ball clay, usable as a blending material in the manufacture of
wall tile and other products.
The lone beds dip into the synclinal trough of the G;reat Valley,
and, west of the valley, beds of comparable age and lithology are
exposed at several places. At Tesla, in Alameda County, coal and
clay were mined from these beds for many years, but the beds dip
steeply, and large-scale open-pit mining is not possible. For this
reason, mining operations were stopped many years ago, although
some of the clays were of excellent quality.
In southern California, a major zone of high-grade fire clays occurs
in western Riverside County, from the Alberhill area northwest to
Corona, and around the northern end of the Santa Ana Mountains into
Orange County. During Paleocene time, the Mesozoic crystalline bed-
rock of the area was deeply weathered, with the development of
residual clays, and some of these were removed and deposited with
Paleocene beds of the Silverado Formation. Sandy beds are inter-
stratified with the sedimentary clays, and in many places the Silverado
is overlain by several feet of Quaternary conglomerate.
Alberhill and the Corona area have been major sources of clays for
refractories and heavy clay products for many years. In the Clay-
mount area west of Corona, mining of highly refractory clays began
in 1925. A new major clay deposit was opened up south of Corona
in 1954.
132
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANATION
Kao I in or china clay
O
Ba 1 1 clay
A
Fire clay
Q
Ben ton j te
Ful ler's earth
M Jscel laneous clay
MOJAVE -p^s-
FiGtTBE 16. Clays produced in California.
In southern Orange County, near El Toro, small amounts of high-
grade kaolins are recovered by washing a clay -sand mixture from the
Silverado Formation.
Bentonitic clay deposits
Many deposits of bentonitic clay material are scattered over the
southern part of California. They occur in rocks of various ages,
but the majority are Tertiary.
South of Owens Lake, near Olancha, is an important source of non-
swelling bentonite. This clay is derived from a tuff, altered by hydro-
thermal solutions, and occurs as a low-dipping bed about 16 feet thick,
beneath a layer of basalt. It is classed as a fuller's earth, and is used
as a filtering and decolorizing agent.
In San Benito County, bentonitic beds occur near the base of the
Kreyenhagen Shale, exposed in the steeply dipping south flank of the
MINERAL AND WATER RESOURCES OF CALIFORNIA 133
Vallecitos syncline. This material has been used as a reservoir and.
canal sealer, and some has been used as an insecticide carrier.
Near Hector, in San Bernardino County, a unique swelling ben-
tonitic material is mined. It is high in magnesia, low in silica, and has
a small lithium content, and is derived from an altered basic tuff or
flow in a lake bed sequence. It resembles Wyoming bentonite in its
swelling properties, and has been extensively used in rotary drilling
mud. After beneficiation, some is used in pharmaceuticals and bever-
age clarification.
Bentonite is being mined at several other localities, including Death
Valley Junction, Tecopa, Brawley, and Vidal.
Other deposits
Clay deposits in the Hart area, eastern San Bernardino County,
have been mined for more than 40 years. These clays were formed by
hydrothermal alteration of Tertiary rhyolites. Some of them are
classed as kaolins and others as ball clays, and they are used in pottery,
sanitary ware, and wall tile.
In southeastern Mono County, high-grade kaolin is produced from
a deposit near Casa Diablo. This clay is a hydrothermally altered
tuff, occurring in a horizontal deposit up to 25 feet in thickness.
Some of this clay is sold as a filler in papermaking.
Common clay deposits
Common clays are abundant in California, and large tonnages of
alluvial clays and shales are mined annually near population centers,
for use in heavy clay products such as building brick. Often the
common clays are blended with others to make higher grade ceramic
products. Large quantities are also used in making portland cement
and expanded shale aggregate. Nearly every county in the State
has produced common clay in the past.
Resource Potential and Future Prospects
No detailed information on California's clay reserve and potential
resources is available, and only rather broad estimates can be made.
Each of the several types of clay is a separate entity, and, furthermore,
the use of a given clay material may depend more on relatively obscure
and subtle physical properties than on its general classification; so
there w^ould be many special cases to consider in any detailed estimate.
Kaolin. — California's resources are small, and large amounts are
brought in from outside sources. There is some chance for discovery
of new deposits, but perhaps the best means to improve the California
position is research to find new ways of using some of the lower
grade kaolinitic clays.
Ball clay. — This follows the pattern of kaolinite, with small Cali-
fornia production and large imports brought in from Kentucky and
Tennessee. However, there appear to be moderate resources of ball
clay available and, as time goes on, the local material should find wider
acceptance and use as additional testing on its properties is done.
Fire clay. — Reserves appear to be satisfactory, except for the most
refractory grades of fire clay. Additional fire clay can probably be
found by drilling programs, based on careful studies of sedimentary
trends. The State's known small deposits of super-duty refractory
134 MINERAL AND WATER RESOURCES OF CALIFORNIA
clay have been depleted, and this clay is now imported. Careful
exploration and drilling might find new small deposits of super-duty
clay, but probably far short of enough to meet needs.
Bentonite and fuller's earth. — Intensive prospecting and testing
probably would bring to light more deposits of usable bentonite of
many diverse types. However, the outlook appears to be unfavorable
for finding large resources of Wyoming- type swelling bentonite.
Common clay. — Large resources appear to be available. However,
urbanization around the population centers will restrict the use of
some deposits, and recovery operations will be forced further away as
the cities expand.
Selected References
Carlson, D. W., and Clark, W. B., 1954, Mines and mineral resources of Amador
County, California : California Jour. Mines and (Jeology, v. 50, no. 1, p. 149-285.
Cleveland, G. B., 1957, Clay, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 131-152.
Cooper, J. D., 1963, Clays: U.S. Bur. Mines Minerals Yearbook, 1963, v. I,
p. 393-418.
, 1965, Clays, in Mineral facts and problems, 1965 ed. : U.S. Bur. Mines
Bull. 630, preprint, 14 p.
Dietrich, W. F., 1928, The clay resources and the ceramic industry of California :
California Div. Mines Bull. 99, 383 p.
Gray, C. H., Jr., 1961, Mines and mineral deposits of the Corona South quad-
rangle : California Div. Mines Bull. 178, p. 59-120.
Grim, R. E., 1953, Clay mineralogy : New York, McGraw-Hill Book Co., Inc.,
384 p.
, 1962, Applied clay mineralogy : New York, McGraw-Hill Book Co., Inc.,
422 p.
Klinefelter, T. A., and Hamlin, H. P., 1957, Syllabus of clay testing : U.S. Bur.
Mines Bull. 565, 67 p.
U.S. Bur. Mines, 1965, Commodity data summaries. Clays, p. 32-33.
COAL
( By E. R. Landis, U.S. Geological Survey, Denver, Colo. )
Of the total energy' consumed in the United States in 1963, 22 per-
cent was furnished by coal. Only oil, with 41 percent, and gas, with
33 percent, outpaced coal (U.S. Bureau of Mines, 1964a, p. 50). Over
half of the coal produced in 1963 in the United States was burned to
generate electricity, almost 19 percent was used to produce coke, about
24 percent was used industrially, and about 6 percent went for retail
deliveries (U.S. Bureau of Mines, 1964a, fig. 14) . Only a very small
amount of coal is mined in California but 1,690,000 tons were shipped
into the State from Utah and New Mexico in 1963 to make coke for
smelting steel and for other industrial uses (U.S. Bureau of Mines,
1964b).
Coal is an organic sedimentary rock composed of metamorphosed
plant material admixed with a subordinate amount of inorganic con-
stituents. The plant material may have accumulated at its growing
site or may have been transported by water and wind to its deposi-
tional site. Peat is excluded by definition because it is not metamor-
phosed, but it is the material from which coal is derived. Coal
results when peat is buried and progressive changes in physical
and chemical properties take place, mainly related to time and
weight of overlying sediments. In places the changes are speeded
MINERAL AND WATER RESOURCES OF CALIFORNIA 135
by pressure from structural deformation or heat from igneous intru-
sive rocks. The progressive metamorphism increases the carbon con-
tent and heat vakie while decreasing the moisture and volatile matter
contents. Coals are classed by rank, according to the degree of meta-
morphism, from lignitic to subbituminous, bituminous, and anthracitic,
and the rank is generally an index to the usability and value of the
coal (table 13). Anthracitic coal is largely used for domestic and
other space heating, but some is blended with bituminous coal to make
coke. Bituminous and subbituminous coal range widely in properties
but in general the higher rank coal is likely to be used for special pur-
poses, such as making metallurgical coke, and the lower rank coal is
likely to be used solely for heat energy, as in steam-electric utility
plants. Lignitic coal is largely used as a source of heat energy but
carbon, industrial gases, humic acid compounds with a great variety of
uses, and montan wax are also derived from lignite.
Coal deposits range in shape from thin beds of wide extent, to thick
nearly equidimensional bodies. As with other stratified rocks, the
shape and attitude of coal beds are affected by the deforming forces,
folding, faulting, and igneous intrusion. For profitable development
under present-day conditions with a high degree of mechanization,
coal beds mined underground should be 3i/^ feet or more thick with a
small range in thickness, flat-lying, not broken by faults, and at depths
of less than 1,000 feet. In surface, or strip, mining the additional
important factors are thickness and character of the material over-
lying the coal bed — the coal should be less than 100 feet below the sur-
face and the overburden should be easily removable.
In 1963, the United States mined 16 percent of the world coal out-
put, about 477 million tons, and ranked third in production behind
the U.S.S.R. with 584 million tons and Germany (East and West)
with 559 million tons (U.S. Bureau of Mines, 1964a, p. 168-170).
First recorded production of coal in California was in 1855, and the
annual coal production exceeded 100,000 tons during most years be-
tween 1867 and 1903 (Jennings, 1957, p. 153). The coal was used for
steam generation by the railroads and steamships, and for industrial
and domestic heating. Oil and gas began to displace coal as a heat
source shortly after 1900 and by 1914 annual coal production was a
few thousand tons. In recent years the amount of coal produced an-
nually in California has probably been a few thousand tons, almost
all of which is used as a raw material from which montan wax and a
few by-products are derived. Montan wax is used in shoe polishes,
floor waxes, electrical insulation, leather dressings, inks, carbon paper,
protective coatings and waterproofing compounds, greases, phono-
graph records, rubber, investment castings, and many other allied
products (Jennings, 1957, p. 162). Almost all of the coal imported
into California is carbonized to make coke and by-product chemicals.
Only 37,000 tons of the total 1,690,000 tons that were shipped from
Utah and New Mexico went to retail deliveries and other uses (U.S.
Bureau of Mines, 1964b) .
Small, scattered deposits of coal are reportedly present in 43 counties
of the State but have been mined or intensively prospected at less
than a dozen localities in 11 counties (Jennings, 1957, p. 153) (fig. 17) .
136
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA
137
EXPLANAT I ON
o
ch
"''amounts of coal have been mined
^-— A---r \^i. Areas in which significant
Other areas mentioned in text
^TEHAMA ""t:^ /^, ,.„. ''^,;
yr '°' X
i,ENN)Bt\rrX'^-,p:;^„rtj Coal reported (Jennings. 1957.
Qi \ /X'.-^'::i^Ji: fig.1: and U.S. Bureau
of Mines. 1947. fig 2)
Figure 17. Coal in California.
The following brief discussion is derived largely from Jennings (1957)
and the U.S. Bureau of Mines ( 1947) .
High- volatile bituminous coal is present in the Temblor ( ?) Forma-
tion of early and middle Miocene age in the Stone Canyon district of
southeastern Monterey County, and some bituminous coal occurs in
rocks of Eocene age in southern San Benito County. The bitumi-
nous coal in the Stone Canyon district may be of the variety known
as cannel coal, which characteristically has as much or more volatile
matter as carbon and is noncoking (U.S. Bureau of Mines, 1947, p. 4) .
Subbitmninous coal and lignite occur in the Montgomery Creek Forma-
tion in Shasta County, in the Te^la Formation in Alameda County,
and in the Domengine Formation in Contra Costa County. These
three rock units are all Eocene in age and are probably partially or
67-164 O — 66— pt. I-
-10
138
MINERAL AND WATER RESOURCES OF CALIFORNIA
completely equivalent to each other. Subbituminous coal is also pres-
ent in the Temblor Formation of Miocene age in Mendocino County
and in rocks of Eocene age in Siskiyou County. Lignitic coal occurs
in rocks of Early Cretaceous age, and in the Weaverville Formation
of Oligocene (?) age in Trinity County; in the Silverado Formation
of Paleocene age in Riverside and Orange Counties, though the avail-
able incomplete analysis suggests that some or all of this coal may be
subbituminous ; and in the lone Formation of Eocene age in Amador
County.
The coal beds of California do not range widely in age, and the
differences in rank are due largely to differences in amount of struc-
tural deformation that the deposits have undergone. The coal-bearing
rocks in the Coast Ranges have been folded and faulted and the coal
has commonly been metamorphosed to higher ranks than the coal in the
foothills of the Sierra Nevada and in the Peninsular Ranges where the
strata dip gently or are horizontal (Jennings, 1957, p. 153) (table 14) .
Table 14. — Range of
analyses of representative California coals, as-received basis
Sample source
Num-
ber
of
sam-
ples
Rank (table 13)
Moisture
(percent)
Volatile
matter
(percent)
Fixed
carbon
(percent)
Ash
(percent)
Sulfur
(per-
cent)
Calorific
value (B.t.u.
per pound)
Stone Canyon,'
Monterey County.
Mount Diablo,'
Contra Costa
County.
Corral Hollow,'
Alameda County.
Alberhill,3 River-
3
1
2
1
2
High volatile B
bituminous.
Subbituminous
A.
Subbituminous
B.
Lignite A * or
subbitumin-
ous C.
Lignite A
4. 4- 8. 0
15.0
17. 6-18. 0
19.0
40. 3-45. 8
44. 8-50. 0
38.4
39. 2-41. 1
46.5
30. 9-31. 3
30. 3-36. 0
34.5
23. 3-26. 4
21.9
13. 2-15. 7
7. 5-15. 9
12.1
16. 4-18. 0
12.6
7. 6-15. 2
4. 1-4. 6
5.6
2. 9-3. 1
11, 420-12, 130
9,240
2 8, 110
side County.
lone, Amador '
County.
1. 0-1. 3
5, 640- 6, 060
1 U.S. Bureau of Mines (1947).
2 Only 1 calorific value reported.
3 Jennings (1957) .
* Reported to be lignite; but may be subbituminous.
Significant quantities of coal have been mined in only five areas —
Mount Diablo in Contra Costa County, Corral Hollow in Alameda
County, Stone Canyon in Monterey County, Alberhill in Riverside
County, and lone in Amador County (fig. 17). Total recorded pro-
duction to date is about 5,310,000 tons, of which about 3,500,000 tons
was mined in the Mount Diablo district between 1855 and 1902 (Jen-
nings, 1957, p. 153). Of the remainder, at least 350,000 tons were
mined in the Corral Hollow district between 1897 and 1902 (Jennings,
1957, p. 157).
According to Karp (1949, p. 341), the known coal resources of Cali-
fornia are estimated to be more than 100 million tons, of which
Averitt 1961, p. 85) estimates about 50 percent is lignitic coal, 40
percent subbituminous, and 10 percent bituminous. The general
assumption that for every ton of coal actually produced another ton
has been lost in mining or is unrecoverable is probably valid for areas
such as California where precise information is unavailable.
MINERAL AND WATER RESOURCES OF CALIFORNIA 139
Selected References
American Society for Testing Materials, 1964, Proposed revised tentative specifi-
cations for classification of coals by rank (ASTM Designation: D388-T).
Averitt, Paul, 1961, Coal reserves of the United States— A progress report, Jan-
uary 1, 1960: U.S. Geol. Survey Bull. 1136.
Jennings, C W., 1957, Coal, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 153-164.
Karp, S. E., 1949, California coal : Compass, v. 26, p. 341-344.
U.S. Bureau of Mines, 1947, Analyses of Arizona, California, Idaho, Nevada, and
Oregon coals : U.S. Bur. Mines Tech. Pai>er 696.
U.S. Bureau of Mines, 1964a, Mineral Yearbook, 1963, v. 2, Fuels, p. 49-174.
, 1964b, Bituminous coal and lignite distribution. Quarterly, March 1964.
COBALT
(By J. T. Alfors, California Division of Mines and Geology, San Francisco,
Calif.)
Cobalt compounds have long been used to give a beautiful blue color
to pottery and to glass. This ancient use still pei"sists, but the re-
markable ability of cobalt metal to impart great strength to alloys
at high temperatures, and magnetic qualities to certain alloys, has led
to increased use of cobalt in the past 20 years. Recently, other refrac-
tive metals have partially replaced cobalt for high-temperature super-
alloys and the amount of cobalt used for permanent -magnet alloys
also has declined on account of substitutes (U.S. Bureau of Mines,
1965, p. 39).
The domestic consumption of cobalt in 1963 was 10.5 million pounds,
7 percent less than 1962. The major uses of cobalt were for high-
temperature, high-strength alloys (23 percent) and for permanent-
magnet alloys (22 percent). Uses in steel (12 percent) and other
products brought the total consimiption of metallic cobalt to 75 per-
cent. Nonmetallic (exclusive of salts and driers) consumption,
mainly m pigments and as ground-coat frit, was 13 percent of the
total. Sales and driers account for 12 percent of the domestic con-
sumption (Ware, 1964, p. 2-3) .
Cobalt is generally recovered as a by-product of copper or nickel
ores. Some cobalt is obtained during the processing of iron, gold,
lead, and silver ores. Other metals associated with cobalt include
zinc, manganese, uranium, platinum, and chromium (Vhay, 1952, p.
VI-5, 6; Centre dTnformation du Cobalt, 1960. p. 8-29).
The important primary ore minerals of cobalt are skutterudite
((Co,Ni,Fe)As3), carrollite (C00CUS4), limiaeite (C03S4), and co-
baltite (CoAsS). The principal cobalt minerals in the oxidized zone
of mineralization are asbolite (a cobalt-bearing mixture of hydrous
manganese and iron oxides), heterogenite (a hydrous oxide of cobalt
and copper), sphaerocobaltite (C0CO3), and eiythrite (Co3(As04)2"
8H2O) (Bilbrey, 1960, p. 216; Centre dTnformation du Cobalt, 1960,
p. 8-10).
Cobalt deposits commonly are associated with mafic or ultramafic
igneous rocks as magmatic segregations of sulfides or as vein or re-
placement deposits formed by hydrothermal activity. Cobalt-bearing
vein deposits are less commonly associated with granitic rocks. Cobalt
is concentrated to economic grade in some lateritic soils developed on
140
MINERAL AND WATER RESOURCES OF CALIFORNIA
serpentinized peridotite and other ultramafic rocks. A good summary
of the geology of a large nmnber of cobalt deposits is given by Vhay
(1952,p.VI-5toVI-54).
The Centre d'Information du Cobalt (1960, p. 1-7) has summarized
the history of cobalt since its use in ancient Persia and Egypt. From
the 16th century until 1874, cobalt was produced chiefly in Norway,
Sweden, Saxony, and Hungary. The lateritic cobalt ores from New-
Caledonia were the main source of cobalt from 1874 until 1904 and
thereafter the silver-cobalt-arsenic veins of Ontario, Canada, provided
virtually all of the world's supply. Extraction of cobalt from the
copper ore deposits of Katanga, Belgian Congo (now Republic of the
Congo) began in 1924 and since 1940 Union Miniere du Haut-Katanga
has been the largest producer of cobalt in the world. Other major
cobalt producers are Canada, Morocco, and Northern Rhodesia.
^ s 1 s K 1 1 y o\u
\M(ib^tvi,TAfl'Ns/\ "T"
S^"5H OmoJoc !
Eurvk^ "^ \ "i
t'
/
— •^
PULMAS ^^ ao-
-ft LAKE -.l 'i Vi) V ■,»<<>> _• :
VSONOMAV^N^lL'. _ >,^,„\ ^- ^alpine' ^
EXPLANAT I ON
1 . Ma r J ohn pros pec t
2. Ju I ian-Cuyamaca area
\
SANTA S'T fT ^ .-^ ^ y ~
X
iNTEREY '1 \ V ; TiVaRF ^ A
. " tin; ■*— \ BakemfuW
- l^ omspo
% X-
\
\
*'+' r ^'**'-"f^H-'^. Jl/__ y SAN BERNARDINO •;^
121°
150 Milts
^"^N^V^^^T^r A DESERT j
■^\ —
sanT)~-"
IIMPF.RIAC
rsM-TON
(*^ROUG_H|>^
Figure 18. Cobalt in California.
MINERAL AND WATER RESOURCES OF CALIFORNIA 141
The Betlilehem CornAvall Corp, has recovered cobalt from pyrite
associated with the Coriuvall, Pennsylvania, magnetite ore since 1940,
and in 1963 was the only domestic producer mining cobalt (Ware,
1964, p. 1 ) . From 1952 to 1959, the Calera Mining Co. produced cobalt
from the Blackbird district of Idaho. The National Lead Co. re-
covered cobalt at Frederickstown, Missouri, from 1955 to 1961.
Minor occurrences of cobalt -bearing minerals liave been reported
from numerous localities in California (Murdoch and Webb, 1956,
p. 52, 60-61, 76, 123, 146, 260-262, 301 ; 1960, p. 11, 13-14, 19), but there
has been no commercial production of cobalt in the State. A few tons
of cobalt ore were mined at the Mar John property (fig. 18) in
Calaveras County in 1924 but were not marketed (Chesterman, 1956,
p. 165). A list of California occurrences of cobalt is given by Vhay
(1952, p. VI-38, VI-39, VI-54) but most of them are very small
deposits. Any future production of cobalt in California would un-
doubtedly be as a by-product in the mining of copper, nickel, or iron
ore. The areas with most potential are the copper deposits of the
Foothill Copper Belt of the Sierra Nevada and the Friday nickel
deposit, Julian-Cuyamaca area, San Diego County.
SELECTEa) Refesiences
Bilbrey, J. H., Jr., 1960, Cobalt, in Mineral facts and problems, Anniversary
Edition : U.S. Bureau of Mines Bull. 585, p. 213-224.
Centre d'Information du Cobalt in collaboration with the staff of Battelle
Memorial Institute, 1960, Cobalt monograph : Centre d'Information dti Cobalt.
Brussels, Belgium.
Chesterman, C. W., 1956, Cobalt, fn Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176, p. 165-168.
Murdoch, Joseph, and Webb, R. W., 1956, Minerals of California : California
Div. Mines Bull. 173, 452 p.
, 1960, Supplement to minerals of California for 1955 through 1957 : Cali-
fornia Div. Mines Bull. 173, suppl., 64 p.
U.S. Bureau of Mines, 1965, Commodity data summaries.
Vhay, J. S., 1952, Cobalt Resources, m Materials survey — cobalt: National Secu-
rity Resources Board, 148 p.
Ware, G. C, 1964, Cobalt, Minerals Yearbook, 1963, U.S. Bureau of Mines,
preprint.
COPPER
(By A. Robert Kinkel, U.S. Bureali of Mines, San Francisco, Calif., and Arthur
R. Kinkel, Jr., U.S. Geological Survey, Washington, D.C.)
Copper is one of the most versatile and widely used metals. Its
superior electrical conductivity and alloying characteristics are re-
sponsible for its importance in the industrial economy. About half of
all copper consumed is for electrical applications and about 40 percent
is used for alloy manufacture, largely brass. The automotive industry
uses 30 to 40 pounds per vehicle and accounts for about 9 percent of
the copper consumed in the United States. In addition to its role in
copper-base alloys (brass and bronze), copper is an important con-
stituent of a large number of alloys having a metal other than copper
as the principal component (McMahon, 1965).
The world is adequately endowed with sources of copper. New
discoveries and extensions of mines in many copper provinces of the
world during the 1950's greatly increased the known world copper
142 MINERAL AND WATER RESOURCES OF CALIFORNIA
resources. In addition to the primary sources of copper metal, a large
reserve of secondar^^ copper (scrap) has been accumulated and is con-
tinually being augmented. The collection and processing of this scrap
into secondary metal constitutes an important segment of the copper
industry in all major consuming countries.
Since World War II there has been considerable change in copper
mining technique. In 1939, when the average copper ore mined con-
tained 1.29 percent copper, 59 percent of the copper output came from
open-pit mines. In 1963, when the average ore mined contained 0.74
percent copper, 81 percent of the ore was from open-pit mines. The
trend is toward very' large, but low-grade deposits that can be mined
by highly mechanized methods, and thus at low cost. Most California
copper deposits have been medium sized to small deposits that require
underground mining, and thus are less favorable for mining miless
the grade of the ore is high.
California's copper production has been an important economic
asset in the past, although it was moderate by national standards.
California accounted for over 15 percent of the national total, from
1862 to 1866, and for over 5 percent in 1867-1868, 1901 and 1909.
During years of peak copper production (1909, 1916, and 1924), the
State accounted for about 3 percent of the national total. During
1906-1918 the value of the State's copper output exceeded $10 million
annually (see fig. 19).
The principal copper deposits of California occur in five areas.
These are: 1) the counties of the northern Coast Ranges; 2) Shasta
County; 3) Pliunas County; 4) the Foothill copper belt, which ex-
tends from Butte Comity south to Fresno County ; and 5) the southern
counties of Inyo, San Bernardino, San Diego, and Imperial. By
far the largest part of the copper produced in California has been
from massive pyrite-type ores. Silver and gold are the major by-
products of California copper ores. Sulfur and iron from pyritic
copper ores could be produced if economic conditions were favorable.
History and Production
The mining history of California began with the discover}' of gold
in 1848, although copper had been produced previously from a few
small deposits in Los Angeles County. Exploration following the
discovery of gold resulted in the discovery of many base-metal de-
posits, and copper production began in Calaveras Coimty in 1862, and
soon after in Amador County. Mines of Calaveras County eventu-
ally became the largest producers in the 250-mile- long Foothill copper
belt. Production from this belt virtually ceased during 1868-1881,
for the gold and silver content of the surface-enriched ores decreased
on reaching the primaiy sulfide zone and would no longer support the
cost of shipping the ore to smelters in Wales. Durmg the early 1880's
production was revived in the Foothill belt for a short, period, and
between 1902 and 1960 there was almost continual, although small,
production from one or more mines along the belt. Foothill belt pro-
duction was 4,700 tons of copper in 1917, a level not approached in
later years (see fig. 20).
Copper was discovered in Plumas County shortly after production
began in the Foothill belt and small amounts were produced inter-
MINERAL AND WATER RESOURCES OF CALIFORNIA
143
CO
OS
o
00
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'a
t-l
o
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a
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C3
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.
.
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CD
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in
to CO
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144
MINERAL AND WATER RESOURCES OF CALIFORNIA
200.000
CO
100,000
EX PLANAT I ON
Shas t a
Coun ty
PI umas
County
Foothill
Belt
Other
Areas
^/..
. L-^ 1 ,
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CD r~
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en
FiGUEE 20. California copper production by decades, 1862-1964, showing produc-
tion of major districts.
mittently from 1865 to 1869. The first significant production began
in 1914, and by 1925 output reached 13,500 tons of copper. Copper
mining virtually ceased in Plumas County after 1941 when the Walker
mine (No. 21, fig. 21) was closed.
The East and West Shasta districts (Nos. 10 and 11) did not begin
copper production until about 1894 but by 1896 were the principal
source of copper. A peak production of 25,000 tons was attained in
1909. Mines of the East and West Shasta districts produced a total
of slightly over 10,000 tons annually between 1906 and 1918 from local
smelters. With the exception of the period 1924-1929 and a short
period during World War II, production rates have not since been
significant.
Copper production in other areas of the State has been relatively
small. Minor copper was produced in the northern Coast Ranges (in
Del Norte, Humboldt, Siskiyou, and Trinity Counties) in the 1860's
and 1870's, but reached significant proportions from Siskiyou and
Trinity Counties from 1915 and 1930 and again in Siskiyou County
from 1943 to 1945. Small tonnages were produced perioclically from
central and southern Coast Range counties. Pyrite mines in Alameda
County (No. 60) have a reported output of 284,000 tons of copper-
bearing pyrite from 1901 to 1925 ; this ore was mined mainly for sulfur
MINERAL AND WATER RESOURCES OF CALIFORNIA
145
but it probably contained about 4,000 tons of copper, part of which
was recovered.
The bulk of the copper in California was produced during 1891-1930
as shown in table 15 and figure 20. The significance of Shasta, Plumas,
and the Foothill belt counties production is tliown on figure 20 and
table 15.
Table 15. — Copper production in California, 1862-1964
BY YEARS
Years
Short tons
Thousands
of dollars
1862-90 .
15,700
542,600
78,700
4,400
8,900
1891-1930 - -
176.300
1931-€0
22,400
1961-64 - -
2,600
Total
641,300
210, 100
BY COUNTIES
County
Short tons
Percent of
State total
Shasta .
335,500
162, 700
81,000
21,800
40.300
53
Plumas
25
Foothill belt counties.. . . ._
13
Northern Coast Ranee counties -
3
others - - --
6
Tota'
641,300
Since the mid-1950's the bulk of the copper produced has been
obtained as a by-product in processing tungsten ore at the Pine Creek
mine (No. 62), Inyo County and from numerous polymetallic mines
in Inyo and San Bernardino Counties. The principal localities are
listed in table 16.
Shasta District
The East and West Shasta districts account for about 53 percent of
the copper produced in California. Nine mines produced copper in
the West Shasta district and three in the East Shasta district. In
both districts the large copper- and zinc-bearing massive pyrite de-
posits contain minor gold and silver. Ore bodies in the West Shasta
district are generally large flat-lying lenses essentially concordant
with bedding in felsic volcanic flows and pyroclastic rocks of Devonian
age (Kinkel, Hall and Albers, 1956). Ore bodies in the East Shasta
district are smaller, steeply dipping, and are lenticular to vein-like
or tabular (Albers and Eobertson, 1961). They are also essentially
concordant with foliation and generally with bedding in felsic vol-
canic flows and pyroclastic rocks of Triassic age. In both areas the ores
are in the uppermost parts of thick piles of submarine volcanic rocks
which are overlain by argillic marine sediments. The rocks in both
areas are moderately folded and metamorphosed, and locally they are
strongly sheared.
Ore in the West Shasta area is mainly massive pyrite that contains
several percent copper in parts of the ore but less than half of one
percent copper in other parts. Some of the ore was mined mainly for
146
MINERAL AND WATER RESOURCES OF CALIFORNIA
its sulfur content. Zinc is erratically distributed, but some of the ore
contains more than 10 percent zinc. The ores generally have a zinc :
copper ratio of about 2:1, but most of the zinc was not recovered.
Cadmium occurs in appreciable quantities but was not recovered.
Insoluble material, mainly quartz and sericite, ranges from 3 to 5 per-
cent in most of the ore. Ore in the East Shasta district is also a massive
pyritic zinc-copper ore that contains minor gold, silver, galena., and
tetrahedrite, and has a gangue of barite, quartz, sericite, and anhydrite.
Ore bodies of the East Shasta district are generally smaller than those
of the West Shasta district but are of higher grade.
122
EX PLANATI ON
S hor t tons of c oppe ;
50 to 1 .000
1 ,000 to 50. COO
50.000 to 100.000
Over 100.000
FiGUKE 21. Principal copper localities in California by size categories based on
production plus metal remaining in the deposits (numbers refer to table 16).
MINERAL AND WATER RESOURCES OF CALIFORNIA
147
Table 16. — Principal copper localities in California
County
Del Norte.
Siskiyou. .
Humboldt
Shasta
Trinity..-.
Tehama...
Plumas.. -
Butte
Nevada...
Placer
El Dorado
Amador...
Calaveras.
Tuolumne
Mariposa
Madera
Fresno
Tulare
Alameda
Mono
Inyo.
San Bernardino
San Diego.
Imperial...
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
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
District or mine
Wimer District.
French Hill District.
Gray Eagle Mine.
Blue Ledge Mine.
Klamath River District.
Scott River District.
Do.
Copper BluS Mine.
Horse Mountain District.
West Shasta District.
East Shasta District.
French Gulch District.
Redding District.
MinersviOe District.
New River District.
Mad River District.
Island Mountain Mine.
Tom Head District.
Colyear Springs District.
Lights Creek District.
Genesee District.
Red Rock District.
Saw Pit Flat District.
Inskip District.
Big Bend Mine.
Meadow Lake District.
Foothill Belt, Boss-San Juan Mine.
FoothiU Belt, Mineral Hill Group.
Foothill Belt, Spenceville Mine.
Foothill Belt, Dairy Farm Mine.
Foothill Belt, VaUey View Mine.
Foothill Belt, El Dorado Copper Mine.
FoothiU Belt, LUyama Mine.
Foothill Belt, Funnybug Mine.
Foothill Belt, Noonday Mine.
Foothill Belt, Cosumnes Copper Mine.
Foothill Belt, Big Canyon Mine.
Foothill Belt, Copper Hill Mine.
Foothill Belt, lone Copper Mine.
Foothill Belt, Newton Miae.
Foothill Belt, Penn Mine.
Foothill Belt, Nassau Mine.
Foothill Belt, Quail HiO Mine.
Foothill Belt, CopperopoUs Group.
Foothill Belt, Napoleon, Collier Mines.
Foothill Belt, Oak Hill Mine.
Foothill Belt, Salambo Mine.
Foothill Belt, La Victoria Mine.
Foothill Belt, Blue Moon Mine.
Foothill Belt, Pocahontas.
Foothill Belt, Green Mountain Group.
Foothill Belt, Buchanan Mine.
Foothill Belt, Jesse Belle, Daulton Mines.
Foothill Belt, Krohn Mine.
Minarets District.
Foothill Belt, Painter Mine.
Foothill Belt, Fresno Copper Mine.
Foothill Belt, Copper King Mine.
Camp Wishon District.
Ahna, Leona Mines.
Lundy District.
Pine Creek Mine.
Loretto Mine.
Clark Mountains District.
Ivanpah Mountains District.
Providence District.
Signal District.
Needles District.
Whipple Mountains District.
Turtle Mountains District.
Buckeye District.
Fry Mountains District.
Ord Mountain District.
Ramona District.
Julian District.
Ogilby District.
148 MINERAL AND WATER RESOURCES OF CALIFORNIA
Lights Creek and GsTiesee districts
Plumas County contains three major deposits and numerous small
deposits. At the Engels and the Superior mines in Lights Creek
district (No. 20) the ore occurs as steeply dipping replacement veins
and stockworks in granitic rock. Sulfides are mainly bornite and
chalcocite (Anderson, 1931). At the Walker mine in the Genesee
district the ore occurs as seams, stockworks, and disseminations of
chalcopyrite, chalcocite, and pyrrhotite in schistose rocks (Knopf,
1935). The Engels and Superior mines were closed in 1930 and the
Walker mine in 1941.
Foothill copper helt
The Foothill copper belt extends along the west flank of the Sierra
Nevada batholith. At least 40 copper-zinc mines have been operated
along this narrow 250-mile-long belt but only a few have produced
large amounts of copper and zinc. The Foothill belt contains folded
and metamorphosed sedimentary and volcanic rocks of Paleozoic and
Jurassic age (Heyl, 1948). Along the ore zone the rocks are inter-
bedded felsic and mafic volcanics and related pyroclastic rocks and
intrusives, and marine shales that are in part altered to slate. The
degree of metamorphism is variable but generally increases toward
the south along the belt. Most ore bodies appear to be in the upper
part of a thick, partly submarine, volcanic pile, the Amador Group
of Middle and Late Jurassic age, which is overlain by the Mariposa
Slate of Late Jurassic age.
In the Foothill copper belt the ores are massive sulfide made up
mainly of pyrite; they contain chalcopyrite and sphalerite and
small amounts of gold and silver. The sparse gangue minerals are
quartz, barite, sericite, and chlorite. Ore occurs as steeply dipping
lenticular or tabular bodies in siliceous, sericitic, and pyritic zones,
and ore bodies are peneconcordant with both schistosity and bedding.
In the southern part of the belt where the metamorphism is of hi^gher
grade along the ore zone as in Madera and Fresno Counties, pyrrhotite
is more common and in places exceeds pyrite in abundance. Some
deposits contain minor galena, tetrahedrite, bornite, and cobalt. At
the Jesse Belle mine (No. 53) in Madera County part of the ore
contained up to 0.3 percent cobalt.
The Penn mine (No. 41) is the largest copper-zinc deposit in the
Foothill belt. Individual ore lenses at this mine have a steep pitch-
length of as much as 1,000 feet, a breadth from 100 to 400 feet, and a
thickness of as much as 30 feet. This mine has produced about 40,000
tons of copper and over 6,000 tons of zinc. Zinc exceeds copper in
the ore but was not recovered during most of the period of operation
(Heyl, Cox, and Eric, 1948) .
The eastern part of the Foothill belt (locally known as the East
belt) contains many small but rich vein and replacement deposits of
bornite and chalcocite in metamorphic and igneous rocks, generally
in a quartz gangue.
Other districts
The southernmost copper districts are in Inyo, San Bernardino, San
Diego, and Imperial Counties, which lie within the Basin and Range
MINERAL AND WATER RESOURCES OF CALIFORNIA 149
province. This province is characterized by a thick accumulation of
Paleozoic carbonate rocks with interbedded slates and quartzites; these
are block faulted. The mineral deposits occur as veins and replace-
ment deposits of complex lead-zinc-copper ores in carbonate rocks. In
the western and southern parts of the area, intrusive and metamorphic
rocks become increasingly connnon with little change in the mineraliza-
tion apart from increasing gold content in the western deposits and
copper in the southern deposits.
Several copper deposits in the noithern Coast Kanges have been im-
portant producers in the past. Deposits occur largely as vein, replace-
ment, and disseminated deposits in folded and faulted sedimentary
rocks and in felsic and mafic volcanic rocks. Chalcopyrite, chalcocite,
or bornite, with variable amounts of sphalerite, are the common min-
erals. The deposit of massive cupriferous pyrite at Island Mountain
(No. 17), Trinity County, lias been one of the largest producers of
copper m the area ( Averill, 1941) . Native copper is reported in small
amounts throughout the Coast Ranges. The only significant sulfide
producers in the southern part of the Coast Ranges have been the Alma
and Leona deposits of copper-bearing massive pyrite in Alameda
County (Davis, 1950).
Reserves and Potential Resources
A numbei of inactive copper deposits in California are known to
contain sufficient ore to support moderate production rates for several
years. These resources are small by national standards, and many
deposits would be difficult to mine under present economic conditions
liecause of the cost of mine rehabilitation, transportation, and other
factors. The resource potential of copper in California lies in undis-
covered ore bodies in a number of areas that are favorable for ex-
ploration with modern techniques.
Known or reasonably assured copper resources are mainly in five
areas. These are: 1) Shasta County; 2) Foothill copper belt; 3) Plu-
mas County; 4) northern Coast Ranges; and 5) Minarets district.
The known copper resources of California total about 470,000 tons of
copper.
Practically all of the copper mined in California has come from
deposits that were exposed at the surface. There are geologic reasons
for believing that undiscovered ore bodies should be present in a num-
ber of areas, and based on past production, these should be of sufficiently
high grade to warrant mining. Ore bodies in two of the most produc-
tive'areas, the Shasta district and the Foothill belt, are not marked by
broad alteration halos or other features that give surface clues to the
presence of ore that may exist a short distance beneath the surface.
Exploration for subsurface ore bodies can be limited to certain zones
or horizons by geologic study that will give information on the
processes of ore deposition, but this must be followed by the geo-
physical and geochemical techniques that have been developed so
rapidly in the past decade but have not yet been applied in most of
these areas. Past production and geology of the Shasta, Foothill, and
other promising areas suggest that many copper ore bodies wiU still
be discovered in California.
150 MINERAL AND WATER RESOURCES OF CALIFORNIA
Technical and Marketing Problems
Almost all of California's copper has come from underground
mines. Those in the Shasta area are in rocks that generally allow
open unsupported stopes, but some support of the walls is generally
required in the steep ore bodies in schistose rock along the Foothill
belt. Principal deterrents to mining are the generally small size of
the ore bodies except for a few in the West Shasta district, the fine
grinding required by many of the massive pyritic ores, and high
transportation costs to smelter's. Discovery of adequate reserves would
encourage the establishment of centrally located mills, although anti-
pollution requirements discourage local smelting.
Many treatment and marketing problems are encountered by pros-
pective copper producers in California. Although California is a
major consumer of copper products, the market for rolled, shaped, or
alloyed products is now supplied by imports or from secondary sources.
The nearest copper smelters treating non-company ores and concen-
trates are at Tacoma (Washington), Anaconda (Montana), Hayden,
Superior, and Douglas (Arizona). The freight rates to any of these
plants from California deposits are prohibitive for all but the higher
grade ores.
An increasingly serious problem confronting all mining enterprises
is the reluctance of State and Federal agencies to look favorably on
any enterprise which might impair the esthetic value of possible
recreational and scenic areas. Antipollution legislation will continue
to be important economically in California mining. These factors
all increase the cost of mining, but none would be prohibitive if re-
serves of adequate size and grade could be found.
Selected References
Albers, J. P., and Robertson, J. F., 1961, Geology and ore deposits of the East
Shasta copper-zinc district, Shasta County, California: U.S. Geol. Survey Prof.
Paper 338, 107 p.
Anderson, C. A., 1931, The geology of the Engels and Superior mines, Plumas
Gounty, California (with a note on the ore deposits of the Superior mine) :
California Univ. Dept. Geol. Sci. Bull., v. 20, no. 8, p. 293-330.
Averill, C. V., 1941, Mineral resources of Trinity County : California Jour. Mines
and Geology ,v. 37, no. 1, p. 23-24.
Davis, F. F., 1950, Mines and mineral resources of Alameda County : California
Jour. Mines and Geology, v. 46, no. 2, p. 279-348.
Heyl, G. R., 1948, Foothill copper-zinc belt of the Sierra Nevada, California, in
Copper in California : California Div. Mines Bull. 144, p. 11-29.
Heyl, G. R., Cox, M. W., and Eric, J. H., 1948, Penn zinc-copper mine. Calaveras
County, California, in Copper in California: California Div. Mines Bull.
144, p. 61-84.
Jenkins, O. P., and others, 1948, Copper in California : California Div. Mines
Bull. 144, 429 p.
Knopf, Adolph, 1935, The Plumas County copper belt, California. Copper re-
sources of the world : "Washington, 16th Internat. Geol. Cong., v. 1. p. 241-245.
Kinkel, A. R., Jr., Hall. W. E., and Albers, J. P., 1956, Geology and base metal
deposits of the West Shasta copper-zinc district, Shasta Coimty, California :
U.S. Geol. Survey Prof. Paper 285, 156 p.
McMahiOn, A. D., 1965, Copper, a materials survey: U.S. Bur. Mines Inf. Circ.
8, 225, 340 p.
Southern Pacific Company, 1964, Minerals for industry, v. 2-3, 449 p.
U.S. Bureau of Mines, 1910-1931, Mineral resources, copper and state chapters :
U.S. Bur. Mines.
, 1932-1964, Minerals Yearbook, state chapters.
MINERAL AXD WATER RESOURCES OF CALIFORNIA 151
DIATOMITE
(By G. B. Cleveland, California Division of Mines and Geology, Los Angeles,
Calif. )
Diatomite (Kieselgiilir) is the commercial name for a unique sedi-
mentary rock called diatomaceous earth. This rock consists almost
wholly of fine-grained particles of an inert form of silica, similar
chemically to the mineral opal. The particles range in size generally
from a few to a few hundred microns; each particle is essentially flat,
commonly perforated, and all the particles are loosely packed to yield
a highly porous and permeable material. This combination of prop-
erties makes diatomite an efficient medium for the rapid filtration of
industrial solutions. Filtration lias been the principal use of diato-
mite, and, in 1965, this use accounted for about half of the United
States production; about one- fourth was consumed as fillers, one-
twentieth for lieat and sound insulation, and the balance distributed
among some of the three hundred known uses, such as absorbents,
lightweight aggregate, pozzolan, abrasives, pesticide carriers, and
ceramics.
Geology
Diatomaceous earth is an accumulation of fossils. The fossils are
mainly of diatoms, a class of minute plants that live in water; unlike
most terrestrial plants, they are simple, one-celled form of largely
floating (plankton) organisms. The shape and ornamentation of
the diatom shell (frustule), which is the most diverse imaginable,
is the main basis for separating the many thousands of species knowm.
Being aquatic, diatoms occur in waters throughout the world, but
their remains accumulate as diatomaceous earth only in ocean or lake
basins where ecologic conditions support enormous numbers of indi-
viduals. Cool, clear, well-lighted water promotes the growth of
diatoms, but more important is a constant source of chemical nutrients
to replenish those; taken out of solution during the growth of the
diatom community.
The principal lacustrine deposits of the State all lie in volcanic
terranes, and the common association of volcanic ash with diato-
maceous earth in both marine and lacustrine strata is well estab-
lished. Volcanic processes appear to play a significant part in the
formation of diatomaceous earth, and this relationship can best be
demonstrated for deposits of lacustrine origin and near-shore deposits
of marine origin. During volcanic episodes, established drainage
systems commonly are dammed by lava flows, and new basins may be
created atop the flows themselves ; these may ultimately fill with water
and form lakes. Lakes, being infinitely smaller systems than oceans,
are much more sensitive to slight chemical and physical changes.
Chemical nutrients essential to diatom growth are not readily sup-
plied to streams feeding lake watei*s during normal weathering and
erosion. However, solutions, and emanations accompanying vol-
canism, and ranging widely in chemical composition and concentra-
tion, may be introcluced into lake waters, enriching them in those
elements necessary for diatom growth. Chief among these elements
is silica which the diatom uses in building its shell. Silica is presumed
to be supplied both by silica-rich hydrotheraial solutions and by the
chemical oreakdown of volcanic ash. Ash deposited directly into a
lake breaks down chemically and provides a ready source of silica,
152 MINERAL AND WATER RESOURCES OF CALIFORNIA
while a long-term supply is derived from subaerially deposited ash,
which is carried by streams into the lake basin during subsequent
erosion of adjacent highlands. Among the several other elements
required by diatoms, the concentration of nitrogen and phosphorus is
considered a limiting factor in diatom growth because of the relative
paucity of these elements in lake and ocean water.
Recent work has shown that the volcanic environment is not a req-
uisite for the fonnation of thick marine diatomaceous sediments.
Studies indicate that, in the Gulf of California, the concentration of
silica, and presumably other nutrients, is replenished periodically and
diatoms flourish. The subsequently formed sediments are of purity
comparable to those of California's principal commercial diatomite
deposits. The nature of diatomaceous earth formed in a marine en-
vironment differs somewhat from that formed in a lacustrine environ-
ment. Generally, each habitat supports a diatom flora indigenous to
it, and relatively few diatoms flourish in both marine and lacustrine
waters. Moreover, marine deposits generally comprise a wider vari-
ety of species. An individual deposit of either marine or lacustrine
origin may have an advantage over the other type in certain com-
mercial applications, but suitable material from both kinds of deposits
has been successfully processed for all the principal uses. Generally,
the marine deposits have proven to be a more abundant and versatile
source of material for a wider range of applications than have those
of lacustrine origin.
Diatomaceous earth is light colored, generally gray to white, but
commonly ivory, pale pink, pale green, yellowish-brown, or dark
brown. Diatomaceous earth, being composed principally of opaline-
like silica (Si02*nH20), is a relatively inert rock soluble only in
strong acids or alkalies. Commonly clay and volcanic ash are main
impurities, with some silica sand, calcium or magnesium carbonates,
and iron oxides or iron carbonates present. The pH ranges from about
4.5 to 8. The natural moisture content is generally high, rangmg
commonly above 50 percent in commercial deposits. The specific
gravity of opal ranges from 1.8 to .25. However, because of the poros-
ity of the individual diatom shell and the degree of compaction, the
apparent specific gravity of dry unconsolidated diatomaceous earth
ranges from 0.12 to 0.25, and dry consolidated material has a specific
gravity of about 0.4. The porosity of commercial diatomaceous earth
ranges from 75 to 85 percent. The combined water (about 6 percent)
is driven off between 500° and 800°C and the melting point is reached
between 1,400° and 1,600°C; however, earths containing certain impu-
rities may melt well below 1,400°C. Specifications for commercial
diatomite (largely filter use) emphasize particle-size distribution and
species of diatoms (shapes and sizes), as well as density and physical
state, with chemical purity generally a secondary consideration.
History of Development
The commercial value of diatomite was not recognized until the
late 1880's, when a small amount was mined from the deposits at
Lompoc for building stone; in 1889, production records show that
39 tons of diatomite were mined from deposits near Calistoga in
Napa County. During the early 1900's, only a few hundred tons
MINERAL AND WATER RESOURCES OF CALIFORNIA 153
were mined annually in California, but the material was being tested
for several uses, such as heat insulation and refining of beet sugar.
The latter use bacame the foundation of the modern diatomite in-
dustry, and filter application has been a prime consideration in the
evaluation of any diatomaceous earth deposit planned for large scale
exploitation. The Lompoc deposits were being actively developed
at the turn of the century, and, beginning in 1904, the deposits in
Monterey County were developed. At the time of World War I,
California's annual production had reached about 13,000 tons.
The diatomite industry developed rapidly after World War I,
from an important statewide industry to one of national and even
international significance. The Johns-Manville Corp. gained control
of a large part of the Lompoc deposits in 1928, and, in 1930, the
Dicalite Co. opened the extensive deposits in the Palos Verdes Hills
in Los Angeles County. The industry was consolidated by a few
large corporations during the 1940's, and, with the stimulus of World
War II and industrial expansion since then, a steady rise in both
tonnage and average price has been recorded. The Dicalite Co. ac-
quired deposits neai- Lompoc in 1942, and in 1944, the company was
purchased by the Great Lakes Carbon Corp. Mining of diatomite
in Monterey County ceased in 1942 after nearly $500,000 worth of
material had been produced. The Palos Verdes Hills deposits were
alDandoned in 1958, when the Great Lakes Carbon Corp. centered
all of its production at Lompoc. The Lompoc area since has retained
and re-enforced its position as the main world source of diatomite.
Production Factors
For over 50 years, the United States has been pre-eminent among
the countries of the world in the mining and processing of diatomite,
and California yields about 80 percent of the approximately 500,000
tons mined annually in the United States. About one-quarter of this
tonnage is exported to over 60 countries. Exports go mainly to
Europe, but important markets are in the Orient, Australia, and Latin
America. Diatomaceous earth deposits occur throughout the world,
but only the largest, best suited and best situated deposits can compete
in the world market. In recent years this market has expanded and
undeveloped deposits near the European, Asian and Latin American
consuming centers have taken on new significance. Deposits have
been developed or new plants built in France, Mexico, and Yugoslavia,
and some interest has been shown in developing deposits in Iceland.
Established sources in Brazil, Denmark, France, Gennany, Italy, and
elsewhere are all contributing a larger share as well. Most significant
is the development of the Kussian diatomite industry which is esti-
mated to yield nearly 350,000 tons annually, making it second only
to the United States.
The United States is the largest consumer of diatomite, and Cali-
fornia supplies the major part of this market, with the balance coming
from domestic sources, mainly from deposits in Nevada. California
production during the last several years has maintained a steady in-
crease in volume and dollar value to meet the increasing demand
through industrial growth of both the United States and foreign
countries. The value of diatomite production places this commodity
among the most important industrial minerals mined in the State.
67-164 O— 66^pt. I 11
154
MINERAL AND WATER RESOURCES OF CALIFORNIA
The annual value in recent years has equaled, that of the combined
annual values of clay, gold, gypsum, mercury, pumice, and talc. A
significant demand exists for diatomite in the manufacturing and
agricultural industries of California, but the principal markets lie in
central and eastern United States. Although the State possesses
large and varied resources, several thousand tons of mainly filler grade
material is brought annually into California from deposits in adjacent
states.
Occurrences in California
Although diatomaceous strata are accumulating in modem basins,
the principal commercial sources of diatomite are from ancient de-
posits. In California, the oldest marine formation known to contain
. _...
I \ j TRINITY (
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2 . Great Val ley
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Commerci a I depos i ts
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Figure 22. Regional distribution of diatomaceous earth in California.
MINERAL AND WATER RESOURCES OF CALIFORNIA
155
diatomaceous earth is the Moreno Formation of Late Cretaceous and
Paleocene age, and the earliest diatom-bearing lacustrine strata are
those in the upper part (Miocene) of the Cedarville Series, The
thickest and purest commercial deposits known in the State were
formed during late Miocene and early Pliocene times.
At various times since the Cretaceous Period, diatomaceous earth
contributed a significant part of the stratigraphic record in California,
and, although much of the older deposits have been chemically altered
to dense cherty rocks and great volumes of material have been eroded
away, California still possesses widespread resources (table 17), As
shown on figm'e 22, these occur in five geographic regions: Coastal,
Great Valley, Modoc Plateau, Channel Islands, and Desert, and minor
occurrences are sparsely scattered elsewhere (fig, 22) .
Table 17, — Principal formations containing diatomaceous earth in California
Geologic age
Formation i and distribution (shown on fig. 22)
Marine
Region
Lacustrine 2
Region
Recent
Unnamed strata in local basins
eastern Siskiyou County and
western Modoc County.
Unnamed strata in Mono basin.
Long Valley basin (Mono
County) and Owens basin(*)
and Indian Wells Valley basin
(Inyo County).
Unnamed strata in Knight's Ferry
area western Tuolumne County;
may be upper Phocene(*).
Unnamed strata in southwestern
sart of Imperial County; may
be Recent.
Mohawk Lake Beds (may be
Pliocene in part).
Cache Formation (Pliocene or
Pleistocene).
Alturas . .
3
Pleistocene
5
Pliocene
Unnamed strata at Point Reyes
western Marin County.
Unnamed strata in south-central
Monterey County.
Purisima -
1,2,4
2
2
2
2
2
2
3
1
3
Sonoma Volcanics(*)
1
Coso (Pliocene or Pleistocene)
Upper part, Cedarville series
Unnamed strata in Long Valley
area eastern Lassen County
(probably upper Pliocene or
Pleistocene) .
5
Foxen
Miocene
Sisquoc (Miocene and Pliocene)
(").
Monterey (**)
3
Puente
Modelo ..
Maricopa (of former usage)
Salinas (of former usage)
Claremont
Pismo (Miocene and Pliocene)
Round Mountain
Unnamed strata on San Clemente
Island.
Unnamed strata on Santa Cata-
Una Island (*).
Santa Marearita(?) . ...
Reef Ridge
Eocene
Kreyenhagen (Eocene and Oligo-
cene) (*).
Markley (Member of Kreyen-
hagen).
Kellogg
Tertiary
3
Upper Creta-
Moreno
2
ceous.
' Known commercial deposits: major sources (**); minor sources (*). Some formations listed are equiva-
lents of each other, notably the Monterey Formation and its local designations; some formation names
are no longer in use but appear in the Uterature.
2 Numerous diatomaceous earth deposits of the lacustrine type occur throughout the Modoc Plateau
Region (3). These deposits have not been studied and no geologic age or formation assignment has been
made; they probably range in age from Miocene to Recent.
156 MINERAL AND WATER RESOURCES OF CALIFORNIA
Coastal region
The coastal counties, from Lake southward to Orange, form a broad
belt from which nearly all of the diatomite has been produced in Cali-
fornia. The marine Sisquoc and Monterey Formations have yielded
b}^ far the greatest tonnages, with minor production from the lacus-
trine part of the Sonoma Yolcanics. The principal deposits occur
near Lompoc, in Santa Barbara County ; at Bradley and Monterey, in
Monterey County; and on the Palos Verdes Peninsula in Los Angeles
County. Other diatomite deposits occur south of Morro Bay in San
Luis Obispo County; on the north and south slopes of the Santa
Monica Mountains and in the Puente Hills, in Ventura and Los An-
geles Counties ; near Santa Ana and San Juan Capistrano in Orange
County ; and in southern Napa and Sonoma Comities.
The Lompoc deposits are believed to be the largest source of diato-
mite currently being exploited in the world. The diatomite occurs as
gently folded strata in isolated patches in the northern hills of the
western Santa Ynez Mountains south of Lompoc, and in the Purisima,
Casmalia, and Solomon Hills, north of Lompoc. In these areas the
diatomaceous earth is in the upper part of the Monterey Formation
and lower part of the Sisquoc Formation, and is many hundreds of feet
thick. However, most of this contains too much clay and other im-
purities for industrial use. Only certain selected strata a few feet or
few tens of feet thick that meet commercial specifications are quarried
for industrial use. The aggregate thickness of the commercial diato-
mite may be several hundred feet.
The two principal companies operating in this area, the Johns-
Manville Products Corp., which with its predecessors pioneered the
development of the Lompoc deposits, and the Dicalite Division of
Great Lakes Carbon Corp., mine from several extensive quarries in the
hills south of Lompoc. On the north side of the Lompoc Valley, Dia-
tomic Chemical Co. mines and processes diatomite, mainly for absorb-
ents. North of the Lompoc Valley, in the Casmalia Hills bituminous
diatomaceous shale is mined for lightweight aggregate and pozzolan
by the Airox Co. This material is calcined by simple burning, utiliz-
ing the natural oil in the rock as a fuel. Numerous other deposits of
possible commercial grade occur in the Lompoc area but these have
been mined only intermittently. The Basalt Rock Co., Inc. in recent
years has mined diatomite from the Sonoma Volcanics of Pliocene
age in southern Napa Comity.
Great Valley region
Thick sequences of diatomaceous earth, that range in age from Late
Cretaceous through late Miocene occur along the western edge of the
San Joaquin Valley, from the ]Mount Diablo area in Contra Costa
County southeastward into Kern County. The main deposits are in
the Moreno Formation of Late Cretaceous and Paleocene age,
Kreyenhagen Formation of Eocene and Oligocene age and the prob-
able northern extensions of the Kreyenhagen, the Markley Member.
Other sources several hundred feet thick are in the Monterey and Reef
Ridge Formations of Miocene age. These diatomaceous strata com-
monly extend for several miles along the west margin of the valley and
dip gently to steeply east. Locally, the material is light colored and
MINERAL AND WATER RESOURCES OF CALIFORNIA 157
nearly pure, but, for the most part, is pale tan to brown and consid-
erably contaminated with clay. Exploitation of these sources has
been attempted at various times, but no sustained oi>erations have
developed nor has any signiticant volume of material been mined.
Across the valley in the vicinity of Knight's Ferry in southwestern
Tuolumne County, occurs a relatively pure, nearly white deposit of
diatomite of lacustrine origin, of Pliocene or Pleistocene age. The
diatomite layer is at least 15 feet thick. The Pacific Clay Products
Co. has mined several thousand tons from this deposit in recent years.
Modoc Pl-ateau
Numerous deposits of diatomac^ous earth are scattered throughout
the volcanic terrane of northeastern California. These were formed
during part of the long volcamc history of this region, which began
in early Tertiary time and has continued to the Recent. Contrary to
general belief, the deposits in this region are not all capped by volcanic
flows ; most of them are exposed at the surface or lie below a thin sedi-
mentary cover; only some of the better known deposits are intercalated
with flows. The diatomaceous earth beds range from a few feet to
a few hundred feet thick, and some deposits occur over tens of square
miles. The material commonly is brilliant white and relatively pure,
but many deposits are considerably contaminated with volcanic ash.
The evolution of the diatom flora in the various lake basins of this
region bears on the nature of the deposits and on the possible commer-
cial suitability of the material. The earliest known deposits are of
Miocene age and are comprised commonly of only one species of
diatom, Melosira gromalata. This is a thick-walled form that is not
suitable for filter or many other uses. Subsequently, however, vari-
ous species of diatoms invaded local basins in this region, and the
corresponding deposits comprise a more diverse flora. The early
Pliocene and Pleistocene deposits may have many tens of species rep-
resented, and this material is better suited for many industrial
applications.
Some of the better known deposits are near Alturas, in Modoc Coun-
ty ; along Willow Creek near Dorris, in Siskiyou County ; around the
shores of Lake Britton, and along Hat Creek in Shasta County. Nu-
merous other localities are known, and many more probable occurrences
are suggested by geologic maps. The Modoc Plateau region offers the
best place for locating new sources of diatomite in California.
Channel Islands region
The rocks of the eight Channel Islands are for the most part similar
to those of the adjacent coastal area, and diatomaceous earth is known
to occur on Santa Catalina, San Clemente, Santa Cruz, and Santa Rosa
Islands. Marine(?) diatomaceous earth occurs with upper Miocene
andesite east of Isthmus Cove on Santa Catalina Island; unnamed
marine strata of middle Miocene age, in part diatomaceous earth, occur
south of Wilson Cove and at other places on San Clemente Island;
diatomaceous shales of the Monterey Formation are exposed on Santa
Rosa and Santa Cruz Islands. Minor production has been recorded
from the deposit on Santa Catalina Island.
Desert region
In the eastern desert of California diatomaceous earth was deposited
in lakes along an integrated drainage system during Pleistocene time,
158 MINERAL AND WATER RESOURCES OF CALIFORNIA
and in a similar but less known system during Pliocene time. The
diatomaceous earth layers in this region are generally less than 10
feet thick; the material is off-white in color, and nearly all of the
deposits are contaminated with volcanic ash. Diatomaceous earth is
known to occur in several of the Pleistocene basins, of which the prin-
cipal sources are in Long Valley, Mono County ; Owens Valley, from
which minor production has been recorded ; and Indian Wells Valley,
Inyo County. Diatomaceous earth of Pliocene age is intercalated
with lacustrine rocks in the Coso Range, Inyo County.
Acknowled gmcnt . — Dr. Paul W. Leppla and Earnest L. Neu of the Great Lakes
Carbon Corp. kindly provided information and reviewed the manuscript.
Selected References
Bramlett, M. N., 1946, The Monterey Formation of California and the origin of
its siliceous rocks: U.S. Geol. Survey Prof. Paper 212, 57 p.
Burnett, J. L., and Jennings, C. W., 1962, Geologic map of California, Chico
sheet : California Div. Mines and Geology, scale 1 : 250,000.
Calvert, S. E., 1964, The accumulation of diatomaceous silica in the sediments of
the Gulf of California [abs.] : Los Angeles, Soc. Econ. Paleontologists and
Mineralogists Ann. Mtg.
Cleveland, G. B., 1958, Poverty Hills diatomaceous earth deposit, Inyo County.
California : California Jour. Mines and Geology, v. 54, no. 3, p. 305-316.
, 1961, Economic geology of the Long Valley diatomaceous earth deposit.
Mono County, California : California Div. ]Mines and Geology, map sheet 1.
Dibblee, T. W., Jr.. 1950, Geology of southwestern Santa Barbara County, Cali-
fornia— Point Arguello, Lomix)C, Point Conception, Los Olivos, and Gaviota
quadrangles : California Div. Mines Bull. 150, 95 p.
Gay, T. E., and Aune, Q. A., 1958, Geologic map of California, Alturas sheet ;
California Div. Mines, scale 1 : 250,000.
Hanna, G. D., 1927, Cretaceous diatoms from California : California Acad.
Sci., Occ. Papers 13, 48 p.
Hart, E. W., 19 , Diatomite, in Mines and mineral resources of Monterey County :
California Div. Mines and Geology County Rept. (in press).
Lohman, K. E., 1960, The ubiquitous diatom — A brief survey of the present
state of knowledge: Am. Jour. Sci., v. 258-A (Bradley Volume), p. 180^191.
Lydon, P. A., Gay, T. E., and Jennings, C. W., 1960, Geologic map of California,
Westwood sheet : California Div. Mines, scale 1 : 250,000.
Oakeshott, G. B., 1957, Diatomite, in Mineral commodities of California :
California Div. Mines Bull. 176, p. 183-193.
Olmsted, F. H., 1958, Geologic reconnaissance of San Clemente Island, Califor-
nia : U.S. Geol. Survey Bull. 1071-B, 68 p.
Schoellhamer, J. E., and Kinney, D. M., 1953, Geology of a part of Tumey and
Panoche Hills, Fresno County, California : U.S. Geol. Survey Oil and Gas
Inv. Map OM-128.
Woodring, W. P., and Bramlette, M. N., 1950, Geology and paleontology of the
Santa Maria district, California : U.S. Geol. Survey Prof. Paper 222, 185 i\
Woodring, W. P. Bramlette, M. N., and Kew, W. S. W., ]946, Geology and paleon-
tology of Palos Verdes Hills, California : U.S. Geol. Survey Prof. Paper 207.
145 p.
FELDSPAR
(By F. G. Lesure, U.S. Geological Survey, Washington, D.C.)
Feldspar has been produced in California nearly continuously since
prospecting was first reported in 11)09 in Monterey and San Diego
Counties. More than 70 deposits in 11 counties have been mined or
prospected, but production from most of these has been small. Total
production from 1910 through 1963 is probably greater than 600,000
MINERAL AND WATER RESOURCES OF CALIFORNIA 159
long tons of feldspar worth a little more than $4,000,000. From 1909
to 1951 most of the production came from coarse-grained feldspathic
pegmatites and amounted to nearly 170,000 tons. Yearly production
ranged from less than 1,000 tons in 1910 and 1911 to nearly 15,000 tons
in 1928 (Sampson and Tucker, 1931, p. 407; U.S. Bureau of Mines
Minerals Yearbooks). In 1952 the Del Monte Properties Co. began
recovering feldspar by flotation methods from beach sand in Monterey
County. Soon after this the Owens-Illinois Glass Co. also began pro-
ducing feldspar from an adjacent deposit. Because of this increased
production from beach sands California has ranked second after North
Carolina in feldspar production since 1957.
MnSTERALOGY
Feldspar is the general name for a group of aluminum silicate min-
erals that contain varying amounts of potassimn, sodium, or calcium.
The feldspars are important rock-fonning minerals and constitute
nearly 60 percent of many igneous rocks. The principal potassium
feldspare are orthoclase and microcline which have the same chemical
composition (KAISisOs) but different cryst^al form. The sodiimi-
calcium feldspars, called plagioclase, form a complete series of min-
erals that range in all proportions from pure NaAlSiaOg (albite) to
pure CaALSiaOs (anorthite) . Natural orthoclase and microcline gen-
erally contain 10 to 24 percent NaAlSiaOg and plagioclase generally
contains 5 to 15 percent KAlSisOs- Intergrowths of orthoclase or
microcline with albite are called perthite, a common pegmatite min-
eral. The potassium feldspars and the more soda-rich forms of plagio-
clase are the types generally mined, but calcium-rich feldspar has been
mined from anorthosite bodies in Los Angeles County (Gay and
Hoffman, 1954, p. 666).
Geologic Occtjrrence
Commercial deposits of feldspar are found in pegmatites, granites
and related igneous rocks, and beach sands.
Pegmatites are generally light-colored coarsely crystalline igneous
rocks, found as lenticular or tabular bodies in metamorphic rocks or
associated with large granitic intrusions. Individual mineral grains
range in length from an inch or less to many feet. Feldspar, quartz,
and mica are the most common minerals present, but many rare and
unusual minerals are found in some deposits. In many pegmatites
the minerals are more or less evenly distributed throughout, but in
others the minerals are segregated into certain layers or parts of the
body called zones. In some pegmatites these zones can be selectively
mined to recover the desired minerals by hand sorting and are, there-
fore, important economically. Until recently most of the feldspar pro-
duced in the United States was perthite which is commonly concen-
trated as very large crystals in certain zones in pegmatite bodies.
Granite and related igneous rocks are composed of one or two kinds
of alkalic feldspar and quartz and minor amounts of various other
minerals, mainly muscovite, biotite, hornblende, or rarely pyroxene.
Deposits range from small masses measured in feet to very large masses
measured in miles. Grain size ranges from less than one-fourth inch
160 MINERAL AND WATER RESOURCES OF CALIFORNIA
to an inch or more. Today, deposits of granite that contain only small
amounts of ferro-magnesian minerals are mined in bulk and a mixture
of potassium and sodnnn feldspar is recovered by milling and flotation.
Beach sands and alluvial deposits rich in feldspar are composed of
loose sand grains generally less than one-fourth inch in diameter.
Few deposits are rich enough to be worked and only the deposits of
Pacific Grove, Monterey County, California, have been worked
extensively.
In 1963 about 57 percent of the feldspar used in the United States
was from flotation concentrates, IT percent was from hand sorting, and
16 percent was from feldspar-ricli sand (Cooper, 1964, p. 496). In
1957 these figures were 42, 46, and 12 percent, respectively.
Economics and Uses
The average price of crude feldspar was $10.06 per long ton in
1963 and $9.51 in 1960 (Cooi^er, 1964, p. 495). The average price of
ground feldspar was $12.28 per short ton in 1963 and $13.40 in 1960.
From 1956 to 1963 about 55 percent of the feldspar sold in the United
States was used in glass, 30 percent in pottery, 5 percent in enamel,
and 10 percent in other ceramic uses, scouring soaps, and abrasives.
Feldspar is used in glass and ceramics as a flux and to impart strength,
toughness, and durability to the end product (Castle and Gillson, 1960,
p. 360) . The glass industry buys feldspar or one of its substitutes as
total units of alumina (AI2O3) plus potash (K2O) plus soda (NaaO).
The iron content must be no more than 0.05 percent FcsOa for most
glass grade feldspar, but amber glass may contain up to 0.50 percent.
Potassium feldspar is generally preferred in the ceramic industry.
The United States is self -sufficient in feldspar production capacity.
There is an mcreasing shortage of high-grade potassium feldspar but
there is an mcrease in use of lower grade and finer grained materials
through milling and flotation. For the past 70 yeai^ the United States
has been the leading producer and user of feldspar; production in
the last few years has averaged 520,000 long tons a year or about one-
third world production (Wells, 1965). The largest production comes
from North Carolina, California, and Comiecticut. Other important
producing states include Colorado, Georgia, Maine, New Hampshire,
South Dakota, and Virginia. Much of the high-grade potassium
feldspar used in California has come from Kingman, Arizona.
In recent years various materials have been used in the glass and
ceramic industries as substitutes for feldspar. Chief among these are
nepheline syenite, aplite, talc, pyrophyllite, and blast furnace slag (de
Polo, 1960, p. 286). Most nepheline syenites contain too much iron
oxide for use in glass, but a deposit in Ontario, Canada, that is low
in iron is mined extensively. Talc has largely replaced feldspar in
wall tile manufacture in California (Wright, 1957, p. 199) .
Occurrences in California
Pegmatites containmg deposits of feldspar are widely distributed
m the southern part of California (Jahns, 1954, p. 42) but only the
famous gem-bearing pegmatites of San Diego County have been
MINERAL AND WATER RESOURCES OF CALIFORNIA 161
studied in detail (Jahns and Wright, 1951; Hanley, 1951). Feldspar
deposits are particularly abundant in the Peninsular Range provmce,
parts of the southern Sierra Nevada, and the Transverse Ranges as
shown on fig. 23 and listed in table 18.
More scattered occurrences are also found in the Great Basin and
Mojave Desert provinces. Larger masses of fuier grained, feldspar-
rich igneous rock which might be sources of flotation feldspar are
present but have not been prospected.
The known deposits or occurrences are listed in table 18 (p. 163).
Most of these are described briefly by Sampson and Tucker ( 1931) , and
the larger deposits are described in more detail by Wright (1957) and
Weber (1963, p. 72-82) . The largest production in the past few years
has come from the dune sands of Pacific Grove, Monterey County, in
an area about 6 miles long and 1 mile wide. The sands are composed of
53 percent quartz, 46 percent feldspar, and less than 1 percent other
minerals. The largest pegmatite deposit is the Pacific mine, San
Diego County, which produced 87,000 tons of feldspar from 1921 to
1943. The only pegmatite deposit worked extensively in recent years,
however, is the White Butte deposit of San Bernardino County,
mined by Gladding McBean and Co., 1940-1960.
Another type of feldspar occurrence that might become important
has been recently described by Sheppard and Gude (1965), who have
found that potash feldspar is the major constituent in a fine-grained
friable tuff, 1.5 to 4 feet thick, in the Barstow Formation of Miocene
age in the central part of the Mud Hills, 10 miles north of Barstow,
San Bernardino County. The tuff underlies an area about 1.5 miles
long and 14 ^^^il^ wide. The material is composed of 87 to 94 percent
potash feldspar, a few percent analcime and quartz, and trace amounts
of other minerals. Iron content ranges from 0.1 to 1.76 percent Fe203.
Although no tests have yet been made, the material may be a potential
source of potash feldspar for ceramics and glass.
Future Outlook
An increasing market for feldspar in California will develop with
the continued growth of local glass and pottery industries. The State
has abundant resources of feldspar in zoned pegmatites, feldspar-
rich granitic rocks, and beach sands, but the feldspar-rich sands of
the Pacific Grove area are the principal reserves at this time. The
chief merit of zoned pegmatites lies in the benefits of selective small-
scale mining confined to a single zone to take full advantage of the
enrichment of that zone. Small capital investments by individuals
or partnerships are required to enter pegmatite mining. Although
most operations are for one mineral, such as feldspar, it is possible to
obtain several products, that is, feldspar, quartz, and mica. Recent
studies have increased the general knowledge of the occurrence, origin,
and economic importance of pegmatite deposits (Cameron and others,
1949; Jahns, 1955), and studies made during World War II have
helped improve techniques of prospecting and exploration (Norton
and Page, 1956). Renewal of pegmatite mining is hindered by the
low cost of the commodity, the smallness of most known deposits, and
the lack of custom mills where small operators can sell crude ore
162
MINERAL AND WATER RESOURCES OP CALIFORNIA
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" ! IIIQ ^— \ Bt»krn.tiftl(t
^LUIS ^\
I ^V"- o,:v\
via __/ -«-
35"
^'Z' OBISPO
^ >JC\SANTA
(KERN
^^.J
rs '^^
\
'J 18 19
I O^J A V E
■-^.5°
\
21 .^{^U-JAV^ ^-^35°
, , r ^— ,'nv'' SAN BERNARDINO "26 ••
^BARBARA I ■■1>,,_\^S ANOEU-'.S' ^ V
X
23
117°
.^%UG.H<^
Figuke23. Feldspar in California (numbers refer to table 18)
(Wright 1957, p. 199). Recovery of feldspar from granitic rocks is
not feasible in California -as long as feldspar-rich sands like those at
Pacific Grove are available. The recent discovery of potash feldspar
in tuff warrants further investigation.
MINERAL AND WATER RESOURCES OF CALIFORNIA
Table 18. — Reported feldspar deposits in California
163
Index
No. on
fig. 23
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
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
Deposits
Reference
Hamilton
Nebicite, Sierra White -
Childers.
Unnamed occurrence
Harrison Stock Farm
Bardin... ..1
Jens, Johnson Bros
Pacific Grove
Britton Ranch
Carter, Goodale
Honora Realty Co., Yokohl Valley
White King -
Nine Mile Canyon -
Pegmatite occurrences..
Rosamond
U nnamed occurrence
White Butte _
Unnamed occurrences '_
Sloan
Unnamed occurrences
Clement and Blackburn
McKnight Cornishstone
Unnamed occurrence _
White Rock.__ _....._
Silica Mining & Products
Cal ipro ducts , Duncan _
Gordon.
Chicago-Pacific, Gates Chemical Co.,
Lambert's Poultry Grits, Stanley Alu-
mina Silicate, Vail.
Keystone and Lucky Jim
Stone
Albert Ranch, Brown Ranch, La Borde,
Morgan Ranch, Patterson Ranch, River-
side Portland Cement, TuUy, Weir Ranch
Ensley-Spaulding, K. and K. Ranch,
Machado.
Perris Mining Co
Murrieta
Last Chance
Littlejohn
Lang
Coahuila Brave
Pala district. Spar King
Lookout, Pearson
Carlsbad
Rincon district
Bear, Langer
Mesa Grande district. Powers group.
Black Canyon
Mykrantz
Hoover, McGinty Mountain
Spanish Bayonet
Laguna Junction, White Rose
Toms Dream
Buckthorn, Crestline, Gem Spar, Elder
Pacific mine
Pilz
Quality
Marden, Walker, Ward and Williams,
White Butte.
Dos Cabezas, Moore, Overlook
EUiot, Red Desert
Superstition Mountains
Cargo Muchacho Mountains
Sampson and Tucker, 1931, pp. 419-420.
Norman and Stewart, 1951, pp. 99-100.
Logan and others, 1951, p. 502.
Do.
Sampson and Tucker, 1931, p. 415.
Sampson and Tucker, 1931, p. 420.
Wright, 1957, p. 197; Sampson and Tucker, 1931,
p. 420.
Messner, 1954, pp. 5-8.
Sampson and Tucker, 1931, p. 432.
Do.
Do.
Tucker and Sampson, 1938, p. 483.
Wright, 1957, p. 197.
Dibblee and Chesterman, 1953, p. 32.
Troxel and Morton, 1962, p. 266.
Spurck, 1964, p. 75.
Wright and others, 1953, p. 165; Wright, 1957, p. 197.
Oesterling and Spurck, 1964, p. 172.
Sampson and Tucker, 1931, p. 426.
Spurck, 1964, p. 75.
Sampson and Tucker, 1931, p. 426.
Wright and others, 1953, p. 144.
Oesterling and Spurck, 1964, p. 172.
Sampson and Tucker, 1931, p. 445.
Gay and Hoffman, 1954, p. 666.
Gay and Hoflman, 1954, pp. 525, 665.
Gay and Hoffman, 1954, p. 665.
Gay and Hoffman, 1954, pp. 525, 665-666.
Sampson and Tucker, 1931, p. 426.
Sampson and Tucker, 131, p. 425.
Sampson and Tucker, 1931, pp. 420-426.
Sampson and Tucker, 1931, pp. 422-424.
Sampson and Tucker, 1931, pp. 424-425.
Sampson and Tucker, 1931, p. 421.
Sampson and Tucker, 1931, p. 423.
Do.
Do.
Sampson and Tucker, 1931, p. 422.
Jahns and Wright, 1951, p. 51; Tucker and Reed,
1939 p. 37
Tucker and Reed, 1931, pp. 31, 37.
Weber, 1963, p. 79.
Hanley, 1951.
Weber, 1963, pp. 79, 81.
Weber, 1963, pp. 82-87.
Weber, 1963, p. 79.
Sampson and Tucker, 1931, p. 430.
Weber, 1963, pp. 75, 80.
Everhart, 1951, p. 114.
Weber, 1953, p. 80; Sampson and Tucker, 1931, p.
431.
Weber, 1963, p. 83.
Weber, 1963, p. 79; Wright, 1957, p. 197.
Wright, 1957, pp. 196-198; Weber, 1963, pp. 76-78.
Sampson and Tucker, 1931, p. 431.
Weber, 1963, p. 84.
Weber, 1963, pp. 81, 83, 217.
Sampson and Tucker, 1931, pp. 428-430; Tucker and
Reed, 1939, p. 11.
Weber, 1963, p. 80; Sampson and Tucker, 1942,
pl.l.
Sampson and Tucker, 1942, p. 134.
Henshaw, 1942, p. 159.
164 MINERAL AND WATER RESOURCES OF CALIFORNIA
Seleoteid References
Cameron, E. N., Jahns, R. H., McNair, A. H., and Page, L. R., 1949, Internal
structure of granitic pegmatites : Econ. Geology Mon. 2, 115 p.
Castle, J. E., and Gillson, J. L., 1960, Feldspar, nepheline syenite, and aplite, in
Industrial minerals and rocks, 3d ed. : Am. Inst. Mining Metall. and Petroleum
Engineers, New York, p. 339-362.
Cooper, J. D., 1964, Feldspar, nepheline syenite, and aplite: U.S. Bur. Mines
Minerals Yearbook 1962, v. 1, p. 495-503.
de Polo, Taber, 1960, Feldspar, in Mineral facts and problems : U.S. Bur. Mines
Bull. 585, p. 283-289.
Dibblee, T. W., Jr., and Chesterman, C. W., 1953, Geology of the Breckenridge
Mountain quadrangle, California : California Div. Mines Bull. 168, 56 p.
Everhart, D. L., 1951, Geology of the Cuyamaca Peak quadrangle, San Diego
County, California, in Oi"ystalline rocks of southwestern California : California
Div. Mines Bull. 159, p. 51-115.
Gay, T. E., Jr., and Hoffman, S. R., 1954, Mines and mineral deposits of Los
Angeles County, California : California Jour. Mines and Geology, v. 50, nos.
3-4, p. 467-709.
Hanley, J. B., 1951, Economic geology of the Rincon pegmatites, San Diego
County, California : California Div. Mines Spec. Rept. 7-B, 24 p.
Henshaw, P. C, 1942, Geology and mineral deposits of the Cargo Muchacho
Moimtains, Imperial County, California : California Jour. Mines and Geology,
V. 38, no. 2, p. 147-196.
Jahns, R. H., 1954, Pegmatites of southern California, [Pt.] 5 in Chap. 7 of Jahns,
R. H., ed.. Geology of southern California : California Div. Mines Bull. 170,
p. 37-50.
, 1955, The study of pegmatites, in Pt. 2 of Bateman, A. M., ed., Econ.
Geology 50th Ann. Volume, pt. 2, p. 1,025-1,130.
Jahns, R. H., and Wright, L. A., 1951, Gem- and lithium-bearing pegmatites of
the Pala district, San Diego County, California : California Div. Mines Spec.
Rept. 7-A, 72 p.
Logan, C. A., Braun, L. T., and Vernon, J. W., 1951, Mines and mineral resources
of Fresno County, California : California Jour. Mines and Geology, v. 47, no. 3,
p. 485-552.
Messner, W. E., 1954, Flotation of Del Monte sand: California Div. Mines,
Mineral Inf. Service, v. 7, no. 7, p. 5-8.
Norman, L. A., Jr., and Stewart, R. M., 1951, Mines and mineral resources of
Inyo County : California Jour. Mines and Geology, v. 47, no. 1, p. 17-223.
Norton, J. J., and Page, L. R., 1956, Methods used to determine grade and
reserves of pegmatites : Mining Eng., v. 8, no. 4, p. 401-414.
Oesterling, W. A., and Spurck, W. H., 1964, Eastern Mojave and Colorado Deserts,
in Southern Pacific Company, Minerals for industry, southern California, Sum-
mary of Geological Survey of 1955-1961, v. 3, San Francisco, p. 99-242.
Sampson, R. J., and Tucker, W.B., 1931, Feldspar, silica, andalusite and kyanite
deposits of California; California Jour. Mines and Geology, v. 27, no. 3, p.
407-464.
Sheppard, R. A., and Gude, A. J., 3d., 1965, Potash feldspar of possible economic
value in the Barstow Formation, San Bernardino County, California : U.S.
Geol. Survey Circ. 500, 7 p.
Spurck, W. H., 1964 Western Mojave Desert, in Southern Pacific Company, Mm-
erals for industry, southern California, Summary of Geological Survey of
1955-1961, V. 3, San Francisco, p. 37-97.
Troxel, B. W., and Morton, P. K., 1962, Mines and mineral resources of Kern
County, California : California Div. Mines and Geology County Rept. 1, 370 p.
Tucker, W. B., and Reed, C. H., 1939, Mineral resources of San Diego County,
California : California Jour. Mines and Geology, v. 35, no. 1, p. 8-55.
Tucker, W. B., and Sampson, R. J., 1938, Mineral resources of Inyo County:
California Jour. Mines and Geology, v. 34, no. 4, p. 368-500.
Weber, F. H., Jr., 1963, Geology and mineral resources of San Diego County,
California : California Div. Mines and Geology County Rept. 3, 309 p.
Wells, J. R., 1965, Feldspar, in Mineral facts and problems, 1965 ed. : U.S. Bur.
Mines Bull. 630, preprint, 7 p.
Wright, L. A., 1957, Feldspar, in Wright, L.A., ed.. Mineral commodities of Cali-
fornia : California Div. Mines Bull. 176, p. 195-200.
Wright, L. A., Stewart, R. M., Gay, T. E., Jr., and Hazenbush, G. C, 1953, Mines
and mineral deposits of San Bernardino County, California : California Jour.
Mines and Geology, v. 49, nos. 1-2, p. 49-260.
MINERAL AND WATER RESOURCES OF CALIFORNIA 165
FLUORSPAR
(By C. W. Chesterman, California Division of Mines and Geology,
San Francisco, Calif.)
Fluorspar is a term applied to a mineral aggregate which is com-
posed principally of fiuorite and which contains sufficient fluorine to
be useful in the chemical, metallurgical, and ceramic industries.
Fiuorite (CaFg) is the only fluorine-bearing mineral of economic
importance. When pure, it contains 48,7 percent fluorine and 51.3
percent calcium. Fiuorite has a hardness of 4 on the Mohs' scale,
compared with 3 for calcite and 7 for quartz, and a specific gravity of
3.00 to 3.25. It has three perfect cleavages and occurs in many colors
ranging through dark purple, blue and yellow to white and colorless.
On the basis of these physical properties, fiuorite can readily be dis-
tinguished from calcite and quartz with which it is commonly asso-
ciated.
The principal use of fluorspar is in the production of hydrofluoric
acid. An exceedingly pure grade of finely ground (80 to 100 mesh)
fluorspar, normally containing a minimum of 97 percent CaF2, is com-
bined with sulfuric acid to form hydrofluoric acid. Hydrofluoric acid
is used in the production of plastics, fungicides and pesticides, refriger-
ants, high octane gasoline, and in the manufacture of artificial cryolite
and aluminum fiuoride which are used in the production of aluminum.
The metallurgical use of fluorspar in steel production, once the most
important, is now second in importance. Metallurgical-grade fluor-
spar should contain at least 85 percent CaF2, and materials analyzing
below that value are subject to penalties.
Third in consumption of fluorspar is the ceramic industry, which
uses finely ground fluorspar in the manufacture of opalescent, opaque
and colored glasses, earthenware glazes, and opacified enamels. Ce-
ramic-grade fluorspar must contain at least 85 percent CaFg, less than
4 percent SiOs, and less than 0.14 percent FejOa.
Most fluorspar of commercial interest occurs in veins and irregular
bodies enclosed in sedimentary, metamorphic, or igneous rocks. They
are replacement deposits and cavity fillings, and have a fiuorite con-
tent generally ranging from 50 to 95 percent. Fiuorite also occurs
as a gangue mineral associated with copper, lead and silver ores.
Agricola (1546, p. 109) was the first to use the name fiuorite because
the mineral became fluid when heated to high temperatures. The
fact that fiuorite has low viscosity and the ability to form eutectics
when in the molten state led to an early use of the mineral in many
metallurgical processes, especially in steel manufacture.
The United States production of fluorspar in 1963 was 586,000
short tons, approximately 80 percent of the domestic consumption.
Production of fluorspar in the United States has decreased in recent
years due to competition of foreign imports, especially those from
Mexico, and has resulted in the closing down of many domestic mines.
Production of fluorspar in California to date has been less than 1,000
short tons, and is unable to keep pace with the demands of industry.
There are many occurrences of fluorspar in California, but those
deposits from which small quantities have been produced are in Inyo,
Riverside, and San Bernardino Counties (fig. 24).
166
MINERAL AND WATER RESOURCES OF CALIFORNIA
EX PLANA! ION
1. Warm Spring Canyon
2 . Pa 1 en Mount a ins
3. Little Maria Mountains
4 . Cave Canyon
'v 5. Orocopia Mountains
1 N Y O XS \
117-
11'^°
Figure 24. Fluorspar in California.
At a deposit en the north slope of Warm Springs Canyon,- Panamint
Range, Inyo County, fluorspar occurs in veins from 1 foot to 10 feet
thick that cut Precambrian granite gneiss (Crosby and Hoffman,
1951, p. 632) The CaFo content of representative samples ranges from
29 to 65 percent. A small quantity of fluorspar was produced from
one of the veins; the property has been idle since the 1940's. The
Palen Momitains, eastern Riverside Comity, contain many veins
of fluorspar. At one locality near the north end of this range, a
fluorspar-bearing vein, 5 feet in thickness occurs in monzonite. The
vein consists of green, white, and purple fluorite in a matrix of mala-
chite, azurite, calcite, and quartz. A deposit on the east slope of the
MINERAL AND WATER RESOURCES OF CALIFORNIA 167
Little Maria Mountains, about 14 miles south of Rice, Riverside
County, contains several fluorspar-bearing veins from 18 inches to 3
feet in thickness, and as much as 40 feet in length. These veins occur
in quartzite and schist. An analysis representative of 130 tons which
was shipped from the deposit in 1944, showed 87 percent CaFz, 4 per-
cent Si02, 0.47 percent CaO, 2.25 percent AI2O3, and 0.15 percent
Fe^Oa.
The largest number of known fluorspar deposits in California is
in San Bernardino County, but only one area has been p)roductive.
In the Cave Canyon district near Afton, fluorspar is associated with
fine-grained andesitic rocks which occur as intrusive bodies and flows.
The volcanic rocks are fractured and form breccias which, in places,
contain much coarse crystalline fluorspar. The fluorspar-bearing
zones of brecciated andesite are irregular and range from 1 foot to
50 feet in thickness. They are traceable for nearly 2,000 feet on the
surface. Some fluorspar occurs in veins that range from a few inches
to 4 feet in thickness. The richer parts of the fluorspar-bearing zones
locally contain 10 to 40 percent fluorite, but such concentrations are
small. Both silica and calcite are present, but metallic sulfides are
lacking. Analysis of representative samples shows a range of 35 to
86 percent CaFa, 8 to 44 percent SiOg, and 2 to 29 percent CaCOs
( Burchard, 1933, p. 373-374 ) .
In 1955, fluorspar was discovered in the Orocopia Mountains, a
few miles south of Shaver Summit, eastern Riverside Coimty. Here,
several veins of fluorspar, ranging from a few inches to six feet in
width, occur in shear and breccia zones in coarse-grained Mesozoic
quartz monzonite. The veins are parallel and pinch and swell along
their strike. The largest vein has been prospected intermittently
along a strike length of 500 feet. Mine-run fluorspar contains over
91 percent CaFg , and a hand-picked sample was found to contain
97.83 percent CaF,. The fluorspar meets all specifications for metal-
lurgical uses, and a small shipment was made early in the spring of
1955 to the Kaiser Co. at Fontana, California, for use in steel manu-
facture. The prospect has been inactive since 1956.
The potential for a substantial fluorspar production in California
is certainly not indicated by its total production in the State. Al-
though there are numerous occurrences of fluorspar in California,
they appear to be in small deposits of several thousand tons or less.
However, the potential for new discoveries is good, especially in areas
where there has been limited production and where prospecting and
exploitation have been on a limited basis only.
The copper- and fluorite-bearing siliceous veins in the carbonate
rocks of the Tin Mountain area, Inyo County, the fluorite veins in the
granitic and metamorphic rocks of the Orocopia and Palen Mountains,
Riverside County, and the fluorite-sericite replacement veins in the
Goodsprings (Cambrian to Devonian?) Dolomite in Clark Mountain,
San Bernardino County, are worthy of further prospecting and ex-
ploitation.
Selected References
Agricola. Georg, 1546, De Natura Fossilium : Translated from First Latin Edi-
tion of 1546 by M. C. and J. A. Bandy : Geol. Soc. America Spec. Paper 63, 1955.
Burchard, E. F., 1933, Fluorspar deposits in western United States: Am. Inst.
Mining Metall. Engineers Trans., v. 109, p. 373-374 and 395.
168 MINERAL AND WATER RESOURCES OF CALIFORNIA
Chesterman, C. W., 1957, Fluorspar in mineral commodities of California : Cali-
fornia Div. Mines Bull. 176, p. 201-204.
Crosby, J. W., and Hoffman, S. R., 1951, Fluorspar in California : California
Jour. Mines and Geology, v. 47, no. 4, p. 619-638.
McAllister, J. F., 1952, Rocks and structure of the Quartz Spring area, northern
Panamint Range, California : California Div. Mines Spec. Rept. 25, p. 36.
GARNET
(By D. M. Lemmon, U.S. Geological Survey, Menlo Park, Calif.)
Garnet constitutes a mineral group of six main gradational species
that are closely related, having the same isometric crystal habit and
the same general formula but composed of different combinations of
the silicates of magnesium, aluminum, iron, calcium, manganese,
chromium, and rarely titanium. They are hard (range from 6.5 to
7.5), tough, moderately heavy (sp. gr. 3.5 to 4.2), and without cleav-
age but with a sharp fracture.
The principal commercial use is in coated abrasives, formed by
cementing closely sized grains to paper or cloth. Garnet-coated papers
and cloth are used primarily in woodworking but also in finishing
leather, hard rubber, plastics, felt, and the softer metals. Garnet is
used extensively in finely sized loose grains to grind glass and lenses ;
a sludge of 25 micron garnet and water was used in an intermediate
finishing operation in grinding the main mirror of the 120- inch tele-
scope at Lick Observatory, Mount Hamilton, Calif. (Hill, 1959).
Garnet is also used in sizes between 17 and 45 mesh for sandblasting
because it is tougher and heavier than the commonly used silica sand,
making it a more efficient impact abrasive, and it can be reused.
Garnet is found in many geologic environments and is geographi-
cally widespread. Two species are of principal commercial use: (1)
almandite, Fe3Al2( 8104)3, which occurs in schists and gneisses, and
(2) andradite, CasFeo (8104)3, found in contact metamorphosed lime-
stone altered to skarn (tactite), in schist, in serpentine, and in some
igneous rocks. The chemical compositions given are for pure end
members, seldom found, for most natural garnets are mixtures and
are named on the basis of the dominant type.
Since World War II, ganiet output in the United 8tates has ranged
from 6,578 short tons in 1949 to 14,626 tons in 1963, valued at $1,412,-
000. The principal production in 1963, as in many years past, was
almandite pyrope (Levm, 1960) from a small area in the Adirondack
Mountains of New York. The remainder of the output came from
alluvial deposits in Idaho and was used principally for sandblasting
(Ambrose, 1964) .
The relatively small United States demand for garnet concentrates
is amply met by these two states. New York also exports to foreign
markets ; its product is superior in the world market as well as in the
United States ( Vogel, 1960) .
Garnet is widely known in California (Troxel, 1957), especially as
a gangue mineral in contact metamorphic tungsten deposits. Most of
the tungsten ores must be finely ground to recover the scheelite, leav-
ing the garnet in too fine a state to be useful as an impact abrasive.
However, some tailings from ores treated in World War I in the
Tungsten Hills west of Bishop, California, were fairly coarsely ground
MINERAL AND WATER RESOURCES OF CALIFORNIA 169
to pcass 8 to 14 mesh. Some garnet concentrates were derived from
these tailings in 1938-40 and marketed for impact abrasives at a price
of $18 a ton. Small amounts were produced intermittently through
1955, the last year of recorded output, and several thousand tons were
shipped in 1954-55 (Calif. Mining Jour., 1954, v. 23, no. 11, p. 16).
Despite widespread distribution of garnet in California, the outlook
for production is poor. Although the abrasive quality of the garnet
in many deposits is unknown, most garnet produced would be too fine
grained for impact abrasives, and garnet for other uses cannot be
produced competitively unless markets are large enough to warrant
expensive processing plants to treat deposits less favorably endowed
than those of New York.
Selected References
Ambrose, P. M., 1964, Abrasives, in Minerals Yearbook 1963 : U.S. Bur. Mines
Bull., V. 1, p. 191.
Hill, C. H., Sr., 1959, Grinding the Lick Observatory mirror : Grinding and Finish-
ing, V. 5, no. 3, p. 26-27.
Levin, S. B., 1960, Genesis of some Adirondack garnet deposits : Geol. Soc. America
Bull., v. 61, p. 519-565.
Troxel, B. W., 1957, Abrasives, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 23-25.
Yogel, H. H., 1960, Garnet, in Ladoo, R. B., Abrasives, in Industrial Minerals
and Rocks, 3d ed. : Am. Inst. Mining Metall. and Petroleum Engineers Trans.,
p. 9-13.
GEM STONES
(By E. B. Gross, California Division of Mines and Geology, San Francisco,
Calif.)
Gem materials, both precious and semiprecious, include minerals
and organic substances that are used for personal adornment, orna-
mental objects, and decorative and special industrial purposes. In-
dustrial gem materials include inferior grades of diamonds and other
hard stones which are used for instrument bearings, and cutting tools
and abrasives. Synthetic gems with compositions identical with natu-
ral gems are being used in increasing quantities in the industrial ap-
plications as substitutes for natural gem materials. Synthetic sap-
phires are used in needle valves, lasers, dielectric wafers, and optical
instruments. Imitation gem materials which attempt to resemble
natural or synthetic stones are not considered gem stone commodities.
Of 135 different substances that have been used for ornamental pur-
poses, only about 60 mineral species have most of the attributes to
qualify as gem stones.
A gem material, to be classified as such, must have certain physical
and chemical properties, namely : resistance to abrasion, transparency,
usually high refractivity to light, hardness (preferably 7.5 or greater,
Mohs' scale), lack of strong parting or cleavage, and absence of in-
ternal and external flaws. Besides the above characteristics, a gem
stone must have, above all, beauty of form and color, and be rare. An
other essential factor for many gem stones is the quality of adapt-
ability to faceting and polishing.
Only certain minerals — diamond, corundum (ruby and sapphire),
chrysoberyl (alexandrite), and beryl (emerald) satisfy most of the
above characteristics and are customarily considered precious gems.
67-164 O — 66 — pt. I 12
170 MINERAL AND WATER RESOURCES OF CALIFORNIA
Semiprecious inorganic gem stones and organic gem materials (jet,
amber, and pearl) comprise the bulk of the gem materials. The
semiprecious gems do not have all the essential attributes of precious
gems, yet many are desired for personal adornment. Most semi-
precious gem stones are silicates which include andalusite, benitoite,
beryl (aquamarine, morganite) golden cordierite (iolite), diopside,
enstatite, epidote, feldspar, garnet, idocrase, jadeite, lazurite (lapis
lazuli), nephrite, olivine (peridote), phenacite, rhodonite, scapolite,
sodalite, sj^hene, spodumene (kmizite), topaz, tourmaline, zircon, and
zoisite (thulite). Some colored varieties of quartz, such as amethyst,
rose, citrme, aventurine and rock crystal, are classed as semiprecious
stones. A few oxides, such as hematite and spinel, and phosphates,
such as lazulite and turquoise, may be classed as semiprecious, although
the phosphates generally are soft. Obsidian, although not strictly a
gem stone, is of commercial importance in California.
Many of the semiprecious stones are polished in rounded form,
cabochon, or cut into rectangular or square shapes with few facets
because of their low refractivity. Gems may be given special treat-
ment, such as heat or X-ray ludiations, usually to improve the color ;
the color change may be permanent or temporary depending on method
of treatment.
Most gem stones are faceted or polished to increase their beauty
and value. The various cuts mclude brilliant, baguette, marquise,
pear shape, step, emerald, and lens cut. The truly precious gems,
after cutting and polishing, bring very high retail prices depending
on quality and number of carats (one carat=0.2 grams). Because
of high duties applied to cut gems, however, most importers ship gems
in the natural state to the United States ; these subsequently are faceted
in New York or Los Angeles. Also, gems are cut in England, north-
ern European countries, India, and Burma. In 1963, the retail value
of a one-carat diamond ranged from $575 to $1,650. Emeralds have
the same range of values, because of their rarety. Alexandrites are
about $400 per carat, while rubies and sapphires vai-y considerably in
price, depending upon color, adaptability to faceting and polishing,
and absence of flaws. Their range is between $200 to $800 per carat,
with ruby commanding the higher price. Semiprecious stones and
organic gems bring much lower prices, in the range of $5 to $100
per carat.
The sales of synthetic gems have not affected those of natural stones,
except for special industrial uses. These include synthetic diamonds,
corimdum, and spinel. Synthetic rutile (titania) and (fabulite), a
strontium titanium oxide, have beauty because of their extreme re-
fractivity, more brilliance than diamonds, but they lack durability.
In recent years, emerald has been made in large ciystals synthetically
by the Chatham process in San Francisco. The synthetic emeralds
also command higli prices.
The geologic occurrences of gem stones is varied. Many of the most
valued gems are primary constituents of igneous rocks. Ultramafic
rocks occurring in plugs or dikes contain diamonds disseminated
irregularly throughout the rock. Other gems found in mafic rocks
are sapphire and ruby, enstatite, olivine, and garnets (pyrope and
uvarovite) . More acidic igneous rocks contain notably garnet, sphene,
MINERAL AND WATER RESOURCES OF CALIFORNIA 171
I'utile, topaz, and zircon. Alkaline igneous rocks occasionally contain
gem quality garnet, corundum, zircon, and rutile. Pegmatite dikes as-
sociated with granitic and syenitic igneous bodies include the greatest
variety of gem stones. They have yielded beryl, chrysoberyl, dan-
burite, cordierite, sphene, tourmaline, spodumene, topaz, lazulite,
apatite, and zircon. Many of the best formed gems have been ob-
tained from miarolitic cavities in pegmatites. The world's best known
and most productive gem-bearing pegmatites are in Minas Geraes
province of Brazil. Most emeralds have come from pegmatites in
Columbia, and sapphires and rubies from deposits in India and Ceylon.
Metamorphic rocks have produced gem andalusite, lazurite, and
spinels, ancl contact deposits have yielded apatite, cordierite, corun-
dum, axinite, idocrase, epidote, and garnet. Nephrite and jadeite
have formed by hydrothermal processes at the contact of igneous
rocks with serpentine. Hydrothermal vein deposits have been the
source for datolite, and various types of quartz (such as amethyst,
rock crystal, jasper, agate, and citrine), also benitoite, opal, fluorite,
and topaz. Many of the above minerals are found in gem-bearing
placers, some of which are richer than the primary deposits. Most
gem minerals are chemically inert, resistant to abrasion, and thus be-
come concentrated in residual soils and in heavy stream and beach
placers.
The value of United States production of gem stones has increased
from $1.2 million in 1960 to $1.4 million in 1964, a small value com-
pared to imports of $192.5 million in 1960 and $265 million in 1964.
Nearly 88 percent of the total imports are diamonds, chiefly from
Africa. Consumption of gems in the United States far exceeds its
exports.
More than 60 gem minerals, mostly semiprecious, are produced com-
mercially from domestic sources. At present, California and Oregon
rank first in semiprecious gem stone mining in the United States, each
producing about 14 percent of the total. For the last few years, the
semiprecious gems mined in California included jade, obsidian, tour-
maline, turquoise, jasper, opal, and various minor mineral specimens
which in value amounted to $200,000 annually.
The earliest gem collecting in California was by Indians who ob-
tained tourmaline and turquoise from Riverside and San Diego Coun-
ties. The first recorded discovery was made by Henry Hamilton in
1872 at Thomas Momitain in Eiverside County (Wright, 1957) . Tour-
maline float was noted from a pegmatite dike. In 1892, tourmaline
was f omid in the Pala district followed by a very rich tounnaline-bear-
ing pegmatite discovery m 1898 at Mesa Grande. Commercial gem
mining in California was most active in a pegmatite zone, about 25
miles long. This comprised three major districts: Pala, at the north-
west end, Rincon, and Mesa Grande, near the southeast end, all within
the Peninsular Ranges in San Diego and Riverside Counties (see fig.
25). Most intensive mining in Mesa Grande area was during 1900-
1910 and in the Pala area during 1903-1914 (Wright, 1957) . Although
tourmaline was the chief commodity, other gems such as spodumene
(kunzite) and gem quality beryl were mined. Incomplete production
statistics for the three areas indicate a total value of $319,200 for Pala,
$2,000 for Rincon, and $814,000 for Mesa Grande.
172
MINERAL AND WATER RESOURCES OF CALIFORNIA
'^•'" 123- 122= 121- 120-
"^'TBZ^V-T- ' \ 1^ r ^ r -L "2- EXPLANATION
^*»?( •^ ) I 11 ' ^ ("'° I GEM STONE MODE OF OCCUItRENCE
\\5: ; S I s K ifv o\ L' v/SN' \^5 ^' AS"^*"" -----petrified wood, concretions
nK-h.AMATJ^P<\r--^ 9^"°T™ ' 3. Ben.toite ,ei„
I \ jT ^ --• lL ■ { > \ *■ Chrysopr.se siUcified serpentine
( IM fAKJ-NIT A ^K r7^7\ 'n 1 — i^""i 5. Corundum vein
^l._A \M«)U-|S^TA5<NS/ \ I ^\Z141- 6. D..™o„d detrit.l deposits
Euivkaj^^ \ \ / ou Lt. I I ^ \. '■ Garnet tactite, vein, pegmatite
/7 1 \l TRINITY "^ /-^ l\^''%. I 0 rT"
/ 1 \ y ^M J CAsCAbE \ <^ I 9- Jxieite,
( ^ \ /^ /^"^^ '"t _.^ [,_. \ -y^ : Nephrite - -hvdrot herma 1 replacement,
I S l\. «;^'"' " V^O u N Va I N6,_j^^^>4ll veins
\^ , j w^si \ ^*^ .^ ^^ v\^^ ■ 10. Lapis Lazuli-- -metamorphosed limestone
40'-XL {} r^'^^"*MA^i2^/^ ■■=%,; 11. Obsidian lavaflo.s
\q'%-. q*' \ -'(•5 Tfl " 12- Opal vein, petrified wood
\-a'\ \ \ V \S^ ^. % '3. Rhodonite vein
]■("%. ' AenV /■ BIT&E ,"V' SIERRa~\1 '*' Spodumene pegmatite
/ \^ ^: j r Q\; \^/ I _tt'~^ * '5* Top'* volcanic rock, pegmatite
( •^ 0\ 4-.V---ja|4, \,^<5^''3^NEVADa1 ■• '6- Tourmaline pegmatite
, V O / itiW A*''^r? ^..^^ ' '■• 17.,,'Du-quoise vein
124- \ ^j^""- ft '!r^'^V^"^''-Q >'■ -t-39° *• Pala district
\ y . l'^ tSacrarrbcui D# c •'Or •/• C. MesaGrande district
~^^H.Cy%->\\' 1^\K /TUOLUMNE ■AmU^OV -\~^&'
VoNTEREV^^^y ,^^^4^0\ -V 12^3,.
V^LUis Ab-"-""^. \ Yi^\^ ., *«16 ""^l^"
( -^ "-K KERN \^ • • _ "\
r^*''"^H-~--\Z- ^' ifsAN berna'r'dino \
? Itg^RBARAj^VxALOSANGELESJ ,'^ • 1 * Y
^^"-^^^^^XlJl^^^rr^ ^ DESERT y
34-+ ^ o ^..^■••^^^^^•^^^ ^-^^^'^^v.^--^ r
121- • ^^V>\°2fVX^'' ° ' ?
0 50 100 150 MILES ^X */^ ^ \. X^ /
' ^ ' ^ V'^^'^^A'^^^ \
33"+ 4- \ + I^^'^'^'^'^CtrooghW
120° 119° 118° f«suiDK<p> .TVJ-- r
117°
FiGUBE 25. Selected gemstone localities in California.
Gem minerals have been recovered also from scattered pegmatites
in Coahuila, Red, and Thomas Mountains in Riverside County. Other
districts in San Diego Comity have included Ramona, Julian, and
Aguanga Mountains. Since 1925, most of the mines in the above dis-
tricts have been idle on a full-time commercial basis, but mterest of
mineral collectors has remained high, so that part-time operators have
screened dumps and midertaken sporadic mining in recent years.
Other gem operations Avithin the State have been minor. Prior to
1920, an estimated 500 diamonds have been recovered from placer min-
ing for gold in the westeni foothills of the Sierra Nevada (Murdoch
and Webb, 1956) . Few of the diamonds exceeded 2 carats. Benitoite
(BaTiSiaOo), a mineral found in blue crystals, occurs only m San
Benito County, California, and was actively mined from 1907-1909.
MINERAL AND WATER RESOURCES OF CALIFORNIA 173
Since then, few crystals of gem quality have been found. Chrysoprase,
a green variety of chalcedony, was found in 1878 near Visalia, Tulare
County. Other occurrences of chrysoprase in veins were developed in
Tulare County and were exploited between 1878 and 1911. Massive
idocrase ( calif ornite) was mined near Happy Camp, Siskiyou County,
from 1900 to 1911. Since then, mineral collectors have obtained small
quantities from the deposits. Jadeite and nephrite have been mined
sporadically in many small deposits since 1930 m the Coast Ranges,
chiefly in Monterey, Marin, Mendocino, San Benito, and San Luis
Obispo Counties (Crippen, 1951; Yoder and Chesterman, 1951; and
Chesterman, 1951 ) . More recently, 1963, nephrite-j ade has been found
m Mariposa County. All occurrences are in veins, lenses, or pods asso-
ciated with serpentine.
Gem quartz crystal occurrences are known in Amador, Inyo, Lake,
Mariposa, and Tulare Counties. Only two turquoise deposits have
been developed, these for a brief time (1903-1909) in San Bernardino
County. Miscellaneous gem materials such as obsidian, agate, jasper,
rhodonite, opal, and other materials useful for lapidary work have
been collected in recent years, but large-scale mining of gem stones has
been inactive for years.
California will contmue to rank high among the States in production
of semiprecious gem stones. However, most new discoveries will be
found by mmeral collector and prospectors. Possible sources include
pegmatites from both the Penmsular Ranges and from scattered dikes
along the western foothills of the Sierra Nevada. Contact meta-
morphic bodies of the SieiTas might yield gem quality epidote, garnet,
sphene, and spinel. Nephrite-j ade, some of good cutting and polish-
ing quality has been found in Mariposa County. Other deposits might
be exposed under similar geologic conditions elsewhere in the State.
Jade (jadeite and nephrite) potential is still promising in the Sierra
Nevada and Coast Ranges, where serpentine is abmidant. Desert
areas of southeastern California are possible locations for new agate
and turquoise occurrences.
Selected References
Chesterman, C. W., 1951, Nephrite in Marin County, California : California Div.
Mines, Spec. Rept. lOB, p. 1-11.
Crippen, R. A., 1951, Nephrite jade and associated rocks of the Cape San Martin
Region, Monterey County, California : California Div. Mines Spec. Rept.
lOA, p. 1-14.
Hanley, J. B., 1951, Economic geology of the Rincon pegmatites, San Diego
County, California : California Div. Mines Spec. Rept. 7B, p. 1-24.
Jahns, R. H., and Wright, L. A., 1951, Gem and lithium-bearing pegmatites of
the Pala District, San Diego County, California : California Div. Mines Spec.
Rept. 7A, p. 1-71.
Jahns, R. H., 1960, Gem stones and allied materials, in Industrial Minerals
and Rocks : Am. Inst. Mining Metall. Engineers, p. 383--441.
Kunz, G. F., 1905, Gems, jewelers' materials, and ornamental stones of Cali-
fornia : California Mining Bur., Bull. 37, p. 1-171.
Murdock, J. and "Webb, R. W., 1956, in Minerals of California. California Div.
Mines, Bull. 173, p. 452.
Schlegel, D. M., 1957, Gem stones of the United States : U.S. Geol. Survey Bull.
1042G, p. 203-251.
U.S. Bureau of Mines, 1965, Commodity data summaries, p. 56-57.
Wright, L. A., 1957, Gem stones, in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176, p. 205-214.
Yoder, H. S., and Chesterman, C. W., 1951, Jadeite of San Benito County, Cali-
fornia : CalifjOrnia Div. Mines Spec. Rept. IOC, p. 1-8.
174 MINERAL AND WATER RESOURCES OF CALIFORNIA
GEOTHERMAL ENERGY
(By D. E. White, U.S. Geological Survey, Menlo Park, Calif., and J. R. McNitt,
California Division of Mines and Geology, San Francisco, Calif. )
Introduction
Geothermal energy, or the natural heat of the earth, is useful in
generating electricity and for space heating. Total world utilization
of geothermal energy is roughly equivalent to 1 million kw, which is
small in comparison to the major sources of energy. The first steam
well for power w^as drilled in Larderello, Italy, in 1904; present Italian
production capacity is about 350,000 kw. No major interest was
shown by other countries until the 1950's when New Zealand first
demonstrated that very hot water tapped at depth (rather than
steam) can yield steam of adequate quality and quantity to be com-
mercially attractive. As the hot w^ater flows into and up the well and
pressure decreases, some water flashes into steam and both water and
steam erupt to the surface like a continuously erupting geyser. Pro-
duction capacity in New Zealand in 1965 is 182,000 kw.
The Geysers steam field in California, the only commercially pro-
ductive area in the United States (1965), first attracted interest in the
1920's; exploration proved that natural steam without liquid water
could be produced from wells drilled a few hundred feet deep. The
steam was similar in temperature and pressure to that of Larderello,
but the commercial climate was not then sufficiently favorable. In
1955 exploration was again undertaken, eventually resulting in suc-
cessful generation of power by 1960 ; a second-stage unit was installed
in 1962 and construction of a third stage is underway in 1965; wdien
completed, total capacity will be 51,000 kw. Actual production of
power by year is shown in table 20.
Within the United States, California leads all other states in areas
explored (15 of total of about 30; see table 19). In addition to The
Geysers, two other very promising areas in California are the Salton
Sea and Casa Diablo.
Engineering aspects of geothermal energy are summarized by
Smith (1964) and economic aspects by Kaufman (1964). The pro-
ceedings of the Ignited Nations Conference on New Sources of Energy,
Rome, 1961 (see citation for Smith, 1964) contains a large variety
of papers on general principles and individual areas of the world.
Geologic Occurrence
The earth is a tremendous reservoir of thermal energy, most of
which is too deeply buried or too diffuse to consider as recoverable
energy. In general, temperatures increase with depth: the average
is approximately 1° C. per 160 feet of depth or 1° F. per 100 feet.
Commercial geothermal areas occur where the rate of temperature
increase is at least 2 times the "normal" rate, and 5 to 10 times
"normal" averaged over hundreds or several thousands of feet in depth
is much more favorable. Two important factors determine the eco-
nomic potential of a geothermal area: temperature, and an adequate
supply of water or steam. Except in very porous rocks, most of the
energy of a geothermal reservoir is stored in the solid rocks rather
MINERAL AND WATER RESOURCES OF CALIFORNIA 175
than in water or steam in the pore spaces, as commonly supposed
("\Vliite, 1965) . The supply of water or steam must be large enough,
eitlier within the reserv^oir, or by access of water from outside the reser-
voir, to maintain a necessary rate of production for some minimum
time (large enough and long enough to pay a profit for the
investment) .
Geot hernial reservoirs can be classified into two types: (a) those
with permeable extensions to the surface, permitting escape of thermal
fluids as hot springs and fumaroles; and (b) deep insulated reser-
voirs with capping rocks of low permeability and little or no surface
expression. Gradations exist between extremes of the two types.
Keservoirs related to hot springs are characterized by high near-
surface permeabilities, at least locally on faults and fractures, per-
mitting water, steam, and contained heat to escape. Many hot sprmgs
discharge heat at rates of ten to hundreds of times the "normal"
heat flow of the earth for equal areas. The Upper (Old Faithful)
Geyser Basin of Yellowstone Park is a familiar example. Its esti-
mated heat flow from 1 sq. mi. is about 600 times that of an equal
area of "normal'' crust of the earth (White, 1965). Temperatures
near the surface are very high because of the upward transfer of
enormous quantities of heat in the escaping water and steam — about
90 x 10*^ cal per sec. One important consequence of a convection
svstem of circulating fluids, with vigorous leakage of heat, is that
tne lower part of the system is cooled by inflowing cooler water;
temperatures deep in the system are therefore cooler than would
otherwise exist.
Deep reservoirs with little or no surface expression require a perme-
able reservoir rock overlain by impermeable rock such as shale that
provides insulation and also inhibits convection loss of fluids and heat.
At Larderello, Italy, exploration was first focused near feeble nat-
ural springs, which were leakages from the system. Other reservoirs
have since been found with no surface expression other than high
rates of temperature increase with depth. The Salton Sea geothermal
area in California is an example of a deep insulated reservoir with
very meager natural leakage.
Most geothermal systems are dominated by liquid water, coimnonly
much above 100° C (212° F) because of the high existing pressures.
In such systems, steam can form by boiling near the surface, as the
hot water rises and pressure decreases sufficiently. In a very few
explored systems (Larderello and nearby areas of Italy and The Gey-
sers, California), the heat supply is so high and the rate of flow of
fluids through the system so low that the available water is converted to
steam, even where pressures exceed 300 pounds per square inch. Ex-
perience is showing that these dry steam systems are rare and that
extensive utilization of geothermal energy must depend largely upon
steam that can be "flashed" from hot waiter with release of pressure.
Occurrences in California
The known hot spring areas of California are shown in figure 26
(modified from Stearns, Stearns, and Waring, 1937, plate 15).
Fifteen areas have been explored for geothermal energy (table 19
and figure 26). Three areas of particular interest are described
briefly below :
176
MINERAL AND WATER RESOURCES OF CALIFORNIA
123°
122°
EXPLAN/kT I ON
1 Explored for geothermal encrgv
T Numbers keyed to table
80 C t o boi 1 ing
20 to 80 °C
tENN / BL-ftTE y siggRj^
Qi I / "i I ^^'^ ;.
.-^•U: \ V0L0\-i-A'EL DORa'dO,- N^..
119°
Ksfe-
ISOLANOf
123-s^;
?A:
\
TUOLUMNE 1\i»(Jno\ -|- 3
.V^
t'^X ..,0^^
/..__ „ ,
MARIPOSA/ '«
\
'^..-*^.'
S'
»NT*C • >\MERe<9
sAfi-A ^-
'1 xV'-FRESNCf
\pENITCf|\-7 ,y\
— X
Bishop 'v
117°
37°
> ^\.
I N Y O ^ \
Monterey
LARK
3S°+
122°
12l-tv36<
\
^1.°
N/IOJA-VE -|^\35°
SAN* BERNARDINO '^
100
3.°+
121°
150 MILES
O^.
ES^
R IX
^
33°
119°
-\- ) SAN DIEGCf
118° ?*s«i<T)i»e"
»*SU< Bi'
DESERT '^i
^'
SIDE {
/
JSAUTON \ -=,33°
116°
115°
117°
Modified from Stearns, Stearns,
and waring, 1937, plate 15
FIGURE 26. Thermal springs of California, showing localities that have been
drilled for geothermal energy (numbers refer to table 19) .
The Geysei-s, Sonoma Coimty, California (McNitt, 1963), and re-
lated areas (table 19) occur along a five-mile length of a northwest-
trending and steeply dipping fault zone. Three areas are being
developed, including The Geysers, Sulphur Bank, one mile to the
Avest, and The Little Geysers, four miles to the southeast. Upper
Tertiar}' volcanic rocks lie to the south and east of The Geysers, and
the Clear Lake volcanic field of Quaternary age is less than 20 miles
to the northeast . However, the geothermal zone is underlain by almost
impermeable sandstone, basalt, and serpentinite of the Jurassic and
Cretaceous Franciscan Formation.
MINERAL AND WATER RESOURCES OF CALIFORNIA
177
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178 MINERAL AND WATER RESOURCES OF CALIFORNIA
Dry steam is obtained by drilling wells into the fault zone. The
wells range from several hundred to 5,000 feet deep. Static wellhead
pressures range from 100 to 500 pounds per square inch and seem to
reflect the hydrostatic pressure and thickness of a groundwater cover
overlying the steam (McNitt, 1963). Measured flow rates from in-
dividual wells range from 15,000 Ib/hr at 78 psi to 184,000 Ib/hr at
120 psi. The heat content of the steam averagas about 1,200 Btu per
pound (670 cal per gm). Power production since 1960 is listed in
table 20.
Table 20. — Production of electricity in kilowatt-hours. The Geysers Poicer Plant,
Pacific Gas & Electric Co., Sonoma County, California (excluding station uses;
data from A. W. Bruce, Pacific Gas d Electric Co.. 1965)
Year: Production
1960 33, 576, 944
1961 94, 019, 840
1962 100. 461, 120
1963 167, 9.52, 960
19&4 203, 790, 080
In the Salton Sea area, very saline brine was discovered in reservoir
rocks below a capping of fine-grained sediments. Details of tempera-
tures and production capacity have not been released for publication.
Temperatures of 270°C to 370°C are indicated near 5,000 feet (White,
1965). The exploration wells have all produced at rates that are
qualitatively impressive; they are distributed through an area at least
6 miles long and 2 miles wide adjacent to Salton Sea. Published geo-
physical data (summarized in McNitt, 1963, fig. 14) suggest that an
almost equal area extends out under the sea.
The brine has a salinity of about 30 percent, consisting dominantly
of sodium, calcium, and chloride but with very high contents of potas-
sium, iron, manganese, zinc, lead, copper, silver, and other rare
elements. Economic interest is focused about equally on the energy
and potassium contents of the brine. Other by-products of value,
such as lithium, silver, and other metals, may also be recoverable.
The Casa Diablo area is in the large structural depression of Jjong
Valley, which may be related to extensive volcanic activity during the
past million years (McNitt, 1963; Wliite, 1965). Porous and perme-
able volcanic tuffs and breccias are probably interstratified at depth
with lava flows; in some respects this area is comparable to Wairakei,
New Zealand. Ten wells have been drilled in less than 2 square miles,
and most of these have produced satisfactorily.
Problems That Threaten Broad Utilization
The presence of reservoirs sufficiently high in temperature and in
supply of natural fluids must first be proved by exploration. Hot
water areas are likely to be the most abundant but rapidly cooled water
may deposit either CaCOs or Si02 in wells and treatment plant ; other
chemical substances, such as boron, arsenic, and salts may constitute
effluent problems that require treatment or subsurface disposal. In
addition, geothermal exploration is not adequately covered by existing
state and federal laws; unsympathetic treatment can easily discourage
the development of a promising new natural resource.
MINERAL AND WATER RESOURCES OF CALIFORNIA 179
Appraisal of Regions
The appraisal of a region must be based on rates of temperature in-
crease that are likely to occur with depth, and the probability of
finding adequate reservoir rocks that will yield natural fluids to
wells in required quantities. We have adequate temperature -depth
data only from sedimentary basins that have been explored for oil
and gas. Most of these are characterized by nearly "normal" rates
of increase rather than the abnormally high rates demanded for geo-
thermal energy. The Salt on Trough (fig. 26) is one outstanding
exception, and moderately high temperatures have also been reported
locally in the Transverse Ranges and the Great Valley.
In other regions of the state, data on geothermal gradients and con-
ducted heat flow are very inadequate. We can hypothesize that ther-
mal springs are abundant where heat flow is high and permeable struc-
tures permit water to circulate deeply. Other regions may lack ther-
mal springs because their average heat flow is too low. A combination
of these factors probably explains the scarcity of thermal springs in
the Sierra Nevada, the Klamath Mountains, and most of the Cali-
fornia Coast Ranges.
The required heat sources are most likely to occur in regions of
Pliocene and Quaternaiy volcanism. The clusters of thermal springs
associated with Quaternary volcanic extrusions near Mono Lake,
Mount Lassen, Modoc County, Lake County, southern Inyo Comity,
and Salton Sea attest to the importance of volcanism in supplying
abnormally high rates of heat flow.
The most favorable regions in California are the Salton Trough,
the California segments of the Modoc Plateau and Great Basin; and
local parts of the California Coast Ranges and the Southern Cascade
Momitains.
Selected References
Kaufman, Alvin, 1964, Economic appraisal of geothermal i)Ower: Mining Eng.,
Sept. 1964. p. 62-66.
McNitt, J. R., 1963, Exploration and development of geothermal power in Cali-
fornia : California Div. Mines and Geology, Spec. Rept. 75, 45 p.
Smith, J. H., 1964, Harnessing of geothermal energy and geothermal electricity
production : United Nations Conf. New Sources Energy, Rome, 1961, Proc.,
v. 3, p. 3-59.
Stearns, N. D., Stearns, H. T., and Waring, G. A., 1937, Thermal springs in the
Unitetl States: U.S. Geol. Survey Water-Supply Paper 679-B. 206 p.
White, D. E., 1955, Violent mud-volcano eruption of Lake C>tv hot springs,
northeastern California : Geol. Soc. America Bull., v. 66, p. 1109-1130.
, 1965, Geothermal energy : U.S. Geol. Survey Oirc. 5ly.
White, D. E. and Roberson, C. E., 1962, Sulphur Bank, a major hot-spring quick-
silver deposit, in Petrologic Studies — A Volume in honor of A. F. Buddington :
Geol. Soc. America, p. 397-428.
GOLD
(By W. B. Clark, California Division of Mines and Geology, Sacramento, Calif).
Of the various properties that, give gold an outstanding place in
the world of metals, the most important are resistance to cori'osion,
reflectivity, malleability, and high specific gravity. Man has used
gold as a medium of exchange and in ornaments and the arts since
180 MINERAL AND WATER RESOURCES OF CALIFORNIA
prehistoric times. The principal use at present continues to be in
monetary systems or in coinage. Federal controls closely regulate
the ownership and distribution of gold, except for gold in the natural
state. Although it is illegal to possess gold coins other than as curios
in the United States, they are minted and circulate freely in a number
of other countries. Considerable amounts are used in jewelry and
the decorative arts, including watch cases, rings, gold leaf, gilding,
gold plating and decorative finishes on ceramics and other materials.
The growth of these uses has paralleled the growth in population
and gross national product. Substantial amounts are used in dentistry
and lesser amounts in the chemical industry and glass making. The
development of new scientific devices and instrumentation has been
reflected in increasing uses of gold.
To many persons, gold is California's best-known metal. It was
the principal attraction to the early-day pioneers and stimulated the
State's growth for many years.
In California, the principal primary deposits are mesothermal gold-
quartz veins that are associated with the intrusion of granitic bodies
and occur either in slates, schists, and greenstones that have been
intruded by the granitic bodies, or in the granitic rocks themselves.
The veins range from a fraction of an inch to tens of feet in thickness;
many deposits consist of a series of parallel of branching quartz
stringers separated by slabs of country rock.
In a typical deposit, the gold occurs as microscopic grains, plates,
or threads in the quartz and is commonly associated with varying
amounts of pyrite and small amounts of other sulfides; gold associated
with tellurides has been found, the most notable occuiTences being
at Carson Hill. The extent of the ore shoots varies greatly. Many
extend to depths of only a few hundred feet; in others, such as the
veins at Grass Valley or in the Mother Lode, the deposits extend to
inclined depths of 5,000 to 10,000 feet.
Massive or vein-like replacement deposits of pyrite that contain cop-
per and zinc also contain some gold and silver. Also, the iron oxide-
rich gossans that cap such deposits have yielded substantial amounts of
gold. The most important deposits have been in the Shasta and Sierra
Nevada Foothill copper-zinc belts and the Plumas County copper
belt. Gold is a constituent of lead-zinc and lead-silver replacement
deposits in the Great Basin. It is a minor constituent of contact
metamorphic tungsten and copper ores in the Sierra Nevada and of a
few mercury deposits in the Coast Ranges.
A number of important epithermal gold deposits are found in Cali-
fornia, the most productiA^e being the Bodie, Mojave, and Rand dis-
tricts. These deposits consist of gold-bearing zones of alteration and
silicification in igneous or metamorphic rocks. The ore commonly
consists of silicified breccia containing fine free gold and disseminated
sulfides. The zones of alteration often are extensive and usually have
a bleached appearance. In a few deposits, the gold is associated with
manganese.
Because of its high specific gravity and resistance to weathering,
gold is easily concentrated in placer deposits; vast amounts have been
recovered from California's placers. All of the streams that flow
through the gold-bearing regions have been productive. The gold
MINERAL AND WATER RESOURCES OF CALIFORNIA 181
particles are flat or rounded and range from microscopic size "flour
gold" to nuggets 100 or more ounces in weight. Many large nuggets
have been found in California, especially in Alleghany, Columbia,
Downieville, Magalia, and Sierra City districts. The gold particles
are everywhere associated with black sands composed of magnetite and
smaller amounts of ilmenite, chromite, zircon, garnet, pyrite, and in
some places platinum.
The placer deposits in California range from early Tertiary to
Recent in age. The Recent placers are in and adjacent to the present
streams; the older gravels are on terraces adjacent to the present
channels or high on the interstream ridges. The extensive older
Tertiary channels in the northern and central Sierra Nevada have
been preserved by a thick cover of volcanic rock. They are charac-
terized by abundant quartz pebbles and cobbles and in places by coarse
nuggets.* There are dry desert placers in several areas in southeastern
California. In these deposits, small rounded grains of gold are found
in loose sand. Gold, usually in very fine grains, has been recovered
from placers on some of the beaches along the coast.
Gold was first recovered in California some time between 1775 and
1780 on the lower Colorado River. These early operations were on a
small scale and lasted only a few years. They extended west and north
into the Cargo Muchacho and Picacho districts. Later in the 1820's,
1830's, and 1840's, placer gold was recovered near San Diego and in
the San Gabriel Mountains. None of these early operations had much
significance in the development of the State. On Januaiy 24, 1848,
James W. Marshall made his historic discovery at Sutter's Mill at
Colma on the American River. Soon afterward, the gold rush was in
full sway as thousands of gold seekers poured into California. Gold
also was discovered in the Trinity River by Pearson B. Reading in
1848. In a few short years, most of the State had been explored, and
many areas had been permanently settled. California's gold rush had
a profound influence on the entire western United States and many
parts of the world.
The flush production of the first few years of the gold rush was
from rich and virgin surface placers. In 1851, the State's output
attained an all-time high of almost 4 million ounces valued at 81.2
million dollars. As the rich surface placers declined in the middle
and late 1850's, river mining and then hydraulic mining became the
chief gold sources.
As a result of hydraulic mining, which was first done in 1852 near
Nevada City, Nevada County and at Yankee Jim's in Placer County,
large quantities of evacuated material w^as allowed to flow into the
rivers, and was alleged to cause flooding and silting of farmlands
downstream. This eventually led to litigation between farmers and
the hydraulic miners. In a famous court case in 1884 (Woodruff vs.
North Bloomfield Gravel Mining Co. (16 Fed. Rep. 25)), Judge
Lorenzo Sawyer issued an injunction prohibiting the dumping of
debris into the Sacramento and San Joaquin Rivers and their trib-
utaries. Injunctions against other mines followed. A few mines
constructed tailings dams or reservoirs and continued to operate for a
few years. For a short time, drift mining of buried gravel channels
partly made up for the loss of placer gold production from hydraulic
mines.
182
MINERAL AND WATER RESOURCES OF CALIFORNIA
In 1876, rich ^old-bearino; deposits Avere discovered at Bodie in
Mono County. The rush to tliat district continued until about 1888.
In 1893, the discovery of "cold in Goler Gulch in the El Paso Moun-
tains in eastern Kern County led to the discovery and the resulting
rush to the nearby Band district. Other productive southern Cali-
fornia districts of the 1890's and early lOOO's were the Cargo Muchaco,
Stedman, Picacho, and Mojave districts.
During these years, great improvements were made in mining and
milling methods and equipment which enabled many more lode de-
posits, especially larger but low-grade ores, to be profitably mined.
The first successful bucket-line dredge was started on the Feather
River near Oroville in 1898. Gold dredging soon became a major
industry that has continued for more than 65 years.
The general prosperity, that began during World War I and con-
tinued through the 1920's, witli accompanying high costs, caused a
significant decrease in gold production in California. In 1930, out-
put started to rise because of the depression and resulting low operat-
ing costs. This rise was accelerated in 1934 when the price of gold
was increased from $20.67 to $35 per fine ounce. Many mines were
reopened, and there was much exploration which resulted in significant
discoveries. Thousands of miners were employed in the quartz mines
at Grass Valley, Nevada City, Alleghany, Jackson, Jamestown, Sutter
Creek, and Mojave. There were many active bucket-line dredges,
and dragline dredges became important gold sources. In 1940, gold
production amounted to 1,455,000 fine ounces valued at nearly $51
million, the highest figures since the gold rush. Most of the major
events are graphically recorded in figure 27.
ALL - T IME H I GH OF
J81 .2 MILL ION
) DECLINE OF
SURFACE PLACERS
HIGH OF $50.9 MILLION
SAWYER DECISION
AGA INST HYDRAULIC
MINING
OUTPUT FROM DREDGES
AND LARGE LODE MINES/
WORLD WAR I I
WAR PRODUCTI ON BOARD
CLOSING ORDER L ■ 208
; INCREASED
OUTPUT FROM
HYDRAUL I C
MINES
PRODUCT I ON
FIGURES ADJUSTED
DEPRESSION
850 1860 1870 1880 1890
1900 1910 1920 1930 1940 1950 1960 1964 1970
Figure 27. California's gold production.
MINERAL AND WATER RESOURCES OF CALIFORNIA 183
World War II caused a precipitous drop in gold production. War
Production Board Limitation Order L-208 was issued in 1942 and
caused the gold mines to be shut down. Order L-208 was lifted in
1945. Some of the dredges resumed operations, and some of the
major lode mines in Grass Valley, Alleghany, and Sutter Creek were
reopened. Gold production increased slightly for 4 yeai*s. However,
in 1950, production resmned its decline because of rising costs and
d.epletion of dredging ground. This trend was accelerated by the
Korean War. The last large mine on the Mother Lode shut down in
1953. Tlie large mines at Grass Valley shut down in 1956, ending a
major industiy that had lasted 106 years. The last dredge in the
Folsom district was shut down in 1962, ending more than 60 years of
operations. The mines at Alleghany, the last active quartz-mining
district, have recently curtailed operations or shut down, and the
dredges at Hammonton, the last major dredging field have gradually
curtailed operations.
Since 1848, California has yielded more than 106 million fine ounces
of gold, valued at 2.42 billion dollars. These figures are far greater
than those for any other State and represent about 35 percent of the
total United States production. In 1964, California's gold produc-
tion amounted to Yl,028 fine ounces valued at $2,485,980 which placed
it fifth among the States in output. Much of this production came
from the three active bucket-line dredges in the Hammonton district
of Yuba County. Some gold was produced from a few small lode
mines in the Sierra Nevada and Klamath Mountains. In addition,
gold was produced from small-scale placer-mining operations, in-
cluding a few dragline dredges, prospectors, skin divers, and "snipers."
Some gold was recovered as a byproduct in sand and gravel plants
along the east margin of the Great Valley and from tungsten and lead-
zinc mines in eastern and southeastern California.
Most of California's gold production has come from five geomorphic
provinces: The Sierra Nevada, which has been by far the most pro-
ductive, Klamath Mountains, Great Valley, Great Basin, and Mojave
Desert. Lesser amomits liave been recovered in the Transverse
Ranges, Peninsular Ranges, and Modoc Plateau, and small amounts
in the Coast Ranges. The distribution of gold-bearing areas is shown
in figure 28.
The Sierra Nevada, the dominant mountain range in California, has
been the source of the bulk of the State's gold output and contains the
largest number of and most productive gold districts. Most of the
primary deposits are associated with intrusions of the granitic rocks
of the great Sierran batholith. The gold-bearing veins occur for the
most part in the belt of metamorphic rocks that extends along the
western slope of the northern half of the range, along the western
foothills, and in granitic stocks that are branches of the main batholith.
In the northern part of the range lie such rich and famous districts
as the Alleghany, Sierra City, Nevada City, and Grass Valley. The
Mother Lode belt lies to the southeast extending from El Dorado to
Mariposa County. It is a system of linked or en echelon gold-quartz
veins and mineralized schist and greenstone that extends from George-
town and Greenwood southeast to Mariposa, a distance of 120 miles.
The placer deposits of the western Sierra Nevada have yielded vast
quantities of gold; some estimates have placed it to be more than 40
184
MINERAL AND WATER RESOURCES OF CALIFORNIA
124'
120
EXPLANAT I ON
Go Id -bear ing area
Lode gold d istr ict
Placer gold district
■
Dradiing field
116°
Figure 28. Gold-bearing areas in California.
percent of the State's total output. They are divisible into the older
or Tertiary deposits which are on the interstream ridges, and Quater-
nary or younger deposits that are found in and adjacent to the present
streams. The Tertiary deposits have been mined chiefly by hydraul-
icking and drift mining and the Quaternary deposits by dredging and
various small-scale placer methods. The gold in the dredge fields
along the east margin of the Valley was derived from the Sierra
Nevada while that from the northern end of the Valley was derived
from the Klamath Mountains.
The Klamath Mountains have been the second most productive area.
MINERAL AND WATER RESOURCES OF CALIFORNIA 185
Here, the largest sources of gold have been the placer deposits of the
Klamath-Trinity-Salmon River system and tributaries to the upper
Sacramento River. Not only has gold been recovered from the present
stream channels but also from adjacent older terrace and bench gravel
deposits. Lode-gold deposits are found throughout the province, but
the most productive have been the French Gulch, Liberty, and Harri-
son Gulch districts. The gold-quartz veins occur in slate and schist
and often are associated with dioritic dikes. Large amounts of by-
product gold have been recovered from the massive sulfide deposits
of the East and West Shasta copper-zinc districts.
The Great Basin and Mojave Desert provinces of eastern and south-
eastern California have been significant sources of gold. The Bodie
district has been the largest source of gold in the Great Basin, while
the Rand, Mojave, Stedman, and Cargo Muchacho district contain the
most productive mines in the ]\Iojave Desert. Moderate amounts of
gold have been mined in the Transverse Ranges, the principal sources
having been the Acton and San Gabriel districts. Moderate amounts
also have been recovered in the Cuyamaca, Julian, and Pinacate dis-
tricts in the Peninsular Ranges and from the Hayden Hill district in
the Modoc Plateau. Gold occurs in a number of places in the Coast
Ranges including the Frazier Mountain district which sometimes is
classified as being in the Transverse Ranges. Gold occurs in beaches
along the ocean usually in very small amounts.
Resource Potential
At the present time, the outlook for gold mining in California is
poor. The few active commercial mining operations are gradually
shutting down. There is very little possibility of a revival of gold
mining under present economic conditions. A small rise in the price
of gold would probably result in an increase in exploration and devel-
opment in some of the more isolated "high-grade'" or pocket mining
districts. However, it seems doubtful if there would be much effect in
the large minmg districts, because of the great expense in recondi-
tioning the mines, because many of the workable deposits have been
largely depleted, and because in many districts land values have so
greatly increased in recent years as to preclude their use in mining
again. Another factor in the mountainous regions in California is
the inundation or the plans to inundate many important mines and
gold-bearing areas by reservoirs. A major change in economic condi-
tions with a resulting large decrease in costs would undoubtedly stimu-
late gold mining in California as it did during the depression of the
1930's. A large rise in the price of gold would also stimulate the
industry in California.
The largest undeveloped gold-bearing deposits in California are:
(1) the deeply buried Tertiary channel gravels in the Sierra Nevada;
(2) unmined terrace deposits in parts of the Klamath-Trinity River
system ; (3) low-grade gravel deposits adjacent to the dredging fields;
(4) gravels too deep to be mined by existing equipment in the Great
Valley; (5) deep but undeveloped veins in the major lode-gold dis-
tricts; and (6) large bodies of mineralized schist and greenstone in
certain districts. In addition, there are extensive zones of alteration
107-164 O — 66 — pt. I 13
186 MINERAL AND WATER RESOURCES OF CALIFORNIA
in certain districts that are known to contain gold values, but which
have not been systematically examined. Most of the above deposits
are too low in grade to be mined commercially under the present
economic conditions. Tlie deeply buried channel gravels and the deep
veins would have to be mined by expensive underground methods. The
large bodies of mineralized schist and greenstone and the wide zones of
alteration could possibly eventually be mined by open-pit and low unit-
cost methods.
Selected References
Averill, O. V., and others, 1946, Placer mining for gold in California : California
Div. Mines Bull. 135, 377 p.
Clark, W. B.. 1957, Gold, in Mineral Commodities of California : California Div.
Mines Bull. 176, p. 215-226.
Clark, W. B., in preparation. Gold districts of California : California Div. Mines
and Geol. Bull.
Ferguson, H. G., and Gannett, R. W., 1932, Gold-quartz veins of the Alleghany
district, California : U.S. Geol. Survey Prof. Paper 172, 139 p.
Gardner, D. L., 1954, Gold and silver mining districts in the Mojave desert region
of southern California : California Div. Mines Bull. 170. chap. 8, no. 6, p. 51-58.
Haley, C. S., 1923, Gold placers of California : California Mining Bur. Bull. 92,
167 p.
Hanks, H. G., 1882, Placer, hydraulic, and drift mining : California Mining Bur.
Rept. 2, p. 28-192.
Hill, J. M., 1929, Historical summary of gold, silver, copper, lead, and zinc
produced in California : U.S. Bur. Mines Econ. Paper 3, 22 p.
Hulin, C. D.. 1925, Geology and ore deposits of the Randsburg quadrangle :
California Mining Bur. Bull. 95, 152 p.
Jenkins, O. P., and others, 1948, Geolc^c guidebook along Highway 49 — Sierran
gold ibelt — The Mother Lode Country : California Div. Mines Bull. 141, 164 p.
Johnston, W. D., Jr.. 1940, The gold-quartz veins at Grass Valley, California :
U.S. Geol. Survey Prof. Paper 194, 101 p.
Joslin, G. A., 1945, Gold, in Economic Mineral Resources and Production of
California : California Div. Mines Bull. 130, p. 122-151.
Knopf, Adolph, 1929, The Mother Lode system of California : U.S. Geol. Survey
Prof. Paper 157, 88 p.
Lindgren, Waldeiaar, 1911. The Tertiary gravels of the Sierra Nevada : U.S.
Geol. Survey Prof. Paper 73, 226 p.
Logan, C. A., 1935. Mother Lode gold belt of California : California Div. Mines
Bull. 108, 240 p.
Yale, C. G., 1896. Total production of gold in California since 1848 by years
according to different authorities : California Mining Bur. Rept. 13, p. 64-65.
GRAPHITE
(By G. B. Oakeshott, California Division of Mines and Geology, San Francisco,
Calif.)
The mineral graphite is a crystalline form of pure carbon and is
characterized by softness, perfect basal cleavage, and a greasy feel.
A commercial distinction made between "amorphous" and "crystalline"
graphite is based solely on relative grain size ; the "amorphous" variety
is the finer grained. The grades and specifications of graphite used
in industry are complex and involved. Particles of crystalline flake
graphite may be as large as 8-mesh ; particles of artificial graphite in
collodial dispersions may be only 5 millionths of an inch in diameter.
The most useful properties of graphite are its resistance to chemical
action and the action of molten metals, its infusibility (graphite does
not melt, but sublimes at about 6500°F), opacity, softness, and perfect
cleavage.
MINERAL AND WATER RESOURCES OF CALIFORNIA 187
A larger tonnage of graphite is used in the United States for foundry
facings (41 percent of the amorphous graphite used in 1963) than for
any other purpose. Consumption of natural graphite in the United
States, by use, in approximate order of decreasing amounts, is in
foundry facings, steel-making, lubricants, refractories, crucibles, filler
for dry batteries, and "lead" pencils.
Presently (1965), natural crucible flake graphite is on the critical
list and is eligible for government financial assistance up to 50 percent
of exploration costs.
Much grapliite has been formed by the metamorphism of carbona-
ceous sediments, including coal, with resultant crystallization of the
carbon. However, some is associated with intrusive igneous rocks
and with pegmatites; the mineral is also a constituent of meteorites.
Graphite in California, all of the amorphous variety, occurs in schists
and gneisses, most, if not all, of which are of sedimentary origin.
From 1865 to 1935, graphite was produced intermittently in Cali-
fornia, but no production has been recorded since. A 50-ton concen-
tration mill was constructed at the Kagel deposit, Los Angeles County,
and produced small-flake graphite between 1918 and 1928. The total
yield of California graphite is estimated to have been about 1,500 tons,
valued at $137,000. The low quality of the graphite, low-grade ore,
the small tonnage of griiphite consumed, and ample world supply are
the principal causes of the lack of production from California for the
past 30 years.
World production of natural graphite in 1963 was 730,000 tons.
The largest producing country was Korea (North and South) ; fol-
lowed in order by Austria, U.S.S.R., China, and the Malagasy Repub-
lic. Statistics for the United States are concealed, so as not to reveal
the production of any one company, as Southwestern Graphite Co. at
Burnet, Texas, has long been the comitry's only producer (Drake,
1964). United States' consumption of graphite in 1963 was 47,000
tons, valued at $6,111,000 (Drake, 1964) .
A third of the counties of California, chiefly in the Sierra Nevada,
Klamath Mountains, Coast Ranges, and Transverse Ranges, contain
graphite schists which have been prospected, but the small production
has come almost entirely from Los Angeles, Tuolumne, Mendocino,
and Sonoma Counties.
Several deposits in Los Angeles County were discussed by Beverly
(1934). Deposits in the Placerita Formation (Paleozoic?), upper
Kagel Canyon, and several in Pacoima Canyon and vicinity in the
western San Gabriel Mountains of Los Angeles County were described
by Oakeshott (1937; 1958). The crude graphite-bearing rock con-
tains 7 to 15 percent graphite in flakes less than 0.25 mm in diameter.
Although graphite is Avidely distributed in pre-Cretaceous meta-
morphic rocks throughout California, owners of graphite deposits in
the State have had difficulty in meeting competition provided by the
higher quality imported material. No change in this situation is
anticipated.
Selected References
Beverly, Burt, Jr., 1984, Graphite deposits in Los Angeles County, California :
Econ. Geology, v. 29, no. 4, p. 346-355.
Drake, H. T., 1964, Graphite, in Minerals Yearbook: 1963, U.S. Bur. Mines,
p. 578-581.
188 MINERAL AND WATER RESOURCES OF CALIFORNIA
Oakeshott, G. B., 1937, Geology and mineral deposits of the western San Gabriel
Moiuitains, Los Angeles County : California Div. Mines Rept. 33, p. 245-248.
, 1957, Graphite, in Mineral commodities of California : California Div.
Mines Bull. 176, p. 227-229.
-, 1958, Geology and mineral deposits of San Fernando quadrangle, Los
Angeles County, California : California Div. Mines Bull. 172, p. 15, 51, 107,
109, 112.
GYPSUM AND ANHYDRITE
(By C. F. Withington, U.S. Geological Survey, Washington, D.C.)
The calcium sulfate minerals gypsum and anhydrite occur in beds
formed by preciptation from saline waters, generally in partly
isolated arms of the sea. Gypsum is hydrous calcium sulfate
(CaSOi'SHsO), generally white or light gray; impurities may color
it dark gray, black, pink, green, or yellow. The most common form
is massive rock gypsum, a compact aggregate of small crystals occur-
ring in beds as much as 100 feet thick. Alabaster is a compact, very
fine-grained variety of gypsum. Gypsite is an impure, earthy mixture
of gypsum (rarely more than TO percent), sand, silt, and clay formed
near the surface in deposits that are seldom more than 15 feet thick
and a few acres in extent. Gypsite is generally gray mottled with
white, buff, or cream; iron may color it pink or red. Other gypsum
varieties include satin spar and selenite.
Anhydrite, calcium sulfate (CaS04), is slightly heavier and harder
than gypsum. It is gray, bluish gray, or white; impurities may color
it red, pink, gray, or black. Anhydrite may occur as isolated crystals
or lenses within a gypsum deposit, it generally replaces gypsum at
depth.
Gypsum ic the more useful of the two minerals ; most gypsmn is cal-
cined to be used as plaster, principally in the manufacture of wallboard
and other prefabricated gypsum products. Uncalcined or raw gyp-
sum is used as a retarder for portland cement and as a soil conditioner.
Gypsite. is used extensively as a soil conditioner. Anliydrite is used
primarily as a soil conditioner and to a lesser extent as a retarder for
Portland cement.
Since 1960 California has led the United States in the production
of gypsum. From 1880, when the first gypsum was produced in the
State at Pomt Sal (Santa Barbara County), through 1964, an esti-
mated 27 million short tons of gypsum was produced. In 1964, pro-
duction was 1,893,000 tons, of which about a million tons was gypsite.
Nearly three-quarters of the gypsite was produced in Kern County
for use as a soil conditioner for the potato and cotton crops in the San
Joaquin Valley (Davis and others, 1963, p. 174) . The annual produc-
tion of gypsum and gypsite since 1945 is given in figure 29. Contrary
to the national trend, the average price per ton of gypsmn in Cali-
fornia dropped between 1945 and 1964, due largely to the increased
use of the less expensive gypsite. Resources of gypsite are sufficient
to supply the State for many years; those of gypsmn are not great
and within a few years most of the gypsmn used in the State will be
imported. Imports of gypsum into California from Mexico and Ne-
vada in 1963 amounted to more than 600,000 tons.
MINERAL AND WATER RESOURCES OF CALIFORNIA 189
Price Per Ton
CSJ
2.400-
2.000-
1.600-
1.200
in
CM
CM
CO
4.800
4.200
3.600
- 3.000
- 2.400
1.800
1 .200
- 600
Figure 29. Production of gypsum in California, 1945-64.
190
MINERAL AND WATER RESOURCES OF CALIFORNIA
Occurrences in California
Gypsum and gypsite occur mainly in the southern part of the State.
In addition to the deposits listed in table 21, gypsum was manufac-
tured as a by-product of magnesium derived from sea water in A'la-
meda County and as a by-product of phosphoric acid in Fresno and
San Joaquin Counties. The gypsum and gypsite deposits are here
described by county ; their distribution is shown on figure 30.
Table 21. — Distribution of calcmnv sulfate in California
County
Type of deposit
Age
Fresno. .
Imperial -
Inyo
Kern
Kings --
Los Angeles.
Merced
Orange
Riverside
San Benito
San Bernardino.-
San Diego (described with Imperial
County).
San Joaquin
San Luis Obispo
Santa Barbara
Shasta
Ventura
Gypsite
Gypsum-anhydrite.
Gypsxim
do
Gypsite
do
do
do— .
Gypsum.
do....
Gypsite..
Gypsum.
do....
do.._
Selenite veins
Gypsite
Gypsum
Gypsum-anhydrite.
GjT)sum
Recent.
Miocene.
Pliocene (?).
Miocene {?).
Recent or Pleistocene.
Recent.
Recent and OUgocene or Miocene
Recent.
Late Cretaceous.
Permian (?).
Recent.
Pliocene and Pleistocene (?).
Tertiary, Permian (?).
Miocene.
(?).
Pliocene to Pleistocene, Recent.
Miocene to Pliocene.
(?).
Miocene and Pliocene (?) .
Fresno County
Gypsite occurs in several small deposits in the northwestern corner
of the county, including those in the Panoche Hills (No. 1) (see fig.
30), and in Tumey Gulch (No. 2) (Ver Planck, 1952, p. 49-51). In
1959, a plant was constructed near Mendota to process the gypsite from
the Panoche Hills, which averages 40 percent or more gypsum; the
overburden contains as much as 18 percent CaS04-2H20 (Kock Prod-
ucts, 1959a, p. 58). The Little Panoche Valley deposit (No. 3) has
yielded some gypsite guaranteed to average 70 percent gypsum, but no
production has been reported since about 1953. Other gypsite deposits
include: Monocline Eidge (No. 4), Oil Fields (No. 5), and those at
Coalinga (No. 6).
Invperial and San Diego Counties
The gypsum deposits in Imperial County, the most extensive in the
State, are in the western part of the county, extending westward into
San Diego County.
Gypsum occurs on the northwest side of the Fish Creek Mountains
and on the northeastern edge of the Vallecito Mountains, Avhere it con-
formably overlies poorly consolidated gray sandstones and conglom-
erates of the Split Mountain Formation of which it is a part (Ver
Planck, 1952, p. 30). Overlying the gypsum are the marine shales
of the Imperial Formation.
The best exposures of gypsum are in the open pit of the United
States Gypsum Co. at the north end of the Fish Creek Mountains
(No. 7). Here it is white to light-gray, massive, fine- to medium-
MINERAL AND WATER RESOURCES OF CALIFORNIA
191
124-
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EXPLANATION
Gypsum occurrence or group
of occurrences
Gypsum mine or group ol nrnes
(active 1957-63)
Gypsite occurrence or group
of occurrences
Gyps ite pit or group of pits
(act ive t957-63)
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Figure 30. Gypsum and anhydrite in California (numbers refer to deposits named
in text).
grained rock gypsum, in beds that range from about 5 to 100 feet in
thickness ; the thicker sections of gypsum appear to liave been concen-
trated along the crests of minor folds where it has been squeezed from
the flanks.
In the open pit, gyp.sum is found to a depth of 50 feet; below, it is
mixed with lenses and thin stringers of anhydrite that gradually in-
crease in thickness and quantity until the entire mass becomes anhy-
dritic. The anhydrite is very fine to fine grained, bluish ^ray to white,
becoming pink at the base, and includes traces of halite and other
soluble sodium salts.
192 MINERAL AND WATER RESOURCES OF CALIFORNIA
The original extent of the basin in which the gypsum was deposited
is unknown, as the gypsum is now in isohited erosional remnants
scattered over an area about 4 miles long and 2i/2 miles wide. The
largest deposit, a mass about 2 miles long and half a mile wide, is
being developed by the U.S. Gypsum Co. near the north end of the
exposures. In the Vallecito Mountains nortlnvest of the Fish Creek
Mountains (No. 8) , are other exposed deposits reported to be sufficient
to supply a gypsum plant "* * * for 100 years" (Rock Products,
1959b, p. 50).
About 1 mile north of the open pit of the U.S. Gypsum Co. and
separated from it by Fish Creek (No. 9) is an isolated outcrop of
gypsum (Durrell, 1953, p. 5-7), thin bedded and dark at the base,
grading upward to lighter and more massive rock.
A small gypsum deposit from which a limited amount of agricul-
tural gypsum has been produced is on the extreme eastern side of
the Fish Creek Mountains (No. 10). Other deposits include those
in the Coyote Mountains (Nos. 11 and 12) ,
Inyo County
Southeast of Tecopa at China Ranch in the Death Valley region
(No. 13), gypsum occurs in tilted lake beds of Pliocene(?) age (Ver
Planck, 1952, p. 38-39). The gypsum beds range from 6 inches to
3 feet in thickness separated by thin laminations of shale. The
gypsum is compact, white to light gray. Deposits at Black Mountain
(No. 14), Copper Canyon (No. 15), and Furnace Creek (No, 16) are
probably of early Pliocene age. They resemble the deposit at China
Lake, where some mining was done in 1916 and 1917.
Kern County
Kern County is the largest producer of gypsite in the United States.
In 1962 nearly three-quarters of all the gypsite produced in California,
about 855,000 tons, came from this county (Davis and others, 1963,
p. 202). The largest deposits are in the Lost Hills (No. 17), a low
northwest-trending range about 25 miles west of Wasco. The gypsite
occurs as flat-lying lenses, as much as 20 feet thick, of white, earthy,
soft, and powdery material overlain by 3 to 10 feet of sandy soil.
The major producer in the Lost Hills is H. M. Holloway, Inc., of
Wasco, California. In mining operations, drilling to determine the
extent of the deposit is followed by removal of overburden by scraper,
after which the gypsum is picked up by a mobile milling unit, which
screens the material and piles it into windrows. The materials, as much
as 3,000 tons daily, is sold by the truck load for soil conditioner in
three grades, 60, 65, and 70 percent gypsum.
Gypsite also occurs in the vicinity of McKittrick in the western part
of the county (No. 18), where it was formed in shallow basins by re-
sidual Aveathering of gypsiferous beds in the Monterey Shale and the
Tulare Formation (Ver Planck, 1952, p. 53). It is white on the sur-
face and gray at depth. Gypsite has been produced here intermittently
since 1900. In 1955, the Superior Gypsum Co. of Bakersfield opened
a deposit in the Bitterwater Creek area in the Temblor Range (No. 19)
(Rock Products, 1955, p. 102). Gypsite is also produced near Mari-
copa (No. 20) and Taft (No. 21) .
Other gypsite deposits are: at Kern Lake (No. 22), Koehn Lake
(No. 23), McClure Valley (No. 24) (Hess, 1920, p. 64-65) ; Blackwells
MINERAL AND WATER RESOURCES OF CALIFORNIA 193
Comer (No. 25) (Ver Planck, 1952, p. 123) ; Cottomvood Creek (No.
26), 16 miles east of Bakersfield (Hess, 1920, p. 70-71) ; Buena Vista
Lake, (No. 27) (Hess, 1920, p. 73) ; and Pioneer (No. 28) (Hess, 1920,
p. 70).
Gypsum occurs in Cuddy Canyon (No. 29) as thin lenses, inter-
bedded with sandstone (Ver Planck, 1952, p. 39^0) .
Kings County
Deposits of gypsite of playa lake origin are in the Avenal Gap and
Kettleman Hills area, southeast of Avenal. Those at Avenal Gap (No.
30) , average about 6 feet thick. The upper 2 feet consist of hard gray
silt with streaks and blebs of finely divided gypsum, the lower 4 feet of
fine-grained soft yellowish- white gypsite mixed with sand (Ver
Planck, 1952, p. 56-57). The deposits in the Kettleman Hills (No.
31) , similar to those at Avenal Gap, are being worked by the McPhaill
Gypsum Co. of Visalia.
Los Angeles County
Gypsite occurs at Palmdale (No. 32), derived from the gypsiferous
shales of the Escondido Formation. The deposits are exploited ex-
tensively from 1892 to about 1915 (Ver Planck, 1952, p. 57).
At Mint Canyon (No. 33), a gypsiferous zone as much as 15 feet
thick occurs in the Vasquez Formation. The gypsum is gray to brown,
in thin beds interbedded with coarse, angular, greenish sandstone.
Hess (1920, p. 75) reported the production of gypsite in 1904 and
1905 in Charley (Charles) Canyon (No. 34).
Merced Gov/nty
Gypsite was being produced in 1952 from the western foothills of
Merced County. The deposits are close to the surface and range from
6 inches to 6 feet iij; thickness (Davis and Carlson, 1952, p. 227-228).
This material, guaranteed to contain 30 percent gypsum (California
Bureau of Chemistry, 1954, p. 185), is produced by the Agricultural
Minerals and Fertilizer Co. of Los Banos, in the Ortigalita Creek area
(No. 35).
Another deposit occurs along the Los Banos Creek (No. 36) (Ver
Planck, 1952, p. 125).
Orange Cou/nty
W\ni^ fine-grained gypsum occurs in Gypsum Canyon on the west/-
ern slope of the Santa Ana Range (No. 37) (Hess, 1920, p. 77), in a
bed 8 to 10 feet thick that contains dolomite inclusions. Apparently
the gypsum-bearing rocks have been folded and gypsum thickened
locally by plastic flowage. A similar deposit of unknown extent has
been reported from Sycamore Canyon (No. 38) (Ver Planck, 1952,
p. 125).
Riverside County
In Riverside County gypsum occurs in the Little Maria, Maria,
Palen, and Riverside Mountains, and gypsite occurs in the foothills of
the Santa Ana Mountains near Corona. Only in the Little Maria
Mountains has there been extensive production.
The gypsum in the Little Maria Mountains is in an east-trending
belt 21/^ miles long to 1 and 2 miles wide that crosses the middle of the
194 MINERAL AND WATER RESOURCES OF CALIFORNIA
mountains. Gypsum is interbedded with shale, limestone, and gypsi-
ferous schists of the Maria Formation of "post-Cambrian" ao^e (Miller,
1944, p. 25) , and can tentatively be correlated with the gypsum-bearing
Kaibab Limestone of Permian age in southern Nevada and northwest-
ern Arizona.
Most of the gypsum on the western side of the mountains is asso-
ciated with buff limestone; minor amounts have been found with
schists. The sequences of gypsum-bearing rock are as much as 150
feet thick and are poorly exposed ; the surface is marked by a light-
gray soil. The gypsum is interbedded with green schist, quartzite, and
limestone, and generally is in masses too impure to exploit.
Coarse-grained white gypsum that averages about 93 percent pure
is exposed in the southern part of the mountains (No. 39). This
deposit was worked by open-pit methods by the Utah Construction Co.
from 1947 to 1950. The gypsum is in beds that range from 3 to 60
feet in thickness and are associated with green schist. The beds strike
N. 25° E. and have an average dip of 60° NW. Light-blue massive
anhydrite was exposed in the workimrs.
The gypsum in the eastern end of the belt has been extensively ex-
ploited west of the town of Midland by the U.S. Gypsum Co. Two
of the six beds of gypsum present are thick enough to be considered
economic ; the remaining beds are thin discontinuous lenses. Gypsum
crops out on the north edge of the belt (No. 40), and on the south
edge of the belt ( No. 41 ) .
The individual gypsum beds are faulted and folded into minor
flexures ; gypsum is thickest in the crests of the anticlines as the result
of plastic flowage from the flanks during folding.
Dense anhydrite, white to light blue gray, is found at depths of
30 to 100 feet below the surface. Near the anhydrite gypsum is
snow white and purer than at other places, suggesting that the waters
which liydrated the anhydrite also introduced some impurities.
Naturally-calcined anhydrite, formed by heat generated by move-
ment along faults in gypsum, occurs as white powdery gouge 2 to 4
feet wide.
The U.S. Gypsum Co. has been mining gypsum from these deposits
by open-pit and underground methods since 1925; at present only
open-pit methods are used- The material is blasted, loaded bv shovel
into tmcks for transport about 2% miles to the mill at Midland, where
it is crushed, ground in raymond mills, and calcined. The plant
produces plaster, lath, and wallboard. The capacity of the open pit
and mill is about 750 tons a day.
Gypsum occurs about 3% miles east of Midland, on the west slope
of tiie Maria Mountains (No. 42). The gypsum, in two beds sepa-
rated by limestone in a bluff 300 to 500 feet high, is probably equivalent
to that in the Little Maria Mountains (Tucker and Sampson, 1945,
p. 170-172). Some development work has been done, but no gypsum
has been produced. In 1957 this deposit was owned by the U.S.
Gypsum Co.
Gypsum in three isolated masses in an east-trending belt about 3
miles long and from % to li/^ miles wide occurs at the north end
of the Palen Mountains (No. 43 ) . Massive beds of white, fine-grained
gypsum are highly faulted and folded (Hoppin, 1954, p. 9).
MINERAL AND WATER RESOURCES OF CALIFORNIA 195
Gypsum occurs on the east side of the Riverside Mountains in the
northeast corner of the county, south of Vidal (No- 44) in the Colorado
River Indian Reservation. Deposits inchide the Parkford and the
Riverside gypsum deposits, both owned by the Indian Tribal Council.
The age of the gypsum is unknown, but is probably equivalent to the
Kaibab Limestone of Permian age. The gypsum in the Parkford
deposit, is massive, white, and interbedded with limestone (Tucker
and Sampson, 1945, p. 170). The individual beds, which crop out
in four north-trending hogbacks, are as much as 50 feet thick, and
dip 30° to 60° W. Some development work has been done, but no
production reported. Gypsite in beds as much as 10 feet thick occurs
below the outcrop.
The Riverside deposit is similar. The gypsum in beds alternating
with limestone, has an aggregate thickness of 70 feet and is traceable
along the outcrop for about 1,000 feet. Samples from this deposit
are reported to average 98 percent gypsum (Tucker and Sampson,
1945, p. 170).
South of Corona, in the extreme western edge of the coimty, gyp-
site occurs in the foothills of the Santa Ana Mountains, in a belt S^
miles long (No. 45) (Gray, 1961, p. 82-86). The gypsite is in Haga-
dor. Gypsum (Main Street) , and Eagle Canyons. The material assays
only 15 to 38 percent gypsum.
San Benito County
Gypsum has been reported in Bitterwater Valley (No. 46) , 10 miles
northeast of King City. The gypsum is in the Paso Robles Formation
in lenses 3 to 7 feet thick and as much as 900 feet wide. It is associ-
ated with beds of siltstone and light -gray sandstone (Ver Planck,
1952, p. 40) . Some gypsum has been produced for agricultural use,
but since 1949 tlie deposits have not been worked.
The Tully deposit (No. 47), on the eastern side of Bitterwater Val-
ley consists of beds and masses of gray to white gypsum mixed with
clay. A similar deposit from which some gj^psite was produced around
1906 is fomid just west of Hernandez (No. 48) (California State Min-
ing Bureau, 1906, p. 286-287).
A deposit of gypsite of unknown geologic setting Avas reported by
Ver Planck (1952, p. 127) at Silver Creek (No. 49).
San Bemardino County
At the south end of Death Valley in the Avawatz Mountains gyp-
sum is associated with salt and celestite in deformed Tertiary lacus-
trine beds. These beds are exposed in a northwest-trending belt about
10 miles long and 1 to 2 miles wide in the foothills on the north side of
the mountains (No. 50). Ver Planck (1952, p. 45-46) has described
the gypsum in five areas here.
Bristol Playa Lake covers an area of about 35 square miles (No. 51) .
Gypsum is present Avithin the playa both as dunes and as irregular beds
and isolated selenite crystals and plates as much as an inch long mostly
along the northwest border of the lake (Hess, 1920, p. 81-82). This
deposit was worked by open-pit methods from 1906 to 1924 (Ver
Planck, 1952, p. 47) and the gypsimi was shipped to a plaster mill at
the rail head at Amboy.
Danby Playa Lake (No. 52) , 14 miles long and 1 to 4 miles wide, has
deposits similar to those of Bristol Lake. Selenite crystals associated
196 MINERAL AND WATER RESOURCES OF CALIFORNIA
with clay and silt make up as much as one-third of the lake sediments,
and are concentrated along the northeast margins of the lake. Knobs
of selenite crystals mixed with clay stand as much as 10 feet above
the lake surface.
Gypsum occurs in the Clark Mountains in the northeast corner of
the comity near the Nevada State line (Ver Planck, 1952, p. 2-1-27)
(No. 53). White, sugary gypsum, in rocks that can be correlated
with the Kaibab Limestone of Permian age in Nevada, occurs in 4 or
5 beds or series of beds which crop out for about 2 miles along a dry
wash. These beds range from a few feet to as much as 50 feet in
thickness, strike N. 40° W., and dip about 50° SW.
The Red Canyon deposit (No. 54), is on the west-central part of
the Shadow Mountains about 12 miles north of Baker (Wright and
others, 1953). Gypsum is in lay ere a few inches thick in yellow
siltstone of Tertiary age. The largest exposed body is a 6-foot
sequence of thin beds of gypsum exposed for about 70 feet along strike.
Some prospecting has been done.
The Owl Hole Spring deposit (No. 55) is similar to the Avawatz
Mountain deposit (Ver Planck, 1952, p. 39). Thin beds of gypsum
and gypsiferous shale occur in Pliocene(?) lake beds which strike
east and dip north.
Deposits of unknown extent are reported from Field (No. 56) and
the Calico Mountains (No. 57) (Ver Planck, 1952, p. 128). The latter
was apparently worked briefly in 1916.
San Joaquin Goimiy
Selenite in veins near Vemalis (No. 58) has been reported by
Ver Planck (1952, p. 129). These occurrences are of mineralogic
interest only.
San Luis Ohispo County
Gypsite occurs in the Carrizo Plain (No. 59) in rocks of the
McKittrick Group of former usage (Jacalitos to Tulare interval)
along the margins of playa lakes. The deposits are essentially
elongate lenses, the largest about 1,500 feet long and as much as 4 feet
thick, of limy tan, sandy or earthy gypsite associated with fine-grained
gravels or gray silt. Deposits several miles east of Simmler (No. 60)
are Avorked by the Superior Gypsum Co. of Bakersfield, which pro-
duces material guaranteed to <*ontain at least 70 percent gypsum
(California Bureau of Chemistry, 1954, p. 187) .
Other deposits include: 1) tan limy gypsite at Shandon (No. 61)
(Ver Planck, 1952, p. 58-59), in a lens about 500 yards long and 200
yards wide on the mai-gin of a playa lake from which some mining
has been reported, and 2) lenticular masses of gypsum along Alamo
Creek (No. 62) and Arroyo Grande Creek (No. 63)..
Santa. Barbara Coimty
Gypsum at Point Sal (No. 64) occurred as nodules and veins in
shale of Miocene age. This deposit, mined from about 1880 to 1889,
was the fii-st important source of gypsum in the State (Ver Planck,
1962, p. 67).
Deposits in the Caliente Formation of Miocene to Pliocene age (Ver
Planck, 1952, p. 41) crop out in a northeast-trending belt about 7 miles
MINERAL AND WATER RESOURCES OF CALIFORNIA 197
long on the northeastern edge of the county in Cuyama Valley (No. 65)
and extend to Ventura County. The beds consist of interbedded dark-
brown shale, sandstone, and thin lenticular gypsum as much as 10
feet thick. The gypsum is white and alabaster in texture and contains
green shale laminae and lenses. In 1960, agricultural gypsite was
produced from a small deposit one-half mile south of Ventucopa; the
deposit is now exhausted.
Shasta County
Gypsum and anhydrite occur as large bunches or masses as gangue
minerals in the deeper levels in the Bully Hill and Rising Star copper-
zinc mines (No. 66), (Graton, 1910, p. 100, 103). Masses of gypsum
are commonly banded by inclusions of thin parallel films of sericitic
and chloritic material. Included in the calcium sulfate minerals are
finely disseminated crystals of pyrite. Graton believed that the anhy-
drite was introduced by ore-bearing solutions and later altered to
gypsum.
Ventura Ommty
Gypsum has been produced in Quatal Canyon, from 10- to 30-foot-
thick beds in the Santa Margarita Formation, which crops out at
irregular intervals for a distance of 7 miles in a northwest-trending
belt. On the northern edge of the belt (No. 67), on the north side of
Quatal Canyon, the Monolith Portland Cement Co. has produced
gypsum for cement retarder. Other deposits occur north and south
of Quatal Canyon (Ver Planck, 1952, p. 35).
At the south end of the belt of gypsum-bearing rocks, in Burges
Canyon, gypsum lenses as much as 10 feet thick are associated with
green shale. Extremely fine grained alabaster, notably at French
Point (No. 68), has been used locally for art objects.
Other gypsum deposits were reported from Ojai Valley (No. 69) ;
on the east flank of South Mountain, 4 miles south of Santa Paula,
(No. 70) ; and 4 miles south of Fillmore (No. 71) from which some
production was reported (Hess, 1920, p. 85).
Selected References
California Bureau Chemistry, 1954, Fertilizing materials : California Dept. Agr.
Spec. Pub. 255, 216 p. [1955].
California State Mining Bureau, 1906, The structural and industrial minerals
of California : California Mining Bur. Bull. 38, 412 p.
Davis, F. F., and Carlson, D. W., 1952, Mines and mineral resources of Merced
County [California] : California Jour. Mines and Geology, v. 48, p. 207-251.
Davis, L. E., Edgerton, C. D., Ashizawa, R. Y., and Giorgetti, L., 1963, The
mineral industry of California : U.S. Bur. Mines Minerals Yearbook 1962, v.
3, p. 159-225.
Durrell, Cordell, 1953, Geological investigations of strontium deposits in southern
California : California Div. Mines Spec. Rept. 32, 48 p.
Graton, L. C, 1910, The occurrence of copper in Shasta County, California :
U.S. Geol. Survey Bull. 430, p. 71-111.
Gray, C. H., Jr., 1961, Mines and mineral deposits of the Corona South quad-
rangle. Riverside and Orange Counties, California : California Div. Mines
Bull. 178, p. 59-120.
Hess, F. L., 1920, California, in Gypsum deposits of the United States: U.S.
Geol. Survey Bull. 697, p. 58-86.
Hoppin, R. A., 1954, Geology of the Palen Mountains gypsum deposit. Riverside
County, California : California Div. Mines Spec. Rept. 36, 25 p.
198 MINERAL AND WATER RESOURCES OF CALIFORNIA
Miller, W. J., 1944, Geology of Palm Spring-Blythe Strip, Riverside County,
California : California Jour. Mines and Geology, v. 40, p. 11-72.
Rock Products, 1955, Gypsum plant in full scale operation : Rock Products, v.
58, no. 10, p. 102.
, 1959a, New plants dot industries horizon : Rock Products, v. 62, no. 11,
p. 58.
-, 1959b, National Gypsum dedicates Waukegan plant, plans others : Rock
Products, V. 62. no. 11, p. 50.
Sharp, R. P., 1935, Geology of Ravenna quadrangle, California [abs.] : Pan-
American Geologist, V. 63, no. 4, p. 314 ; Geol. Soc. America Proc. 1935, p. 336
(1936).
Tucker, W. B., and Sampson, R. J., 1945, Mineral resources of Riverside County
[California] : California Jour. Mines and Geology, v. 41, no. 3, p. 121-182.
Ver Planck, W. E., Jr., 1952, Gypsum in California : California Div. Mines Bull.
163, 151 p.
Wright, L. A., Stewart, R. M., Gay. T. E., Jr., and Hazenbush, G. C, 1953, Mines
and mineral deposits of San Bernardino County, California : California Jour.
Mines and Geology, v. 49, nos. 1-2, p. 49-259 [plus 192 p. tabulated list of
mines and mineral deposits in San Bernardino County].
IODINE
(By G. I. Smith, U.S. Geological Survey, Menlo Park, Calif.)
Iodine is produced in the United States from well brines. Plants
operated by the Dow Chemical Co. in Michigan and California furnish
the entire domestic output, and this satisfies a large part of United
States requirements (Miller, 1964; Stipp, 1960).
Most iodine is first produced in crude form (at least 99 percent
pure), but before use is either resublimed to a purer elemental form
or converted to potassium iodide or other inorganic or organic com-
pounds. Its uses are many. Iodine and its salts are used as antiseptics
and for other medical purposes, as additives to food for both humans
and animals, as components of photographic emulsions, and for sani-
tation, metal production, and other specialized chemical uses. The
isotope iodine-131 is used as a tracer for industrial and research pur-
poses. Consumption of iodine in the United States has increased
steadily ; in 1963 it was 8 percent higher than in 1962, and more than
twice that of 1953. The current price of crude iodine in kegs is $1.18
per pound (Miller, 1964).
In the early 18()0's, iodine was produced in Europe from seaweeds ;
these plants concentrate iodine from sea water, and, after treatment,
some seaweed residues contain as much as 1.8 percent iodine. In the
late 1860's, production of iodine as a by-product of the Chilean nitrate
industry began, and that source dominated world supply for over a
half a century. In 1928, production from brines began in Louisiana^
and by 1932, production from California brines became the major
domestic source. Similar sources were developed at about the same
time in Kussia, Germany, France, and England (Reiser, 1960; Ver
Planck, 1957 ; Stipp, 1960 ; Miller, 1964) .
Iodine production in California started in 1932 at a plant at Long
Beach operated by the General Salt Co. Shortly thereafter, a plant
operated by the Deepwater Chemical Co., Ltd., was started at Comp-
ton, and the Dow Chemical Co. started extraction operations at Seal
Beach, Venice, and Inglewood. All use brines that accompany the oil
pumped to the surface in oil wells. Several fields produce brines con-
MINERAL AND WATER RESOURCES OF CALIFORNIA 199
tainin^ abnormal quantities of iodine, but only those at Dominguez,
Playa del Rey, Inglewood, Seal Beach, and Long Beach contain recov-
erable amounts. These brines average 2i/2 to 3 percent total solids and
contain an average of about 50 ppm iodine (Ver Planck, 1957). Only
the Dow Chemical Co. plant at Seal Beach is still in operation, and
production is currently being transferred from that plant to Michigan
(Miller, 1964).
No other economic sources of iodine are known in California.
Shh^ected References
Keiser, H. D., 1960, Minor industrial minerals, in Industrial minerals and rocks :
New York. Am. Inst. Mining Metall. Petroleum Engineers, p. 605-621.
Miller, W. C, 1964, Iodine: U.S. Bur. Mines, Minerals Yearbook, 1963, v. 1,
p. 595-599.
Stipp, H. E., 1960, Iodine, in Mineral facts and problems : U.S. Bur. Mines Bull.
585 p. 473—479.
Ver Planck, W. E., 1957, Iodine : California Div. Mines Bull. 176, p. 241-243.
IRON
(By Lyman Moore, U.S. Bureau of Mines, San Francisco, Calif.)
Importance and Use
Iron ore is the basic raw material for iron and steel, the foundation
of industrialized civilization; in tonnage, over 90 percent of all metal
consumed in the United States is iron or steel.
Iron in a relatively pure state, such as wrought iron, is a tough
malleable inexpensive metal. Sfeel is a mixture (alloy) of iron and
carbon. The term alloy steel is used to describe mixtures of steel and
other elements such as tungsten, nickel, vanadium, and many others.
By varying the carbon content, heat treatment, and forming methods,
steels can be made having a wide range of physical properties. Prop-
erties range from those of low carbon steel with moderate yield
strengths and the ductility required to allow cheap mass production
by pressing and stamping, to spring steels having high yield strengths.
Engineering, tool, razor, stainless, and other specialized steels possess
extreme strength, hardness, toughness, resistance to corrosion and
heat softening, and other desirable properties. The relatively low
price of steel, along with its versatility, makes it the indispensible
metal in our economy. The principal users in the United States, in
decreasing order of importance are: 1) automotive, 19 percent of the
total consumption; 2) construction, 17 percent; 3) containers, 8 per-
cent; 4) oil and gas industry, 7 percent; 5) industrial machinery,
6 percent; 6) rail transport, 6 percent; 7) electrical machinery, 3
percent; 8) appliances, 3 percent; and 9) agricultural, 2 percent.
Geologic Occurrence
Iron is an abundant metal, comprising about 5 percent of the earth's
crust. Iron ore deposits are widely distributed throughout the world,
and are estimated to contain over 70,000 million tons of iron ore.
Under present economic conditions, only ore bodies located conveni-
ently to steel markets and sources of coking coal or deposits either of
200 MINERAL AND WATER RESOURCES OF CALIFORNIA
iiniisual size and orade or particularly adapted to low-cost produc-
tion can be utilized.
A variety of geologic processes have formed the iron concentra-
tions whicli supply the world's industry. The most prominent, known
as the Lahe. Superior ty])e, occurs in northern Minnesota, Wisconsin,
and Michigan, and in Labrador, Venezuela, Brazil, Russia, South
Africa, India, Australia, and China. These deposits were formed in
Precambrian time through the selective leaching of meteoric waters
of thick sedimentary iron formation called taconites. Taconites con-
sist of banded or irregularly intermingled chert and ferric oxide.
Technologic advancements have made it profitable to utilize portions
of the iron formation itself.
Sedimentary iron ores, although generally low grade, have been
of great past importance, partly because of their frequent geographical
proximity to coal measures. However, recent reductions in world
iron ore prices, brought about by improved mining and processing
methods and cheaper transportation, have reduced production from
these deposits. The most important sedimentary iron ore districts
have been Birmingham, Ala.; Lorraine, France; Luxembourg; and
Yorkshire, England. The ores oc^'ur in well-defined sedimentary beds
and have a wide regional extent. In some locations the beds are as
thick as 40 feet, but they rarely exceed 12 feet. Hematite, limonite,
or siderite may be the predominant iron mineral and the ores usually
have an oolitic structure.
Kirimrr-type deposits, mainly magnetite with considerable apatite,
occur in northern Sweden. They conunonly are tabular and were
fonned by processes of fractional crystallization and injection sim-
ilar to those that result in the intrusion of igneous dikes.
Contact metamorphic deposits are common throughout the world
and many examples are known in the western United States, includ-
ing California. These deposits are formed at high temperatures in
limestone or dolomite beds at their contact with intrusive rocks.
Magnetite is the principal iron mineral and a gangue of garnet and
other lime and magnesium silicates is characteristic. Contact deposits
are not formed in chemically inert rocks and in these the mineralizing
solutions proceed some distance from the source and deposition takes
place as the solutions cool. These deposits are referred to as hydro-
ihermal and are a type of deep-seated vein deposit. Replaceinent
deposits are formed in limestone or other rocks.
History and Production
Tlie first iron works in the United States was built near Jamestown.
Va., in 1620 and the first steel was made in 1728 at Hartford, Conn.
Modern United States steel numufacture began with the first pour
of Bessemer steel in 1864, followed by the first open-hearth steel in
1868. The 1860 census reported United States production of 3.2 mil-
lion long tons of iron ore, slightly less than 1 million short tons of
pig iron, and only 11,838 short tons of steel. By 1900, United States
production was 27.5 million long tons of iron ore, 13.8 million short
tons of pig iron (34 percent of world output). In 1963, production
was 73.6 million long tons of iron ore, 71.8 million short tons of pig
iron (23 percent of world output), and 75.6 million short tons of
MINERAL AND WATER RESOURCES OF CALIFORNIA 201
finished steel (26 percent of world output). The United States has
been the world's largest producer of iron and steel since 1897.
Only small quantities of iron ore were produced in California be-
fore World "War II, Foundries and rolling mills have been active
in the State since the pioneer period and the first open hearth was
built in 1884. The steel furnaces were charged with scrap and im-
ported pig iron; the rolling and finishing mills used imported ingots
and coils as well as ingots cast locally. No blast furnaces were in
operation. Production of pig iron in California was hampered by a
lack of coking coal, which had to be shipped in from tlic Rocky Moun-
tain or Appalachian fields; by the small size of the market, which
prevented the use of more efficient large-sized furnaces; and by low
shipping rates, as ballast for steel imports.
California's primary iron and steel production has grown rapidly
since Kaiser Steel Corp. built a blast furnace in 1942 at Fontana. Al-
though there is still only the one primary plant in the State, pig-iron
capacity has been increased from about 400,000 short, tons in 1942 to
almost 2 million tons in 1960. This capacity is still only a little over
2 percent of United States capacity whereas California has 10 percent
of the nation's population. Thus, continued growth of the industry
within the State seems probable.
Present blast furnace capacity requires about 3.2 million long tons
of iron ore containing 60 percent Fe. An export market for iron ore
with Japanese steelmakers has developed since 1950 and contracts in
force in 1964 provide for the shipment of 1 million long tons per year
from mines within the State. Other California uses of iron ore are
as lump in open-hearth steelmaking, as an ingredient in low-heat port-
land cement, as heavy aggregate for ballast and nuclear shielding, as
a pigment, as a fluxing agent, and miscellaneous uses. These other uses
require about 200,000 long tons of iron ore per year.
Iron ore production statistics for California have not been published
since 1956. It is believed that in recent years blast furnaces have been
operating at near capacity and that iron ore has been exported at
somewhat above published contract levels. Thus, overall production
is about 4.4 million long tons of 60 percent iron ore per year. This is
about 3 percent of the United States total and places California sixth
among the producing states.
Occurrences in California
The important iron occurrences in California are shown on figure
31 and basic information concerning each deposit is given in table 22.
Geographically, California's iron deposits are concentrated in the
Mojave Desert province in western San Bernardino and Riverside
Counties. About 99 percent of the State's production has come from
this area. The area contains over 90 percent of the State's known
resources. All of the Moiave deposits are of igneous origin and differ
mainly in the kind of wall rock present and its consequent effect upon
the type of deposit formed. Contact metamorphic deposits, the area's
most prominent type, are formed at high temperatures in limestone
or dolomite at their contact with intrusive rock. The Eagle Moun
tain and Lava Bed deposits are of this type. They are characterized
by magnetite replacement and a gangue of contact silicates such as
67-164 O— 66^— pt. I 14
202
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA
205
124°
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TRINITY
^MOUNTAII
■ PLUMAS
EX PLAN* T ION
9 Vary Isrge; mora than 10,000,000 tons
(production plus published rasarvas)
O Large: betiiaen 10.000.000 and
I ,000,000 tons
• Medium: between t. 000, 000 and
100.000 tons
A Small: less than 100.000 tons
Numbers refer to table in text
°— I— ) "Jj LAKE ; 1
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Figure 31. Iron ore in California (numbers refer to table 22).
garnet, epidote, and pyroxene. Other deposits, such as the Vulcan,
show similar structural relationships but rock alteration processes
were less intense. Some deposits are of the hydrothermal replacement
and vein-filling type. An example is the Iron Age, where magnetite
occurs as veins in granite some distance from any apparent source of
ore-depositing solutions.
Other iron-ore deposits occur in the Sierra Nevada province, par-
ticularly in Western Madera County. The Minarets is the most im-
portant and is a hydrothermal replacement in dacite. Western Shasta
County, in the Klamath Mountain province, contains contact meta-
morphic magnetite deposits. A small sedimentary limonite deposit
206 MINERAL AND WATER RESOURCES OF CALIFORNIA
occurs in San Luis Obispo County and some production has come from
beach sands in Santa Cruz County. The State's most prominent iron-
ore deposits are described below.
Eagle Mountain district
Most of California's iron-ore production has come from the Eao;le
Mountain district (No. 68, fif^. 31) in Riverside County, 60 miles east
of Indio. Deposits occur throuo:hout a belt that extends 7 miles east-
west and has a width of about 1 mile. Past production has been
mostly from larg-e ore bodies at the eastern end of the belt. Kaiser
Steel Corp. is the only producer and owns most of the district's mineral
rights. Most of the blast furnace feed for Kaiser's Fontana steel mill,
plus the ore needed to satisfy a 1 million-ton-per-year export contract
is obtained from the Ea^^le Mountain mine.
The mineralized area is underlain by a series of quartzites and dolo-
mites which have been folded into a broad anticline that locally is
closely folded and faulted. Large elongate bodies of quartz mon-
zonite have intruded the sediments with the development of calcium
magnesium silicates in the dolomite and with heavy iron mineraliza-
tion, particularly in two dolomite beds. The ore deposits are roughly
tabular in shape conforming to the distribution of the dolomite. Indi-
vidual ore bodies extend for as much as 3,000 feet along the strike
and have been developed to a depth of 1,000 feet on a dip of 45°. The
ore width being mined consists of a footwall ore bed 40 to 140 feet in
width and a hanging-wall ore bed 30 to 300 feet in width. The two
beds are separated by 200 to 300 feet of barren quartzite.
The primary ore is magnetite but throughout a thick zone of oxida-
tion it has been partially weathered to liematite. The ore ranges from
40 to 50 percent Fe and is beneficiated before use. Sulfur, the only
contaminant, is low enough in the oxidized ore to permit use without
further treatment. In the primary ore, sulfur content is reduced by
sintering or pelletizing.
Kaiser Steel Corp. has estimated that 108,675,000 long tons of ore
containing 45.2 percent Fe can be mined profitably at 1965 prices from
the present open pit. No estimate has been published of resources in
the remainder of the district.
Lava Bed dv^trict
The Lava Bed district, 30 miles northeast of Lucerne Valley, has
produced over 50,000 long tons of direct shipping iron ore from the
Bessemer, Morris Lode, and Ebony properties. Extensive explora-
tion has been done on the Bessemer, Morris Lode, and Cat-Man-Ord
properties.
Bessemer. — Production from this property (No. 52, fig. 31) totaled
28,000 tons from 1945 to 1951. The Bessemer deposit consists of
replacements of magnetite in dolomite along an irregular contact with
granite. The mineralized dolomite occurs as remnants, now engulfed
in granite, or as points of dolomite surrounded on three sides by the
intrusive. The largest ore body covers an area of about 50,000 square
feet and has been mined by open pit. In the deposit medium-width
veins of high-grade ore are interspersed with barren or selectively
replaced beds of dolomite. Fourteen small ore bodies crop out in the
area and additional bodies were found under nearby alluvium by mag-
MINERAL AND WATER RESOURCES OF CALIFORNIA 207
iietite prospecting and drilling (Wright, 1953, p. 86-100). The de-
posit was estimated to contain 1.8 million tons of ;^0 to 65 percent Fe
ore of which 240,000 tons contained between 60 and 65 percent Fe
(Calif. Div. Mines Bnll. 129).
Morris Lode.—T\\^ Morris Lode (No. 54, fig. 31) produced 17,500
tons in 1949-1950 for use in cement manufacture and a few thousand
tons of lump ore in 1957. The mineralized area is underlain by
dolomitic limestone intruded by granitic rocks. Large skarn areas
were formed in the dolomite along the granite contact. Two types
of ore occurrences are present: (1) Small irregular bodies of high-
grade ore are found along the dolomite-granite contact, often coni-
pletely replacing small inclusions of dolomite, and (2) a large deposit
of medium- and low-grade ore is found in a skarn zone adjacent to
the contact. In 1944-1945, a magnetic anomaly 1,000 feet wide and
1,500 feet long was delineated. Subsequent drilling revealed an ore
body with an area of about 10 acres. Eight drill holes intersected
from 120 to 921 feet of iron ore with an average grade of 37.32
percent Fe. Two holes drilled in a zone of lower magnetic intensity
surrounding this area intersected from 100 to 400 feet of material
with more than 15 percent Fe ( Wiebelt, 1947) .
Magnetite is the predominant ore mineral but some primary he-
matite is found at depth and somewhat earthy secondary hematite
and limonite occur near the surface. The ore has about 2 percent
sulfur in the form of pyrite, but phosphorus and other impurities
are low.
Baxter' district
The Baxter district is about 16 miles west of Baker, and immediately
north of the Mojave River. Although no production figures have
been published the Cave Canyon mine has had moderate production,
and small production has come from the Cronese and Cave Mountain
properties. Shipments were made from 1934 to 1957. The iron ore
was used almost entirely in the manufacture of low-heat portland
cement.
Cave Canyon mine. — The area containing this deposit (No. 37, fig.
31 ) is underlain by Precambrian gneiss and quartzite, by a later Pre-
cambrian limestone, and by Tertiary sandstone and f anglomerate. In-
trusive into the Precambrian rocks is a diorite porphyry to which
the iron mineralization is related. The ore area is intensely brecciated
by faulting and folding. The iron ore occurs as a replacement of
the Precambrian rocks and the pi-evalence of remnants of unreplaced
limestone in the ore zone indicates that this rock was most susceptible
to mineralization. In places, quartzite also is mineralized and grades
into ore. The iron was deposited as magnetite but has been oxidized
to about one-half hematite. Some gypsum is present.
Reserves were estimated in 1944 as 4,105,000 long tons, of which
only 1,350,000 long tons was recoverable at 1944 prices. Because
of the intense brecciation, much dilution of the ore is inevitable during
mining, and beneficiation would be required to make a high-grade
product.
Providence district
The Providence district is on the west slope of the Providence Moun-
tains in San Bernardino County about 9 miles southeast of Kelso.
208 MINERAL AND WATER RESOURCES OF CALIFORNIA
All of the district's production has come from the Vulcan mine (No.
43, fig. 31), which provided the primary source of iron ore for the
Fontana steel plant during World War II. It produced 2,643,000
long tons in the period from 1942 when the mine was opened, to
1947 when demand Avas shifted to the Eagle Mountain mine. Sub-
sequent production has consisted only of moderate quantities of lump
ore and ore for use in low-heat portland cement manufacture.
The Vulcan area is imderlain by marine sedimentary rocks ranging
in age from Cambrian to Jurassic which were intruded by quartz
monzonite in Jurassic time and which were later intruded and partly
covered by Tertiary rhyolite. The iron-ore deposit occurs as a mush-
room-shaped replacement in marbleized Cambrian limestone adjacent
to quartz monzonite whose contact with the limestone and ore is a
fault plane. x4.t the surface the ore body was 700 feet long and 325
feet wide, but at depth the deposit decreased in horizontal cross section
and became pipe shaped. The ore has been intersected to a depth of
900 feet in drill holes. Hard, dark magnetite is the primary ore
mineral. A small amount of hematite, which decreases at depth, is
present. Sulfur, occurring in pyrite, is prominent in the primary ore
and is the only impurity of consequence. Weathering removed the
sulfur from the upper 50 feet of the deposit.
The property was estimated in 1944 to contain 5,680,000 long tons
of plus 50 percent Fe in the main ore body and additional ore in the
south ore body. After consideration of ore mined subsequent to 1944
and after including the south ore body, reserves are estimated at
5,520,000 long tons.
Silver Lake district
The Silver Lake district is in San Bernardino County, about 13
miles northwest of Baker. All of the production has come from the
Iron Mountain property which contains most of the district's re-
sources. The adjoining Iron King is a small deposit similar in
character to the Iron Mountain.
Iron Maunfam rnin-e. — Moderate quantities of ore were shipped by
Kaiser Steel Corp. to its Fontana plant from this property (No. 29,
fig. 31) during 1953 and from 1962 to 1964. The district was explored
by the U.S. Geological Survey in 1943 and 1944, and in 1944, the U.S.
Bureau of Mines drilled 12 holes on the property.
The ore-bearing formation is an extensive breccia over 200 feet
thick consisting predominately of broken limestone but containing
lenses composed of fragments of igneous and contact-metamorphic
rocks and of iron ore. Individual lenses are chiefly of one type of
rock. The breccia is underlain by sandstone and conglomerate and in
the mine area is overlain only by alluvium. A few hundred feet south
of the iron-ore deposits the sediments are in fault contact with
andesite that has l)een intruded by quartz monzonite. However, no
igneous rocks are known to intrude the sedimentary series containing
the iron-ore breccia.
Iron occurs as lenses of both solid massive magnetite and of breccia
ore. In addition to iron oxide, the latter ore contains fragments of
contact-metamorphic rock and partly replaced limestone. The ore
lenses are conformable to the limestone breccia and dip at angles of
20 to 35° with the long dimension of the oreshoots extending down
MINERAL AND WATER RESOURCES OF CALIFORNIA 209
the dip. Magnetite is the predominant iron ore mineral; a small
amount of secondary hematite also is present. The ore is low in sulfur
and phosphorus. Opinions differ as to the origin of the deposit ; some
geologists consider it a contact-metamorphic deposit that has been
shattered by faulting; others consider it to be a product of coarse
weathering of a now completely eroded iron-ore deposit ; and it is not
unreasonable to consider it a hj^drothermal deposit derived from the
quartz monzonite or from an unexposed igneous source.
Ore resen^es as established by Bureau of Mines drilling in 1944
were 6,175,000 long tons of material containing 54 percent Fe.
Kingston district
The Kingston district (No. 27, fig. 31) is in northeastern San Ber-
nardino County, 20 miles east of Tecopa. All of the ore, except for
some small prospects, occurs in the Beck deposit in a single geologic
horizon. The substantial size of the deposit was proven in 1924 when
14 holes were diamond drilled. However, only small quantities have
been mined and shipped for test work, chiefly because of high trans-
portation costs.
Magnetite occurs as the replacement of a 100-foot-thick white crys-
talline limestone bed in a Precambrian series of quartzite, dolomite, and
limestone. A thick sill of amphibolite of uncertain age occurs imme-
diately below the limestone. Along the limestone-amphibolite contact,
iron ore replacements occur in the footwall of the limestone bed. In
places the iron mineralization occurs across the full thickness of the
limestone and extends into the igneous rock. The deposits dip steeply
and are cut off at a depth of several hundred feet by a nearly horizontal
post-ore tlirust fault. The iron-ore deposits are thought to have been
formed by hydrothermal processes from solutions emanating from a
large body of quartz monzonite of Tertiary age that occurs south of
the deposits.
Iron mineralization occurs for over 1 mile along the limestone-
amphibolite contact and two main ore bodies are present. The west-
ern deposit is 1,100 feet long, has a maximum width of 140 feet, and
has been intercepted by drilling at 600 feet below the outcrop. The
eastern ore body is 1.100 feet long, 30 to 60 feet wide, and was inter-
cepted by drilling 250 feet below the outcrop. A split and a smaller
oreshoot 200 feet farther east are also considered part of the eastern
ore body. Massive magnetite and hematite make up the bulk of the
deposit, but the ore carries inclusions of quartz and calcite and patches
of unreplaced limestone and dolomite as well as various silicates of
iron, calcium, and magnesium. Pyrite is common and the sulfur con-
tent of the ore is about 0.40 percent ; phosphorus is low.
No recent estimate of ore reserves is available. In U.S. Geological
Surve}' Bulletin 871, published in 1936, reserves were estimated at 12
million long tons. The average grade of the ore is about 56 percent
Fe.
Dale district
The Dale district is in San Bernardino County, 25 miles east of
Twentynine Palms. Production to the end of 1963 was about 273,000
long tons of lump ore and concentrate. Except for several hundred
tons, production has come from the Iron Age mine and almost all of
210 MINERAL AND WATER RESOURCES OF CALIFORNIA
the district's reserves are in the downward extension of the Iron Age
deposit.
Iron Age mine. — The property (No. 60, fig. 31) was patented in
1902, but only about 11,000 tons was produced before 1956. A con-
centrating plant was installed in 1956.
The ore occurs in numerous steeply dipping, parallel replacement
veins in porphyritic granite. The largest oreshoot is 15 to 100 feet
wide and about 400 feet long. The other veins are much narrower.
Persistence of the mineralization in depth has been established by
drilling. The deposit is of the hydrothermal type. Dense magnetite,
which has been oxidized to hematite near the surface, constitutes the
bulk of the ore body. The ore is high grade, with very low sulfur,
phosphorus, and other impurities.
Minarets deposit
The Minarets deposit (No. 13, fig. 31) is 69 miles northeast of Fresno
in western Madera County, an alpine area inaccessible to motor ve-
hicles. It has been known since the 1860's but its isolated location has
discouraged exploration. The deposit was tested in 1944 and 1945
with surface sampling and two diamond drill holes.
The mineralized area is underlain by a slightly metamorphosed
sequence of dacite and andesite flows which are the host for the iron
deposition. Granite crops out nearby but it is clearly older than the
mineralization, which is apparently derived from a deeply buried
source. The main ore body is an elongated lens composed of somewhat
irregular layers of magnetite, or magnetite and actinolite, which are
completely enclosed within the volcanic series and seemingly have
replaced it. The magnetite is distributed throughout the ore body as
a series of sheets in which the proportions of magnetite and actinolite
vary gradationally. The sheets or layers are roughly parallel to the
trend of the ore body. The area of good-grade ore, in which the host
rock is mainly replaced by magnetite and actinolite, is surrounded by
an irregular zone in which the magnetite content grades from ore to
waste. The iron values consist mainly of magnetite with a gangue of
actinolite and minor feldspar and chlorite. Phosphorus ranges from
0.30 percent to 0.80 percent. The ore contains no other contaminants.
An ore body 1,500 feet long and 15 to 175 feet wide is exposed on the
surface. It was cut at depths of 250 and 300 feet by two drill holes.
In 1944 the deposit was estimated to contain 5 million tons of indicated
and inferred ore with a grade of 60 percent Fe and 2 million tons of
material containing 25 percent Fe. Bureau of Mines sampling and
drilling indicated that the deposit was of lower grade but that the
ore tonnage was larger (Severy, 1946) .
Shasta and California deposit
The iron-bearing area (No. 2, fig. 31) is on the east side of Shasta
Reservoir in Shasta County, about 12 air miles north of Redding. Iron
ore has been produced intermittently since 1892 Avhen it was used as a
smelter flux. About 15,000 tons was mined from 1907 to 1918 for use
in a nearby electric smelting plant and from 1942 to 1945 about 300,000
tons was sold for use as ship ballast. During 1944 the Bureau of
Mines drilled and sampled tlie deposit and made beneficiation tests.
Iron-ore deposits occur in an irregular contact-metamorphic zone
2,000 feet long and 300 to 1,000 feet wide formed in the Permian
McCloud Limestone along its contact with intrusive quartz diorite.
MINERAL AND WATER RESOURCES OF CALIFORNIA 211
The contact zone contains large proportions of garnet and epidote
along with small or localized occurrences of pyroxene, clilorite, and
serpentine. Irregular masses and pods of magnetite are intercalated
within the skarn and additional magnetite is disseminated throughout
the skarn. Individual pods range in size from a few tons to 25,000
tons or more. Two areas, one about 250 feet in diameter, and the other
100 feet in diameter, contain concentrations of large magnetite masses
and have an overall grade of about 40 percent Fe. Both of these areas
have been proven to a depth of over 500 feet by drilling. These areas
have been mined selectively. The ore contains magnetite with varying
proportions of garnet, epidote, and other contact minerals, 0.17 percent
sulfur, and minor phosphorus, and other impurities.
The Shasta and California iron-ore deposits were estimated in 1945
to contain 4,680,000 long tons of ore with an average grade of 37.82
percent Fe, above a depth of 500 feet.
Resource Potential
Known iron ore deposits in California were inventoried by the U.S.
Bureau of Mines in 1964. These deposits were estimated to contain a
total of 972 million long tons of ore with an average grade of 42 per-
cent Fe. Approximately one-half of this ore was classed as proven or
indicated and one-half was inferred on the basis of geomagnetic or
other information. It was further estimated — after considering the
stripping required or the mining difficulty expected, the anticipated
beneficiation expense, and transportation costs — that the following
quantities of 65 percent Fe pellets could be made from this material
at the indicated price levels with delivery in Los Angeles or San
Francisco :
Amount of 65 percent Fe pellets producible (cumulative totals)
Price : Long tons
$15.00 271, 000, 000
$20.00 430, 000, 000
$25.00 571, 000, 000
In preparing these estimates, the Bureau of Mines engineers assumed
neighboring deposits could be combined and operated as a unit to se-
cure lower operating costs and that processing losses could be limited
to 10 percent.
The present poste<l price for California iron pellets delivered in
Japanese steel centers is $16.25 per long ton of 64 percent grade. Con-
tracts i^rovide for delivery of 1.8 million tons per year from 1966 until
1974. This is equivalent to a price of $12.35 at Los Angeles or San
Francisco and well under the $15.00 price used in the above estimate.
As exploitation of deposits progresses, it is likely that total resource
figures will be expanded considerably.
Iron ore resists erosion and iron oxides have distinctive colors and
are high in specific gravity, so surface accumulations are easily recog-
nized. In addition, magnetite, a major iron mineral, is the easiest of
all minerals to find by geophysical prospecting methods. For these
reasons, it is probable that a greater proportion of the nation's iron
occurrences have been discovered than is the case for other commodi-
ties. Nearly all of California's known surface deposits were described
in reports dated prior to 1915. During the 1950's, private industry
undertook extensive airborne geomagnetic prospecting throughout the
212 MINERAL AND WATER RESOURCES OF CALIFORNIA
State's iron districts, spurred by the rapid o^rowth of demand for steel
on the Pacific Coast. Tliis exploration, while it failed to find any new
districts, resulted in the discovery of many additional ore bodies in
previously known areas and indicated that large resources of iron ore
were present in California.
Additional g;eoma2:netic surveys will find new ore bodies, but the
rate of future discoveries is certain to be much lower than in the past.
Obviously, the most promising- areas for exploration are in the Mojave
Desert and Klamath Mountains regions where previously examined
districts will be surveyed for deep-lying ore bodies and areas between
districts will be prospected for completely buried deposits.
Selected References
California Division of Mines, 1{>48, Iron resources of California : California Div.
Mines Bull. 129, 265 p.
, 1957, Mineral commodities of California : California Jour. Mines and
Geology Bull. 176, 736 p.
Carlson. D. W., and Clark. W. B.. 1954, Mines and mineral resources of Amador
County, California : California Jour. Mines and Geology, v. 50, no. 1, p. 200-201.
Franke, H. A., 1935, Mines and mineral resources of San Luis Obispo County.
California : California Jour. Mines and Geology, v. 31, no. 4, p. 423-425.
Harder. E. C. 1909, Some iron ores of western and central California : U.S. Geol.
Survey Bull. 430, p. 225-227.
Hubbard, H. G., 1943. Mines and mineral resources of Santa Cruz County,
California : California Jour. Mines and Geology, v. 39, no. 1, p. 35-36. 42-43.
, 1950, Mines and mineral resources of Madera County, California : Cali-
fornia Jour. Mines and Geology, v. 46, no. 4, p. 458.
Norman, L. A., Jr., and Stewart, R. R., 1951, Mines and mineral resources of
Inyo County, California : California Jour. Mines and Geology, v. 47. no. 1,
p. 54.
Saul, R. B., Gray, C H., and Evans, J. R., (19 ), Mines and mineral resources
of Riverside County, California: California Jour. Mines and Geology. (In
press)
Severy, C. L., 1M6, Exploration of the Minarets Iron Deposit, Madera County.
California : U.S. Bur. Mines Rept. Inv. 3,985. 12 p.
, 1948, Mining methods at the Yulcan iron mine, San Bernardino County,
California : U.S. Bur. Mines Inf. Circ. 7.437. 11 p.
Shattuck, .7. R. and Ricker, Spangler, 1948, Shasta and California iron-ore
deposits, Shasta County California : U.S. Bur. Mines Rept. Inv. 4,272. 11 p.
Wiebelt, F. J.. 1947, Bessemer iron project, San Bernardino County. California :
U.S. Bur. Mines Rept. Inv. 4,066, 13 p.
. 1948. Iron Mountain deposits, San Bernardino County, California :
U.S. Bur. Mines Rept. Inv. 4,236, 11 p.
Wright, L. A.. 1953, Mines and mineral deposits of San Bernardino County,
California : California Jour. Mines and Geology, v. 49, nos. 1 and 2, p. 86-100.
KYANITE, ANDALUSITE, AND RELATED MINERALS
(By G. H. Espenshade, U.S. Geological Survey, Washington, D.C.)
Industrl\l Use
Kyanite and andalusite are aluminum silicate minerals that were
once mined in California for the manufacture of refractory materials
with high-alumina content. Related minerals of similar composi-
tion— sillimanite, dumortierite, and topaz — can be used for the same
purposes and are also known to occur in California, but have not been
mined here. These minerals are commonly known as the sillimanite
group (also as the kyanite group), and are used to manufacture re-
MINERAL AND WATER RESOURCES OF CALIFORNIA
213
fractory materials that will withstand high temperatures and abrupt
temperature changes such as occur in metallurgical and glass fur-
naces and certain tyi^s of kilns and boilers. "V^Hien heated to high
temperatures these minerals all convert to the compound mullite
(3 AI2O3.2 Si02) and silica; refractories made from these materials
are commonly known as mullite refractories. Mullite can also be made
using other high-alumina materials, such as diaspore clay, bauxite,
and alumina, provided the content of iron and other impurities is low;
this type of mullite is known in the industry as synthetic mullite.
History and Production
The sillimanite group of minerals came into use for the manufacture
of mullite-bearing materials in the 1920's and consumption of these
materials has grown steadily ever since. United States demand was
largely supplied for many years by lump kyanite imported from India,
and later from Kenya. Kyanite, andalusite, dumortierite, and topaz
have been produced domestically from mines in California, Georgia,
Nevada, New Mexico, North Carolina, South Carolina, and Virginia
(Klinefelter and Cooper, 1961 ; Espenshade, 1962). Production from
the California mines (the White Mountain andalusite mine, Mono
County, and the Ogilby kyanite mine. Imperial County) ceased about
1945. United States production from 1950 to 1962 consisted of kyanite
concentrates from mines in South Carolina (Henry Knob deposit)
and Virginia (Baker Mountain and Willis Mountain deposits). In
1962 production of kj^anite concentrates was started from a mine at
Graves Mountain, Georgia. Current United States production comes
entirely from these four kyanite mines in Georgia, South Carolina, and
Virginia.
Over the years the supply pattern has gradually changed from
mainly foreign sources of material to predominantly domestic sources
at the present time. Another very significant change in the industry
has been the development of large-scale production of synthetic mullite.
The United States is now no longer dependent upon imported kyanite.
Kleinfelter and Cooper (1961, p. 30) state: "If imports were to be cut
off completely, the United States could become self-sufficient within a
few months by accelerating the production of synthetic mullite."
Free world production of kyanite minterals in 1963 was about 170,000
short tons, which came mostly from the Eepublic of South Africa,
India, the United States, and Australia, in order of production (Var-
ley, 1965 ) . The changing pattern of the domestic industry since World
War II is indicated in table 23.
Table 23. — United State.'< production of kyanite and synthetic mullite, and
imports and exports of kyanite {short tons)
1945
1951-55
yearly
average
1963
Kyanite production (estimated) '
Synthetic mullite production 2--.
Kyanite imports '
Kyanite exports 2_
12,300
(?)
14,554
307
22,000
17,000
9,531
1,203
44,800
29,588
2,624
5,050
I Varley (1965, p. 104).
^ Klinefelter and Cooper (1961, p. 32-33) and U.S. Bureau of Mines Minerals Yearbooks.
214 mineral and water resources of california
Geologic Occurrence
Kyanite, andalusite, and sillimanite all have the same chemical
composition (ALSiOs, consisting of 62.9 percent alumina and 37.1
percent silica), but have different crystal structure. They typically
occur in metamorphic rocks, but also in some quartz veins and pegma-
tites, and in some river and beach placers. Many deposits of these
minerals are evidently metamorphosed aluminous sediments, but in
some quartzose deposits hydrothermal processes seem to have been
active. Although the AlaSiOs minerals are very common in some
metamorphic rocks, they are rarely abundant enough or sufficiently
free of impurities (attached or included grains of other minerals)
for the deposits to be of economic value. They are generally most
abundant in quartzose metamorphic or altered rock, where they are
associated mainly with quartz, and in some places with other aluminum
silicates, and may constitute 20 to 40 percent of the rock; massive
segregations of the ALSiOs minerals may occur locally. These quartz-
ose deposits have been the most productive deposits in all parts of
the world. The ALSiO^ minerals are probably more widespread in
micaceous schist, gneiss, and hornfels, but rarely make up more than
about 15 percent of such rocks. Dumortierite (about 65 percent
alumina and 30 percent silica, plus boron) and topaz (about 55 percent
alumina and 33 percent silica, plus flourine) are not nearlj^ so common
as the AlzSiOs minerals; they may occur in quartzose masses and
quartz schist with other aluminous minerals, in quartz veins, and in
pegmatites.
Occurrences in California
All of the kyanite group of minerals have been found in California,
but in minable quantities at only two places : kyanite in a deposit near
Ogilby, Imperial County, and andalusite at the White Mountain
deposit. Mono County (fig. 32). Both deposits were mined during
the same period, from the 1920's to about 1945, and yielded a total
production of about 36,000 tons of aluminum silicate rock, according
to Wright (1957).
At the Ogilby deposit, kyanite occurs with quartz in very large
masses associated with quartzite and quartz-muscovite schist (Samp-
son and Tucker, 1931; Henshaw, 1942; and Wright, 1967). The
quartz-kyanite rock occurs discontinuously over a distance of about
a mile and has a maximum thickness of about 400 feet. Most of this
rock contains more than 15 percent kyanite; the mined rock is said to
have averaged 35 percent kyanite or iDetter. Only a small part of the
quartz-kyanite rock was mined ; bodies of similar but unmined quartz-
kyanite rocks are said to occur in the area (Wright, 1957). About
21,000 tons of ore was mined from several quarries; kyanite was sepa-
rated from decrepitated quartz by screening to give two products, one
with 50 percent kyanite and 50 percent silica, and the other with 70
percent kyanite and 30 percent silica (McLenegan, 1956). The Vitre-
frax Corp. of Los Angeles operated the Ogilby mine until 1946 ; the
Aluminum Silicates Co. of Los Angeles acquired the property in 1949
(McLenegan, 1956) , and is said to have recently leased the property to
Western InrUistrial Minerals Co. which may resume mining operations.
At the Wliite Mountain deposit. Mono Comity, andalusite and
diaspore occur in irregular veins and masses within a zone several
MINERAL AND WATER RESOURCES OF CALIFORNIA
215
118*
4-38-
Wh i te Mounta ins
Q_jinda I us i te depos i t
^ 116* «... .
Ogi Iby
kyan i te
de pos i t
Figure 32. Principal kyanite and andalusite deposits in California.
miles long and less than a mile wide in quartzite and quartz-sericite
schist associated with nietaporiDliyry and quartz monzonite (Jeffery
and Woodliouse, 1931 ; Lemmon, 1937 ; and Wright, 1957) . The main
mine working yielded about 20,000 tons of hand -cobbed ore that con-
tained 53 percent or more andalusite. Because of very rugged ter-
rain, this material had to be carried by mule back for 31/^ miles to a
truck depot. The mine was operated by Champion Sillimanite, Inc.,
and the ore shipped to the parent company. Champion Porcelain Co.,
Detroit, where it was mixed with clays, dumortierite from Nevada,
or alumina for the manufacture of porcelain and spark-plug cores.
Mmerals of the kyanite group occur in minor to moderate amounts
at numerous other localities in California. All the localities known
prior to 1958 are listed by Murdoch and Webb (1956 ; 1960) , who note
that andalusite is known to occur in 14 counties, kyanite and sillimanite
216 MINERAL AND WATER RESOURCES OF CALIFORNIA
in 7 counties each, topaz in 6 counties, and dumortierite in 4 counties.
The AlaSiOs minerals occur most abundantly in metamorphic rocks,
particularly in roof pendants of hornfels and schist in the Sierra
Nevada srranitic batholith.
fe'
Eesources
Probably the only deposits of the kyanite group of minerals known
in California that can be considered as resources are the White Moun-
tain andalusite deposit and the Ogilby kyanite deposit. Wright
(1957) states that they have remained idle "largely because no ready
market exists for the kyanite and because most of the known bodies of
higher grade and easily recovered andalusite had been removed."
McLenegan (1956) concluded that there is a potential market for these
minerals in California and Nevada of about 10,000 tons annually,
and that this demand could rise to 40,000 tons if adequate local sources
were found. As Wright (1957) indicates, revival of the kyanite-
andalusite mining industry in California will require the development
of local markets, discovery of sufficient high-quality ores, and the
ability to compete with synthetic mullite, as well as with kyanite pro-
duced from the southeastern states.
Selected References
Espenshade, G. H., 1962, Pyrophyllite, kyanite and related minerals in the United
States (exclusive of Alaska and Hawaii) : U.S. Geol. Survey Mineral Inv. Map
MR-18.
Henshaw, P. C, 1942, Geology and mineral resources of the Cargo Muchacho
Mountains, Imperial County, California : California Div. Mines Rept. 38,
p. 147-196.
Jeffery, J. A., and Woodhouse, C. D., 1931, A note on a deposit of andalusite
in Mono County, California ; its occurrence and technical importance : Cali-
fornia Div. Mines Rept. 27, p. 459-464.
Klinefelter, T. A., and Cooper, J. D., 1961, Kyanite, a materials survey ; U.S.
Bur. Mines Inf. Circ. 8040, 55 p.
Lemmon, D. M., 1937, Geology of the andalusite deposit in the northern Inyo
Range, California : Stanford Univ., impublished Ph.D. thesis.
McLenegan, J. D., 19.%, Refractories consumption and high alumina mineral
resources in California and Nevada : U.S. Bur. Mines Rept. Inv. 5183, 16 p.
Murdoch, Joseph, and Webb, R. W., 1956, Minerals of California : California
Div. Mines Bull. 173, 452 p.
, 1960, Minerals of California for 1955 through 1957 : California Div. Mines
Bull. 173, supp., 64 p.
Sampson, R. J., and Tucker, W. B., 1931. Feldspar, silica, andalusite, and kyanite
deposits of California : California Div. Mines Rept. 27, p. 450-458.
Varley, E. R., 1965, Sillimanite : Over.seas Geological Surveys (London), 165 p.
Wright, L. A., 1957, Kyanite, andalusite, and related minerals, in Mineral com-
modities of California: California Div. Mines Bull. 176, p. 275-280.
LEAD
(By R. M. Stewart. California Division of Mines and Geology, San
Francisco, Calif.)
Utilization
Lead probably was one of the first metals to be won from its ores
by smelting. The properties of lead that make it most useful are its
softness and workability, high specific gravity, extreme resistance
MINERAL AND WATER RESOURCES OF CALIFORNIA 217
to corrosion, and a combination of low-melting point aiid high-boiling
point. Estimates of lead usage in the United States indicate that 10
percent is used primarily because of its specific gravity; 30 percent
because of its softness, malleability and resistance to corrosion; 25
percent because of its alloying properties; and 33 percent because of
the properties of its chemical compounds (Perry, 1945, p. 66-67).
About three-fourths of the lead used is in a metallic form, alone or
alloyed. Although lead has a very wide variety of uses, about 54
percent was absorbed during 1963 by the two principal uses, storage
batteries, and gasoline antiknock additives. Pigments, chemicals,
cable sheathing, and construction materials constitute other major uses
of lead. Lead has the highest secondary recovery factor of the com-
mon metals; about 60 percent of the lead in use ultimately will be
recovered as scrap.
Geology
The primary mineral galena (PbS) is the chief ore mineral of lead
throughout the world, but the secondary minerals, anglesite (PbS04)
and cerussite (PbCOs) also are significant ore minerals in the oxidized
zone of some deposits. Other significant, although less abundant,
minerals in the oxidized zone of lead deposits are : those of the pyro-
morphite series (Pb5(P04As04)3Cl) ; linarite, a basic sulfate of lead
and copper; plumbojarosite (PbFe6(OHi2(S04)4) ; and wulfenite
(PbMo04). Silver and zinc minerals commonly are associated with
lead minerals in California as well as throughout the world. (See sec-
tions on silver and zinc in this report.) Primary lead-zinc deposits in
California typically occur as cavity fillings or replacement bodies, and
most occur in Paleozoic carbonate rocks. Most lead-zinc deposits
clearly are associated wtih intrusive igneous rocks.
In the oxidized zone, galena alters to anglesite which in turn alters
to cerussite. Anglesite and cerussite are relatively insoluble, and lead
ore is the most resistant of all base metal ores to further chemical al-
teration. Enrichment can take place in the oxidized zone, however,
by leaching of sulfur, zinc, and iron and possibly other constituents
from the ore. All of the lead deposits in California have been oxidized,
but primary sulfide minerals are present, in minor to major propor-
tions, in all of them.
History
The first lead mined in California probably was that produced from
the southern part of the Panamint Range prior to 1859 by Mormons,
and early developments were prompted by the silver content of the
lead ores. The Cerro Gordo district, which ranks second after Darwin
as a source of lead in California, was discovered prior to 1866, possibly
as early at 1862. Production started in the Tecopa district at the
Gunsight mine in 1865 ; and the first of the highly productive mines
in the Darwin district was discovered in 1874. Although discoveries
in other districts were being made during this same general period,
or followed closely, none was to equal any of these three in importance.
The principal mines in the Darwin district yielded ore valued at
about $3,000,000 prior to 1900; $4,000,000 between 1900 and 1945,
Avhen the Anaconda Copper Mining Co. purchased the principal
mines; and $18,000,000 between 1945 and 1953 (Carlisle, and others,
67-164 O— '616— pt. I 15
218 MINERAL AND WATER RESOURCES OF CALIFORNIA
p. 44) . Following a mid-year drop in lead and zinc prices in 1957.
Anaconda suspended operations at Darwin and at the Shoshone mines
in the Tecopa district.
The Cerro Gordo district is credited with ore valued at $17,000,000 ;
the Cerro Gordo mine has a total output valued at $15,000,000, and
although it was worked intermittently until the late 1940's, has not
been a significant source of lead since 1877.
Prior to 1947, all the mines in the Shoshone group had yielded about
250,000 tons of ore that had a gross value of about $5,000,000. More
than half of this was produced by the Tecopa Consolidated Mining
Co. during the period 1912-1928. As stated by Carlisle (1954, p. 46),
operations by the Anaconda Co. since 1947 resulted in the production
of more than 160,000 tons of ore that contained about 40,000,000
pounds of lead, 6,000,000 pounds of zinc, 870,000 ounces of silver, and
15,600 ounces of gold. The operations were suspended late in 1952,
were resumed in 1956, but terminated during 1957.
Lead production in California has been affected most by the national
and international situation and the resultant price structures, not
only for lead but for the other base metals and for silver as well. Un-
doubtedly, the production of lead in the future will be similarly
affected.
Production
In terms of total production, the United States has, since 1893,
been the world's chief source of lead, and, since 1900, has been the
chief user of the world's lead. Since 1940, however, the United States
has been forced to rely upon imports for a large part of the lead re-
quired by its expanding industrial complex. Since 1960, mines in
the United States have produced less than 10 percent of the world's
total and have supplied only about 23 percent of the total lead used
domestically. Recently discovered deposits in Missouri are now being
developed and may soon reverse this trend.
Deposits in California have yielded a total of about 495 million
pounds of lead from 1877 through 1964. This output represents only
about eight-tenths of one percent of the total mine production of
lead in the United States for the same period. During the decade
ending with 1964, the annual production of lead in California ranged
from a low of 103 tons in 1961 to a high of 9,296 tons in 1956. The
1964 production of 1,546 tons was the highest since 1957, when pro-
duction reached 3,458 tons. Mines in Inyo County have been the
source of about 93 percent of the State's total.
Occurrences in California
Most of the lead produced in California has been obtained from
three districts in Inyo County shown on fisrure 33. These are: the
Cerro Gordo district, about 13 miles east of Lone Pine and near the
crest of the Inyo Range ; the Darwin district, about 35 miles southeast
of Lone Pine; and the Tecopa district, at the southern end of the
Nopah Range in the southeastern corner of Inyo County.
The host rocks for the ore bodies in the Cerro Gordo district are
limestone, marble, and quartzite beds of Devonian age. The Devonian
and overlying Carboniferous rocks have been intruded by two small
stocks of monzonite porphyry and by dikes of monzonite porphyry,
MINERAL AND WATER RESOURCES OF CALIFORNIA 219
EXPLANATION
LEAD DEPOSITS IN INYO COUNTY
1. Cerro Gordo Mine and district
2. DarHin Mines and district
3. Defense Mine. Modoc District
4. Lippincott Mine
5. Santa Rosa Mine
6. Shoshone Mines, Tecopa district
7. Ubehebe Mines
Other mines and prospects
See section on copper^ silver
and zinc for distribution of
other lead-bearing deposits
in the St ate
Figure 33. Lead deposits in Inyo County.
diabase, and quartz-diorite porphyry, in that order (Carlisle and
others, 1954, p. 43). The ore bodies, all nearly vertical, south-plung-
ing, chimney-like bodies, were distributed, according to Knopf (1918,
p. 113), through a north- to northwest-trending zone 1,500 feet long
and several hundred feet wide. The ore minerals are argentiferous
galena, cerussite, anglesite, smithsonite, sphalerite, tetrahedrite, and
pyrite. Much of the zinc in the lead-rich deposits was removed by
meteoric water and formed secondary deposits.
The ore bodies of the Darwin district occur in Pennsylvania lime-
stone which is folded about northeasterly to northwesterly axes.
One of the major structural features influencing mineralization was
a northwest-plunging anticline, the axis of which lies near the crest
of the Darwin Hills. The limestone has been silicated in a wide zone
peripheral to a quartz diorite stock that was intruded mainly along
the core of this anticline and for an exposed distance of about 5 miles.
Mineralization is contact metasomatic ranging to mesothermal (Hall
and MacKevett, 1962, p. 69), related to the quartz diorite, and has been
guided by igneous contacts, bedding planes, and cross fractures. "In
order of importance, the orebodies are: (1) bedded replacements that
commonly are more or less localized along anticlinal flexures and lie
near but not in contact with the intrusive sills; (2) irregular replace-
220 MINERAL AND WATER RESOURCES OF CALIFORNIA
ments of (he silicated limestone along fissures; and (3) fissure filling:s"
(Carlisle and others, 1954, p. 45) .
The major primary sulfides are artjentiferous galena and sphalerite.
Minor to very minor proportions of pyrite, chalcopyrite, tetrahedrite,
bornite, chalcocite, and covellite are present. Extensive but irregular
oxidation has produced ceiiissite, anglesite, plumbojarosite., sooty
argentite, and cerargyrite. Leaching of zinc, sulfur, and some iron
has been important in the residual enricliment of the oxidized ore
(Davis and Peterson, 1949, p. 138) .
Nearly all the lead ore from the Tecopa district has been produced
from several mines that were consolidated as the Anaconda Copper
Co.'s Shoshone mines. The host rock for all the ore bodies is the
Noonday Dolomite of late Precambrian age which lies unconformably
upon Precambrian metamorphic and sedimentai'y rocks and is over-
lain by Lower Cambrian sedimentary rocks. The largest ore bodies
appear to have formed at junctions of the northwest-trending Sho-
shone fault with cross fractures and faults (Carlisle, and others, 1954,
p. 46). Most of the ore in each of the deposits is highly oxidized.
Cerussite and anglesite are predominant, and are associated with iron
oxides, smithsonite, calamine, linarite, and caledonite. Residual
galena, pyrite, and sphalerite are present in minor proportions.
The Santa Rosa mine at the southern end of the Inyo Range, and
several mines, notably the Defense, Minietta, and the Modoc, in the
northern end of the Argus Range (the Modoc district) in Inyo County
have been important sources of lead.
Most of the rest of the lead that has been mined in California has
been a by-product of the copper-zinc and gold mines of the Klamath
Mountains and Sierran foothill areas (see sections on copper, gold,
and zinc). Other areas that have yielded relatively small quantities
of lead ore include the Clark Mountain district in northeastern San
Bernardino County, a small district on the west slope of the Santa
Ana Mountains in Orange County, and the northern Panamint Range
in InyoCoimty.
Appraisal
It is doubtful that the deposits that have yielded most of California's
lead in this century are exhausted. The cessation of operations at
the larger mines, such as Darwin, probably was due more to an un-
favorable price stnicture for the metallic concentrates than to lack
of ore of a grade that in prior operations had been economically suc-
cessful. Tlie districts that have been the source of major proportions
of the California production undoubtedly will, again, be the sites of
further exploration when the price structure for lead (perhaps with
a boost from copper, silver, or zinc) becomes favorable. In the long
view, this situation is inevitable.
Selected References
Bishop, O. M., 1960, Lead, in Mineral facts and problems : U.S. Bur. Mines Bull.
585, p. 429-444.
Carlisle, Donald, and others, 1954, Base metal and iron deix)sits of s,outhern
California. [Pt.] 5 iu Chap. 8 of Jahns. R. H., ed.. Geology of southern Cali-
fornia : California Div. ]Mines Bull. 170, p. 41-49.
Goodwin, J. G., 1957, Lead and zinc in California : California Jour. Mines and
Geology, v. 53, p. 353-724.
Hall, W. E., and MacKevett, E. M., Jr., 1962, Geology and ore deposits of the
Darwin quadrangle Inyo County, California : U.S. Geol. Survey Prof. Paper
368, 87 p.
MINERAL AND WATER RESOURCES OF CALIFORNIA 221
Knopf, Adolph, 1918, A geologic reconnaissance of the Inyo Range and the
eastern slope of the southern Sierra Xavada, California : U.S. Geol. Survey
Prof. Paper 110, 106-118.
MacKevett, E. M., Jr., 1953, Geology of the Santa Rosa lead mine, Inyo County,
California : California Div. Mines Spec. Rept. 34, 9 p.
Moulds, D. E., 1964, Lead, in U.S. Bur. Mines Minerals Year book, 1963: U.S.
Bur. Mines, p. 701-735.
Norman, L. A., Jr., and Stewart, R. M., 1951, Mines and mineral resources
of Inyo County : California Jour. Mines and Geology, v. 47. p. 59-68, 80-81.
Perry, R. A., 1945, The lead industry: Min. Metall., p. 66-67, (Feb.).
Stewart, R. M., 1957, Lead, in Mineral commodities of California: California
Div. Mines Bull. 176, p. 281-292.
U.S. Bureau of Mines, 1965, Lead, in Commodity data summaries, p. 80-81.
LIMESTONE, DOLOMITE, AND LIME PRODUCTS
(By O. E. Bowen, California Division of Mines and Geology, San Francisco, Calif. )
Importance or Calcareous Materials in California
California, the most highly populated state in the union and also
among the fastest growing in population, is fortunate to have vast
resources of carbonate rocks to supply its expanding industries. Her
cement industry alone, largest in the United States and probably in
the world, for an equivalent political unit, consumes about 13,000,000
tons of limestone and fossil seashells each year. In excess of 4,500,000
tons of carbonate rocks are consumed annually by a great number
of other industries, led by : aggregates for the construction industry,
magnesian and high-calcium lime manufacturing, limestone and dolo-
mite for steel manufacturing, roofing granules for the construction
hidustry, limestone for sugar refining and limestone for glass manu-
facturing, as shown in table 24. The value of carbonate rocks to the
State's economy is immense, as it occurs widely distributed and is
available at a relatively low cost compared to other raw materials.
Table 24. — California consumption of limestone and dolomite during 1964 ^
T071S
1. Cement (from limestone, siliceous limestone, oyster shells) 12,750,000
2. Aggregates — including concrete aggregate, road base, etc. (from
limestone, magnesian limestone, dolomite) 2,000,000
3. Magnesian lime (from dolomite, magnesian limestone) 500,000
4. Steel flux (from limestone) 450,000
5. Roofing granules (from limestone and dolomite) 4.50,000
6. Sugar refining (from high-calcium limestone) 285,000
7. White fillers (from high-calciimi limestone ; includes whiting,
paper fillers, asphalt tile, linoleum, etc.) 210,000
8. Glass (from high-calcium limestone) 200,000
9. High-calciiim lime (from high-calcium limestone) 200,000
10. Agriculture (from limestone and oyster shells ; includes fertilizer
fillers, mineral foods, soil amendments) 135,000
11. Poultry grit (from limestone, oyster shells) 105,000
12. Riprap (limestone, magnesian limestone) 100,000
13. Dimension stone (limestone, magnesian limestone, dolomite) 70,000
14. Terrazzo chips 40,000
15. Asphalt filler (limestone, magnesian limestone) 12,000'
16. Miscellaneous (chemicals, concrete pipe, stucco, oil well drill-
ing, etc.) 150, 000
Total 17, 607, 000
1 Tonnajres are estimated and include commercial and noncommercial items as well as
imports. Data adapted in part from the U.S. Bureau of Mines, U.S. Census Bureau, and
sources in industry.
222 MINERAL AND WATER RESOURCES OF CALIFORNIA
Limestone is one of the few raw materials that are absohitely basic
in modern industry and necessary to our present civilization. In addi-
tion to its major use in the manufacture of portland cement, it is the
source of lime, for which there are over 7,000 uses. Most of these uses
depend oji the caustic properties of calcium oxide or calcium-mag-
nesium oxide produced by calcination of limestone or dolomitic lime-
stone. In some of these uses, it serves to combine with and remove
unwanted materials from a desired product as in the manufacturing
of steel, and the refining of sugar and petroleum. Many of its uses
are almost as old as recorded history, and because it is economical it
has been widely employed.
Origin, Accumulation, and Characteristics of Limestone and
Dolomite
Limestone occurs in nature in many degrees of purity. Calcium is
the principal metallic alkaline element which gives limestone the char-
acteristics which make it a fundamental raw material. Magnesium
is another metallic alkaline element present in all dolomites and in
some limestones. For some industrial uses, magnesium is an important
desirable constituent; for others, it is a harmful impurity. Alumi-
nous, siliceous- and iron-bearing impurities may be critically dele-
terious in some chemical processes and beneficial in others — as in the
manufacture of portland cement. Sulfur and phosphorus may be
present only in trace amounts if the limestone or dolomite is to be
used in steel manufacturing. For glass manufacturing, the iron con-
tent must be extremely low. Limestone, fossil seashells, magnesian
limestone, and dolomite are at present the only carbonate raw" mate-
rials that are economically feasible to mine in California at the present
time.
Calcite (CaCOg) is the predominating mineral in limestone. Dolo-
mite ( CaCOs.MgCOs) is the principal mineral in rock dolomite. Arag-
onite (also CaCOs) is the chief mineral secreted by organisms and
found in seashells, but it is metastable and in time changes to calcite.
In common industrial usage, a carbonate rock containing 95 percent
or more of CaCOs is termed high-calcium limestone; one containing
between 5 and 10 percent MgO is called magnesian or dolomitic lime-
stone; one containing between 10 and 15 percent is limy dolomite; and
one between 15 and 21.6 percent MgO is called dolomite. The terms
"high calcium" and "chemical grade" are used more or less syn-
onymously. In California, however, open-market availability of
high-grade limestones is such that any producer who expects to com-
pete in selling limestone or dolomite on the open market has to produce
a rock having more than 97 percent CaCOa, if he expects to sell it as
"high-calcium" or "chemical-grade" limestone, or it must contain
20 percent or more ]\IgO to compete as dolomite.
Many aquatic plants and animals, secrete calcium carbonate or a
mixture of calcium and magnesium carbonates for protective and sup-
porting parts. As many of these organisms are colonial or at least
gregarious in habit, their remains may accumulate and be preserved
in large concentrations. Micro-organisms also may contribute in-
directly to the chemical precipitation of carbonate minerals by up-
MINERAL AND WATER RESOURCES OF CALIFORNIA 223
setting the equilibrium of the aqueous system, by catalytic activity, and
so on. Changes in temperature and composition of ocean and lake
waters also may result in direct chemical precipitation of carbonate
minerals. Organisms appear to play the predominating role in lime-
stone formation, mechanical concentration of carbonate detritus plays
an important secondary role in limestone formation, and chemical
precipitation appears to play a lesser role. A few large deposits of
limestone have accumulated by direct chemical precipitation from
vents of warm mineral springs. Dolomite apparently forms chiefly
by replacement of pre-existing limestone masses, predominantly by
diagenetic replacement on the sea floor, but also by mobilization of
magnesian agueous solutions during the granitic emplacement phase
of fold-mountain building.
A great majority of California limestone and dolomite deposits
occur in metamorphosed or partly metamorphosed marine sedimentary
rock sequences. Most commonly, they are interbedded with non-
carbonat© sedimentaiy rocks and make up only a small part of the
stratigi'aphic section in which they occur. In a few remotely situated
parts of the State, i.e., southern Inyo and northern San Bernardino
Counties, carbonate rocks do form the bulk of some sedimentary sec-
tions and reach thicknesses of more than 10,000 feet. In contrast to
many other limestone and dolomite-producing states, California de-
posits tend to occur in steeply dipping, structurally complex, lenticular
bodies of small areal extent rather than in flat -lying or gently dipping
formations of large areal extent. Consequently, prospecting for lime-
stone in California is more complex than in most other states.
Probably the most common deleterious ingredient fomid in lime-
stone and dolomite is silica (SiOo) in the fonn of chalcedony or chert.
It occurs disseminated or in the form of streaks, nodules, or beds.
Quartz and feldspar sand grains as well as rock detritus are abundant
in parts of some California limestone and dolomite formations. These
impurities may be disseminated through limestone matrix or concen-
trated as partings and beds. Clay in the form of illite or kaolinite is a
conmion minor constituent of limestones and dolomites. In some for-
mations it is present in large amounts, so that the limestone grades
into shaly limestone or into marl in some parts of a formation. Such
rocks may be valuable sources of material for portland cement manu-
facture, but, for most other purposes, clay is a harmful ingredient in
both limestone and dolomite.
Another widely distributed impurity in California carbonate rocks
is organic matter in the form of hydrocarbons or gas, hydrogen sul-
fide being the commonest gas. In strongly metamorphosed carbonate
rocks, where recrystallization has been widespread, solid organic mat-
ter generally has been convei-ted to graphite, and the evolved gas has
been trapped in pores, minute fractures, and along cleavages in the
rock. In ciystalline limestone valued for its light color, graphite is
hannful because it smears badly during grinding and discolors the
ground product. A large amount of organic matter can be deleterious
in chemical processes where it commonly causes scmnming of a
solution.
Other constituents that may be troublesome in carbonate rocks are
pyrite, chlorite, glauconite, and collophane, but with the possible
exception of pyrite, none of these is common in California deposits.
224 MINERAL AND WATER RESOURCES OF CALIFORNIA
Invasion of a limestone by granitic intrusive rocks may result in intro-
duction, by replacement, of pyrite and other metallic sulfide minerals.
History of Utilization of Carbonate Rocks in California
The use of lime-bearing materials in California dates back to the
building of the Spanish missions, where witewash and lime mortars
were widely used in small quantities. Abalone shells, pismo clams, and
other shells obtained on the beaches were probably the first materials
burned into lime. Later, accumulations of fossil shells were found
and finally it was discovered that the crystalline limestones, so widely
distributed throughout California, could be used. Not until the gold
rush days of the early 1850's did lime become important to the con-
struction industry in California, but from then on hundreds of lime
kilns sprang up all over California. This rising demand was directly
related to the hazardous fires which repeatedly swept through towns
made of frame buildings. Field stone or brick buildings laid up in
mnd or in lime mortar became the standard type of construction
throughout the gold country, and many of these remain in use today.
A great deal of lime was imported from Europe to supply demand
during the early part of the gold rush period.
Both marble and limestone were used as structural materials in
buildings as early as 1850. The marble-cutting business, once substan-
tial in California, has almost disappeared, because high labor costs
make California marble noncompetitive with marbles from Italy,
Georgia, and elsewhere. Limestone has been used as railroad ballast,
road metal, and the like from gold rush days, and as concrete aggre-
gate since the turn of the century.
The lime manufacturing business probably had its heyday between
1880 and 1900 — in relation to its importance to the then current
economy, if not in actual tonnage produced. Vast banks of lime kilns
were constructed in the Santa Cruz Mountains, Santa Lucia Range,
Sierran foothills, Tehachapi Mountains, and the southwestern Mo-
jave Desert. Many of the lime companies were as important for their
day as the portland cement companies now are — in relation to the
rest of the economy.
Although Portland cement was invented in England as early as 1824,
it was not used to any great extent in California until the late 1850's
and 1860's. The first cement used here was imported from Europe.
Even then its use did not greatly supplant lime mortars nor did con-
crete become serious competition to masonry construction until about
the turn of the century. This was partly due to primitive methods of
making and handling cement which resulted in non-uniformity of the
product. Also, it was difficult to keep dampness from deteriorating
the stored cement.
Cement manufacturing in California dates from 1860, when a
hydraulic cement (a type manufactured at considerably lower tem-
peratures than Portland cement) was placed on the San Francisco
market. Apparently, limestone from beds in the Martinez FoiTuation
(Paleocene) and from Pleistocene fossil seashells were blended with
clay as the raw materials for this venture. The first cement approach-
ing a true portland cement was made at Santa Cruz in a brick kiln
about 1877 from crystalline limestone and clay. Another early plant
MINERAL AND WATER RESOURCES OF CALIFORNIA 225
that produced portland-type cement was built on the Jamul Eanch
in southern San Diego County in 1891. The California Portland
Cement Co. built a plant at Slover Mountain near Colton in 1895 that,
although enlarged and rebuilt several times, has been in continuous
operation through the present day.
Since the early 1900's, cement plants have been the largest consumers
of limestone in California, but numerous other industrial users of
limestone have been equally important to the economy of California,
even though the quantity of material they consume is smaller. The
many chemical industries which consume limestone, for its lime con-
tent, for the carbon dioxide that can be evolved, or both, seem to have
developed principally since 1900. Many had their beginnings through
the impetus of World War I. 'Limestone was quarried for steel flux
and copper refining flux as early as the 1880's, possibly as early as
1860. The use of limestone in sugar refining dates back at least to
1870 when E. H. Dyer built the first successful refinery at Alvarado,
Alameda County. The glass industry^, another major consumer
of California limestone, was initiated by the Illinois Pacific Coast
Glass Co. at San Francisco about 1897 and by the San Francisco
Glassworks (1890-1898).
Dolomite probably was first used in California as marble building
stone, particularly around Sonora and Columbia in the gold country.
Dolomite marble dimension stone was produced commercially in Inyo
County about 1888 and may have been produced in the Sonora-Colum-
bia area of Tuolumne County in the 1870's and 1880's. Production
of dolomite in California was intermittent and not large up to 1942.
Except for durable material used as crushed stone, the commonest use
for dolomite up to 1942 was as a basic flux in the manufacture of steel.
In 1942, the Henry J. Kaiser interests initiated the use of calcined
dolomite and seawater in the manufacture of magnesia for use in the
production of magnesium metal, and in 1945 began to produce mag-
nesia refractories. Within a decade, the other California producers of
magnesia altered their processes to use dolomite. These firms are by
far the greatest consumers of dolomite in California. Prior to the
advent of the use of dolomite in manufacture of magnesia, it had been
made by interaction of lime with sea water. Interaction of calcined
dolomite with sea water gives a substantially larger yield of magnesia.
Occurrence of Limestone and Dolomite in California
Most of the limestone and dolomite deposits in California occur in
strongly deformed and metamorphosed marine sedimentary rocks.
Most commonly they are of Paleozoic age although there are some of
Precambrian, Mesozoic, and Cenozoic ages. Unmetamorphosed Ter-
tiary algal limestones of good grade are found in the Eocene Sierra
Blanca Formation of Santa Barbara County, and the Paleocene Mar-
tinez Formation of the Santa Monica Mountains. 01igocene( ?) and
Miocene shell limestone of the Vaqueros Formation is extensively
quarried in San Luis Obispo County. Quaternary seashell deposits
have been exploited at San Francisco, Newport, and San Diego Bays.
Recent marl of caliche tyi>e has been quarried in a small way in Fresno
and San Diego Counties. Chalk, an earthy foraminiferal limestone,
is unknown in California.
226 MINERAL AND WATER RESOURCES OF CALIFORNIA
The principal areas where carbonate rocks are abundant and rea-
sonably near to markets and to transportation facilities are: (1) the
Klamath Mountains of Shasta and Siskiyou Counties, particularly the
southeast part adjacent to Redding; (2) the foothill belt of the Sierra
Nevada from Placer to Tulare Comity; (3) the Santa Cruz, Gabilan,
and Santa Lucia Mountains of the central Coastal Ranges; (4) the
Tehachapi Mountains and adjacent southernmost Sierra Nevada; (5)
the Argus and Panamint Ranges of Inyo County ; (6) the Victorville-
Oro Grande-Adelanto vicinity of the southwestern Mojave Desert;
(7) the northern San Bernardino Mountains adjacent to Lucerne
Valley; (8) the Mescal, New York, and Providence Mountains of
eastern San Bernardino County; (9) the northern part of the San
Jacinto Mountains including the Palm Springs-Lake Hemet and
Beaumont-San Jacinto areas; (10) the Big and Little Maria Moun-
tains of eastern Riverside County; and (11) the Coyote Mountains
of Imperial County, largest potential source for the San Diego market-
ing area.
Four formations have yielded industrial limestone in Shasta and
Siskiyou Counties: the Hosselkus Limestone (Triassic), the Kennett
Formation (Devonian) ; the McCloud Limestone (Permian) ; and the
Gazelle Formation (Silurian). The Hosselkus Limestone extends
south into the northern Sierra Nevada, but the others are confined
largely to the Klamath Mountains. The Kennett and Hosselkus for-
mations yield limestone that is predominantly blue-gray to black; the
McCloud yields predominantly dove-gray rock. The Hosselkus
Limestone has been metamorphosed very little and is fine grained;
rock from the other three formations commonly is recrystallized and
ranges from fine grained to medium grained. None of these forma-
tions has yielded white rock of high-calcium grade. Limestone, prob-
ably of Paleozoic age and of medium to course grain and blue-gray to
white hues, exist in the relatively inaccessible interior of the Klamath
Mountains, notably in the subrange known as the Marble Mountains.
Among the four formations, the McCloud Limestone probably con-
tains the largest resources, but in the most accessible parts both mag-
nesia and silica tend to be widely and sporadically distributed. The
Hosselkus Limestone contains more uniform rock. Limestone has
been quarried from the McCloud Limestone, near Redding, from the
Kennett Formation on Backbone Creek (a tributary to the McCloud
River), from the Hosselkus Limestone near Ingot, and from the
Gazelle Formation near Gazelle.
Several deposits of Hosselkus Limestone of potential economic
importance are in and adjacent to the Genessee Valley of Plumas
County, near the Western Pacific Railroad. They have not yet re-
ceived much attention because of the availability of more accessible
materials. The same is true of several deposits on the Feather and
Yuba Rivers of the northern Sierra Nevada.
In the west-central Sierra Nevada, most industrial limestone and
dolomite deposits are in discontinuous series of simple lenticular
masses in other metamorphic rocks or as pendants in granitic rock.
Less commonly, they occur in masses having complicated outlines be-
cause of severe folding. A few of the limestone deposits have yielded
fossils ranging, at various localities, from Mississippian to Permian,
but fossil e^^dellce is very sparsely distributed. A few small bodies
MINERAL AND WATER RESOURCES OF CALIFORNIA
227
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Figure 34. Principal limestone and dolomite districts in California.
occur ill Jurassic rocks. The principal districts in the west-central
belt that are producing commercial limestone or dolomite are the Cool-
Cave Valley and Diamond Springs-Shingle Springs areas of El
Dorado County; the Volcano district of Amador County; the San
Andreas district of Calaveras County; and the Standard-Sonora-
Columbia district of Tuolumne and Calaveras Counties.
The crystalline limestones of the west-central Sierran foothill belt
are associated with slate, metachert, phyllite, mica schist and green-
stone of the upper Paleozoic Calaveras Formation. The largest
masses occur east of the Mother Lode belt, but these are medium to
coarse grained and commonly are mixtures of limestone and dolomite
228 MINERAL AND WATER RESOURCES OF CALIFORNIA
SO that careful sampling and selective mining is often necessary. Rock
colors most commonly are blue-gray or white or variations of these.
Dolomite generally is white to off-white. A succession of relatiAely
small lenses (most not over a quarter of a mile long by 300 feet or less
thick) containing predominantly fine-grained, dense dove-gray to
blue-gray limestone is found in a narrow belt in the foothill area west
of the Mother Lode, from Placer County south to western Calaveras
County. On the whole, these lenses have been less intensely meta-
morphosed than deposits east of the Mother Lode, and limestone from
them holds its lump form much better during calcination. However,
only a few are large enough and of sufficiently high purity to be either
active or potential sources of industrial limestone.
Many of the central Sierran limestone masses are too magnesian to
be useful for purposes other than magnesian lime, although there are
a few nearly pure calcitic and dolomitic masses from which com-
mercial rock may be obtained without selective mining. The Stand-
ard-Sonora-Columbia district contains the largest, continuously ex-
posed masses of carbonate rock in the Sierra Nevada, rocks of this
kind underlying many square miles. However, replacement masses
and smaller patches of dolomite of very irregular shape make selection
of quarry sites difficult in this district.
In the southern Sierra Nevada, faulting along both east and west
margins of the range has resulted in greater elevation of the granitic
core and greater removal of the metasedimentary cover by erosion.
Consequently, there are notably fewer limestone deposits there than
in other parts of the province, and these are more remotely situated
from transportation systems and markets. Deposits in Tulare County
along the Kaweah and Tule River drainages (Three Rivers and
Porterville districts) are being developed in a small way as well as
those clustered south of Lake Isabella in Kern Countv.
Very fcAv reasonably accessible limestone deposits exist m the north-
ern Coast Ranges, and the market is limited because of the small
population. In the central Coast Ranges, large roof-pendants of
crystalline limestone and dolomite are found in the Santa Cruz,
Gabilan and Santa Lucia Mountains and in the Sierra de Salinas.
Carbonate rocks of these complexes, of probable Paleozoic age, com-
monly are coarse grained, and white and blue-gray colors predominate.
Both high-grade limestones and high-grade dolomite occur in deposits
large enough for major exploitation (masses aggregating tens to hun-
dreds of millions of tons) ; deposits of the northern Gabilan Range
and southern Santa Cruz Range supply much of the current demand
in the San Francisco Bay area. Nearly all of the dolomite currently
used in northern California is quarried from deposits in the northern
Gabilan Range. Dense, fine-grained limestones found in the Fran-
ciscan Formation of Jurassic and Cretaceous a^e also supply notable
tonnages to San Francisco Bay industries, particularly to the cement
plant at Permanente, Santa Clara County. Quaternary oyster shells
dredged from San Francisco Bay supply one cement plant at Redwood
City, San Mateo County.
The immense resources of coarse-grained, white crystalline lime-
stone of the Pico Blanco district constitute virtiially the only unde-
veloped major deposits of high-grade limestone close to tidewater
anywhere on the California, Oregon, and Washington coasts. They
MINERAL AND WATER RESOURCES OF CALIFORNIA 229
are close to State Highway 1, 25 miles southeast of Monterey and
only 3 airline miles from the Pacific Ocean. Lack of close railroad
facilities and access roads has hindered their development thus far.
Tertiary unmetamorphosed limestones of considerable present eco-
nomic importance, and even greater future significance as the popu-
lation increases, are sparsely distributed in the southern Coast Kanges
of San Luis Obispo, Santa Barbara and Ventura Counties. Beds
of shell limestone in the 01igocene(?) and lower Miocene Vaqueros
Formation are quarried at Lime Mountain west of San Miguel for
use in sugar refineries of Salinas Valley. Deposits of algal limestone
in the P^ocene Sierra Blanca Formation can supply good quality,
dense limestone to industries in Santa Barbara and Ventura Counties
should the demand rise.
Extensive deposits of carbonate rocks in the Tehachapi Mountains
between Mojave and Frazier Mountain support two cement plants, one
at Mojave and one at Monolith. Other industries to be based on
these deposits are in the planning stages. The carbonate rocks occur
as pendants more or less encased in granitic rocks, either alone or
interbedded with mica schist and quartzite in sequences referred
to either the Bean Canyon Formation or the Kernville Series. These
rock groups are probably of late Paleozoic and/or early Mesozoic
age, although fossils have not been found in them. The rocks are
commonly coarse grained and colors range from white to blue-gray.
Masses of dense, fine-grained rock are unknown in this area. Lime-
stone, dolomite, and magnesian limestones are all present within the
district. Some very pure, very white, very coarse-grained limestones
exist west of Cantil at the headwaters of the Back Canyon drainage.
Potentially exploitable deposits of both limestone and dolomite occur
in Neenach quadrangle east of Lebec, and large deposits of cement-
grade rock are distributed through the district. Granitic intrusions
are common within many of the limestone bodies, and silica and
silicate minerals introduced by contact metamorphism are also a com-
mon problem in the district.
The chemical plants located at Searles Lake, Inyo County, to-
gether with the rail facilities that serve them, create a favorable eco-
nomic environment that allows the extensive limestone deposits (Car-
boniferous?) of the Argus Eange to be exploited. Carbonate rock
deposits across Panamint Valley in the Panamint Range may ulti-
mately be brought into production. Both high-grade dolomite and
limestone are foimd there. Light-gray colors prevail, and both lime-
stones and dolomites are medium to fine grained.
Extensive de}x)sits of fine-grained white dolomite are being mined
imderground near Keeler in the Owens Valley of Inyo County for
use as terrazzo chips and white .aggregate for the Los Angeles market-
ing complex. Immense reserves of dolomite exist there, and lime-
stone deposits can be developed farther to the east. The dolomite is
in the Ely Springs and Hidden Valley Dolomites of Ordovician to
Devonian age, whereas the best limestone is in the Lost Burro Forma-
tion of Middle and Late Devonian age.
In the Victorville-Oro Grande district of southwestern San Ber-
nardino County, limestone, dolomite, and dolomitic limestone are all
found in commercial quantities.
Tliese may occur singly or together in a given deposit and in places
are interbedded with other metasediments such as mica schist, quartz-
230 MINERAL AND WATER RESOURCES OF CALIFORNIA
ite, and homfels. The carbonate rocks are in the Carboniferous (?)
Oro Grande Formation and also in the conglomerate member of the
Permian Fairview Valley Fonnation. A majority of the carbonate
masses of the district consist of strongly metamorphosed, coarsely
crystalline rock, but there .are a few bodies of weakly metamorphosed,
dense, fine-grained rock of notable size at Sparkhule Hill and Black
Mountain. Limestone ranges from pure white to nearly black, but
white and gray or variegated combinations of the two colors are com-
monest. The Victorville-Oro Grande district ranks among the largest
limestone producers in the State, but only a little dolomite and dolo-
mitic limestone has been marketed thus far from the district because
of small demand. Granitic intrusions and introduction of silicate
minerals along granitic contacts are the principal problems in
exploitation.
There are immense resources of limestone and magnesian limestone
in the northern part of the San Bernardino Mountains of San Ber-
nardino County in the Furnace Limestone. This is at least partly
equivalent in age and lithology to the Oro Grande Formation of the
nearby Victorville-Ore Grande district. In general, these rocks are
strongly metamorphosed and coarsely crystalline, but there are some
patches of finer-grained, dense, more weakly metamorphosed rock.
^Vliite and blue-gray hues prevail, and select wliite rock is in demand
for white filler and roofing granules. White rock has been quarried
intermittently in the Cushenbury district for many years, and there
is a cement plant near the mouth of Cushenbury Canyon.
Extensive deposits of white, coarsely crystalline limestone rind
cream-colored dolomite occur in the Little and Big Maria Mountains
of eastern Riverside County near the railhead at Midland, particularly
a few miles northwest of Midland. The relatively long distince from
the Los Angeles marketing area and unfavorable freight rates have
limited production thus far, but it is likely that they will be activated
in the near future. The limestone and dolomite occur in strongly
deformed, intensely metamorphosed crystalline complexes of Paleo-
zoic or Precambrian age. INIany of the limestone deposits are of verv
high purity. Tlie dolomites have too high an iron content for some
uses, but otherwise some deposits are of good grade.
In the Riverside-Colton district pendants of limestone of Paleozoic
or Triassic age have supplied cement plants and numerous users of in-
dustrial limestone since 1895. Enormous tonnages of limestone have
been quarried at Slover Mountain near Colton and at Crestmore near
Riverside. The cement plant at Colton has been in continuous opera-
tion since 1895. Plants at Crestmore and Colton have just been re-
built, indicating that reserves are far from depleted. White, and
blue-gray colors prevail and the rock is coarsely crystalline. Both
cement-grade and high-purity limestones are present. Properties in
the district are owned almost exclusively by the two operating cement
companies. Several large, undeveloped deposits occur in the San
Jacinto and Santa Rosa Alountains of Riverside County within the
area enclosed by a line connecting Beaumont, San Jacinto, Hemet, and
Palm Springs, particularly northeast of Lake Hemet. Limited water
supply and competing land use plans have hindered development of
these favorably located deposits.
MINERAL AND WATER RESOURCES OF CALIFORNIA 231
A series of pendants and structural blocks containing crystalline
limestone deposits are along the San Andreas fault zone in the vi-
cinity of Wrightwood in the northeastern San Gabriel Mountains.
As these deposits are near the Los Angeles marketing complex, sev-
eral have intermittently produced industrial limestone. Few if any
of them are sufficiently large to support a cement operation. The
limestone ranges from white to blue-gray and is generally coarse
gi-ained.
The rapid growth of the San Diego metropolitan area has greatly
increased the market potential for limestone, cement, and lime prod-
ucts. Large deposits found in the Coyote Mountains of western Im-
perial County or rock imported from Baja California below Todos
Santos Bay ultimately will have to supply this increased demand,
although smaller deposits exist in the Dos Cabezas, Jacumba, and
Verruga vicinities of eastern San Diego County. There are no large
deposits in either San Diego or adjacent Orange Counties. In the
Coyote Mountains, very large resources of blue-gray to white, mediiun-
to coarse-crystalline limestone and some dolomite occur in a crystal-
line complex of late Paleozoic or early Mesozoic age. Overlapping
this crystalline core are discontinuous masses of shell-bearing lime-
stone up to 50 feet thick of Miocene age. These are of two sorts,
one a compact, pinkish-cream-colored limestone (by far the most
abundant), and a friable, dark-colored shell limestone or coquina
which occurs in lenticular beds less than 20 feet thick. Both types
are low in magnesia and could serve as supplemental sources of
cement-grade limestone if the much larger crystalline limestone de-
posits are brought into production. Some of the latter are a little
high in magnesium for cement, but large bodies suitable for cement
are present, notably in the vicinity of Carrizo Mountain.
The Mescal, New York, and Providence Moimtains are adjacent
mountain ranges in eastern San Bernardino County reasonably close
to the Union Pacific Kailroad that contain very large resources of
limestone and dolomite. These have been exploited in only a small
way, because water supply, living conditions, distance from markets
and rail-freight rates have been unfavorable. They are likely to be
more extensively developed in the near future. The carbonate rocks
range from white through dove-gray to dark blue-gray. Both fine-
grained, dense rocks and medium- to coarse-crystalline varieties are
found in the district. Limestones of industrial grade occur in the
Triassic Moenkopi Formation, the Yellowpine and Bullion Members
of the Mississippian Monte Cristo Limestone, the Crystal Pass Mem-
ber of the Devonian Sultan Limestone, and even in some parts of the
Cambrian to Devonian ( ?) Goodsprings Dolomite. Potentially usable
dolomite occurs in Goodsprings Dolomite, the Ordovician Ely Springs
Dolomite, the Ironside Dolomite Member of the Devonian Sultan
Limestone and in the Cambrian Bonanza King Dolomite.
Limestone and Dolomite Resource Potential
California's resources of limestone, dolomite, and cement materials
are very large in most grades of rock for most use categories and are
more than adequate for the foreseeable future. The carbonate rock
commodities are low-priced, and, as transportation costs form a sig-
232 MINERAL AND WATER RESOURCES OF CALIFORNIA
nificant part of total cost to the user, adjacency to markets is of prime
importance. The areas of coastal or tidewater industries, for example,
are very poorly supplied, and demand there may ultimately be satis-
fied by imports because water- frei^rht rates are cheap. The search for
higher valued deposits of very high purity, or deposits of very white
or attractively colored rock continue — particularly for deposits well
located with respect to potential consumers. At the present time, most
producing deposits lie within 150 miles of marketing centers and a
majority are within 75 miles of such centere. As the better-grade
deposits close to market are depleted, it will be necessary to go farther
from market or else to go more intensively into beneficiation of low-
grade deposits situated close to markets. Competition and conflicting
uses for land also tend to drive quarry and mine based industries
farther and farther from markets.
Because of remoteness, lack of water, or poor living conditions at
some southern California deposits, some classes of carbonate rock for
southern California markets are supplied from Nevada. Improved
transportation and freight handling or adjustment in current rail-
freight rates could change this situation. The burgeoning population,
with its resultant expanding manufacturing and construction indus-
tries, offer business opportunities unmatched elsewhere.
Carbonate Rock Districts of Particular Major Future
Importance
The San Diego marketing area ultimately will have to be supplied
from the Coyote and Fish Creek Mountains of Imperial County, as this
is the closest district containing major resources. Smaller deposits
such as those at Dos Cabezas, Jacumba, and Montezuma Valley may
be developed for local needs. Deposits south of Punta Banda, Baja
California, could provide imports into the San Diego area.
The notable resources of white crystalline limestone in the Little
and Big Maria Mountains of eastern Riverside County may soon be
developed, particularly if favorable rail-freight rates are established.
Deposits in the San Jacinto and Santa Rosa Mountains of Riverside
County are large and of fairly good quality.
Deposits in the Mescal, Ivanpah, New York, and Providence Moun-
tains, all of which are reasonably close to a railroad, are of near-
future interest. Also, those in the Tehachapi Mountains and southern-
most Sierra Nevada between Mojave and Frazier Mountain are of
future interest.
With the opening up of the interior of Santa Barbara and Ventura
Counties, the extensive high-grade limestone deposits in the Eocene
Sierra Blanca Formation ultimately will be utilized. Lack of good
access roads has limited their development thus far, and the popula-
tion and market situation is just reaching a favorable stage to attract
new industries.
Development of deep-water port facilities and an industrial complex
around Moss Landing on Monterey Bay probably will result in devel-
opment of the immense, high-grade, white crystalline limestone de-
posits at Pico Blanco, Monterey County. These are the only large
deposits of high-grade limestone close to tidewater on the Pacific Coast
of California, Oregon, and "Washington.
MINERAL AND WATER RESOURCES OF CALIFORNIA 233
Selected References
Blanks, R. F., and Kennedy, H. L., 1955, The technology of cement and concrete:
New York, John Wiley and Sons, 414 p.
Bogure, R. H., 1955, The chemistry of portland cement : New York, Reinhold Pub.
Corp., 2d ed., 798 p.
Bowen, O. E., 1957, Limestone, dolomite, and lime products, in Mineral commodi-
ties of California : California Div. Mines Bull. 176, p. 293-306.
Bowen, O. E., and others, in press. Limestone, dolomite and iwrtland cement in
California : California Div. Mines and Geology Bull.
Bowles, Oliver, 1952, The lime industry : U.S. Bur. Mines Inf. Circ. 7,651, 43 p.
, 1956, Limestone and dolomite : U.S. Bur. Mines Inf. Circ. 7,738, 29 p.
Clausen, C. F., 1960, Cement materials, //; Industrial minerals and rocks : New
York, Am. Inst. Mining Metall., and Petroleum Engineers, p. 203-231.
Gillson, J. L., and others, 1960, The carbonate rocks, in Industrial minerals and
rocks : New York, Am. Inst. Mining Metall., and Petroleum Engineers, p. 132-
201.
Ham, W. E., and others, 1962, Classification of carbonate rocks : Am. Assoc. Pe-
troleum Geologists Mem. 1, 272 p.
Johnson, J.H., (compiler), 1952, Studies of organic limestones and limestone-
building organisms : Colorado School Mines Quart., v. 47, no. 2, 94 p.
Johnson, J. H., 1954, An introduction to the study of rock-building algae and algal
limestones : Colorado School Mines Quart., v. 49, no. 2, 117 p.
Key, W. W., 1960, Chalk and whiting, in Industrial minerals and rocks: New
York. Am. Inst. Mining Metall., and Petroleum Engineers, p. 233-242.
Kirk, R. E., 1952, Lime and limestone, in Encyclopedia of Chemical Technology :
New York, Intrascience Encyclopedia Inc., v. 8, p. 346-381.
Lamar, J. E., 1961, Uses of limestone and dolomite: Illinois State Geol. Survey
Circ. 321, 38 p.
Logan, C. A., 1947, Limestone in California : California Jour. Mines and Geology,
V. 47, no. 3, p. 175-351.
LITHIUM
(By G. I. Smith and W. P. Irwin, U.S. Geological Survey, Menlo Park, Calif.)
Most of the lithium obtained in California comes from saline brine
in Searles Lake, one of the chief sources of the world's lithium,
although known mainly for its other extractable components (see
chapter on Sodium carbonate) . Much larger production of lithimn
concentrate has come from pegmatite deposits in North Carolina;
smaller quantities of pegmatite material come from the Black Hills
in South Dakota. Other states from which lithium has been obtained
are Arizona, New Mexico, Colorado, Wyoming, Massachusetts, New
Hampshire, and Maine.
Lithium has many uses. Major quantities are used in lithium
greases, ceramics and glass, welding and brazing, and air conditioning.
Large quantities have also been purchased by the Atomic Energy
Commission whose interests probably include both the neutron absorp-
tion capacity of the lithium-6 isotope, and the high-energy potential
of the nuclear reaction l)etween lithium-6 and deuterium. Smaller
quantities of lithium are used in production of batteries, pharmaceu-
ticals, alloys, and as a catalyst. Future uses may include lithium as
a heat-exchange mediiun in thermonuclear reactoi's, as a catalyst for
new processes, and in new alloys. The lithium-6 isotope forms about
7.5 percent of the lithium in natural deposits, and, if it becomes widely
used for shielding and as a reactant in nuclear power plants, large
quantities of tjie more abundant lithium-7 isotope might be left over
for other uses (Schreck, 1960; Kesler, 1960; Eilertsen, 1964).
67-164 O— 66— pt. I 16
234 MINERAL AND WATER RESOURCES OF CALIFORNIA
Minable lithium deposits are known on every continent. Of those
being mined today, all except the deposit in California are pegmatites.
Published data suggest that in 1963 the largest production outside the
United States was in Khodesia, but large quantities also came from
other African nations, Australia, and Canada. Unreported amounts
w^ere produced in South America, and production from one or more
Conunmiist nations is likely (Eilertsen, 1964) .
In 1954 the United States produced about 38,000 tons of lithium
minerals and compounds containing almost 2,500 tons of lithium oxide.
This was valued at $3,126,000 (Schreck, 1961). At about the same
time, the American Potash & Chemical Corp. at Searles Lake was
estimated to have an annual production capacity of lithium carbonate
equivalent to 200 to 300 tons of lithium oxide, or about 10 percent of
national production (Ver Planck, 1957). Production figures for the
years after 1954 have not been published.
The production of lithium from the concentrated brines of Searles
Lake started in 1938. The complex process used yields dilithium
sodium phosphate along Avith six other products, then converts it to
lithium carbonate for shipment. The brines, which average about
0.015 percent lithium oxide, are pumped from the upper of two saline
layers that were deposited during late Quaternary time (see section
on Sodium carbonate). Lithium minerals, however, have not been
found. Although the total production of lithium from this deposit
will actually be determined largely by the reserves and future prices
of its co-products, the lithium in it constitutes a sizable percentage of
the United States indicated reserves (Norton and Schlegel, 1955;
Kesler,1960).
Prior to the recoverv of lithium from the brines of Searles Lake,
California production of lithium-bearing minerals was from pegma-
tites of the Pala district in northern San Diego County. The total
reported production of lithium minerals mined from these pegma-
tites is 23,480 short tons, valued at 432,800, for the period 1900-1928.
Nearly all of this production was from the Stewart mine. The prin-
cipal lithium-bearing mineral of the Pala district is the lithium-rich
mica lepidolite, followed in order of importance by spodumene and
amblygonite. The lithium deposits of the Pala district are chiefly
zoned pegmatites; the spodumene generally occurs in the core and
intermediate zones, and the minable concentrations of lepidolite mostly
occur as a replacement of the primary pegmatite minerals along the
lower parts of the spodumene-rich zones (Jahns and Wright, 1951).
Additional sources of lithium in California appear to be few. Ab-
normal concentrations occur in clays in the Mojave Desert. One, near
Hector, contains a little over 1 percent lithium oxide (Foshag and
Woodford, 1936; Ames, Sand, and Goldich, 1958) : another, northeast
of Amboy, contains 0.50 percent (Foshag and Woodford, 1936) ; still
another, near Boron, is reported to contain 0.5 to 1.0 percent (Kesler,
1960). These percentages are close to those required for profitable
operations from pegmatites (Norton and Schlegel, 1955), but the
deposits are not currently considered economic sources of lithium.
Brines from geothermal wells in the Salton Sea area contain about
0.065 percent lithium oxide (White, 1965), but whether such com-
ponents as lithium can be extracted will not be determined until sev-
eral complex engineering problems have ])een solved.
MINERAL AND WATER RESOURCES OF CALIFORNIA 235
In two other western States, however, steps are beino; taken to ex-
tract lithium from brines in amounts wliich may have major impact
on all facets of the industry. A dry lake at Silver Peak, Nevada, is
being: developed by the Foote Mineral Co. as a source of lithium; the
subsurface brines are reported to be 6 to 7 times richer in lithium than
other known source brines (P^n^. Mining Jour., 1965; Wall Street
Jour., 1965). An option on brines from Great Salt Lake, Utah, has
been taken by Lithium Corp. of America for future extraction of
lithium chloride plus other products (P^ilertsen, 1964).
Selected References
Ames, L. L., Jr., Sand, L. B., and Goldich, S. S., 1958, A contribution on the
Hector, California, bentonite deposit : Econ. Geology, v. 53, no. 1, p. 22-37.
Eilertsen, D. E., 1964. Litliium : U.S. Bur. Mines, Minerals Yearbook, 1963, v. 1,
p. 751-755.
Engineering and Mining Journal, 1965, Foote Mineral Co., in Nevada : Eng.
Mining Jour., v. 166, no. 4, p. 148.
Foshag, W. F., and Woodford, A. O., 1936, Bentonitie magnesium clay mineral
from California : Am. Mineralogist, v. 21, no. 4, p. 238-244.
Jahns, R. H., and Wright, L. A., 1951, Gem- and lithium-bearing pegmatites of
the Pala district. San Diego County, California : California Div. Mines Spec.
Rept. 7A, 72 p.
Kesler, T. L., 1960, Lithium raw materials, in Industrial minerals and rocks :
New York, Am. Inst. Mining Metall. Petroleum Engineers, p. 521-531.
Norton. J. J., and Schlegel, D. M., 1955, Lithium resources of North America:
U.S. Geol. Survey Bull. 1027-G, p. 325-350.
Schreck, A. E., 1960. Lithium, in Mineral facts and problems: U.S. Bur. Mines
Bull. 585, p. 473-479.
, 1961, Lithium, a materials survey : U.S. Bur. Mines Inf. Circ. 8053, 81 p.
Ver Planck, W. E., 1957, Tiithium and lithiimi compounds : California Div. Mines
Bull. 176, p. 307-312.
Wall Street Journal, 1965, Foote mineral preparing brine .source of lithium :
Wall Street Jour., May 10, p. 5.
White, D. E., 1965, Saline waters of sedimentary rocks : Am. Assoc. Petroleum
Geologists Mem. 4. p. 342-366.
MAGNESIUM COMPOUNDS
(By A. R. Smith, California Division of Mines and Geology, San Francisco,
Oalif.)
Three plants in California Droduce macnesium comoounds from
sea water and sea water bittern by treatment wdth calcined dolomite
(Ver Planck, 1957). Plants at Newark, Alameda County, and Moss
Landing, Monterey County produce magnesia refractories and spe-
cialty magnesias. Magnesium compounds of high purity for phar-
maceutical and other chemical uses are manufactured in South San
Francisco. A fourth operation in Chula Vista, San Diego County
produces magnesium chloride from bittern without the use of dolomite.
The most miportant commercial magnesium compounds produced
in California are : the hydroxide, oxide, chloride, carbonate, trisilicate,
and sulfate. The production of magnesium oxide from sea water is
essentially one of reacting calcined dolomitic lime (combination of
calcium and magnesium oxides) with sea w^ater to form magnesium
hydroxide; the magnesia comes from both the calcined dolomite and
sea water in about equal amounts. This magnesium hydroxide is
then fired in rotary kilns to form magnesia that ranges from 65 to 98
percent MgO.
236
MINERAL AND WATER RESOURCES OF CALIFORNIA
111 California, magnesium hydroxide also is the raw material for
manufacturing basic magnesium carbonate which elsewhere is made
from dolomite. Magnesium chloride is obtained at the Chula Vista
plant, San Diego County by evaporating, with heat, bittern from an
adjoining salt plant — discarding the precipitate and concentrating the
liquor. To produce the trisilicate, sulflate, and other magnesium com-
pomids, caustic calcined magnesia is used in chemical combination
with the necessary acid radical. These are, for the most part, specially
processed to meet rigorous physical and chemical standards. Loca-
tion of the plants is shown on figure 35, and products are listed in
table 25.
EX PLANAT I ON
D
PLANTS
Fibrtboard Papsr Product! Corp. |.
Philadelphia Quartz Co. of Calif.
Food Machinery and Chanical Corp..
NtHBrii plant
Food Hachinary and Chaaiical Corp..
Chula Vista plant
0. Kaisar AluBinu* and ChcBical Corp.,
Hots Landing oparalion
1. Marina Magnaiiuv Products Division.
■trek and Co. . Inc.
MA6NESITE DEPOStTS
I. Bald Cagia Mine
7. Cadar Mountain
3. Frasno
4. Gray Eagia Mine
5. Harhar Mina
6. Ha Ml
7. Hiion Rartch
6. Kings
9- flad Mounta in Mina
I 0. Rad S I Ida dapos it
1 1 . Saapson Mi na
12. Snovf laha and Blanco Mines
13. Success area
14. Sull ivan
15. lestern Mme
IB. Ihite Rock Hint
DOLOMITE QUARRIES AND SDK OTHER
POTENTIAL DOLOMITE AREAS
Hollister dotonita quarry. Food
Machinery and Chasical Corp.
Natividad dolonila quarry. Raiser
AluffinuH and Cheancal Corp.
Kae lar - independence area. Inyo County
Sen Bernardino Mountains
S lar ran f ooth 1 1 I dapos i li
Victory 1 1 le-Or 0 Brande deposits
Figure 35. Map showing locations of plants producing magnesium compoimds
in California, some areas with commercial grade dolomite, and selected mag-
nesite deposits.
MINERAL AND WATER RESOURCES OF CALIFORNIA
237
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238 MINERAL AND WATER RESOURCES OF CALIFORNIA
The chemical and physical properties of the tAvo general classes
of magnesium oxides are largely defined by the temperature of cal-
cination :
a. Dead-humed magnesia (refractory grade) is produced by burn-
ing magnesite or magnesium hydroxide above 1,450° C. The result-
ing magnesium oxide granules are chemically inert, (with less than
2 percent carbon dioxide) and contain various proportions of iron
oxide, silica, alumina, and lime, either as impurities in the raw ma-
terial or as additives. "Periclase"', of which most refractorj- brick
is presently made, is a dense crystalline magnesia containing over 90
percent MgO, with chromite and silica as the principal additives. It
is made by firing this mixture to extreme temperatures, 1,760° C or
greater, depending on the type of bond desired for the brick. Natural
magnesia is the mineral periclase.
b. Gmistic-calc'med magnesia is produced by calcining magnesium
hydroxide at temperatures of at least 1,200° C or to such degree that it
contains less than 10 percent ignition loss (carbon dioxide and water),
and slakes in water or air. It may contain 90 to 98 percent MgO :
iron oxide, silica, alumina, and lime are undesirable impurities.
Eefractory magnesia is consumed mainly by the steel industry to
line open-hearth steel furnaces, either directly as grains or in refrac-
tory bricks and mortars. Other major uses of magnesia refractories
are in copper and lead smelters, in rotary kiln applications of the
Portland cement industry, and the magnesia calcining plants them-
selves. The use of dead-burned magnesia is increasing at a rate
greater than the growth in use of metals, since magnesia refractories
have increasingly supplanted other refractories in the metal-makmg
industry. In 1930, the total apparent consumption of dead-burned
magnesia by all industries was equivalent to about 4.16 pomids per
ton of steel. By 1945, the figure had increased to 6.5 and in 1963 was
about 14 pounds per ton of steel produced in the United States.
The largest single market for caustic-calcined magnesia is in mag-
nesium oxj'Chloride and oxysulfate cements, which are used mainly
for fireproof, resilient flooring. The cement is prepared by mixing
a solution of magnesium chloride or sulfate with ground, caustic-
calcined magnesia. Other major uses for caustic-calcined magnesia
are in the paper pulp, rayon, fertilizer, insulation, and chemical in-
dustries. The other specially prepared magnesium compounds made
in California are used to manufacture a variety of products. The
rubber industry uses magnesium oxide in various synthetics (hypalon,
neoprene, butyl) ; magnesium oxide, carbonate, hydroxide, and trisil-
icate are primary ingredients in antacid preparations.
Magnesium metal is used as a structural metal, an alloying con-
stituent for other metals, and as a reducing agent to produce titanium,
zirconium, hafnium, uranium, and beryllium. Since 1956, the metal-
lurgical uses for primary magnesium have exceeded the structural
uses, and in 1964 amounted to about 62 percent of the total use
figure. Magnesium as an aluminum alloy accounts for two-thirds of
this metallurgical classification. Since 1945, primary magnesium has
not been produced in California. Magnesium production is shown on
table 26.
MINERAL AND WATER RESOURCES OF CALIFORNIA
239
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240 MINERAL AND WATER RESOURCES OF CALIFORNIA
Magnesium, the eighth most abundant element in the earth's crust,
averages 2.09 percent in igneous rocks and about 4.77 percent, in lime-
stones. Magnesium is the second most abundant metal after sodium
in sea water, which contains the equivalent of 0.21 percent MgO as
a chloride or sulfate. The most important magnesium-bearing min-
erals are dolomite (Ca.,Mg) (CO3), magnesite (MgCOa) and brucite
(Mg(OH)2. With the exception of a few hundred tons of imported
brucite (used in the manufacture of epsom salt), sea water and dolo-
mite are the only raw materials presently used in California's mag-
nesia industry. Magnesite is mined at Chewelah, Washington, and
Gabbs, Nevada (also the source of some brucite) ; elsewhere, olivine
(MgFe)2Si04, foi-sterite (MgoSi04), and serpentine (H4Mg3Si209)
have minor uses as refractories, and as a source of magnesium
compounds.
Prior to World War I, magnesite was not regularly produced in the
United States; the needs for industry were met by imports, largely
from Austria and Hungary. The first recorded production in Cali-
fornia, and possibly in the United States, was from Cedar Momitain,
Alameda County in 1886. However, the amount mined was small, and
annual magnesite production in the United States (centered entirely in
California) did not reach 10,000 tons until 1910. The first commer-
cial production of magnesium compounds from sea water was obtained
in 1928 at South San Francisco. The present operation is still on the
original site and, since 1951, has been the Marine Magnesium Products
Division of Merck & Co.
The volume of magnesite mined in California between 1910 and
1945 followed the fortunes of two world wars, until it finally suc-
cumbed to dolomite and sea water as a source. xVnnual production of
magnesite, used mainly for refractory purposes, rose to more than 200
thousand tons by 1917, most of which came from C^ilifornia. Produc-
tion dropped to a low in 1938, and rose slightly in 1941 to only 50
thousand tons in California during the start-up period of the mag-
nesia plant built by Westvaco Chlorine Products Corp. at Newark.
The mining of magnesite, henceforth, declined steadily in California,
with the increasingly efficient manufacture of magnesia from dolo-
mite and sea water, until the Western mine stopped regular produc-
tion in 1945.
Calcined dolomite was initially used by Marine Products, followed
by Kaiser in 1942, and was substituted for oyster shells as the precipi-
tating agent in 1947 at the Newark operation. Since then, the use of
dolomite has increased concurrently with that of magnesia. In 1964,
the manufacture of magnesia used about 500,000 tons of California
dolomite.
Dolomite, which now accounts for approximately one-half of the
magnesia produced in California is generally restricted in occurrence.
The dolomite used at Newark and Moss Landing is mined from sep-
arate quarries in the Gabilan Range between Salinas and Hollister.
These deposits consist of large roof pendants of crystalline dolomite
(with some limestone) in Paleozoic(?) complexes. (Eefer to the
section on "Limestone, dolomite, and lime products" for description
of dolomite resources in California.)
Magnesite has three major tyj^es of occurrence : (1) as large crystal-
line bodies in dolomite, (2) within shear zones and veins, and as
MINERAL AND WATER RESOURCES OF CALIFORNIA 241
replacement-like bodies in serpentine, and (3) tis sedimentary del>osit^s
associated Avitli playa lake beds. The larger magnesite dej^osits of
the world, including those of Chewelah, Washington, and Gabbs,
Nevada, and those in Austria and Manchuria, are of the dolomite
replai^cment type. The magnesite of these deposits is crystalline, as
constrasted with the cryptocrystalline or "amorphous*' variety, char-
acteristic of deposits associated with serj)ent.ine and with lake
sediments.
Most of the magnesite deposits in California are aas<jc.iated with ser-
pentine and (K'cur in the (^alifoniia Coast Ranges and in the western
foothills of the Sierra Nevada. Many of the deposits and mines have
been discussed l>riefly by l^-adley (1925, p. 41-140), and othei-s by
Hess (1908) , and Gale ( 1914) . The Red Mountain magnesite district,
on the border of Santa Clara and Stanislaus Counties, is a typical
replacement deposit which has l)een studed in detail by Bodenlos
(1950).
Certain terrestrial brines are important sources of magnesium chem-
icals. The l)est known are the magnesium -calcium chloride brines
of Michigan, Ohio and West Virginia. In California, the brine of
Bristol Lake, San Bernardino County belongs to this claas; but mag-
nesium compounds are not recovered from it.
The manufacturing process is fundamentally alike in the large
operations of Food Machinery and Chemical Corp., Kaiser, and Marine
Magnesium. Sea water is treated with a regulated amount of slaked
dolomite or lime to precipitate the soluble bicarbonates as calcium car-
bonate. At the Food Machinery and Cliemical Corp. plant, which
uses concentrated salt water bittern, the sulfate must Hrst be removed
by combining the bittern with calcium chloride. Then, the calcium
carbonate is removed by thickening and the '"purified" sea water is
combined with either dry or slaked calcined dolomite. The resulting
magnesium hydroxide is washed witli fresh water to remove calcium
chloride and thickened in a counter-current system to concentrate the
sluri*y of magnesium hydroxide. The thickened magnesium hydrox-
ide is filtered and fed into kilns for conversion to caustic-calcined
or dead-burned magnesia.
Synthetic magnesia (produced from sources other than brucite,
magnesite, or magnesium silicate ores) supplies an increasing portion
of the total domestic supply of both dead-burned and caustic-calcined
magnesia. In 1947, synthetic magnesia accounted for about '^0 per-
cent of the usage; by 195G, it increased to 5t) percent: and in 1968 the
figure was 74 percent. Production from well brines, tlolomite, and/or
raw sea water, and sea water bittern in 1963 accounted for about 48
percent of the caustic-calcined magnesia sold or used, and for aboul
79 percent of the refractory magnesia sold or used by producers in the
United States. Because the economically useful supply of natural
magnesite and brucite is exhaustible, the long-term trend will continue
to favor production of synthetic magnesia.
California's 1963 production of synthetic magnesia produced en-
tirely from dolomite and sea water, accounted for about 18 percent of
the total United States production of refractory and caustic-calcined
magnesia from all sources (see fig. 36) .
(California's production increased from 1950 to 1961 but has fallen
off slightly since then (see table 26). This growth is mainly attribu-
242
MINERAL AND WATER RESOURCES OF CALIFORNIA
1000
z
o
o
X
C/)
o
o
o
BOO
600
400
200
Total
dol omi te , sea water
and br ines
From magnesJte, brucite, and
minor magnesium silicate ores
1947
1949
1951
1953
1955
1957
1959
1961
1963
Figure 36. Domestic production of magnesia from ores and brines in the United
States, 1947-63 (U.S. Bureau of Mines Minerals Yearbook, 1956 and 1963
editions).
table to the increasing volume of refractory magnesia, with the ratio
of caustic-calcined to refractory magnesia (produced in California)
ranging from a low of 0.04 in 1950 through 0.26 (1955) ; 0.15 (1960) ;
to 0.29 in 1963. Future production will probably reflect the general
increasing demand for basic refractories and the use of various mag-
nesium compounds with our expanding population.
The resources of dolomite in southern California are great, especial-
ly along the north part of the San Bernardino Mountains and in the
Victorville area. In northern California, however, the known com-
mercial dolomite deposits are presently in use except for the much
less accessible Sierran foothill dolomite. The enormous amount of
dolomite rock in the eastern Mojave Desert is, at present, quite re-
mote.
A source of magnesia could result from combining the dolomite re-
sources of San Bernardino County with sea water. Presently, Kaiser's
Steel plant at Fontana and various portland cement plants are the
prime users of magnesia in southern California. Should the market
for magnesium compounds improve considerably with additional heavy
industry, this potential may some day be realized.
Selected References
Bain, G. W., 1924, Types of magnesite deposits and their origin : Econ. Geology,
y. 19, p. 412-433.
Bradley, W. W., 1925, Magnesite in California : California State Min. Bur. Bull.
79, 147 p.
Bodenlos, A. J., 1950, Geology of the Red Mountain magnesite district, Santa
Clara and Stanislaus Counties, California : California Jour. Mines and Geology,
V. 46, p. 223-278.
MINERAL AND WATER RESOURCES OF CALIFORNIA 243
Bowen, O. E., Jr., 195i, Geology and mineral resources of Barstow quadrangle,
San Bernardino County, California : California Div. Mines Bull. 165, p. 170-
172.
California State Mining Bureau, 1906, magnesite, in Structural and industrial
minerals of California : California State Min. Bur. Bull. 38, p. 327-334.
Comstock, H. B., 1963, Magnesium and magnesium compounds — A materials
survey : U.S. Bur. Mines Inf. Cire. 8,201.
Davis, R. E., 1957, Magnesium resources of the United States — A geologic sum-
mary and annotated bibliography to 1953: U.S. Geol. Survey Bull. 1,019-E,
p. 373-515.
Gale, H. S., 1912, Late developments of magnesite deposits in California and
Nevada : U.S. Geol. Survey Bull. 540, p. 483-520.
Hess, F. L., 1908, The magnesite deposits of California : U.S. Geol. Survey Bull.
355, 67 p.
Ladoo, R. B., and Myers, W. M., 1951, Nonmetallie minerals: New York, Mc-
Graw-Hill Book Co., 2d ed., p. 296-311.
Manning, P. D. V., 1943, Magnesium — its sources, methods of reduction, and
commercial applications : Min. and Met., v. 24, no. 440, p. 346-348.
Perry, J. B., and Kirwan, G. M., 1942, The Bald Eagle magnesite mine, Cali-
fornia : Am. Inst. Mining Metall. Engineers Trans., v. 148, p. 35-50.
Pit and Quarry, 1931 (Nov. 18), California rotary-kiln lime plant uses oyster
shells as raw material : Pit and Quarry, v. 23, no. 4, p. 22-24, 43.
Rubey, W. W., and Callaghan, Eugene, 1936, Magnesite and brucite, in Hewett,
D. F., and others, Mineral resources of the region around Boulder Dam : U.S.
Geol. Survey BuU. 871, p. 114^144.
Seaton, M. Y., 1942, Production and properties of the commercial magnesias : Am.
Inst. Mining Metall. Engineers Trans., v. 148, p. 11-31.
Traufifer, W. E., 1938 (May), Lime, gypsum, and magnesite produced from sea
water and shells at new plant in California : Pit and Quarry, v. 30, no. 11, p.
43-^1.
Ver Planck, W. E., 1957, Magnesium and magnesium compounds, in Mineral com-
modities of California : California Div. Mines and Geology Bull. 176, p. 313-323.
Vitaliano, C. J., 1950, Needles magnetite deposit, San Bernardino County, Cali-
fornia : California Jour. Mines and Geology, v. 46, p. 357-372.
Wicken, O. M., 1960, Magnesite and related minerals, in industrial minerals and
rocks : Am. Inst. Mining Metall, and Petroleum Engineers, p. 533-544.
MANGANESE
(By F. F. Davis, California Division of Mines and Geology, San Francisco, Calif.,
and D. F. Hewett, U.S. Geological Survey, Menlo Park, Calif.)
Manganese plays an extremely important role in the metallurgical
technology of the modern steel age. It is used for pig iron and in a
series of ferrous alloys used in steel-making. The principal alloys
are ferromanganese, spiegeleisen, silico-manganese, and silicospiegel.
Manganese from these alloys serves to remove free oxygen and sulfur
in the melt, increases the strength and hardness of steel, and imparts
a mobility which permits the steel to be rolled and forged more easily.
Elemental manganese metal, 99.9 percent pure, is now produced elec-
trolytically from an acid solution of oxide ores. The high purity of
this product makes it especially useful for making stainless steel,
alloy steels, and manganese alloys of the non-ferrous metals copper,
zinc, aluminum, magnesium, nickel, tin, and lead. The chemical in-
dustry is an important but relatively small consumer of manganese
ore for such products as dry cell batteries, paints, varnishes, ceramics,
chemicals, and miscellaneous items. About 96 percent of manganese
used in the United States is consumed in the metal industries, 2i/| per-
cent is used in dry cell batteries and the rest is used in a variety of
chemical industries.
244 MINERAL AND WATER RESOURCES OF CALIFORNIA
Although the United States is the principal consumer of manganese
ores, consuming some 1,840,000 tons in 1963, its deposits of high-
grade metallurgical ores, containing over 40 percent manganese, are
extremely small, and domestic production rarely has exceeded 10 per-
cent of consumption. In 1963, domestic production was only 10,622
short tons and general imports were 2,093,473 short tons.
Although magmatic solutions are the primary source of manganese,
usually the primary manganese minerals are not concentrated suf-
ficiently to form ore (Jenkins and others, 1943). Most of the large
ore deposits throughout the world, liowever, are associated with sedi-
mentary rocks ; in others, minerals are principally oxides of secondary
origin. Some of the hydrothermal and sedimentary deposits have
been altered to manganese silicates. Because the silicates do not
constitute ore, only the oxidized portions of the metamorphic deposits
are mined.
The Indians found and utilized manganese deposits in eastern and
southeastern California as a source of face paint in prehistoric times.
Gold seekers were probably the first white men to note manganese
minerals in California, since a deposit near Sonora in the heart of the
gold country was reported in 1857. The first production came from
San Francisco Bay area where 200 short tons of manganese-bearing
rock was mined from Red Rock Island in 1866.
The Ladd mine in San Joaquin County was discovered in 1867 and
produced ore regularly on a small scale until 1903. Production from
California mines was negligible until World War I. Between 1915
and 1921 inclusive, about 75,000 short tons of ore were produced.
During this periocl more than 300 new manganese prospects were
opened, and about one-third of them produced ore, much of it below
peace-time specifications (Jenkins, 1943). Mining activity centered
in the Coast Ranges, where the principal producing mines were the
Ladd, Buckeye, and Thomas. Two mines, the Braito and the Mount
Hough, at the north end of the Sierra Nevada, and mines in the
Arlington and Paymaster districts in the desert of southeastern Cali-
fornia also contributed substantially to the total production.
Mine production again became sporadic between 1922 and 1940,
but increased in 1941, as submarine warfare reduced foreign supply.
In 1943, a dry concentrating plant was built near Patterson to process
ore from the Buckeye mine for use in dry cell batteries. Several new
deposits, sucli as the Blue Jay and the Trout Creek, were discovered in
Trinity County and were the sources of high-grade, direct shipping
ore. The Kaiser Steel Plant, erected at Fontana in 1943, provided an
additional outlet for southeastern California, so that production in-
creased from the manganese deposits in San Bernardino County and
the Arlington and Langdon districts of Riverside County. The price
of manganese ore declined after World War II, and only a token
production of ore was reported from 1946 to 1951.
During the Korean War period battery-grade ore was produced and
milled at the Ladd mine from 1951 until the end of 1954 and in 1952
the LT.S. Government established strategic mineral stockpiles in Ari-
zona and New Mexico to encourage the production of low-grade (15
to 40 percent Mn) domestic manganese ore. Important contributors
to this program were the Pioneer (Whedon) mine. Imperial County;
MINERAL AND WATER RESOURCES OF CALIFORNIA 245
Blackjack mine, Riverside County; and the Big Reef and Logan
mines, San Bernardino County. Concentrators were established at
Poe's siding to serve the mines in central San Bernardino County; at
Inca and Tasco siding to treat low-grade ores from the Arlington
district, Rivereide County ; and at Ripley to treat ore from Imperial
County. This program ended in 1959, and all California manganese
mines closed.
Except in wartime, there is little inducement for the capital invest-
ment necessary to develop the large, low-grade deposits known in the
United States. During 1954 when the government was accumulating
a stockpile of this strategic mineral material, shipments of manganese
ore from all domestic mines reached 206,128 short tons.
California manganese mines yielded an all-time }>eak production
of 37,747 short tons valued at $1,543,949 in 1954. This output in-
cluded ores ranging from 15 to 50 percent manganese. A token pro-
duction of ore (battery grade) was made in 1962 and none in 1963.
Total production from Califronia deposits between 1866 and 1964 was
320,205 short tons valued at $12,784,533.
Occurrences in California
The California deposits as shown in figure 37, lie chiefly in four
geologic provinces within which they are concentrated in several rock
or formation units :
1. Most of the unmetamorphosed deposits of sedimentary origin lie
in the Coast Ranges in a belt that extends from Humboldt to Santa
Barbara Counties. The deposits occur in chert of the Franciscan
Formation (Jurassic and Cretaceous) which is widely exposed. The
explored ore bodies are lenses of carbonate which range in width from
3 to 8 feet and extend several hundred feet along the outcrop.
The rocks of the Franciscan Formation commonly are folded and
faulted so that the ore zones now dip steeply. The primary minerals
are manganese carbonate and manganiferous opal, which weather to
high-grade "black oxide"' ore. Oxidation extends to depths of as
much as 200 feet below the surface. It is believed that the silica and
manganese were discharged by submarine springs or volcanos into
ocean basins of restricted circulation, where they formed chert and
managanese sediments (Jenkins, and others, 1943). Principal mines
are the Ladd, Buckeye, Foster Mountain, Thomas Mountain, and
Blue Jay.
2. Metamorphosed sedimentary manganese deposits are widespread
throughout the Sierra Xevada and are chiefly in rocks of the Calaveras
Formation (Upper Paleozoic) and Amador Group (Jurassic). The
depth of oxidation is generally very shallow, and most of the deposits
are currently of little economic importance. Representative mines
are the Braito and Mount Hough in Plumas County.
3. In the Klamath Mountains of northern California, the manganese
host rocks are both metamorphic and metasedimentary, ranging from
Paleozoic to Jurassic in age. The depth of oxidation in these bedded
deposits is shallow, and little ore has been produced.
4. At numerous localities in the Mojave Desert region of south-
eastern California, hypogene veins of manganese oxides with calcite
246
MINERAL AND WATER RESOURCES OF CALIFORNIA
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39
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\
d.ENN ;■ Bl.lfrE AV' ^ERRA
EX PLANAT I ON
Principal manganese nines
•
Ove r 15. 000 tons
1. Ladd 4. Blackjack (Arlington)
2. ■liedon( P ioneer ) 5. Langdon
3. Buckeye 6. Ne» Deal (0*1 Hole)
1 000 to 15.000 tons
A
1 tot 000 t ons
PRODUCTION
-^, lake; \Vij V! *.ic*<<\ ^\ •
A \.
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MOJAVE
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Figure 37. Principal manganese mines in California.
and barite have formed in fissures that cut fanglomerate and volcanic
rocks of Tertiary age, and older quartz porphyry. Most of the deposits
consist of brecciated rocks cemented, impregnated, and partly replaced
by manganese oxide, principally a hard oxide similar to psilomelane.
The average manganese content of the deposits mined is from 15 to
30 percent. The hard oxide can be hand-sorted in some places to give
a product containing 40 to 45 percent of manganese (Jenkins, 1943).
Principal mines are the Whedon (Pioneer), Blackjack, New Deal,
Langdon, Logan and Big Reef.
Recent work shows that manganese oxides also occur (a) in traver-
tine aprons near hot springs, either uniformly distributed through
MINERAL AND WATER RESOURCES OF CALIFORNIA 247
the calcium carbonate or as layers of manganese oxide alternating
with layers of calcium carbonate; and (b) as layers in stratified sedi-
mentary rocks. The best evidence for a genetic relationship between^
hypogene veins and stratified deposits is based on the presence in the
stratified deposits of minor metals such as tungsten, and on the areal
distribution of the deposits (Hewett and others, 1963) .
The total manganese ore produced in California from 1866 to 1964
inclusive, is about equal to 16 percent of the current (1965) annual
consumption in the United States. Most of the ore produced from
1869 to 1954 came from sedimentary deposits in the Coast Ranges.
During the decade 1954-1964, practically all the ore produced has
come from the hypogene vein deposits of southeastern California.
Even though much is known about the number and distribution of
the manganese deposits in California, there is little information about
the ore reserves. No bodies of high-grade shipping ore or bodies of
moderate grade concentrating ore which can be mined and sold at
competitive prices are known. Some deposits in the Coast Ranges and
in the desert provinces could no doubt produce small quantities of ore
at premium prices, but the size of these deposits is undetermined.
Additional prospecting during periods of high prices probably will
disclose a number of new small deposits in these provinces.
Because many California deposits contain siliceous manganese
minerals, some long-range potential for these refractory materials may
exist if a satisfactory process can be developed for the recovery of the
manganese. No data are available on the size and extent of the
siliceous deposits.
Selected Refekences
Davis, F. F., 1957, Manganese, in mineral commodities of California : California
Div. Mines and Geology Bull. 176, p. 325-339.
De Huff, G. L., 1960, Mineral facts and problems, manganese : U.S. Bur. Mines
Bull. 585, p. 493-510.
Hewett, D. F., and Pardee, J. T., 1933. Manganese in western hydrothermal ore
deposits, in Ore deposits of the Western States (Lindgren volume) : Am.
Inst. Mining and Metall. Engineers, p. 488-491.
Hewett, D. F., and Fleischer, M., 1960, Deposits of manganese oxides; Econ.
Geology, v. 55, no. 1, p. 1-55.
Hewett, D. F., Chesterman, C. W., and Troxel, B. W., 1961, Tephroite in Cali-
fornia manganese deposits : Econ. Geology, v. 56, no. 1, p. 39--59.
Hewett, D. F., Fleischer, M., and Conklin, N., 1963, Deposits of manganese
oxides, supplement : Econ. Geology, v. 58, no. 1, p. 1-51.
Jenkins, O. P., and others. 1943. Manganese in California : California Div.
Mines Bull. 125, p. 1-385.
Trask, P. D., 1950. Geologic description of the manganese deposits of California :
California Div. Mines Bull. 152, p. 1-378.
MERCURY
(By F. F. Davis, California Division of Mines and Geology, San Francisco,
Calif., and E. H. Bailey, U.S. Geological Survey, Menlo Park, Calif.)
Mercury, the silver-colored liquid metal commonly known as quick-
silver, possesses physical and chemical properties which make it ex-
tremely valuable for many industrial uses, in most of which no
suitable substitutes are known. California is, and has been, the
source of most of the mercury produced in the United States. Some
of the properties of mercury and the industrial uses that result from
248 MINERAL AND WATER RESOURCES OF CALIFORNIA (
these properties are listed below, and the proportion of the total
domestic consumption used in each category during the past 5 years
is shown in parentheses :
1. High electrical conducti\dty : switches, relay tubes, rectifiers,
oscillators, batteries, lamps, signs, and other electrical devices
(22 percent),
2. High specific gravity and uniform rate of expansion: in-
dustrial and control instruments such as weight ometers, pres-
sure gauges, analytical apparatus, flow meters, pendulums, pumps,
gyrocompasses, clutches, barometers, thermometers, and heat-
control devices (16 percent) .
3. Amalgamation with other metals and fluidity : mercury elec-
trolytic cells used in the production of chlorine and caustic soda
(11 percent).
4. Poisonous character of its compounds: seed disinfectants,
turf fungicides, and plant germicides (5 percent) ; mold and mil-
dew inhibitors and anti-fouling paints (8 percent) ; mercury salts
and pharmaceuticals (5 percent) .
5. Combinations of physical and chemical properties : hundreds
of other uses, such as dental inlays and castings, power production,
munitions industry, in the plup and paper industry, in the re-
covery of gold, in general laboratories, and in atomic energy
applications (33 percent) ,
Since satisfactory substitutes are generally unavailable, mercury
has been considered an essential commodity both for civilian and mili-
tary purposes, and it is generally included in lists of strategic materials
during times of national emergency.
*— Annual world production in the 1955-1964 period averaged about
235,000 flasks, and the United States economy required each year about
60,000 flasks, or about one-fourth of the world supply. Although the
United States has in the last hundred years produced nearly as much
mercury as it has used, the domestic production in the recent 10-year
period has been only 48 percent of consumption and in 1964 amounted
to only 21 percent. For the past 50 years the gap between supply and
demand in the United States has been bridged by imports from Spain,
Italy, Mexico, and Yugoslavia, where mercury can be recovered some-
what more cheaply than at most domestic mines. As Spain and Italy
have dominated world supplies in the past, they have been able to
control the price of mercury simply by oversupplying or withholding
stocks from the market, often to the detriment of domestic producers.
In wartime, however, foreign sources are less accessible, and domestic
mercury mines have been temporarily stimulated by price increases;
concurrently foreign stocks accumulate, and, with the cessation of
hostilities, the large quantity of mercury that becomes available has
resulted in greatly depressed prices. This has lead to wider price
fluctuations for mercury than for most other commodities and has
given the mercury mining industry the reputation of being one of high
risk.
Beginning in early 1964, a new and more liealthy trend in the mer-
cury mining industry was initiated when the pric€ began to rise as a
result of normal peace-time demand exceeding the world's production.
The upward trend in price began from a level of about $225 a flask
and continued into mid-1965, when it exceeded $700 a flask. This
MINERAL AND WATER RESOURCES OF CALIFORNIA 249
drastic increase generated a renewed interest in mercury mining and
started a scramble to lease properties and put them into production.
However, no immediate <^reat increase in production can be expected,
because most of the California mines were inoperative prior to the
price increase and must not only be rehabilitated but must also find
new ore to exploit. ^
Cinnabar, HgS, the bright-red stable form of mercury sulfide, is
the principal mercury ore mineral. Metacinnabar, HgS, the black
sulfide of mercury, and silvery metallic mercury are found in the ore
of some mines, but only in a few are they importiant ore minerals.
Other very rare mercury minerals occasionally found in California
are calomel, HgCl; eglestonite, HgCl204; and montroydite, HgO.
Mercury ores contain few other metallic minerals. Pyrite or marcasite
is generally present in small amounts, and stibnite, though commonly
absent, is abundant in a few deposits. The principal gangue minerals
are quartz, opal, chalcedony, calcite, dolomite, and magnesite. Liquid
or solid hydrocarbons are present in minor amounts in many deposits.
None of these minerals normally is abundant enough in California
mines to require special treatment in ore extraction, but pyrite or stib-
nite, if very abundant, can introduce difficulties.
Mercury deposits are found chiefly in regions of extensive Tertiary
or Quaternary volcanic and tectonic activity. The deposits are
classed as epithermal, being fonned by the deposition of ore minerals
from aqueous solutions at relatively low temperatures and a,t shallow
depths. Their close association with hot springs is shown by the
presence of cinnabar at Coso Hot Springs in Inyo County, The Gey-
sers in Sonoma County, the Sulphur Bank mine in Lake County, and
at Amadee Springs in Lassen Coimty, in all of which cinnabar is
either being deposited or was very recently deposited. However, in
most districts the mercury was deposited during an earlier period, the
hot springs have ceased flowing, and any surficial spring deposits that
were once present have been removed by erosion leaving the mercury-
bearmg roots of the spring systems.
Mercury ore bodies commonly are small, irregular, and more errati-
cally distributed than are the ore bodies of other minerals. Cinnabar,
perhaps with some metacinnabar or native mercury, fills fractures and
voids or has replaced the host rock. Many ore bodies have been formed
by the concentration of primary minerals in openings in porous or
broken rocks, especially where they are overlain by relatively imper-
vious rocks. Others that are equally as large and rich are the result of
replacement of silica-carbonate rock, which is a hard brittle rock
formed by the hydrothermal alteration of serpentine to a mixture of
quartz or opal and a carbonate that is generally magnesite.
More than 50 percent of the larger mercury deposits in California
occur in this silica-carbonate rock, with the cinnabar in some deposits
replacing the rock and in others just filling fractures. The silica-
carbonate rock is associated with so many deposits it is commonly
called "quicksilver rock," but it is much more widespread than the ore
and is not very useful as a guide in prospecting. Other mercury de-
posits in California occur in highly deformed sedimentary rocks of
the Franciscan Formation, of Jurassic and Cretaceous age, with which
the serpentine and silica-carbonate rock are associated. Still others
6r-l©4 O — 66^pt. I 17
250 MINERAL AND WATER RESOURCES OF CALIFORNIA
occur ill the less deformed sedimentary rocks of the Knoxville, Pas-
kenta, Chico, and Panoche Formations of simihir ao;e. Tertiary sedi-
mentary and volcanic rocks locally contain major deposits in Cali-
fornia, as do also Quaternary volcanic rocks. Even a few small Recent
placer deposits have been successfully exploited.
The history of the discovery and development of these deposits is as
long and fully as colorful as the saga of California gold mining. In
prehistoric time, cinnabar was used as a source of paint for war and
tribal ceremonials by the California Indians, and they are known to
have mined it at the site of the New Almaden mine, as well as elsewhere
in the State, long before civilization reached California. The New
Almaden deposit was rediscovered by white men in 1824, began pro-
ducing in 1846, reached its peak in 1865 when nearly 50,000 flasks
were recovered, and has been in production, though at a declining rate,
almost ever since then. It is the oldest metal mine in California, and
the first mercury deposit discovered in North America. In 1853 the
deposit of the New Idria mine in San Benito County was discovered.
It, too, has been mined almost continuously since its discovery, and,
in 1965, was the most productive mercury deposit in the United States.
As the demand for mercury for amalgamation increased following
the gold rush of the 1850's, exploration for mercury expanded north-
ward in the Coast Ranges, and soon important new discoveries were
made at Knoxville, Oat Hill, and Aetna Springs in Napa County ; at
Sulphur Bank and near Wilbur Springs in Lake County ; and in the
Mayacmas district of Lake and Sonoma Counties. During the 1860's,
hydraulic mining for gold on a grand scale, and the discovery of
the Comstock lode in Nevada, led to still greater demand for mercury,
and exploration southward from New Almaden led to the discovery
of new mercury deposits in Santa Barbara and San Luis Obispo
Counties. Many of the mines reached their peak of production in
the mid-1870's, which were also peak years for the State as a whole.
The Sawyer decision of 1884 adversely affected the hydraulic mines
and curtailed the need for mercury. As a result, mercury production
declined almost continuously for the next 37 years and many mines
closed. All the major deposits were discovered by 1895, although
a rich short-lived open-pit mine was developed in the Emerald Lake
district of San Mateo County in 1955, and a rich new ore body was
found at the Buena Vista mine in San Luis Obispo County in 1957.
Since 1914, mercury production has been encouraged by five sepa-
rate stimuli : the strategic demands of World War I, the industrial
expansion of the late 1920's, the demands of World War II, the
Korean War and Governmental aids of the late 1950's, and the indus-
trial demands of 1964-1965. During each of these periods, the in-
creased price led to renewed activity that resulted in an increase in pro-
duction, but this came largely from deposits that had been known for
many years. If history is repeated, we may expect many of the Cali-
fornia mines now regarded as "worked out" to be successfully
reactivated.
The worldwide unit of trade in mercury is the flask — a cast iron
or steel cylinder about 5 inches in diameter and 12 inches long con-
taining 76 pounds of liquid mercury. Total world production
amounts to about 20 million flasks, and United States production is a
little less than 314 million flasks. Deposits in California have yielded
MINERAL AND WATER RESOURCES OF CALIFORNIA 251
about 85 percent of the domestic production, or about 2% million
flasks valued at about $200 million. This value is exceeded among
metallic mineral producers in California only by the value of the
output of gold and copper mines-
Occurrences in California
The highly productive mercury deposits of California lie in a belt
extending through the California Coast Ranges from central Lake
Coimty southward to Santa Barbara County. It contains the Na-
tion's eight most productive mines, dominated by the ^reat New Ai-
maden mine with a production record of over one million flasks, and
the New Indria mine, which has yielded more than half a million
flasks. Also included are about a hundred other productive mercury
mines, many prospects, and the major mercury reserves of the United
States. These are clustered in 21 districts, shown on figure 38, most
of which contain one, or at most two, prominent deposits and numerous
smaller ones, though an exception is provided by the Mayacmas dis-
trict, in Napa, Sonoma, and Lake Counties, which contains several
major deposits.
One of the State's principal mercury mines, the Altoona in north-
eastern Trinity County, is in the Klamath Mountains province. An-
other less productive mine, the Walibu, is in the Tehachapi district at
the southern end of the Sierra Nevada province. Relatively small
amounts of mercury also have been obtained from outside the Coast
Ranges province in the Patrick Creek and Beaver Creek districts in
the Klamath Mountains, the Coso district in the Great Basin province
of southwestern Inyo County, and the Tustin district of Orange
County in the Peninsular Ranges province.
The New Almaden mine, a few miles south of San Jose in Santa
Clara County, is the most productive mercury mine in North America
and provides a good example of ores in silica-carbonate rock. The
mine area is miderlain mostly by ^rayw.acke, shale, and greenstone
(altered mafic lavas) of the Franciscan Formation, and serpentine.
The dominant structure is a northwest-trending anticline whose south-
west limb has been highly sheared. Two major sills of serpentine
appear to have been intruded up the north limb, to have converged
near the crest, and to have continued down the southern flank. The
serpentine was hydrothermally altered, particularly along its margins,
to silica-carbonate rock. Cinnabar, the principal ore mineral, was
introduced along a series of narrow northeast-trending fractures and
replaced the silica-carbonate rock bordering them to form unusually
rich ore bodies. The most productive ore bodies were formed along
the margins of the two altered serpentine sills, and the largest was 200
feet wide, 15 feet thick, and extended 1,500 feet on the dip. Cobbed
ore mined during the first 15 years of recorded production averaged
more than 20 percent mercury, and the ore produced during the entire
productive history of the mine averaged only a little less than four
percent. The workings at the New Almaden mine reach a point 2,450
feet below the surface, making it the deepest mercury mine in the
world, but almost half of the ore was removed .above the 800-foot
level.
The New Idria mine, in San Benito County, ranks second in pro-
duction among mercury operations of North America and in 1965
252
MINERAL AND WATER RESOURCES OF CALIFORNIA
41°-
40°-
123° 122* 121°
F3jrRTPv*^-trAvt*r'-r«rrr" — 1---
( s I s K i(y o\u/— >J Y)
K-h.AMAXW ^( 1 o "> i
V > L I L '<- \ T ^
UNITED STATES PRODUCTION 1650-1964
3.306,586 FLASKS
TRINITY '
-L.2:
:AsCAb
_MOUNVAINfe_
""*"^~"^-' PLUMAS
40'"
— V \_ \ ^. >:
ENN f BU*E v.- SIERRA
^lo
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S'iw' ' -^ ^ >• TUOLUMNE
':so^»MA;,"X':""S4;,„,v_ „ ,-
>^ > ISOLANO' -h_-
PROPORTION BY STATES
\\8'
(IMfekiaC^
SALTON \ ^33°
Figure 38. Mercury districts in California.
was the leading producer. It provides an example of a major producer
having ore bodies in rocks otner than silica-carbonate or Franciscan
sedimentary rock, though both are present in the area. The major
structure in the New Idria district consists of a pluglike mass of
serpentine and Franciscan graywacke pushed up through shale and
sandstone of the Panoche Formation (Upper Cretaceous) and Terti-
ary sedimentary rocks. The margins of the plug are steep faults which
dip away from the central core, except in the New Idria mine area,
where the contact dips inward to form the New Idria thrust fault.
Beneath the New Idria thrust fault, the upper shales of the Panoche
are crumpled and overturned; in some places highly broken Fran-
ciscan sandstone and, in other places, serpentine lie above the fault.
MINERAL AND WATER RESOURCES OF CALIFORNIA 253
The ore bodies occur chiefly in altered and indurated Panoche rocks
beneath the thrust fault, and irregularities in the plane of the fault
have closely controlled zones of deposition. Cinnabar fills open spaces,
forming veins and stockworks, and rich ore formed where the fractur-
ing was most intensive. Some ore also occurs in the altered Franciscan
rocks and in silica-carbonate rock. Known ore extends in places
through a vertical range of more than 1,400 feet and a horizontal
span of about ten miles. One ore body was 300 feet long, 25 to 150
feet thick, and extended through a depth of 800 feet. This ore shoot
occupied a steep inverted trough at the intersection of the New Idria
thrust fault with a tear fault.
The other mines of the Coast Ranges are too numerous to be dis-
cussed individually here, but reports on essentially all of them have
been published (see references at the end of this article). Although
formed under similar geologic conditions, the deposits show marked
differences in the character, size, grade, and distribution of the ore
bodies largely because of the diversity of rocks in which they formed.
The relatively few mercury mines in California that are outside of
the Coast Ranges province are even less similar. The only large one
is the Altoona mine in the Klamath Mountains, which has yielded
about 35,000 flasks. Tlie mine is in porphyritic diorite and serpentine,
both of which are intensely altered and replaced by quartz and car-
bonate. Tliree major faults traverse the area, and cinnabar and some
native mercury form irregular ore bodies in and near the fault gouge.
Ore shoots average 5 feet in width, extend along the strike
100 to 300 feet, and down the dip for as much as 300 feet. The av-
erage grade has been about 1 percent mercury.
The Walibu (Cuddeback) mine, 10 miles northwest of Tehachapi in
Kern County, exploits the southernmost of several small mercury oc-
currences in the Sierra Nevada province. Here, mercury ore occurs
in a rhyolite dike which has intruded the granitic rocks of the Sierra
Nevada batholith. Cinnabar encrusts fracture walls, fills small brec-
cia veins, and is disseminated as minute crystals through the more
altered rhyolite.
Farther east, in the Great Basin Province, small amomits of mercury
have been obtained from Recent hot-spring deposits in the Coso dis-
trict of southwestern Inyo County. Tliese mercury deposits consist of
small irregular cinnabar veins in silicified and kaolinized tuff and
granite. Near Tustin, Orange County, cinnabar and native mercury
are associated with small veins of barite in country rock of Tertiary
sandstone.
One may expect that California will continue to provide most of the
mercury recovered in the United States. Although known and indi-
cated reserves are only sufficient to sustain production for a few
years, the history of the industry indicates that with the price of
mercury high enough to stimulate exploration, as it was in mid-1965,
new ore bodies will be sought and discovered. Although most of these
will be satellitic to known deposits, new exploration techniques in-
volving geochemical sampling, or the use of the recently developed
mercury detectors may be able to locate wholly new areas with suffi-
cient mercury concentration to be minable at the high prices likely to
prevail in the years to come.
254 MINERAL AND WATER RESOURCES OF CALIFORNIA
Selected References
Bailey, E. H., 1962, Mercury in tlie United States: U.S. Geol. Survey Mineral
Inv. Res. Map MR 30.
Bailey, E. H., and E>verliart, D. L., 1964, Geology and quicksilver deposits of the
New Almaden district : U.S. Geol. Survey Prof. Paper 360, 206 p.
Bailey, E. H.. and Smith, R. M., 1964, Mercury — its occurrence and economic
trends: U.S. Geol. Survey, Circ. 496, p. 1-11.
Davis, Fenelon F., 1957, Mercury, in Mineral commodities of California : Cali-
fornia Div. Mines and Geo. Bull. 176, p. 341-356.
Eckel, E. B., and Myers, W. B., 1946, Quicksilver deposit.s of the New Idria dis-
trict, San Benito and Fresno Counties, California : California Div. Mines
Rept. 42, p. 81-124.
Linn, R. K.. and Deitrich, W. F.. 1961, Mining and fumacing mercury ore at
the New Idria mine, San Benito County, California : U.S. Bur. Mines Inf.
Circ. 8,033, p. 6-13.
Pennington, J. W., 1959, Mercury — a materials survey : U.S. Bui-. Mines Inf.
Circ. 7,941, p. 11-27.
U.S. Bureau of Mines, 1965, Mercury potential of the United States : U.S. Bur.
Mines Inf. Circ. 8,252, p. 1-376.
Yates, R. G., and Hilpert, L. S., 1946, Quicksilver deposits of eastern Mayacmas
district. Lake and Napa Counties, California : California Div. Mines Rept. 42,
p. 231-286.
MICA
(Muscovite, biotite, and vermiculite)
(By F. G. Lesure, U.S. Geological Survey, Washington, D.O.)
Moderate amounts of muscovite and small amounts of biotite and
vermiculite have been mined in California since 1902. Most of the
muscovite has come from six deposits (nos. 7, 11, 12, 15, 19, and 24,
table 27), the biotite from one (no. 6, table 27), and the vermiculite
from one (no. 22, table 27) . The total production of muscovite, 1902-
1951, is valued at more than $198,574.
The principal mica minerals are muscovite (white mica), biotite
(black mica), and phlogopite (amber mica). All have a perfect
basal cleavage and form crystals that can be split into thin sheets
having various degrees of transparency, toughness, flexibility, and
elasticity. The micas are common minerals, but only muscovite is
mined extensively in the United States. Vermiculite is a micaceous
mineral derived mainly from the chemical alteration of biotite and
chlorite.
Two types of mica are sold : (1) sheet mica which must be relatively
flat, free from most defects, and be large enough so that it can be
cut in pieces 1 square inch or larger; and (2) scrap mica which is all
mica that does not meet sheet mica specifications ; it is generally ground
to a powder. Small sheets of untrimmed mica of poorer quality that
can be punched or trimmed into disks 1 inch or larger in diameter are
classified as punch mica and are included in the general term sheet
mica. Sheet muscovite is an important insulating material in the
electronic and electrical industries. Built-up mica made from very
thin sheets, and reconstituted mica made from scrap can be substituted
for larger sheet mica for some uses. The principal uses of scrap
mica are in the roofing, wall paper, rubber, paint, and other industries.
Vermiculite has little value in its natural form but when expanded
by heat it forms a low density product with excellent thermal and
MINERAL AND WATER RESOURCES OF CALIFORNIA 255
acoustic insulation properties. It is used as a light-weight aggregate
in concrete and plaster, as an extender or filler in paper, plastics, and
paint, as a packing material, and as a soil conditioner.
Sheet-quality muscovite is obtained from large crystals scattered
throughout unzoned pegmatites or concentrated in certain units of
zoned pegmatites. The value of sheet mica depends on the color, size,
structure, and quality of the natural crj^stals. Details of the prepara-
tion and classification of mica and trade practices of the industry are
too elaborate to discuss here. The best published reference is by C. M.
Rajgarhia (1951), whose knowledge of the subject was based on a
lifetime of experience in the sheet mica business in India, which sup-
plies most of the world's mica. Excellent references written in the
United States are by Skow (1962), Montague (1960), Jahns and
Lancaster ( 1950) , and Wierum and others ( 1938) .
The discontinuous nature of most mica concentrations, the great
range of quality of material, the expense of mining, and the large
amount of hand labor needed for preparation generally limit sheet
mica mining to periods of very high prices. Since the end of the
Government purchasing program in June 1962, little sheet mica has
been mined in the United States. Most of the sheet muscovite used
in the United States comes from India and Brazil and the sheet and
scrap phlogopite comes from Canada and the Malagasy Republic.
Most of the recent domestic production of sheet mica has come from
North Carolina, New Hampshire, and South Dakota. Only a few
hundred pounds of poorer quality sheet mica have been produced in
California, mostly from the Mount Alamo deposit, Ventura County.
No deposits of high-quality sheet mica are known to occur in the State.
Large quantities of fabricated sheet mica for electronic equipment
are shipped into 'California from eastern manufacturers.
Many pegmatite deposits contain only scrap mica, and a large
amount of scrap is produced during the mining, trimming, and fabri-
cating of sheet mica. Scrap mica is also recovered from muscovite
and biotite schists and as a byproduct from the mining of feldspar and
clay. Such scrap mica is generally referred to as flake mica. Most
of the mica mined in the Ignited States is scrap mica and all the
resources and most of the production of mica in California has been
scrap quality. Scrap mica mined outside the State was ground by the
Sunshine Mica Co. in Los Angeles County in 1963 (Davis, 1964, p.
204) . A new mill in Mariposa County will process mica schist using a
modification of a method for mica recovery developed by the U.S.
Bureau of Mines (Browning and Bennett, 1965) .
California has several plants that expand vermiculite ores shipped
into the State. California Zonolite Co. operates plants in Sacramento
and Los Angeles Counties using ore from Montana, and La Habra
Products, Inc. operates a plant in Orange County using South African
ore (Davis, 1964, p. 185) . No vermiculite has been mined in the State
in recent years.
The selling price of mica can range from only a few cents per pound
for punch or scrap to many dollars a pound for large sheets of the
best quality. In 1958 the price schedule under the U.S. Government
purchase program for sheet mica of superior quality (termed "good,
stained or better") ranged from $17.70 per pound for the smallest
256
MINERAL AND WATER RESOURCES OF CALIFORNIA
sizes to $70 per pound for the large sizes. Prices in 1958 for India
mica of similar quality ranged from $2.50 to $37 per pound (Montague,
1960, table 8) . In 1965 prices for sheet mica as quoted in the Engine-
ering and Mining Journal Metals and Markets ranged from $0.07
a pound for sheets II/2 inches across to $8.00 a pound for sheets 8
inches or more across. Scrap mica is valued at the mine at $20 to
$30 per short ton. Most of the buyers of mica are in the eastern
United States. Prices for vermiculite ore, short ton, f.o.b. Montana,
are listed by Engineering and Mining Journal Metals and Markets as
$9.50 to $18.00, and South African ore, crude, c.i.f. Atlantic ports,
$27.85 to $38.50.
Occurrences in Californta
Mica-bearing rocks are widespread in California. Mica schist is
found in parts of the Klamath Mountains, the Sierra Nevada, and the
mountain ranges and deserts of the southern part of the State. In
general, the mica schists that are mined are parts of extensive areas
of metamorphic rock and are available in large tonnages. Pegma-
tites containing muscovite are also widespread but are neither large
nor abundant. Sheet muscovite is rare or sparse in the pegmatites of
the Sierra Nevada, Great Basin, Mojave Desert, and Transverse
Ranges, and none is known in the pegmatites of the Peninsular Ranges
(Jahns, 1954, p. 48). Scrap muscovite is common in the pegmatites
of the Great Basin and rare to sparse in the pegmatites of the Sierra
Nevada, Mojave Desert, Transverse Ranges, and Peninsular Ranges
(Jahns, 1954, p. 48) . The known mica deposits are listed in table 27
and the locations shown in figure 39. The most important deposit is
the Micatalc mine of Imperial County which has produced, since
1929, several tens of thousands of tons of flake mica from mica schist
(Wright, 1957, p. 359).
Table 27. — Mica and vermiculite occurrences in California
Index
No. on
fig. 39
Name
Reference
1
Tlnname'l OfMirrenw
Oesterling and Spurck, 1964b, p. 184.
2
.. do.
Tischler, 1964, p. 70.
3
Pacific
Wright, 1957, p. 359.
4
Brushy Canyon
Bowen and Gray, 1957, p. 212-213.
5
Ruth Hill
Logan and others, 1951, p. 511.
6
Pacific Grove
Wright, 1957, p. 359.
7
Death Valley Mica
Norman and Stewart, 1951, p. 103.
7a
Silver Lady Prospect
(L. A. Wright, written communication, 1965).
8
Lucky Betty -- - . -
Tucker and Sampson, 1931, p. 377-379.
9
Unnamed prospect
Oesterling and Spurck, 1964a, p. 179.
10
do
Do.
11
Hodge -.- . -
Bowen, 1954, p. 151-152.
12
DewilUbie
Bowen, 1954, p. 152-153.
12
12
Marshall and Davis
Marter-White
Bowen, 1954, p. 153-154.
Bowen, 1954, p. 154-158.
13
Snow White - .--.-.
Bowen, 1954, p. 158.
Oesterling and Spurck, 1962a, p. 179.
Do.
14
Unnamed occurrence.
15
Unnamed prospect --
16
Nora-Evalyn. _- -^- _ _ _
Gay and Hoffman, 1954, p. 676.
17
18
19
Apex, Dorothy Ann, and Mica 1
Independent American Mining Co
Mount Alamo
Do.
Do.
Sterrett, 1923, p. 48.
20
21
22
Unnamed occurrence
Carlsbad
Circle Group. .-
Oesterling and Spurck, 1964a, p. 179.
Weber, 1963, p. 79.
W'eber, 1963, p. 280-282.
23
Mica Gem
Weber, 1963, p. 193.
24
Micatalc
Henshaw, 1942, p. 195.
MINERAL AND WATER RESOURCES OF CALIFORNIA
257
EXPLANATION
▲
Muscov i te in pegma t i te
Muse ov i te in schist
B i ot i te from sand
O
V e r mic u li te
FiGiTRE 30. Mica in California (numbers refer to table 27) .
Selected References
Bowen, O. E., Jr. 1954. Geology and mineral deposits of Barstow quadrangle,
San Bernardino County, California : California Div. Mines Bull. 165, 208 p.
Bowen, O. E., Jr., and Gray, C. H. Jr., 1957. Mines and mineral deposits of Mari-
posa County, California : California Jour. Mines and Geology, v. 53, p. 35-343.
Browning, J. S., and Bennett, P. E., 1965, Flotation of California mica ore : U.S.
Bur. Mines Kept. Inv. RI-6668, 7 p.
Davis, L. E., 1964, The mineral industry of California in U.S. Bur. Mines Min-
erals Yearbook 1963, v. 3, Area Repts., p. 159-223.
Gay, E. E., Jr., and Hoffman, S. R., 1954, Mines and mineral deposits of Los
Angeles County, California : California Jour. Mines and Geology, v. 50, nos.
3-4, p. 467-709.
Henshaw, P. C, 1942, Geology and mineral deposits of the Cargo Muchacho Moun-
tains, Imperial County, California : California Jour. Mines and Geology, v.
38, no. 2, p. 147-196.
Jahns, R. H., and Lanscaster, F. W., 1950, Physical characteristics of commercial
sheet muscovite in the southeastern United States : U.S. Geol. Survey Prof.
Paper 225, 110 p.
258 MINERAL AND WATER RESOURCES OF CALIFORNIA
Jahns, R. H., 1964. Pegmatites of southern California in Jahns, R. H., ed., Geol-
ogy of southern California, Chap. VII, Mineralogy and petrology ; California
Div. Mines Bull. 170, p. 37-^50.
Logan, C. A., Braun, L. T., and Vernon, J. W., 1951, Mines and mineral resources
of Fresno County, California : California Jour. Mines and Geology, v. 47, no.
3, p. 485-552.
Montague, S. A., 1960, Mica, in Industrial minerals and rocks, 3d, ed. : Am. Inst.
Mining Metall. Petroleum Engineers, p. 551-566.
Norman, L. A., Jr., and Stewart, R. M., 1951, Mines and mineral resources of Inyo
County : California Jour. Mines and Geology, v. 47, no. 1, p. 17-223.
Oesterling, W. A., and Spurck, W. H., 19Ma, Eastern Mojave and Colorado deserts,
in Southern Pacific Company, Minerals for industry, Southern California,
summary of geological survey of 1955-1961, Volume III : San Francisco, p.
9^242.
Oesterling, W. A., and Spurck, W. H., 1964b, Klamath Mountains and Cascade
Range, in Southern Pacific Company, Minerals for industry. Northern Cali-
fornia, summary of geological survey of 1955-1961, Volume II : San Francisco,
p. 85-207.
Rajgarhia, Chand Mull, 1951, Mining, processing, and uses of Indian mica : New
York, McGraw-Hill Book Co., Inc., 388 p.
Sampson, R. J., and Tucker, W. B., 1942, Mineral resources of Imperial County :
California Jour. Mines and Geology, v. 38, no. 2, p. 105-145.
Skow, M. L., 1962, Mica, a materials survey: U.S. Bur. Mines Inf. Circ. IC-8,125,
240 p.
Sterrett, D. B., 1923, Mica deposits of the United States : U.S. Geol. Survey Bull.
740, 342 p.
Tischler, M. S., 1964, Northern Sierra Nevada, in Southern Pacific Company.
Minerals for industry, Northern California, s'lunmary of geological survey of
1955-1961, Volume II : San Francisco, p. 9-83.
Tucker, W. B., and Sampson, R. J., 1931, San Bernardino County: California
Jour. Mines and Geology, v. 27, p. 262-401.
Weber, F. H., Jr., 1963, Geology and mineral resources of San Diego County,
California : California Div. Mines County Rept. 3, 309 p.
Wierum, H. F., and others, 1938, The mica industry: U.S. Tariff Comm. Rept.
130, 2d. ser., 155 p.
Wright, L. A., 1950, Mica, in Mineral commodities of California : California
Div. Mines Bull. 156, p. 184-186.
, 1957, Mica, iii Wright, L. A., ed.. Mineral commodities of California :
California Div. Mines Bull. 176, p. 357-362.
MINOR METALS
(By M. C. Stinson, California Division of Mines and Geology, San Francisco,
Calif.)
"Minor metals" is a term that is loosely applied to a group of metals
each of which is uncommon and used in much smaller amounts than
the common base metals. Of the 8 minor metals described herein,
6 are recovered from residues collected in the smelting and refining
of sulfide ores. Gallium, germanium, indium, and thallium are re-
covered from zmc residues; selenium is recovered from copper resi-
dues; and rhenium is recovered from molybdenum residues. Cesium
and rubidium are recovered from pegmatite minerals.
Each of these metals probably has been obtained from ores mined
in California, but no data are available on their distribution or re-
covery by the custom smelters. Flue dusts and other residues from
American Smelting and Refining Company's smelters at Selby, Cali-
fornia, as well as from other western smelters, are treated at the Globe
Smelter in Denver where some of the minor metals are recovered and
refined.
MINERAL AND WATER RESOURCES OF CALIFORNIA 259
Cesium and Rubidium
Cesium and rubidium are similar in occurrence, properties, and uses.
Both are soft, silver-white metals, liquid at near room temperature,
and react with oxygen and water. Because of their sensitivity to
light, cesium and rubidium have been employed in photography, tele-
vision, photomultiplier tubes, and scintillation counters. Recently,
interest has been shown toward the use of cesium in ionic propulsion
and thermionic power conversion.
Pollucite (hydrous cesium aluminum silicate) , which occurs only as
a rare constituent of pegmatites, is the principal source of cesium and
rubidium; it contains as much as 36 percent cesium oxide and about
three percent rubidium oxide. Cesium and rubidium also are found in
the pegmatite minerals lepidolite (lithia mica), beryl (beryllium
aluminum silicate) and rhodizite (complex borate of beryllium, alumi-
num, and alkalies), as well as in carnallite (hydrous potassium mag-
nesium chloride) which normally occurs in some saline deposits.
Pollucite has been reported in the pegmatites of San Diego County,
but these occurrences have not been of commercial importance.
Cesium and rubidium were discovered by spectroscopic means about
1860 by Bunsen and Kirchkotf .
Production data on cesium and rubidium and their compounds are
not available for publication.
Gallium
The uses of gallium are limited mainly because of its scarcity, high
cost of extraction and purification, and its corrosive nature. The wide
temperature range through which gallium remains a liquid makes it
of use in high-temperature thermometers and in special use alloys.
Gallium arsenide is being studied for application in high-frequency
transistors, in tunnel diodes, and especially in the field of lasers.
Gallium is as plentiful as lead in the earth's crust, but is much more
Avidely dispersed. Gallium is a gray metal which is liquid at or near
room temperatures. Because of its chemical similarity to aluminum,
gallium is concentrated in clay-rich soils and clay minerals, particu-
larly in those derived from bauxite. It is also concentrated by some
plants, and, therefore, exists in certain coal deposits. Gallium was
discovered by Lech and Bojsbaudian by spectroscopic means in 1875.
Gallium is obtained commercially by the treatment of residues from
aluminum and zinc smelting and refining. The gallium content of
zinc ores from California is not known to the writer, nor has the
gallium content of California coals and clays been investigated. In
recent years, the demand for gallium has been very small, and pro-
duction has not been reported.
Germanium
Germanium, a metalloid, is of value principally because it is a
semi-conductor. This property has led to its use in the electronic
industry, first as diode crystal rectifiers, and later in germanium tri-
odes or transistors.
Germanium occurs as a minor constituent in the sulfides of zinc, cop-
per, and silver, and in trace amounts in coal deposits. Virtually all
of the germanium produced in the United States is recovered during
260 MINERAL AND WATER RESOURCES OF CALIFORNIA
the treatment of zinc ores from the Tri-State district. The ger-
manium is extracted from dust collected in electrostatic precipitators
at the zinc smelter.
Germanium was first identified and named by C, Winkler about
1886. The use and production of germanium increased rapidly with
the invention of the transistor. The estimated United States produc-
tion of germanium in 1964 is 20,000 pounds. The XTnited States pro-
duction of germanium has dropped steadily in the past few years,
because increased manufacturing efficiency and smaller devices have
resulted in lower demand for the material. Germanium has not been
recovered from California zinc ores.
Indium
Indium is a soft gray metal resembling tin. It is softer than lead,
is extremely plastic, and is stable in air. Deformation can be re-
peated almost indefinitely without causing the metal to become work
hardened. Indium has a viscosity that changes very slightly over a
wide temperature range. The metal has important lubricating prop-
erties and alloys readily with other metals.
Because of its mechanical and chemical properties, indium has a
wide variety of uses and a great potential for new uses. One of the
principal uses of indium is in sleeve-type bearings to promote resist-
ance to corrosion and wear. It is also used in electronic devices in a
variety of ways.
Indium is not an essential constituent of any of the known minerals
but is widely dispersed in the earth's crust. It is found in propor-
tions of as much as one percent in iron-rich sphalerite, in tin ores, and
in tmigsten ores. It also occurs in pegmatites and has been reported
in alunite, manganotantalite, phlogopite, pyrrhotite, rhodonite,
samarskite, and siderite.
Indium w'as discovered by F. Reich and T. Richter by spectroscopic
means in 1863.
Most of the domestic production of indium is obtained from the
chemical treatment of flue dust and other residues from lead and zinc
smelters. The American Smelting and Refining Co. at Perth Amboy,
New Jersey, is the only domestic producer of indium.
Rhenium
Rhenium is a dense silver white metal with a high-melting point
(3,440° C) . Rhenium has limited use in industry, principally because
of its scarcity and high cost. The principal use of rhenium is in high-
temperature alloys of tungsten and molybdenum. These rhenium al-
loys liave exceptionally good high-temperature strength properties
and sufficient ductility to be work-formed at room temperature. Other
uses are in electronic devices, electrical contacts, thermocouples, and
catialysts.
Although no minerals are known to contain rhenium as an essential
element, it is widely dispersed in the earth's crust. It is concentrated
in molybdenite in proportions of as much as 0.30 percent and in a num-
ber of rare-earth minerals in proportions up to 0.001 percent. Rhen-
ium is commercially extracted from flue dust residue collected in the
roasting of byproduct molybdenite concentrates from copper ore mined
in Arizona.
MINERAL AND WATER RESOURCES OF CALIFORNIA 261
Rhenium was first discovered in 1925 by W. Noddack and I. Tache
by chemically treating columbite.
Production data for rheniimi are not available. There is no pub-
lished data on the rhenium content of California molybdenite.
Selenium
Selenimn is a gray crystalline solid with a semimetallic luster. It
is a semi-metal found with, and related to sulfur and tellurium.
Selenium has a wide variety of uses which would be more numerous
if sufficient supplies were available. Probably the most important use
of selenium is in the electronic .industry where, owing to its semicon-
ductivity, it is of ^reat value as a rectifying medium. Other uses are
in the manufacturing of glass, rubber, steel, and industrial chemicals.
Selenimn was first used in the glass and ceramic industry as a de-
colorizer. The consumption of selenium has increased rapidly since
the invention of semiconductor, devices.
Selenium is found in native sulfur and occurs in the forms of selen-
ides of lead, mercury, silver, copper, and zinc. Selenium is present
in many base metial ores in small proportions.
In 1817, J. J. Berzelius obtained a red to brown precipitate from a
sulfuric acid plant. From this precipitate he obtained a new element
which he called selenium.
The United States produced about 900 thousand pounds of selenium
in 1964. This amount is about one-third of the world production of
selenium.
Some selenium was recovered until 1961, by Anaconda Co. from
the processing of sulfur mined at the Leviathan sulfur mine in Alpine
County. No other data are available on selenium recovered from Cali-
fornia ores.
Thallium
Thallium is a soft bluish-white metal that alloys readily with most
other metals but not with copper, aluminum, manganese, nickel, zinc,
or selenium. The principal use for thallium is in insect and rodent
poisons. Thallium has a significant use in electronics, low-melting
alloys, and in glass.
Thallium occurs in minute quantities in the sulfides of the coimtnon
metals. Three thallium minerals are known : crookesite (copper thal-
lium silver selenide), lorandite (thallium arsenic sulfide), and hutch-
insonite (complex thallium-bearing arsenide) ; but they have not been
found in commercial quantities.
Thallium was discovered in 1861 by W. Cookes by spectroscopic
means.
Commercial thallium is produced in the United States from flue
dusts and other residues that are recovered as byproducts of the roast-
ing of lead and zinc ores. There are no production figures available.
Selected References
Goodwin, J. Grant, 1957, Minor metals, iti Mineral commodities of California:
California Div. Mines Bull. 176, p. 363-366.
Sargent, J. C, 1956, Mineral facts and problems : U.S. Bur. Mines Bull. 556, 1,042
p. (cesium, p. 169-172; gallium, p. 291-2M ; germanium, p. 309-313; indium, p.
359-364; rhenium, p. 745-749; rubidium, p. 751-754; selenium, p. 777-782;
thallium, p. 871-875).
U.S. Bureau of Mines, 1965, Commodity data summaries, cesium and rubidium,
germanium, rhenium, and selenium : p. 28-29, 58-59, 124-125, 132-133.
262 MINERAL AND WATER RESOURCES OF CALIFORNIA
MOLYBDENUM
(By R. U. King, U.S. Geological Survey, Denver, Colo.)
Molybdenum is a vitally important metal in our modern ferrous
metals industry. About 85 percent of the molybdenum produced do-
mestically is used as an alloying element in the manufacture of high-
temperature alloy steels, stainless steel, castings, and special steel
products. When alloyed witli iron and steel it improves the properties
of hardness, toughness, and resistance to corrosion. Molybdenum
also is used in the manufacture of chemicals, pigments, catalysts,
lubricants, and agricultural products. New uses currently being de-
veloped in the nuclear power field and in the missile and aerospace
industries promise a continued increase in demand for this versatile
metal.
Molybdenum is widely but sparsely distributed in the rocks of the
earth's crust. It is found in trace amounts in most igneous and
sedimentary rocks, in ocean water, in soils, and in plant and animal
tissues. The average content of the earth's crust has been estimated
to be about 0.00025 percent (2.5 parts per million). It is not found
in its pure or native state but only in combination Avith other non-
metallic elements such as sulfur and oxygen, and metallic elements
such as iron, calcium, tungsten, and lead. About a dozen minerals
are known to contain molybdenum as an essential element, but of these,
only two: molybdenite (molybdenum disulfide, M0S2) and wulfenite
(lead molybdate, PbMoOi) have been the source of most of the molyb-
denum produced to date. Other molybdenum minerals which are of
more than i>assing interest, either for their molybdenum content or
their geologic significance, as the demand for this metal continues to
rise include ferrimolybdite (yellow hydrous ferric molybdate) ; powel-
lite (calciimi molybdate), which commonly occui'S with tungsten,
jordisite (black, pow^dery molybdenum sulfide) . and ilsemannite (blue,
water soluble molybdenum oxysulfate). Several rarer minerals of
doubtful significance contain molybdenum combined with one or more
of the following elements: bismuth, copper, magnesimn, vanadium,
cobalt, and uranium.
Deposits or concentrations of molybdenum minerals of economic
significance are foimd chiefly in igneous rocks of granitic composition
and in rocks of sedimentary origin closely related to granitic rocks,
but also are known to occur in sandstone and lignite. In some deposits
molybdenite is spai^sely distributed through rather large masses of
fractured and altered rock ; these are known as disseminated deposits.
Molybdenite may be the sole or chief economic mineral, such as at
Climax, Colorado, and Questa, New Mexico, or it may be a minor
metal associated with copper sulfides as in the large "porphyry" copper
de^^osits of the southwest. Most of the world's production of molyb-
denum comes from the disseminated type of dej^osit. Probably the
most common type of molybdenum cle|X)sits are quartz veins, in which
molybdenite is associated with minerals containing copper, tungsten,
bismuth, lead, and zinc. Pegmatite bodies are a common host for
unusually coarse crystals of molybdenite. Much of the early pro-
duction of molybdenite came from vein and pegmatite deposits.
Deposits of molybdenite often associated with scheelite, powellite,
bismuthinite, or copper sulfides occur in zones of silicated limestone.
MINERAL AND WATER RESOURCES OF CALIFORNIA 263
or in tactile bodies near contacts with intrusive granitic rocks ; they
are known as contact metamorphic deposits and are the source of
molybdenum in California.
In the United States today, the grade of the ore in large deposits (at
least several million tons) mined primarily for the molybdenum con-
tent, ranges from 0.2 to 0.5 percent M0S2, but molybdenum also may be
profitably extracted as a byproduct or coproduct from certain copner,
tmigsten, and uranimn oi'© bodies in which tha molybdenmn content
is not greater than a few hundredths of one percent. Vein deposits,
pegmatites, and many contact metamorphic deposits because of their
limited size have meager economic j)otential except in those deposits
where molybdenite content is at least several percent.
Molybdenum is marketed either in the form of molybdenite con-
centrates (at $1.55 per pound of contained molybdenum, 95 percent
M0S2) or as roasted concentrate (molybdenum trioxide). Concen-
trates, however, are not readily marketable in small or individual lots,
a limiting factor to the economic potential of small deposits.
Although the element molybdenum was identified in the latter part
of the 18th century, its use for many years was restricted largely to
chemicals and dyes. It was not until the early part of the present
century that its potential value was recognized and wide applications
for its use Avere developed. Intensive search for domestic sources of
the metal followed, resulting in the discovery of vein deposits of wul-
fenite and molybdenite in Arizona, and New Mexico, and of the large
disseminated molybdenum and copper-molybdenum porphyry deposits
of the southwestern states. -
Commercial production of molybdenum began in the United States
just before the turn of the century, and was small and intermittent
until 1914. Since 1914, domestic production of molybdenum has in-
creased each year with few exceptions, exceeding 500 short tons for
the first time in 1925, and growing to a current annual rate of over
33,000 short tons. The United States ranks first in world production
of this valuable metal, accounting for about 70 percent of the total.
About one-third of our domestic production is exported to some 30
nations around the world.
Mining of molybdenum in California is reported as early as the
year 1894, from a disseminated molybdenite deposit near Ramona, San
Diego County. Small quantities of molybdenum concentrates were
produced from several properties between 1914 and 1918, and a small
production is reported from a vein deposit between 1932 and 1935.
From about 1937 through 1953 more than 6 million pounds of molyb-
denum were produced from contact metamorphic tungsten deposits
at the Pine Creek mine, Inyo County (Bateman, 1956, p. 23). Over
the years California has ranked from 4th to 6th in U.S. production of
molybdenum due solely to the consistent yield from the Pine Creek
mine.
Occurrences in California
California's molybdenum deposits are widespread, being reported
from more than 80 localities in 24 counties. Of these, ten have yielded
significant quantities of molybdenum, and one, the Pine Creek mine,
is being successfully exploited today. Forty-four deposits or groups
of deposits are briefly described in table 28, and their locations are
shown on figure 40.
264
MINERAL AND WATER RESOURCES OF CALIFORNIA
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Figure 40. Moly.bdenum in California ( numbers refer to table 28) .
Most of the known molybdenum deposits of California are in the
Sierra Nevada province. They include the very productive deposits
of the Pine Creek mine (no. 19, figure 40), which contain the largest
molybdenum reserves in the State. According to Bateman (1956)
the ore bodies are in a pendant of metamorphic rocks enclosed in gran-
ite and quartz monzonite of the Sierra Nevada batholith. Both molyb-
denum and tungsten occur in distinct shoots along the contact of a
belt of marble on the west side of the pendant and quartz monzonite.
The molybdenum ore shoots are subordinate to the tungsten shoots
and are mostly confined to the upper parts of the deposit. Ore miner-
als are scheelite and molybdenite with substantial amounts of copper.
Some of the molybdenum shoots contained an average of about 1 per-
cent M0S2. Although data are not available on which to calculate
reserves, they can be fairly estimated to be large and adequate for
268 MINERAL AND WATER RESOURCES OF CALIFORNIA ■
continued production of molybdenum as a co-product with tungsten
for many years. A number of other contact metamorphic deposits are
known in which molybdenite is associated with scheelite, powellite,
and copper sulfides, in skarn, tactite, or marble, but they are too small
and their molybdenum content is too low to be of economic significance.
Vein deposits of molybdenum also occur over the length of the
Sierra Nevada province, but only two, the Mohawk (No. 4) and the
Blue Speck (No. 15) have yielded any molybdenum of consequence.
In these deposits, molybdenite occurs alone or with pyrite and chal-
copyrite in quartz veins.
Molybdenite is weakly disseminated in granodiorite at the Kaweah
molybdenum property (No. 22) and at the Golden group (No. 28) in
the southern part of the Sierra Nevada province. Although ore-grade
material has been reported in these deposits, the average molybdenum
content is too low for economic exploitation under present conditions.
The southern Cascades and Klamath Mountains provinces contain
only a few molybdenum deposits. Small shipments of sorted ore have
been made from high-grade ore zones at the Boulder Creek mine (No.
2) . The molybdenite is disseminated in an aplite dike, and is reported
to average about 1 percent.
Molybdenite occurs in a few vein deposits and in a disseminated
deposit in the granitic rocks in the western part of the Great Basin
province, and wulfenite is present in the upper parts of lead-zinc veins
in porphyritic and metamorphic rocks in the Mojave Desert province.
A little molybdenimi has been produced from the quartz-molybdenite
vein deposits at the Lucky Boy Prospect (No. 29) and from the wul-
f enite-bearing deposits at the Imperial Property ( No. 32 ) .
Molybdenum deposits in the Coast Ranges and Transverse Ranges
provinces consist of quartz veins in granitic rocks that contain small
amounts of molybdenite. They have not been productive of molybde-
num.
Small amounts of molybdenum have been produced from two dis-
seminated deposits in the western part of the Peninsular Ranges
province in the veiy southern part of the State. The deposits are in
a belt of aplitic rocks that trends northwestward from the Mexican
border and include the Campo (No. 43) and Bour (No. 40) mines.
The molybdenum content of these deposits is too low to be economically
mined under present conditions.
Potential sources of molybdenum in California are most likely to
be found in disseminated deposits in aplitic rocks in the Peninsular
Ranges and in the southern part of the Sierra Nevada, but the pos-
sibility of finding high-grade bodies in some of the contact meta-
morphic deposits in the central and northern parts of the Sierra
Nevada should not be overlooked.
Selected References
Averill, C. V., 1939, Mineral resources of Shasta County : California Jour. Mines
and Geology, v. 35, no. 2, p. 108-191.
Bateman. P. C, 1956, Economic geology of the Bishop tungsten district, Cali-
fornia : California Div. Mines Spec. Kept. 47, 87 p.
Calkins, F. C, 1917, Molybdenite near Ramona, San Diego County, California :
U.S. Geol. Survey Bull. 640-D. p. 73-76.
MINERAL AND WATER RESOURCES OF CALIFORNIA 269
Hess, F. L., 1908, Some molybdenite deposits of Maine, Utah, and California:
U.S. Geol. Survey Bull. 340-D, p. 231-240.
Horton, F. W., 1916, Molybdenum : Its ores and their concentration : U.S. Bur.
Mines Bull. Ill, 128 p.
Kirkemo, Harold, Anderson, C. A., and Creasey, S. C, 1965, Examinations of
molybdenum deposits in the conterminous United States, 1942-1960 : U.S.
Geol. Survey Bull. 1,182-E, 90 p.
Krauskopf, K. B., 1953, Tvmgsten deposits of Madera, Fresno, and iTulare Coun-
ties, California : California Div. Mines Spec. Rept. 35, 83 p.
MacKevett, E. M., Jr., 1960, Geology and ore deposit's of the Kern River uranium
area, California : U.S. Geol. Survey Bull. 1,087-F, p. 169-219.
Pabst, A., 1954, Brannerite from California : Am. Mineralogist, v. 39, nos. 1-2,
p. 109-117.
Robertson, J. F., and Tatlock, D. B., 1965, Consumnes Copper mine, in Kirkemo,
H., and others : Examinations of molybdenum deposits in the conterminous
United States, 1942-1960: U.S. Geol. Survey Bull. 1,182-E, p. 35-36.
Sampson, R. J., 1937, Mineral resource of Los Angeles County : California .Jour.
Mines and Geology, v. 33, no. 3, p. 173-260.
Stager, H. K., 1965a, White Horse and Bay Horse claims, in Kirkemo, Harold.
and others, examinations of molybdenum deposits in the conterminous United
States, 1942-1960 : U.S. Geol. Survey Bull. 1,182-E, p. 33-35.
Stager, H. K., 1965b, September group claims, in Kirkemo, Harold, and others.
Examination of molybdenum deposits in the conterminous United States, 1942-
1960 : U.S. Geol. Survey Bull. 1,182-E, p. 40-41.
Tucker, W. B., and Reed, C. H., 1939, Mineral resources of San Diego Counlty :
California Jour. Mines and Geology, v. 35, no. 1, p. 8-55.
, 1939, Mineral resources of San Diego County : California Jour. Mines and
Geology, v. 34, no. 4, p. 368-500.
Turner, H. W., 1898, Notes on rocks and minerals from California : Am. Jour.
Sci., V. 5, p. 421^28.
Walker, G. W., Lovering, T. G., and Stephens, H. G., 1956, Radioactive deposits
in California : California Dept. Nat. Res. Div. Mines Spec. Rept. 49, 38 p.
Weber, F. H., Jr., 1963, Geology and mineral resources of San Diego County,
California : California Div. Mines and Geology, County Rept. 3, 309 p.
NATURAL GAS LIQUIDS
(By C. D. Edgerton, Jr., U.S. Bureau of Mines, Pittsburgh, Pa.)
Natural gas liquids are those hydrocarbon mixtures contained in
natural gas in a subsurface reservoir, and which are recoverable as
liquids by condensation, adsorption, absorption, compression, or re-
frigeration. They include natural gasoline, condensate, or distillate
(cycle products) and liquefied petroleum gases, commonly called LP-
gases or more simply LPG.
The types of natural gas liquids differ from each other in chemical
composition and physical properties. Natural gasoline and conden-
sate contain principally N-pentane and heavier hydrocarbons of the
paraffin series. The boiling point of N-pentane under normal atmos-
pheric pressure is 96.9° F. LP-gases include propane, N-butane, and
iso-butane, with boiling points of minus 43.7° F, plus 31.1° F, and
plus 10.9° F, respectively. Thus, LP-gases, which are nearly always
in the gaseous state, vaporize in any ambient air temperature greater
than 31.1° F.
Natural gas liquids are found in association with natural gas al-
though not all natural gas contains enough liquids to permit their
economical extraction. Therefore, the geographic distribution of nat-
270
MINERAL AND WATER RESOURCES OF CALIFORNIA
ural gas liquids is less than that of natural gas. Natural gas in as-
sociation with crude petroleum in a subsurface reservoir, and con-
taining economic quantities of natural gas liquids, is termed oilwell
gas, wet gas, or casinghead gas. Natural gas from reservoirs in which
there is little or no accumulation of crude petroleum, and which thus
contains no appreciable quantities of natural gas liquids, is called dry
gas.
In California, natural gas liquids production comes entirely from
eight contiguous counties situated in the southern part of the San
Joaquin Valley, the southern coastal area, and the Los Angeles basin
(fig. 41). The five largest counties, by rank, of natural gas liquids
production, are Kern, Los Angeles, Ventura, Santa Barbara, and
Orange. Fresno, Kings, and San Luis Obispo Counties produce
relatively small quantities of natural gas liquids.
FiGUEE 41. Area producing natural gas liquids (lined pattern).
MINERAL AND WATER RESOURCES OF CALIFORNIA
271
Table 29. — Production of natural gas liquids in California, 1911-64
[Thousand gallons per year]
1911 210
1912 1,050
1913 3,486
1914 7, 770
1915 12, 852
1916 17,178
1917 28, 812
1918 32,256
1919 40,404
1920 48,216
1921 58, 212
1922 67,116
1923 173, 334
1924 232,554
1925 303, 198
1926 389,382
1927 498, 036
1928 584,094
1929 840, 336
1930 829, 710
19Cn 680,358
1932 551,376
1933 499,968
1934 507.612
1935 544, 404
1936 611, 898
1937 641,508
1938 690, 396
1939— _: 640, 542
1940 635, 124
1941 659, 778
1942 633,318
1943 693,336
1944 771,288
1945 891, 744
1946 910, 518
1947-
1948_
1949-
1950-
1951-
1952-
1953-
1954-
1955-
1956-
1957-
1958-
1959-
1960.
1961-
1962-
1963.
1964.
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
064, 112
115, 058
140, 468
189, 776
240, 386
266, 048
307, 922
319, 346
290, 551
287, 134
234, 121
196, 037
230, 589
203,035
187, 645
124,282
108, 806
072, 987
Source : U.S. Bureau of Mines.
Table 29 gives the total annual production of natural gas liquids in
California from 1911 through 1964; figure 42 presents these data
graphically.
The peak year for natural gas liquids production was 1954, when
more than 1.3 billion gallons was produced. From 1955-1964 pro-
duction trended downward and in 1964 was 1.06 billion gallons, about
81 percent of the 1954 figure.
t1 .400.000
1911 15 20 25 30 35 40 45 50 55 60 65
Figure 42. Production of natural gas liquids in California, 1911-64.
272
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA 273
Table 30 gives the total yearly production of natural gas liquids in
California, by counties, from 1954 through 1964. Data for the five
major producing counties are shown on figure 43. Since 1954, only
Santa Barbara County has shown steady growth in natural gas liquids
production largely from development of offshore oilfields.
400.000
350.000 -
Kern
300,000
250,000
Los Ange les
200,000
Ve n t u r a
150.000
100.000
Orange
Santa Barbara
50.000
0 [
1960
'961 1962 1963 1984
Figure 43. Production of natural gas liquids in California, by counties, 1960-M.
274 MINERAL AND WATER RESOURCES OF CALIFORNIA
As of January 1, 1964, there were 66 natural gasoline and cycle
plants in California with a total capacity of 4,688,000 gallons of natural
gas liquids per day. The average operating plant capacity was 71,000
gallons per day. By comparison, there were 623 plants in the United
States with a total capacity of 66 million gallons per day and an
average operating plant capacity of 106,000 gallons per day.
In California, 20 companies operate natural gas liquids plants.
(This figure does not include the U.S. Naval Reserve mothball plant
at Elk Hills.)
Companies with natural gas liquids production capacities greater
than 250,000 gallons per day are :
Gallons
per (lay
Standard Oil Co. of California 677, 000
Shell Oil Co 622,000
Palomaeo 590, 000
Union Oil Co. of California 449, 000
Richfield Oil Corp 434,000
Tidewater Oil Co 347,000
Socony Mobil Oil Co., Inc 307, 000
Texaco, Inc 251, 000
Table 31 gives the companies that operate natural gas liquids plants,
and plant capacities and locations.
Production
Natural gas liquids are extracted from natural gas at plants that
are almost always located in the fields which produce the gas. The
liquids are shipped from the field to refineries or dealers, by pipeline
or truck, and the processed gas, devoid of most of its liquids content,
is either reinjected into subsurface reservoirs to maintain reservoir
pressure, or for secondary recovery operations, utilized for fuel in the
field, or transported by pipeline to markets. In some areas of the
United States, 60 percent or more oilwell gas is vented to the at-
mosphere. In California, less than 1 percent of oilwell gas is vented.
Thus, the conservation of this natural resource in California ap-
proaches the maximum.
There are four basic plant designs for the extraction of liquids from
natural gas: (1) absorption, (2) adsorption, (3) compression, and
(4) refrigeration.
The absorption process is by far the most commonly utilized in both
California and the United States. Plants representing about 90 per-
cent of the total gas processing capacity make use of the absorption
method, either by itself or in combination with refrigeration or com-
pression methods. The .absorption process utilizes a solvent oil which
flows in an absorbing tower countercurrent to the wet natural gas
stream coming from the field. In so doing, the solvent oil strips the
natural gas of its liquids.
The rich solvent oil then goes into a distillation unit where the
natural gas liquids are vaporized, leaving the solvent oil lean again
for recycling to the absorbing tower. The gases then are condensed
and usuall}^ refined further in a rectifying system before leaving the
plant for the refinery.
MINERAL AND WATER RESOURCES OF CALIFORNIA
275
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MINERAL AND WATER RESOURCES OF CALIFORNIA 277
The adsorption process utilizes a solid adsorbing .agent instead of
a solvent oil in a minimmn of two towers. In one tower the wet
natural gas is introduced, where the entrained liquids are adsorbed
(taken up on the surface) by the adsorbing agent. "VVlien the latter
has accumulated .all the liquids it can hold, the wet natural gas stream
is diverted to the other tower. The natural gas liquids on the surface
of the adsorption agent in the first tower are then driven off by the
application of heat, and are condensed and recovered. The adsorp-
tion agent is thus regenerated for the next cycle. By usmg .a mini-
mum of two towers, a continuous operation is effected. Adsorption
plants account for about 10 percent of United States and less than
2 percent of California processing capacity.
A compression plant separates the natural gas liquids by com-
pressing the incoming wet gas and then allowing it to expand. In
so doing, the entrained liquids are cooled below their dew points, and
thus separate out and are recovered. Often several cycles of com-
pression followed by expansion are necessary to effect the practical
ultimate in liquids separation.
A refrigeration plant, like a compression plant, operates on the
principle of cooling the natural gas liquids below their dew points so
they will condense and separate from the natural gas. However, in
this plant design, the liquids are cooled by circulating refrigerants
rather than expansion following compression.
A number of j)lants employ a combination of two or more of the
above ])rocesses such as absorption-refrigeration, refrigeration-com-
pression, and absorption-compression. Natural gas liquids extraction
plants are individually designed using such parameters as total
liquids content of the natural gas to be processed, composition of the
liquids component, reservoir pressure, and local economics.
By far the largest nmnber of plants in California, as in the United
States, utilize the absorption design, followed by combination refrig-
eration, compression, and adsorption designs.
Utilization
Most of the natural gas liquids produced in California, and espe-
cially the natural gasolines, are shipped to petroleum refineries (com-
monly by pipeline, but occasionally by tank truck) where they usually
are catalytically reformed and blended to produce high-octane gaso-
lines. LP-gases are sold, either by companies specializing in their
sale and distribution, or by refineries, for residential, commercial, and
industral fuel, as fuel for internal combustion engines, or as petro-
chemical plant feedstocks where they are used in the manufacture of a
multiplicity of chemicals including synthetic rubber. Some LP-gases
are used in the secondary recovery of crude petrol emn by injecting
them as a "slug" prior to injecting water or natural gas. Small quan-
tities of natural gas liquids are used as solvents and in portable heating
and lighting equipment such as camp stoves and lanterns, blow torches,
and weed-burning units.
278
MINERAL AND WATER RESOURCES OF CALIFORNIA
Consumption of natural gas liquids in California during 1963
for various purposes is given below :
Thousand
Use : gallons
Residential and commercial fuel 233, 962
Chemical plant feedstock ' 116, 902
Petroleum refinery fuel M9, 476
Exports 36,582
Industrial fuel 36, 090
Internal combustion engine fuel 33, 799
Synthetic rubber manufacture ^24,066
Secondary recovery of petroleum ^ 9, 072
Utility gas 26, 4M
Miscellaneous 3, 245
Total 569,688
1 Estimated.
Source : U.S. Bureau of Mines.
Value and Prices
The relative value of natural gas liquids compared with the total
value of all mineral commodities produced in California has shown an
overall decline since 1954. In 1951, natural gas liquids accounted
for nearly 8 percent of the total mineral revenue, but by 1961 this
figure had dropped to less than 5 percent. The total value of natural
gas liquids also declined during this period from $111.6 million to $70
million.
These declines reflected not only the decreasing output of natural gas
liquids, but also an overall erosion of prices throughout the 10-year
period. The average price of natural gasoline and cycle products
dropped from 9.7 cents per gallon in 1954 to 7.5 cents per gallon in
1964; that of LP-gases went from 5.6 cents to 4.5 cents per gallon.
The values of California mineral production and natural gas liquids,
from 1954 through 1964, are shown in table 32.
Table 32. — Comparative values of California's total mineral production and
natural gas liquids, 195Jf-6J!f
Year
Total value of all
mineral production
Total value of all
natural gas liquids
Percent of total
mineral value
represented by
natural gas liquids
1954
Thousand dollars
1, 430, 000
1, 458, 000
1, 555, 000
1, 651, 000
1,501,000
1, 424, 000
1, 402, 000
1,421,000
1,467,000
1,525,000
1, 561, 000
Thousand dollars
111, 555
108, 382
105, 947
101, 776
87, 163
89,283
83,978
79,450
73, 754
71, 517
69,981
7.8
1955
7.4
1956.- .
6.8
1957
6.2
1958
5.8
1959
6.3
1%0
6.0
1961
5.6
1962
5.0
1963
4.7
1964 . -- .
4.5
The price per gallon and total value of natural gas liquids, by type,
from 1954 to 1964, are shown in table 33.
MINERAL AND WATER RESOURCES OF CALIFORNIA 279
Table 33. — Price per gallon and total value of natural gas liquids, iy type, 1954-64
Natural gasoline and cycle products
LP-gases
Year
Price per gallon
(cents)
Total value
(thousand dollars)
Price per gallon
(cents)
Total value
(thousand dollars)
1954
9.7
9.6
9.6
9.6
8.0
8.2
7.9
7.6
7.6
7.6
7.5
•
89, 293
89, 003
84, 615
81,355
68, 485
68. 023
62, 496
57, 645
54, 460
54, 188
54,088
5.6
5.4
5.2
5.2
5.4
5.4
5.3
5.1
4.7
4.4
4.5
22, 262
19, 379
21 332
1955. - .
1956
1957
20, 421
18, 678
21 260
1958
1959
1960
21 482
1961
21 805
1962
19, 294
17, 329
15, 893
1963
1964
Reserves
Table 34 gives reserves for California and the rest of United States
as estimated by the American Gas Association Committee on Natural
Gas Reserves.
Table 34. — Estimated proi'cd rccovcraMc reserves of natural gas liquids in
California and in the United. States, Dec. 31, 1964 ^
[Thousands of 42-gallon barrels]
Locale
Nonassoci-
ated with oil
Associated
wth oil
Dissolved
in oil
Total
California, including offshore
United States, exf^luding California
9,745
4, 782, 088
80, 513
984, 535
182, 706
1. 707, 015
272.964
7, 473, 668
Total _ .
4, 791, 833
1, 065. 048
1, 889, 751
7, 746, 632
' Includes condensate, natural gasoline, and liquefied petroleum gas.
Selected References
American Gas Association, American Petroleum Institute, and Canadian Petro-
leum Association, Dec. 31, 1964, Reports on proved reserves of crude oil,
natural gas liquids, and natural gas in the United States and Canada, 33 p.
American Geological Institute, 1957, Glossary of geology and related sciences,
p. 195.
Hart, Earl W.. 1957, Natural gas liquids, in Mineral Commodities of California :
California Div. Mines and Geology Bull. 176, p. 385-390.
Oil and Gas .Journal, Mar. 29, 1964, Gas-processing number, v. 63, no. 13, p. 59-61,
84-85, 98-100, 105, 108-109, 113-118, 120-123, 125-133.
U.S. Bureau of Mines, 1960, Bull. 585, p. 601-602.
, Minerals Yearbook, 1963 ed., v. II, p. 361-388 ; v. Ill, p. 170-171.
, Jan. 1, 1964, Natural gas-processing plants in the United States : Mineral
Industry Survey, 16 p.
, Jan. 1, 1964, Petroleum refineries, natural gasoline plants, and cycle
plants in District Five, 5 p.
-, Aug. 3, 1964, Shipments of liquified petroleum gases and ethane in 1963 :
Mineral Industry Survey, 12 p.
NICKEL
(By P. E. Hotz, U.S. Geological Survey, Menlo Park, Calif.)
Nickel, a hard, silvery white metal, has, besides its use in coinage, a
multitude of industrial uses as an alloy with other metals. The prin-
cipal consumption is in the production of ferrous alloys, but it also
280 MINERAL AND WATER RESOURCES OF CALIFORNIA
is combined with other metals, especially copper and chromium. To a
lesser extent, uncombined metallic nickel is used for electroplating, in
certain kinds of storage batteries, and in powder form it has many
applications in the chemical and electronic industries. With each year,
continuing research finds new uses for nickel, primarily as an alloy.
The United States production of nickel in 1963 was about 4 percent
of the free world production of 271,000 tons, while the consumption by
this country was 125,000 tons or slightly more than 46 percent of the
free world output. Most of the United States imports of nickel are
from Canadian sulfide deposits; some, smelted from Canadian ores,
comes from Norway; and a small amount derived from New Cale-
donia nickel silicate ores is imported from France. The output from
Cuban laterite deposits, formerly developed and mined by United
States companies, now goes to the U.S.S.R. and Czechoslovakia in the
form of concentrates ( Ware, 1964). The entire domestic mine output
of nickel is from a lateritic deposit at Nickel Mountain, near Riddle,
Oregon, owned by the Hanna Mining Co. There is no recorded pro-
duction from California.
The useful deposits of nickel ores are of two main types: (1) sulfide
deposits, and (2) laterites. Both types have representatives in
California.
In the sulfide deposits pentlandite (Fe,Ni)9Ss, and pyrrhotite, an
iron sulfide wdiich is commonly nickel if erous due to inclusions of
pentlandite, are the principal nickel-bearing minerals. Minor quan-
tities of other nickel minerals, including violarite, Ni2FeS4, and siege-
nite (Co,Ni)3S4, and millerite, NiS, may also be present. The sulfide
deposits are associated wdth mafic intrusive igneous rocks such as
gabbro and peridotite, and occur in large disseminated bodies and small
to moderate-size massive sulfide bodies. The mineralization is closely
related to deep-seated magmatic processes which were responsible for
the emplacement of the igneous intrusions into the surrounding county
rocks.
Lateritic deposits can be subdivided into two closely related types :
(1) nickel silicate laterites of low iron content, and (2) ferruginous
nickeliferous laterites. In nickel silicate ores the nickel-bearing min-
erals are green hydrous nickel-magnesium silicates with rather widely
variable nickel content, which are commonly referred to under the
general name garnierite. The ferruginous nickeliferous laterites are
surficial blankets of reddish-brown soil of variable, complex min-
eralogy in which there is no specific, discernible nickel mineral. The
nickel, invariably accompanied by smaller amounts of cobalt, is in-
timately combined in an unidentified way with hydratecl iron com-
pounds, clays, and serpentine minerals in the soil. The nickel silicate
and ferruginous nickeliferous laterites are everyw^here underlain by
bodies of ultramafic rock, commonly peridotite or serpentinite, from
which the nickeliferous deposits have been formed by extensive weath-
ering. Hence this type of deposit is referred to as secondary. Most
peridotite and its altered equivalent, serpentinite, contains between
0.1 and 0.3 percent nickel and about .01 percent cobalt, which occur
as minor chemical constituents in one or more of the magnesium-iron
silicate minerals of the parent rock. Under the influence of natural
weathering processes, the rock-forming minerals are decomposed and
MINERAL AND WATER RESOURCES OF CALIFORNIA
281
the more soluble compounds, principally magnesia and silica, are
carried away by downward percolating rainwater, while the less mobile
constituents, including hydrous iron oxide, nickel, and cobalt are
concentrated in a residual blanket. Under some circumstances some
nickel is dissolved, removed, and redeposited with silica to form a
boxwork of microcrystalline quartz and garnierite below the soil zone,
above a substratum of partially weathered peridotite or serpentinite
(Hotz, 1964).
Sulfide Deposits
A sulfide deposit occurs in the Julian-Cuyamaca area of San Diego
County near the town of Julian, in the eastern part of the Peninsular
Ranges province (fig. 44). The Friday mine (Creasey, 1946), which
was probably discovered in the 188{)'s, has been intennittently ex-
plored and developed by underground workings and diamond drilling.
EXPLANATION
•
Ferruginous nickeli ferous
lateri tes
1. Pine Flat Mtn.
2. Gasquet
3. Rattlesnake Mtn.
4. Little Red Mtn,
5. Dunsmuir
O
Siliceous laterites
6. Pilliken
7. Valley Springs
8. Venice Hills and
Deep Creek
♦
Nickel sulfide
.MON<i\ 4-38- 9. Old Ironsides
\ 10. Friday
-rRoyG.H|5r^
Figure 44. Nickel in California.
©7-164 O— 6i6-^t. I 1&
282 MINERAL AND WATER RESOURCES OF CALIFORNIA
There is no recorded production ; however, the size of the underground
workings indicates tluit several lumdred tons of ore luwe been mined.
The deposit is a partly oxidized sulfide replacement of gabbro adjacent
to a schist inclusion, (^reasey (1946, p. 27) estimated the indicated
reserves to be approximately 5,000 tons averaging approximately 2.5
to 3 percent nickel, from 0.5 to 1.0 percent copper, and as much as 0.15
percent cobalt. Subsequent exjjloration under a DMEA contract con-
firmed these estimates and showed that approximately three-fourths
of the deposit is predominantly oxidized ore. Several other occur-
rences of gossan (masses of oxidized sulfides) containing from 0.01
to 1.45 percent nickel (Creasey, 1946, p. 27-28) are known in the
Julian-Cuyamaca area, which suggest the presence of other nickel
sulfide bodies, but limited exploration has not revealed any important
deposits. Creasey (1946, p. 19-22) reports as much as 3 percent pyr-
rhotite in the gabbro body, suggesting that the rock may contain small
amounts of nickel, but no analyses of the rock for nickel have been
reported.
Exploration under a DMEA contract of a small nickel- and copper-
bearing gossan at the Old Ironsides mine, approximately 9 miles
north-northeast of Ramona, San Diego County (Peninsular province)
revealed a small shallow deposit averaging about 0.35 percent nickel.
Lateritic Deposits
The principal lateritic nickel de|X)sits in California occur in the
northwestern part of the State, chiefly in Del Norte County and in
southern Siskiyou County (Klamath Mountains province) ; deposits
are also known in northern Mendocino County (California Coast
Ranges). Some eroded remnants of de]3osits in the western Sierra
Nevada province have been reported by Rice (1957, p. 396).
The deposits in northwestern California are accumulations of later-
itic soil resting on peridotite. They occupy nearly flat-lying to gently
sloping areas on broad ridge crests, in saddles, and on benches on the
sides of ridges in a thoroughly dissected and deeply eroded rugged
mountainous terrain. The individual deposits are scattered, discon-
tinuous areas that range from less than 100 acres to about 300 acres.
Thickness of the blankets vary widely and are only approximately
known, but range from as little as 10 to 15 feet to as much as 80 to 90
feet. Characteristically, the deposits in northwestern California are
blankets of reddish-brown soil at the surface grading downward 1 to
3 feet below the surface to ocherous soil, which passes more or less
gradationally downward into bedrock. Except for an occasional
veinlet or film of garnierite coating joint surfaces, no nickel minerals
have been recognized. In places isolated, residual blocks or boulders
of leached, barren silica boxworks are scattered on the surface of the
lateritic blankets, and chips of microcrystalline quartz occur in the
soil and occasionally as veinlets near the base of the soil zone.
Several deposits are known in Del Norte County wiiere lateritic soil
has accumulated on a large pluton of peridotite and serpentine. The
best known deposits, which have been explored by drilling by private
companies and the U.S. Bureau of Mines (Benson, 1963), are at Pine
Flat and Diamond Flat on Pine Flat Mountain about 20 miles north-
east of Crescent City, near the California-Oregon boundary. Several
others, some of which have been tested by private companies, are
MINERAL AND WATER RESOURCES OF CALIFORNIA 283
known near Gasquet, a town on Smith Eiver approximately 18 miles
east of Crescent City. Some small patches of lateritic soil are also
known along a long, narrow north-south ridge of ultramafic rock
south of Gasquet, known as Rattlesnake Mountain. A few other
isolated deposits only a few acres in extent are also known in this
general region.
One deposit is known in northern Mendocino County at Little Red
Mountain, approximately 2.5 miles east of Leggett. The deposit
occurs on the southern part of an isolated ultramafic body in the
northern Coast Range province, and has been explored by a private
company.
In southern Siskiyou County a small lateritic deposit occupies the
nose of a ridge in the Saci'amento River Canyon north of the mouth
of Little Castle Creek, approximately 2 miles south of Dunsmuir.
No active exploration of this deposit has been undertaken.
Reconnaissance sampling and data from Bureau of Mines explora-
tion (Benson, 1963) show that the thicknesses of the lateritic blankets
vary widely and are only approximately known, but they are esti-
mated to be less than 50 feet thick and probably, on the average, sel-
dom more than 25 to 330 feet. The average nickel content ranges
from 0.5 to 0.8 percent nickel, 0.01 to 0.1 percent cobalt, and the iron
content is less than 20 percent.
Several lateritic remnants on serpentinite are known in the western
Sierra Nevada province (Rice, 1957, p. 396). They consist mostly of
cappings of dense silica box work grading into jasperlike silicified
serpentinite. Some garnierite fills cavaties in the boxwork and occurs
as veinlets in the serpentinite. The cappings are more than 100 feet
thick in places but the rocks are leached and the average nickel content
is less than 0.5 percent. Siliceous laterite remnants are exposed at
the Pilliken chromite mine in El Dorado County; a few miles east
of Valley Springs in Calaveras County ; and in the Venice Hills and
Deer Creek areas of Tulare County. The only known exploration of
the western Sierra lateritic deposits through 1956 (Rice, 1957, p. 396)
was in a small area in the eastern part of the Venice Hills.
Resource Potential
The resources of nickel are only imperfectly known. Reserves of
nickel-bearing sulfide ores are very meager, probably amounting to
less than a few thousand tons. There may be on the order of 25 million
tons of nickeliferous laterites in nortliAvestern California which aver-
age 0.8 percent nickel or less, distributed among several widely scat-
tered deposits. It seems unlikely that these resources will be com-
mercially exploited in the foreseeable future, because of their low grade
and dispersal among several relatively small deposits. Unlike the
Nickel Mountain deposit in Oregon they do not have bodies of high-
grade nickel silicate with which to increase the average nickel content
of the ore.
Selected References
Benson. W. T., 1963, Pine Flat and Diamond Flat nickel-bearing laterite deposits,
Del Norte County, California : U.S. Bur. Mines Kept. Inv. 6,206, 19 p.
Creasey, S. C, 1946, Geology and nickel mineralization of the Julian-Cuyamaca
area, San Diego County, California : California Jour. Mines and Geology, v.
42, no. 1, p. 15-29.
284 MINERAL AND WATER RESOURCES OF CALIFORNIA
Hotz, P. E., 1964, Nickeliferous laterites in southwestern Oregon and north-
western California : Ecou. Geology, v. 59, no. 3, p. 355-396.
Rice, S. J., 1957, Nickel, iu Mineral commodities of California : California Div.
Mines Bull. 170, p. 391-399.
Ware, G. C, 1964, Nickel : U.S. Bur. Mines, Minerals Yearbook, 1963, p. 843-857.
NIOBIUM AND TANTALUM
(By R. L. I'arker, U.S. Geological Survey, Washington, D.C.)
The rare metals, niobium and tantalum, have become increasingly
important in modern technology and are required in certain electronic,
nuclear, chemical, and high-temperature metallurgical applications.
Both metals are used for A'acuum tube elements, su])er conductors, cor-
rosive-resistant vessels, and laboratory ware, and as constituents in
high-temperature alloys and austenitic stainless steel. Niobium is spe-
cially used for cladding nuclear fuels, Avhereas tantalum is used for
capacitors, rectifiers, and surgical implants and as a catalyst in the
manufacture of butadiene rubber (Miller, 1959; Barton, 1962).
Although the United States is the world's largest consumer of
niobimn and tantalum, it is a small producer and relies on foreign
sources for its ore supply. Critical shortages of these metals resulted
in government allocation controls during World War II and the
Korean War, and a strategic stockpile of niobium-tantalum raw ma-
terials is now mamtained by the Government. During the last 10
years imports of niobium-tantalum concentrates have ranged from
an alltime high of 11,520,262 pounds in 1955 to a low of 3,591,530
pounds in 1958. In 1963, 6,853,971 pounds of niobium-tantalum con-
centrates were imported. Domestic production reached a peak of 428,-
347 pounds of concentrates in 1958, most of which came from Idaho
placers. This production, however, amounted to only about one-tenth
of that year's domestic consumption. No domestic production has
been recorded since 1959 (U.S. Bur. Mines Minerals Yearbooks, 1955-
1963).
Niobium and tantakmi commonly occur together in the same min-
erals. These minerals also commonly contain subordinate amounts
of titanium, iron, manganese, rare earths, uranium, thorium, and other
metals. Important ore minerals are columbite-tantalite. (Fe, Mn)
(Nb, Ta)oOc; pyrochlore, NaCaNboOr.F; microlite, (Na,' Ca).Tao06
(0,OH,F); euxenite, (Y,Ca,Ce,U,Th) (Nb,Ta,Ti)oOG; fergusonite
(Y,Ca,U,Th) (Nb,Ta)04; and samarskite, (Fe,Y,U)2(Nb,Ti,Ta),0r.
Niobium-tantalum minerals are found in granitic rocks and peg-
matites, in alkalic rock complexes and associated carbonatites, and in
placers derived from these rocks. Some granite massifs contain dis-
seminated columbite-tantalite, euxenite, or other niobiiun-tantalum-
bearing minerals as primary rock constituents, and in some places
weathering and fluvial processes have concentrated these minerals into
commercial deposits. Granite pegmatites are well known for their
concentrations of rare minerals, including minerals of niobium and
tantalum, but the erratic distribution and limited tomiage of these
minerals in pegmatites commonly exclude pegmatites as an important
source of supply. Even so, pegmatites are the principal source of the
world's tantalum.
Large low-grade deposits of niobium occur in alkalic rock complexes
and related carbonatites in many parts of the world. Some multi-
MINERAL AND WATER RESOURCES OF CALIFORNIA
285
million ton deposits are known in central Africa, southeastern Canada,
Norway, and Brazil, and at least five alkalic complexes with carbona-
tites have been found in the United States. Niobium is contained in
the mineral pyroclilore, which commonly is disseminated in the
carbonatite. Alany such deposits are under extensive development and
are expected to be the principal source of niobium in future years.
Commercial deposits of niobiiun and tantalum have not been found
in California, although an undisclosed — but presumably very small —
amount of tantalum was produced from San Diego County in 1920
(Weber, 1963, p. 41, 68). Niobium-tantalum minerals have been re-
ported from widely scattered pegmatites in the State (see fig. 45), but
many of the reported occurrences are poorly documented. So far as
known, all of the niobium-tantalum minerals reported are present only
as minor accessoiy constituents in the pegmatites and are not regarded
as potential sources of niobium and tantalum.
EXPLANATION
Niobium and tantalum in pegmat
1 . Pegma t i t e near Milton
Kern River uranium area
3. Piute Mountains near Weldon
4. Fano mine: Pegma t i f e -sec, 16,
T. 7 S., R. 2 E.; An i t a mine
5. Box Spring Moun tain
6. Southern Pacific Silica Quarry
7. Pomona Tile Quarry
8. Pegma t i t e . Cady Moun ta
9. Little Three mine
1 0. R i nc on district
,t. Pa la district
2. Moun tain Lily mine
13. Chihuahua Valley near Oakgrove
14. Southwest slope of Lawson PeaK
\1 5. Me s a Grande
.MONO\ -I- 38*
te
Figure 45. Niobium and tantalum in pegmatites in California.
286 MINERAL AND WATER RESOURCES OF CALIFORNIA
A carbonatite body associated with alkalic rocks at Mountain Pass,
San Bernardino Ck)iinty contains one of the world's largest deposits
of rare-earth minerals, although only traces of niobium have been
fomid in the deposit (see p. 351, Kare-earth chapter, this volume) . The
occurrence of carbonatite and alkalic rocks in this region, however,
opens the possibility of finding similar and perhaps niobium-bearing
rocks through future geologic study.
Selected References
Barton, W. R., 1962, Columbium and tantalum, a materials survey: U.S. Bur,
Mines Inf. Circ. 8,120, 109 p.
Hanley, J. B., 1951, Economic geology of the Rincon pegmatites, San Diego
County, California : California Div. Mines Spec. Rept. 7-B. 24 p.
Hewett, D. P., and Glass. J. J., 195.3, Two uranium-bearing pegmatite bodies in
San Bernardino County, California : Am. Mineralogist, v. 38, p. 1.040-1,050.
Irelan, William, Jr., 1890, Ninth annual report of the State Mineralogist:
California Miu. Bur. Rept. 9, 352 p.
Jahns, R. H., and Wright, L. A., 1951, Gem and lithium-bearing pegmatites of
the Pala district, San Diego County, California : California Div. Mines
Spec. Rept. 7-A, 72 p.
Kunz, G. F., 1905, Gems, jeweler's materials, and ornamental stones of Cali-
fornia : California Div. Mines Bull. 37, 171 p.
MacKevett, E. M., Jr., 1960, Geology and ore deposits of the Kern River
uranium area, California : U.S. Geol. Survey Bull. 1,087-F, p. 169-222.
Miller, G. L., 1959, Tantalum and niobum : New York, Academic Press, Inc.,
767 p.
Murdoch, Joseph, 1951. Notes on California minerals : nuevite-samarskite ; trona,
and hanksite; gaylussite: Am. Mineralogist, v. 36, p. 3.58-361.
Murdoch, Joseph, and Webb, R. W., 1956, Minerals of California : California Div.
Mines Bull. 173, 4.52 p.
1960, Minerals of California, Supplement for 1955-1957 : California Div.
Mines Bull. 173, supp. no. 1, 64 p.
1964, Minerals of California, Supplement for 1958-1961 : California Div.
Mines Bull. 173, supp. no. 2, 28 p.
Rogers, A. F., 1910, Minerals from the i)egmatite veins of Rincon, San Diego
County, California : Colimibia Univ., School of Mines Quart., v. 31, p. 208-
218.
Schaller, W. T., 1911, Bismuth ochers from San Diego County, California: Am.
Chem. Soc. Journ., v. 33, p. 162-166.
1916, Cassiterite in Sail Diego County, California : U.S. Geol. Survey
Bull. 620. p. 351-354.
Schrader, F. C, Stone, R. W. and Sanford, S.. 1917, Useful minerals of the
United States : U.S. Geol. Survey Bull. 624, 412 p.
Weber, F. H., Jr.. 1963, Geology and mineral resources of San Diego County,
California : California Div. Mines and Geology, County Rept. no. 3, 309 p.
OFFSHORE RESOURCES (EXCLUSIVE OF PETROLEUM)
(By J. W. Padan,^ Ocean Resources, Inc., La Jolla, Calif.)
One has only to read the popular press to gain an idea that mammoth
rich accumulations of sea-floor minerals exist to enrich anyone with
imagination enough to tool up for exploitation. In reality, the much-
heralded day of large scale mining of marine minerals must be pre-
ceded by years of detailed geologic exploration.
"Wliat are the facts ? First, sea-floor minerals do exist. Second, in a
few areas of the world, including California, they are being mined.
1 Formerly with U.S. Bureau of Mines, Tiburon, Calif.
MINERAL AND WATER RESOURCES OF CALIFORNIA 287
Third, most of the mineral occurrences have crept into print on the
basis of a solitary sample. Many of the "vast sea floor mineral de-
posits" have been delineated on the basis of only 3 or 4 samples. Al-
though they may fire our imaginations, to a statistician, these data
are almost meaningless.
This era of promotional literature has served a purpose — consider-
able interest has been provoked in industrial, academic, and govern-
mental circles. All eyes are on the next offshore move.
What is the situation with respect to California's offshore minerals?
The immediate industrial interest here, as elsewhere, is focused upon
the near-shore area. Sand and gravel is being mined from several on-
shore beach deposits. As coastal metropolitan areas expand and en-
croach on much-needed deposits of inshore sand and gravel, offshore
sources are certain to be sought both for construction purposes and for
the restoration of storm-eroded beaches. Sea shells are clredged from
San Francisco Bay as a source of lime for the manufacture of cement.
Sand and silt are dredged for fill material in several coastal areas.
Salt, bromine, and magnesium are recovered from sea water in many
areas of the world, including California. As the saline water con-
version program gains momentum, additional elements and compounds
no doubt will be economically recovered as byproducts. Heavy min-
erals, or black sands, will become exploration targets, especially off-
shore from the mouths of rivers that have coursed through mineralized
zones. Monterey, Drake's, and Half Moon Bays all have aroused some
industrial interest for this reason. Ancient drainage patterns may
offer further clues to offshore targets of heavy minerals. The heavy
minerals of present economic interest are tin, gold, and iron ore (these
three all are being mined offshore somewhere in the world), titanium
ores, platinum, gem stones (diamonds are being mined off the African
Coast; specimens of jade have been recovered by skin-divers off Cali-
fornia) , and tungsten ores.
Of all the minerals on the continental shelf, the one that perhaps
will be exploited first is phosphorite, an essential fertilizer material.
The concentrations of phosphorite appear to be widespread ; samples
have been recovered from more than 250 locations, from Baja Cali-
fornia to San Francisco. An attempt to mine one deposit was aban-
doned, reportedly because of the presence of unexploded naval pro-
jectiles on the sea-floor at the site. Considering the economic potential
of this material, if it truly exists in the great tonnages that are indi-
cated, the sampling to date has been rather modest. Samples of barite
nodules and glauconite have been recovered from the shelf, but their
presence in economic concentrations has not been proved, and their
exploitation appears to be far in the future.
California's continental shelf is narrow. In fact, some of the
occurrences of the above-mentioned minerals actually are on the con-
tinental slope. However, the opportunity to "widen" her shelf was
presented to California last year when the Fourth Convention of the
1958 Geneva Conference on The Law of The Sea became international
law. The shelf now is defined as, ". . . the seabed and subsoil of the
submarine areas adjacent to the coast but outside the area of the
territorial sea, to a depth of 200 meters or, beyond that limit, to
where depth of the superjacent waters admits of the exploitation of
288 MINERAL AND WATER RESOURCES OF CALIFORNIA
the natural resources of the said areas . . .". Thus, mining of the
deep water nodules containing manganese, nickel, cobalt, and copper
will legally extend the continental shelves of many coastal nations.
The nodules have been sampled fairly well and appear to be present
in quantity, but the deposit selected for initial exploitation will cer-
tainly have to be sampled in considerably more detail. Once the
extent and market value are determined with reasonable confidence,
then there will be reason to solve the mining technology problems
that may remain. Deep ocean red clays someday may become a
source of alumina, and calcareous and siliceous oozes may find use
as construction materials.
Assessing the marine minerals in perspective, w^e can see that an
expanded marine mineral industry in California depends upon an
evaluation of "what is down there." Only an exploration program
can supply the answers. The California-based federal program
originally was conceived to fill this gap. However, Congress has re-
oriented the program and the next move appears to be up to industry.
Selected References
Department of the Interior and Related Agencies Appropriations Bill, 1965:
U.S. House of Representatives Committee on Appropriations, Rept. No. 1237,
p. 12.
Four Conventions and an Optional Protocol Formulatecl at the United Nations
Conference on the Law of the Sea : Message from the President of the United
States, The White House, Sept. 9, 1959, 80 p.
Mero, J. L., 1965, The Mineral resources of the sea : New York, Elsevier Pub-
lishing Co., 312 p.
PEAT
(By C. W. Jennings, California Division of Mines and Geology, San Francisco,
Calif.)
Utilization
The principal use of peat in the United States is as a soil conditioner.
Peat contains a large percentage of fibrous and porous organic matter
(humus) wliich improves the physical structure of the soil and pro-
motes plant development when used in large enough quantities. Peat
mixed with heavy clay soils makes them more granular, less plastic,
and consequently more permeable to water, air, roots, and micro-orga-
nisms. In sandy soils, peat helps bind the soil particles, retards exces-
sive percolation, and makes the soils more retentive of moisture and
nutrients. Contrary to popular belief, peat is not a fertilizer, and
the nitrogen that it contains is not readily given up as a plant food
like the "soluble nitrogen"' of artificial fertilizer. However, peat does
contain soluble humic acid and is desirable for preparing soil for
plants that prefer an acid condition, sucli as rhododendrons, azaleas,
camellias, and gardenias. Peat commonly is mixed with sand and
loam soil in the preparation of potting mixtures or media for the ger-
mination of se«ds.
The second largest market of peat in this country is as an ingredient
or filler in mixed fertilizers in which it acts as a carrier for the primary
nutrients — nitrogen, phosphoric oxide, and potash — not as an agent
MINERAL AND WATER RESOURCES OF CALIFORNIA 289
for supplying plant food. Well-decomposed peat dried and ground is
ordinarily used for this purpose.
Because of its moisture-absorbing qualities, fibrous peat sometimes
is used as a litter material for bedding livestock, and its deodorizing
capacity makes it useful in stable and poultry yards. Nurserymen,
gardeners, and others use peat as a packing material for plants, fruit,
vegetables, eggs, fish bait, and fragile materials, and as a medium for
growing mushrooms and earthworms. Other uses of peat include fil-
tering agents, dye stuffs, tanning substances, and as ^ibsorbent in surgi-
cal dressings, but the quantities so used are small.
In several European countries, peat is used as a fuel, but is is not so
used in the United States because of ample supplies of superior fuels
with much higher calorific values.
Geologic Occurrence
Peat is an accumulation of partly decomposed and disintegrated
vegetal matter, representing the first stage in the transition of plants to
coal. It forms in undrained depressions, plains, or river deltas that
contain environments favorable to luxuriant growth of peat-forming
plants. The plants range from woody shrubs and trees of swamps, to
mosses, sedges, reeds, and grasses of marshes. Poor drainage is essen-
tial in the formation of peat, because standing water largely excludes
oxygen and prevents complete decay, thus enabling the carbonaceous
matter to be preserved.
The type of vegetation that accumulates determines the type of
peat that is formed. The most valuable commercial peat is formed
from aquatic mosses. Other commercial grades of peat include reed
or sedge peat, and peat humus, which is a soil high in organic matter.
Mosi of the peat deposits in California are classified as reed-sedge peat
or peat hunms. A high-grade peat moss, however, is recovered from
a single bog in Modoc County in northern California.
Production
"World production of peat in 1963 was estimated at 170 million short
tons of which 60 percent was used for agricultural purposes and 40
l^ercent for industrial fuel. The U.S.S.R. is the leading producer
with 95 percent of the world output. The United States production
is relatively small and represents less than 1 percent of the world total.
The demand for agricultural peat in the United States has steadily
increased in recent years, and, in 1963, the production reached nearly
600,000 tons — more than double the production of 10 years ago. In
addition, 261,000 tons of peat were imported, principally from Canada.
Wliereas the domestic production of peat has been increasing from
year to year, the quantity of imported peat has remained relatively
constant. The principal peat producing states in the United States
are Michigan, Indiana, Pennsylvania, California, and Washington;
together these states account for three-fourths of the nation's output.
In 1963, California ranked fourth among the states in the amount of
peat produced and second in the value of sales. The average value
per ton of peat in California was $11.29. The demand for peat in this
290
MINERAL AND WATER RESOURCES OF CALIFORNIA
State has risen phenomenally in the past 10 years. The value of peat
sold in 1963 was $450,000 — more than (5 times the value ])roduced in
1953. All of the peat produced in this State, as far as is known, was
used for soil improvement.
California Occurrences and Reserves
Four widely scattered peat deposits are being worked in Oalifomia
as shown on figure 46. These range from a peat moss operation near
Likely, Modoc County, in the northeastern part of the State, to a reed-
sedge type peat bog in a sag pond along the San Andreas fault near
Banning, in southern California. The largest peat reserves are situ-
42".
41'
Eurrk^
40"
124' 123- 122
-n ) I \\
o
121'
^{ S I S K |(y 0\u/-^ -^ \ > I
■a
EXPLANAT ION
Active peat plant
Pea t bog (gene r a I area)
SH^TAl
CASCADE
t
41 =
- 0-' ■
* ' I TRINITY >
124°
^ ^ ,J~. <f ENN / BU*-E v.- SIERRA
^' ^-V--^) L4*5^^nevada]-..
-r» \ y 1 yolo\-^.A/ei. dorado.' N
„ y ;■ \\ ^Sacrai*nto ■'Or
119°
39*
1. John J. Harris, Peat Moss
L i ke ly , Mod oc Co.
2 . Vita Peat Inc. ,
Bethel Is.. Contra Costa Co.
3. P. J. Ganbetta Delta Dredging,
Brentaood . Cont ra Costa Co.
4. Round Valley Peat bogs
5. Scot t Va I ley pea t bog
6 . la tsonv i I le pea t
7 . Sail nas R i ve r pea t
8. San Anton i o Va I ley Peat
9. Ch i no pea t bog
ID. McCe I Ian & Sons Peat.
Huntington Beach, Orange Co.
It. San Luis Rey peat bog
38--K"'-e..l>Jfe^«^^ '"^^ /
123°Si>
Francisco
y- TUOLUMNE '";^\moNO\ -|- 38
SJ'.c CLARA C \/ ^
37° — \>J
■■^\MERe*f^-
. saJ?^.''
3e°-f
122°
\MONTEREY^'S
■\
'"i \\ ^FRESNd^
x^ENITOl \ "7 .y\
SAN ! *
-0 '■• \
C LUIS "-.X B.k»ni(«W
*' OBISPO
35'-(- (y^AprX- J^;^ ^\y^
(kern
MOJAVE
SAN BERNARDINO
121"
I
100
I
150 MILES
33"+
120°
+ \ +
~\-\ —
DESERT "'■>
y^'
1 Y~34"
SIDE \
J
C
\rr^* ^-^
j.
(IMPEB'A^
"l
119"
118"
SALTON \ '^33°
,Su.Di«» [V_ I
117"
116"
lis"
Figure 46. Peat in California.
MINERAL AND WATER RESOURCES OF CALIFORNIA 291
ated in the Sacramento-San Joaquin Delta area, where peat and peaty
muck deposits cover an estimated 400 square miles. Two operators are
dredging reed-sedge peat from Frank's Tract in this area. A small
tonnage of i)e'at humus is being extracted from a deposit near Hunting-
ton Beach, in Orange Comity.
Peat has been mined from San Diego, Santa Cruz, and San Ber-
nardino Counties, and U.S. Soil Survey maps show peat and peaty
muck occurring in Round Valley, Inyo County; near the mouth of
Salinas River, Monterey County: along San Antonio River and south
of the mouth of Santa Maria River, Santa Barbara County; and in
various sites in Siskiyou and Humboldt Counties (U.S. Department
of Agriculture, 1919-19M).
Reserves of peat in California have been estimated by the U.S.
Geological Survey (U.S. Geol. Survey Circ. 293, 1953, p. 38) to be 72
million short, tons (air-dried basis) . The peat reserves of the United
States have been estimated at approximately 14 billion short tons.
Outlook
The outlook for the California peat industry is favorable and pro-
duction is expected to increase. As the population of the State grows
and more homes are built, more peat will be in demand by homeowners,
landscape gardeners, and nurseries. Peat deposits in California have
not been thoroughly studied for economic development; however, the
location of many small deposits are shown on U.S. Department of Agri-
culture soil maps. Possibly a number of these deposits could be
worked.
Selected References
Averitt, Paul, Berryhill, L. R., and Taylor, D. A., 1953, Coal resources of the
United States : U.S. Geol. Survey Cir. 293, p. 38.
Jennings, C. W., 1957, Peat, in Mineral commodities of California : California
Divri;rines:BuTin76, p: 403^^8. ' '
Sheridan, E. T., 1965, Peat, in Mineral facts and problems : U.S. Bur. Mines Bull.
630.
U.S. Department of Agriculture in cooperation with University of California
Agricultural Experiment Station, Soil Survey Reports. (The following Soil
Survey Reports delineate peat deposits : Bishop area, 1928 ; Salinas area, 1925 ;
Santa Ynez area, 1927 ; Santa Maria area, 1919 ; Shasta Valley area, 1923 ;
Eureka area, 1925; Alturas area, 1931 : jacramento- San .Tongu'i r)pH-a arpa,
1941 ; Santa Cruz area, 1944.)
PETROLEUM AND NATURAL GAS
(By M. B. Smith and F. J. Schambeck, U.S. Geological Survey,
Los Angeles, Calif. )
iNTRODUCTTOlSr
Oil is used primarily to produce energy for power or heat, and for
lubrication. More than 2,300 separate products are made by the pe-
troleum industry, some of the principal products being gasoline ; lubri-
cants ; residual and distillate fuel oils ; jet fuel ; raw materials for the
petrochemical, rubber, and fertilizer industries; and asphalt.
292 MINERAL AND WATER RESOURCES OF CALIFORNIA
Most of the crude oil produced in California is of napthenic base
(often called asphaltic base). The crude oil is transported from the
oil fields by pipe lines, ocean tankers, or tank trucks to the 34 refineries
in the State, most of which are near Los Angeles and San Francisco.
These refineries have a capacity of about 1,350,000 barrels per day.
Natural gas is used primarily for space heating and for fuel, but
some is used as a chemical raw material. Most gas in California
occurs in two ways : (1) as "wet gas" in oil sands or closely associated
with oil in an overlying gas cap, or (2) as "dry gas" in separate
zones in oil fields or in gas fields not associated with oil. Wet gas
commonly contains valuable constituents which are removed at proc-
essing plants to obtain natural-gas liquids before the residue gas is
used. Dry gas usually does not contain enough of these constituents
to make the processing economically profitable, so after removing
impurities and blending w^ith other gas to increase the heading value
if necessary, it is distributed by pipe line and used. Slightly more
than one-third of the gas produced along with oil in California is
reinjected under pressure into the oil reservoirs for the purpose of
restoring or maintaining the reservoir pressure and thereby increas-
ing the recovery of oil. Most of this gas will be produced again at
some later date. At present, less than 1 percent of the gas accompany-
ing oil production is wasted by being allowed to escape into the
air, and even this wastage generally occurs during testing operations.
The production of oil and gas in California is extremely important
to the economy of the State as it provides a local source of supply
for a large part of the energy recfuirements of the large and rapidly
growing industry and population. The production, refining, and
distribution of petroleum utilizes a capital investment of $6.9 billion
in facilities and equipment and furnishes employment to some 106,000
persons. Oil producers pay an estimated $140 million annually as
royalties to owners of interests in the production, and some $30 million
annually for rentals on some 5.5 million acres of nonproductive land
held under oil and gas leases. Taxes paid to state and local govern-
ments (exclusive of those paid by gas utilities) are estimated at $620
million for 1964. There are 69 plants in the growing petrochemical
industry employing 45,000 persons with a $325 million payroll. Oil
accounts for 79 percent of all tonnage through California harbors.
The 1964 output of California's 42,000 producing oil wells and 900
producing gas wells in some 350 fields (figs. 47, 48, 55, 56) was 299 mil-
lion 42-gallon barrels of oil and 675 billion cubic fee (net) of gas with
a value at the wells of about $940 million. Tliis amounted to 60 percent
of the value of the entire mineral production in California for the year.
The production %vas obtained from depths as shallow as 200 feet to as
deep as 13,000 feet. The productive area totals about 425,000 acres, or
less than 14 of 1 percent of the area of the State. The only substantial
shut-in production is about 100,000 barrels per day from one zone in
the Elk Hills field in Naval Petroleum Reserve No. 1. However, the
daily yield from many large flowing wells is controlled and is less than
their potential.
The production of crude oil declined nearly continuously from the
peak of 1 million barrels per day in 1953 to 8i3,000 barrels per day in
1962. Since that year production has increased to 860,000 barrels daily
MINERAL AND WATER RESOURCES OF CALIFORNIA
293
4° 123° 122' 121"
Uh A ^/, A -r}f^^^ O M o dIo ;
Kb.AIVIAT>^ jCn O 5 1
EXPLANATION
Outline of principal productive
sedinantary basins
124'
TRINITV z-,,-^,
r ?. J^ T^^JW "'W >■ SIERRA
if
Oil f iaid
^1
ffl-40°
119°
p LAKE ; I -V Ws,) \\! Av: <^ _^.; :
v\._/'\.vol2!1>;X J^'ri. dora'dq,- N;^.
.^^alpine'
39°
\sonoma<^naA' -t^.
\
K.^-
38
tf
\
118°
'H-l'Cr*^* ' 't^\ , TUOLUMNE 1^\moNO\ +38°
Francisci>t-^ \'/.J — '
SANTA ss^ f-f \i .-^^ y ■
SANTA CRUZ
3
Bibhop "v
■^^A^-.
.SAN
36
<^.. -^^
'> \
C \\ ' N Y O <5, \.
TAi.ARE ^ A -VK \
'\
-OB
NT«5ha|mA-i-::^sA
SAN BERNARDINO '^
50
I I I
^j^,^^ DESERT '■->
3-'iSS^'S^^^^X ' 1''
SIDE \
J
LOS ^GELES-K3--'^i,_'l'_-
SAN DIEGO
117°
115°
Figure 47. California oilfields.
by mid-1965, and may increase to 1,000,000 barrels per day in the next
few years. It has been estimated that the need for crude oil in Cali-
fornia will increase about 3.8 percent annually through the year 2000.
The gravity of California crude oil ranges from 6° to 60° API, but
347,800 barrels per day, or 42 percent of the State's production in
January 1965, was heavy crude below 20° API gravity. The price
received by the producer at the well depends largely on the gravity.
It ranges from $1.07 to $3.42 per barrel at present and averages about
$2.47.
Along with the oil, the State's wells produce about 2.9 million barrels
of water per day which must be disposed of according to the require-
294
MINERAL AND WATER RESOURCES OF CALIFORNIA
124''
123°
122'' 121'
«"~7
( S I S K ||y o\u/ — J Q,
i W-K A K» A -^i W\"^ O M O Jo C
4,.^ \Mdt^(b^TA/NSn^
> ...11 i ^<
EXPLANAT I ON
Outline of principal productive
stdiMntary basins
J
shAtaV
TRINITY' /"^^ ■ "YSSEJiX i
.-^aCiJ CASCAf>E \ <\ I
eSf^'J^li^e y, SIERRA
Large gas f ie Id
Saa I I gas f le Id
+
39"
\
118°
.^ "><i^'
SANTA CRU2-«S SANTA S^ rX \\ / ^ ^ i \ .Biri»t. V
\SON0MA(^ N
rrancurol.
IOn6\ —^ 38°
\
117°
\Vv ^FRESN
.-J-^
w
'> \
' jK^^^
I. '\ > N Y O ^ \
3e°+
122°
\
.1.5°
\
MOJAVE -|--^35°
SAN BERNARDINO •^^
DESERT
121°
50
_L_
150 MILES
_l
120°
, , I . %^^ CSALTON ) -=.33°
+ \ + I ^^'^ "'"'° CtroughW
119° 118° M{,s»>D"«° _^aV---^- r
115°
116°
117°
FiouKE 48. California gasfields and principal productive sedimentary basins.
ments of the State AVater Pollution Control Board. Both the pro-
duction and disposal of water increase the cost of producing oil.
Forty-six pools or fields in the State are today partially or fully
unitized, the first unit having been formed at the Kettleman North
Dome field in 1931. Nineteen pools or fields, although not unitized,
are operated essentially as units.
The State Oil and Gas Supervisor, Division of Oil and Gas, is
charged with the responsibility of carrying out the provision of State
laws for the conservation of oil and gas. Among other things, these
laws provide for supervision of operations so as to prevent, as far as
possible, damage to underground oil and gas deposits from infiltrating
water, and the loss of oil and gas; these laws also prohibit the un-
reasonable waste of gas. The Division also supplies oil and gas field
maps, publishes detailed descriptions of most fields in the State, and
provides statistics on production.
MINERAL AND WATER RESOURCES OF CALIFORNIA 295
The Conservation Committee of California Oil Producers recom-
mends schedules for production from 75 pools, based on determinations
by engineering studies of what is considered the Maximum Efficient
Rate (MER) of production. The Committee also provides production
statistics.
The California Division of Mines and Geology, the U.S. Geological
Survey, and the American Association of Petroleum Geologists have
published many maps and articles concerning the geology and occur-
rence of oil in the State. The last also provides exploration statis-
tics. On Federal lands the Conservation Division of the U.S. Geo-
logical Survey supervises drilling and producing operations and deter-
mines and collects the royalty.
Information used in this chapter concerning the petroleum industry,
the geology, and the occurrence of oil in the State has appeared m
published reports too numerous to list; it is gratefully acknowledged.
A selected list of references is included with this report.
United States Rank as World Producer of Oil
The demand for petroleum products in the United States in 1964
was 11.3 million barrels daily. This demand was met largely by
domestic production of 7,664,000 barrels of crude oil and gas con-
densate, by the production of 1,147,000 barrels of natural gasoline and
other liquid petroleum products, and by imports of 2,260,000 barrels
of crude oil and products. Only 202,000 barrels per day of products
and crude oil was exported.
For many years until the mid-1940's, the United States produced
approximately two-thirds of the oil in the world. In recent years,
however, imports of crude oil and refined products into the United
States have increased while exports have decreased, so that imports
have exceeded exports since about 1948. In 1964, the United States
produced about 33 percent of the free world's production, and about
27 percent of the entire world's production which has been estimated
at 28.1 million barrels daily.
California's Rank in United States Production
California was the major oil producing state from 1903-1914 and
1923-1926. It was second to Texas until 1958 when Louisiana ex-
ceeded California, mainly because of the development of large pro-
duction in southern Louisiana, including offshore. California now
ranks third in both current crude oil production and reserves (table
35).
Geologic Occurrence
Commercial quantities of oil and gas occur imder pressure in the
interconnected pores of reservoir rocks in pools or fields. All oil
miderground contains some dissolved gas, so when oil is mentioned
the contained gas is included also. The interconnected pores between
the grains of sand or conglomerate comprise the space which holds
most of the oil in California as in many other oil regions. It is esti-
mated that 98 percent of the oil in the State occurs in rocks of those
types. In addition, weathering, solution, chemical changes, and frac-
turing also create porosity, and some oil is produced in California from
296
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA 297
fractured cherts, fractured shales, fractured sandstones, and from
weathered and fractured basement rocks beneath the sedimentary
rocks.
The pore spaces in most sedimentary rocks more than a short dis-
tance beneath the surface were filled with water at some time in their
history, so in oil reservoirs they generally contain what is called inter-
stitial water as well as oil.
For commercial production to be obtained, the reservoir rock must
also be permeable as well as ix)rous. Permeability is the measure of
the ease with which fluids move through the interconnected pore
spaces.
The original pressure in most California reservoirs is roughly
equivalent to that which would be exerted by a vertical column of
water extending nearly to the surface, but it exceeds that pressure in
some fields.
"Wlien the drill penetrates the reservoir rock and any drilling fluid
in the hole is partially or completely removed, the reservoir energy
causes the oil to move into the hole. The gas expands, the fluid moves
toward the surface, and oil may flow from the well (a "gusher" if the
flow is large and uncontrolled). If the fluid does not reach the sur-
face, it is removed by pumping or by other mechanical means. The
gas-free oil in stock tanks at the surface occupies less volmne than it
did underground because the compressed gas dissolved in the oil in the
reservoir escapes from the oil as the pressure is reduced from that in
the reservoir to that in the tank.
How the oil and gas were formed, how they move (oil and gas are
migratory fluids), and how they accmnulate at the places where they
are now found — the origin, migration, and accumulation — is still the
subject of much scientific speculation, although a great deal is now
known about cliaracteristics of the traps in which they have accumu-
lated, as a result of studies of thousands of oil fields. It is now widely
accepted that commercial petroleum is derived from the organic re-
mains of plants and animals that were deposited in a low-oxygen,
reducing environments in marine sediments, principally fine-grained
muds, but also in sediments deposited in brackish to fresh w^ater (Hed-
berg, 1964). The chief sources of oil and gas in California are be-
lieved to be the thick organic shales (consolidated muds) so wide-
spread in marine sedimentary rocks primarily of Tertiary age, but also
of Cretaceous age (Hoots, 1943).
It is believed that oil, along with water, escapes from the muds as
they are compacted, and moves into coarser sediments through which
it moves laterally into the traps in which it now occurs. Vertical
migration, possibly along faults, may account for the present location
of some of the oil at shallow depths in some California fields (Hoots,
1943).
Regardless of the processes involved, oil usually moves toward
higher elevations because these are areas of lower pressure, and be-
cause oil is lighter than water. It accumulates in traps which may be
classified as structural, stratigraphic, and combination (strati-struc-
tural). A trap involves a porous reservoir rock, an overlying im-
permeable cap rock, and a barrier in the reservoir which prevents
further updip or lateral movement of the fluids. In traps that con-
tain free gas, oil, and water, the fluids are arranged in approximately
67-1164 O— 66— pt. I 20
298 MINERAL AND WATER RESOURCES OF CALIFORNIA
horizontal layers — gas being the lightest, at the top, then oil, and
then water. The water almost always moves slowly into areas in
which the pressure has been reduced by removal of the oil, and this
movement may assist in recovering more of the oil in the reservoir.
Levorsen (1954) defines a structural trap as one whose upper
boundary has been made concave, as viewed from below, usually by
folding or faulting or both, of the reservoir rock ; a stratigraphic trap
as one in which the chief trap-making element is some variation in
the stratigraphy or lithology of the reservoir rock; and a combination
trap as one in which both causes are in approximately equal propor-
tions. Most stratigraphic traps in California involve some element
of structure. Commonly, multiple productive sands separated by
impermeable shales are present in structural traps in California, an
obvious favorable circumstance for additional accumulations.
Environments favorable for a source of oil are not necessarily favor-
able for the development of reservoirs, so oil occurrence depends in
part on a favorable relationship of the two. Normally, either without
the other does not result in a commercial oil occurrence (Weeks, 1958).
Hedberg (1964) stated that California is in one of the two principal
belts of oil occurrence in the world. In the United States, the north-
south belt also includes the major oil field areas of the Rocky Moun-
tains, the Mid-Continent, and the Gulf Coast regions.
California is also in a mobile belt bordering the Pacific. Traps in
which oil and gas may accumulate are commonly smaller but more
numerous in such regions than in more geologically stable regions.
The petroliferous provinces of the world, including California, are
in sedimentary basins — geologically depressed areas in which great
thicknesses of sedimentary rocks that were deposited in the interior
of the basin thin toward the edges.
In California, most of the oil is obtained from marine sands and
conglomerates of Miocene and Pliocene ages (fig. 49) . Lesser amounts
come from sands and conglomerates of Eocene, Oligocene, and Pleisto-
cene ages and from fractured rocks of Miocene age; still smaller
amounts come from sands of Late Cretaceous and Paleocene ages, and
from fractured and weathered basement rocks of pre-Tertiary age.
Gas is produced along with the oil from rocks of the previously men-
tioned ages, but most of the dry gas is obtained from rocks of Late
Cretaceous, Paleocene, Eocene, and Pliocene ages. The surface evi-
dence of many geologic structures, both anticlines and faults, has re-
sulted from the mid-Pleistocene deformation. Many fields are located
on prominent hills or ridges which approximate the location and
shape of the anticlinal structure of these hills or ridges because the
anticlinal hills rose more rapidly than streams could erode and level
them.
Economic Factors Affecting Exploration
The principal economic factors affecting exploration (including the
drilling of exploratory wells) for oil and gas are, of course, the price
(fig. 50), market demand, and accessibility to markets for the raw
material at the time and in the foreseeable future in a free economy —
in other w^ords how much of the production, if found, can be sold and
at what price.
MINERAL AND WATER RESOURCES OF CALIFORNIA
299
EPOCH
LOS
ANGELES
oc.
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zee
SALINAS-
CUYAMA
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z
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oc
ae
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Pie istocene
•
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•
•
•
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01 igocene
•
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Pa leocene
•
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Late
Cretaceous
•
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pre-Tert iary
basement rocks
age uncertain
•
•
•
EXPLANAT ION
Oi I product ion, large
Qi I product ion, sma 1 1
to moderate
Gas production, large
Gas product ion, sma 1 1
to moderate
Figure 49. California oil and gas production in principal sedimentary basins,
according to geologic age of rocks.
Commonly, exploration has decreased in times of economic stress,
lower prices, or an over-supply of oil, notably during the years of the
great depression in the early thirties when exploration virtually
ceased. Even in the thirties, however, the application of new explora-
tory tools such as the reflection seismograph was instrumental in caus-
ing farsighted organizations to search for prospects and to acquire
rights to lands.
Following the development of large flowing production in the twen-
ties, principally from the Long Beach and Santa Fe Springs fields in
1929, voluntary curtailment of production was generally accepted and
has continued to some extent to the present, except for regulation of
production by the Federal government from 1933 to 1935.
Prior to World "War II, and occasionally since then, production of
crude oil in California was greater than the demand, and large quan-
tities of crude and products were sold on the world's markets, often
at depressed prices. Since World War II, however, the local demand
for both oil and gas has increased greatly as a result of industrial
and population growth, and in recent years production in California
has been insufficient to meet the local demand. Large and increasing
amounts of gas have been brought into the State since 1947 through
gas transmission lines from Texas, New Mexico, and Canada, and
300
MINERAL AND WATER RESOURCES OF CALIFORNIA
since 1951 large and constantlj^ increasing amounts of crude oil and
petroleum products have been imported from other states and foreign
sources (fig. 51). Among the consequences of this change in supply
and demand are a relative stabilization in the price for crude oil but
an increase in the price for gas. This latter increase has provided an
incentive for expanded exploration for gas in the Sacramento sedi-
mentary basin.
,. Natural gas^
«
^
o
o
r~
oo
CO
o
oo
CO
oo
OJ
CM
CO
a)
CO CO
oi ay
Figure 50. Average price of California crude oil and natural gas.
-300.000
s
ources: Gas
-Conservat ion
3-^
Committee
of Cal if .
oi 1
/^\ ' /
producers :
Oi 1, U.S.
Bur .
y* ^<^^^
Mines and
others
•/^
^
>-
_J
-200.000
/•
2-
<
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«n
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\ • * /
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-100.000
•
•
•
•
•
/i
1-
• 1 1
1 f
1 1 1
1 1 1
1 1 1
1 1 1
<
LU
CD
1947
1950
1955
1960
1964
FiGUKE 51. Imports of crude oil and natural gas into California.
MINERAL AND WATER RESOURCES OF CALIFORNIA 301
Perhaps the most remarkable feature of the California oil-produc-
ing industry is the small size of the productive area that has produced,
and still contains, so much oil (Hoots, 1943). About 13.25 billion
barrels of oil has been produced prior to 1965 from approximately
330,000 acres of productive land, or y^ of 1 percent (1/333) of the area
of ithe State. The average recoveiy of 40,000 barrels per acre to date,
and the estimate that this will increase to more than 53,000 by produc-
tion from the presently known fields, is extremely high in comparison
to other large areas in the United States. Several fields in the Los
Angeles and Ventura basins have produced more than 100,000 barrels
per acre, and the Long Beach field has yielded aJbout 500,000 barrels
per acre. The yield of the average well in California during its pro-
ductive life is expected to be 260,000 barrels, 3.5 times the average of
wells in the rest of the United States. These large recoveries provide
an incentive for exploration, and large rewards often result from a
discovery.
Political considerations and Federal, State, and local laws and ordi-
nances, also affect exploration. Eestrictive provisions such as pro-
hibitions against drilling within cities, or uncertain titles to offshore
lands, at least delay exploration. Notable examples of the first were
restrictions against drilling in Los Angeles and in Long Beach. After
the restriction against drilling in Los Angeles was removed in 1950
exploration was intensified and several large fields have been dis-
covered. The restriction agamst drilling at Long Beach, because of
the fear of subsidence, was partially the cause of the delay in devel-
oping the huge East Wilmmgton field. An example of the second
type is the more than 10-year delay in the leasing of a large part of the
favorably regarded submerged lands offshore from southern Califor-
nia, because the Supreme Court did not decide the ownershij) of the
mineral rights in these lands, whether State or Federal, until early
1956. Even though it was possible to explore these submerged lands
by geophysical methods and, with certain restrictions, to drill wells
for geologic information, it had not been possible to complete the
exploration by testing wells to determine their productive capacity.
Urbanization and the consequent increase in land values has locally
retarded exploration and was a factor in the abandonment of the larg-
est parts of some fields, notably the Los Angeles and Salt Lake fields
in the Los Angeles basin. Exploration by ordinary seismic methods
in urban areas is made almost impossible by ordinances and fear of
large claims for alleged damages. Exploratory wells must often be
directionally drilled from drill sites which may be costly and some-
times difficult to obtain.
Prior to about 1910, most wells in California were drilled with cable
tools, equipment not well adapted for drilling to depths greater than
in the old shallow fields in the relatively unconsolidated rocks in the
oil regions in the State. The introduction of rotary tools soon per-
mitted deeper exploratory wells, and discoveries were made at greater
depths.
The drilling of exploratory wells has been greatly aided since the
1920's by many improvements in the quality of equipment and in the
technique of drilling. The principal improvements in technique are
the ability to obtain cores of the rocks, to control the quality of the
302 MINERAL AND WATER RESOURCES OF CALIFORNIA
drilling fluid, and to evaluate the fluid-yielding capacity of the rocks
without installing casing in the hole. Evaluation may be made by
numerous devices which are lowered by cables, or by testers which
permit the obtaining of samples of the fluids in tlie rocks and the ap-
proximate determination of the volume of production that may be
expected. The ability to survey holes, which was pioneered by Alex-
ander Anderson at Long Beach, and the ability to drill directionally to
predetermined locations are of great assistance. Directional drilling
has aided exploration because wells can be drilled beneath built-up
areas, beneath closed areas, beneath mountainous land in which access
roads would be very costly, and from land to favorable locations be-
neath the ocean. Hydraulic fracturing has been used to create per-
meability in the reservoir rocks, and in at least one local area has
resulted in a discovery.
History of Discovery and Development
That California is a petroliferous region was indicated as early as
1542 when Cabrillo landed near Carpinteria in Santa Barbara County
and found oil which had drifted from seeps beneath the ocean onto
the beaches. In 1769, the Portola expedition found Indians using tar
from the Eancho La Brea tar pits near Los Angeles. Portola used
this tar as fuel for camp fires. Heizer (1943) mentions that explorers
in 1775 reported that Indians used tarry material (chapapote) from
springs near San Luis Obispo for caulking boats, and the Yokut
Indians used oil from seepages in the San Joaquin Valley.
In the 1800's, many seepages of oil and of ^as, and other near-surface
indications such as gas in water wells or railroad tunnels, were found
in the provinces on land which are now productive. Oil odors, oil
slicks, and floating tar are evident on the water off the coast, and seeps
off Redondo Beach and west of San Miguel Island are shown on maps
by the U.S. Coast and Geodetic Survey. Many other evidences of
these oil seeps have been observed on the water off southern California,
tar and globules of oil have been observed in samples of the shelf
sediments, and tar mounds on the ocean floor near Santa Barbara
beneath 90 feet of water have been i)hotographed by Vernon and
Slater (1963).
Seepages are important because they indicate the presence of a
source rock. Nearby all of the early fields within the oil provinces
in the world have been found by drilling near seepages, but after
the early stages most fields have been found following geological and
geophysical studies. However, even in recent years many fields have
been found by random drilling.
Discovery hy prosjjecting near seepages, 1865-1907
Many of the early wells in search of oil in California were drilled
near seepages in the central and northern parts of the State. The
first oil produced in California amounted to a few barrels from
shallow wells on the Mattole River in Humboldt County. It was
shipped to San Francisco in 1865. Several small producing wells
were drilled near Ojai in the Ventura basin, including one said to
be capable of producing 15 to 20 barrels ]>er day in 1866, but there
M-as no market for the oil. The first truly commercial well in the
MINERAL AND WATER RESOURCES OF CALIFORNIA 303
State (Pico 4) was completed by the California Star Oil Works Co.
ne^r Newhall in 1876, It produced 30 ban-els per day from a depth
of 300 feet, and later made 150 barrels per day after it was deepened
to 600 feet. The first California pipeline was laid in 1879 to carry
this oil to the first California refineiy near Xewhall.
Several fields were discovered in the latter 1800's, some of the present
major oil companies were organized, and the first tankship was put
into use. The fii'st large well was completed in 1892 by the Union
Oil Co. near Santa Paula, and the JjOS Angeles field was discovered
in 1892 by E. L. Doheny. The Ix>s Angeles field was the site of the
first town-lot drilling in the State, and it soon became the State's
largest producer. Thirty-two fields and some 2.5 billion barrels of
oil were found in California during this period (Hoots, 1954).
Some spectacular gushere — spectacular because they flowed out of
control — were drilled. The famous Lakeview No. 1 gusher in tlie
Midway-Sunset field flowed 'out control for li/^ years in 1910-1911
from a depth of 2,225 feet. It produced as much as 68,000 barrels
per day, and made a total of about 8.25 million barrels before sand
entered the hole and choked off the flow. This is said to be the largest
well in the United States. Large flows came from other wells, such
as 12,000 barrels per day from a well in the Orcutt field near Santa
Maria, and 10,000 to 20,000 barrels per day from early wells in the
Midway-Smiset field. A well drilled in ]Midway-Smiset by the Lake-
view Oil Co. is said to have flowed as much as 50,000 barrels per day.
Other spectacular wells were those that blew out and caught fire.
Many wells capable of large production have been completed in more
recent years, but they are brought in under control ancl .are produced
at only a fraction of their potential.
Discoi^ery frimarily hy the use of geology^ 1908-35
Beginning about 1900, geologic mapping of rocks at the surface
began to be used in a small way in the search for oil, but it was not
until 1908 that this method resulted in the discovery of several fields
(Hoots, 1954) . Early studies of the geology by personnel of the Cali-
fornia State Mining Bureau (now California Division of Mines and
GeologjO^ the U.S. Geological Survey, the universities, and by mem-
bers of the oil industry greatly increased the knowledge of the geo-
logic conditions favorable for accumulation, and thus aided explora-
tion (fig. 52).
The use of surface geologic mapping, and the interpretation of
surface topography, in order to find anticlinal folds and fault traps,
Avas accompanied by a gradual increase in geological interpretation of
information obtained during drilling — known as subsurface geology.
These came to be accepted as exploration tools by the oil industry.
Random wildcat drilling continued to supplement the search for oil,
but it was usually conducted along production-trend lines, on some
supposed favorable topographic expression, or because of a showing in
a nearby well. Fifty-three fields and about 7.6 billion barrels of oil
were found in California during this period 1908-1935 (Hoots, 1954).
Improved drilling techniques were partially responsible for some of
these discoveries, as wells could now be drilled to depths greater than
early wells on the same structure — for example, in the Kettleman
North Dome field. Many of the large fields in the productive basins
304
MINERAL AND WATER RESOURCES OF CALIFORNIA
BARRELS
1,500,000,000 1
1.000.000,000
500.000.000-
100.000,000 :
Hoots, 1954
FiGUBE 52. Oil discovery record for California by individual years.
were discovered during this period, includino; the large Long Beach,
Santa Fe Springs, Huntington Beach, and Wilmington fields. The
latter was discovered by a small edge well in 1932 ; at the time it was
assumed to be only an extension of the Torrance field.
Discovery by the lose of geology and reflection seismovietry^ 1936 to
present
Since about 1936, exploration prior to drilling has been carried on
mainly by the use of geolog}^ (surface and subsurface) and by the
use of geophysical methods, principally the reflection seismograph.
Geophysical methods which measure certain physical properties of
rocks that are related to potential traps in reser\'oir rocks were first
used in California in 1924. The methods used in the early stages did
not result in the discoveries of new oil and gas fields, although they
did contribute to the knowledge of the general geological structure of
the oil-productive basins.
The reflection seismograph, however, has proved to be successful in
finding traps favorable for the accumulation of oil and gas in Cali-
fornia, It also supplies data that is useful for subsurface geologic
studies. No method has been found except the drill that can locate
commercial amomits of oil directly. A small gas field (Paloma) was
discovered in 1934 in the San Joaquin basin a result of reflection
seismograph suiweys, and this was followed in 1936 by the significant
discovery of the Ten Section oil field in the central part of the San
Joaquin basin, also as a result of seismic maping. The latter discovery
not only demonstrated that anticlinal folds concealed beneath the thick
alluvial fill of the San Joaquin basin could be found by the reflection
seismograph, but also that thick Miocene sands provide adequate
MINERAL AND WATER RESOURCES OF CALIFORNIA 305
reservoir rocks beneath the valley floor. The prolific main part of the
Wilmington field was discovered in 1936 as a result of reflection seis-
mograph surveys.
The importance of stratigraphic traps had been emphasized by the
discovery of the huge East Texas field in 1930, and the applicability of
this new phase of geologic exploration to California was apparent.
The search for traps of this kind resulted in the discovei-y of the Santa
Maria Valley field in the Santa Maria basin in 1934, in the finding of
the prolific East Coalinga Eocene field in the San Joaquin basin in
1938, and later in the discovery of other fields in stratigraphic traps.
The firsit major discoveries in a previously nonproductive sedi-
mentai-y basin since the days of prospecting near seepages were made
in 1947-1949 when the San Ardo, Russell Ranch, and South Cuyama
fields were found in the Salinas-Cuyama basin. Stratigraphic think-
ing played a large part in the discoveiy of these fields. Three small
fields — Oil Creek, La Honda, and South La Honda — were discovered
in the period 1953-1959 in the Santa Cruz (La Honda) basin, largely
as the result of surface and subsurface geologic studies. Beginning in
the late 1800's, several small doubtfully commercial wells had been
drilled in this basin, but the discoveries in the 1950's first established
commercial production.
About 3.2 billion barrels of oil was found in California in the period
1936-1952 (Hoots, 1954). The estimated amount of oil discovered
annually from 1908 to 1952 and the methods of exploration which
accounted for these discoveries is shown in figure 52 after Hoots
( 1954) . This figure emphasizes the fact that the annual discovery rate
has fluctuated widely, to a large extent due to the application of new
methods or concepts of exploration. It is somewhat misleading, as
all the oil in any one field is allocated to the year of first discovery
of the field. This figure does, however, bring out the poor discovery
record during the depression from 1929 to 1935 and the World War II
period from 1940 to 1947. In recent years, the geological and geo-
physical methods employed in exploration have become so intermingled
that it is futile to attempt to separate the methods that have led to
many discoveries. However, most exploratory wells in California's
highly explored onshore regions have been located by subsurface
geological studies, assisted by some geophysical information where
wells are sparse.
According to Hoots (1954), about 13.3 billion barrels of oil had
been found in the State to the end of 1952. If this estimate is used,
it appears that about 4.1 billion barrels was found during the period
1953-1964, as production to the end of 1964 plus proved reserves at
that time totaled 17.4 billion barrels.
Figure 53 shows the total number of exploratory wells drilled
annually in the State for oil and gas in the period 1942-1964. It also
show^s the percentage of these wells that were successful in finding oil
or gas, and the percentage of success in terms of footage.
Development drilling — the drilling of proved locations Avithin known
fields — has been sporadic since the early days of the oil industry in
California. This sporadic drilling is due mainly to : (1) the develop-
ment of new fields following discovery, (2) the price and demand for
306
MINERAL AND WATER RESOURCES OF CALIFORNIA
the crude of the quality that can be expected, (3) lease requirements,
and (4) the operator's desire to maintain or increase his production.
An average of about 2,000 development wells were drilled annually
during the 4-year period 1961-1964.
As in other oil-producing regions, a large part of the production
comes from the "giant" fields — those fields which are expected to pro-
duce more than 100 million barrels. There are 40 of these fields in
California (table 36). These fields produce nearly three-fourths of
California's oil and contain more than 80 percent of the estimated
proved reserves.
Table 36. — Grant ^ oilfields in California
[Reserves from Oil and Gas Journal, v. 63, no. 4, Jan. 25, 1965, p. 155; others from Conservation
Committee of California Oil Producers]
Basin and field
Dailyaverage
production
in 1964
Number of
wells produc-
ing in 1964
Production
in 1964
(thousand
barrels)
Accumula-
tive produc-
tion to
Jan. 1, 1965
(thousand
barrels)
Estimated
remaining
crude oil
reserves as of
Jan. 1, 1965
(thousand
barrels)
Los Angeles sedimentary basin:
Wilmineton .
96,337
43, 977
19, 669
14, 797
12, 507
8,373
7,954
6,953
5,529
5,470
5,001
4,223
3,202
31, 533
10, 568
8,828
630
50, 675
27, 724
26, 813
23,256
22, 791
20,099
9,499
8,848
8,205
7,511
7,432
6,765
6,227
6,176
6,136
5,702
4,612
4,553
7,356
4,394
4,312
27, 379
19, 513
2,583
1,712
601
710
1,000
305
254
254
470
424
636
269
285
1, 125
472
353
27
4,376
80
3,592
2,342
1,300
2,584
689
178
220
1,025
43
268
774
552
597
418
65
350
274
208
276
874
203
35, 259
16,095
7,199
5,415
4,577
3,064
2,911
2,545
2,023
2,002
1,830
1,545
1,171
11,540
3,.867
3,231
231
18,546
10, 147
9,813
8, 512
8,341
7,356
3,476
3,238
3,003
2,749
2,720
2,476
2,279
2,260
2,245
2,087
1,687
1,666
2,692
1,608
1,578
10,020
7,141
1, 013, 488
730, 628
247, 966
299, 510
843, 301
207, 245
236, 953
171,659
587, 995
145, 178
164, 714
87, 693
176, 036
693,997
106, 705
87,885
101, 723
947, 890
408, 523
393, 479
549,952
524, 291
109, 401
91, 417
124. 270
271, 471
94, 027
94,344
440, 395
105, 937
96, 634
149, 464
88, 449
105, 100
112, 566
108, 167
127, 118
138,982
144, 989
175, 628
586, 422
Huntington Beach
150, 284
Inglewood.
53,552
Brea-Olinda -
49,637
Long Beach -
36,602
Coyote West
22,590
Domingquez
27, 957
Seal Beach .
28, 190
Santa Fe Springs. -
26, 929
Richfield
14,838
Torrance . .
25, 232
Coyote East
12,386
MontebellJ .-
9,050
Ventura sedimentary basin:
120, 956
South Mountain
48,180
28,082
Elwood
8,098
San Joaquin sedimentary basin:
Midwav-Sunset
164,566
Coalinea East Extension
K!ern River
111,016
56, 091
Coalinea -
a3,309
Buena Vista
90,785
Belridee South
27, 412
Cymric ..
25, 152
Coles Levee North ..
35, 715
Elk Hills
1, 031, 108
Lost Hills
■ 10, 546
Greeley
20, 570
Kettleman North Dome
Kern Front —
Edison
34, 624
16, 082
23,317
Mount Poso
26, 932
Fruitvale
86, 362
Rio Bravo
29, 992
McKittrick
13, 260
Santa Maria sedimentary basin:
Cat Canyon West
31,764
Orcutt
7,918
Santa Maria Vallev
21,008
Sahnas-Cuyama sedimentary
basin:
San Ardo
97, 205
Cuyama South
108, 332
Total, 40 fields
601, 529
32,768
220, 145
11,305,170
3, 382, 051
' One hundred million barrels or more of recoverable oil.
MINERAL AND WATER RESOURCES OF CALIFORNIA 307
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308
MINERAL AND WATER RESOURCES OF CALIFORNIA
In 1964, 42,000 producing oil wells in the State yielded 817,395
barrels per day, or an average of 20 barrels per well daily (fig, 54).
However, production increased toward the end of the year and reached
830 thousand barrels per day in December.
In recent years, most large flowing wells are allowed to produce at
only a part of their potential daily production in order to conserve
reservoir energy, to increase the efficiency of production, and to in-
crease the amount of oil that can ultimately be recovered from the
reservoir.
Unitization or some form of cooperative agreement is very desirable
for efficient production, for conservation, and for maximum ultimate
recovery, especially in California with its diversified land interests.
Unitization or such agreements are necessary for secondary recovery
operations. More than 65 units or agreements are now in effect in the
State, and several more are being formed.
Natural Gas
Gas, like oil, is believed to originate from organic material deposited
principally in marine sediments, but why only gas is found in some
large regions such as large parts of the Sacramento Valley is unknown.
It seems probable that only gas was originally generated in such re-
gions (Hedberg, 1964) . It has been suggested that gas rather than oil
may originate due to differences in the organic source material or in the
depositional or post-depositional environment.
Gas produced with water from shallow wells was furnished to
Stockton in the 1850's. Later, in the early 1900's, many California
1.000.000
800.000
o
^
OJ
cr>
OS
a)
^ in
(O CO
en a>
Less than 10,000
barre Is da i ly 1861 -
99
FiGUBE 54. California crude oil production.
CO
o
<u
o
n)
ID
(D
o
'\:
/:
1
O
<
o
<
MINERAL AND WATER RESOURCES OF CALIFORNIA 309
cities were supplied from gas zones in oil fields. Considerable gas
lias been produced from these dry gas zones in oil fields since 1909
when a gas zone was discovered in the Buena Vista field (fig. 55) in
the San Joaquin basin. A prolific gas zone was discovered in the
nearby Elk Hills field in 1919 and it is said that one well in that field
produced more gas than any other single well in the country prior to
1940.
The first dry gas field of importance was discovered at Buttonwillow
(fig. 55) in the San Joaquin basin in 1927, but this discovery was soon
overshadowed by the completion of wells producing large amounts
of wet gas from the gas cap at the Kettleman North Dome field. In
1933, the first high-pressure gas well in the Sacramento basin (fig. 48)
was completed adjoining Sutter (Marysville) Buttes. A few addi-
tional rather small dry gas fields were found prior to 1936, but the
first two large dry gas fields, McDonald Island and Rio Vista (fig. 56),
were discovered in the Sacramento basin in that year. The latter has
produced 2.25 trillion cubic feet of gas, more than one-half of the
State's dry gas production. It is by far California's largest gas field.
Many dry gas fields have beeii found in the Sacramento basin (figs.
48, 56) since 1936. Exploration there increased in the late thirties,
was interrupted by World War II, and has been aggressively pursued
since then, encouraged by the increasing price for gas (fig. 50), which
is now about $0.30 per tiiousand cubic feet at the well. Four dry gas
fields (fig. 55) have been found offshore in the Ventura basin in recent
years. Another new offshore oil field in that basin yields dry gas from
one sand.
Large amounts of wet gas accompanying the production of oil were
wasted in the early 1900's, especially from the town-lot fields of Hunt-
ington Beach, Long Beach, and Santa Fe Springs (fig. 55) in the
Los Angeles basin- Also, large amounts of wet gas were wasted from
the Ventura and Kettleman North Dome fields. Wells in those fields
flowed at large rates, and the amount of gas produced along with the
oil was far in excess of available outlets. At that time the price of gas
was low, and the present State laws which j^rohibit the unreasonable
waste of gas were not passed until 1929. Beginning in the 1930's, the
amount wasted decreased to 5 to 10 percent. The wastage now is less
than 1 percent of the wet gas and practically none of the dry gas.
Since 1947, when gas was first imported into California, the demand
has exceeded the amount produced in the State. Increasing amounts
have been brought in from Texas and New Mexico, and later from
Canada (fig. 51), so that now 64 percent of the gas consumed here
comes from outside the State.
Gas production and the number of gas wells have increased rapidly
in recent years (fig. 57), and 896 billion cubic feet was produced in
California in 1964. About two-thirds was wet gas accompanying oil.
However, more than one-third of the gas from oil wells was returned
to the sands to increase the recovery of oil, so that the net withdrawal
of wet gas in 1964 was 384 billion cubic feet. Per barrel of oil, wet
gas production was 2,020 cubic feet gross and 1,280 cubic feet net. Dry
gas production in 1964 was 291 billion cubic feet from 898 producing
wells. The average heating value of this dry gas is approximately
1,000 Btu per cubic foot.
-i-— I-
-^ -.
W '
MINERAL AND WATER RESOURCES OF CALIFORNIA 309
cities were supplied from fjas zones in oil fields. Considerable gas
lias been produced from these dry <^as zones in oil fields since 1909
when a gas zone was discovered in tiie Buena Vista field (fig. 55) in
the San Joacjuin basin. A prolific gas zone was discovered in the
nearby Elk Ilills field in 1919 and it is said that one well in that field
produced more gas than anv othci- sinirle well in the country prior to
19-10.
Tlie first dry gas field of importance was discovered at- Buttonwillow
(fig. 55) in *^he San Joacpiin basin in 19i>7, but this discovery was soon
overshadowed t)y tlie completion of wells i)roducing large amounts
of wet gas from the gas cap at the Kettleman North Dome field. In
193'>, the lirst high-pressure gas well in the Sacramento basin (fig. 48)
was completed adjoining Sutter (Marysville) Buttes. A few addi-
tional ratlicr small dry gas fields wei-e found ])ri()r to 19J56, but the
first two large dry gas fields, AfcDonald Island and Rio Vista (fig. 50),
were discovered in the Sacramento basin in that year. The latter has
])roduced 2.25 trillion cubic feet of gas, more than one-half of the
State's dry gas production. It is by far California's largest gas field.
Many dry gas fields have Ix^en found iri the Sacramento basin (figs.
48, 56)' since 1936. Exploration there increased in the late thirties,
was interrupted by "World "War II, and has been aggressively pursued
since then, encouraged by tlie increasing jirice for gas (fig. 50), which
is now about $0..'50 i)ei' tiiousand cubic feet at the well. Four dry gas
fields (fig. 55) have lieen found offshore in the Ventura basin in recent
yeai-s. Anothei- new offshore oil field in that basin yields dry gas from
one sand.
Large amounts of wet gas accompanying the production of oil were
wasted in the early 1900*s, especially from the town-lot fields of Hunt-
ington Beach, Long Beach, and Santa Fe Springs (fig. 55) in the
Los Angeles basin- Also, large amounts of wet gas were wasted from
the Ventura and Kettleman Xorth Dome fields. "Wells in those fields
flowed at large rates, and the amount of gas ])roduced along with the
oil was far in excess of available outlets. At that time the price of gas
was low, and the present State laws which jirohibit the unreasonable
waste of gas were not passed until 1929. Beginning in the 1930's, the
amount wasted decreased to 5 to 10 percent. The wastage now is less
than 1 percent of the wet gas and jiractically none of the dry gas.
Since 1947, when gas was first im])orted into California, the demand
has exceeded the amount i)roducP(l in the State. Increasing amounts
have been brought in from Texas and New Mexico, and later from
Canada (fig. 51), so that now 64 percent of the gas consmned here
comes from outside the State.
Gas production and the number of gas wells have increased rapidly
in recent years (fig. 57), and 896 billion cubic feet was produced in
California in 1964. About two-thirds was wet gas accompanying oil.
However, more than one-third of the gas from oil wells was returned
to the sands to increase the recovery of oil, so that the net withdrawal
of wet gas in 1964 was 384 billion cubic feet. Per barrel of oil, wet
gas production was 2,020 cubic feet gross and 1,280 cubic feet net. Dry
gas production in 1964 was 291 billion cubic feet from 898 producing
wells. The average heating value of this dry gas is approximately
1,000 Btu per cubic foot.
310 MINERAL AND WATER RESOURCES OF CALIFORNIA
Figure 56. Northern California dry gas fields.
MINERAL AND WATER RESOURCES OF CALIFORNIA
311
Ll.
u
m
o
2
O
m
1905
1915
1925
1935
1945
1955
1965
FIGURE 57. California gas production.
The oil fields in the San Joaquin and Los Angeles basins are the
largest producers of wet gas, with lesser amounts from the Ventura,
Salinas-Cuyama, and Santa Maria basins. About 80 percent of the
dry gas produced in 1964 came from fields in northern California (fig.
56), and nearly all these fields are in the Sacramento basin. Lesser
amounts were produced in the offshore part of the Ventura basin (13
percent), the San Joaquin basin (6 percent), the Eel basin (1 per-
cent) , and a few other minor areas.
Oil and Gas Provinces in California
There are eight principal productive sedimentary basins (figs. 47,
48) in the State which derive their names from the valleys or districts
in which they occur. The major oil-producing basins and their per-
centage of California's 1964 production are the San Joaquin (41), Los
Angeles (34), Ventura (15), Salinas-Cuyama (6.3), and Santa Maria
(3.4). The major dry-gas producing basin is the Sacramento which
yields about 80 percent of the State's production. The Sacramento,
Santa Cruz, and a few other small basins yield less than 1 percent of
the State's oil, and the Eel River basin yields less than 1 percent of
the dry gas. These eight basins, the outlines of which are slightly
modified from those shown by Vlissides and Quirin (1964), have an
area of about 31,000 square miles, about 19 percent of the area of the
State.
Los Angeles sedimentary hasin
The Los Angeles sedimentary basin (figs. 47, 48) extends along the
coast about 70 miles and inland as much as 40 miles. It has an area
312 MINERAL AND WATER RESOURCES OF CALIFORNIA
of about 1,450 square miles. This basin is the principal part of a more
extensive structural depression which extends westward an uncertain
distance beneath the ocean.
The most distinctive geologic characteristics of the basin is the large
concealed structural relief and the structural and stratigraphic com-
plexity (Yerkes and others, 1965). Three principal west-north-
westward-trending structural blocks are separated by the steep New-
port-Inglewood and Whittier fault zones. The former probably
separates genetically distinct groups of basement rocks on which the
sedimentary rocks were deposited.
Deformation, chiefly that beginning in Miocene time and culminat-
ing in mid-Pleistocene time, formed anticlines and faults in the sedi-
mentary rocks. These generally trend northwestward except in the
northern part of the area where the structural trend is more nearly
west. Deformation has continued to modern times as shown by earth-
quakes, warping of Recent rocks, and subsidence in some areas and
uplift in others. A nearly unique combination of geologic factors and
timing of events seems to account for the prolific oil production from
the basin (Barbat, 1958).
At least 31,000 feet of sedimentary rocks are present above the base-
ment floor in the deepest part of the central synclinal trough, about
10 miles southeast of the center of Los Angeles (McCulloh, 1960).
Edwards (1951) estimated that the volume of sedimentary rocks in
the basin is about 2,250 cubic miles, and Barbat (1958) estimated that
the volume of basinal sedimentary rocks within the drainage area of
the oil fields is some 1,600 cubic miles. Even if the foi-mer vohune is
used because it seems to be more comparable to estimates of the volume
in other basins, the recovery per cubic mile of sedimentary rocks al-
ready slightly exceeds the phenomenal amount of 2.33 million barrels.
Most of the known fields are structural accumulations on anticlines
or in fault traps, although some production of minor importance is
obtained from stratigraphic traps. The more important fields occur
along seven general productive trends which follow structural trends.
The most publicly noticed fields are those that lie on anticlinal struc-
tures along the Newport -Inglewood fault zone — Huntington Beach,
Seal Beach, Long Beach, Domiquez, Inglewood, and Cheviot Hills.
Most of the oil has been obtained from sands and conglomerates.
More than one-half has come from the Repetto (?) Formation of early
Pliocene age, and slightly less than one-half from rocks of late Miocene
age (fig. 49). Relatively minor amounts are obtained from rocks of
late Pliocene, middle Miocene, and pre-middle Miocene ages.
Surface evidence — seepages, geology, and topography — supple-
mented by subsurface studies led to the discovery^ of most of the fields
in the basin prior to 1936. In that year, the prolific production in the
Wilmington field was discovered as a result of seismic work. Since
1953, advanced geological exploration techniques, core-hole drilling,
and sparse seismic work have resulted in the discovery of seven new
fields and several new pools in known fields.
The Los Angeles sedimentary basin has been intensively explored.
If the deep central part of the basin, where very few deep wells have
been drilled is excluded, the density of exploratory wells is over 11 per
square mile.
MINERAL AND WATER RESOURCES OF CALIFORNIA 313
Some 56 fields (fig. 55) in the basin have produced 5.33 billion
barrels of oil to January 1, 1965 from 47,500 acres, or a recover}^ of
about 112,000 barrels per acre. Long Beach, an outstanding field, has
produced 843 million barrels from only 1,695 acres, or a recovery of
500,000 barrels per acre. Several deA'elopments in recent years have
greatly increased the production and reserves in the basin :
1. The removal of restrictions which prohibited drilling within the
cities of Los Angeles and Long Beach has resulted in intensified ex-
ploration and in the discovery of several new fields and new pools in
known fields in Los Angeles, and in the leasing of the huge East Wil-
mington field at Long Beach. New fields and new pools in Los Angeles
were producing more than 20,000 barrels of oil and 70 million cubic
feet of gas daily in early 1965, and it is estimated that some 100 to 150
million barrels of oil has been found since 1953. Also, it is estimated
that production from the largely offshore East Wilmington field will
be from 150 to 200 tliousand barrels daily by 1968, and that the field
will eventually yield 1.2 to 1.5 billion barrels.
2. Water is being injected into the oil reservoirs in several fields,
especially in tlie Wilmington field where about 565,000 barrels of water
is injected daily. The injection in the Wilmington field has nearly
stopped subsidence of tlie land surface which had reached a maximum
of about 27 feet, and is believed to have increased the daily oil produc-
tion approximately 53,000 barrels. The field now produces about
95,000 barrels per day, and it has been estimated that it would have
declined to 42,000 barrels per day without water injection. The esti-
mate of recoverable oil from the field has been increased about 400
million barrels, of which some 218 million barrels is expected to come
from the tidelands area of the field.
Striking features of the production in this basin are: (a) prolific
production from the relatively small sedimentary basin, and the small
areal extent of some of the prolific fields; (b) the thick oil zones — a
zone includes several sands separated by thin beds of shale; (c) the
fact that the vertical thickness (oil columns) of the oil zones often
greatly exceeds the "closure"' of the anticline — Long Beach, for ex-
ample, has 2,200 feet of oil sand in six oil zones with a total thickness
of 5,200 feet, although the estimated "closure" is only 1,600 feet; (d)
subsidence of the surface along the ocean front in the Wilmington
field; (e) subsurface damage to several hundred wells at Wilmington
as the result of earth movements notably from 1947-1951. The move-
ment in 1951 occurred at the time of an earthquake with an intensity
of V on the Modified Mercalli Intensity scale; (f) oil wells in citrus
and avocado groves and in business and high-class residential districts,
often requiring development by directional drilling from sound-
proofed derricks, and production from landscaped "islands"; (g) the
close spacing of wells in areas of town-lot drilling; (h) the rows of
pumping units a few feet apart along the ocean front, notably at
Huntington Beach. Wells drilled from these surface locations were
directionally drilled to properly spaced locations beneath the ocean;
(i) the drilling and production platforms and islands a few miles off-
shore and the large refineries close to the oil fields and the ocean.
Ventura sedimentafry basin
The Ventura sedimentary basin (figs. 47, 48) is an elongated east-
ward-trending basin at least 130 miles long and 20 to 40 miles wide
67-164 a— 66e- pt. I 21
314 MINERAL AND WATER RESOURCES OF CALIFORNIA
with an area of about 3,600 square miles. About 1,500 square miles of
the eastern part of the basin, including the Soledad subbasin at the
east end and a strip along the northwestern part of the basin, is on
land ; the rest of the western part is submerged beneath as much as
2,000 feet of water.
Structurally, the basin is a regional syncline on which numerous
eastward-trending folds have been superimposed, and which is broken
by numerous large thrusts and reverse faults. Some faults dip south-
ward, others north^vard. The central part of tlie basin lias been sub-
jected to north-south compression with the result that most of the
structural features trend westward in contrast to the northwestward
structural trend in most of the other oil regions of the State. Many of
the principal valleys retlect their synclinal structure, and many of the
hills or mountains reflects their anticlinal structure.
Sedimentary rocks about 58,000 feet thick were deposited in the
basin and rest on a granitic and schist basement. Included in the
sedimentary rocks are 13,000 to 15,000 feet of marine Pliocene rocks
in the vicinity of Ventura, perhaps the greatest thickness of these rocks
in the world. Eand (1951) estimated that some 17,000 cubic miles
of sedimentary and volcanic rocks are present in the basin. If it be
assumed that about 40 percent of this volume is on the land part of
the basin from which production to January 1, 1965 has been about
1.4 billion barrels, then about 206,000 barrels have been produced
per cubic mile of sedimentary rocks in that part of the basin.
Production is obtained from rocks of several different ages (fig.
49), but most of the oil comes from Pliocene and Miocene marine
sands and from nonmarine sands of Oligocene age. Lesser amounts
are produced from Cretaceous, Pal eocene. Eocene, and Pleistocene
sands, and from fractured rocks of Miocene age.
Most of the 78 fields in the basin (fig. 55) are structural accumula-
tions on faulted anticlines, but accumulations in fault or stratigraphic
traps are common. In recent years, prospecting along thrusts and
reverse faults has resulted in the discovery of several concealed anti-
clinal and fault accumulations beneath these faults.
The outstanding field in the basin is the Ventura field, wdiich has
produced 694 million barrels to January 1, 1965. It is 7 miles long
and about 1 mile wide, and is on the structurally highest part of the
16-mile-long, severely faulted, Ventura anticline. The recovery from
the 3,470 productive acres has been about 200,000 barrels per acre.
Gas from shallow wells in the field was supplied to Ventura as early
as 1903.
Striking features of the production in this basin are: (a) thick
Pliocene reservoirs in the Ventura field where there is a maximum of
about 7,500 feet of oil-bearing Pliocene strata, excluding repetition
by faulting; (b) the location of several fields in the rugged moun-
tainous regions overlooking the Santa Clara River valley; (c) ac-
cumulation of oil in the colorful nonmarine red beds of the Sespe
Formation of late Eocene to early Miocene age; (d) higher-than-
normal pressures in the Ventura field, especially in the deeper zones
where pressures at a depth of 9,200 feet were 8,300 pounds per square
inch, or about double that due to a column of water extending to the
surface; and (e) the development of moderate production in one
MINERAL AND WATER RESOURCES OF CALIFORNIA 315
fe
field in the basin by the unusual methods, for California, of drilling
with air and artificial fracturing of the reservoir rocks in order to in
crease the permeability.
San Joaquin sedimentary basin
Two large productive sedimentary basins — the San Joaquin and the
Sacramento — occur in the Great Valley (figs. 47, 48) and include the
valleys of those names and parts of the adjoining foothills. The
Stockton arch separates these two basins about 60 miles east of San
Francisco, and structurally unites the Diablo uplift on the west with
the Sierra Nevada block on the east. On this broad arch. Cretaceous
rocks are only about 3,500 -feet beneath the surface.
The San Joaquin .sedimentary basin (figs. 47, 48) trends northwest-
ward for 250 miles with a width of 50 to 60 miles. It has an area of
about 11,350 square miles. The maximum thickness of the sedimentary
rocks in the basin exceeds 30,000 feet, and the volume of those rocks
has been estimated at about 31,000 cubic miles (Kilkenny, 1951). As
the 105 fields (fig. 55) in the basin liave produced 5.5 billion barrels
to January 1, 1965, the production has been about 180,000 barrels per
cubic mile of sedimentary rocks, but that amount would be much
larger, perhaps doubled, if only the volume of the rocks in the oil-
productive southern part of the basin Avere used.
Structurally, the basin is an asymmetric syncline, the axis of which
lies near the west side of the San Joaquin Valley. According to
Repenning (1960), tlie structural basin was formed by the westward
tilting of the Sierra block against the eastern flank of the Coast
Ranges. The basin floor slopes gently westward to its deepest part.
East of the syncline, tension faults and gentle folds predominate;
west of the syncline closer to tlie San Andreas fault, the strata are
more steeply tilted and are broken by faults many of which are reverse
faults resulting from compression.
The Bakersfield arcli trends southwestward across the valley near
the city of that name, and separates the San Joaquin basin into sub-
basins. North of tlie arch the structural trend is northwestward; to
the south the trend is more nearly westward. Near the southern bor-
der of the basin, southward-dipping faults along which the upper
block has moved northward and asymmetric folds such as Wheeler
Ridge, in which the north flank dips more steeply than the south flank,
suggest stresses from the south.
Prominent anticlines in tlie Diablo and Temblor Ranges west of the
San Joaquin Valley trend southeastward into the valley, and many
are marked by prominent topographic features such as Kettleman
Hills and Elk Hills on which large oil fields have been developed.
The oil fields are concentrated in the southern part of the basin
which contains a large thickness of organic shales of Tertiary age.
These shales contain abundant remains of very small (microscopic)
plants and animals. Several gas fields, and gas sands in oil fields,
occur in the southern part, of the basin, but only gas fields have been
found between Fresno and Stockton.
Oil has accumulated in many varieties of traps, but much is in
stratigraphic traps associated with some element of structure. How-
ever, there are many structural accumulations on anticlines, and fault
316 MINERAL AND WATER RESOURCES OF CALIFORNIA
traps are more important than in other California basins, especially
along the east side of the valley.
Commercial accumulations occur in both marine and nonmarine
rocks and are widely distributed through 10 to 15 thousand feet of
strata ranging in age from Cretaceous to Pleistocene (fig. 49) . Some
production on the east side of the valley is obtained from pre-Cre-
taceous schist where it is overlain by oil-bearing sediments. About
90 percent of the production has come from rocks of Miocene and
later age (Simonson, 1958) including a large amount from nonmarine
rocks.
The Miocene, Pliocene, and Pleistocene rocks thin from south to
north and become largely nonmarine in the north and east parts of
the basin. The greatest thickness of sedimentary rocks is near the
southern end where they are more than 6 miles thick. Cretaceous
rocks, on the other hand, thin southward from the Stockton arch and
are absent in the southern end of the valley.
Striking features of the production in this basin are: (a) the great
concentration of oil fields in the southern part of the valley; (b) the
low^ API gravity of much of the oil near the margins of the basin;
(c) the long-continued drilling of new wells in old fields; (d) the
continual discoveries of new fields and extensions of old fields in the
highly explored Rakersfield-Taft-Coalmga area in the southern part
of the valley; (e) the large number of steam-injection secondary re-
covery operations; and (f) the presence of Naval Petroleum Reserves
No. 1 (Elk Hills) and No. 2 (Buena Vista Hills). The former is
maintained as a billion-barrel reserve by the Navy, and only a relatively
small amount of oil is produced for protection of the reservoirs; the
latter is not maintained as a reserve, but is actively produced.
Sacramento sedimentary basin
The Sacramento sedimentai^ basin (figs. 47, 48) extends north-
northwestward from the Stockton arch for 200 miles and is about
50 miles wide, except at the southern end where it widens to 70 miles.
It also may be divided into sub-basins. Rocks ranging in age from
Late Jurassic to Pleistocene are present in this basin, but the Miocene
and Pliocene rocks which yield prolific production in the southern
part of the Great Valley are thin and nonmarine, and yield only
minor amounts of gas.
Sedimentary rocks cover an area of 11,350 square miles (Hobson,
1951), but in this report the area of the basin is considered to be
9,200 square miles. The sedimentary rocks probably have a maximum
thickness beneath the valley of more than 35,000 feet, and the volume
of Lower Cretaceous to Pliocene sedimentary rocks was estimated to
be 44,000 cubic miles by Hobson (1951). The fields (fig. 56) in the
basin have produced about 3.5 trillion cubic feet of gas to January 1,
1965, or some 80 million cubic feet of gas per cubic mile of sedimen-
tary rocks.
Nearly all the production from the basin has been dry gas, al-
though some condensate is produced from a few fields. Recently,
moderate oil production has been found in sands of Paleocene and Late
Cretaceous ages in one field and a small amount of oil has been pro-
duced from a sand of Late Creataceous age in another field. Gas is
MINERAL AND WATER RESOURCES OF CALIFORNIA 317
obtained mostly from sands of Eocene, Paleocene, and Late Cretaceous
ages, but some comes from younger Tertiary rocks (fig. 49).
Structurally, the basin is an asymmetric syncline the axis of which
is near the west side of the valley. The basement floor slopes gently
westward from the Sierra Nevada into the deepest parts of the basin.
Steeply dipping Jurassic and Cretaceous sedimentary rocks along the
west border are separated from older basement rocks farther west
by faulting.
Sutter (Marysville) Buttes, a unique feature in the sedimentary
basins of California, rises 2,000 feet above the lowlands in the central
part of the valley, and is an eroded volcanic plug. Magma rising
to the surface arched and tilted the adjoining Creataceous and Eocene
rocks. The first commercial gas discovery in the basin was made
in 1933 close to the igneous plug, and there are now many gas fields
north, south, and west of the Buttes. A second unique feature in
the basin is the presence in the subsurface of sediment-filled channels
or gorges of pre-existing streams. Gas is found in stratigraphic
traps in these gorges.
Striking features of the production in the Sacramento basin are:
(a) gas, rather than oil, production, perhaps because the source
material, or the environment in which the rocks were deposited,
differed from those in the oil-productive basins; (b) the large amount
of gas produced from Cretaceous sands in contrast to the small amount
of oil from rocks of that age in other California basins; (c) the much
greater distance between wells than in the oil-productive areas be-
cause gas travels farther and more freely through the reservoir
sands; (d) the accumulations near the igneous plug of Sutter Buttes;
and (e) the abnormally high reservoir pressures in many Cretaceous
sands.
Although many seeps of high API gravity oil on the west side of the
Sacramento Valley have long been known and some wells drilled near
these seeps yielded a few barrels of oil, it was not until 1960 that a
possible commercial amount of crude oil was found in one gas well.
Early in 1963, the second and most important discovery of oil in the
basin was made unexpectedly during the development of the Brent-
wood field where only gas had been found previously. Oil production
from these two fields to January 1, 1965, has been 1.6 million barrels,
nearly all from the Brentwood field.
Santa Maria sedimentary hasin
The Santa Maria sedimentary basin (figs. 47, 48) which includes
several sub-basins extends about 40 miles along the coast, as much as
25 miles inland, and an uncertain distance offshore. The area of the
onshore part is slightly less than 1,000 square miles. The maximum
thickness of Tertiary and Pleistocene rocks in the basin is believed to
be about 16,000 feet, and the onshore part of the basin possibly con-
tains some 1,100 cubic miles of unaltered sedimentary rocks above the
Jurassic basement (Hobson and Lupton, 1951) .
Production of oil from the basin to January 1, 1965, has been
approximately 500 million barrels, or a recovery of about 450,000
barrels per cubic mile of sedimentary rocks.
The major structural features have a general west -northwestward
trend, and the last period of deformation was so geologically recent
318 MINERAL AND WATER RESOURCES OF CALIFORNIA
that the topography generally reflects the structure of the rocks — the
major valleys are synclinal, and the hills are anticlinal. The Santa
Maria Valley is an asymetric syncline, the axis of which is close to, or
beneath, the anticlinal folds of the Casmalia and Solomon Hills which
border the valley on the south.
Production is obtained from the hard, brittle fractured cherts and
shales in the Miocene Monterey Shale, from fractured sandstones of
Miocene age, from fractured sandstones of the Jurassic Knoxville
Formation, and from several sands of Miocene and Pliocene ages.
Also, a few barrels of oil are produced from a sand that may be of
Oligocene age. In contrast to the production from sands and con-
glomerates in other regions in California, Regan and Hughes (1949)
estimated that 77 percent of the production from the basin prior to
1947 had come from fractured rocks, nearly all of Miocene age, and
that only 23 percent had come from sands. The percentage from sands
has probably increased since that time.
Most of the 16 fields -(fig. 55) in the basin are structural accumula-
tions on anticlines, but some are stratigraphic accumulations, for in-
stance, the Santa Maria Valley field. This field, w^iich was discovered
in 1934, was the first major stratigraphic trap accumulation discovered
in California after the search for that type of trap began in the State.
Oil accumulated in the Monterey Shale, which overlaps the basement
rocks and is truncated updip by younger rocks. The latter, in turn,
rest on the basement farther north. "Closure"' of 3,000 feet at the
top of the Miocene sequence distinguishes this field from any other
in California.
Striking features of the production in this basin are: (a) the gen-
erally low API gravity of the oil; (b) the location of several fields on
high hills overlooking the Santa Maria Valley; (c) the loss of drilling
fluid while penetrating the fractured reservoir rocks often being an
indication of high permeability and, usually, of large initial produc-
tion; and (d) the first large California gusher in the Orcutt field
in 1904 flowed 12,000 barrels per day for several months, and pro-
duced some 3 million barrels of oil during its flow^ing life.
Salinas -Cuyama sedimentary basin
The Salinas-Cuyama sedimentary basin (figs. 47, 48) is an elon-
gated northwestward-trending basin between the much-publicized San
Andreas fault zone on the northeast and the Nacimiento fault zone on
the southwest. This basin is approximately 160 miles long and as
much as 28 miles wide, and includes the Cuyama and Salinas Valleys
and some of the intervening mountainous areas. The area of the basin
is about 3,100 square miles, and it contains approximately 3,500 cubic
miles of Miocene and younger rocks (Schwade and others, 1958) . The
Tertiary rocks, or older sedimentary rocks which underlie those rocks
in places, rest on a granitic basement in a large region called Salinia
(by Reed (1933). The maximum thickness of sedimentary rocks in
the basin probably exceeds 15,000 feet, but the depth to the granitic
basement is much shallower in large parts of the basin. The 14 fields
in the basin have produced approximately 380 million barrels of oil
to January 1, 1965, or about 110,000 barrels per cubic mile of sedimen-
tary rocks of Miocene or younger age.
The three large fields (fig. 55) — San Ardo, South Cuyama, and
Russell Ranch — in the basin greatly overshadow the several minor
MINERAL AND WATER RESOURCES OF CALIFORNIA 319
fields. The first field is on a broad, fiat anticline overlying a basement
high; the latter two fields are accumulations on faulted anticlines.
Nearly all of the oil is in sand reservoirs.
Striking features are: (a) the many dry holes that were drilled
prior to the discoveries in the late 1940's; (b) the more than 350
exploratory tests drilled since the three major discoveries, finding only
a few relatively small fields; (c) the many closed structures that are
barren probably because they were formed in late geologic time after
migration of the oil; (d) the very large accumulation of low API
gravity oil in the San Ardo field — the only major field in the Salinas
Valley part of the basin ; and (e) the tilted water table underlying the
oil in the San Ardo field. .
Santa Cruz and Eel River sedimentary hasins
The Santa Cruz sedimentary basin (figs. 47, 48), which is along the
coast about 25 miles south of San Francisco, has an onshore area of
about 260 square miles. Small oil production is obtained at present
from two fields in tlie basin from rocks of Eocene and Miocene ages
(fig. 40). An old field which is not now producing yielded a few
thousand barrels of oil from Pliocene rocks.
The Eel River sedimentary basin (figs. 47, 48), which borders the
coast in the northwestern part of California, has an onshore area of
about 575 square miles. Two dry gas fields which yield gas from
Pliocene rocks (fig. 49) have been found in the basin. Eleven pro-
ducing wells in the Tompkins Hill field produced an average of about
5 million cubic feet of gas daily in 1964. Only a small amount of gas
has been produced from tlie Table Bluff field. No production has
been reported from a possible third gas field, Grizzly Bluff.
Offshore
Seaward from the coastline of California a submerged region of
more than 27,000 square miles is known as the continental shelf. The
continental shelf is usually defined as that part of the ocean lying be-
tAveen the low-water line and the sharp change in inclination of the
sea bottom that marks the beginning of the continental slope (the shelf
edge). Geologically, this abrupt change in inclination, rather than
the present shoreline, marks the true edge of the continents (Trum-
bull, 1958) . For convenience, the 100-fathom (600-foot) line is useful
for an approximation of the shelf edge in most regions. On plate 1
of this report the 500-foot contour line may be used as an
approximation.
North of Point Conception, the continental shelf off California is
comparatively narrow, generally less than 10 miles and sometimes less
than 1 mile wide. West of San Francisco, however, it widens to
about 30 miles.
South of Point Conception, the region between the mainland and
the continental slope is broad and extends as much as 160 miles sea-
ward. It is complex, with islands, flat-topped banks some of which
are only slightly submerged, and about 14 closed basins (closed depres-
sions deeper than the surrounding area). Because of this complexity
this region has been called the continental borderland by Shepard
and Emery (1941) to distinguish it from typical continental shelves
in most other areas of the world. Its area is more than 19,000 square
320 MINERAL AND WATER RESOURCES OF CALIFORNIA
miles, and it is covered by Avater Avitli an averaoe depth of about
3,500 feet and a maximum deptli in one locality of nearly 7,000 feet.
The 1958 Ignited Nations Conference on the Law of the Sea provides
that the sovereign rights of a nation to the subsoil off its coasts extend
to where the sea is 656 feet deep and, beyond that limit, as much
farther as it can exploit the resources of the undersea area.
Early in 1065, the Supreme Court of the United States decided that
the boundary of the State of California would be measured by a line 3
geographic (3.45 statute) miles from the low-tide line of the mainland
shore, and by lines a like distance around each island. As a conse-
quence, the State of California or its grantees owns the mineral re-
sources on slightly more than 5,000 square statute miles within the
3-mile limit, as measured on 1961-62 maps. This area will likely be
modified by the Supreme Court's decision which included Monterey
Bay in the State. The United States owns, or can exploit, the mineral
resources on the more than 22,000 square statute miles more than
3 miles from the mainland or the islands.
Public information concerning the geologic conditions offshore is
very limited, especially north of Point Conception. Inferences may be
made from geologic maps of the mainland and the islands. Perhaps
the most important inference concerning oil and gas is that five of the
onshore productive sedimentary basins (figs. 47. 48) doubtless extend
offshore. There are sparse published records on the ages of the rocks
from which oil production is now obtained offshore, and on the depths
of some of the exploratory wells. In addition, published reports by
Emery (1960), and by Bromery, Emery, and Balsley (1960) contain
considerable geological and geophysical information on the continental
borderland south of Point Conception, the best known area off the
California coast. The following brief descriptions is taken from these
reports.
Structurally, the borderland consists of many blocks of rouglily
equal size. Emery suggests that these blocks are crossed by seven
long primary faults most of which trend northwestward, and that
many shorter features which may be faults or folds trend more west-
ward between the primary faults. The anticlinal structure of some of
the islands and of the sea bottom in places is known or inferred. The
anticlinal structures on which several of the productive onshore oil
fields are located extend beneath the ocean, and production is also
obtained offshore on these features. Most of the fields off the coast
from near Santa Barbara to Point (Conception are on a westward
trend of faulted anticlines.
The area of the closed basins and other deep flat areas in the border-
land is about 9,000 square miles. Most of the basins are oriented
parallel to the structural trend of the Peninsular Ranges on land,
but the most northerly one which is believed to be the submerged
extension of the Ventura basin is oriented parallel to the Transverse
Ranges. These basins are closely related in form and probable origin
to the land basins. Both are probably controlled by the regional
structure.
The most widely distributed rocks on the sea floor in the border-
land are of Miocene age, but the ocean bottom in the basins is largely
covered with Pliocene and younger sedimentary rocks and micon-
MINERAL AND WATER RESOURCES OF CALIFORNIA 321
solidated sediments. It can be inferred that Miocene, and possibly
older sedimentary rocks, are also present at depth in some or all of
the basins. The present nearshore fields in the borderland produce
oil from rocks of Pliocene, Miocene, and Oligocene ages. Early
Tertiary and Cretaceous rocks crop out on some of the islands.
The thickness of sedimentary rocks in the borderland is believed
to be about 4,500 feet in one basin, and about 10,000 feet in another.
Tliicker sedimentary rocks are doubtless present in parts of the bor-
derland as the deepest offshore Avell, about three-fourths of a mile from
the coast southeast of Santa Barbara, was drilled to a depth of ap-
proximately 16,000 feet.
North of Point Conception, thick sedimentary rocks are obviously
present at places on the continental shelf but there is very little
public information about the geology of this region. Outside of the
3-mile line at least one exploratory well was drilled to a depth of
approximately 10,400 feet, and several other wells have been drilled
to depths of 7,000 to 8,000 feet. It can probably be assumed that
sedimentary rocks were penetrated for most of these depths. The
presence of thick sedimentary rocks west of the granitic Farallon
Islands off San Francisco has been inferred by Thompson and Talwani
(1964).
Very large amounts of money have been spent by the oil industry
in exploring for and developing oil and gas off the coast. Baldwm
(1965) estimated that approximately $310 million was spent from 1949
to early 1965 off the Pacific Coast for exploration, for acquiring leases,
and for platforms prior to the drilling of development wells. Prob-
ably about $270 million of this has been spent off California including
$172 million for; State leases, $12.8 million for Federal leases, $25
million for seismic geophysical lines, $35 million for the drilling and
coring of some 2,650 holes, and $25 million for platforms and islands.
The industry has also spent very large amounts of money for drilling
development wells that produce oil from beneath the ocean, and for
other costs incident to producing operations.
History of discovery and development offshore
The old Summerland field in the Ventura basin was the first field in
California in which oil was produced from beneath the ocean. The
field was discovered onshore prior to 1894, and in 1896 the first shallow
wells beneath the water were drilled from wharfs, some of which
extended a quarter of a mile from shore. A 1902 map shows 187
productive offshore wells, and others may have been drilled later.
The wharfs and wells have been destroyed by storms or torn down.
About one-third million barrels of oil were produced offshore.
Since 1929, many oil and gas leases for submerged lands within the
3-mile limit have been issued by the State or its grantees. From 1927-
1956, eight oil fields (fig. 55) in the Los Angeles and Ventura basins
were extended beneath the ocean by directional drilling from land.
The first discovery of a new field beneath the ocean, which at the
time did not seem to be connected with an onshore field, was made in
1948 at the Belmont offshore field in the Los Angeles sedimentary
basin (fig. 55). Further development of the field did not start until
1954, when a man-made island was constructed 8,300 feet from shore.
322 MINERAL AND WATER RESOURCES OF CALIFORNIA
Six additional producing oil fields and four producing dry gas fields
have been discovered oiTshore in recent years.
Leases on 516 square miles of Federal submerged land outside of the
3-mile limit north of Point Conception were issued in 1963. Several
exploratory wells, some of which were in about 600 feet of water, have
been drilled on these lands recently, but no discoveries were reported
to August 1965. No leases have been issued on Federal submerged
lands south of Point Conception, but exploratory w^ells as deep as
8,000 feet were drilled on these lands prior to 1965.
Cumulative production to Januaiy 1, 1965, from about 2,000 off-
shore wells was 778.1 million barrels of oil, 79 billion cubic feet of dry
gas, and more than 57 billion cubic feet of wet gas. Statistics for wet
gas are incomplete. The value of this oil, using the current average
price of $2.4:7 per barrel, was about $1.75 billion.
The eight oil fields that are extensions of onshore fields have pro-
duced 95 percent of the offshore oil, mostly from the submerged parts
of the Wilmington and Huntington Beach fields (fig. 55) in the Los
Angeles sedimentary basin. The seven oil fields that have been dis-
covered offshore are more recent fields. They have produced 38 million
barrels, or only 5 percent of the total.
In 1964, the offshore fields produced 40.5 millions barrels (fig. 58)
at an average daily rate of 110,700 barrels, or slightly more than
one-eighth of California's production. Offshore oil and gas production
has increased rapidly in recent years (figs. 58, 59). Three of the off-
shore fields are small, and each yielded less than 100 barrels per day
in 1964. The production of dry gas in 1964, all of it in the submerged
part of the Ventura sedimentary basin, was 35.6 billion cubic feet
(fig. 59) , or about 100 million cubic feet daily.
On January 1, 1965, oil and gas were being produced in 14 offshore
oil fields and 4 offshore diy gas fields. One of the 14 oil fields now
yields only a small amount of oil, but produces a moderate amount of
dry gas. A small amount of oil was obtained prior to 1959 from the
offshore part of one additional field. All these fields are in the sub-
merged extensions of the Los Angeles and Ventura sedimentary basins.
All are on submerged lands leased from the State or its grantees.
Resources
The oil and gas resources of California may be divided into proved
reserves and potential resources.
Proved reserves
Proved reserves are defined by the American Petroleum Institute as
"the amount of oil in knoion petroleum deposits recoverable under ex-
isting economic and operating conditions,"' or as sometimes stated by
others, the recoverable reserves whose location and extent have been
proved and measured by drilling.
Generally, the published estimates of reser^^es as so defined are
probably on the conservative side. Among the reasons for this are:
1. Revisions and additions to reserves are commonly made for new'
fields as they are developed, and it is seldom that the amount of re-
coverable oil in a new field can be quantitatively estimated with rea-
MINERAL AND WATER RESOURCES OF CALIFORNIA
323
Of f shore Los Ange les
sedimentary basin
6 fields in 1 964
-^••'Offshore Ventura sedimentary basin/
■ 8 f ie Ids in l 964 /•
1935 1940 1945 1950 1955 1960 1964
FiGUBE 58. California offshore oil production.
>10
-J
<
i 9
z
<
«, 8
UJ
S 7
<
m
§ 6
d 5
^ 4
o ^
^ 3
a
o
o 1
8 f ie Ids
in 1964
Sources :Conse rva t i on Committee of
Ca li f orn ia oil producers
5 fields
in 1964
^ ■
<^'^
40
30
20
— z
H Z
O <
O UJ
</) CD
io5S
tr —
0 ° :^
1928 1930
1935
1940
1945
1950
1955
1960
1965 <^
Figure .59. Offshore oil and dry gas production in Ventura sedimentary basin,
California.
324 MINERAL AND WATER RESOURCES OF CALIFORNIA
sonable accuracy early in the life of the field. Several new fields in
California are now in the early stages of development.
2. Secondary recovery methods, some of which verge on well-stimu-
lation methods, are being applied in more than 300 pools in some
100 fields in the State. Because of the recency of the use of some of
the thennal methods which are reported to have increased pixjduc-
tion about 30,000 barrels per day, it is impossible to estimate how
much additional oil may be recovered. It is quite certain, however,
that additions of this kind are not included with the statistics on
proved reserves in most inst-ances. Although it was estimated in
1962 that about 29 percent of the oil found in the United States to
that time would be recovered b}^ primary methods, it is believed that
the primaiy recovery in California Avill on the average be somewhat
less than 25 percent. In many California fields which produce viscous
heavy (under 20° API gravity) oil, it is believed that the recovery
by primary methods may be only about 10 percent. It is quite cer-
tain that secondary' recoveiy methods will considerably increase the
recovery from California fields. Statements have been made by repre-
sentatives of the oil industry that the use of secondary recovery meth-
ods will increase California reserves by more than 1 billion barrels.
3. Xew techniques of Avell logging, testing, and completion some-
times result in increased reserves in existing fields.
4. The large East Wilmington field, partly onshore but mostly off-
shore, is estimated to contain at least 1.2 billion barrels of recover-
able oil. The field is known and has been approximately outlined,
but development was not begun until the middle of 1965. Published
reserves include 500 million barrels for this field.
The proved reserves of crude oil in the United States as of Jan-
uary 1, 1965, have been variously estimated at 35.1 billion barrels
b}^ the Oil and Gas Journal and at 31 billion barrels by the Amer-
ican Petroleum Institute. The proved resen-es of crude oil in Cali-
fornia are estimated at -1.1 billion barrels (fig. 60, table 35), about
1-t times the 1964 production, or 13.3 percent of the United States
reserves according to the American Petroleum Institute.
The estimated proved resen'es of crude oil in California declined
from a high of 3.9 billion barels on January 1, 1954, to 3.6 billion
barrels on January' 1, 1964. This declining trend was reversed in
1964 when reserves increased 526 million barrels to 4.1 billion bar-
rels, the largest ever estimated, due largely to the assignment of 500
million barrels to the East Wilmington field.
Several features of these reserves of crude oil are of imiwrtance.
1. Although the proved reserves of California are 14 times the
annual production, a much longer period than 14 years will be required
to bring the oil to the surface. Several fields more than 50 years old
are still producing large amounts of oil.
2. Xearly all the proved reserves are in five sedimentary' basins in
the southwestern part of the State, mainly in the San Joaquin basin
(2.2 billion barrels) and the Los Angeles basin (1.25 billion barrels).
3. More than 80 percent of the proved reserves in California are in
the "giant" fields — those which are expected to yield more than 100
million barrels of oil. There are 40 of these fields in California, at
present, the last one having been discovered in 1949. However, recent
MINERAL AND WATER RESOURCES OF CALIFORNIA 325
'^14-
u
u
o
<
-J
<
q:
••• Natura I gas ..•*
Crude oil
Sources: Gas, Calif. Div. Oil and
Gas; Crude oil, Calif. Div. Mines
and Geology Bui 1 . 118. 1 926-40
American Petroleum Institute 1941-63
I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I
a:
q:
5 «
b.
O
4 ^
o
3 -
to
I.
a:
u
^ 1926 1930 1935 1940 1945 1950 1955 1960 1965
<
z
Figure 60. Estimated proved reserves of crude oil and natural gas in California,
on January 1 of each year.
discoveries near Los Angeles and McKittrick may approach the
"giant" class, if initially isolated discoveries prove to be single fields.
4. The two fields with the largest proved reserves are Elk Hills in
the San Joaquin basin fiT)m which only a small amoimt of oil is pro-
duced at present because it is in Naval Petroleum Reserve No. 1, and
the Wilmington field in the Los Angeles basin. To these might be
added the largest known, but undeveloped, reserve of at least 1.2 bil-
lion barrels in the East Wilmington field.
Tlie proved reserves of natural-gas liquids in California on January
1, 1965, were estimated at 270.8 million barrels (table 35).
Tlie estimated proved reserves of natural gas in the United States on
January 1, 1965, were 290 trillion cubic feet according to the Oil and
Gas Journal. The reserves in California (fig. 60) on that date were
10.2 trillion cubic feet according to estimates by the California Divi-
sion of Oil and Gas, or about 15 times the annual net withdrawals (pro-
duction less amount reinjected). The reserves in the State have in-
creased about 1.5 trillion cubic feet since the middle 1950's.
Approximately 60 percent of the gas reserves in California are wet,
or oil-well gas. The largest reserves of wet gas are in the San Joaquin
sedimentary basin, followed by the Los Angeles and Ventura basins.
By far the largest resen^es of dry gas are in the Sacramento basin,
followed by the Ventura and San Joaquin basins.
Potential resources
Onshore. — Conjectures concerning the potential resources onshore
in California suggest that they are large. It is generally believed that
the most favorable localities for new discoveries are in areas of proved
oil generation within the principal productive sedimentary basins
( figs. 47, 48 ) . Also favorable are some smaller sedimentary basins and
other areas underlain by sedimentary rocks; minor amounts of oil and
gas have been produced in several localities outside of the principal
basins, especially in the California Coast Ranges.
The complex geologic structure and statigraphy in California forms
innumerable traps in which oil and gas may have accumulated. Prac-
tically all the obvious traps in the principal basins were tested by the
326 MINERAL AND WATER RESOURCES OF CALIFORNIA
drill long ago, but very many obscure traps have been found in the
past and certainly many more exist. Obscure traps are very difficult
to find, but the discoveries in recent years show that they can be found
in the already highly explored areas of California by creative think-
ing in exploration. With some exceptions, for example in the Salinas-
Cuyama sedimentary basin, it may be said that any trap in the princi-
pal productive basins has a good chance of yielding oil or gas.
Parts of the principal productive basins are relatively untested.
Many additional concealed stratigraphic traps may be present, espe-
cially on the flanks of known anticlinal structures and on the deeply
buried flanks of the deepest parts of the basins. Not all of the known
structural traps have been completely tested by drilling through all
possible reservior rocks at adequately spaced locations. The area
of the principal productive sedimentary basins is about 20 million
acres, of which about 475,000 acres have yielded oil or gas. Approxi-
mately 5.5 million acres of unproductive land in the State are under
lease for oil and gas; a large part of this leased land is within the
principal productive basins.
The 13.25 billion barrels of oil already produced in California plus
the 4.1 billion barrels of proved reserves of recoverable oil totals 17.4
billion barrels. If it is assumed that this is 25 percent of the oil
originally in place, about 52 billion barrels of oil will not be recovered
by the primary methods of production. Some of this remaining oil
is being recovered now by the use of secondary recovery methods.
The Interstate Oil Compact Commission and several individuals
(Supplies, costs, and uses of the fossil fuels. Energy Policy Staff,
U.S. Department of the Interior, 1962) have made some estimates of
the petroleum resources of California in addition to the proved re-
serves of 4.5 billion barrels. These estimates include (a) 1 billion
barrels of oil that can be expected to be recovered by established sec-
ondary recovery operations, (b) 4.1 billion barrels that may be re-
covered as a result of changed economic conditions or improved tech-
nology, and (c) 1.3 billion barrels that could be recovered from known
reserves of presently nonfluid oil in bituminous rocks or shale at a
cost that is not now competitive with oil from wells.
In eastern California, the Salton Trough, the Mojave Desert, the
Great Basin, and the Modoc Plateau provinces (fig. 47) do not yield
oil at present, and except in the Salton Trough, few wells have been
drilled. Only one surface evidence of oil seems to be a verified seep,
but petroliferous rocks are known in Nevada to the east, and oil seeps
have been reported south of the border in Mexico. The southeastern
part of the Great Basin province in California contains thick Paleo-
zoic and Mesozoic marine sedimentary rocks which may be worth
testing for oil and gas.
Onlv a few very small showinas of o-as have been found in some 20
exploratory wells in the major sedimentary basm m the Imperial
Valley region of the Salton Trough province. Marine sedimentary
rocks that crop out in the hills west of the valley have not been found
to depths of more than 12,000 feet in the central part of the valley,
but may be present at even greater depths.
Offsiiore. — The potential resources of oil and gas off the coast of
California, not only within the boundaries of the State but also on
Federal lands outside the 3-mile line, are believed to be large. More
MINERAL AND WATER RESOURCES OF CALIFORNIA 327
than 6 years ago, it was estimated that fields on the mainland within
8 miles of the coast would ultimately jdeld about 3.9 billion barrels
of oil. Also, it was suggested that, if the offshore geologic province
is similar to the onshore province, a like amount might ultimately be
obtained from the offshore area inside the .3-mile line within the
boundaries of California. It was pointed out that 50 percent of the
prolific Los Angeles and Ventura sedimentary basins are believed to
lie offshore, and that the Santa Maria basin extends offshore. The
Santa Cruz and Eel River basins also probably extend offshore (figs.
47,48).
The amount of oil estimated to be recovered from the onshore fields
can probably be increased tDjii)proximately 4.2 billion barrels largely
because of the increased estimates for the "Wilmington field. Nearly
0.8 billion barrels of oil has been produced offshore to 1965, so accord-
ing to these estimates some 3.4 billion barrels may be produced off-
shore from within the 3-mile line in the future. Probably 1.5 billion
barrels of that amount can be expected from presently known fields,
including East Wilmington. The remaining 1.9 billion barrels may
represent an allowable amount for the potential offshore resources of
other areas inside the 3-mile line within the State's boundaries on
the basis of the foregoing estimates.
Selected References
Bailey, T. L., and Jahns. R. H.. 1954, Geology of the Transverse Range province,
southern California [Pt.] 6 in Chap. 2 of Jahns, R. H., ed.. Geology of southern
California : California Div. Mines Bull. 170, p. 83-106.
Baldwin, T. A., 196.J, Pacific offshore exploration 1949--196.5: Am. Assoc. Petro-
leum Geologists, Soc. Econ. Geologists, and Soc. Econ. Paleontologists and
Mineralogists, Pacific Sec, 40th .Joint Ann. Metg., Bakersfield, California,
April 1-2, 196.J.
Barbat, W. F., 1958, The Los Angeles Basin area, California, in Habitat of oil, a
symix)Sium : Tulsa, Okla., Am. Assoc. Petroleum Geologists, p. 62-77.
Bauer, R. M.. and Dodge, J. F.. 1943, Natural gas fields of California : California
Div. Mines Bull. 118. pt. 1, p. 33-36.
Bowen, O. E., .Jr., ed., and others, 1962, Geologic guide to the gas and oil fields of
northern California : California Div. Mines and Geology Bull. 181, 412 p.
Bromery, R. W., Emery, K. O.. and Balsley, J. R., Jr., 1960, Reconnaissance air-
borne magnetometer survey off southern California : U.S. Geol. Survey Geophys.
Inv. Map GP-211.
Edwards, E. C, 1951, Los Angeles region : Am. Assoc. Petroleum Geologists Bull.,
v. 35, no. 2, p. 241-248.
Emery, K. O., 1960, The sea off southern California — a modern habitat of
I>etroleum : New York, John Wiley and Sons, 306 p.
Hart, E. W.. 1957, Natural gas, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 373-384.
Hedberg, H. D., 1964, Geologic aspects of the origin of petroleum : Am. Assoc.
Petroleum Geologists Bull., v. 48, no. 11, p. 1,75.5-1,803.
Heizer, R. F., 1943, Aboriginal use of bitumen by the California Indians : Cali-
fornia Div. Mines Bull. 118, pt. 1, chap. 3, p. 74.
Hobson, H. D., 1951, Sacramento Valley : Am. Assoc. Petroleum Geologists Bull.,
V. 35, no. 2, p. 209-214.
Hobson, H. D., and Lupton, B. C, 1951. Santa Maria province: Am. Assoc. Pe-
troleum Geologists Bull., v. 35. no. 2, p. 224-230.
Hoots, H. W., 1943, Origin, migration, and accumulation of oil in California :
California Div. Mines Bull. 118, pt. 2. chap. 7, p. 2.52-276.
Hoots, H. W., and Bear, T. L., 1954, History of oil exploration and discovery in
California, [Pt.] 1. in chap. 9 of Jahns, R. H., ed.. Geology of southern Cali-
fornia : California Div. Mines Bull. 170, p. 5-9.
Hoots, H. W., Bear, T. L,.. and Kleinpell, W. D., 19.54, Geological summary of the
San Joaquin Valley, California, [Pt.] 8, in chap. 2, of Jahns, R. H., ed.. Geology
of southern California : California Div. Mines Bull. 170, p. 113-129.
328 MINERAL AND WATER RESOURCES OF CALIFORNIA
Jahns, R. H., 1954, Geology of the Peninsular Range province, southern California
and Baja California [Mexico], [Pt.] 3, in Chap. 2 of Jahns, R. H., ed. Geology
of southern California : California Div. Mines Bull. 170, p. 29-52.
Jennings, C. W., 1957, Petroleum, in Mineral commodities of California : Cali-
fornia Uiv. Mines Bull. 176, p. 409-424.
Kilkenny, J. E., 1951, San Joaquin Valley : Am. Assoc. Petroleum Geologists Bull.
35, no. 2, p. 215-218.
Levorsen, A. I., 1954, Geology of i>etroleum : San Francisco, W. H. Freeman and
Co., 703 p.
McCuUoh, T. H., 1957, Simple Bouguer gravity and generalized geologic map
of the northwestern part of the Los Angeles Basin, California : U.S. Geol.
Survey Geophys. Inv. Map GP-149.
, 1960, Gravity variations and the geology of the Los Angeles Basin of
California : U.S. Geol. Survey Prof. Paper 400-B, p. 320-328.
Rand, W. W., 1951, Ventura Basin : Am. Assoc. Petroleum Geologists Bull., v.
35, no. 2, p. 231-240.
Reed, R. D., 1933, Geology of California : Tulsa, Okla., Am Assoc. Petroleum
Geologists, 355 p.
Regan, L. J., and Hughes, A. W., 1949, Fractured reservoirs of Santa Maria
district, California : Am. Assoc. Petroleum Geologists Bull., v. 33, no. 1, p.
32-51.
Repenning, C. A., 1960, Geological summary of the Central Valley of California,
with reference to the disposal of liquid waste : U.S. Geol. Survey open-file
report.
Schwade, I. T., 1958, Geologic environment of Cuyama Valley oil fields, California,
in Habitat of oil, a symposium : Tulsa. Okla., Am. Assoc. Petroleum Geologists,
p. 78-98.
Shepard, F. P., and Emery, K. O., 1941, Submarine topography off the California
coast — canyons and tectonic interpretation : Geol. Soc. America Spec. Paper
31, 171 p.
Simonson, R. R., 1958, Oil in the San Joaquin Valley, California, in Habitat of
oil — a symposium : Tulsa, Okla.. Am. Assoc. Petroleum Geologists, p. 99-112.
Thompson, G. A., and Talwani, Manik. 1964, Geology of the crust and mantle,
western United States : Science, v. 146, no. 3,651, p. 1,539^1,549.
Trumbull, James, 1958, Continents and ocean basins and their relation to conti-
nental shelves and continental slopes, [Pt.] 1, of An introduction to the geology
and mineral resources of the continental shelves of the Americas : U.S. Geol.
Survey Bull. 1,067, p. 1-26.
U.S. Dept. Interior, Energy policy staff, 1963, Supplies, costs, and uses of the
fossil fuels : U.S. Dept. Interior. 34 p., tables.
Vernon, J. W., and Slater, R. A., 196:3. Submarine tar mounds, Santa Barbara
County. California : Am. Assoc. Petroleum Geologists Bull., v. 47. no. 8. p.
1,62^1,627.
Vlissides, S. D., and Quirin, B. A.. 1964. Oil and gas fields of the United States :
U.S. Geol. Sun-ey, map.
Weeks. L. G.. 1958, Habitat of oil and some factors that control it, in Habitat of
oil, a symposium : Tulsa. Okla., Am. Assoc. Petroleum Geologists, p. 1-61.
Woodford, A. O., Schoellhamer. J. E.. Vedder. J. G.. and Yerkes, R. F.. [Pt.] 5. in
chap. 2 of Jahns, R. H.. ed.. Geology of southern California : California Div.
Mines Bull. 170, p. 65-81.
Woodring, W. P.. and Bramlette, ^NI. N., 1950. Geology and paleontology of the
Santa Maria district. California : U.S. Geol. Survey Prof. Paper 222. 185, p.,
alius.
Yerkes, R. F., McCulloh, T. H., Schoellhamer, J. E., and Vedder, J. G., 1965
Geology of the Los Angeles basin : U.S. Geol. Survey Prof. Paper 420-A, 57 p.
PHOSPHATE
(By H. D. Gower. U.S. Geological Survey, Menlo Park. Calif.)
Phosphate rock is the principal industrial source of phosphorous, an
element essential in sustaining all life. Plants extract phosphorous
from the soil, and animals in turn obtain phosphorous by consuming
plants. Extensively farmed soil soon becomes depleted and unproduc-
MINERAL AXU WATER RESOURCES OF CALIFORNIA 329
five iinloss addit ional phosplioroiis is added. Man has used pliosphatic
material for fertilizer for iikhv than '2,000 years, hut it was not until
the middle of the 19th century that he learned to produce fertilizers
from phosphate rock, l^efore then bones, fish, and guano Avere the
main sources of phosj)liate fertilizer. Today most phosphate ferti-
lizers are nuule from phosphate rock. About 70 percent of the world's
production of phosphate rock is used for the production of fertilizer.
Phos[)horous has many other uses in industry. A few of the more
important uses are in tlie nuuiufacture of deterg-ents and soaps, animal
feed supi^lements, baking powders, metallurgical alloys, water soften-
ing agents, petroleum refining agents and additives, drugs, and mili-
tary devices (including incendiaiy bombs and smoke screens).
In 196;> the world production of phosphate rock was slightly over 50
million tons (Lewis, 1904). The I'nited States accounted for 39 per-
cent of the world's total production. Florida produced 74 percent of
the United States total, followed by the Western States (Idaho, Mon-
tana, Utah, and "Wyoming) with 14 percent, and Tennessee and Arkan-
sas with 1'2 perceiu. Sixty percent of United States production in
1963 was used in agriculture, 19 percent in the chemical industry, and
21 percent was exported (most of this was also used in agriculture)
(I^wis, 1964). No phosphate rock has been produced in California.
Phosphate is i)i'ecipitated under certain marine environments and
nearly all of the woi-ld's important deposits of phosphate rock occur
in rocks of marine origin. Several times during the Miocene Epoch
conditions were such that phosphate was i)recij)itated over much of the
southwestern part of Ualifornia. Although phosphate rock was
deposited over a wide area oidy in certain places were conditions
suitable for the accumulation of concentrations of phosphate of
sufficient amounts to l)e of j^otential economic value. After the plios-
phatic strata were formed they were buried and compacted imder thick
accumulations of younger sediments and later deformed by folding
and faulting. Subseciuent erosion removed the pliosphatic strata from
many areas, and only i)art of the original pliosphatic strata remains.
The principal phosphate mineral of marine phosphate rocks is a
variety of apatite called carbonate-fluorapatite. In California it
occurs as light-gray to dark-brown pellets (0.1 to 2.0 mm in diameter),
nodules (more than 2 mm in diameter), and laminae of very finely
divided i)hosphate. Most California phosphate rock is thin bedded
and closely associated with siliceous shale and bentonite.
Phosphate content is usually expressed as percent phosphorous
pentoxide (PoO,-,) or less commonly as percent BPL (bone phosphate
of lime) which is tricalcium phosphate, Ca.j(P04)2. One percent
P-Or, equals 2.18 percent BPL. In the western phosphate field high-
grade rock must contain a minimum of 31 percent P2O5, and low-grade
rock must contain at least 16 percent PsO.-, (Service and Popoff, 1964).
Very little is yet known about the California phosphate deposits, but
all of the known deposits appear to be below the minimum standards
for low-grade rock in the western phosphate field. However, close
proximity to markets and possible ease of beneficiation may allow
production from lower grade deposits in California. The only de-
tailed chemical analyses of pliosphatic sections in California that are
currently available are for one measured section in the central part of
67-164 0—66 — pt. I 22
330 MINERAL AND WATER RESOURCES OF CALIFORNIA
the Indian Creek deposit of San Luis Obispo County. At that local-
ity, about 50 feet of strata average nearly 4% percent P2O5 and the
main 21-foot-thick j^hosphatic section averages about 6i/^ percent
P2O5. The thickness and concentration of phosphate varies from
place to place and in other parts of the area the phosphate may be
greater or less than at the section analyzed.
Occurrences in California
The occurrence of phosphate in sedimentary rocks in California
has been known for several decades, but it was not until about 1960 that
its potential economic value was actively explored. By mid- 1965 four
deposits of potential economic value had been examined in consider-
able detail by commercial interests; these, as shown on figure 61, are the
Chico-Martinez Creek deposit of Kern County, the Indian Creek de-
posit of San Luis Obispo County, the Cuyama Valley Deposit of
Santa Barbara County, and the Pine Mountain deposit of Ventura
County. None of these deposits have yet been proven to be of com-
mercial grade, but exploration work is continuing on the latter three
deposits. There has also been some interest in the occurrence of
low-fluorine nonmarine phosphate near Hyampom in Trinity County.
Phosphate has been reported over a wide area of California (Gow^er
and Madsen, 1964) , but most of the occurrences are concentrated in the
southern Coast Ranges, western Transverse Ranges, and southwestern
Great Valley (fig. 61). Nearly all of these occurrences are in rocks
of Miocene age. Most occurrences shown on figure 61 are small and
of no economic importance. However, they are important in pointing
out areas for future prospecting, for the thickness and grade of phos-
phatic sections can vary greatly over a short distance. A slightly
phosphatic horizon in one area may grade laterally into a significant
phosphate deposit only 2 or 3 miles away.
Hyamj)oin 'prosfect
Low-fluorine nonmarine phosphate rock interbedded with siliceous
and tuffaceous shales of the Oligocene (?) Weaverville Formation
(Lydon, 1964) has been prospected by L. D. Cartwright near Hyam-
pom in Trinity County. Because of the low fluorine content, this
material could be readily used in animal feed supplements and in
lime and ammonium fertilizer. Veiy little exploration work hasl)een
done on this occurrence, but it is questionable that it contains enough
phosphatic rock to be of economic significance.
Indian Creek frospect
Phosphate rocks in the upper part of the Monterey Formation in
the Indian Creek area, about 10 miles east of Creston in San Luis
Obispo County, have been extensively prospected by Nicol Industrial
Mineral Corp. The prospect is still under study. The pliosphate
rocks occurs in thin pellet beds interbedded with siliceous shale and
bentonite. Phosphate occurs throughout about 70 feet of section, but
the main phosphatic zone is about 21 feet thick.
Ghico-Martmez Creek frospect
Pelletal phosphate rock in the lower part of the Temblor Forma-
tion in the vicinity Chico-Martinez Creek in Kern County was pros-
MINERAL AND WATER RESOURCES OF CALIFORNIA
331
v.
m
TRINITY
/
123' 122' 12r 120-
^ s I s K ij V o\t;/^ Y)
Kh.AMApTl iC' ^
\
V s s eV-
CASCAbE N. <y^
lo-Ji^.J, rA^^"''"* >iypu'MA< X',1
SC> '^ ■ \ — ^ I •, w
\y"'i> V I~^ V^- ^ ^
' ^ «?_^ J~. <f'^''JL(| ""'T'^' ><' SIF.RRA
-C'fe( J- \ .=A, \,{<^>i'^yNE^v;uAy••.
VsonomaC sjL". ^'(I'iiA"-^ .yjAi.piNt/.,
EXPLANATION
o
phosphate prospect
1 . Hyampom
2 . Ind ian Creek
3 . Ch ico-Mar t inez Creek
4. Cuyama Va I ley
5. pine Mountain
phosphate occurrence
-^.^
\
\
V 118'
.mon6\ -1—38°
SANTA if^ r'y
(lakaV V ^j
^XMERreqi
'•+ \
^ ^\ ■^KRESN(JO^ , >\ INYOXb \
'-\
v"^^^\W
I ^'^X*"^^ O
■■■' - BARBARA V4H
\
loO MILES
I
M O J A V E -|- --^i-
SAN BERNARDINO '.^
\^LnS ANCELESi \,
^^li&^TT-^ ~^ DESERT >
o.!^.- ^•^TVvr^^^-v
SIDE ;
J
+ \ +
SAN UIEOO
'CS ALTON
\
rjROUG.tii^^^^^
Figure 61. Phosphate in California.
pected by Nicol Industrial Mineral Corp. The phosphate-bearing
strata were exposed and studied in five trenches. Phosphate is con-
centrated in three major zones ranging from about 30 to 65 feet m
thickness. The deposit was not considered economic under current
conditions and was abandoned.
Cuyama Y alley frosfect
Pelletal phosphate rock in the upper part of the Santa Margarita
Formation on the south side of the Cuyama Valley near NeAv Cuyama
is currently being examined by Nicol Industrial Corp. under a Feder-
al phosphate prospecting permit. The phosphate zone has been ex-
posed in 8 trenches. Where best developed the main phosphate zone is
about 100 feet thick.
332 MINERAL AND WATER RESOURCES OF CALIFORNIA
Pine Mountain prospect
Pelletal pliospluite rock in the upper part of the Santa Margarita
F'orniation south of Fine Mountain in Ventura County is currently
being studied by United States Gypsum Co. under a Federal phos-
phate prospecting permit. The phosphate section has been exposed in
o trenches. Where best developed the main phosphate zone is about
100 feet thick.
The pelletal phosphate rock of middle and late Miocene age appears
to otl'er the most promise for economic deposits of phosphate rock in
California. Pelletal phosphate strata in the Santa Margarita Forma-
tion of late Miocene and early Pliocene ( ?) age extending in a south-
east-trending belt through eastern San Luis Obispo, eastern Santa
Barbara, and Ventura Counties looks particularly promising. The
Monterey Formation of middle and late Miocene age in Monterey and
San Luis Obispo Counties also holds promise of containing commer-
cial deposits of pelletal phosphate. The pelletal phosphate horizons in
the lower part (lower Miocene) of the Temblor Formation along the
southeast border of the Coast Eanges and southwest border of the
Great Valley also deserves further attention. The nodular and lami-
nar finely divided phosphatic shales of Miocene age in Santa Barbara,
Ventura, and western Los Angeles Counties are in places more than
200 feet thick and, although of low grade, contain a great amount of
phosphate. If an effective means of beneficiating these shales could
be developed, they could offer significant phosphate resources,
SELECTBa) Refeeences
Gower, H. D., and Madsen, B. M., 1964, The occurrence of phosphate rock in
California : U.S. Geol. Survey Prof. Paper 501-D, p. D79-D85.
Lewis, R. AV., 1964, Phosphate rock : U.S. Bur. Mines Minerals Yearbook 1963, v.
1, p. 877-898.
Lydon, P. A., 1964, Unusual phosphatic rock: California Div. Mines and Geol-
ogy Mineral Inf. Service, v. 17, no. 5, p. 65-74.
Service, A. L., and Popoff, C. C. 1964, An evaluation of the western phosphate
industry and its resources: U.S. Bur. Mines Rept. Inv. 6,485, 86 p.
PLATINUM GROUP METALS
(By W. B. Clark, California Division of Mines and Geology, Sacramento, Calif.)
The platinum group of metals includes platinum, palladium, irid-
ium, osmium, rhodium, and iiithenium. Platinum is the most abun-
dant and most important member of this group. All of these metals
are essential in modern industry and are among the strategic and
critical materials held in the national stockpile. L^nited States pro-
duction of platinum metals is small; most is imported from foreign
sources.
Although platinum is the most important member of the group,
each of the metals has important industrial uses, and each metal ex-
cept palladium commands a price much higher than gold. In May
1965, the average prices per troy ounce were as follows: iridium, $92;
osmium, $250; palladium, $33; platinum, $98; rhodium, $183; and
ruthenium, $58. The uses of platinum and its alloys are based on:
their resistance to corrosion, heat, and oxidation; electrical conductiv-
ity; and superior catalytic properties. The major uses are: (1) cata-
lysts in the production of high-octane gasoline and various chemicals
MINERAL AND WATER RESOURCES OF CALIFORNIA
333
such as sulfuric acid; and (2) alloys for jewelry, dentistry, and elec-
trical apparatus. Platinum is used in laboratory apparatus and ware,
in equipment used in the manufacture of glass and synthetic fibres, and
in certain delicate sensing instruments. Palladium has uses similar
to platinum, as well as in electrical contacts and in nonmagnetic
watches. Tlie other platinum metals are used principally to improve
the hardness and other properties of platinum and palladium. Os-
mium and ruthenium are used in hard alloys for phonograph needles,
fountain pen tips, and fine machine bearings.
In California the platinum-group metals have been found only in
stream placers, chiefly in the Sierra Nevada and Klamath Mountains
(fig. 62). Thus far, no primary platinum-bearing deposits have been
122'
120°
— U4:
EXPLANAT I ON
1 . Butte Creek
2 . Callahan
3 . Coma nc he
4 . C ot t onwood
5. Crescent City
6. F 0 I s om
7 . Hammont on
8 . Hayfork
9. Jenny L i nd
4- 41 " I 0. J unc t i on City
' 1 1 . La Gran ge
Lew I s t on
Michigan Ba r
Mt ne r s V I I le
Crick
Or ov I I I e
Plat I na
Sa I mon River
Se iad
Smith River
S ne I I I n g
Trinity Center
IMrKBlAl-
SAUTON \ ^i3'
115°
Figure 62. Locations where platinum has been recovered in California.
334 MINERAL AND WATER RESOURCES OF CALIFORNIA
found ill the State. Platinum alloyed with the other metals of the
group occurs as small flakes, rounded grains, and irregular lumps in
the placer deposits associated with gold and other heavy minerals at
or near bedrock. The amount of platinum present in placer deposits
in California is small; the average often is one ounce or less per
100,000 cubic yards of gravel.
Platinum and allied metals have been recoA'ered in California as a
by-produot of placer gold mining since the days of the gold rush.
The output of the State since 1850 is estimated to be about 28,000
ounces. The most productive periods were from around 1910 to the
early 1920's, when the annual output averaged more than 500 ounc^,
and from the middle 1930's to the early 1940's, when production ranged
from TOO to more than 1,000 ounces annually. An all-time high of
1,358 ounces was produced in 1940. Some platinum is produced by
the three gold dredges in the Hammonton district in Yuba County.
World production of the platinum-group metals in 1963 amounted
to about 1,530,000 ounces. Russia was the source of approximately
800,000 ounces; Canada, 340,000 ounces; and South Africa, about 300,-
000 ounces. Other sources included the United States with a produc-
tion of 49,000 ounces and Columbia, which yielded 28,000 ounces.
During the early days of mining in the State, most of the platinum
was recovered from hydraulic mines. Later nearly all of it was re-
covered by gold dredges. In the Klamath Mountains, the dredge
fields were in the Klamath-Trinity RiA^er system or in tributaries of
the upper Sacramento River. The hydraulic mines are on terrace
gravel deposits adjacent to these rivers. In the Sierra Nevada, the
hydraulic mines are located chiefly on Tertiary channel gravel deposits
(see also section on Gold). Very small amounts of platinum have
been recovered from beach placers in Del Norte and Humboldt
Counties.
Because all of the platinum metals in California are produced as a
by-product of placer gold mining, the output of these metals will con-
tinue to decrease as gold dredgmg declines.
POTASH
(By G. I. Smith, U.S. Geological Survey, Menlo Park. Calif.)
Potash is a term that means potassium oxide, but it is used widely
to denote several other potassium salts as well. It is an essential
ingredient of fertilizers, and about 94 percent of the potash delivered
to points within the United States is destined for agricultural use.
The bulk of this went to States east of the Mississippi River ; less than
1 percent of this amount went to California. The 6 percent of na-
tional production destined for chemical or industrial uses was also
mostly delivered to eastern states; about 5 percent of that fraction
went to California. In 1963, production of all potassium salts in the
United States Avas about 4,867,000 short tons which were equivalent
to about 2,865,000 short tons of potassium oxide. Their value was esti-
mated to be Jibout $109,000,000, or an average of about $22.40 a ton
for all potassium salts, equivalent to $38.00 a ton of potassium oxide
(Lewis, 1964).
Potash production in the United States was started in the early
1600's. A marketable product was made from wood ashes (thus the
MINERAL AND WATER RESOURCES OF CALIFORNIA 335
name, pot-ash), and by 1635, appreciable quantities were being ex-
])orted. Around 1860, potash was found essential to plant growth,
and, in 1862, the Stassfurt deposits m Gennany began significant pro-
duction. Those deposits dominated the world supply until shortly
after 1900 when minable deposits were found in Alsace (then in Ger-
many, later in France) and in Spain.
Just prior to World War I, the United States started intensive
exploration for domestic sources of potash to replace the threatened
p]uropean suplies. One of the areas studied intensively was Searles
Lake, California, which in 1916 became a major domestic source. At
the close of World War I, at least 127 other plants were also producing
potash in the United States, but only, the one at Searles Lake survived
the postwar decrease in price. -In 1925, potash was discovered in the
Carlsbad district of New Mexico, and in 1931 production started. The
large deposits in Saskatchewan, Canada, were discovered in 1943, and
production started in 1958 (Ruhlman, 1960a, 1960b).
At present, production from the LTnited States supplies about 24
percent of the world total. Other major producing areas of today
lie in West Germany, East Germany, France, Spain, U.S.S.R., and
Israel-Jordan. These supply most of the markets of Europe, Africa,
and west Asia. East Asia, Australia, and New Zealand, though,
import large quantities of potash salts from the United States. In
1963, U.S. exports of potash materials to all countries was 722,000
tons, almost half of which went to Japan. During the same period,
the United States imported 1,041,000 tons of potash materials, over
half of which came from Canada (Lewns, 1964).
About 92 percent of United States production comes from the late
Paleozoic marine deposits in New Mexico. Other production comes
from midergi'ound late Paleozoic marine deposits and late Quarter-
naiy brine deposits in Utah, and from a late Quaternary brine deposit
in California. Some by-product potash material is marketed from
Michigan and Maryland (Lewis, 1964). A possible new source of
potash consists of recently discovered deposits in eastern Arizona
(Chem. Eng. News, 1963; Pierce and Gerrard, 1965).
The only producing deposit in California is Searles Lake. This de-
posit, described in more detail in the chapter on Sodium carbonate, lies
in a closed depression in the southwestern part of the Great Basin of
California. It consists of several saline layers that are permeated with
brines containing the equivalent of between 3 and 5 percent potassium
chloride (table 44, section on Sodium carbonate). Potassium com-
pounds, along with six other products, are extracted from these brines
by means of a complex process at the plant of the American Potash &
Chemical Corp. In 1951, that plant's annual capacity was reported to
be equivalent to 150,000 tons of potassium oxide, and in 1958, it was re-
ported to be 170,000 tons (Ryan, 1951 ; Ruhlman, 1960b) ; these capac-
ities are equal to about 6 percent of national production.
Speculation has existed about the possibility of extracting potash
from the geothermal brines in the Salton Sea area of California. In
1963, five companies were actively exploring the area, primarily as a
source of geothermal power. However, the hot brine contains up to
25,000 ppm potassium (analysis 5, table 10, section on Calcium chlo-
ride) , and one company has announced plans to experiment with the
extraction of potasium salts from it (Lewis, 1964; Chem. Eng. News,
336 MINERAL AND WATER RESOURCES OF CALIFORNIA
1965). Production from this source, however, must await successful
development of first the geothennal power and then the mineral re-
sources, both of which involve solutions to complex engineering
problems.
In the near future, potash production in California will probably re-
main about the same. Production from the Searles Lake deposit is not
likely to change greatly, and in terms of its share in the national
market, might decrease. This is partly because the production of
potash from this deposit must remain coordinated with the demand for
its coproducts, and partly because increased potash production in other
areas will tend to increase the supply available to California and other
nearby markets. The significant production from other areas consists
of the producing deposits in New Mexico which will continue to domi-
nate the domestic supply for many years, the more recently developed
deposits in Utah which may increase production in the future, the area
being explored for potash in Arizona which may someday provide ad-
ditional supplies, and the enormous deposits in Saskatchewan which
may reasonably be expected to develop rapidly into a major source for
the Western Hemisphere.
Selected References
Chemical and Engineering News, 1963, Interest developing in Arizona iwtash
lands : Chem. Eng. News, Dec. 30, p. 18.
— ■ ■, 1965, Morton Salt buys Simonize ; unveils finances : Chem. Eng. News,
May 3, p. 23.
Lewis, R. W., 1964, Potash : U. S. Bur. Mines, Mineral Yearbook, 1963, v. 1, p.
913-927.
Pierce, H. W., and Gerrard, T. A., 1965, Evaporite deposits of the Permian Hol-
brook basin, Arizona [abs.] : Northern Ohio Geol. So. Symposium on Salt, 2d,
Cleveland, 1965, program, p. 3.
Ryan, J. E., 1951, Industrial salts; production at Searles Lake: Mining Eng.,
V. 3, no. 5, p. 447-452.
Ruhlman, E. R., 1960a, Potash, in Industrial minerals and rocks : New York, Am.
Inst. Mining Metall. Petroleum Engineers, p. 669-680.
— ; 1960b, Potassium compounds, in Mineral facts and problems: U.S. Bur.
Mines Bull. 585, p. 651-658.
PUMICE, PUMICITE, PERLITE, AND VOLCANIC CINDERS
(By C. W. Chesterman, California Division of Mines and Geology, San Francisco,
Calif.)
Pumice, pumicite, and volcanic cinders are products of explosive
volcanic activity. Pumice is a very cellular, pale-gray to white vol-
canic glass that occurs in fragments greater than one-eighth inch in
diameter and in masses as much as 10 feet across. Pumicite, also known
as volcanic ash, consists of finely divided angular glass particles, less
than one-eight inch in diameter. The distinction between pumice and
pumicite is one of particle size rather than structure or composition.
Perlite, strictly defined, is a glassy volcanic rock characterized by an
"onion skin" fracture, and which breaks into minute spherical frag-
ments. Perlite, as well as many other siliceous volcanic glasses, will,
when subjected to rapid controlled heating, expand into a Avhite, frothy
material that resembles pumice. In an industrial sense, all expansible
volcanic glasses may be referred to as perlite.
''\/'olcanic cinders (scoria) resemble furnace clinkers and consist of
small crystals of plagioclase and pyroxene enclosed in a mesh of still
MINERAL AND WATER RESOURCES OF CALIFORNIA 337
smaller crystals of these minerals and subordinate dark-colored vol-
canic glass.
Pumice is used principally as aggregate in the production of light-
weight concrete, and as an abrasive. Although some pumicite is used
as a pozzolan in the production of concrete and as an abrasive, its
principal usage is as a pesticide carrier for agricultural sprays.
About 40 percent of the perlite produced and expanded in the United
States is used as aggregate in plaster. Other uses for expanded
perlite include concrete aggregate, foundry sand, filter aid, filler, wall-
board, and soil conditioning.
Volcanic cinders find their greatest use in highway and railroad
building. Minor, yet substantial, amounts of volcanic cinders are used
as aggregate in concrete building blocks, monolithic concrete construc-
tion, stucco, roofing granules, decorative stone in gardens, and as a con-
ditioner of soils.
^~ Pumice, pumicite, perlite, and volcanic cinders commonly occur to-
gether and exist in California in regions underlain by Tertiary and
Quaternary volcanic rocks. Pumice rarely forms seperate rock masses
and is generally the major constituent of tuff and tuff-breccia. Massive
pumice, however, can be found as tops of flows and domes of obsidian.
Pumicite generally occurs as layers interbedded with fine-grained
sediments.
Since most of the pumice and pumicite mined in California is ob-
tained from tuffs, tuff-breccias, and pumice breccias, their deposits
may be classified, on the basis of their mode of deposition and origin
as follows: (1) subaerial deposits — those deposited on dry land, (2)
subaqueous deposits — those deposited in standing water, (3) Nuee
ardentes deposits — lack bedding and show wide range in grain size,
and (4) reworked deposits — show graded bedding, cross-bedding, and
rounded fragments.
The bulk of the pumice and pumicite produced in California has
been from subaqueous and subaerial types of deposits. Deposits of
subaerial pumice range in thickness from a few feet to 50 feet, and
have an aerial extent of several square miles; subaqueous deposits
range in thickness from a few feet to 30 feet, and are of considerable
aerial extent.
olcanic cinders are mined from cinder cones which formed around
central openings or along fractures during explosive volcanic activity.
Cinder cones are, in general, nearly circular in plan, range from a few
hundred feet to several thousand feet in diameter, and are as much as
I 500 feet high. The cones are stratified and consist largely of frag-
\ ments that range from a fraction of an inch to several inches in
L-diameter.
Although perlite has many modes of occurrence, most commercial
production has come from flows associated with thick accumulations
of tuffs and lava flows, and from domes. In many places, flows of
perlite-bearing rock are so recent that they are nearly flat-lying, but
locally they are deformed. Individual flows of perlite range in thick-
ness from a few feet to several tens of feet, and may be traced along
their outcrop length for thousands of feet. Perlite domes range in
size from several hundred feet to more than a mile in diameter, and
frequently extend as much as several hundred feet above their base.
The early known uses of pumice and pumicite date back to the days
338 MINERAL AND WATER RESOURCES OF CALIFORNIA
of the Roman Empire when pumicite was mixed with burned lime
and used in the construction of the Pantheon and harbor installations
on the Tiber. Many buildings in Belgium and France were built of
pumice concrete during the 19th century. Ground pumice has been
used as an abrasive for many years in the United States. Although
only a limited amount of pumice was used as concrete aggregate
prior to 1930, by the mid-1930's the demand for lightweight aggre-
gate materials for military and domestic consumption had increased
substantially, and consequently the production of pumice increased
accordingly.
It has been known since about 1886 that perlite would expand,
when properly heated, into a white, lightweight material. During
the 1930's and early in the 1940's, research was conducted on the ex-
pansion of perlite, and by 1945 a new industry was established and a
new product— popped or expanded perlite — was introduced to the
construction world. A wide variety of furnaces were designed, rang-
ing from inclined stationary and rotary to vertical stationary. In
each case, the purpose was to produce a consistently lightweight
material (8 to 10 pounds per cubic foot) with a minimum of fines.
The early use of volcanic cinders, undoubtedly, dates back several
hundred years, but accurate records concerning where and when they
were first used are scarce. The mining of volcanic cindei's in Cali-
fornia was started about 1916 on a small scale, and the early uses were
for concrete aggregate and as track ballast in railroad construction.
The United States ranks third among the nations in the production
of pumice, pumicite, and volcanic cinders, and first in the production
of crude perlite.
The annual production of pumice and pumicite in California has
increased markedly from about 50 tons in 1909 to about 160,000 tons
in 1964, as compared with tlie total United States production of over
1,000,000 tons. California's peak production of pumice and pumicite
isjipproximately 260,000 tons, attained in 1951.
California ranks first in the Ignited States in the production of
(volcanic cinders, and was the source of about 300,000 tons in 1964 as
compared to a total United States production of about 1,600,000 tons.
^rude perlite processed in the United States is mined from deposits
in New Mexico, California, Arizona, Nevada, Colorado, I^tah, and
Idaho. New Mexico produces approximately 75 percent of the total
United States production, and (California is among the other impor-
tant producing states.
In 1964, there were 14 perlite expanding plants operating in Cali-
fornia. Eleven of these plants are located in southern California and
provide a wide range of expanded perlite products to consumers in
this part of the State. There is one plant at Fresno and two in the
San Francisco Bay area, at Antioch and Sausalito.
Most of the pumice and pumicite deposits in California are in areas
underlain in part by Tertiary and Quaternary volcanic rocks. Al-
tliough considerable pumice and pumicite have been produced from
tuffs of late Pliocene age, the bulk of California's output of these
materials, as well as volcanic cinders, has come from tuffs and tuff-
breccias of Pleistocene and Recent age. - »
The distribution of the principal deposits, deposits from which
there has been commercial production, or deposits which warrant fur-
ther consideration are shown in table 37 and figure 63.
MINERAL AND WATER RESOURCES OF CALIFORNIA
339
Table 37. — Summary of the features of pumice, pumicite, perlite, and volcanic
cinder deposits of California
Commodity
Name of deposit
Pumice..
Thompson ..
...do...
Boorman
do
U.S. Pumice and Supply
Co., Inc.
.do.
Skoria Star Brick Co
Pumice Stone mines
Weisman
do
Pumice and pumi-
cite.
Volcanic cinders
Kegg
do-.
Great Northern Railroad.
do
Porcupine Pit
do
Shastalite
Pumice
Long Haul Claims
Volcanic cinders
Sanford Cinders.
do
Poison Lake Cinders
do
Pumice
Bowen Cinder
William Silva .
do
Volcanic cinders...
Pumice. _____ .
Basalt Rock Co. pumice
deposit.
Cinder Products
Coleman
Volcanic Ash Pit
do
do
Sierra Placerite Corp
Pumice and pumi-
cite.
Bed Rock piimicite
Pnmice
U.S. Pumice and Supply
Co., Inc.
.__- do -.
Victory..
do
Van Loon "Fine" west
do
Snoeshoe
Brewster
do
Remarks
Pumice for aggregate purposes is mined from
extensive layer, 10 to 40 feet thick, of loosely
consolidated tuff-breccia.
Pumice for aggregate purposes is mined from
extensive layer, 3 to 6 feet thick, of loosely
consolidated tufT-breccia.
Pumiceous obsidian is quarried from top of
Glass Mountain and used in the production
of scouring bricks.
Pumiceous obsidian is quarried from top of
Glass Mountain and used in the production
of scouring bricks.
Pumice occurs as loosely consolidated tuff
covering the ground and ranging in thickness
from a few inches to 10 feet.
Pumicite and pumice were mined from an
extensive layer of white tuff which ranges in
thickness from a few feet to 20 feet, and used
as sand in cattle cars.
Volcanic cinders mined from a cinder cone and
used as ballast in railroad construction and
repair.
Volcanic cinders produced from East Sand
Butte, an extinct cinder cone. Material used
principally as railroad ballast and bank
widening.
Volcanic cinders produced from cone at Porcu-
pine Port, Siskiyou County. Material used
in railroad construction.
Volcanic cinders produced from extinct cinder
cone 1 mile east of Hotlum. Cinders used as
aggregate for making building blocks.
Pumice is mined for aggregate purposes from
extensive tuff-breccia layer that ranges in
thickness from 5 to 10 feet.
Red and black volcanic cinders are quarried
from eroded cinder cone and used as concrete
aggregate.
Dark red and black volcanic cinders are quarried
from cinder cone and used as concrete aggre-
gate.
Do.
Pumice mined from 20-foot-thick layer of tuff
and used as concrete aggregate.
Pumice for aggregate purposes was produced
from massive tuff of unknown thickness.
Red volcanic cinders are quarried from eroded
cinder cone and used as concrete aggregate.
Coarsely vesiculated obsidian is quarried for use
as aggregate in plaster and concrete.
Sand from coarsely vesiculated obsidian is
mined from extensive deposit and used as fill
and in construction.
Firm consolidated, yellowish- to buff-colored
rhyolite tufl is quarried and sold as flagstone,
ashlar strips, garden stone, and used in the
making of terrazzo.
Beds of grayish-white pumicite of variable
thickness are interbedded with beds of silt
and tuflaceous sand. Some pumicite produced
and sold under trade name of "Lassenite".
Vesiculated obsidian is quarried from tops of
volcanic domes and used in the manufacture
of scouring bricks.
White pumice for aggregate purposes is mined
from a 20-foot pumice bed.
Pale pink pumice was mined from several
quarries and used as aggregate for making
building blocks.
Several pumice beds with aggregate thickness
of 30 feet were mined by benches and the
pumice used as aggregate for making building
blocks.
Layer of pumice 20 feet thick, containing pink
to white pujnice fragments, is mined and the
pumice used as aggregate.
340
MINERAL AND WATER RESOURCES OF CALIFORNIA
Table 37. — Summary of the features of pumice, pumicitc, perlite, and volcanic
cinder deposits of California — Continued
Index
No. on
fig. 63
CoTnmodity
Name of deposit
Remarks
27
.... do
Van Loon "Fine"
Pale pinkish pumice for aggregate purposes is
28
29
do
do
Insulating Aggregates, Inc.
Ray Gill and Donna
Inyo Pumice Corp
Lucky Lager^ ...
mined from an extensive layer of unknown
thickness and used in making building blocks
and precast slabs.
Extensive layer of grayish-white pumice is
mined by open cut and the materia is ground
and made into plaster aggregate.
Extensive layers of pumice are being mined for
30
_._. do.. ----
aggregate pumice.
Creamy-white pumice has been mined for ag-
31
do
gregate purposes from a layer of tuff about 30
feet thick.
Creamy-white pumice has been produced from
32
do....
Pumicite
do
Calsiico Corp _
a tuff bed of unknown thickness and used as
aggregate in the manufacture of building
blocks.
Purr.''*" for aggregate and abrasive uses is being
33
34
Cudahy Packing Co.,
"Seismotite".
Shoshone volcanic ash
(pumicite).
Redlite Aggregates
Splane
produced from a bed of pumice lapilli tuff
about 20 feet thick.
White, fine-grained pumicite was mined from a
9-foot bed in the Ricardo Formation (Plio-
cene).
Flat-lying layer of grayish-white pumicite,
35
36
Volcanic cinders...
do-.
Pumice
do
Volcanic cinders. . .
.. do
about 12 feet thick interbedded with lacus-
trine sediments has been mined intermit-
tently and the pumicite used in the manufac-
ture of scouring soaps and cleansing com-
pounds.
Volcanic cinders produced from Red Cinder
Mountain, cinder cone, for aggregate pur-
poses.
Volcanic cinders for aggregate, roofing granules,
37
Kleen-Gro
and agricultural purposes.
Pumice for aggregate and abrasive uses is being
38
Su perlite.
obtained from a thick tuff layer interstrati-
fied with other tuffs that rest upon deeply
eroded granite.
Pumice for aggregate uses mined from tufl
39
Mount Pisgah
lavers associated with sands and gravels.
Volcanic cinders used for aggregate.
40
Dish Hill
Pinto Cinders... .__
Cima Cinders
Volcanic cinders for aggregate and roofing
granules.
Volcanic cinders Quarried from cinder cone and
41
do
42
do
Pumice
Pumicite.. -.
Perlite
do
used as concrete aggregate, stucco, and soil
conditioner.
Do
43
44
45
Pumice and Pumicite
Mining Co.
California Industrial
Minerals Co.
Perlite Aggregates ...
Pumice for aggregate purposes is produced from
a laver of tuffaceous sandstone which has a
maximum thickness of 30 feet.
Buff-colored pumicite is produced from a 20-foot
bed of p-imicite and used as insecticide carrier,
in scouring soaps, manufacture of cement,
and polishing agent.
Medium-gray, dense perlite has been quarried
46
Anadel Farm.. __
from an extensive flow that ranges in thick-
ness from a few feet to 100 feet, and overlain
by tuff.
Medium-gray, dense perlite has been quarried
from an extensive flow that ranges in thick-
ness from 25 to 50 feet, and overlain in part
by basalt flow.
Extensive area underlain by a glassy flow com-
posed of perlite and obsidian.
Liglit-gray perlite is quarried from an elon-
47
do
do
do.....:.-.....
Cougar Butte.. ..
48
Fish Springs .
49
Glassy Rock
gated dome of pumiceous perlite that meas-
ures H mile wide and 1 mile in length.
Medium-gray, dense perlite has been quarried
from an extensive, gently southward-dipping
flow that ranges in thickness from a few feet
to 50 feet, and interbedded with tufl and
tuffaceous sediments.
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANATION
341
Figure 63. Pumice, pumicite, perlite, and volcanic cinder deposits in California
( numbers refer to table 37 ) .
Resources potential of pumice, pumicite, perlite, and volcanic cind-
ers is extremely great in California. No attemj)t is made to indicate
reserves of these materials, because many of the deposits have never
been examined carefully, and, as in the case for perlite, any reserve
data would be meaningless unless such factors as uniformity and a
definition of acceptable quality are known.
Selected References
Chesterman, C. W. 19.57, Pumice, pumicite, perlite, and volcanic cinders, in
Mineral commodities of California : California Div. Mines Bull. 176, p. 433-448.
Chesterman, C. W.. and Schmidt, F. S. 1956, Pumice, pumicite, and volcanic
cinders in California : California Div. Mines Bull. 174, 119 p.
Wright, L. A., Stewart, R. M., Gay, T. E., Jr., and Hazenbush, G. C, 1953, Mines
and mineral resources of San Bernardino County, California : California Jour.
Mines and Geology, v. 49, nos. 1 and 2, p. 185-190.
342 MINERAL AND WATER RESOURCES OF CALIFORNIA
PYROPHYLLITE
(By L. A. Wright, Department of Geology and Geophysics, The Pemisylvania
State University. University Park, Pa.)
Use and Economic Importance
Pyrophyllite (Al2Si40io(OH)2), like the mineral talc, is vei-j^ soft,
micaceous in habit, soapy to the touch, and chemically inert. It is
thus difficult to distinguish from talc. As industrial mmerals, they
share most of the same uses and are competitive for the same markets.
If sufficiently \vhite in the ground state and free of impurities, pyro-
phyllite is useful as a paint extender. "Wliite-firing pyrophyllite is
employed in the manufacture of ceramic products and of wall tile in
particular. Pyrophyllite that grinds relatively dark is extensively
marketed as an insecticide carrier and as a filler in various products,
including asphalt and rubber (Chappell, 1960, p. 84-85). In 1963 an
estimated 20,000 tons of pyrophyllite -was mined in California and was
marketed mainly within the State. About 25 percent of this output
was used in paints and ceramics. As most of the pyrophyllite that has
been mined in California has proved too dark in color for these uses,
it has been marketed principally as an insecticide carrier and filler.
Geologic Occuerence
Concentrations of pyrophyllite that are large enough to be of com-
mercial interest occur in terranes of metamorphic rocks. Most of them
can be shown to represent alterations of silicic volcanic rocks. The
pyrophyllite of commerce consists of a schistose rock composed of
a fine-grained mineral aggregate in which the mineral pyrophyllite
is the most abundant constituent, but which commonly also contains
abundant quartz and sericite. This rock occurs in tabular to highly
irregular deposits. The most productive of the domestic sources of
pyrophyllite are in North Carolina where bodies as much as 1,500
feet long and 150 feet wide have been developed. Most of these
deposits are lenticular in plan and appear to be best developed where
the enclosing volcanic rocks have been thoroughly sheared.
History of Discov'ery and Developihent
The formal mining of pyrophyllite in California began in the early
1940's with the opening of the Pioneer deposit near San Dieguito,
west-central San Diego County (Jahns and Lance, 1950). This de-
posit was most actively worked in the middle and late 1940's. It
and several nearby deposits have been intermittently operated in re-
cent years.
The most productive pyrophyllite deposits in California are along
the lower part of the west face of the White Mountains of Mono
MINERAL AND WATER RESOURCES OF CALIFORNIA
343
County (Wright, 1956, p. 455). These were opened in the mid-1940's
and have been ahnost continuously worked since then, first at the
Pacific mine and, in recent years, at the Colton mine.
A third pyrophyllite-bearing area in California lies 12 miles north-
east of Victorville in San Bernardino County. There the Victorite
deposit (Wright and others, 1953, p. 243-244; Bowen, 1954, p. 158-
160) , has been worked intermittently beginning about 1950.
The only domestic sources of pyrophyllite are in North Carolina
and California. In recent years the two states have yielded about
150,000 tons annually. The output of North Carolina is several times
that of California.
Geologic Occukrenck in California
The pyrophyllite deposits near San Diguito, San Diego County,
and those near Victorville, San Bernardino County (figure 64), occur
in volcanic rocks of Mesozoic age and are alterations of them. The
bodies of pyrophyllite-bearing rocks are lenticular in shape. The
mineable bodies are characteristically a feAv feet to a few tens of feet
wide and as much as a few hundred feet in length. They form parts
of much larger masses composed mostly of partially pyrophyllitized
rock of no present commercial value.
PYROPHYLLITE OPERATIONS
IN CALIFORNIA
I . Pac 1 1 ic Mine
2. Colton Mine
3 . Victorite Mine
4. Pioneer Mine
Figure 64. Pyrophyllite operations in California.
344 MINERAL AND WATER RESOURCES OF CALIFORNIA
The deposits in the Wliite Mountains occur in a belt of highly meta-
morphosed volcanic and sedimentary rocks of pre-Cretaceous age.
These deposits are bordered by mica schist and quartzite and commonly
contain highly quartzose layers of waste rock. The deposit at the
Pacific mine appears to be the largest of the pyrophyllite bodies dis-
covered to date in California. It is about 200 feet wide at the main
quarry and appears to extend laterally for 1,000 or more feet. The
commercial pyrophyllite is a friable schistose rock most of which is
stained various shades of red, yellow or orange. Some of it is white
or nearly so and is mined selectively. The Colton mine is about 2 miles
south of the Pacific mine and in the same pyrophyllite-bearing belt.
It has yielded relatively white pyrophyllite from a deposit that is
about 100 feet in maximum exposed thickness and at least several
hundred feet long.
Resource Potential
Meaningful estimates of the pyrophyllite resources in California are
as yet unavailable because the deposits of the "WHiite Mountains and
those near Victorville remain to be studied in detail. The three areas
already noted contain many millions of tons of rock that is sufficiently
rich in pyrophyllite to be of commercial interest. But the proportion
of this tonnage that ultimately will prove salable and that can be
mined at a profit will depend on future use patterns, future industrial
specifications, and mining costs, as well as upon the size of the depos-
its. The resources of pyrophyllite in the AYhite Mountains appear to
be especially large and capable of sustainins; the present rate of pro-
duction for several tens of years and probably mvich longer.
Deposits of pyrophyllite in California, in addition to those already
mined or prospected, aj)pear most likely to be discovered within the
known pyrophyllite-bearing belts. The most obvious prospecting
sites at present are at localities where the known mineralized zones
extend beneath shallow covers of alluvium or talus. The principal
problem in such exploration is the delineation of bodies of commercial
pyrophyllite within much larger bodies of marginal or subcoimnercial
material.
Selected References
Bowen. O. E., Jr.. 1954, Geology and mineral deposits of Barstow quadrangle,
Califoniia : California Div. Mines Bull. 196."), p. l.")8-160.
Chappell, Fred. 1960. Pyrophyllite. hi Industrial minerals and rocks; Am. Inst.
Mining Metall. and Petroleum Engineers, ,3d ed., p. 681-686.
.Tahns, R. H., and Lance, J. F., 19.50, Geology of the San Diguito pyrophyllite area,
San Diego County, California : California Div. Mines Spec. Rept. 4, 32 p.
Weber. F. H., .Jr.. 1963, Mines and mineral resources of San Diego County,
California : California Div. Mines and Geology County Rept. No. 3, p. 203-208.
Wright, L. A., 1956, Pyrophyllite. in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176. p. 451--458.
Wright. L. A.. Stewart, R. M., Gay, T. E.. .Jr., and Hazenbush, G. C, 1953. Mines
and mineral deposits of San Bernardino County, California : California Jour.
Mines and Geology v. 49, p. 243-244.
QUARTZ CRYSTAL
(By Cordell Durrell, Department of Geology, University of California, Davis,
Calif.)
Quartz crystals are used principally as oscillator plates for fre-
quency control in electronics. Other uses are for lenses and prisms in
optical devices, for the production of silica glass which has many
MINERAL AND WATER RESOURCES OF CALIFORNIA 345
scientific and industrial uses, and for ornamental purposes including
jewelry.
World production of quartz crystal in 1963 exceeded 1,500 t(ms,
nearly all of which came from the alluvial deposits of Brazil. Coini-
tries with small production include Japan, Peru, the Malagasy
Republic, and other countries. Production in the United States is
virtually nil. In 1963 the United States imported 141 tons and con-
sumed 162 tons of quartz. The latter figure includes reworked scrap
and manufactured crystal which amounted to 35 tons. Manufactured
crystal is made from scrap and loAver grade quartz crystal.
Quartz crystals occur in veins, often associated with ores, in rocks
called pegmatite, and secondarily in alluvial deposits that have origi-
nated mostly through the action of streams. Practically all of the
world production is from alluvial deposits.
Quartz crystal is present in innumerable places in California. It is
found in pegmatites, especially in San Diego County and in Kern
County in the southern Sierra Nevada; it is present in tactite also in
the southern Sierra Nevada; in veins in the northern Sierra Nevada;
and it is present in the ancient river channels of the central Sierra
Nevada. Few occurrences are reported from the Klamath Mountains
and the Mojave Desert, and Great Basin, and significant occurrences
are lacking in the Coast Ranges and the Modoc Plateau.
Most of the known occurrences contain, or contained, crystals too
small and too flawed for industrial use, although many of them have
yielded crystals useful for mineral specimens, jewelry, or other orna-
mental purposes. Crystals exceeding 2 inches in diameter are de-
cidedly uncommon.
Only one California deposit has produced important quantities of
quartz crystal for industrial purposes. This is an occurrence of
crystals as boulders in an ancient river bed known as the Tunnel Ridge
Chamiel, 2i/^ miles southeast of Mokelumne Hill (fig. 65, no. 1) . The
two adjacent underground mines from which the crystal was obtained
Avere known variously as the Green Mountain, McSorley, Calaveras
Crystal Mine, and the Rough Diamond Mine. They are in the SE14
sec. 24 and NE14, sec. 24, T. 5N., R. 12E., M.D.
Crystals here were first reported in 1897 and 1898, and were pro-
duced during World War I and World War II, and once in between.
More than two tons of crystals were taken out during World War 11.
The total production is unknown but is probably several times that.
Single crystals weighed as much as 200 pounds, and one w^as reported
to weigh a ton. Clusters of two to a dozen crystals recovered during
the latest operations weighed as much as 600 pounds. Only a small
part — on the order of 10 percent — of each crystal was unflawed and
useful. Although the crystals did not travel far as is evidenced by
the total absence of wear, the primary source has not been found.
The probability of again establishing commercial production from
any known deposit in California is small, but one other occurrence
would merit investigation in case an emergency need for crystals
should arise (fig. 65, no. 2). Crystals, and cobbles worn from single
crystals, are present on the dump of the Pigeon mine which penetrated
an ancient river channel on the ridge betw^een Dry Creek and Big
Indian Creek, about li/^ miles northeast of Fiddletown. Similar
67-1,64 o— 66^pt. I as
346
124
MINERAL AND WATER RESOURCES OF CALIFORNIA
123" 122° 121°
Qua r t z crystal de pos i t s
MoKel umne Hill
Fidd le t own
Figure 65. Quartz crystal deposits in California.
materials are reported to be present also in the Sharp Mine, three-
fourths of a mile east of the Pigeon mine. The channel between
these two mines possibly contains quartz crystal of commercial value,
but of midetennnied amount.
Selected References
Clark, W. B., and Lydon, P. A., 1962, Quartz crystals, in Mines and minerals
resources of Calaveras County, California : Cialifornia Div. Mines and Geology
County Kept. 2, p. 106.
Durrell, C. 1944, Geology of the quartz crystal mines near Mokelumne Hill,
Calaveras County, California : California Div. Mines, Rept. of the State Min.,
1944, chap. 4, p. 42^-433.
U.S. Bureau of Mines, Minerals Yearbook : vol. 1, 1963. Chapter on quartz
crystal. See other volumes in this series.
QUARTZITE AND QUARTZ'
(By D. C. Ross, U.S. Geological Survey, Menlo Park, Calif.)
Quartz is the most common form of silica (SiOo), one of the most
abundant compounds in the earth's crust. Tightly cemented aggre-
gates of quartz grains or aggregates tliat have been subjected to heat
and pressure make up a common rock known as quartzite. Quartz,
and rocks composed of quartz, have many diversified uses in industry
and the arts because they are : ( 1 ) common and in large, easily exploited
1 Largely abstracted from Clark and Carlson (1957).
MINERAL AND WATER RESOURCES OF CALIFORNIA 347
deposits, and consequently cheap to produce; (2) hard; (3) resistant
to ordinary chemical action and weathering; and (4) highly resistant
to heat (refractoriness).
Sand and gravel, which are used mostly for construction purposes,
even though they are commonly quartz-rich, are excluded from this
section as are specialty sands such as glass sands and foundry molding-
sands (see Sand and gravel chapter). Likewise quartz crystals are
treated separately (see Quartz crystal chapter). This chapter is lim-
ited to quartz as used for industrial silica, which is widely used in
abrasives, silica firebricks, metallurgical fluxes, filters, ferrosilicon,
as a mineral filler and in ceramics and portland cement. Quartz and
quartzite must be quite pure, easily mined, and near transportation
facilities, however, to be of commercial interest. Silica from quartzite,
vein quartz, quartz-rich gravel, and pegmatite quartz have been pro-
duced commercially from several California areas — quartzite is mined
most abundantly, and is used principally in the manufacture of silica
bricks and as a source of silica in portland cement.
Geologic Occurrence
The mineral quartz, next to the feldspars, is the most abundant
mineral in the earth's crust, it makes up about 12 percent of the crust.
It occurs as crystals and ci^ystal aggregates as well as in massive and
granular forms. It is quite hard (7 on the Mohs' hardness scale),
generally colorless to white, and highly resistant to chemical weather-
ing. Crystals of quartz are common in many granitic igneous rocks
and in some volcanic rocks. Quartz is also common in veins as the
gangue (waste material) of many ore deposits. Largely because of
its resistance to. chemical weathering and alteration, quartz tends to
concentrate in the weathering cycle, and sedimentary rocks composed
almost entirely of quartz grains (quartz sandstone) are abundant.
Cementation of these quartz sandstones with silica cement or the appli-
cation of heat and pressure changes sandstones to the tough, resistant
rocks known as quartzite. The name "ganister" is sometimes used
commercially for pure quartzite.
Quartz veins most commonly occur in granitic igneous rocks or in the
wall rocks near granitic rocks. These veins range in size from small
stringers an inch or less wide and a few inches long to massive, resist-
ant bodies many tens of feet wide and miles long. Many quartz veins
are pure, but some contain sulfide minerals such as pyrite, native gold,
calcite, and many other minerals. Quartz-rich river gravels are com-
mon in areas where quartz veins are abundant.
Granitic pegmatites are another common source of quartz. Most
pegmatite bodies occur in granitic rocks and are a coarse-grained inter-
growth of principally feldspar and quartz. Quartz crystals several
inches or even a few feet in diameter are not uncommon in large
pegmatite pods.
Occurrence in California
Quartzite, vein quartz, and quartz gravel are abundant and wide-
spread in California; quartz in pegmatite is more restricted in occur-
rence, Quartzite occure most abundantly in the Great Basin and the
Mojave Desert, and also in the Klamath Mountains, Coast Ranges,
348 MINERAL AND WATER RESOURCES OF CALIFORNIA
Sierra Nevada, and Peninsular Ranges. Quartz veins are most com-
mon in tlie western foothills of the Sierra Nevada, but also are locally
abundant in other mountainous regions of the State. Quartz gravels
derived largely from quartz veins are coimnon in Recent and Tertiary
stream channels in the Sierra Nevada. Quartz in gi-anitic pegmatite
is mostly found in the Peninsular Ranges.
The principal source of quartzite production in California has been
from quartzite layers in the Oro Grande Formation of Carbonifer-
ous ( ?) age near Victorville. The silica content ranges from 98.5 to
9D.1 percent in this tough, massive, pink rock that is used chiefly for
Portland cement and for silica refractories (silica brick).
In the Great Basin and Mojave Desert provinces of California, sev-
eral pure quartzite formations are widespread. The Stirling Quart-
zite of late Precambrian age crops out over a large area in the Death
Valley region and contains some remarkably pure parts. In the same
region the Zabriskie Quartzite of Early Cambrian age is also present.
Though not so thick as the Stirling, it is widespread and exception-
ally pure. Within the Harkless Formation of Early Cambrian age in
the Inyo Mountains thick jmre quartzite is exposed over large areas.
The Eureka Quartzite of Ordovician age is remarkably pure quart-
zite, a few hundred feet thick, which is exposed extensively in the Great
Basin. These occurrences represent an almost inexhaustible supply
of pure quartzite, but they are, for the most part, a considerable dis-
tance from population centers and many outcrops are far away from
suitable transportation at present. In the southern Inyo Mountains,
however, the Eureka Quartzite has been quarried to some extent and
the quartzite utilized in the manufacture of silica brick and other in-
dustrial uses.
Massive quartz veins are widespread in the western foothills of the
Sierra Nevada. These veins are most common in the ^lother Lode
belt, a system of linked quartz veins extending for more than 100
miles. Many of the veins contain gold and sulfides, but some barren
veins have been a source of silica. One vein at White Rock in western
Mariposa County, west of the ]\Iother Ix)de, crops out for a distance of
300 feet and is 150 feet wide. This white "bull"' quartz was quarried in
the 1940's and 1950"s and used to manufacture ferrosilicon. Mostly in
the 1920"s and 1930-s vein quartz was mined in the foothills of Tuo-
lumne, Calaveras, El Dorado, Fresno, and Placer Counties, and used
for fluxing material in steel furnaces, and as abrasives and scouring
powder. A massive quartz vein of the Mother Lode belt south of Jack-
sonville is quarried, crushed, bagged and sold as turkey grit. Vein
quartz was also mined to a lesser extent in the Transverse Ranges of
Los Angeles County, in the Coast Range in Stanislaus County, and in
the Klamath Mountains. For the past few years quartz gravels have
been mined from the Bear River and sent through a grinding plant at
Colfax. The quartz is crushed and then fine ground for use in scour-
ing powder.
Quartz from pegmatite deposits comes chiefly from the Peninsular
Ranges of San Diego and Riverside Counties, though some has been
produced from Kern and Imperial Counties. The largest operations
were near Murrieta in Rivereide County, where quartz was used in
abrasives and ceramics in the 1920's and 1930's; much of the pegmatite
MINERAL AND WATER RESOURCES OF CALIFORNIA 349
quartz is a byproduct of feldspar mining. Other pegmatite quartz
production has come from near Nuevo and Winchester in Kiverside
County, and from the Jacumba and Live Oak Spring areas in San
Diego County. Some pegmatite quartz production also comes from
near Rosamond in Kern County.
Resource Potential
The supply of high-quality quartzite is virtually unlimited for the
foreseeable future in the Great Basin and the Mojave Desert. Vein
quartz material is extremely abundant in the western Sierra Nevada
foothills. Quartz gravel is likewise abundant in some Sierra Nevada
river channels, but not too common elsewhere in the State. Pegmatite
quartz in quantity is mostly limited to the Pennisular Ranges and at
present its production depends on feldspar mining. Quartzite and
quartz are at a disadvantage to quartz sand for uses that require a
fine-grained source of silica. The crushing and grinding required to
reduce quartzite and quartz to fine-grain size are expensive and meas-
ures to reduce the hazard of silicosis also add to the cost of crushing
and grinding.
The present pattern of production consists of relatively small pro-
ducers and a somewhat stable, but small market. Some of the produc-
tion of silica for industrial uses is esentially a by-product of quartzite
and quartz production for construction uses.
Future production is not dependent on raw material so much as on
mining and marketing costs. Many large bodies of pure quartzite
are now amenable to quarrying but they are not cormnercial 'because
they are long distances from adequate road and rail transportation.
The major California market for quartzite is the Los Angeles metro-
politan complex and other mushrooming urban areas. Commercial
growth and development in these areas means mcreasing needs for
industrial silica. The quartzite deposits of the Great Basin and the
Mojave Desert are a readily available source to suppy these future
needs.
Sexected References
Bowen, O. E., Jr., 1954, Geology and mineral deposits of Barstow quadrangle,
San Bernardino County, California : California Div. Mines Bull. 165, p. 7-185.
(silica, ganister, p. 174-179)
Clarke, W. B., and Carlson, D. W., 1957, Quartzite and quartz : California Div.
Mines Bull. 176, p. 463-466.
Clark, W. B., and Lydon, P. A., 1962, Silica, in Mines and mineral resources of
Calaveras County, California : California Div. Mines and Geology County
Rept. 2, p. 107-109.
Ladoo, R. B., and Myers, W. M., 1951, Nonmetallic minerals, 2d ed. : New York,
McGraw Hill Book Co., Inc., 605 p. (quartz and silica, p. 419-431)
Sampson, R. J., and Tucker, W. B., 1931, Feldspar, silica, andalusite, and cyanite
deposits in California : California Div. Mines. 27tli Rept. State Mineralogist.
(silica, p. 432-450)
Ver Planck, W. E.-, 1962, Quartz and feldspar, in Mines and mineral resources
of Kern County, California : California Div. Mines and Geology County Rept.
1, p. 265-266.
Weber, F. H., Jr., 1963, Quartz (including quartz crystal) and quartzite, in
Geology and mineral resources of San Diego County, California: California
Div. Mines and Geology County Rept. 3, p. 208.
Weigel, W. M., 1927, Technology and uses of silica and sand : U.S. Bur. Mines
Bull. 266, 199 p.
350 MINERAL AND WATER RESOURCES OF CALIFORNIA
RARE EARTHS
(By J. W. Adams, U.S. Geological Survey, Denver, Colo.)
The rare-earth metals comprise the 15 elements having atomic num-
bei*s 57 to 71. They include lanthanum (La), cerium (Ce), praseo-
dymium (Pr),]ieodymium (Nd),promethium (Pm), samarium (Sm),
europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy),
holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and
lutetium (Lu). One of these elements, promethium, has been known
only as an artificially produced isotope until its recently reported dis-
covery as a trace constituent of the rare earths recovered from apatite
in a phospate plant in Finland (U.S. Bur, Mines, Mineral Trade Notes,
1965). Yttrium (Y), with atomic number 39, is also classed with the
rare earths because of its chemical similarities and geochemical
affinities.
The first seven elements listed above (La through Eu) are included
in the cerium group of rare earths, so called because cerium is their
most abundant member. The remaining eight elements (Gd through
Lu), together with yttrium, are called the yttrium grovip. The two
groups are also referred to, respectively, as the "light" and "heavy"
rare earths.
The properties of the members of the two groups of rare earths
are sufficiently distinct to cause one group to predominate over the
other in most minerals, even though all or nearly all are ordinarily
present (Olson and Adams, 1962). The rare earths are found in a
large number of minerals, only a few of which have been found in
sufficient concentration to be used as ores. The most widely used
source material is monazite, a rare-earth phosphate, that is also an
important ore mineral of thorium (See Thorium section). Bastnae-
site, a rare-earth fluocarbonate that is less common than monazite, is
now being actively mined from a very large deposit at Mountain Pass,
in San Bernardino County.
Commercial monazite commonly contains 55 to 60 percent combined
rare-earth oxides and 3 to 10 percent thorium oxide (Kelly, 1962, p. 5).
Bastnaesite has a slightly higher rare-earth content than does mona-
zite, but contains little or no thorium. Both monazite and bastnaesite
contain predominently cerium group rare earths, but during the
processing of these minerals, notably monazite, there is a recovei*y of
yttrium and the heavy rare earths that has so far met much of the
demand. Increased applications of yttrium and the heavy rare earths
may, however, require other sources, so there is a growing interest in
deposits containing minerals in which yttrium group elements pre-
dominate. Such minerals include xenotime — an yttrium phosphate,
and euxenite — a multiple oxide of yttrium, niobium, and titanium.
Minable deposits of these minerals are uncommon, but xenotime has
been obtained from monazite placers at Aiken, South Carolina, and
euxenite has been recovered on a large scale, primaril}' for its niobium
content, from placers at Bear Valley, Idaho.
The rare-earth industr}' is developed largely around the cerium
group elements obtained from monazite and bastnaesite. Concen-
trates of these minerals containing nearly 2,850 short tons of rare-
earth oxides were apparently processed in the ITnited States in 1968
(Parker, 1965). The rare earths contained in the ore minerals are
converted into a variety of products, including cerium oxide, salts of
MINERAL AND WATER RESOURCES OF CALIFORNIA 351
the elements in varying degrees of purity, and misch metal, which is a
mixture of the rare earths in their metallic state.
For most industrial uses, materials containing several of the rare
earths in partly purified compounds are satisfactory. Products equiv-
alent to about 1,800 tons of rare-earth oxides are used each year in these
bulk applications (Chem. Eng. News, 1965) which include glass pol-
ishes, cores for arc-light carbons, catalysts, and the manufacture of
misch metal which is used for sparking alloys and in metallurgical
applications.
The development of ion exchange techniques for the separation of
rare-earth elements has made high-purity metals and compounds
available at greatly reduced cost and has thus stimulated research as
to applications where their individual properties may be useful. A
small but growing part of the industry is concerned with meeting the
demand for these purified materials, both for further research and for
newly discovered uses, which so far have been largely in the fields of
nuclear energy and electronics. Two of the more promising applica-
tions are the manufacture of synthetic yttrium-iron garnets for elec-
tronic use, and the recently publicized development of new red phos-
phors employing europium-doped yttrium-vanadium compounds for
use in color television tubes (Chem. Eng. News, v. 43, no. 19, 1965).
Other actual and potential uses are discussed by Parker (1965, 1965A)
and Mandle and Mandle (1964) .
The marketing of rare-earth ores is difficult, particularly in small
lots, and prices are generally determined by negotiation between buyer
and seller. The prices paid for imported monazite depend on the
thorium oxide and rare-earth oxide content and have ranged in recent
years between 10 and 20 cents per pound (Parker, 1965) .
OCCUKRENCES IN CALIFORNIA
California contains the free world's largest known concentration
of rare-earth minerals in the Mountain Pass district in San Bernar-
dino County (No. 6). Since the discovery of bastnaesite in the area
in 1949, the district has been intensively studied (Olson and others,
1954) and deposits of rare earths and thorium were found to occur in
a belt about 6 miles long and II/2 miles wide. This belt, which con-
sists of Precambrian metamorphic and igneous rocks, is bomided on
the east and south by alluvium, and on the west and north by major
faults. The metamorphic complex within the belt has been intruded
by potash-rich rocks, considered to be of Precambrian age, that range
from shonkinite through syenite to granite. Dikes of probable Ter-
tiary age are also found in the complex.
Rare-earth minerals, chiefly bastnaesite, occur locally in carbonate-
rich veins and in the very large Sulfide Queen carbonate body that is
now being mined by The Molybdenum Corp. of America. This de-
posit, which is 2,400 feet long and as much as 700 feet wide is estimated
to contain 10 percent rare-earth fluocarbonate minerals, 20 percent
barite, 10 percent quartz and silicate minerals, and 60 percent car-
bonate minerals, chiefly calcite (Olson and others, 1954, p. 29-30).
According to Kruesi and Duker (1965), there are "4 billion pounds
of rare-earth oxides in proven ore with the deposit still not delineated
in depth." The Sulfide Queen carbonate mass as well as the many
smaller carbonate bodies in the area presumably were derived from the
352
MINERAL AND WATER RESOURCES OF CALIFORNIA
same source as the somewhat older potash-rich rocks in the area ; such
carbonate-rich intrusive rocks, or carhonatites^ are relatively micom-
mon, but are of increasing worldwide interest as sources of niobium,
thorium, and the rare earths.
The bastnaesite in the Mountain Pass ore is recovered by flotation
and then is leached with hydrochloric acid to remove remaining ad-
mixed carbonate minerals, giving a product containing 72 percent
rare-earth oxides. By roasting the purified bastnaesite to remove
fluorine and carbonate, the content of rare-earth oxides is raised to
over 90 percent (Parker, 1965). In July, 1965, a new plant was put
in operation at Mountain Pass for the separation of europium and
other individual elements present in the ore (Mining Engineering,
1965).
Although the bastnaesite-bearing carbonatite body at Mountain
Pass is the only rare-earth deposit being mined in California, many
other occurrences of rare-earth minerals are known in the State.
Some of these are shown in figure 66 and are listed in table 38 together
with literature references. These deposits are of two principal types.
Table 38. — Rare-earth mineral occurrences in California
Index
No. on
fig. 66
Locality
Mineralogy and type of deposit
References
1
Little Nell mine
Dean's mine. - _. _ .-
Braimerite in albitite dike
Brannerite in auartz vein
Allanitein pegmatite
AUanite, minor monazite in peg-
matite.
Euxenite, allanite, xenotime(?) in
pegmatites.
Bastnaesite, parisite, monazite,
cerite, sahamalite in carbonatite
and veins.
Monazite in pegmatite . ...
Pabst and Stinson, 1960.
Pabst, 1954.
3
4
Hunter Mountain
Lemon Cove
McAllister, 1956.
D. F. Hewett, oral comm., 1960.
5
6
Kern River area
Mountain Pass area _ _ .
Rainbow Group
Marl Springs area
Hoerner-Ross
MacKevett, 1960.
Olson and others, 1954; Glass,
Evans, Carron, and Hildebrand,
1958.
Walker and others, 1956.
8
9
MonaziteC?) in metasediments
cut by pegmatites and granite.
Betaflte and cyrtolite in pegmatite.
Allanite in granitic detritus
Monazite(?) in shear zones in
granite; also in biotite-rich
layers and pegmatite zones.
Rare-earth minerals in contact
metamorphic rocks.
Allanite in cneiss
Olson and Adams, 1962.
Hewett and Glass. 1953.
10
Roll Prospect-
Walker and others, 1956.
11
Gorman area
Olson and Adams, 1962.
12
Hope prospect
Chesterman and Bowen, 1958;
13
Lokey prospect
Old Woman Springs. _.
Pacoima Canyon
Little Tajunga Canyon.
Gillespie prospect
Lucky Seven and
Birthday No. 4.
Rock Corral area
Steiner prospect
Copper Mountain area.
Alger Creek
Southern Pacific Co., 1964.
D. F. Hewett, oral comm., 1960.
14
15
Brannerite and euxenite in gneiss _
Allanite in pegmatite
Hewett, Stone, and Levine, 1957.
Neuerburg, 1954.
16
17
18
19
20
21
22
Monazite in biotite schist
Monazite in quartz lenses in schist.
Allanite, and monazite dissemi-
nated in biotite-rich pods in
granite.
Allanite, xenotime(?) and mona-
zite(?) in quartz monzonite.
Euxenite, allanite, and mona-
zite at Pomana Tile Quarry
pegmatite.
A lanite(?) and monazite in biotite
schist.
Monazite and allanite in biotite-
rich parts of gneissoid granit*.
Allanite and uranothorite in peg-
matitic zone in gneiss.
Monazite and xenotime in meta-
morpliic rocks and migmatite.
Xenotime, monazite, multiple
oxides in pegmatite.
Xenotime and monazite in peg-
matites.
Monazite in gneiss, associated
chiefly with biotite schist.
Monazite in biotite schist
G. J. Neuerburg, oral comm., 1965.
D. F. Hewett, oral comm., 1960.
Walker and others, 1956.
Moxham and others, 1955; Hewett
and Glass, 1953.
Walker and others, 1956.
Walker and others, 1956.
Hewett and Stone, 1957.
23
Music Valley
Evans, 1964.
24
25
Southern Pacific Silica
Quarry.
Winchester . . .
Patchick, 1960.
Murdoch and Webb, 1956.
26
Desert View _
Walker and others, 1956.
27
Eureka prospect
Pala district
Olson and Adams, 1962.
28
Allanite, monazite in pegmatites..
Murdoch and Webb, 1956.
MINERAL AND WATER RESOURCES OF CALIFORNIA
353
124'
123'
121*
^SOUTHERN
122
,
; s I s K il y o\i
cascaHe N. <J\ I
[[mo U nVa p Nfe,.^^^^?J^
t
..-1..
^
Pli'MAS
-V \ x«1 .1.
Y %. _J-: <f-*^'*5,,!' ^"-'T^ >'' SIERRA .
EXPLANATION
•
Concentrations in veins or
shear zones or in igneous
or metamorphic rocks
O
Concentrations in pegmatites
Concentrations in carbonatite
and re la ted ve ins
+ 3
TUOLIMNE
MARIPOS.y sj
123-sl>:
FranciRflfl
V \ Q^ X,
117'
ONTERF.V n ^:^ > I
//
,n6*
36°-
4-
122*
X
S'.N
I
:.U-^
-K36-
■l
■"^LL'IS '^.\^B.k,r»field,
^"J- OBISPO
^SANTA"0^^
lBARBARaJ '-'Arm
7
^8 N.
P-PAf
y i MOJAVE
W" SAN BfQnARD1S|)2 \
9nESEF^ :^
2 0 y
■ — -f-if
LOS ANCFJ.ES1
Ti
121 •
x_l
150 MILES
>^%
SAN OlE'iO
I vmpeW*c
117'
Figure 66. Rare-earths in California (niunber refers to table 38).
Deposits of the first type are pegmatites. These are commonly dike-
like bodies that range from a few inches to thousands of feet in length.
They are fomid in crystalline rocks and are characterized by lar^e,
but extremely variable, grain size. Most pegmatites are granitic m
composition, having as their dominant minerals quartz, feldspar, and
mica, which are the minerals found in ordinary granite. A large num-
ber of minerals containing rare earths have been found in pegmatites,
but of these monazite and allanite, a silicate of calcium, iron, and the
rare earths, are probably the most common. A notable pegmatite ocur-
rence is the Southern Pacific silica quarry near Nuevo (No. 24), in
which monazite, xenotime, and samarskite have been reported. Peg-
matites, in general, are not an economic source of the rare eaiths as
the small quantity of rare-earth minerals found in any one pegmatite,
354 MINERAL AND WATER RESOURCES OF CALIFORNIA
and the diverse mineralogy commonly represented, make marketing
of these ores difficult or impossible.
Deposits of the second type are segregations of rare-earth minerals
in metamorphic rocks or in biotite-rich zones in igneous rocks. Sev-
eral such deposits were found during the j>eriod of intensive search
for uranium, as all show some degree of anomalous radioactivity due
largelj^ to thorimn. Most commonly, deposits of this type contain
only monazite, but in the southern Music Valley (No. 23) concentra-
tions of xenotime with subordinate monazite are found in biotite-rich
zones in gneiss in a northwest-trending belt about 3 miles wide and 6
miles long (Evans, 1964). An unusual occuiTence of euxenite and
brannerite, the latter a multiple oxide of uranium and titanium con-
taining rare earths, was found in granite gneiss near Old Woman
Springs in San Bernardino County (No. 14).
Brannerite, together Avith gold, AVas found in an albite-rich dike at
the Little Nell mine in Plumas County (No. 1), and with molybdenite
and other sulfides in a quartz vein at Dean's mine in Mono County
(No. 2).
Rare-earth minerals are re^wrted to occur in a contact metamorphic
deposit at the Hope mine in San Bernardino County (No. 12) .
Placer deposits, in which monazite and other heavy minerals have
been concentrated in sands formed by the weathering of igneous and
metamorphic rocks, are the source of rare-earth minerals in many
parts of the world. No important placer deposits of these minerals
appear to have been found so far in California, although minor
amounts of allanite, monazite, xenotime, and euxenite occur locally
in coastal beach sands (Hutton, 1959), and monazite has been re-
ported among the heavy mineral assemblage in the sands of streams
at several localities in the State (Chesterman, 1950; Stinson, 1957).
Many additional deposits of rare-earth minerals undoubtedly re-
main undiscovered in California. This is particularly true of con-
centrations in metamorphic rocks, which easily can be overlooked
unless their generally high anomalous radioactivity is detected. The
recognition of some rare-earth minerals can be facilitated by the use
of a hand spectroscope by which characteristic absorption bands
produced by certain rare-earth elements can be seen when the mineral
is examined in strong white light (Mertie, I960; Adams, 1965).
With the notable exception of the Mountain Pass deposits most of
the rare-earth occurrences in California are at present of unknown
])otential or of mineralogical interest only. An increased demand
for yttrium, or any of the other heavy rare-earth elements, could pos-
sibly make the xenotime-bearing gneiss deposits minable, providing
sufficient tonnage is available for sustained operation.
Selexited Refekences
Adams, J. W., 1965, The visible region absorption spectra of rare-earth min-
erals : Am. Mineralogist, v. 50, p. 356-36G.
Chemical and Engineering Xews, 1965, Rare earths : Chem. and Eng. News, v.
43, no. 19, p. 7S-92.
Chesterman, C. W.. 1950, Uranium, thorium, and rare-earth elements, in Min-
eral commodities of California : California State Div. Mines Bull. 156, p.
361-363.
MINERAL AND WATER RESOURCES OF CALIFORNIA 355
Chesterman, C. W., and Bowen, O. E., Jr., 1958, Fluoborite from San Bernardino
County, California [abs.] : Geol. Soc. America Bull. v. 69, no. 12, p. 1678-1679.
Evans, J. R., 1964, Xenotime mineralization in the southern Music Valley area.
Riverside County, California : California State Div. Mines Spec. Rept. 79,
24 p.
Glass, J. J., Evans, H. T., Jr., Carron, M. K., and Hildebrand, F. A., 1958, Cerite
from Mountain Pass, San Bernardino County, California : Am. Mineralo^st,
V. 43, p. 460-475.
Hewett, D. P., and Glass, J. J., 1953, Two uranium-bearing i)egmatite bodies in
San Bernardino County, California : Am. Mineralogist, v. 38, p. 1040-1050.
Hewett, D. F., and Stone, Jerome, 1957, Uranothorite near Forest Home, San
Bernardino County, California : Am. Mineralogist, v. 42, p. 104-107.
Hewett, D. P., Stone, Jerome, and Levine, Harry, 1957, Brannerite from San
Bernardino County, California : Am. Mineralogist, v. 42, p. 30-38.
Hutton, C. O., 1959, Mineralogy of beach sands between Half moon and Monterey
Bays, California : California State Div. Mines Spec. Rept. 59, 32 p.
Kelly, F. J., 1962, Technological and economic problems of rare-earth metal and
thorium resources in Colorado, New Mexico, and Wyoming: U.S. Bur. Mines
Inf. Oirc. 8.124, 38 p.
Kruesi, P. R. and Duker, George, 1965, Production of rare-earth chloride from
bastnasite : Jour. Metals, v. 17, no. 8, p. 847-849.
McAllister, J. F., 1955, Geology of mineral deposits in the Ubehebe Peak quad-
rangle, Inyo County, California : California State Div. Mines Spec. Rept. 42,
63 p.
MacKevett, E. M. Jr., 1960, Geology and ore deposits of the Kern River uranium
area, California : U.S. Geol. Survey Bull. 1,087-F, p. 169-222.
Mandle, R. M., and Mandle, H. H., 1964, Uses and applications, in Eyring, Leroy,
ed.. Progress in the science and technology of the rare earths, v. 1 ; New York.
The Macmillan Co., p. 416-500.
Mertie, J. B., Jr., 1960, Monazite and related minerals, in Gillson, J. L., ed.,
Industrial minerals and rocks, 3d ed. : New York, Am. Inst. Mining Metall.
Petroleum Engineers, p. 623-629.
Mining Engineering, 1965, The rare earth boom, Molycorp. starts new plant:
Mining Eng., v. 17, no. 8, p. 14-15.
Moxham, R. M., Walker, G. W., and Baumgardner, L. H., 1955, Geologic and air-
borne radioactivity studies in the Rock Corral area, San Bernardino Coiuity,
California : U.S. Geol. Survey Bull. 1021-C, p. 109-12.5.
Murdoch, Joseph, and Webb, R. W., 1956, Minerals of California : California State
Div. Mines Bull. 173, 452 p.
Neuerburg. G. J., 1954, Allanite pegmatite, San Gabriel Mountains, Los Angeles
County, California : Am. Mineralogist, v. 39, p. 831-834.
Olson, J. C, Shawe, D. R., Pray, L. C, and Sharp, W. N., 1954, Rare-earth mineral
deposits of the Moimtain Pass district, San Bernardino County, California :
U.S. Geol. Survey Prof. Paper 261, 75 p.
Olson, J. C, and Adams, J. W., 1962, Thorium and rare earths in the United
States : U.S. Geol. Survey Mineral Inv. Resource Map MR-28.
Pabst, Adolph, 1954, Brannerite from California : Am. Mineralogist, v. 39,
p. 109-117.
Pabst, Adolph, and Stinson, M. C, 1960, Brannerite with gold from Plumas
County, California [abs.] : Geol. Soc. America Bull., v. 71, p. 2,071.
Parker, J. G., 1965, Rare-earth elements, in Mineral facts and problems, 1965 etl. :
U.S. Bur. Mines Bull. 630 (preprint) , 16 p.
, 1965A, Yttrium, in Mineral facts and problems, 1965 ed. : U.S. Bur. Mines
Bull. 630, (preprint) , 8 p.
Patchick, P. F.. 1960, A rare-earth pegmatite near Nuevo, California : Rocks and
Minerals, v. 35, nos. 7-8, p. 323-327.
Southern Pacific Company, 1964. Minerals for industry. Southern California, v. 3 :
San Francisco, Southern Pacific Co., 242 p.
Stinson, M. C, 1957, Black sands, in Mineral commodities of California : Call
fornia State Div. Mines Bull. 176, p. 83-85.
U.S. Bureau of Mines, 1965, Rare-earth elements : U.S. Bur. Mines Mineral
Trade Notes, v. 60, no. 3, p. 22-23.
Walker, G. W., Lovering, T. G., and Stephens, H. G., 1956, Radioactive deposits
in California : California State Div. Mines Spec. Rept. 49, 38 p.
356
MINERAL AND WATER RESOURCES OF CALIFORNIA
SALT
(By G. I. Smith, U.S. Geological Survey, Menlo Park, Calif.)
Salt is one of the basic commodities of man. For centuries it has
been used ahnost universally as an element of diet and as preserva-
tive, although it was probably unobtainable to most primitive tribes
that were remote from oceans, saline lakes, and salt springs. How-
ever, as trade routes became established, and as man began to cook
his food, it became a virtual necessity to most groups and an important
item of trade. Because of its importance, some cultures endowed salt
with religious significance, others affixed a tax to it, and still others
used it as a form of currency.
The earliest recorded use of salt in California was by the Indians
w^ho occupied this area for thousands of years before the arrival of
white settlers. Their supply came chiefly from salty grass, seaweed,
saline watei-s, and solid deposits. Virtually every tribe in the State
used one of these forms of salt routinely, although those tribes that
lived to the north apparently used none (Heizer, 1958).
Most of the early white settlers in California lived near its coast
or along the edges of its bays, and they obtained salt from tide pools.
Salt was first "manufactured" in 1856 by a settler who built levees
around tide pools along the edge of San Francisco Bay to improve
their capacity. This was the begimiing of the salt industry in Cali-
fornia, and, as indicated by the data in table 39 and figure 67, it grew
rapidly from that time on.
Table 39. — Estimated production capacity, sea water-evaporation plants in
California
Company
Source of sea water
No. on
flg. 67
Areas of
crystalliza-
tion ponds
(acres)
Estimated
production
capacity '
(tons per
year)
Leslie Salt Co
San Pablo Bay
1
3,4,5
9
8
3
6
2 180
<2,300
MOO
5 24
57
3 100, 000
Do
San Francisco Bay
San Diego Bay
1, 265, 000
Western Salt Co
55,000
Do
Newport Bay -_.
4,500
Oliver Bros. Salt Co
San Francisco Bay
Monterey Bay - - --
13,200
Western Salt Co
3,800
Total (rounded)
1, 450, 000
1 Except as indicated, estimated from crystallization pond area, using factor of 550 tons per year per acre
(See, 1960, p. 100).
- Approximate, estimated from data on production in Ver Planck, 1958, p. 43, and factor of 550 tons per
acre per year (see 1960, p. 100) .
3 Ver Planck, 1958, p. 43.
* Approximate, estimated from U.S.G.S. topographic maps.
5 Ver Planck, 1958, chap. 2.
A few years later, in 1862, the Comstock Lode was discovered in
Nevada, and, because salt was one of the raw materials needed to
process the ores, a major increase in production from the San Francisco
Bay area took place. The steady population increase in California
during and after this period further increased the demand for salt
for table use and food curing. Because of quality differences, imports
supplied most of these needs until well into the 1870's, but by 1880, the
finality of domestic evaporated salt had improved to a point where
imports ceased, and salt began to be exported. By this time, many
small plants had been developed around San Francisco Bay and else-
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANATION
357
1 0
'2"* 123' 122- 121- 120
"• (■ S 1 S K l| Y 0\U/-^ 'S.
iKh,AMAT>5( jPn O 1 ; I
<^
,-5,'> r -v — V \ \ ^, ;ir
4oi
%.
Production f r om
eva pora t i on of sea water
Production from evaporation
of other sa I i ne wa te r s
,f/oduction from solid salt
Present pr oduc t i on
~\ US' from area
IO\ -!-38'
I ^ N\ / TUOLUMNE
^ ^ -VvJMARIPOSA^ \\
R ^ \\ ^FKESN<^ ^ N\ INYdXS \
.."J^^
^5\
G^^c. X""
^
^
\
<^.
MOJAVE
,\
C
vJi
v^ *-' OBISPO '
5'^°+ f'-ivSANTA-O^J 1/^' , ^^^. BERNARDINO
^~\. 2 2
BARBARA! ' V,
— ' T
,\L0S ANGELESi
' V
\
ir'
SIDE
160 MILfS
_J
^\ —
115*
117-
Figure 6|7. Salt deposits in California (numbers refer to table 40).
where in the State. Around 1900, there were about 20 plants in the
San Francisco Bay area, and solar evaporation plants were being
started in the San Pedro and San Diego Bay areas. Over the next
40 years, a series of company mergers in the San Francisco area took
place, and, by 1940, only three companies remained, the Leslie Salt
Co., the Oliver Bros. Salt Co. (started in 1937) , and the American Salt
Co. (Ver Planck, 1958). Of these, only the first two are still in
production.
Production of salt from inland sources began in the 1880's and be-
came significant in the early 1900's. Some of these deposits consisted
of brine, others of solid salt. Almost all of these have had a history
of intermittent production as a result of purification difficulties and
high transportation costs. Four deposits are still in production, Koehn
Lake, Searles Lake, Danby Lake, and Bristol Lake.
358 MINERAL AND WATER RESOURCES OF CALIFORNIA
The geologic occurrences of salt are varied. Besides the almost
iinlimiteu quantities available from the oceans, it is found in the
United States as rock salt and brines in marine sedimentary deposits
of all ages and in nonmarine deposits of late Cenozoic age. The
major deposits of rock salt in the United States are of marine origin.
Most current production comes from those of Silurian age in the New
York-Pennsylvania-Ohio-Michigan area, and those found as salt
domes in the Gulf Coast area. Other large marine deposits are
of Permian age in the Kansas-Oklahoma-Texas- New Mexico area ; of
Devonian, Mississippian, Permian, and Jurassic ages in the North
Dakota-South Dakota-Montana area; of Pennsylvanian age along the
Utah-Colorado boundary area ; and of Permian age along the Arizona-
New Mexico boundary area (Lang, 1957; Landes, 1960; Bersticker,
1963). Extensive areas underlain by subsurface brines also occur in
and around West Virginia and southeastern Illinois. Large non-
marine deposits of Pliocene age are known in southeastern Nevada
(Mannion, 1963). Smaller deposits are found in the Western United
States in the form of brine wells and springs, outcrops, and saline
lakes or salt flats.
Many of these smaller deposits occur in California. Brine wells
and springs having diverse geologic settings occur in the northern part
of the State; salt outcrops are found in an area of deformed late
Cenozoic (continental) nonmarine sediments at the south end of Death
Valley ; saline lakes and salt flats occur in many of the closed basins of
the Great Basin, Mojave Desert, and Salton Trough provinces.
The deposits in closed basins are of Quaternary age and consist of
saline lake^ or dry playas underlain by saline brines. They ai'e the
results of climatic fluctuations that took place during the Quaternary
Period; the wetter periods accelerated the introduction of dissolved
saline material into these basins, and the drier periods caused these ac-
cumulations to precipitate on the floor of the lake. The compositions
of these deposits are variable, though, because each basin was the site
of a unique set of controls; among the significant compositional con-
trols were the lithologies of the rocks in the drainage area, the abun-
dance and character of the mineral springs, the hydrologic history of
the waters entering the valley, and the character of successive climatic
cycles. This variability has caused many of the commercial failures
on such deposits because the extraction and purifying teclmiques used
successfully on one cannot be adapted easily to another. The com-
positions of deposits precipitated from sea water were affected by
some of these variables, but the chemical makeup of the starting water
was much more uniform.
Li 1963, over 100 million tons of salt was produced throughout the
world. The United States produced over 30 million tons of this total,
with a value of about $185,000,000. About 83 percent of this ijroduc-
tion came from plants in Louisiana, Texas, New York, Michigan, and
Ohio. Eleven percent came from smaller plants in Virginia, West
Virginia, Alabama, North Dakota, Oklahoma, Kansas, Colorjxdo,
Utah, New Mexico, Nevada, and Hawaii. California provided a little
less than 6 percent (Kerns 1964) .
Production of salt in California during 1963 was a little over 1,700,-
000 tons. Most of this came from solar evaporation plants along the
coast. An estimate of the production capacity of these coastal plants
(table 40) suggests that they may have provided as much as 85 percent
MINERAL AND WATER RESOURCES OF CALIFORNIA
359
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360 MINERAL AND WATER RESOURCES OF CALIFORNIA
of the State's total and that inland sources may have provided only
about 15 percent. Over 90 percent of the coastal production capacity
lies in the San Francisco Bay area.
This predominance of salt production by means of solar evaporation
is in marked contrast to the sources utilized throughout the rest of the
United States; about 60 percent of national production comes from
solution mining of underground deposits, 35 percent comes from under-
ground mining of such deposits, and 5 percent comes from solar evap-
oration of sea and lake brines (MacMillan, 1960). It is evident,
therefore, that California, with less than 6 percent of national produc-
tion, has contributed most of the Nation's salt produced by solar
evaporation.
The large consumers of salt in the United States are chemical in-
dustries. In 1963, manufacturers of chlorine and its coproduct sodium
hydroxide consumed 39 percent of national production, manufacturers
of sodium carbonate by the Solvay process consumed 21 percent, and
manufacturers of other industrial chemicals consumed 2 percent; table
and other household uses account for less than 3 percent (Kerns, 1964) .
Because of its geographic position and industrial balance, California's
production is used somewhat differently ; a slightly higher percentage
is used for chlorine-sodium hydroxide production, none is used for
sodium carbonate production, about the same percentage is used for
other chemicals, and distinctly higher percentages are used for water
treatment and refrigeration (Ver Planck, 1958, p. 95; 1957, p. 490).
Because salt is so plentiful and widespread, it is a relatively cheap
substance. In 1963, the average value in bulk lots of solar-evaporated
salt was quoted as $5.74 per ton; rock salt was quoted at $6.19 per ton
(Kerns, 1964). However, the costs of transportation add substan-
tially to the delivered price. For example, rail freight rates for salt
in 1954 from salt plants near Newark (on the southeast side of San
Francisco Bay) were $1.42 per ton to San Francisco, $7.83 to Los
Angeles, and $8.86 to Seattle; rates from Searles Lake were $10.64
to San Francisco, $4.26 to Los Angeles, and $16.83 to Seattle (Ver
Planck, 1958). These data make it evident that transportation costs
account for over half the delivered price to all but the closest major
markets.
Transportation by ship, though, is relatively cheap; for example,
salt is transported from Louisiana to east coast markets for $12 per
ton by sea train compared with $18 per ton by rail. In 1963, Califor-
nia imported nearly 50,000 tons of salt by ship from foreign countries,
most of which probably came from Mexico (Kerns, 1964). New
sources being developed in Mexico and other central and South Ameri-
can countries are likely to increase this imported tomiage.
The future supplies of salt to the United States and California are
theoretically almost unlimited. Actually, though, an unlimited sup-
ply is of little use to those industries that require it unless the price
remains low. Because of transportation costs, this means that salt
production facilities must remain close to those industries. The bulk
of California industry of this type depends on salt from solar evapora-
tion plants along the coast, and in the future, with increasing popu-
lation pressures, these sources of supply may be threatened. At pres-
ent, thousands of acres of evaporating ponds in the San Francisco Bay
MINERAL AND WATER RESOURCES OF CALIFORNIA 361
area are being reclaimed for housing developments. If population
pressures in California continue, this alternative use of such land may
become more attractive to its ownei-s, both around San Francisco Bay
and in other areas — most of which also lie on reclaimable land near
large and expanding population centers.
Thus, the long-term prospects for a continued supply of salt from
these solar evaporation plants is uncertain. To maintain the present
balance of supply and demand, it appears that unless reclamation of
such land for real estate uses is found to be impractical, population
pressures must decrease. Otherwise, the cost of salt to the nearby
industrial users will have to mcrease, either because higher prices
would be needed to justify production from these lands or because
more distant suppliers would be used. The supplies of salt from these
more distant areas are probably adequate, but the costs of transporta-
tion are likely to be higher. Transportation by ship from the gulf
coast or foreign countries might minimize this added cost, but the
economic pressure will encourage salt-consuming industries to locate
nearer those sources in the future.
Selected Refe^rences
Bersticker, A. C, ed., 1963, Symposium on salt: Cleveland, The Northern Ohio
Geol. Soc, Inc., 661 p.
Heizer, R. F., 1958, Salt in California Indian culture, m Ver Planck, W. E., Salt
in California : California Div. Mines Bidl. 175, p. 103-104.
Kerns, W. H.. 1964, Salt: U.S. Bur. Mines, Minerals Yearbook, 1963, v. 1, p.
953-966.
Landes, K. K., 1960, Salt deposits of the United States, Chap. 5 of Kaufmann,
D. W., ed., Sodium chloride — The production and properties of salt and brine :
New York, Reinhold Pub. Corp., p. 70-95.
Lang, W. B., 1957, Annotated bibliography and index map of salt deposits in the
United States: U.S. Geol. Survey Bull. 1,019-J, p. 71.5-753.
MacMillan, R. T., 1960, Salt, in Industrial minerals and rocks: New York, Am.
Inst. Mining Metall. Petroleum Engineers, p. 713-731.
Mannion, L. E.. 1963, Virgin Valley salt deposits, Clark County, Nevada, in
Bersticker, A. C, ed.. Symposium on salt : Cleveland, The Northern Ohio Geol.
Soc, Inc., p. 166-175.
See, D. S.. 1960, Solar salt, Chap. 6 of Kaufmann, D. W., ed., Sodium chloride —
The production and proi>erties of salt and brine : New York, Reinhold Pub.
Corp., p. 96-108.
Ver Planck, W. E., 1957, Salt, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 483-494.
— , 1958, Salt in California : California Div. Mines Bull. 175, 168 p.
SAND AND GRAVEL
(By H. B. Goldman, California Division of Mines and Geology, San Francisco,
Calif.)
California's economic and population growth has been paralleled
by the growtli of one of its leading nonmetallic commodities — sand and
gravel. The continued influx of population with resulting demands
for homes, industrial buildings, highways, and public works proj-
ects has given impetus to this valuable industry. California has been
the leading state in the nation since 1942 in sand and gravel produc-
tion, and, within the State, that industry is exceeded only by produc-
tion of petroleum products and cement.
er'-iei o— ©6— pt. i 24
362 MINERAL AND WATER RESOURCES OF CALIFORNIA
In commercial usage "sand" applies to rock or mineral fragments
ranging in size from three-thousandths of an inch to a quarter of an
inch. "Gravel" consists of rock and mineral fragments larger than a
quarter of an inch ranging up to 8/2 inch maximum size. Approxi-
mately nine-tenths of the State's output is used as aggregate in mix-
tures of either portland cement or asphaltic compounds for use in
construction or road building. The remaining tenth is special sand,
mostly used in glass making, sandblasting, filters, and foundry proc-
esses.
The building industry uses sand and gravel as aggregate in portland
cement concrete; the paving industry uses sand and gravel in both
asphaltic mixtures and portland cement concrete. Aggregate is com-
monly designated as the inert fragmental material which is bound into
a conglomeratic mass by cementing materials such as portland cement,
asphalt, or gypsum plaster.
The principal markets for most commercial producers are within
areas of greatest population density. Large volumes of aggregate
are also used in public works and hi^hwa}^ construction throughout
the entire State. The present economic limit to the distance sand and
gravel can be hauled differs through out the State; the maximum
haul is about 40 miles. Little sand and gravel is sent out of the State
except for a few producers near the State border.
Geologic Occurrence
In California, sand and gravel is obtained commercially from rock
units of many types and ages. Quaternary stream deposits in chan-
nels, floodplains, terraces, and alluvial fans; and Recent beach and
dune sands are the common sources. In some areas in California, sand
and gravel is obtained from pre-Quaternaiy formations.
Stream deposits
The bulk of California's aggregate is obtained from the natural sand
and gravel in stream deposits. California's rugged mountains are
drained by streams which transport, in flood stage, huge volumes of
sand and gravel which is deposited in channels, floodplains, and
terraces. These deposits are the most favorable sources of aggregates
for many reasons. Most source streams are dry a large part of the
year, most of the deposits are easily accessible, and mining operations
are commonly relatively simple. In some streams, excavated material
is replenished during flood stage so that decrease in reserve is slight.
The sand and gravel in stream deposits are most suitable for aggre-
gate, because the natural abrasive action of stream transport grinds
up and removes soft, weak rocks, and concentrates the hard and firm
particles. Streams also exercise a sorting action so that the sand and
gravel are often obtained in the size gradations necessary for aggre-
gate. Individual particles inidergo some degree of rounding and
range from subrounded to very well roimded. Rounding is desirable
in aggregate for portland cement concrete work, as rounded particles
give a more workable mix with less cement and care than concrete
made with angular particles.
In spite of the advantages, some stream deposits are not exj^loited
due to such economic factors as inaccessibility, excessiA'e distance to
MINERAL AND WATER RESOURCES OF CALIFORNIA 363
market, insufficient tonnage of materials available, and restrictive
civic legislation. In addition, some deposits are unsuitable beause
they contain harmful ingredients such as physically unsound or chem-
ically reactive rocks. The nature of the material in a stream bed is
determined by the nature of the source rocks within its drainage area.
The different geologic formations drained by the stream contribute
many varieties of rock types which show a wide range in chemical
composition, physical soundness, and degree of weathering. Thus,
there is danger of encountering unsomid or chemically reactive rock in
a deposit if such rocks occur anywhere within the drainage basin.
Some thick deposits may contain severely decomposed material at
shallow depths beneath seemingly fresh and durable materials. In
some older stream deposits, such as stream terraces, undesirable coat-
ings may be present on the grains, or the materials may be partly
decomposed.
Alluvial fan deposits
Alluvial fan deposits also are widely exploited for aggi-egate. An
alluvial fan is a gently sloping fan-shaped mass of loose rock material
deposited at the mouth of a canyon where a stream leaves the moun-
tains and enters an adjacent plain. Fan deposits ordinarily contain
lenticular beds or tongues of poorly sorted sand and gravel interbedded
with varying proportions of silt and clay. Suitable aggregate is
obtained from these deposits in areas where excessive amounts of clay
are not present.
Beach and dune sand deposits
About two percent of California's total output of sand and gravel
is produced from beach and dune deposits. The deposits consist
almost entirely of sand, which is used as concrete and plaster sand, or
as a specialty sand.
Pre-Quatemary formations
Pre-Quaternary formations, particularly partly consolidated,
poorly cemented marine sedimentary beds of sandstone and conglom-
erate, also are sources of aggregate. Most formations of this nature
are inaccessible, have heavy overburdens, are too well cemented, or
contain too much clayey material to be economically processed for
aggregate through normal washing and screening operations.
History of Production
Records of sand and gravel production in California date back
to 1893. In 61 years, from 1893-1964, almost two billion tons of sand
and gravel valued at about 1.8 billion dollars were produced in the
State. In the ten years from 1954-1964, about one billion tons were
produced (fig. 68) . Thus, more than half of the total recorded produc-
tion for 71 years was produced since 1954. Sand and gravel produc-
tion in Calffornia has constantly risen since 1900, with minor reces-
sions during post -World War I years and ih& depression years of the
1930's. Since 1942, California's production has risen from 28 million
tons valued at 15 million dollars to the 112,995,000 tons, valued at
$129,333,000, produced in 1964.
364
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA 365
Occurrences in California
Usable stream deposits occur throughout the State (tig. 69 and table
4:1), and the nortliern one-third of the State contains large resources
of sand and gravel. Under present economic conditions, only the
deposits nearest to centers of population are of commercial value.
In northwestern California, deposits along the Smitli Kiver supply
the Crescent City area, Del Norte County, and deposits along the Mad
and Eel Rivers supply the Eureka area, Humboldt County. In the
Sacramento Valley, deposits along the Sacramento Eiver, and its tribu-
tary creeks and rivers, provide sand and gravel aggregate for con-
sumption at Redding, Shasta County; Red Blutf, Tehama County;
and Chico, Butte County. On ^he west side of the Sacramento Valley,
stream deposits along Cache Creek provide aggregate for the Wood-
land area, Yolo County. On the east side of the Sacramento Valley,
deposits are exploited along Dry Creek and Butte Creek, near Oroville,
Butte County ; the Yuba River, near Marysville ; the American River,
near Sacramento; and the Mokelumne River, near Clements, San
Joaquin County.
In central California, deposits along the Russian River yield sand
and gravel near Ukiah, Mendocino County; and Healdsburg, Sonoma
County. The large tonnages of sand and gravel consumed in the San
Francisco Bay area are obtained mainly from shallow alluvial cone
deposits of ancestral Alameda Creek in the Niles-Centerville area, and
from valley-fill alluvium along Arroyo del Valle and Arroyo Mocho
in the Livermore-Pleasanton area. Other stream deposits that supply
a portion of the San Francisco Bay area market are located along
Sunol Creek, Alameda County and Coyote, Guadalupe, and Uvas
Creeks near San Jose, Santa Clara County.
In the San Joaquin Valley, the principal stream deposits of sand
and gravel occur along the San Joaquin River and its tributaries. On
the east side of the valley, active deposits occur along the Stanislaus
River near Riverbank, Stanislaus County; the Tuolumne River east
of Modesto, Tuolumne County ; the Merced River near Cressey, Merced
County ; the Kings River near Sanger; the San Joaquin River between
Herndon and Friant, Fresno County; the Kaweah and Tule Rivers
near Porterville, Tulare County ; and the Kern River near Bakersfield,
Kern County. Few stream deposits are worked on the west side of
the valley, the main ones being along Orestimba Creek near Newman,
Stanislaus County ; Los Banos Creek near Los Banos, Merced County ;
and Corral Hollow Creek near Tracy.
In southern California, stream bed and alluvial fan deposits yield
most of the sand and gravel aggregate for the principal consuming
area, the Los Angeles area. Tujunga Creek in the San Fernando
Valley, about 15 miles northwest of Los Angeles, and the San Gabriel
River, about 15 miles east of Los Angeles are the principal sources.
Stream-laid deposits along the lower reaches of the Santa Clara
River provide sand and gravel for use in Ventura and Santa Paula,
Ventura County. The Sisquoc River provides aggregate for the Santa
Maria area. The Santa Ana River and its tributary, Lytle Creek are
the principal sources of sand and gravel for San Bernardino, San
Bernardino County and Riverside, Riverside County.
366
MINERAL AND WATER RESOURCES OF CALIFORNIA
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368
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANAT I ON
Depos i t
Figure 69. Major sand and gravel deposits in California (number r.efer to
table 41).
Alluvial fans are the principal sources of sand and gravel for com-
munities of Barstow and Victorville in San Bernardino County, and
Indio and Palm Springs in Riverside County,
Several geologically older formations also provide significant
amounts of aggregate. The Pliocene to Pleistocene Kern River For-
mation is mined near Bakersfield in Kern County ; a thriving industry
near San Diego, San Diego County is based upon the Eocene Poway
Conglomerate; the Pleistocene Victor Formation is an important
source for Sacramento, Sacramento County; the Pliocene and Pleis-
tocene Santa Clara Formation is worked near San Jose in Santa Clara
County ; and the ancient beach deposits along the Salton Sea provide
material for the Imperial Valley at the southern end of the State.
MINERAL AND WATER RESOURCES OF CALIFORNIA 369
Miocene sandstones are important sources of concrete sands near Fel-
ton, Santa Citiz County, and Torrance in Los Angeles County.
Minor proportions of the beach and dune sand obtained in the
Monterey Bay area, Monterey County are used for plaster and concrete
sand, in addition to its prime use as a specialty sand.
Resource Potentl\l
The market for sand and gravel will continue to expand as Cali-
fornia continues its remarkable growth. However, there are no un-
discovered deposits near the metropolitan areas that can be developed
to meet the demand. Indeed, the State faces depletion of its major
sources within the next three decades unless sand and gravel deposits
can be set aside as natural resource zones for future use.
Selected References
California Division of Highways, 1960, California standard specifications : State
of California, Div. Highways, 445 p.
Goldman, H. B., 1956, Sand and Gravel for concrete aggregate : California Jour.
Mines and Geology, v. 52, no. 1, p. 79-104.
, 1961, Sand and gravel in California — an inventory of deposits. Part A —
Northern California: California Div. Mines, Bull. 180-A, pt. I, 38 p.
-, 1964, Sand and gravel in California — an inventory of deposits, Part B-
Central California : California Div. Mines and Geology Bull. 180-B, pt II, 58 p.
Pit and Quarry Handbook, annual publication of Pit and Quarry Publications,
Inc., Chicago, 111.
U.S. Army, Corps of Engineers, 1949, Handbook for concrete and cement.
U.S. Bureau of Reclamation, 1963, Concrete Manual, Denver, Colo., 7th ed.
U.S. Bureau of Mines Minerals Yearbooks [Sand and Gravel].
SANDS, SPECIALTY
(By H. B. Goldman, California Division of Mines and Geology, San Francisco,
Calif.)
In 1964, California produced 1,482,000 tons of specialty sands
valued at $6,051,000. About 65 percent of the specialty sand tonnage
was used in glass making, 1-3 percent for sandblasting, 6 percent for
grinding and polishing, 4 percent for engine sand, and 12 percent for
other specialty uses.
The special sands used in California are obtained mostly at locali-
ties within the State and consist largely of material from Recent beach
and dune deposits and early Tertiary sandstones.
Nature of Specialty Sands
The term "specialty sand" (or "sj^ecial sand*') is applied to sand
used for purposes otlier than for aggregate, ballast, or fill. Specialty
sands generally have rigid physical and chemical specifications, and
are used in much smaller quantities than ordinary sand. Some spe-
cialty sands include particles of gravel size (larger than a quarter of
an inch).
Most specialty sands are obtained from the purest available sand
deposits that can be economically worked. A high content of quartz
makes the sand physically durable and chemically inert, and also pro-
vides silica as an ingredient of glass and soluble silicates.
370 MINERAL AND WATER RESOURCES OF CALIFORNIA
For most uses, the pliysical properties of specialty sands are more
important than chemical pr()i)erties. The chemical composition is
held to rigid specifications only in the production of glass and soluble
silicates. For use in sandblasting, hardness and durability are the
essential characteristics; in others, such as filter media, close size
grading is essential.
Clay is generally undesirable, mainly because it coats sand grains
and interferes with the usefulness of sand. Only in naturally bonded
foundry sands is clay a desired admixture. Both clay and iron-
bearing minerals constitute chemical im})urities in sands for use in
the manufacture of glass and soluble silicates.
Sand from most specialty sand deposits can be used in several ways.
A single deposit, for example, could yield sand suitable for sandblast-
ing sand, engine sand, or foundry sand. Sands from some deposits
are especially suited to a single use, and hence command relatively high
prices. The purest quartz sands are most prized for use in glass.
Some clay-rich sands are used only as naturally bonded foundry sands,
and "ganister".
Uses such as glass and soluble silicate manufacture require sand so
clean that rigorous cleaning and beneficiation ordinarily are required.
Sand to be used for less exacting purposes, such as for sandblasting
and engine sand, commonly require little or no washing. Sand from
some deposits is clean enough and of the right size for these uses with-
out any processing.
Although nearly all clay-free special sand is suited for use as aggre-
gate sand (concrete and plaster sand), the sands of higher quality are
more valued as specialty sands.
Occurrences in California
In California, as well as elsewhere, deposits from which specialty
sands can be mined are much less common than the deposits that con-
tain aggregate-grade material. Most of the specialty sand is obtained
from Recent beach and dune de])osiis, and from Tertiary sedimentary
rocks as shown in figure 70 and table 42; relatively minor quantities
of Recent alluvial sand are processed for specialty uses.
Recent beach and dune sands along the Pacific Ocean, in general,
contain a lo^^er proportion of quartz, and a higher proportion of
feldspar, dark mineral grains, and rock fragments than the Tertiary
sandstones that are mined for high-silica specialty sands. Beach
sands, therefore, are used mostly for sandblasting, engine, and foun-
dry sand, and for minor applications that do not require high-purity
silica sand. Most beach sand deposits are measurable in many millions
of tons, have little or no overburden, and can be mined inexpensively.
Most of the beach and dune sand that is mined in California for
specialty uses is obtained from two areas in Monterey County; one
is immediately southwest of Pacific Grove, and the other is along the
shore of Monterey Bay, north of Montere3\ The deposits southwest
of Pacific Grove are unlike other beach sand deposits in California
because of their uncommonly white color, and general lack of clay,
iron-bearing minerals, and rock fragments. They consist of about 53
percent quartz grains; 46.5 percent feldspar, and 0.5 percent other
minerals, including biotite, ilmenite, garnet, zircon, and monazite
MINERAL AND WATER RESOURCES OF CALIFORNIA 371
(Valentine, P. C, oral communication, 1954) . Nearly all sand grains
pass a 20-mesli sieve, and 1 or 2 percent pass a 100-mesli sieve.
The east shore of Monterey Bay is formed entirely of dune sands,
which consist largely of feldspar grains and have appreciably higher
iron content than the Pacific Grove sand, both as ferromagnesian
minerals and as ferruginous coatings on the quartz and feldspar
grains. This sand is sold mainlj' for use as sandblasting and foundry
sand, and for plaster and concrete sand.
At Oceano Beach, San Luis Obispo County, a dune area several
square miles in extent yields clean feldspathic sand that is unusually
fine grained, and closely graded in grain size ; about 90 percent of the
grains are retained on the 100- and 140-mesh sieves. This sand is sold
unprocessed, mainly for use as foundry sand.
At El Segundo, Los Angeles County, ordinary feldspathic dune
sand is obtained for use as foundry sand.
Most of the beach and dune sands in northern California contain
large proportions of dark mineral grains and dark rock fragments,
and have been much less extensively used as specialty sands than those
from Monterey Bay and southward.
In 1963 all the specialty sand recovered from the beaches of Cali-
fornia was obtained in seven operations; two at Pacific Grove; three
on Monterey Bay ; one at Oceano Beach ; and one at El Segimdo.
In California, some of the highest quality silica sands are obtained
from sedimentary sandstone formations of early Tertiary age. Al-
though less pure than the silica sands mined in Illinois and Missouri,
they form the principal source of supply for the glass industry of
California. Tertiary deposits that have yielded sand for specialty
uses include Paleocene def»osits south of Corona, Eiverside County,
and in the Trabuco Canyon area. Orange County; and Eocene de-
posits near lone, Amador County; Oceanside, San Diego County;
Tesla, Alameda County; and in the Nortonville-Somersville and
Brentwood areas, Contra Costa County.
These deposits consist essentially of quartz grains and clay, with a
low percentage of partly decomposed feldspar, and very small pro-
portions of heavy, resistant minerals such as garnet, epidote, zircon,
magnetite, and ilmenite. They are exposed in belts that range from
several thousand feet to several miles long, are ordinarily about 25 to
200 feet thick, and dip gently to moderately. They have been mined
mostly by open-pit methods. If it is to be used for glass sand, the
mined material requires beneficiation to remove clay and iron-bearing
minerals. The high-quality clay recovered from the beneficiation of
these sands in the lone and Trabuco Canyon areas is valued for
ceramic uses. Sand from these deposits also is used, with relatively
minor treatment, for f oundi-y sand and less common uses.
In 1963, six operations were active in these high-silica sandstones
of early Tertiary age. One was at lone, Amador County; one near
Corona, Riverside County;. two in the Trabuco Canyon area, Orange
County ; one near Oceanside, San Diego County ; and one near Anti-
och, Contra Costa County. Those near lone, Corona, and Oceanside
produced sand mainly for use in glass ; those near Trabuco Canyon
and Antioch mostly produced foundry sand.
Post-Eocene Tertiary sandstones are very widespread and abundant
in California, but they have not been extensively mined as sources
372
MINERAL AND WATER RESOURCES OF CALIFORNIA
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MINERAL AND WATER RESOURCES OF CALIFORNIA
373
EXPLANAT ION
RECENT BEACH AND DUNE SANDS
Monterey Bay Beach and Dunes
Monterey Peninsula Dunes
Oceano Dunes
El Segundo Dunes
RECENT ALLUVIUM
Bear River Stream Bed
Valley Floor Al 1 u v ium-Torr ance
TERT lARY SANDSTONE
7 . I one Forma t i on
8. Te s 1 a Formation
9. Domengine Formation
0. Silverado Formation
11. Tejon Formation
12. Pleistocene unnamed
118'
i\MONO\ — |— 38*
x
Figure 70. Specialty sand deposits in California.
of specialty sands. Their characteristically high-feldspar content and
the low quality of their contained clay prevent them from competing
with early Eocene sandstones as sources of high-quality silica sands.
Their relatively high degree of consolidation, and consequent high
expense of preparation, makes them less desirable than dmie sands as
sources of sandblasting and engine sands. One of the higher quality
later Tertiary sandstones is the upper Miocene and lower Pliocene ( ?)
Santa Margarita Formation, which is quarried near Felton, Santa
Cruz County, mainly for aggregate use. Pleistocene beds in Ventura
County are sources of foundry sand.
Selected References
Goldman, H. B., 1964, Sand and gravel in California, an inventory of deposits,
Part B — Central California : California Div. Mines and Geology Bull. 180-B.
Messner, W. E., 1954, Flotation of Del Monte sand : California Div. Mines Min-
eral Inf. Service, June 1954, p, 4-8.
374 MINERAL AND WATER RESOURCES OF CALIFORNIA
Ries, Henrich, 1949, Properties of foundry sands : California Jour. Mines and
Geology, v. 44, p. 9-35.
Wright, L. A., 1948, California foundry sands : California Jour. Mines and
Geology, v. 44, p. 36-72.
SHALE, EXPANSIBLE
(By J. L. Burnett, California Division of Mines and Geology, Redding, Calif.,
and C. T. Weiler, U.S. Bureau of Mines, San Francisco, Calif.)
Expansible shale is a raw material used to manufacture lightweight
aggregate for concrete. The aggregate is produced by rapidly heat-
ing certain types of common shale in a high-temperature kiln. When
the particles of shale reach temperatures in the vicinity of 1,800° to
2,000°F, they partially melt, forming a slag-like shell around the ex-
terior of the particle. The gas, generated within the particle, is
sealed in by the viscous glass that results from melting. The en-
trapped gas expands to form closed pores which enlarge the volume
of the particle and decrease its apparent specific gravity. The ex-
panded aggregate particle is frothy and cellular on the inside and is
surrounded by a dense, hard shell on the surface.
Expanded shale aggregate combines the desirable features of low
weight with relatively high strength, making it especially useful in
special-purpose lightweight concrete applications such as concrete
block, structural concrete for multi-story buildings, and a variety
of specialized concrete products such as pre-cast and prestressed panels
and beams, and storage tanks.
As construction costs continue to increase and technological im-
provements are made, higher strength lightweight concrete will un-
doubtedly replace concrete made with natural aggregate for many
applications, even though natural aggregate may be less expensive.
The lesser weight of the lightweight concrete will materially lessen
design load factors .and thus afford substantial savings in cost of con-
struction. As utilization of lightweight concrete increases and it
becomes more a general use item, the cost will decrease and the use
become more widespread.
Expansible shale is used in this discussion as a commodity name and
includes three lithologic types: shale, claystone, and slate. These
three types of rock are fine grained, and all have been deposited in
water — either the ocean, a bay, or an inland lake. Although these
rocks have a similar origin, they differ in the amount of compaction
that they have sustained, and this is reflected in their structure. Shale
is a moderately hard, laminated rock; claystone is a softer, poorly
compacted rock which is massive to poorly laminated ; slate is harder
than shale, has been compacted more, and displays such perfect lami-
nation that the rock can he split into thin sheets.
Typical expansible shale is a fine-grained argillaceous rock of ma-
rine origin. The minerals usually found in shale include those of the
clay group, quartz, and feldspar, with minor amounts of organic
carbon, pyrite, calcite, and gypsum.
Undesirable materials are often associated with expansible shale
in a deposit. Weathered shale is normally found at the surface of a
deposit and is undesirable because the process of weathering eliminates
those properties which permit the shale to expand (White, 1959).
MINERAL AND WATER RESOURCES OF CALIFORNIA 375
Sandstone, siltstone, and other coarse-grained sediments do not expand
and will increase the average weight of the aggregate if they are in-
cluded with the raw material. Limestone becomes highly readtiAje
when subjected to intense heating because it is converted to calcium
oxide or "quick lime". Calcium oxide is .actively hamiful to concrete
structures due to expansion and resultant cracking of the structure.
Any or all of these materials may be found in a shale deposit, and,
although small quantities can be tolerated, they should be avoided
through selective mining or removed during processing.
The expansible shale industry in California began in 1932 witli
the completion of the McNear Co. plant near San Rafael. Added in-
centive for a northern California expansible shale industry was created
when specifications for the San Francisco-Oakland B.ay Bridge called
for expanded shale aggregate in the construction of the roadbeds on
the bridge deck. The McNear (^o. supplied part of this aggregate,
and the remainder was produced from a quarry .and plant at Point
Richmond in Contra Costa County. Both of these plants used shale
quarried from the Franciscan Formation.
The first plant in southern California was established in 1940 near
Ventura. The raw material is a bentonitic claystone from the Mudpit
Shale. A^fter the United States entered World War II, lightweight
aggregate was produced near Casmalia, Santa Barbara County for
use in the hulls of ships made with reinforced concrete.
During the years following the end of World War II, commercial
and residential construction increased at a tremendous rate and so
did the demand for lightweight aggregate as shown in figure 71.
Production capacity in the existing plants was enlarged, and several
additional plants were put into operation. In 1952, a plant was opened
near Frazier Park in Ventura County which used bentonitic clay-
stone of Miocene age from the Lockwood Clay. In the following year,
the largest plant in California v,'as established by the Basalt Rock Co.
south of Napa. This plant used marine shale of Cretaceous age from
a quarry near Vallejo and later (1962) opened another quarry west
of Oakville, Napa County. A shale deposit in the Yorba Member of
the Puente Formation (upper Miocene) was opened near Chino, San
Bernardino County in 1958 by the Shale-Lite Corp., although this
operation closed in 1962 due to unsolved problems in product quality
control. In 1962, a plant was opened in San Clemente to supply the
growing market in Orange and San Diego Counties. This plant is
operated by Crestlite Division of Susquehanna-Western, Inc., and
uses shale from the Capistrano Formation of late Miocene and early
Pliocene age.
Occurrences in California
At the present time (1965), expanded shale aggregate is being pro-
duced from five operations in California which are located near San
Rafael, Napa, Ventura, Frazier Park, and San Clemente, and a sixth
plant near Casmalia is producing lightweight aggregate from sin-
tered diatomaceous shale (fig. 72) . Several companies are planning to
build additional plants in the San Francisco Bay Area. Port Costa
Clay Products Co., a subsidiary of Homestake Mining Co., is enlarg-
ing their facilities on Carquinez Strait to produce expanded shale as
well as brick. The Henry J. Kaiser Co. has optioned property near
376 MINERAL AND WATER RESOURCES OF CALIFORNIA
900
Figure 71. Annual production of expanded shale aggregate in California (figures
prior to 1953 are approximate due to incomplete statistics) .
Sunol in Alameda County and plans to j^rodnce lijjhtweight aggregate
from shale of Cretaceous age. In southern California, the Pavolite
Division of Pacific Vegetable Oil Corp. ])urchased the plant and quarry
near Chino, formerly operated by the Shale-Lite Corp., renovated the
plant, and has resumed production.
Deposits of expansible shale in California that are potentially suit-
able for industrial use occur in marine sedimentary formations of
Jurassic, Cretaceous, Eocene, and Pliocene ages. Some shale of Mio-
cene age is suitable, but that in the Monterey Shale and equivalent
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANAT I ON
e
lis- I22- ,p,. ,,„. Expansible shale
quarry and processing plant
i~7 — \ —
IhAMApT)
5\V
>
i^^■hAMAT^^"^ 0«"-'^ !
S S E ?J\ I
,I,„J CASCAbE \. <5^
so"t. — M -^fr"-""'^ '^t^"-
TRINITY <*
. ^ \ r ^iii
ENN^/ BLl^E V- SIERRA
Expansible shale
processing plant
Expansible shale
quarry
A
Sintered diatomaceous
shale quarry and
processing plant
'I.araI, \/ ^
._JX<^
<^ vV
\BENITC(| \ y ./{
■>■-%« rJ r- ■KINGS]
S.M0NTEREV">\ ^ M ^ Tl>*.ARE
SAN '
Cutis ^.\ B»k«"'"W
^ *'_OBISPO
\SANTA">J^
WbaRaI'-^I^^Alos ANGEl.ESi
i- ' \ I N Y O ^ \
^ S^^-
\
377
,\
M O J A V E _j_ ■. 35
SAN BERNARDINO
\
"o"c^..
33-+
120"
^^\^ /~w ^^^\/^"
DESERT
1-^ <^,
jIMl-ERl*'
SALTON
\ V
+ \ + I -^^ "'^'•'' (t^ TROUGH^
117*
Figure 72. Expansible shale in California.
formations ordinarily contains too mncli silica to permit suitable ex-
j)ansion. The Quaternary sedimentary units of California generally
consist of course nonexpansible detritus, although clay being
deposited in 'the bays along the coastline of California is usable.
In the northern Coast Ranges, formations of Jurassic and Cretace-
ous age contain shale of potential commercial interest (Jennings and
others, 1958-1965). The shale is most abundant in two north-trend-
ing belts. One belt is 10 to 20 miles wide and lies along the west side
of the Sacramento Valley from Redding to Fairfield. The Knoxville
Formation, w^hich lies on the western side of this belt, contains shale-
rich rocks which are thousands of feet thick. Minable deposits are
67-164 O— 66— pt. I-
-25
378 MINERAL AND WATER RESOURCES OF CALIFORNIA
present Avhicli are many liiindreds of feet thick and thousands of feet
in exposed lengtli. The other beU. extends from Eureka to Santa
Rosa and contains shale-rich rocks of Cretaceous age.
Shale of Early Cretaceous age also is abundant along the south
and oast flanks of Mount Diablo, Contra Costa County, and on the
southern side of Carquinez Strait near Port Costa. In the central
Coast Ranges, along the east side of the Santa Clara Valley, shale-
bearing units of Late Jurassic to Early Cretaceous age form belts as
much as 4 miles wide and 10 miles long. Although the shale is inter-
layered with sandstone, minable deposits are as much as 1,000 feet
thick and a half a mile in exposed length.
In many places in the California Coast. Ranges, Lower Cretaceous
rocks are overlain by Upper Cretaceous units that also are partly shale.
The Upper Cretaceous shale, however, is commonly interbedded with
standstone so that the shale bodies are generally less than 10 feet thick
and would be difficult to mine. In Solano County, however, an Upper
Cretaceous shale body about 70 feet thick is mined by the Basalt Rock
Co. Another deposit, several hundred feet thick, is mined by the same
company west of Oakville, Napa County.
The Franciscan Formation of Late Jurassic to Late Cretaceous age
also contains expansible shale, but this is commonly interbedded with
sandstone. The Franciscan Fonnation is the source of the raw mate-
rial expanded by the McNear Co. at McXear Point in Marin County.
Here the shale is removed from a deposit approximately 150 feet
thick.
In the southern Coast Ranges, Transverse Ranges, and Peninsular
Ranges of southern California, expansible shale occurs in deposits of
Cretaceous, Eocene, Miocene, and Pliocene ages.
The Es]:)ada Formation (Upper Jurassic and Lower Cretaceous)
occurs in belts as much as three miles long on the north side of the
Santa Ynez Mountains, between Buellton and Santa Barbara, in Santa
Barbara County. The shale is interbedded with sandstone, but the
sandstone layers are thin and sparse, and individual bodies of shale are
100 feet or more in thickness.
The Holz Shale Member of the Ladd Formation (LTpper Cretace-
ous) crops out on the southwestern slopes of the Santa Ana Mountains
in belts as much as one mile long. The shale is interbedded with sand-
stone and minor limestone layers. A shale body 1,000 feet thick and
of possible commercial interest occurs in Silverado Canyon, Orange
County. Other exposures of shale-bearing rocks of Upper Cretaceous
age occur near Carlsbad in San Diego County. Although the shale is
interbedded with sandstone and limestone, shale zones are found
which are commonly 25 to 50 feet thick and contain 80 percent shale.
Rocks of Late Cretaceous age form a large part of the Simi Hills,
which lie in Los Angeles and Ventura Counties, west of Chatsworth.
These rocks consist mostly of sandstone and conglomerate, but a body
of shale about 150 feet thick and as much as two miles in exposed length
lies near the summit of Santa Susana Pass.
The Cozy Dell Formation is extensively exposed in a wide belt of
Eocene rocks that underlies much of the Santa Ynez Mountains, from
Pomt Conception eastward for about 70 miles, in both Santa Barbara
and Ventura Counties. The shale of the Cozy Dell Formation is in-
MINERAL AND WATER RESOURCES OF CALIFORNIA 379
terbedded with sandstone, but minable bodies hundreds of feet thick
are common in both the Ojai and Santa Barbara areas.
Exposures of the Lock wood Clay (Miocene or younger) are found
in an area of about four square miles, near Frazier Park, in the north-
eastern part of Ventura County. This clay is mined and expanded
by Ridgelite Products Co. The deposit is at least 120 feet thick in the
quarry. The Capistrano Formation (Miocene and Pliocene) under-
lies an area of 40 to 60 square miles, near San Juan Capistrano, Orange
County, and contains bodies of shale that are hundreds of feet thick.
A deposit in the city of San Clemente is being mined and processed by
Crestlite Aggregates. The Sycamore Canyon Member of the Puente
Formation crops out extensively in the Chino Hills between the city
of Puente and Prado Dam. In this member, shale is interbedded with
sandstone, but bodies of shale 300 or more feet thick and many
hundreds of feet in exposed length occur north and west of Prado
Dam. Shale from the Yorba Member of the Puente Formation was
expanded at a plant near Chino from 1958 to 1962.
Large areas north of the Santa Clara Valley in Ventura County are
underlain by the Pico Formation (Pliocene) which contains large
quantities of shale. A shale deposit in the Mudpit Shale is quarried
by the Rocklite Co. near the city of Ventura .
Many of the lagoons and bays along the coastline of California con-
tain recent clay deposits which can be dried and expanded into a suit-
able product. The most noteworthy is San Francisco Bay, where clay
deposits averaging 60 feet in thickness cover its entire floor. Limited
testing indicates that much of this material can be expanded, although
drying the clay may be a difficult and expensive process.
Expanded shale is a commodity that must be produced in high vol-
ume at a low cost. The initial cost of establishing an expanding plant
is high, usually 1 to 3 million dollars. As with many other nonmetallic
minerals and construction materials, the marketing situation in the
intended sales area, and the probable cost of mining and transporting
the product to this market, is of equal or greater importance than an
optimum quality raw material. For these reasons, prospecting shoiild
not be carried on solely for the purpose of finding the raw material
with the best ceramic properties but is best carried on in several stages,
the initial steps determining the course of action in each successive
step.
A most important early step is to learn wdiere the major sales area
will be and to determine the volume of sales that can reasonably be
expected. Once the region of major interest has been determined, the
next step is to appraise the sedimentary materials within this area. In
order to be considered, a deposit should be large and uniform so that
inexpensive mining methods can be used, and it should be readily ac-
cessible so that transportation to the market will be inexpensive. Proc-
essing the shale requires rather large quantities of fuel, so proximity
to a fuel source also is important. All these factors, plus the probable
cost of constructing and operating a plant, must be considered to de-
termine whether a commercial operation would be profitable if a suit-
able deposit of raw material was economically available.
When it has been determmed that commercial exploitation is feasi-
ble, the prospector should look for the best raw material wnthin the
380 MINERAL AND WATER RESOURCES OF CALIFORNIA
area of interest. Althougli firing in a ceramic kiln is the final test
of expansibility, many ceramic properties can be estimated by in-
spection of the raw material (Burnett, 1964).
The quantity of usable raw material in California is measurable in
terms of cubic miles of shale, but tlie annual production will, for some
years to come, be measurable in terms of one to several millions of tons.
It would seem, therefore, that no raw material shortage could ever
exist, but, in practice, this is not the case. There are a limited number
of economically minable deposits which are located close to both the
sales area and inexpensive transportation. Urban expansion is nor-
mally accompanied or preceded by zoning ordinances which tend to
strictly control or exclude heavy industrial operations such as an ex-
pansible shale plant.
Outlook
The future for expansible shale will be defined by urban growth
more than by any other single factor. In the next few yeai-s, existing
plant capacities will be sufficient to supply the Los Angeles and San
Francisco Bay areas, and, therefore, any additional facilities in these
areas will have to depend on active competition with established pro-
ducers rather than from large increases in consumption of the product.
If other urban areas increase in size, they will create local markets of
sufficient size to support other plans. The Fresno area is foremost
among these areas, because it is equidistant from the existing expand-
ing plants and close to some of the largest urban growth centers in the
Central Valley.
There is need for additional research in the technology of shale
expansion. Many areas in California have raw materials of marginal
quality or waste products from other industrial operations which
could be used for the production of lightweight aggregate, if more
flexible techniques of processing were known. If a high degree of
flexibility could be designed into a single plant, the degree of expan-
sion of the raw material might be adjustable, so that both a light,
relatively weak jjroduct and a relatively heavy but strong product
could be supplied. This would allow the producer to meet varying
customer needs and improve his competitive position.
Selected References
Burnett, J. L.. 19C4, ProsiJecting for expansible shale : Mining Eng.. v. 16. no. 1.
p. 50-51.
Conley, J. E., Wilson, Hewitt, Klinefelter, T. A., and others, 1948, Production of
lightweight concrete aggregates from clays, shales, slates, and other materials :
U.S. Bur. Mines, Kept, of In v. 4,401.
Hamlin, H. P., and Templin. George, 1962. Evaluating i-aw materials for rotary-
kiln production of lightweight aggregate : U.S. Bur Mines Inf. Circ. 8122.
Herold, P. G., Kurtz, Peter, Planje, T. J., and Plunkett, J. D., 1958, Study of
Missouri shales for lightweight aggregate : Missouri Div. of Geol. Survey and
Water Res.. Rept. Inv. no. 23.
.Jennings, C. W.. Strand, R. G., and others (compilers), 195&-1965, Geologic map
of California : California Div. Mines and Geologj, 27 sheets when completed,
scale 1 : 2.50,000.
White, W. A., 1959. Shale as source material for synthetic lightweight aggregate :
Illinois Indus. Mineral Notes, no. 9 (April 15. 19.59). Illinois State Geol. Sur-
vey, Urbana (mimeographetl).
MINERAL AND WATER RESOURCES OF CALIFORNIA 381
SILVER
(By H. K. Stager, U.S. Geological Survey, Menlo Park, Calif.)
Silver has been searched for, treasured, and fought over since ancient
times. Along with gold it is one of the precious metals and has found
wide use as a measure of wealth and a medium of economic exchange
for about four thousand years. It is a durable and easily worked
metal of beauty and is widely used in the arts and industry.
The United States has almost 2 billion troy ounces of silver in coin-
age and consumed 203 million ounces for this purpose in 1964. Indus-
trial use of silver in 1964 amounted to about 123 million troy ounces, of
which the photographic industry alone consumed about 40 million
ounces. Other major uses were for sterling silverware and jeweliy,
electrical and electronic uses, in brazing alloys, and for dental and
medical purposes.
Silver is found in many types of rocks and environments but the
major deposits are veins in the more acidic volcanic rocks and replace-
ments in limestones and dolomites. Silver rarely occurs alone in na-
ture and usually accompanies other metals such as gold, copper, lead, or
zinc. Thus the prices of these metals have a greater influence on the
production of silver than do fluctuations in the price of silver alone.
Silver was probably flrst discovered in California about 1800, al-
though no reliable records are known to exist. Some early reports
mention that a silver mine on the Alisal Ranch, east of Salinas, on
the flank of the Gabilan Range was worked about 1801. The gold and
silver lode mines of the Mother Lode were discovered about 1850. In
1856 silver was discovered in the South Fork mining district of Shasta
County (No. 5 on fig. 73), followed by Bodie (No. 30) in 1860, Blind
Spring (No. 46) in 1862, Cerro Gordo (No. 49) and Clark Mountain
(No. 63) in 1865, Darwin (No. 51) in 1874, California's largest silver
producing district. West Shasta (No. 6) in 1879, the rich silver mines
of Calico (No. 62) in 1881, Mojave (No. 59) in 1894, and the deposits
at Randsburg (No. 60) in 1919.
The United States has been the leading consumer of silver for many
years but ranked third in silver production (after Mexico and Peiii)
in 1963 and 1964, United States production was 35 million troy ounces
in 1963 and 36 million troy ounces in 1964. California ranks seventh
among the states in total silver production, having produced about 120
million troy ounces since 1848. During 1964, California Avas seventh
in yearly production with a total of 174,000 troy ounces, valued at
$225,000. This was an increase of almost 18,000 ounces over the 1963
production of 156,528 ounces valued at $200,000.
About 90 percent of the silver produced in California in 1964 was
a by-product of base-metal mining and came from three mines in Inyo
County. The Pine Creek mine (No. 47 on fig. 73) of Union Carbide
Nuclear Co. was the leading producer in the State, followed by the
Santa Rosa (No. 50) and Jubilee (near No. 55) mines. The only de-
posit mined primarily for silver, witli significant production, was the
Zaca mine (No. 27) in Alpine County. Some silver was also pro-
duced as a by-product of gold mining in Yuba and Sierra Counties.
The distribution of silver deposits is shown in figure 73 and listed
in table 43.
Silver occurs in all of the geomorphic provinces of California (fig.
73) but the major deposits are in the Mojave Desert, Great Basin,
382
MINERAL AND WATER RESOURCES OF CALIFORNIA
Klamatli Mountains, and Sierra Nevada. The most common silver
minerals found in California ores are cerargyrite (AgCl, mirargyrite
(AgSbSi), freibergite (AgioSb^Si,-?), and electrnm (Au:Ag). How-
ever, there are few districts in which silver is the chief metal of value
and much of the silver produced comes as a by-product from the min-
ing of argentiferous galena, tetrahedrite, tennantite, enargite, chal-
copyrite, and gold. Most of the native gold from the Mother Lode
contains 10 to 20 percent silver. Only 3 of the 10 major districts
(Calico, Clark Mountain, and Blind Spring) produced silver in
greater value than the other metals. Of the 72 mines or districts
shown on figure 73 only in 11 is silver the primary metal of value. In
36 districts it is a by-product of gold mining; in 14 a by-product of
42'.
41°
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EXPLANAT I ON
35
'I.LUIS
^ *'_ OBISPO
\santX^ UjT ~\y'^*
Mo.e than 5.000.000 ozs Ag ^-^ARBARAi"'!^'
* 1.000 to 5.000,000 ozs Ag. ^^
(Production plus reserves)
Taken from U.S.G.S. Map IIR-a4
34°-f-
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)60
a64
\
7
,OS ANGELESi
MOJAVE -\-\3b
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117°
116°
Figure 73. Silver in California (numbers refer to table 43).
MINERAL AND WATER RESOURCES OF CALIFORNIA 383
Table 43. — Silver in California {data from McKnight and others, 1962)
MINES IN WHICH SILVER IS THE PRINCIPAL METAL OF VALUE
Index number on
fig. 73 District or region
5 South Fork (Chicago mine).
20 Calistoga (Silverado, Palisade mine).
27 Monitor (Zaca mine).
28 Mount Patterson ( Silverado and Ken tuck mines) .
43 Boot Jack.
46 Blind Spring.
61 Grapevine (Waterman mine).
62 Calico.
63 Clark Mountain (Ivanpah in part).
64 Cima (Death Valley mine).
66 Lava Beds.
MINES IN WHICH SILVER IS A BY-PRODUCT OF COPPER MINING
1 SqHiaw Creek (Blue Ledge mine).
3 Island Mountain (Island Mountain mine).
6 West Shasta.
7 Bully HUl.
9 Lights Canyon (Engels, Superior mines).
10 Genessee (Walker mine).
24 lone (Newton mine).
25 Campo Seco (Penn Mine).
32 West Belt (Quail Hill area).
33 Copperopolis (Keystone-Union, North Keystone mines).
47 Bishop Creek (Pine Creek tungsten mine).
MINES IN WHICH SILVER IS A BY-PRODUCT OF LEAD AND/OR ZINC MINING
8 Cow Creek (Ingot, Afterthought mine).
15 Yankee Hill.
41 Hunter Valley (Blue Moon mine).
48 Black Canyon.
49 Cerro Gordo.
50 Lee (Santa Rosa mine).
51 Darwin.
52 Modoc.
.j3 Panamint.
54 Carbonate (Queen of Sheba mine).
55 Resting Springs (Tecopa).
56 Slate Range.
71 Silverado (Santa Rosa, Blue Light).
72 Santa Catalina Island.
MINES IN WHICH SILVER IS A BY-PRODUCT OF LODE AND/OR PLACER GOLD MINING
2 Dillon Creek (Klamath River in part, Siskon mine).
4 French Gulch-Deadwood (Brown Bear, Washington, and
Niagara Summit mines).
11 Sierra City (Sierra Buttes mine).
12 Washington (Graniteville, Spanish, Gaston mines).
13 Alleghany.
14 Slate Creek (La Porte).
16 Oroville.
17 Hammonton (Yuba River).
18 Nevada City.
19 Ophir.
21 Folsom.
22 Placerville.
23 Plymouth-Jackson.
26 Mokelumne Hill.
29 Masonic.
30 Bodie.
384 MINERAL AND WATER RESOURCES OF CALIFORNIA
Table 43. — Silver in California (data from McKnight and others, 1962) — Con.
MINES IN WHICH SILVER IS A BY-PRODUCT OF LODE AND/OR PLACER GOLD MINING COll.
Index number on
fig. 73 District or region
31 Angels Camp.
34 Carson Hill (Car.son Hill mine).
35 Columbia Basin.
36 Sonora.
37 Soulsbyville-Tuolumne.
38 Jamestown.
39 Shawmut (Eagle-Shawmut mine).
40 Groveland-Big Oak Flat.
42 Hites Cove.
44 Mammoth Lakes.
45 Chidago.
57 Cove.
58 Amalie.
59 Mojave.
60 Randsburg.
65 Buckeye (Bagdad Chase mine).
67 Dale ( Monte Negro ) .
68 Eagle Mountain.
69 Paymaster (Paymaster mine).
70 Cargo Muchacho.
lead and/or zinc mining; and in 11 it is a by-product of copper
mining.
The geologic settings of silver-bearing deposits in California are
many and varied. About one-third of the total California silver pro-
duction has been mined as a by-product from large massive sulfide
replacement bodies along axes of broad folds in Devonian rhyolitic
rocks in the West Shasta district. Along the Mother Lode silver has
been produced as a by-product from placer gold deposits and from
quartz veins in slates, granodiorite, and serpentines of the Sierra
Nevada. In the old Monitor district of Alpine County silver ore is
being mined from braided fissure zones and impregnations of silver
minerals in highly altered andesite. At Bodie it was mined as a by-
]:)roduct of gold from quartz veins in andesite. Veins along parallel
faults in a Jurassic granitic stock yielded the silver ores of the Blind
Spring district. In the Bishop Creek district silver is produced as
a by-product from timgsten-copper-molybdenum ores in contact meta-
morphic deposits in Paleozoic marble. Replacement bodies near the
axis of a plunging anticline in Devonian limestone yielded silver as a
by-product of lead-zinc ore at Cerro Gordo. At the Santa Rosa mine
silver is produced as a by-product of lead mined from veins in tactitic
Permian limestone and ore shoots along bedding fractures in Missis-
sipian limestone. The Darwin district has yielded silver as a by-prod-
uct of lead mined from replacement bodies along and near faults in
tactitic Pennsylvanian limestone adjacent to a granodiorite stock.
Mines in the Randsburg district have produced silver and gold from
intersecting vein systems in Precambrian biotite schist, amphibole
schist, and quartzite in the footwall of a large flat fault. In the Mojave
district veins along faults in Miocene dacite flows and plugs, and on
the contact between flows and underlying Upper Jurassic quartz mon-
zonite have yielded silver as a by-product of gold mining. At Calico
high-grade silver ore was mined from veins along, or near faults and
from disseminated deposits in shattered Miocene volcanic rocks and
MINERAL AND WATER RESOURCES OF CALIFORNIA 385
lake beds. Replacement bodies in Mississippian limestone and Devo-
nian dolomite, in part localized by fractures near a quartz monzonite
sill, yielded the silver ores of the Clark Mountain district.
California's greatest silver resource potential probably still lies in
undiscovered, or unmined, copper ore bodies in the Klamath Moun-
tains, gold veins of the Sierra Nevada, and lead-zinc ore bodies in the
Darwin and Cerro Gordo areas. Silver-rich epithermal veins in Ter-
tiary volcanic rocks in the Great Basin and Mojave Desert will prob-
ably also yield additional silver ore.
Geophysical exploration followed by drillmg is probably the most
effective method for finding silver-bearing copper ore bodies in the
Klamath Mountains. Extensive geochemical prospecting in the Great
Basin, Mojave Desert, and Sierra Nevada regions is warranted, par-
ticularly in the areas of Tertiary andesitic and rhyolitic rocks.
Selected References
Davis, L. E., 1964, The mineral industry of California : U.S. Bur. Mines Minerals
Yearbook, 1963, v. 3, p. 159-223.
Hill, M. R., 1963, Silver: Oalifomia Div. Mines and Geology Mineral Inf. Service,
V. 16, no. 6, p. 1-8.
McKnigM, E. T., Nevrman, W. L., Klemic, Harry, and Heyl, A. V., Jr., 1962,
Silver in the United States (exclusive of Alaska and Hawaii) : U.S. Geol.
Survey Min. In v. Resource Map MR-34.
Ryan, J. P., 1964, Silver: U.S. Bur. Mines Minerals Yearbook, 1963, v. 3, p.
1001-1024.
Stewart, R. M., 1957, Silver, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 529-!537.
SODIUM CARBONATE
(By G. I. Smith, U.S. Geological Survey, Menlo Park, Calif.)
Sodium carbonate, known industrially as soda ash, occurs in na-
ture chiefly where concentrated by evaporating lake waters. It is used
in large quantities in the manufacture of glass and chemicals, and in
smaller quantities for paper products, soda and detergents, nonfer-
rous metals, and water softeners.
Sodium carbonate has been used since the time of early Egyptian
cultures, when efflorescences composed of it were collected from the
edges of saline lakes in that area. In early European and American
civilization it was obtained by burning marine plants, such as seaweed,
which formed an ash from which sodium carbonate could be extracted.
The name "soda ash"' is inherited from this process. In 1791, an in-
dustrial process was developed in France which ended production by
this method. In 1860, the Solvay method was developed in Belgium,
and this process, Avhich uses salt, ammonia, and limestone as raw ma-
terials, provides most of the sodium carbonate used in the Avorld today
(MacMillan, 1960).
In 1963, the annual production capacity of sodium carbonate prod-
ucts in the United States were estimated to be 7,050,000 short tons
(Chemical and Engineering News, 1963). Products manufactured
by the Solvay process account for 5,730,000 short tons (81 percent),
and natural deposits provided the balance. California's share in this
production capacity from natural deposits was 370,000 short tons
(5 percent) , and Wyoming's was 950,000 short tons ( 14 percent) . The
386 MINERAL AND WATER RESOURCES OF CALIFORNIA
total value of 1963 production from natural sources was $27,600,000
(MacMillan, 1964). Individual capacities of California producers
■were reported as follows (Garrett and Phillips, 1960) :
Short tons
American Potash & Chemical Corp 150,000
Stauffer Chemical Co 150,000
Pittsburgh Plate Glass Co 70,000
Two producers, FMC Corp. and Stauffer Chemical Co., provided the
indicated Wyoming production by mining beds of the mineral trona
(Na^COa-NaHCOa -21120). In 1965, an additional four companies
were developing or actively exploring Wyoming properties (Engi-
neering and Mining Journal, 1965). Production capacity from that
state can therefore be expected to increase, and this will provide addi-
tional competition for available western markets.
Because sodium carbonate is a relatively inexpensive product — in
1963, it sold for $32 per ton in bulk lots (MacMillan, 1964)— a major
percentage of its price comes from the cost of transporting it to the
customer. Trucking and rail rates between sources and markets thus
become important considerations in the economic practicality of a
deposit. The natural deposits in Wyoming and California therefore
have an advantage in capturing western markets. Within this area,
though, the deposits in Wyoming generally have freight-rate ad-
vantages in supplying customers in the northwestern states where
large quantities are used in the production of paper. The California
deposits have comparable freight-rate advantages for markets in much
of California and the southwestern states, but the demand for sodium
carbonate in these areas is less.
The three producers of sodimn carbonate in California operate on
two deposits, Searles Lake in San Bernardino County (fig. 74, loc.
A), and Owens Lake in Inyo County (loc. B). American Potash &
Chemical Corp. and Stauffer Chemical Co., West End Division, pro-
duce from brines pmuped from Searles Lake. Pittsburgh Plate Glass
Co. produces from brines from O^vens Lake. All three plants extract
sodium carbonate from the impure brines by complex processes that
involve carbonation, evaporation, and cooling. The plants at Searles
Lake produce other products as well ; the plant at Owens Lake produces
sodium carbonate or sodium sesquicarbonate as its only products ( Ver
Planck, 1957).
Prior to the full development of these operations on Owens and
Searles Lakes, sodium carbonate was produced in small quantities by
other plants on these deposits (Garrett and Phillips, 1960). The
earliest operations were on Owens Lake in the years following 1886.
In these operations, trona was precipitated in evaporation ponds, and
then calcined to produce sodium carbonate. Similar operations were
attempted on both Owens and Searles Lakes, but interest was sporadic
until about the time of World War I. Then, the accelerated require-
ments for both soda ash and potash (Avhicli was also found to occur
in dry lakes) prompted several attempts to establish large-scale pro-
duction from both deposits. It was not until 1926, though, that the
.Vmerican Potash & Chemical Corp. began successful production of
sodium carbonate on an industrial scale from Searles Lake. In 1927,
it was first produced from this deposit by the AVest End Chemical
Co. (now a division of the Stauffer Chemical Co.) . In the period since
MINERAL AND WATER RESOURCES OF CALIFORNIA 387
3r-
EXPLANAT ION
A . Sea r I es Lake
B. Onens Lake
1 i !
FiGTRE 74. Ivocatiou of sodimii carbonate producers in California.
"World "War I, several smaller plants also produced from the Owens
Lake deposit, but only the relatively modern plant of the Pittsburgh
Plate Glass Co. is still in operation.
The geologic settings of Searles and Owens Lakes arc similar.
Both deposits were formed by the drying up of large saline lakes
that formed during late Quaternary time in closed basins. These
lie in the southwest part of the Great Basin, and during the wetter
periods they contained large lakes that were integrated into a chain
(Gale, 1914). Owens Lake was the tirst lake in this chain, and it
received most of its water from the east side of the Sierra Nevada.
When Owens Lake was about '200 feet deep, it overflowed southward,
first into Indian Wells Valley to form China Lake, and then into
Searles Valley to form Searles Lake which reached a maxinunn level
640 feet above the present valley floor. At these times Searles and
China Lakes coalesced into one large body of water and overflowed
into Panamint Valley. The lake in Panamint Valley, m turn, over-
flowed into Death Valley.
For long periods during the later parts of Quaternary time, the
chain of lakes ended with Searles Lake. During these periods the
more soluble components dissolved in the waters became concentrated
in Searles Lake. When climatic changes caused it to become dry, or
nearly so, the dissolved salts were deposited on the valley floor.
Such changes in climate were repeated many times during late
Quaternary time. In Searles Lake, each cycle produced a layer of
mud (formed during the time a large lake occupied the valley) and
an overlying layer of salines (formed during the sul)sequent period
of dryness). These saline layers differ in composition. The major
differences are the result of changes in the composition of the saline
materials dissolved in the tributary waters; the snuiller differences are
the results of the specific climatic characteristics of successive drying
episodes.
388
MINERAL AND WATER RESOURCES OF CALIFORNIA
The saline deposits being exploited in Searles Lake are among those
that differ slightly as a result of minor climatic differences at the
time of deposition. The deposits are grouped into two zones, both
of which extend over areas of about 40 square miles (Flint and Gale,
1958; Haines, 1959; and Smith, 1962). The upper zone, formed
during the post -Wisconsin dry period, is generally TO to 80 feet thick
in the areas being used for commercial purposes. The lower zone,
formed during the middle Wisconsin dry period, is 30 to 40 feet
thick in these areas. It is separated from the upper layer by a mud
layer 12 to 14 feet thick. Brines occupy the interstices of both saline
layers, and they are estimated to account for about 40 percent of
their total volume. These brines are pumped to the chemical plants
on the edge of the lake where they are processed to extract the valuable
saline components. Chemical analyses of brines representative of
those being pumped from these two zones are given in table 44.
Table 44. — Chemical analyses of brines
NajCOs (percent)
NaHCOa
NajSOj
NaCl
KCl
Na2B40:
Total dissolved solids (percent)
Searles Lake i
Upper zone
4.8
.1
6.8
16.2
4.9
1.6
34.6
Lower zone
6.1
0
6.7
16.2
3.2
1.7
34.5
Owens Lake 2
(in percent)
8.6
0(?)
4.6
16.8
.7
.5
1 Garrett and Phillips, 1960, table 3; values in grams per liter unless indicated as weight percent.
2 Dub, 1947, table 3, analysis of April 1940.
Owens Lake never dried up during these periods. Saline waters
that collected in the basin during periods of nonoverflow were later
washed downstream. However, since the last overflow (probably 2
to 4 thousand years ago), salines have accumulated in the basin, raid
in about 1913, when the Owens River was diverted into the Owens
Valley aqueduct (which leads to Los Angeles), the lake began to dry
up. By 1921, a layer of salines had formed, and brines from this pro-
vide the raw material of present operations. A typical analysis of
these brines is listed in table 44.
Future sources of natural sodium carbonate in California appear to
be limited to the Owens Lake and Searles Lake deposits. Their
reserves have been estimated as more than 58 million tons and 150
million tons, respectively (Garrett and Phillips, 1960). At current
plant capacities, this supply would last over 500 years. Although
demand in the Western States will increase, the continued develop-
ment of the enormous resources in Wyoming Avill tend to limit the
role of California producers in supplying this demand.
Selected References
Chemical and Engineering News. 1963. TGS maps entr.v into so<la ash production :
Chem. Eng. News. v. 41 (July-Sept.), no. 34, p. 19-20.
Dub, G. D., 1947. Owens Lake — source of sodium minerals [California] : Am.
Inst. Mining Metall. Engineers Tech. Pub. 2.235, Mining Technology, v. 11.
no. 5, 13 p.
MINERAL AND WATER RESOURCES OF CALIFORNIA 389
Engineering and Mining Journal, 1965, Wyoming, in This month in mining:
Eng. Mining Jour., v. 166, no. 4, p. 158.
Flint, R. F., and Gale, W. A., 1958, Stratigraphy and radiocarbon dates at
Searles Lake, California : Am. Jour. Sci., v. 256, no. 10, p. 689-714.
Gale, H. S., 1914, Salines in the Owens, Searles, and Panamint basins, south-
eastern California : U.S. Geol. Sui-vey Bull. 580-L, p. 251-323.
Garrett, D. E., and Phillips, J. F., 1960, Sodium carbonate from natural sources
in the United States, in Industrial minerals and rocks: Am. Inst. Mining
Metall. Petroleum Engineers, p. 799-808.
Haines, D. V., 1959, Core logs from Searles Lake, San Bernardino County, Cali-
fornia : U.S. Geol. Survey Bull. 1,045-E, p. 139-317.
MacMillan, R. T., 1960, Sodium and sodium comiwunds, i7i Mineral facts and prob-
lems : U.S. Bur. Mines Bull. 585,1). 745-765.
, 1964, Sodium and'.so<iium compounds: U.S. Bur. Mines. Minerals Year-
book, 1963, V. 1, p. 1,035-1,043.
Smith, G. I., 1962, Subsurface stratigraphy of late Quaternary deposits, Searles
Lake, California — a summary : Art. 82, in U.S. Geol. Survey Prof. Paper
450-C, p. C65-C69.
Ver Planck, W. B., 1957, Sodium carbonate : California Div. Mines Bull. 176, p.
539-541.
SODIUM SULFATE
(By G. I. Smith, U.S. Geological Survey, Menlo Park, Calif.)
Sodium sulfate, knoAvn industrially as salt cake, is produced in the
United States both from natural deposits and as l3y-products of sev-
eral chemical processes. About 70 percent of production is used in
pulp and paper industries ; the remaining 30 percent is used by manu-
facturers of glass, ceramic glazes, detergents, stock feeds, dyes, tex-
tiles, medicines, and other assorted chemicals (MacMillan, 1964).
Natural deposits of sodium sulfate are common in many parts of
the world, especially arid regions. Significant production from for-
eign deposits has come from Spain, Kumania, Italy, Russia, Argen-
tina, Chile, Mexico, and Canada (mostly Saskatchewan). At pres-
ent, United States production from natural sources comes from Cali-
fornia, Wyoming, and Texas, but deposits that might be utilized also
occur in Colorado, Idaho, Nevada, New Mexico, North Dakota, Ore-
gon, and Utah (Goudge and Tomkins, 1960). In 1963, these active
deposits provided 36 percent of the Nation's total output, or about
435,000 short tons, ha\nng a value of $8,392,000 (MacMillan, 1964).
During the same period, industrial sources provided 64 percent of
the Nation's total, or about 770,000 short tons. Processes that make
sodium sulfate as a by-product include those tliat manufacture hydro-
chloric acid, rayon, phenol, sodium bichromate, boric acid, and cello-
phane. Industrial sources in California are the U.S. Borax and
Chemical Corp., and the Stauffer Chemical Co., Avhich produce sodium
sulfate during the conversion of borax to other products (MacMillan,
1964).
In 1963, bulk lots of domestic salt cake sold for $28 per ton at the
works (MacMillan, 1964). Inasmuch as it is a fairly inexpensive
product, transportation costs account for a significant part of the
ultimate price to the consumer. Producers close to large markets
thus have a potential advantage. For this reason, markets in the
Eastern United States are chiefly supplied from industrial by-product
sources, and those in the Western States depend more heavily upon
natural deposits in California, Texas, Wyoming, and Canada.
390
MINERAL AND WATER RESOURCES OF CALIFORNIA
Two companies in California, the American Potash & Chemical
Corp. and the Stauffer Chemical Co. (West End Division) with
plants at Searles Lake (fig. 75), provide much of the United States
production from natural sources. In 1951, the annual plant capacity
of American Potash was reported to be about 220,000 short tons
(Ryan, 1951), and in 1958, Stauffer was reported to have an annual
capacity of about 145,000 short tons (Chilton, 1958). Both com-
panies extract sodium sulfate (among other products) from complex
brines pumped from the interstices of the late Quaternary saline de-
posits of Searles Lake. Tliis deposit and its geologic setting are de-
scribed in the section on sodium carbonate. Descriptions of the
industrial processes used to extract the product are given by Ryan
(1951), Ver Planck (1957), Chilton (1958), and Goudge and Tomkins
(I960).
Other potential sources of sodium sulfate in California are listed
in table 45. All deposits except one in the Durmid Hills — are late
Quaternary to Recent saline bodies formed in closed basins. Owens
lake, in the Great Basin, is predominantly a carbonate saline body.
Dale and Danby Lakes, in the Mojave Desert, lie in an area character-
ized by sulfate and chloride saline bodies. Soda Lake, in the Cali-
fornia Coast Ranges, lies in a sag pond along the San Andreas fault ;
its composition suggests that this is a province with sodium sulfate-
rich water, although most of it drains to the sea. The deposit in the
Durmid Hills is in late Cenozoic lacustrine deposits that have been
steeply folded by displacements along the nearby San Andreas fault.
Some of these deposits consist chiefly of sodium sulfate in brine;
others contain high percentages in the solid minerals. Relatively
simple extraction and refinement methods produce a marketable grade
of sodium sulfate from either type of material ; these methods gener-
ally depend upon the uncommonly large decrease in the solubility of
sodium sulfate with decreasing temperature. In some instances, a
Searles LaKe
0*ens Lake
Dale Lake
Durmid Hi
Soda Lake
Danby Lake
Figure 75. Sodiuui sulfate deposits in Calif oi-uia.
MINERAL AND WATER RESOURCES OF CALIFORNIA 391
Table 45. — Sociinm sulfate deposits in California
Occurrence
No.
on fig.
75
Type of occurrence '
Record of production
SearlesLake^ _..
1
2
3
4
5
6
Brine-filled saline body (see table 44 for
brine analyses). Major sulfate miner-
als: thenardite, burkeite, hanksitc,
and aphthitalite.
Brine-filled saline body (see table 44 for
brine analyses). Major sulfate min-
erals- burkeite, thenardite, mirabilite.
Brine-filled saline lenses. Major sulfate
mineral: thenardite.
Thenardite and bloedlte in deformed
upper Cenozoic shale and sandstone.
Mirabilite crust, some bloedlte
Disseminated mirabilite crystals
Production from brine 1926
Owens Lake ' -
to present.
No production.
Production 1937-48, from
DaleLake*
Dur mid Hills <
brines; several attempts to
produce from solids.
Some past production from
Soda Lake '.
opencut mines.
Some past production from
Danby Lake *
crusts.
Minor past production.
1 Mineral compositions: Thenardite, NaaSO^; Mirabilite, Na2S0i. IOII2O; Burkeite, 2NajS0j. NajCOj;
Hanksite, 9Na2S04. 2Na2C03. KCl; Aphthitalite. K3Na(S04)2; Bloedlte, Na2Mg(S04)2. 4H2O.
2 Smith and Haines, 1964.
3 Dub, 1947.
* Ver Planck, 19.i7.
marketable grade has been produced solely by spraying the sodium
sulfate-bearing brine into cool air. This technique is used on Searles
Lake by the American Potash & Chemical Corp. to produce sodium
sulfate decahydrate (mirabilite) for use in the plant cycle, but a more
complex process is used in the production of anhydrous sodium sulfate
(thenardite) for shipment, "VVlienever mirabilite is produced from
other deposits by these methods, it is generally dehydrated to thenard-
rite prior to shipment because 56 percent of the weight of mirabilite
is water. Dehydration is difficult on an industrial scale, though, be-
cause at normal drying temperatures, the solubility of sodium sidfate
decreases with increasing temperature so that crystallized material
tends to form an insulation on the heating surface.
Tlie presently known resources of sodium sulfate in California are
probably adequate to maintain present production for many years
to come. Estimates of the quantities in Searles Lake have not been
published, but calculations based on published data indicate that many
years' supply exists in the brines, and that a much larger quantity is
potentially available from the solution or mining of the enclosing
saline minerals. To a large extent, the life of this deposit also depends
on the reserves of other marketable products because all are co-products
of the present plants. Other deposits in the State might become eco-
nomically feasible in the future. Of these, Owens Lake is probably
the largest and has been estimated to contain 24,000,000 short tons of
sodium sulfate (Dub, 1947) ; only part of this w^ould be recoverable,
though, and the lack of past production suggests that engineering or
marketing problems exist which might limit the recovery to a relatively
low percentage. The other deposits in California might supply ma-
terial at present rates for a few years.
Selected References
Chilton, C. H.. 1958, Crytallization — Key step in sodium sulfate process : Chem.
Eng., Aug. 11, p. 116-119.
Dub. G. D., 1947, Owens Lake, source of sodium minerals (California) : Am. Inst.
Mining Metall. Engineers Tech. Pub. 2235, Mining Technology, v. 11, no. 5, 13 p.
392 MINERAL AND WATER RESOURCES OF CALIFORNIA
Goudge, M. F., and Tomkins, R. V., 1960, Sodium sulfate from natural sources, in
Industrial minerals and rocks : New York, Am. Inst. Mining Metall. Petroleum
Engineers, p. 809-814.
MacMillan, R. T., 1964, Sodium and sodium compounds : U.S. Bur. Mines Minerals
Yearbook, 1963, v. 1, p. 1035-1043.
Ryan, J. E., 1951, Industrial salts ; production at Searles Lake : Mining Eng., v. 3,
no. 5, p. 447-452.
Smith, G. I., and Haine.s, D. V., 1964, Character and distribution of nonclastic
minerals in the Searles Lake evaporite deposit, California : U.S. Geol. Survey
Bull. 1181-P, p. P1-P58.
Ver Planck. W. E.. 1957, Sodium sulfate: California Div. Mines Bull. 176, p.
543-545.
STONE, CRUSHED AND BROKEN
(By H. B. Goldman, California Division of Mines and Geology, San Francisco,
Calif.)
Stone production is one of the oldest and most extensive mineral
industries in California. In the late 1800's, dimension stone was pro-
duced in the State in much greater volume than crushed stone. Durino;
the past 50 years the output of dimension stone has dwindled, while the
production of crushed stbne has increased many fold. Greatly in-
creased use of crushed stone for aggregate, especially in asphalt con-
crete for paving, and the marked decrease in use of dimension stone
for building stone, paving blocks, or curbing is largely responsible for
this trend.
In 1964, California ranked third among the states in stone produc-
tion, with a total output of approximately 45,710,000 short tons, valued
at $61,391,000. Crushed stone ranked in value only behind petroleum
products, cement, and sand and gravel, among California's mineral
commodities.
Although the terms "rock" and "stone" commonly are used synony-
mously, they have different meanings when strictly applied. "Rock"
has been defined variously by geologists, but in the stone industry it is
applied to any mass of mineral aggregate as it exists in its natural state
and in place. "Stone" refers to individual blocks, masses, or frag-
ments that have been broken or quarried from bedrock exposures, and
are intended for commercial use.
Most deposits of economic minerals have formed under relatively
uncommon geologic conditions, but stone is obtained from the ordinary
rocks that constitute the earth's crust. The materials that can be
classed as stone are numerous, widespread, and of a wide range of
geologic ages and modes of origin.
Stone has many industrial applications, but these can be divided
into two general classifications by usage : ( 1 ) crushed and broken stone,
and (2) dimension stone. Crushed and broken stone includes all
stone in wliich the shape is not specified, such as that used as aggregate,
railroad ballast, and rijjrap. Dimension stone is produced to speci-
fied dimensions, and includes stone employed as building stone, monu-
mental stone, curbing, and flagstone (see section on Dimension stone
in this volume).
For most uses, crushed or broken stone should be durable, dense,
sound, hard, strong, able to withstand high temperatures, and tend to
break into suitably sliaped fragments. In almost all uses, stone must
resist the chemical action of weathering. Stone to be used for certain
special pui-poses, such as the limestone used in agriculture, glass manu-
MINERAL AND WATER RESOURCES OF CALIFORNIA 393
facture, or the sugar refining industry, must be chemically suited to
these applications.
Crushed and broken stone commonly is further subdivided, on the
basis of use, into (1) crushed stone, (2) ripraj), (3) furnace flux,
(4) refractory stone, (5) agricultural stone, and (6) stone used for
other purposes. Crushed stone is mainly used as aggregate in asphalt
concrete for paving purposes, railroad ballast, aggi-egate base, and
fill. Riprap consists of large broken stone used wit hout a binder, prin-
cipally for jetties, breakwaters, and seawalls which are intJended
primarily to resist the physical action of water. Furnace flux consists
of limestone and marble used for cliemical purposes in the refining of
iron ores and in other metallurgical practices. Refractory stone, such
as (luartzite, mica schist, dolomite, and soapstone is used in the manu-
facture of refractory brick, aijd for furnace and ladle linings. Agri-
cultural stone includes any type of stone that is added to soil, either
as a fertilizer or a soil-conditioner. The category "other purposes,"
includes crushed stone used as a filler, poultry grit, roofing granules,
stone sand, and terrazzo granules; in the production of mineral wool,
stucco, artificial stone, and mineral food; in coal mine dusting; and
for various chemical applications.
Many materials, that by definition can be classified as stone are
considered as separate commodities. Dolomite, limestone, vein quartz
and quartzite, sand and gravel, and specialty sands, as well as such
stone-like nonmetallic materials as diatomite, pumice, perlite, volcanic
cinders, and soapstone are described more completely elsew^here in this
volume.
Rocks used as crushed and broken stone in California
The stone industry recognizes the following stone classification based
mainly on composition and texture : (1) granite ; (2) basalt and related
rocks; (3) limestone; (4) marble; (5) sandstone; and (6) miscellane-
ous stone (including conglomerate, greenstone, shale, mica schist, and
tuffaceous volcanic rocks). Most of these types are abundant and
widespread in California, as shown on Figure 76, and listed in table 46.
Table 46. — Principal crushed and broken stone quarries in California
[Locations shown on fig. 76]
GRANITE
1. Union Granite Co., Rockliu, Placer County.
2. Guy F. Atkinson, Riverside, Riverside County.
3. J. B. Stringfellow, Riverside, Riverside County.
4. Granite Rock Co., Watsonville, San Benito County.
5. Hansen, Silvey, and Sinnott, Felton, Santa Cruz County.
SANDSTONE
6. Blake Bros., Riclimond, Contra Costa County.
7. Quarry Products, Inc., Point Richmond, Contra Costa County.
8. Sweetser Bros., Rosamond, Kern County.
9. Basalt Rock Co., McNear Point, Marin County.
10. Hutctiinson Co., Greenbrae, Marin County.
11. Pacific Cement and Aggregate, Inc., Brisbane, San Mateo County.
12. Guy F. Atkinson, Rincon, Santa Barbara County.
18. Rancho Guadalasca, Camarillo, Ventura County.
67-164 O — 66— pt. I 26
394 MINERAL AND WATER RESOURCES OF CALIFORNIA
Table 46. — Principal crushed and broken stone quarries in California — Continued
BASALT (AND BHXATED VOLCANIC ROCKS)
14. Gallagher and Burk, Inc., Oakland, Alameda County.
15. A. C. Goerig, Orinda, Contra Costa County.
16. Basalt Rock Co., Inc., Novato, Marin County.
17. Basalt Rock Co., Inc., Napa, Napa County.
18. Don Weaver, Jucumba, San Diego County.
19. J. M. Nelson, Cordelia, Solano County.
20. Hein Bros. Basalt Rock Co., Petaluma, Sonoma County.
LIMESTONE
21. California Rock and Gravel Co., Cool, El Dorado County.
22. El Dorado Limestone Co., Inc.. Shingle Springs, El Dorado County.
23. Premier Marble Products, Lone Pine, Inyo County.
24. Kaiser Aluminum and Chemical Corp., Natividad. Monterey County.
25. Industrial Rock Products, Wrightwood, San Bernardino County.
26. C. K. Williams, Cushenbury, San Bernardino County.
27. Eaton and Smith, Paso Robles, San Luis Obispo County.
28. Marks Materials, Inc., Rockaway Beach, San Mateo County.
29. Kaiser Cement and Gypsum Corp., Los Altos, Santa Clara County.
30. Sonora Marble Aggregates. Sonora, Tuolumne County.
MISCELLANEOUS STONE
31. La Vista Quarries, Hayward, Alameda County.
32. San Leandro Rock Co., San Leandro, Alameda County.
33. Ry-lite Corp. of California. Altaville, Calaveras County.
34. Henry J. Kaiser, Clayton, Contra Costa County.
35. Pacific Cement and Aggregates, Clayton, Contra Costa County.
36. Gravelle and Oravelle, Trinidad Quarry, Humboldt County.
37. Desert Rock Milling Co., Randsburg, Kern County.
38. Connolly-Pacific Co., Catalina Island, Los Angeles County.
39. Riverside Cement Co., Catalina Island, Los Angeles County.
40. Minnesota Mining and Mfg. Co., Corona, Riverside County.
41. Brubaker-Mann Co., Barstow, San Bernardino County.
42. Canyon Rock Co., San Diego, San Diego County.
43. Kenneth H. Golden Co., San Diego, San Diego County.
44. Robert Guerra, Morro Bay, San Luis Obispo County.
45. Mirassou Bros., Los Gatos, Santa Clara County.
SLATE
46. Placerville Slate Products, Placerville. El Dorado County.
Granite
The term "granite'" is commonly applied to medium- to coarse-
grained igneous rocks that consist mainly of feldspar and quartz, with
subordinate amounts of ferromagnesian minerals. In the stone in-
dustry, and in the following discussion, the terms "granite" and "gran-
itic rock" are used even more broadly to refer to various intrusive ig-
neous rocks with granitoid textures, and to some metamorphic rocks
with gneissic textures.
Most unweathered granitic rocks are hard, s-trong, tough, and resist-
ant to abrasion, impact, and chemical attack. These properties make
granitic rock well suited to use as building stone, riprap, and ag-
gregate.
Granitic rocks occur mainly in large bodies, known as batholiths,
which are exposed over many square miles. In California, granitic
rocks occur mostly in the Sierra Nevada and southern California
batholiths and in smaller mas.ses in the Klamath Mountains and the
MINERAL AND WATER RESOURCES OF CALIFORNIA
395
123' 122' 121'
I'Wh A M A T }f^^^ O M O DO C
■ / SHjJsTA V J— V ^^
^1 TRINITY < / ? ' 'V^S^V^
-M.nJ CASCAbE
<^-^-.^=.
,0% i \ .-'I
TEHAMA ^/^. /-„,,., ^„
. ^\ ^. ^'
,ENN / Bli^E y siERs^
^°^. I V;""^; L/<!>>^'^nevada;\
y\ y\ voi.o'^-i !4'e/JiT)Rai)Q,- N<j_
-XTiJf^r^^' -^ N\,' TUOLUMNE ,
123 3?4^^?>C«'"''*''^ii V •3". y•-^
Fr„r.-,t^,rT^«?>i-^N- ,-<=> \. -^ /
39.
118'
'j^.V»AK,(^ \/ C"
37*-
122°
^\MERrt:gi-'\ •^''
'* saW\ V
'ilj. W. ^f RESNg
\BENiT(J] \ "7 yx
>IONTEREY '^ V J-
-v.\ <<^
mon6\ -H 38'
'MARIPOSA/ 'jj
— X
, Hishop "v
^^ ^^ \
117'
.23
SAN
t^are"^^ \ \ x;^-
yjL^ '• —
n
■\
--r*' OBISPO
35'-|- f'^SANTX^sJ^
IK E R N
lARBARA] A-^^ WlOS ANGELESl
SAN BERNARDINO '^^
I
i J I I : I
3.«+
121°
100 150 MILES
DESERT ■>
X.'^N^ R>vylsP s, I D E \
^3 8 \%% i\iMPEi^^^JT^-^ )
33--(- + \ + ' ^"^ '>'^'^°
120° 119° lie _ ^
115
117°
Figure 76. Principal crushed and brolfen stone quarries in California ; numbers
refer to table 46.
desert regions of eiistern and southern California. These, bodies to-
gether underlie about 40 percent of the State's area and are largely
or wholly of Mesozoic age. Batholiths commonly consist of numerous
individual bodies of various granitic rock types, with contrasting col-
ors, textures, and mineral composition. The two great batholiths of
California are exposed mostly in mountainous areas, but the main
granite quarries lie about their peripheries or in outlying smaller
masses, so that the quarries are as close as possible to major transporta-
tion routes to centers of consumption. Over wide areas of the State,
the exposed granitic rocks are so deeply weathered or highly fractured
as to be unsuited to the purposes outlined above. In the Los Angeles
396 MINERAL AND WATER RESOURCES OF CALIFORNIA
area, for example, little or none of the granitic rock exposed in the
nearby Santa Monica or San Gabriel Mountains is sufficiently unshat-
tered or unweathered to be quarried as crushed stone in large tonnages,
and all granitic stone must be brought to the Los Angeles area from
quarries in Riverside, San Diego, and San Bernardino Counties, 45 to
100 miles away. Disintegrated and shattered granitic rock, known
commercially as decomposed granite, or "DG" is much used in southern
California as aggregate base, low-quality paving material, and fill.
In California, granitic rock, has been quarried mainly for use as
dimension stone and riprap, but the quarry waste has been a source
of crushed stone for local uses.
The following granite quarries were active in 1964 : near Rocklin,
Placer County; Logan, San Benito County; the Jurupa Mountains
and vicinity. Riverside and San Bernardino Counties; and near El
Cajon, San Diego County.
Decoinfosed granite
Weathering may decompose the feldspar and ferromagnesium min-
erals in granitic rock, and convert once-sound rock in situ to a weak,
relatively friable mass of quartz grains, clay, and partially decom-
posed grains of feldspar and ferromagnesian minerals. Granite that
has been shattered by fault action is particularly susceptible to de-
composition by weathering. Weathering in sedimentary deposits
of granitic debris may render the stone unsound for use as aggregate
and if sufficiently advanced, convert the deposit to the equivalent of
decomposed granite.
As an extremely low-cost material employed in relatively non-
exacting uses, decomposed granite can rarely be economically hauled
farther than a few miles to the site of use. Therefore, it is used
extensively only in those sections of California where it occurs near
metropolitan areas, especially the Los Angeles and San Diego areas.
Basalt and related rocks
In commercial usage, and in this discussion, the term "basalt" is
applied to any of the dense, fine-grained, dark-gray or black volcanic
rocks. The term ordinarily includes rock types that geologists clas-
sify as dacite, andesite, basalt, trachyte, or latite.
Basaltic rocks are characteristically hard, tough, and durable, so
are best suited for use as aggregate, railroad ballast, and riprap.
Some types of crushed basaltic rock are well suited for use as artifi-
cially colored roofing granules.
Basaltic rocks are extensively exposed in many localities in Cali-
fornia. In the northeastern part of the State, Tertiary and Quater-
nary basaltic rocks are exposed for luuidreds of square miles in the
Modoc Plateau and form tlie most extensive occurrences. A number
of smaller areas, measurable in tens of square miles or less, occur
scattered in the Sierra Nevada and Mojave Desert provinces in the
northeastern portion of central and southern California. Little ba-
saltic stone is obtained from these areas because of their remoteness
from the main centers of use, but some has been quarried for local
construction projects and for railroad ballast.
Less extensive occurrences in the Coast and Peninsular Ranges are
the sources of most of the basaltic stone produced in the State. No-
MINERAL AND WATER RESOURCES OF CALIFORNIA 397
table quantities of basaltic stone are produced near Napa, Marin
County; Novato, Marin County; Orinda, Contra Costa County; Cor-
delia, Solano County; and Jucumba, San Diego County.
Limestone and marble
Carbonate rocks are abundant and commercially important in
California (see section on Limestone, dolomite, and lime products,
including cement ) .
In the stone industry the term limestone is applied to many types
of rock that contain a high percentage of calcium carbonate, although
large proportions of other substances also may be present. They also
commonly contain clay, silt, and sand grains. A high percentage of
clay commonly weakens carbonate rock, and makes it unfit for use
as stone ; a high content of sand grains or silica may make carbonate
rock too hard to be prepared for use economically.
The tenn "marble" is applied to any carbonate rock that will take
a high polish and includes various dense types of limestone and dolo-
mite. The term is also loosely applied to coarsely crystalline carbonate
rocks. Tlie classification of carbonate rock either as limestone or
marble therefore is determined largely by its use. Stone from many
California deposits, for example, has been used both as limestone
(e.g., in the sugar industry) and as marble. Nearly all of the crushed
carbonate stone produced in California is classified as limestone.
For use as stone, carbonate rock should be physically sound, dense,
and relatively pure. Carbonate stone that is strong, tough, and
durable is well suited for use as concrete aggregate, road metal, rail-
road ballast, and riprap. A pure-white color also is desirable in
carbonate stone to be used for granules in built-up roofing, and various
colors are desirable in granules to be used for terrazzo.
Most of the carbonate stone produced in California in recent years
has been used primarily for its chemical properties, and has been con-
sumed in the cement, lime, agricultural, and various other process
industries. Eelatively smaller tonnages have been produced for use as
crushed and broken stone primarily as by-products of cement company
operations.
Occurrences of carbonate rocks are extensive and widespread in
California. Deposits are especially numerous in the western Sierra
Nevada province, the northeastern portion of the Klamath Mountains
province, the Great Basin, and Mojave Desert provinces in south-
eastern California ; in the Coast Ranges, mainly south of San Fran-
cisco, and in the Peninsular and Transverse Range provinces of
southern California. The ages of these deposits range from Precam-
brian to Miocene.
Sandstone
Sandstone is a clastic sedimentary rock composed of particles mainly
in the size range of about one-fourth to one-hundredth of an inch in
diameter. Some sandstones consists almost wholly of quartz grains,
but most sandstones are feldspathic and some contain a high propor-
tion of ferromagnesian minerals. The strength and durability of
sandstone are mainly determined by the type of material that cements
the grains together. Only well-indurated sandstone, cemented with
silica or calcite (rather than with the weaker cements, clay or iron
oxide) , is suited for use as ci-ushed and broken stone.
398 MINERAL AND WATER RESOURCES OF CALIFORNIA
Most of the sandstone that occurs in California is very friable, but
some is sufficiently durable to be used for riprap, railroad ballast,
Portland cement, concrete aggregate, and bituminous aggregate.
Virtually all of the sandstone in California occurs in formations
that lie within the age range of Jurassic to Quaternary. Commonly,
the older sandstones are harder and stronger than the younger ones,
hence are better suited to use as crushed and broken stone.
Sandstone is extensively exposed in most of the western and central
parts of the State, but sandstone for use as crushed and broken stone
has been produced mainly in the San Francisco Bay area at quarries
in Marin and Contra Costa Counties.
Miscellaneous stone
In addition to the four main categories described previously, many
varieties of rock types have been quarried throughout California and
are grouped under the heading of "Miscellaneous stone". Significant
production is obtained from conglomerate, greenstone, slate, tuff, and
metavolcanic rocks.
Conglomerate is clastic sedimentary rock containing abundant frag-
ments of pebble size or larger in a matrix of sand and finer-grained
materials. Conglomerates show various degrees of induration which
depend largely on the nature and amount of cementing material — clay,
calcium carbonate, iron oxides, or silica — in the matrix.
In California, the principal source of conglomerate for use as
crushed and broken stone is a body of well-indurated conglomerate
within the Mesozoic or older Catalina Schist at Pebbly Beach, Santa
Catalina Island, Los Angeles County. This deposit has been worked
for many years, and considerable tonnage has been hauled by barge
to the mainland for use as riprap and harbor stone in the Long Beach
area.
Greenstone is a general term applied by geologists to basic or inter-
mediate volcanic rocks that contain abundant green secondary min-
erals. In the stone industry, the term is applied also to a variety of
fine-grained green rocks, including arkosic sandstone, graywacke, im-
pure quartzite, and various pyroclastio rocks.
Rocks classifiable as greenstone in this broader sense are moderately
abundant in many parts of California, but relatively small tonnages
are used as crushed and broken stone. Many occurrences of green-
stone are outside the range of economic haulage to main centers of
use, and much of the more readily available greenstone is of inferior
quality.
Much of the crushed greenstone is employed for uses in which a
green color is specifically desired, such as for naturally colored roofing
granules. Physically sound greenstone also may be used for aggre-
gate, ballast, riprap, or fill, if it is available economically.
Some of the most extensive occurrences of greenstone in California
are in the Franciscan Formation, in the northern and central Coast
Ranges, and in the upper Palezoic Calaveras Formation and the
Jurassic Amador Group along the west flank of the Sierra Nevada.
Much of the green pyroclastic sedimentary rock quarried in Kern
County since World War II for roofing granules could be classed as
greenstone.
MINERAL AND WATER RESOURCES OF CALIFORNIA 399
Slate is a thinly foliated metamorphic rock composed essentially of
muscovite (sericite), quartz, and graphite, all in grains of micro-
scopic or submicroscopic size. Slate is formed by compaction and
partial recrystallization of shale, is commonly dark colored and
moderately hard.
Slate is desired mainly for use as dimension stone (see section on
Dimension stone). Its chemical inertness, resistance to weathering,
and flat particle shape make crushed slate a desirable material for
roofing granules and filler dust.
Extensive exposures of slate of the Jurassic Mariposa Formation
occur along the western flank of the Sierra Nevada. Minor bodies
of slate, mostly of low quality, occur in pre-Tertiary metamorphic
rocks at) several scattered localities in the State.
The State's principal source of crushed and pulverized slate is the
Chili Bar mine. El Dorado County, which has been active since 1962.
Here the slate is mined in extensive underground workings and is
used for roofing granules and filler dust.
The term "^w^" embraces pyroclastic volcanic i-ocks, most of
which would be classed as rhyolite or dacite tuffs or tuffaceous sedi-
ments. Most tuffaceous rocks are only moderately hard, although on
exposure to air they commonly harden appreciably. As many tuffs
are attractively colored and workable, they have been extensively
used for building stone (see section on Dimension stone) . Because of
its softness, tuffaceous rock is unsuited to most uses of crushed and
broken stone but it is extensively used in the production of colored
roofing granules.
Extensive bodies of light-colored tuffaceous rocks occur in the
Tertiary volcanic section at many localities in California. Pink and
buff-colored tuff in the Valley Springs formation along the west
flank of the Sierra Nevada, and highly colored Miocene tuffaceous
sedimentary rocks near Randsburg in Kern County, are quarried and
crushed for use as naturally colored roofing granules.
Dark dense inetavoUanic rocks are excellent sources of riprap,
crushed stone and roofing granules. Quarries are active in San Diego,
San Diego County; Corona, Eiverside County; and Clayton, Contra
Costa County.
Resource Potential
The market for crushed and broken stone will continue to grow in
California to keep pace with the growth of the State. The demand
has been primarily for stone used in public works and, therefore, can
fluctuate widely from year to year. ^Vliile it appears that reserves are
adequate at developed sources, the press of urbanization threatens
many a quarry. Sources of stone for riprap are constantly being
sought by contractors.
Selected References
Bowles. Oliver, 1039, The stone industries, 1st ed. : New York, McGraw-Hill Book
Co., 519 p.
, 1955, Stone, in Mineral facts and problems : U.S. Bur. Mines Bull. 556,
14 p.
California Division Highways, 1960, Standard specifications : State of California
Dept. of Public Works, Div. of Highways, 390 p.
Davis, L. E., 1963, The mineral industry of California : U.S. Bur. Mines Minerals
Yearbook, preprint.
400 MINERAL AND WATER RESOURCES OF CALIFORNIA
Jenny, Hans, and others, 1951, Minerals nseful to California agriculture : Califor-
nia Div. Mines Bull. 155, 148 p.
Logan, C. A., 1047, Limestone in California : California Jour. Mines and Geology,
V. 43, p. 175-357.
Pit and Quarry Handbook — anmial publication of Pit and Quarry Publications,
Inc., Chicago, Illinois.
U.S. Army Corps of Engineers, 1952, Design of miscellaneous structures, break-
waters, and jettie-s : Preliminary Engineering Manual, Civil Works Construc-
tion, Pt. CXXIX, Chap. 4.
U.S. Bureau of Mines, Minerals Yearbooks [Stone].
STONE, DIMENSION
(Bv H. B. Goldman, California Division of Mines and Geology, San Francisco,
Oalif.)
Dimension stone production is among the oldest and largest of the
mineral industries of California ; commercial quarries were operated
as early as 1854 at Monterey and Point Reyes. Until the early 1900's
the production of dimension stone, mainly for use in buildings, paving,
and curbing, greatly exceeded that of crushed stone, but, since then,
the dimension stone output has dwindled while production of crushed
stone has increased many fold. The development of steel-frame build-
ings, which require comparatively little stone, and the introduction of
concrete, which is much less expensive and more conveniently used
than stone, combined to cause this decline.
The term "dimension stone" is applied to natural stone that is cut
to definite size and shape and includes cut, carved, and roughhewn
blocks of building stone, paving blocks, curbing, flagging, and cut and
polished monumental stone.
The recorded production of dimension stone in California from
1887 to 1964, totals approximately 58 million dollars, as shown in
fig. 77. In 1964 dimension stone valued at approximately 2.1 million
dollars was produced in the State. This stone was used principally
for monumental and building stone. Rock types quarried in 1965
were granite, light-colored volcanics, siliceous limy shales, mica schist,
.slate, and quartzite.
Dimension stone is subdivided by uses into building stone, monu-
mental stone, paving stone, curbing, and flagging. One of the prin-
cipal uses of dimension stone is as a construction material. Included
in this category is stone in any form that constitutes a part of a struc-
ture. Whereas building stone formerly was a basic construction ma-
terial, its present function is largely ornamental. Building stone is
marketed as rubble, rough building stone, ashlar, and cut or finished
stone.
Specifications of Rock Used for Dimension Stone
Only a small portion of the rock that comprises the earth's crust
can satisfy the exacting specifications for most dimension stone. Free-
dom from cracks and lines of weakness is essential. Uniform texture
and grain size together with an attractive color are generally required.
The rock must be free from such minerals as pyrite, marcasite, and
siderite, which oxidize upon Aveathering to cause deterioration or sur-
face staining. A rock that splits easily in 1 or 2 planes is desirable.
Many rocks, particularly granites and sandstones, split in some direc-
tions with greater ease than in others.
MINERAL AND WATER RESOURCES OF CALIFORNIA
401
$3,000
2.600
2.200
in
o:
-^ 1 .800
-I
o
a
u.
o
!» 1 .400
o
z
<
m
3
O
J 1.000
600-
200
c
<
o ea)
c c :2
Post World War 11
construction boom
Inc reasi ng use of
building stone on homes
and small industrial
bui Idi ngs
o
CM
o>
— p-
o
o
o
in
CO
en
OJ
in
CO
Figure 77. California dimensiou stone production, 1887-1963.
Rock Used as Dimension Stone in California
Granite and related rocks
Granite, defined geologically, is a medium- to coarse-grained crys-
talline rock that consists essentially of potassium feldspar, subordi-
nate sodic feldspar, and quartz. In the stone industry the term
"granite" is used more broadly to refer to various intrusive igneous
rocks with granite textures, and even some metamorphic rocks with
gneissic textures. Such igneous rocks as syenite, granite, granodio-
rite, quartz monzonite, diorite, and gabbro, which range in color from
light to dark and in composition from acidic to basic, connnonly are
referred to commercially as "granites".
Granite has comprised api^roximately 75 percent of the total dimen-
sion stone produced in California. In 1963, dimension stone granite
valued at $1,564,271 was produced in the State. Principal sources of
this and other dimension stone types are shown on figure 78.
Granitic rock underlies about 40 percent of California's land area
and occurs mostly in the large bodies known as the Sierra Nevada and
Southern California batholiths, and in smaller bodies exposed in the
Klamath Mountains and in the desert regions of the State.
402
MINERAL AND WATER RESOURCES OF CALIFORNIA
123
EX PLANAT I ON
Sran i te
1 . Roc Klin
2. Raymond
3 . Academy
4. San D lego ' B lacK'
5. San D lego ' Light Grey'
117°
116°
Figure 78. Principal sources of dimension stone in California.
Quarries in the Sierr-a Nevada hatholith. — Quarries in the Sierra
Nevada batholith have yielded approximately half of the granite
dimension stone, and about 40 percent of all the dimension stone
produced in California. The most productive districts have been at
Raymond, Madera County; Eocklin, Placer County; and Academy,
Fresno County. Smaller areas were active at Folsom, Sacramento
County; Porterville, Tulare County; Nevada City, Nevada County;
and Susanville, Lassen County. The quarries have been located mainly
on low rounded outcrops in the foothill area where the granite was
exposed at the surface, or as residual boulders. The periods of great-
est activity were 1889-1895, 1903-1905, and 1920-1930.
MINERAL AND WATER RESOURCES OF CALIFORNIA 403
The principal source of g-ranite in California has been the Raymond
district in Madera County. This district which was active mainly from
1888 to about 1943, has a total production valued at about 10 million
dollars. Granite is quarried from a broad exfoliated dome about TOO
feet in diameter. The oldest and most productive of the quarries, that
of the Raymond Granite Co., was acquired in 1953 by the Cold Spring-
Granite Co. of Minnesota and was still active in 1965.
Granite similar to that quarried at Raymond has been quarried in
Placer County from an area that extends from Rocklin to Newcastle.
Since 1863, granite valued at well over 3 million dollars has been pro-
duced from this district. Quarrying has been confined to the gently
rolling plain, approximately 6 miles long and 1 to 2 miles wide, that
extends from Rocklin to Penryn. In 1965, the Union Granite Co.
operated a quarry near Loomis.
Granite dimension stone valued at more than $650,000 has been pro-
duced in the Sierran foothills 1 mile northeast of Academy in Fresno
County. In this district a dark-colored augite gabbro-diorite crops
out as residual surface builders and as massive ledges underlying low
rounded hills. Nine quarries in all have been worked in a 100-acre
area. In 1964 the Raymond Granite Co. operated a quarry in this
area.
Granite valued at $740,000 has been produced in Tulare County
from three quarries in the foothills east of Porterville and Exeter.
Quarries in the southern Califoiviia hatholith.— In San Diego,
Riverside, and San Bernardino Counties the various bodies of granitic
rock, knoAvn collectively as the southern California batholith, are
sources of dimension stone. The production of granite in San Diego
County from 1898-1963 amounted to approximately 3 million dollars.
Two types of granite have been quarried in the country, a pale-gray
granodiorite and a "black granite,"' which includes such rock species
as hornblende gabbro, norite, and quartz-biotite gabbro. The "black
granite'' is in demand for use in monuments and building fronts be-
cause of its pleasing black color, fine-grained texture which permits a
high polish, and its resistance to weathering. However, the "black
granite'' is unusually hard and tough and therefore more costly to
quarry and finish than most other California granites.
Most of these "black granite" quarries are in residual boulder de-
posits, whereas the light-gray granite is quarried mainly from massive
rock. Distinct joint sets and a poorly developed sheeting structure
characterize the massive exposures. The joints intersect at right
angles and are spaced from 1 to 10 feet apart. The sheeting surfaces
dip gently and generally are parallel to the slope of the land surface
and are irregularly spaced from 6 inches to 6 feet apart. Such fea-
tures are rarely observed in residual bouldery deposits. The boulders
have formed chiefly from weathering through expansion and subse-
quent breaking apart by disintegration.
The principal dimension stone districts in San Diego County are
near Lakeside, Escondido, and Vista. Since 1888, more than 40
quarries have been opened. Fifteen quarries have been active for
various periods since 1953, and four were being worked in 1963. The
most ])roductive operations in 1963 were those of Escondido Quarries
and National Quarries near Escondido. The stone is used for monu-
ments and for making surface plates.
404 MINERAL AND WATER RESOURCES OF CALIFORNIA
Sandstone
Sandstone is a consolidated sedimentary rock composed mostly of
mineral or rock fragments that range in size from -^^r to 2 mm. The
most common cementing materials are iron oxide, calcite, silica, and
clay. The predominant mineral grains in most sandstones in Cali-
fornia are quartz, feldspar, and mica. Some sandstones are composed
almost entirely of qnartz grains ; other sandstones contain 33 percent
or more of fragments of dark-colored rocks and minerals and are
known as gray wacke.
The usefulness of a sandstone as dimension stone depends largely
upon the nature of the cementing material and degree of cementa-
tion. Permanence of color is desired in a sandstone. Uniformity in
grain size, however, is a very desirable feature in sandstone. The
ease w^ith which sandstone can be worked, its variety of pleasing
colors, and its ability to harmonize with brick and other building
material makes it one of the most desirable of the building stones.
The principal uses of dimension sandstone are for building stone,
flagging, and curbing. An estimated 4 million dollars worth of sand-
stone has been produced as dimension stone in California since 1887
( Averill and others, 1948, p. 92) .
Sandstone crops out predominantly in the Coast Eanges of northern
and central California and the Transverse and Peninsular Ranges of
Southern California. Almost all of the dimension sandstone has been
produced from Cretaceous formations.
The principal centers of past production were located at Sites,
Colusa County; Graystone, Santa Clara County; Chatsworth, Los
Angeles County; and Sespe Canyon, Ventura County. The main pe-
riod of sandstone production extended from 1888-1919.
The principal source of dimension sandstone in the State has been
the Upper Cretaceous sandstones near Sites in Colusa County. From
1894 to 1914, these sandstones yielded about 1,186,000 cubic feet of di-
mension stone valued at $1,448,000. The Sites locality is in a belt of
interbedded sandstone and shale that extends along the western margin
of the Sacramento Valley from the northern boundary of Colusa
County southward for 20 miles. In the vicinity of Sites massive
sandstone beds, suitable for building stone, are exposed for a dis-
tance of 8 miles in a zone three- fourths of a mile wide. The beds
range in thickness from 4 to 35 feet, dip approximately 50° to the
northeast, and strike northwest. The stone has a blue-gray and buff
color which weathers to light brown, is soft and has an even grain. In
recent years small quantities have been quarried for use in the San
Jose area in Santa Clara County.
Limestone and marble
To the petrologist, marble is a crystalline limestone, but in the stone
industry and in the present discussion the term ''marble'' is applied to
any calcareous rock capable of taking a polish. Some marbles are
composed almost entirely of carbonate minerals; others contain such
impurities as silica and silicate minerals, iron oxide and iron sulfide
minerals, and organic matter. Marble is commonly white, but the
iron oxides impart colors of tan, red, or brown, whereas carbonaceous
matter causes a gray to black color. Verde antique is a greenish rock
composed of serpentine mixed irregularly with calcite.
MINERAL AND WATER RESOURCES OF CALIFORNIA 405
Uniform hardness and high resistance to abrasion are desirable
qualities in marbles to be used for floor tile, sills, or steps. Marble
for exterior purposes should have a low porosity to prevent infiltration
of water which may dissolve or discolor the stone. Marble to be used
for monuments should present a distinct contrast between chiseled
and polished surfaces. The principal uses of dimension marble are
as building stone and monumental stone.
Despite its widespread occurrence in California, marble has been
produced commercially in only a few localities, principally in Tuo-
lumne, San Bernardino, and Inyo Counties. From 1887 to 1968 the
total recorded production of marble in California was valued at ap-
proximately 4 million dollars.
In 1965, minor amounts of limestone were produced at quarries in
Tulare, Santa Cruz, and Solano Counties mainly for use as rubble.
The Columbia district near Sonora, Tuolumne County, has been the
principal source of marble in California. From 1904 to 1942 this
district yielded 255,000 cubic feet of marble valued at $700,000. In
recent years, the marble has been used as crushed stone.
The marble in the Columbia district occurs as irregularly shaped
masses of dolomite in metamorphosed limestones of the Calaveras
Formation of late Paleozoic age. The limestones are exposed in a
belt, approximately 25 miles long and 1 to 5 miles wide, trending
roughly northwest. The bedding is generally indistinct and steeply
dipping. The marble is a dense, fine-grained dolomite that takes a
fine polish. The stone weighs 169 to 182 pounds per cubic foot and has
a compressive strength of 25,000 pounds per square inch. The stone
most commonly quarried is white with blue veining. A buff stone with
reddish veining also was produced.
From 1896 to 1950, several localities in San Bernardino County
yielded 185,388 cubic feet of dimension stone marble valued at $343,076.
The main periods of activity were from 1902 to 1909 and 1936 to 1941,
The bulk of the early production came from Slover Mountain, near
Colton, where a recrystallized limestone of probable Paleozoic age
occurs as roof pendants in granitic rocks. The poorly defined lime-
stone strata which strike N. 70° E. and dip 45° E. are more than 2,000
feet thick. These beds are now quarried for use in cement.
Slate
Slate is a fine-grained rock produced by the regional metamorphism
of clay or shale. Pressure and heat cause the shaly material to partly
recrystallize to platy, micaceous minerals in parallel orientation. The
cleavage thus produced is sufficiently well developed to allow easy
splitting of the rock and is the feature of greatest economic importance.
The predominant minerals in slate are muscovite, quartz, chlorite,
and carbonaceous matter.
Approximately $700,000 worth of slate dimension stone has been
produced in California since it was first produced in 1880. Peak
years were in 1903 and 1906 when approximately one million square
feet a year were produced. The output held firm through 1910, but
since has been erratic. Small quantities of dimension slate are pro-
duced at Chili Bar and Mariposa in the Sierra Nevada.
Most of the slate production in California has been obtained from
the Jurassic Mariposa Formation which is exposed in the western
406 MINERAL AND WATER RESOURCES OF CALIFORNIA
foothill belt of the Sierra Nevada in Mariposa, Tuolumne, Calaveras,
Amador, El Dorado, and Placer Counties. The Mariposa Formation
originally consisted of shales with minor amounts of interbedded
sandstones and conglomerate. Near the close of the Jurassic Period,
the formation was folded and locally intruded by granitic rocks, and
the shaly material recrystallized into slates and phyllites. The pro-
ductive slate quarries in California are in a slate-bearing belt that
trends northwest from Calaveras to El Dorado County for approxi-
mately 65 miles, and ranges from 1 to 3 miles in width. The schist osity
strikes northwestward and dips steeply to the northeast, irrespective
of the attitude of the original bedding.
Basalt and related r,ock types
In commercial usage and in the discussion to follow the term
"basalt" is applied to any of the dense, fine-grained, dark-gray or black
volcanic rocks, including some that geologists refer to under the more
specific names of dacite, andesite, latite, and trachyte, as Avell as basalt
in the strict sense. All of them have similar physical properties. The
light-colored volcanic rocks are discussed below with the miscellaneous
group.
In California, basalt has been quarried for both paving block and
building stone, and an estimated 3 million dollars worth of basalt
l)aving block has been produced (Averill and others, 1948, p. 98).
Basalts and related rocks are extensively exposed in many localities in
the State. Tertiary and Quaternary basaltic rocks are exposed for
hundreds of square miles in the Modoc Plateau, Sierra Nevada, Mojave
Desert, Coast Ranges, and Peninsular Ranges provinces.
Past production of basalt centered about a score of operations in
the counties immediately north of San Francisco — Marin, Sonoma,
Napa, and Solano.
The periods of peak production years were 1887 to 1891 and 1906 to
1913. More than 50 individual quarries were active from 1864 to
1913. No dimension basalt is presently quarried in California.
Miscellaneous stone
Embraced in the general designation of ''miscellaneous stone" is
a wide variety of rocks, other than those already discussed, that com-
monly are attractive enough to be used as dimension stone. These in-
clude light-colored volcanic rocks, mica schist, and siliceous limy shale.
The important characteristics of these rocks are color, natural appear-
ance, durability, and workability. The colors ordinarily are pleas-
ing shades of off-white, yellow, cream, buff, and pink. The stone
should be easily quarried, soft enough to split by hand or by a block-
splitting machine, yet durable enough to Avithstand weathering. Most
of the rocks in this group occur as layered rocks with natural partings
along bedding planes or along planes of schistosity.
In California, the principal uses of these miscellaneous stones are
as building stone (ashlar, rough block, and rubble) and as flagging.
The Pelona Schist in Los Angeles County, and siliceous shale of the
Monterey Formation near Carmel in Monterey County were quarried
as early as 1927. These and other operations were active intermit-
tently on a minor scale until about 1950, when the building boom
created a new demand for stone. By 1963, the value of the annual
production of miscellaneous dimension stone in California had in-
MINERAL AND WATER RESOURCES OF CALIFORNIA 407
creased to $1,109,980. The bulk of production lias been from the
sedimentary rocks of the Monterey Formation and from the Pelona
Schist.
Monterey ^"Shale"''. — Fine-grained siliceous limy sediments of the
Miocene Monterey Formation crop out in the southern Coast Ranges,
the Transverse Ranges, and the Peninsular Ranges. The rocks are
thinly bedded, dip at low angles in many places, and range from off-
gray to buff-brown in color.
In 1965, the most productive building stone operation in California
was at the site of a former diatomaceous earth operation of the Great
Lakes Carbon Corp. in the Palos Verdes Hills of Los Angeles. The
Palos Verdes Stone Division of this company has directed activities on
their 1,000-acre holdings since 1953 when the building stone production
began.
In Tepesquet Canyon east of Santa Maria in Santa Barbara County,
a light-buff' to cream, thinly-bedded limy siltstone member of the
Monterey Formation has been quarried since 1939. A buff-colored
siliceous shaly limestone has been quarried since 1927 near Carmel in
]\Ionterey County, but by 1964 production had ceased.
Pelona Schht. — A dark-gray, iron-oxide stained quartz-mica schist
of the Precambrian ( ? ) Pelona Schist has been quarried since 1927 at
several localities north of Saugus, Los Angeles County.
Light-colored volcanic rocks. — Rhyolite tuff of the Miocene Valley
Springs Formation has been quarried in the foothills of the Sierra
Nevada since the early 1850's. A buff-colored rhyolite tuff' has been
quarried at several localities near Placerville, El Dorado County,
since 1948.
Banded, light -gray and purple flow rocks of the Pliocene Sonoma
Volcanics have been quarried at several localities near Glen Ellen in
Sonoma County since 1928. The rock is a banded riebeckite rhyolite
that splits readily along well-defined and closely spaced jDarting planes
which are usually stained with brown limonite.
Quartzite. — A red, iron-oxide stained quartzite is quarried intermit-
tently in small tonnages at Suncrest, San Diego County.
Field .stone. — Throughout the State, an undetermined amount of
rock is picked off the ground without any quarrying or other treat-
ment. These rocks are used for garden landscaping and occasionally
as veneer. Among the rocks thus used are schist, mariposite, pumice,
wollastonite, and basalt.
Resource Potential
The outlook for expansion of the dimension stone industries is fair.
The market for monumental stone has been growing, and the merits
of using natural Iniilding stone are being increasely recognized by
architects, builders, and the general public. However, future develop-
ment of deposits in California will continue to be restricted by the
competition from foreign and eastern United States sources.
Selected References
Anbury, L. E.. 1006, Tlie structiu-nl and industrial minerals of California: Cali-
fornia Div. Mines Bull. .3S, 412 p.
Averill, C. V., King, C. R., Symons, H. H., and Davis, F. F., 1948, California
mineral production for 194G : California Div. Mines Bull. 139, p. 92.
408 MINERAL AND WATER RESOURCES OF CALIFORNIA
Bowles, Oliver, 1939, The stone industries: New York, McGraw-Hill Book Co.,
1st ed., 519 p.
Galliher, E. AV.. 1932, Geoloji-y and physical proijerties of building stones from
Carmel Valley, California : California Div. Mines Rept. 28, p. 15-41.
Goldman, H. B., 1957. Stone, dimension, in Mineral commodities of California:
California Div. Mines Bull. 176. p. 591-60G.
Hoppin, R. A., and Norman, L. A.. Jr., 1950, Commercial '"black granite" of San
Diego County : California Div. Mines Spec. Rept. 3, 19 p.
Logan, C. A., 1947, Limestone in California : California Jour. Mines and Geology,
V. 43, p. 175-357.
STRONTIUM
(By Cordell Durrell, Department of Geology, University of California, Davis,
Calif.)
Strontium and strontium compounds are used in many ways in small
amounts. Among these are caustic soda refining, ceramics, depila-
tories, desulfurizing steel, dielectrics, well-drilling muds, getter alloys,
greases, luminous paint, plastics, rubber fillers, coatings for welding
rods, chemicals, and in the production of red pyrotechnics as in signal
flares, tracer bullets, fireworks, and warning fuses.
Strontium occurs in only two minerals of commercial importance —
strontianite (SrCOs), and celestite (SrS04). The former is most de-
sired because of ease in processing it.
Many countries produce strontium minerals in small quantities.
U.S. imports come principally from Mexico and Great Britain. Free-
world production in 1963 was 16,800 tons. The United States is re-
ported to have imported 16,232 tons in the same year. California
deposits have been worked from time to time but their total contri-
bution has been small compared to U.S. consumption.
The strontium minerals commonly occur in veins associated with
other valuable minerals, but mostly they are found in association with
sedimentary rocks, notably limestone and dolomite. In California
they occur in the sediments of long extinct lakes, mostly in association
with clay rocks and volcanic ash deposits.
Occurrences in California
Five of the six known strontium deposits in California are in San
Bernardino County and the other is in San Diego County. All are
in the desert regions. Four, including that in San Diego County, are
celestite. The remaining tw^o, both near Barstow, are strontianite.
Their locations are shown in figure 79.
South end of Death Valley
Celestite occurs as lenses and concretions in middle Tertiary sedi-
mentary rocks at the north end of the Avawatz Mountains; salt and
gypsum are associated minerals. The geologic structure is complex,
and the steeply dipping celestite-bearing beds occur at intervals for
several miles along the strike. Most of the celestite rock is quite im-
pure. The largest celestite body is 2,000 feet long and has a maximum
thickness of 12.7 feet. Numerous other bodies are very much smaller.
Access to the region is difficult.
MINERAL AND WATER RESOURCES OF CALIFORNIA
409
strontium deposits
1 . S outh end ot Dea th Valley
2. Solomon strontianite deposit
3. Ross strontianite de pos i t
4 . Lud I 0*
5 . Bristol Dry Lake
6. Ocot I I I o-F ish Creek fash
L_L_
Figure 79. Strontium in California.
Bristol Dry Lake
Concretions of celestite occur in the upper 3 feet of the playa sedi-
ment along the south margin of the Bristol Dry Lake west of the
Amboy to Twentynine Palms road. They are most abundant in sec.
6, T. 4 N., R. 12 E., S. B. where about 18 acres were exposed by
ploughing in 1942. Concretions exposed by deflation are also present
east of the road, and are also reported along the north shore of the
playa. The celestite concretions may occur elsewhere around the
playa.
Ocotillo-Fisli Creek Wash
Celestite-bearing rock occurs capping hills 9/2 miles south of
Ocotillo, just north of Fish Creek "Wash and by the road to the gypsum
mine. The pure celestite occurred as a lens or lenses in gypsum but
now consists only of remnants on the hill tops. Much of the original
bodies have been mined, and no continuation or extension of this deposit
in any direction is to be anticipated.
Ludlmo
Celestite rock occurs as concretions and beds in lacustrine clays,
volcanic ash, and limestone of Tertiary age in sees. 29 and 30, T. 8 N.,
R. 7 E., S.B. at the south base of the Cady Mountains, 8 miles northwest
of Ludlow, San Bernardino County. The celestite is exposed in a
number of isolated outcrops that extend along the strike of the sedi-
mentary beds for a distance of 6,300 feet. The maximum reported
thickness of celestite-bearing rock is 112 feet distributed through a total
thickness of 350 feet of beds. Single celestite beds range up to 2 feet
in thickness and zones up to 30 feet thick are as much as 25 percent
celestite rock. The beds dip about 50° S. so that most of the deposit is
concealed. Some celestite has been mined.
©7-164 o— 66 — pt. I-
-27
410 MINERAL AND WATER RESOURCES OF CALIFORNIA
Solomon strontianite deposit
A strontianite deposit known as the Solomon deposit is in the east
end of the Mud Hills, north of Barstow, in sec. 20, T. 11 N., R. 1 W.,
S.B. Strontianite occurs principally in bedlike deposits in two strati-
graphic units one of which is 10 to 15 feet thick, and the other 20 to 30
feet thick. It also occurs in veins and concretions. The deposits are
in clay and volcanic ash, and the geologic structure is complex. The
strontianite rock is distributed over half a square mile and is dissemi-
nated in such a way that no significant concentrations occur.
Ross strontianite deposit
Another deposit known as the Ross strontianite deposit is about a
half mile from the Solomon deposit, in the NE14 sec. 30, T. 11 N., R.
1 W., S.B. Strontianite occurs in nodular concretionary beds 0.1 to 1.5
feet thick and is distributed over about 7 acres. The beds dip to the
north at 20 to 40°. The deposit extends eastward where it is concealed
by younger rocks. .
Selected References
Durrell, Cordell, 19.53, Geological investigations of strontium deposits in southern
California : California Div. Mines Spec. Rept. 32, p. 1-48.
U.S. Bureau of Mines, Minerals Yearbook, v. 1, 1963, Chapter on Strontium
minerals. See also other volumes in this series.
SULFUR
(By A. R. Kinkel, Jr., and G. N. Broderick, U.S. Geological Survey,
Washington, D.C.)
Sulfur is a nonmetallic element that is found widespread in nature
in both the free state and in combination with other elements. Its
largest single source is from deposits of native sulfur associated with
salt domes. Other sources include metallic sulfides, hydrogen sulfide
gas associated with natural gas and petroleum, concentrating plants
and smelters treating sulfide ores, oil refineries, coal-burning plants,
and deposits of gypsum and anhydrite.
Sulfur has many and varied uses. Its principal use is for the pro-
duction of sulfuric acid, an acid that is used so extensively by modern
industry that it is considered an index of a nation's economic activity.
The largest sulfur consuming industry in the United States is the fer-
tilizer industry. Sulfur is also used in large amounts by the chemical,
paint and pigment, iron and steel, rayon and film, and petroleum indus-
tries. These consumers use the sulfur in acid form. The paper in-
dustry uses large quantities of sulfur for sulfite pulp, and the nisecti-
cide and rubber industries use large amounts of elemental sulfur. The
consumption pattern of sulfur and sulfuric acid in California is com-
plex because of the diversified agricultural and industrial enterprises.
United States production of sulfur in all forms in 1964 amounted to
7.1 million long tons, of which 5.2 million long tons came from deposits
associated with salt domes in Texas and Louisiana mined by the
Frasch hot-water process. Free-world production in 1964 totaled an
estimated 20.85 million long tons, an increase of 8 percent over 1963
production.
Moderate quantities of sulfur have been produced intermittently
from sources in California. The State's total production, however,
MINERAL AND WATER RESOURCES OF CALIFORNIA 411
is insufficient to meet the needs of its numerous sulfur-consuming
industries, and out-of-state sources (Frasch sulfur from Texas and
Louisiana) supply most of the elemental sulfur consumed in Cali-
fornia. Production in California has come from the following sources :
native sulfur, pyrite, smelter gases, and from sour-natural and refinery
gases as a by-product of petroleum refining. Locations of these
sources are shown on figure 80.
Native Sulfur
The Leviathan mine in Alpine County has been by far the largest
producer of native sulfur in California. Sulfur occurs as veins and as
an impregnation of completely opalized fine-grained andesite tuff of
42'-
41"-
I TRINITY
(
EXPLANAT ION
'%7"
■^^\
, ^' S I S K 1 1 Y o\u^
If VSQUTHERN
K-tiAMApy ,^
v ^2 L 1 L <- V t"'
I 1 suaktaV i-^ \-. X^^ .
^.__.^. <V !
""^"_^^^ Plumas ^^,
J-.l ^ L(-<5-f'tf^NEVADAl\
, SH^TA
'- L,
124°
^NOMA^NAlV' >,
■ ii/ •> •V'
i^K^y
\2i\ ";
Francjscii \
BORA^oJ-S^y
,-^AU'lNf^.
NATIVE SULFUR
1 . Auschwitz (Seward)
2. Benton
3. Cha Ik Mtn. (Canary Hill)
4. Champion S i I I iman ite , jnc
5. Cos Range
6. Coyote Mtn.
7. Elgin
8. Ful I Moon
9. The Geysers
10. Graciosa Ridge
1 1 . Horseshoe Bend Mtn.
12. Last Chance Range
(Crater and Gulch groups)
13. Leviathan
14. Mount Shasta
15. Sear les Borax Lake
IB. Sulfur Mtn.
17. Sulphur Bank
1 B. Sunset Oi I 0 istr ict
19. Supan
BY-PRODUCT
SULFUR AREA
Arroyo Grande
Los Ange les
San Franc isco Bay
X
PYRITE MINES
I . A I ma and Leona
2 . Ir on Mounta in
3 . Spencev i I le
4 . Da i ry Farm
5. Copper Queen
6. Val ley View
''"^n
AsANTicO >\MERe«;p-
37° — N£SJk^ (c\, ; \ /\
,SA>X V
\\ ^FRESNrt
S \ X '18°
TUOLUMNE ;\mon6\ 4-38°
/ <>
X
36
■+
vpENITOl
I.
hop >.
xMONTEREY^'S
\\
4—
I n y o >c> \
<$>.
san'
^
.cj-
'^
\
n-
ai6°
N
^'.'
36°
n
35°+
lOBISPO
1.^ ■
\
^15°
T
34°+
121°
(KERN
ISPU "V
'— *£BARBARa| ^'\'f^ \y,OS ANGELESi
MOJAVE
SAN BERNARDINO
\
DESERT
V
NGEsV
50
I I I
100
_J
— ^— Y^^"
SIDE (
J
V
■^^33°
JIMPER'*
iALTON
•■BOUGH|b^
116°
115°
Figure 80. Sulfur in California.
412 MINERAL AND WATER RESOURCES OF CALIFORNIA
Tertiaiy age about 100 feet thick. The tuff is enclosed in andesitic
mud flows and breccias. Sulfur was introduced along faults together
with considerable pyrite (Pabst, 1940). A small but rich copper de-
posit was mined in the upper part of this sulfur deposit in the 1860's.
Some early production for sulfur was recorded from the leviathan
mine, but the main production was from 1953 to 1962 to supply sulfuric
acid for recovery of copper at Yerrington, Nevada.
Smaller amounts of native sulfur have been produced from mines
m Inyo, Colusa, Kern, Lake, and Imperial Counties, and from a few
other counties ( Branner, 1959) .
Sulfur From Pyrite
Pyrite has been mined to produce sulfur at several mines in Cali-
fornia, and sulfur has been an important by-product recovered m
treating low-grade massive sulfide copper ore. The principal producer
of sulfide ore has been the Iron Mountain mine of the Mountain Copper
Co, in Shasta County. The Alma and I^ona mines in Alameda County
and the Spenceville mine in Nevada County produced smaller amounts.
Sulfur w^as not recovered in treating most of the copper-bearing mas-
sive sulfide ores in California.
Production of sulfur from sulfide ore up to 1964, as far as records
are available, is shown in table 47, furnished by the U.S. Bureau of
Mines.
Table 47. — Pyrite and, pyrrhotitc production from tchich sulfur was recovered
Long tons of
Location: sulfide ore
Iron Mountain mine, Sliasta County 4, 500, 000
Alma mine, Alameda County 156,500
Leona mine, Alameda County 87, 600
Spenceville mine, Nevada County 150, 000
Others (Dairv Farm mine. Copper Queen mine, Valley VieW
mine) 90,000
Total 4,984,100
In treating low-grade pyritic copper ores it has been economic in
some cases to roast the ore first to remove the sulfur, and to leach the
copper from the residue (calcines) . The copper is recovered as copper
sulfate, w^hich is a readily marketable product. The iron residues con-
tain some sulfur after roasting, and it is a finely ground product that
would have to be sintered before further treatment. Both of these
features have made the residue unattractive as an iron ore.
In recent years it has been more economical for sulfur users in
California to buy Frasch process (native) sulfur. Although most of
the copper mines contain large amounts of sulfur in sulfides, there is
thus little probability that sulfide deposits in California can be mined
for their sulfur content in the foreseeable future.
By-Product Sulfur and Sulfuric Acid
By-product sulfur })roduction from oil refineries in California
began in 1937 when Standard Oil Co. of California reported produc-
tion of hydrogen sulfide from its El Segundo refinery in JjOS Angeles
MINERAL AND WATER RESOURCES OF CALIFORNIA 413
County. Elemental sulfur production from hydrogen sulfide was first
reported in 1949 by the Hancock Chemical Co., Los Angeles County.
By 195-i more than half of the sulfur-equivalent produced in California
was derived froui tlie treatment of sour or sulfurous crude oils and
gases, and waste-acid sludges from petroleum rehneries (Lydon, 1957).
With the exception of the Union Oil Co. of California rennery m the
Arroyo Grande area, which began production in 1955, the refineries in
California are centered in the Los Angeles and San Francisco Bay
areas. In 196;], according to the I'.S. Bureau of Mines, six California
plants (two in Contra Costa County, three in Los Angeles County, and
one in San Luis Obispo County) recovered elemental sulfur from sour-
natural and rehnery gases as a by-product of petroleum refining.
Sulfur compounds are recovered from stack gases at the American
Smelting & Refining Co: smelter at Selby in Contra Costa County,
where sulfur dioxide has been converted to sulfuric acid since 1937,
and liquid sulfur dioxide production was first reported in 1953.
Resource Potential
Production of native sulfur and of pyrite in California is feasible
only when it can compete profitably with Frasch sulfur. Oil refineries
will continue to yield increasing amounts of by-product sulfur. Liquid
sulfur dioxide and sulfuric acid will continue to be obtained from
smelter gases by the American Smelting & Refining Co. at Selby, but
the possibility of production from other smelters in California does
not seem promising at the present time.
Gypsum, a sulfur-bearing mineral that is abundant in California,
is sold for agricultural use. It is not likely, however, to become a
significant source of sulfur in the near future.
Selected References
Branner, G. C, 1959, Sulfur in California and Nevada : U.S. Bur. Mines Inf. Circ.
7,898, 50 p.
Chesterman. C. W., 1957. Pyrites, in Mineral commodities of California: Cali-
fornia Div. Mines Bull. 176. p. 449-i54.
Espenshade, G. H., and Broedel, C. H.. 1952. Annotated bibliography and index
map of sulfur and pyrites deposits in the United States and Alaska (including
references to July 1, 1951) : U.S. Geol. Survey Circ. 157, 48 p.
Key, W. W., 1965. Minerals for chemical manufacturing — A survey of supply
and demand in California and Nevada : U.S. Bur. Mines Inf. Circ. 8,244, 164 p.
Kinkel, A. R., Jr., and Albers. J. P.. 1951. Geology of the massive sulfide deiwsits
at Iron Mountain. Shasta County, California : California Div. Mines Spec. Rept.
14, 19 p.
Lvdon. P. A., 1957. Sulfur and sulfuric acid. /» Mineral commodities of Cali-
'fornia : California Div. Mines Bull. 176. p. 613-622.
Lynton. E. D., 1938. Sulphur deposits of Inyo County, California: California
Jour. Mines and Geology, v. 34. p. 563-.590.
:Murdoc-h. Joseph, and Webb. R. W.. ItWS. Sulphur, in. Minerals of California :
California Div. Mines Bull. 136. p. 289-290.
Pabst, Adolf, 1938. Sulphur, in Minerals of California: California Div. Mines
Bull. 113, p. 19-20.
. 1940. Cryptocry.stalline pyrite from Alpine County, California : Am.
Mineralogist, v. 25. no. 6, p. 425-431.
Vernon, J. W.. 1950. Sulfur, in Mineral commodities of California : California
Div. Mines Bull. 156. p. 273-275.
, 1950. Sulfuric acid, in Mineral commodities of California : California
Div. Mines Bull. 156, p. 27.5-276.
-, 1951, California sources of sulfur and sulfuric acid, in Minerals useful
to California agriculture : California Div. Mines Bull. 155, p. 129-130.
414 MINERAL AND WATER RESOURCES OF CALIFORNIA
TALC AND SOAPSTONE
(By L. A. "Wright, Department of Geology and Geophysics, Pennsylvania State
University, University Park, Pa.)
Use and Economic Importance
The term "talc" is applied to a mineral species and also to various
commercially valuable aggregates of magnesium silicate minerals.
The mineral talc (Mg3Si40io(OH)o), is extremely soft, flaky in habit,
soapy to the touch, chemically inert, and difficult to fuse. This com-
bination of properties distinguishes it from most other common min-
erals and contributes to its usefulness. Most commercial talcs con-
tain the mineral talc as a prominent constituent, but they commonly
also contain one or more other minerals among which are tremolite
(Ca2Mg5H2(Si03)8), serpentine (a hydrous magnesium silicate),
chlorite (an alumino-silicate of iron and magnesium), anthophyllite
((Mg,Fe)7SisOo2(OH)o), olivine ( (Mg,Fe)oSi04), carbonate min-
erals, and quartz. Depending upon the intended use of the commercial
material, these other minerals may be beneficial or may constitute
impurities.
About 50 percent of the talc now being mined in California is used
as a ceramic raw material and about 9.0 percent is used as a paint
extender. The remaining 30 percent is marketed for a wide variety
of uses, especially as an ingredient in the manufacture of paper and
rubber, a polishing and coating agent in the preparation of rice, siz-
ing in the preparation of textiles, a powder for toilet and pharma-
ceutical preparations, a filler in asphalt, and a carrier for insecticides.
For most of these uses, whiteness of color, both in the ground and
fired state, is required. The degree to which the ground talc will
absorb certain types of greases and oils, contributes to its usefulness
as a paint extender (Lamar, 1952) .
Some of the talc that is used for ceramic purposes, particularly the
manufacture of wall tile, consists almost wholly of the mineral tremo-
lite. In the production of liigh-frequency insulators, which must
have low-electrical conductivity, material composed essentially of the
pure-mineral talc is desired. If suitable for this purpose, the talc
is designated as "steatite."' Talc of steatite or near-steatite grade
commonly is specified for uses that require a soft, smooth, and inert
material. For use as ordinary fillers and insecticide carriers, dark-
grinding talcs that contain several percent iron oxide are acceptable.
The most commonly mined material of this type is a blocky, talc-rich,
but generally impure material known as "soapstone."
Most of the talcs that are sold commercially consist of mixtures
of two or more types of crude materials, and are especially ground
and blended for specific industrial applications. High-quality talcs
mined in California, ground, and sold at the mill are valued in the
range of $34 to $40 per ton. Talcs ground to very fine sizes are mar-
keted at about $80 per ton.
Geologic Occurrence
Talc deposits typically occur in highly deformed terranes in which
bodies of igneous rocks are abundant (Chidester and others, 1964;
Engle and AVright, 1960) . Most talc deposits of commercial interest
MINERAL AND WATER RESOURCES OF CALIFORNIA 415
are associated with magnesium-rich rocks, particularly the magnesian
carbonate rocks, dolomite and dolomitic limestone, and the ultra-
mafic igneous rocks. Mineable concentrations also have altered from
other types of rocks including quartzite, granite, schist, and limestone.
In California, as well as in the United States in general, talc has been
mined mostly from bodies that represent alterations of carbonate
rocks (Wright, 1954). These deposits characteristically contain less
than 1.5 percent iron oxide, reflecting a low iron content of the orig-
inal rock. On the other hand, deposits that have altered from the
ultramafic rocks, principally serpentine, ordinarily contain several
percent of iron oxide, enough to appreciably discolor the product in
either the ground or hred state. Much of such talc can be classified
as soapstone. Talc that is associated with ultramafic rock, therefore,
is generally of less commercial interest than talc that is associated with
carbonate rocks.
Talc bodies of commercial interest are ordinarily tabular to lenti-
cular in shape. They range in length from a few tens of feet to several
thousands of feet and in width from a few feet to a few hundred
feet. Because most talc-bearing terranes are highly deformed, steep
dips are common. Some deposits consist of commercial material from
wall to wall, but masses of waste rock cause many deposits to be diffi-
cult to mine or prohibit their commercial development.
History of Disco\'ery and Development
Talc was first mined in California by jjrehistoric Indians who carved
it into utensils and ornaments. As earlv as the mid-1800's, white
settlers were mining soapstone from deposits along the western foot-
liills of the Sierra Nevada and were using the material in linings
and foundations of furnaces and for building and ornamental stone.
Talc-bearing areas that lie east of the Sierra Xevada and that are
now major domestic sources, were opened in the period 1912 to 1918.
Of special importance was the development of the Talc City mine,
near DarAvin in Inyo County (Page, 1951; Gay and Wright, 1954),
which for many years was the nation's principal source of steatite-
grade talc. Mucli of the talc mined in this deposit has been blocky
enough to be machined into insulator bodies, but such bodies are now
manufactured by molding or extruding ground steatite mixed with a
binder. Steatite from the Talc City mine was much in demand par-
ticularly during World War I, when foreign sources of high-priority,
block V talc were cut off.
From 1916 to the mid-1930's, the Talc City mine, together with the
Western mine in southern Inyo County (Wright and others, 1953;
Wright, 1954a) and the SilverLake mine in northern San Bernardino
County (Wright, 1954b) were the principal sources of talc in Cali-
fornia. During this period, the total production of talc in the State
rose from about 9,000 to about 20,000 tons per year. This output was
used mainly in the paint, cosmetic, and insulator industries.
During the period 1933 to 1943, the use of talc as a major ingredient
in the manufacture of wall tile became widespread. In this period,
also, steatite-grade talc was found to be a necessary ingredient in the
manufacture of higli-frequency electrical insulators for certain types
of electronic equipment. Because this grade of talc was then again
416 MINERAL AND WATER RESOURCES OF CALIFORNIA
in short supply, it was classified as a critical mineral for a several-
month period in 1942 and 1943. Spurred by these two uses and by the
groAvth of industry and population on the Pacific Coast, talc produc-
tion in California had reached 65,000 tons per year in 1943. This
output Avas obtained mainly from mines in the region that extends
from the Inyo Mountains southeastward through the Death Valley
area to the Nevada line. The Talc City, Western, and Silver Lake
mines continued in operation, and numerous other mines were ex-
panded or placed in production. Of these others, the White Moun-
tain mine in the Inyo Mountains (Page, 1951), the Death Valley,
Grantham (Warm Spring), Eclipse, Monarch, Superior, Tecopa
(Smith), Acme, and Excelsior mines in the southern Death Valley-
Kingston Range region (Wright, in press, 1966), and the Yucca Grove
mine north of Baker, San Bernardino County (Wright, and others,
1953), have been the most productive and continuously worked.
The post-war building boom, and the resulting demand for paint and
wall tile, caused a continued increase in talc production in California.
Production of about 120,000 tons was reached in 1951. Since then the
production rate has been in the general range of 100,000 to 130,000 tons.
Several additional mines have been opened in the post-war period.
These are widely scattered through the State, but most of them lie
east of the Sierra Nevada in the established talc-producing areas. The
most productive of these more recently developed mines are the Eureka
mine in the northern Inyo Mountains, the Omega mine in the central
Kingston Range, and the Rainbow and Sheep Creek mines in the south-
ern Death Valley area (Wright, 1966, in press) .
The mining of soapstone in the western foothills of the Sierra
Nevada has continued, on a small scale, to the present. About 20
properties have been worked, but most operations have been short-
lived.
In 1963 about 114,000 tons of talc and soapstone was mined in Cali-
fornia to bring the overall production to nearly 3 million tons since
the early 1900's. The 1963 output of high-quality talc was obtained
from 12 properties in San Bernardino County, and 11 in Inyo County.
Most of the established mines continued in operation. Soapstone was
quarried from two properties in Amador County, one in El Dorado
County, and one in Los Angeles County (U.S. Bureau of Mines,
Minerals Yearbook for 1963) .
United States as a Source of Talc
Since the beginnings of the talc mining industry, the United States
has constituted the principal source and market of the material. In
1963, a total of 671,000 tons of talc was mined in the L^nited States.
This was nearly one-fifth of the world's total output. About 92
percent of the domestic product was consumed within the United
States, and about 26,000 tons of talc was imported mainly from Italy
and France and used in the cosmetic and pharmaceutical trades.
California's Rank in U.S. Production of Talc
For many years California has ranked second to New York State
in tonnage of talc produced. Until the early 1950's, the State was
the source of almost all of the steatite-grade talc produced in the
MINERAL AND WATER RESOURCES OF CALIFORNIA 417
United States, but now Montana far outranks California in both
production and reserves of such talc. The decline, in California, of
the production of steatite-grade talc has been dwarfed by the increase
in the production of other types of talcs, particularly those that supply
the building industry of the Western States. For these markets, the
talc produced in California can be supplied at a lower cost than talc
from most other domestic sources. Thus a continuing and growing
market seems assured for these products.
Occurrences in California
Smithem Death Valley-Kingston Range region
The largest and presently most productive source of high-quality
commercial talc in California is a group of deposits that occurs in a
belt about 75 miles long that, as shown in figure 81, extends from
southern Death Valley eastward to the Kingston Eange near the
California-Nevada line (Wright, 1966, in press). These deposits
occur in an ancient (Precambrian) unit termed the Crystal Spring
Formation which consists of marine strata and the dark igneous rock,
diabase. The latter was introduced, mostly as sills, soon after the
strata were deposited. Most of the talc bodies have formed along the
margins of a single, very extensive sill and are alterations of carbonate
strata. The mineralized zone, thus formed, originally extended over
2,000 square miles or more, but severe and much later deformation
has caused the talc-bearing terrane to be thoroughly faulted, and much
of the talc has been removed by erosion following uplifts. Thus, the
talc bodies are now very discontinuous. They commonly constitute
zones of weakness along which faulting has been localized, so that
deposits pinch and svrell abruptly.
The talc body at each of the more productive mines is 1,000 or more
feet long. Some are as much as 5,000 feet long. Most of them are 10
to 20 feet in average width. As nearly all of the mining has been done
within 500 feet of the surface, the down-dip extent of much of the
larger deposits remains undetermined. The commercial talc in these
bodies ranges in composition from mostly talc to mostly tremolite. In-
dividual bodies commonly contain two layers, one talcose and one
tremolitic.
Inyo Moiiffitains and nortliern Panamint Range
The talc deposits in the Inyo Mountains and northern part of the
Panamint Range, both in Inyo County, have yielded nearly all of the
steatite-grade and pharmaceutical-grade talc mined in California.
These deposits generally are much smaller and more irregular than
those in southern Death Valley-Kingston Eange region. The largest
bodies are about 500 feet long and 50 feet in maximum width; most of
them are only a few tens of feet long and a few feet wide. Most are
lenticular to very irregular in shape.
They occur as replacement bodies in Paleozoic sedimentary rocks
and, locally, in granitic rock of Mesozoic age. Most of the talc in
these deposits is an alteration of dolomite, but some has altered from
quartzite, limestone, and quartz-rich igneous rocks. The commercial
talc in most of these deposits consists almost wholly of the pure
418
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANAT ION
1 . McLean
2 . Psc i f ic Minera Is
3. Eureka
4. Blue Star
5. While Eag le
6. Gray Eagle
7. Hi Iderman
(Giay Eag le )
Ubehabe
9. White Mountain
10. Talc City
n . Death Val ley
12. Montgomeiy
13. Giantham
(Death Va I ley )
14. Eel ipse
15. Mammoth
16. Monarch. Pleasanton
<^nd Ibex
17 Western and Acme
18. Booth
19. Tecopa (Smith)
20. Omega and Vulcan
(Har r y Adams )
21 - t«ce Is I or
22 . Super i or . Pongo,
Wh I te Cap and
Saratoga
23 . Ra i nbow and
Ca I lente
24. Sheep CreeK
25. S I Iver Lake
26. Yucca Grove and
Ca Imas i I
27. ICatj
UT"
Figure 81. Talc mines in California.
mineral. Chlorite, tlie only other nuignesinm silicate present, is
abnndant in deposits that have altered from igneous rocks.
Sih)e7^ Lake-Yucca Grove area
A small group of deposits, including those at the Silver Lake mine
and occurring in the ]5aker- Yucca Grove area of north-central San
Bernardino County, form part of a complex of metamorphic and igne-
ous rocks which is presumed to be of Precambrian age. These de-
posits apparently represent layers and lenses of dolomite that have
been thoroughly altered to rock composed mostly of talc and tremolite.
These deposits also are very discontinuous. Those that have been
mined average about 10 feet in width; two such bodies commonly
MINERAL AND WATER RESOURCES OF CALIFORNIA 419
parallel each other and are separated by a 15-foot thickness of waste
rock. The largest of these deposits are abont 500 feet long and most
or all of them appear to bottom within 300 feet of the surface. Al-
though the mined material is coarser grained than that obtained from
the southern Death Valley area, it is marketed for the same general
uses.
Westerii foothills of tlie Sierra Nevada
The talc deposits that occur in the western foothills of the Sierra
Nevada and that have altered from bodies of ultramafic rock are prob-
ably much more numerous than the deposits east of the Sierra Nevada.
But, they have been mined much less extensively, because the talc
typically contains several percent of iron oxide and thus cannot be
used for most of the purposes to which the low-iron talcs are put. The
talc bodies in the Sierra Nevada foothills are characteristically lentic-
ular and rarely exceed 50 feet in width and 400 feet in length. Only
deposits that can be mined by open-pit methods and lie close to rail
facilities have proved profitable, as the mind material is much lower in
value and much less in demand than the low-iron talcs from the de-
posits described above.
Resource Potential
The tonnages of high-quality talc that remain to be mined in Cali-
fornia are difficult to estimate. By far the largest resources exist in
the deposits of the southern Death Valley-Kingston Range region.
Although in most mines only a few tens of thousands of tons are
blocked out in advance of mining, studies of the geologic environments
indicate that many millions of tons of talc remain in this region. The
tonnage that will be eventually recovered will depend upon the maxi-
mum depths to which individual mines can be worked at a profit, the
efficiency of the mining operations, and the prices that these talcs will
command in the future. Conservatively estimated, at least 2 million
tons of talc or about 20 year's supply at the present rate of production
appears to be recoverable. The eventual recovery may well exceed
this figure by 2 or 3 times.
The talc resources in the Inyo Mountams-northeni Panamint Range
region and in the Silver Lake- Yucca Grove area are much smaller
than those of the southern Death Valley-Kingston Range region. Most
of the deposits have been mined, both laterally and downdip, to points
where they pinch out or are too thin to be mined profitably. De-
posits, comparable in size to those already mined, are certain to exist
at shallow depths and unexposed, but discovering them will be difficult
and expensive.
The resources of relatively dark, high-iron talcs in California ap-
pear to be measurable in many millions of tons. Although these de-
posits remain to be studied in detail, they seem capable of supplying
the markets for this type of talc indefinitely.
Future explorations for talc in California should center about the
known talc-bearing areas and be aimed at the discovery of extensions,
either downdip or lateral, of known deposits or mineralized zones.
As the main talc-bearing zone in the southern Death Valley-Kingston
Range region is everywhere at about the same stratigraphic position.
420 MINERAL AND WATER RESOURCES OF CALIFORNIA
drilling programs could be planned on a stratigraphic basis and in
areas where the Crystal Spring Formation, which contains the talc,
is believed to lie beneath a thin cover of younger rock.
The deposits in the Silver Lake- Yucca Grove area also seem to lie at
a uniform stratigraphic position. Here, too, drilling for extensions
of the known deposits is recommended if economically^ feasible.
Selected References
Chidester, A. H., Engel, A. E. J., and Wright, L. A., 1964, Talc resources of the
United States : U.S. Geol. Survey Bull. 1,107, 61 p.
Engel, A. E. .!., and Wright, L. A., 1909, Talc and soapstone, in Industrial min-
erals and rocks : Am. Inst. Mining Jletall. Petroleum Engineers, 3d ed., p.
835-850.
Gay, T. E., Jr., and AVright, L. A., 1954, Geology of the Talc City area, Inyo
County, Map Sheet no. 12 : California Div. Mines Bull. 170.
Lamar, R. S., 1952, California talc in the paint industry : California Jour. Mines
and Geology, v. 48, p. 189-199.
Page, B. M., 1951, Talc deposits of steatite grade, Inyo County, California : Cali-
fornia Div. Mines Si>ec. Rept. 8, 35 p.
Wi-ight, L. A., 1950, Geology of the Superior talc area, Death Valley, California :
California Div. Mines Spec. Rept. 20, 22 p.
, 1954a, Geology of the Silver Lake deposits, San Bernardino County, Cali-
fornia : California Div. Mines Spec. Rept. 38, 30 p.
1954b, Geology of the Alexander Hills area, Inyo and San Bernardino
County, Map Sheet no. 17, of Jahns. R. H.. ed.. Geology of southern California :
California Div. Mines Bull. 170.
-, 1956, Talc and soapstone: California Div. Mines Bull. 170, p. 023-634.
Wright, L. A., in press, Talc deposits of the southern Dealth Valley-Kingston
Range region, California : California Div. Mines and Geology Spec. Rept.
(1966).
Wright, L. A., Stewart, R. M., Gay, T. E., Jr., and Hazenbush, G. C, 1953, Mines
and mineral deposits of San Bernardino County, California : California Jour.
Mines and Geology, v. 49, p. 197-216 and tab. list, p. 168-173.
THORIUM
(By J. R. Evans, California Division of Mines and Geology, Sacramento, Calif.)
Thorium is a heavy, soft, ductile, and radioactive metal. It was
discovered by Berzelius in 1828 on analyzing a mineral (thorite) from
Lovo Island, opposite Bevik, Norway, and named for Thor, the Scan-
dmavian god of thunder.
The metal has not been produced in California, and the State needs,
as well as that of the United States, as a whole, are fulfilled mainly by
imports of monazite from Australia and Malaysia. Monazite-bearing
black sand from Florida provided about 20 percent of domestic con-
sumption in 1964. Only 1,800 tons of monazite, valued at $155,000,
were imported in 1964, as compared with 6,434 tons, valued at $777,000
in 1963. The reason for the decrease in imports was the closing of
the monazite mine at Steenkampskraal, Cape Province, South Africa
in mid-1963, after completion of an 8,000 short ton (of 5 percent +
ThO-2 monazite) contract with American Potash and Chemical Corp.
From 1961 to 1963 this mine provided 78 percent of United States
imports of monazite.
By far the most important use for thorium is as a 3 percent additive
to magnesium in order to form a low-density, high-temperature, high-
strength alloy for high-speed aircraft and missiles. Thorium nitrate
MINERAL AND WATER RESOURCES OF CALIFORNIA 421
is used ill incandescent gas mantles in lanterns for camping and by our
armed services and accounts for about 30 percent of thorium consump-
tion. Koughly 10 percent of thorium consumption is for catalysts in
the petroleum and chemical industry, in tungsten electrodes for inert
arc-welding, and as nonconsumable electrodes in vacuum arc-melting
of refractory metals. A very small amount of thorium is used in
nuclear reactors for power plants, but there may be increased con-
sumption in the near future, possibly in California.
The California Department of Water Resources and the Atomic
Energy Commission are considering a seed-blanket reactor, using a
thorium fuel cycle, as a source of power for transporting and pump-
ing water long distances and over mountain ranges with as much as
2,000 feet of relief. If the reactor is located near the coast, it may
include a sea-water to fresh-water conversion unit.
Monazite is a cerium group rare-earth metal phosphate containing
as much as 10 or 12 percent thorium oxide. There are several other
thorium-bearing minerals such as thorite (thorium silicate), pyro-
chlore (niobate of cerium group rare-earth metals, calcium and sodi-
um, with some titanium, fluorine, and thorium), and thorianite (oxide
of thorium and uranium), but at present monazite is more abundant
and can be mined at lower costs than the other minerals.
Because monazite is physically durable, chemically stable, and has a
fairly high specific gravity, it is a typical detrital mineral common in
placer deposits of beach and river sand. It is particularly abundant
in local alluvial material adjacent to, or underlain by biotite-rich
granitic and metamorphic rocks in which monazite occurs as a minor
constituent. Thorium-bearing minerals also occur in veins cutting
some granitic and metamorphic rocks, such as those in Idaho, Mon-
tana, and Colorado.
At Mountain Pass, San Bernardino County, monazite occurs in
dolomite-rich areas along the borders of the intrusive Sulfide Queen
carbonate body adjacent to its contact with Precambrian schist and
gneiss. The monazite also is Precambrian. The thorium oxide con-
tent of monazite ranges from 1 to 3 percent. Thorite is found with
hematite, goethite, sericite, chlorite, quartz, and carbonate minerals
in shear zones, and also in some carbonate veins in the Mountain Pass
area. Analyses of some vein material show as much as 6 percent Th02.
In the Music Valley area. Riverside County, thorium-bearing xeno-
time (yttrium group rare-earth metal phosphate) and monazite occur
in biotite-rich areas in the Precambrian Pinto Gneiss. Semiquantita-
tive spectographic analyses of samples of gneiss show that Th02 con-
tent is mostly below 0.50 percent, but one sample contained 1.2 per-
cent of ThOo. A highly radioactive sample of xenotime and monazite-
bearing gneiss from the U-Thor deposit was analyzed chemically. It
showed a 0.5 percent ThOo content, and a 7.3 percent ThOo content
after mechanical concentration of xenotime and monazite.
Nearly all the rare-earth metal-bearing minerals in California con-
tain some thorium, and the reader who is interested in more informa-
tion about the geologic occurrence of thorium should refer to the rare-
earth section in this bulletin.
Under present marketing conditions, most deposits of monazite
and other thorium-bearing minerals generally are not of high enough
grade to compete with imports from foreign deposits. However,
422 MINERAL AND WATER RESOURCES OF CALIFORNIA
foreign deposits may be depleted and/or imports cut off because of
war or other factors, and exploration for monazite should continue,
particularly in California where thorium fuel cycle reactors may be
used. Granitic and metamorphic rocks tliat show a radioactive anom-
aly should be sampled and examined for thorium oxide content. Beach
sand and dune sand, as well as gruss derived from weathering of
granitic rocks should also be examined, because placer deposits such
as those in Florida and Idaho appear to be a major source of thorium
(monazite) in the United States.
Selected References
Baroch, C. T., 1962, Thorium : U.S. Bureau Mines, Minerals Yearbook, 1963, 6 p.
, 1964, Thorium : Eng. Min. Jour., v. 166, no. 2, p. 132-134.
Evans, J. R., 1964, Xenotime mineralization in the southern Music Valley area.
Riverside County, California : California Div. Mines Si}e<?. Kept. 79, 24 p.
Frondel, Clifford, 1956, Mineralogy of thorium, in Contributions to the geology of
uranium and thorium by the United States Geological Survey and Atomic
Energy Commission for the United Nations International Conference on Peace-
ful Uses of Atomic Energy, Geneva, Switzerland, 1955 : U.S. Geol. Survey Prof.
Paper 300, p. 567-579.
• , 1958, Systematic mineralogy of uranium and thorium : U.S. Geol. Survey
Bull. 1,064, 400 p.
Olson, J. C, Shawe, D. R., Pray, L. C, and Sharp, W. N., 1954, Rare-earth mineral
deposits of the Mountain Pass district, San Bernardino County, California :
U.S. Geol. Survey Prof. Paper 261, 75 p.
Olson, J. C, and Adams, J. W., 1962, Thorium and rare-earths in the United
States : U.S. Geol. Survey Mineral Inv. Resource Map MR-28.
Paone, James, 1960, Thorium : U.S. Bur. Mines Bull. .585, p. 863_872.
Troxel, B. W., 1957, Thorium, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 635-640.
Twenhofel, W. S., and Buck, K. L., 1956. Geology of thorium in the United
States, in Contributions to the geology of uranium and thorium by the United
States Geological Survey and Atomic Energy Commission for the Unite<l
Nations International Conference on Peaceful Uses of Atomic Energy. Geneva,
Switzerland, 1955 : U.S. Geol. Survey Prof. Paper 300, p. 559-566.
U.S. Bureau of Klines Commodity data summaries, 1965. Thorium, ji. 1,50-151.
Wilhelm, H. A., 1961, Thorium, in Hampel. C .A.. Rare Metals Handbook : New
York, Reinhold Pub. Corp., p. 536-558.
TIN
(By C. H. Gray, Jr., California Division of Mines and Geology, Los Angeles,
Calif.)
The usefulness of tin is based upon its easy fusibility, malleability,
resistance to corrosion, readiness to alloy with other metals, and its
attractive silver color. No completely adequate substitute has been
found for its major use as a protective coating for other metals. Most
of the tin consumed in the United States is used in the production of tin-
plate, solder, bronze, brass, and babbitt, and in tinning; small quan-
tities are used in metallic forms, miscellaneous alloys, and chemicals.
Cassiterite (Sn02), is the principal tin-bearing mineral of com-
mercial importance, but, in a few localities, tin has been recovered
from lode deposits that contain the complex sulfides stannite, cylin-
drite, and teallite. Tin minerals are widely distributed throughout the
world, but in only a few areas are the deposits large enough to be
profitably mined.
Primary tin deposits show a characteristic genetic relation to silicic
igneous rocks, particularly to granite pegmatites. Bolivian deposits
MINERAL AND WATER RESOURCES OF CALIFORNIA 423
are associated with quartz monzonite. Most tin veins are hi^h-tem-
perature hydrotliernial deposits and are 'believed to have formed under
high pressures. Wood tin, a nodular variety of cassiterite, occurs in
rhyolite flows. As cassiterite is extremely resistant to alteration and
has a high specific gravity, it is easily concentrated in placer deposits.
Tin was first discovered in California in the Temescal district,
Riverside County, probably in 1853. In 1869, a 15.34-ton shipment
of ore to San Francisco was said to have yielded 6,895 pomids of tin
(Page and Thayer, 1945, p. 1). However, the first production of
record was in 1891. Ore was mined during 1891-1892 and in 1928-
1929. Estimates of total production from the district range from 113
long tons of tin (Segei-strom, 1941, p. 543) to 130 long tons (Page
and Thayer, 1945, p. 2).
A property in Trabuco Canyon, Orange County, was explored in
1916 in search of tin, but no production was recorded (Segerstrom,
1941, p. 534). Cassiterite was identified in 1940 in ore from the Eve-
ning Star copper-tungsten ])rospect, San Bernardino County, and ex-
tensive underground prospecting was done from early 1941 through
late 1944, when the mine was closed. Several small shipments of ore
and concentrates were made, with a probable total tin content slightly
less than 2 tons.
Tin was discovered in the Gorman district, Kern County, in 1940,
and during the period 1943-1945, the Meeke-Hogan mine yielded 6.70
short tons of ore equivalent to 2.64 tons of tin. Tin mining was re-
newed in July 1963 and has continued on a small scale to date (July
1965) . According to the operator, this operation has yielded about 47
short tons of concentrates ranging from 35 percent to 65 percent metal-
lic tin and averaging about 58 percent.
During 1964, free- world mine output was about 146,000 long tons of
tin, while consumption of primary tin was about 168,000 long tons.
The gap between production and consumption was offset by 29,000
tons sold by General Services Administration during 1964. United
States consumption in 1964 was estimated as 59,000 tons of primary
tin and 23,000 tons of secondary tin ; some observers believe consump-
tion will be 100,000 tons by 1975. Although the United States con-
sumes about 40 percent of the free-world tin output, the production
from its few scattered tin deposits is insignificant. In 1964, United
States production consisted of small quantities of tin in concentrate
produced at the Meeke-Hogan mine in California and as a by-product
of molybdenum mining in Colorado.
The total California tin production that has been reasonably well
documented is equivalent to about 140 long tons of tin metal, calcu-
lated on the basis of 100 percent recovery from concentrates.
Occurrences in California
Cassiterite, the only tin-bearing mineral of commerical importance
known to occur in California, has been reported at numerous localities
in 15 counties, but in only about half of these localities has its j^resence
been substantiated. Most of the localities are in southern California
(Segerstrom, 1941, p. 549-552; Bedford and Johnson, 1946). Stan-
nite (Cu2FeSnS4) occurs at the Pacific Limestone Products quarry
424 MINERAL AND WATER RESOURCES OF CALIFORNIA
near Santa Crnz and at the Thompson lead-silver mine, Darwin dis-
trict of Inyo County. Three mines in the State, representing three
geologic-geomorphic provinces, have recorded production of tin.
The Temescal mine and several neighboring properties, which to-
gether constitute tlie Temescal tin district, are confined to an area of
approximately 15 square miles within the Peninsular Ranges province,
about 11 miles soutliwest of Kivei-side. Mesozoic quartz monzonite
contains tourmaline-quartz veins and pipelike masses in which cas-
siterite occurs as disseminations and as bunches and stringers, and in a
few of which recoverable amounts of cassiterite have been found.
Tourmaline veins in Mesozoic quartz latite porphyry also contain
traces of tin.
According to Page and Thayer (1945, p. 8) , the average width of the
veins, including spotted tourmaline rock and silicified rock, probably is
1 to 2 feet ; in places a few are 15 to 20 feet wide. Most of the veins
are less than 1,000 feet long and are discontinuous, although one vein
system is about 4,800 feet long. Their downward extent is not known,
but the Cajalco vein was folloAved to a depth of 690 feet and was not
bottomed.
Maps of the mine indicate that two cassiterite-bearing ore shoots in
the Cajalco vein yielded the entire production; one was about 70 feet
and the other 160 feet in strike length. The larger one had a dip
length of about 240 feet (Page and Thayer, 1945, p. 15-16, figs. 8, 11).
Assays indicate that almost all of the veins contain 0.03 to 0.1 percent
tin; the Cajalco vein averages about 0.15 percent of tin. The ore
that was milled is reported to have averaged in the range of 2 to 5
l)ercent SnO^ ( Page and Thayer, 1945) .
The Meeke-Hogan mine and several neighboring tin-bearing prop-
erties are in the Gorman district of southern Kem County, near
the boundary of the Sierra Nevada and Mojave Desert provinces, at
the southwest end of the Tehachapi Mountains. These deposits consist
of small cassiterite-bearing iron-rich bodies associated with tactite
bodies which apparently have replaced limestone near the borders of
an intrusive mass of granitic rock. The cassiterite occurs as scattered
grains within the tactite, which is composed principally of limonite,
magnetite, and various contact-metamorphic minerals.
The largest deposit, the Meeke-Hogan, is composed chiefly of two
bodies of tin-bearing limonite gossan. The Avest gossan is about 200
feet in length and has a maximum exposed width of 40 feet, and lenses
out at either end. The east gossan is 100 feet long and as much as 30
feet wide.
According to Wiese and Page (1946, p. 37) the Meeke-Hogan mine
was extensively explored in 1942-1943, including core drilling. Most
of the high-grade ore was obtained from residual boulders exposed
at the surface. Some was mined, by means of shallow pits, from
pockets in limestone. The average grade of these small shipments was
about 40 percent tin. However, exploratory Avork indicated that
reserves of ore in place carried only from 0.1 to 2.0 percent tin (Wiese,
1950, p. 46). During 1963-1965, mining has been from near-surface,
narro^v. high-grade cassiterite zones in limestone between the former
west and east shafts at the Meeke-Hogan mine.
MINERAL AND WATER RESOURCES OF CALIFORNIA 425
Since mid-1964, the California Division of Mines and Geology has
been engaged in a geochemical, geophysical, and geologic study of the
area. In June and July 1965, the U.S. Bureau of Mines in coopera-
tion with the Division core-drilled two sites.
The Evening Star mhie, and other nearby tin-bearing properties,
are about 8 miles north of Cima in the Mojave Desert province in
northeastern San Bernardino County. These are small contact-
metamorphic replacement deposits in dolomite and dolomitic lime-
stone, near an intrusive body of quartz monzonite. The mine has
explored, to a depth of 100 feet, a hematitic pipelike ore body formed
in limestone at the intersection of two fractures. Cassiterite occurs
as disseminated grains, euliedral crystals, and massive aggregates in
tremolite-serpentine-cftlcite rock together with scheelite, chalcopyrite,
sphalerite, pyrite, and magnetite.
Properties otlier than those in the districts mentioned above, and
at which tine has been noted in quantities greater than one pound per
ton of rock sample, include the following : The Lucky Three, Jeanette
Grant, Black Jack, Rocky Point, and Big Blue properties in the
Isabella district, Kerii County ; the Greenback Copper and Iron Moun-
tain properties in the Woody district, Kern County; the American
Flag and Monarch mines in the Elsinore district. Riverside Comity;
and the Atolia tungsten mines, San Bernardino County (Bedford and
Johnson, 1946).
The tin occurrences in California that have been worked or have
attracted attention as possible commercial sources are primary de-
posits. The absence of known concentrations of placer tin in Cali-
fornia is evidence against the former or present existence of exposures
of large vein deposits. There remains the slight possibility of segre-
gations at depth and of sufficient size to be economic. Should such
deposits exist, it seems likely that they will be found in areas of silicic
granitic rocks. The fact that tin occurs at several localities in Cali-
fornia near contacts of quartz monzonite or granite with metamorphic
rocks, or in quartz monzonite, points to such areas as possible prospect-
ing targets. Tin resources in California have not been quantified,
although relatively minor reserves apparently exist in the Meeke-
Hogan mine area.
Selected References
Bedford, R. H., and Johnson, F. T., 1945, Survey of tin in California : U.S. Bur.
Mines Inv. Rept. 3S76, 14 p.
Bedford, R. H., and Ricker, Spansrler, 1949, Investigation of the Hogan tin mine,
Kern County, California : U.S. Bur. Mines Inv. Rept. 4509, 10 p.
Gray, C. H.. Jr.. 1957. Tin, in Mineral commodities of California : California Div.
Mines BuU. 176, p. &41-&46.
Page, L. R., and Thayer, T. P., 1945, The Temescal tin district. Riverside County,
California : U.S. Geol. Survey unpub. rept. 27 p., 13 figs., 2 tables (on open file
California Div. Mines Library) .
Pane, L. R.. and Wiese. J. H., 1945 (19.59), The Evenin? Star tin deix>sit and
adjacent tungsten deposits, San Bernardino County, California : U.S. Geol.
Survey manuscript on file California Div. Mines and Geology, Los Angeles,
17 p., 8 illus.
Segerstrom, R. J.. 1941, Tin in California : California Jour. Mines and Geology,
V. 37, no. 4, p. 531-557.
Wiese, J. H., 1950, Geology and mineral resources of the Neenach quadrangle,
California : California Div. Mines Bull. 153, 53 p.
Wiese, J. H., and Page, L. R., 1946, Tin deposits of the Gorman district, Kern
County, California : California Jour. Mines and Geology, v. 42, no. 1, p. 31-52.
67-164 O— 66^pt. I -28
426 MINERAL AND WATER RESOURCES OF CALIFORNIA
TITANIUM
(By Norman Herz, U.S. Geological Survey, Wa.shington, D.C.)
Intkoduction
Titanium comprises 0.6 percent and is the ninth most common ele-
ment of the continental crust. Its greatest application is as titanium
dioxide in pigments, but its use as a structural metal is increasing at
a much greater rate. The United States consumed about 1.1 million
ions of TiO, in 1962 and 1963, divided (in 1962) as follows: 96.8
percent in pigments, 1.5 percent Avelding rod coatings, 1.4 percent as
metal, and 0.3 percent for other purposes, including as a ferroalloy
and carbide, and in plastics and ceramics (Peterson, 1965).
An increased consumption of about -4 percent a year for the period
1960-1985 is seen for TiOa and about 13 percent a year for 1963-1985
for Ti metal (Fulkerson and Gray, 1964). By the end of 1985, the
domestic consumption of TiO^ pigment is expected to be 1.3 million
tons and Ti metal 100,000 tons.
Titanium dioxide was developed as a pigment for paints because
of its high opacity, its chemical and physical stability, and its low
specific gravity. In 1960, 96 percent of the white paint coverage in
the United States utilized a titanium dioxide base (Fulkerson and
Gray, 1965).
Titanium is the fourth most abundant structural metal, has the
highest strengtli to weight ratio of any of them, shows little change
in physical properties from minus 300°F to 1,000°F, and has the
greatest resistance to corrosion of any common metal or alloy (Schlain,
1964). These properties explain its increasing use in supersonic jet
aircraft, rockets, submarines, desalinazation plants, and elsewhere in
industry where extreme teniperatures or corrosion are major problems.
Rutile (TiOo), and ilmenite (FeTiOs), are the most important
economic minerals of titanium. Anatase (TiOo), and alteration
products of ilmenite are also recovered from some placer deposits.
Both rutile and ilmenite are found in primary or lode deposits in
igneous or met amorphic rocks and in alluvial or eluvial deposits, in-
cluding placers, beach sands, saprolite, and bauxite. The principal
ilmenite deposits, however, are primary, and are associated with
anorthosite-gabbro complexes, whereas most of the world's rutile is
obtained from beach sands. United States ilmenite production is
from anorthosite deposits in NeAv York, saprolite in Virginia, and
beach sands in Florida and New Jersey. Entile is produced from
saprolite in Virginia and beach sands in Florida.
California and United States Production
The earliest attempt to mine titanium ore in California was from
Russ Siding in Soledad Canyon, Los Angeles County, in 1906 and
this failed because of the refractorv nature of the ore (Oakeshoot,
1950, p. 354). The State's largest production was in 1927-1938 when
10,013 tons of ilmenite valued at $150,195 was mined in Los Angeles
County from a beach de])osit in Hermosa and a lode deposit in the San
Gabriel Mountains for the manufacture of white pigment. Outside of
Los Angeles County, ilmenite has only been mined in modern and
MINERAL AND WATER RESOURCES OF CALIFORNIA
427
ancient beach sands at Aptos, Santa Cruz County. Distribution of
titanium deposits is sliown in figure 82.
The total California production is estimated at 15,000 tons, and this
is almost entirely from Los Angeles County (Lydon, 1957, p. 649).
This figure is negligible compared to the United States total of 890,000
short tons of ilmenite and 11,900 of rutile for 1963 alone (Stamper,
1964).
Occurrences in California
Calif orma, Coast Ranges
Ilmenite has been found in black sand deposits with magnetite,
chromite, zircon, garnet, and monazite near Crescent City, Del Norte
Comity, and in black sand layere near Aptos in Santa Cruz County.
The Crescent City sands are similar to the occurrences in southern
Oregon which have up to 8.3 percent ilmenite by weight and 0.5 per-
EX PLANAT I ON
I I men i te I ode de pos i t
®
Ilmenite placer deposit
O
Rutile I ode de pos i t
U7'
Figure 82. Titanium deiwsits in California and types of ore.
428 MINERAL AND WATER RESOURCES OF CALIFORNIA
cent rutile (Griggs, 1945). The Crescent City black sand occurs in
layers and lenses that vary in thickness from a few inches to 42 feet, in
width from a few tens to more than 1,000 feet, and in length from a
few hundred feet to more than a mile.
Black sands on the shore of Monterey Bay, near Aptos in Santa Cniz
County, were Avorked unsuccessfully in 1926-1927 as a source of sponge
iron, titanium, and chromium (Oakeshott, 1950, p. 353). The black-
sand layers occur in long, irregular crescents up to 6 inches in thickness,
50 feet in width, and 100 to 200 feet in length, and contain up to 16 per-
cent TiO- in the form of ilmenite. Economic minerals associated with
the ilmenite are magnetite, chromite, garnet, zircon, hematite, and
some gold and platinum minerals (Lydon, 1957, p. 650). Hutton
(1959) found abundant ilmenite in black sands at Ano Nuevo Creek
about a mile to the northwest of Aptos and at the Pajaro River about
10 miles south.
Mojave Desert
The only known deposit of rutile in the State is west of Barstow and
north of Hodge in San Bernardino County (Wright and others, 1953,
p. 110 of table). The deposit is small and consists of disseminated
rutile crystals that are locally concentrated in layers in a 200-foot
long lenticular quartz body in schist. A test sample was found satis-
factory for the manufacture of electric welding rods in 1942 but the
deposit apparently was never worked.
Transverse Ranges
The most important titanium deposits in California are in Los An-
geles County and include modern beach sands in the Clifton area and
lode and sand deposits in the western San Gabriel Ranges. The lode
ore consists of apatite and ilmenite-magnetite intergrowths in altered
pyroxenite segregations in anorthosite. The ore bodies vary greatly
in form and size, ranging from small irregular veins to large dikelike
lenses, but all are lenticular in outline (Oakshott, 1948, p. 253; Higgs,
1954). Ore also occurs in placers derived from the weathering of the
anorthosite.
About 12 million tons of titaniferous iron ore are estimated to be in
anorthosite that ranges from 5 to 10 percent Ti02 plus several million
tons of 2 to 3 percent TiOj (Peterson, 1965) . Placer deposits in Pacoi-
ma Canyon contain several million tons that range from 2.4 to 30.8
percent TiO^: the placers in San Canyon average about 7 percent Ti02
( Benson and others, 1962, p. 8 ) .
Ilmenite-bearing beach sands between Redondo and Palos Verdes
have been intermittently worked from at least 1927 to 1944. The sands
along more than 3,000 feet of beach average 7 percent ilmenite, and
the richer parts have as much as 60 percent ilmenite (Lydon, 1957, p.
650) . No recent production is known from this area.
Salton Trough
An anorthosite-gabbro complex that may have once been continuous
w^ith the San Gabriel anorthosite, but was displaced about 130 miles
to the southeast on the San Andreas fault, Avas discovered recently
in the Orocopia Mountains, just nortli of the Salton Sea (Crowell and
Walker, 1962). Several large lenticular or veinlike bodies of ilmenite-
magnetite-apatite rock were found northwest of Salton Creek Wash.
MINERAL AND WATER RESOURCES OF CALIFORNIA 429
in the contact area of anortliosite and gabbro. These had been pros-
pected but not mined, and no information is available on the re-
sources of the area (CroAvell and Walker, 1962) .
Appraisal
The titanium resources of the State are not fully known. Further
geologic and geophysical work accompanied by drilling is needed for
the ilmenite placer deposits of Aptos, Crescent City, and Los Angeles
County and for the lode deposits of the San Gabriel and Orocopia
Ranges. Inferred reserves in these deposits are probably sufficient to
support both titanium pigment and metal plants of moderate size. The
rutile of San Bernardino County is not economically exploitable under
present-day conditions.
Selected References
Benson, W. T., Engel, A. L., and Heinen, H. J., 1962, Titaniferous magnetite
deposits, Los Angeles County, California : U.S. Bur. Mines Rept. Inv. 5,962,
40 p.
Crowell, J. C, and Walker, J. W. R.. 1962, Anorthosite and related rocks along the
San Andreas fault, southern California : Univ. California Pubs, in Geol. Sci.,
V. 40, no. 4. p. 219-288.
Fulkerson, F. B., and Gray, J. J., 1964, The titanium industries and their rela-
tion to the Pacific Northwest : Bonneville Power Adm., Econ. Base Study for
Power Requirements, v. 2, pt. 7G, 46 p.
Griggs, A. B.. 1945, Chromite-bearing sands of the southern part of the coast of
Oregon : U.S. Geol. Survey Bull. 94.5-E, p. 113-150.
Higgs, D. v.. 1954, Anorthosite and related rocks of the western San Gabriel
Mountains, southern California : Univ. California Pubs, in Geol. Sci., v. 30, no.
3, p. 171-222.
Hutton, C. O., 1959, Mineralogy of beach .sands between Halfmoon and Monterey
Bays , California : California Div. Mines Special Rept. 59, 32 p.
Lydon, P. A., 1957. Titanium, in Mineral commodities of California : California
Div. Mines Bull. 176, p. 647-654.
Oakeshott, G. B., 1948, Titaniferous iron-ore deposits of the western San Gabriel
Mountains. Los Angeles County, California, in Iron Resources of California :
California Div. Mines Bull. 129, p. 245-286.
Oakeshott, G. B., 1950, Titanium, in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 1.56, p. 352-355.
Peterson, E. C, 1966, Titanium resources of the United States : U. S. Bur. Mines,
Inf. Circ. 8290.
Schlain, David, 1964, Corrosion properties of titanium and its alloys : U.S. Bur.
Mines Bull. 619, 228 p.
Stamper, J. W., 1964, Titanium, in Bureau of Mines Minerals Yearbook, 1963 :
U.S. Bur. Mines, p. 1133-1154.
Wright, L. A., Stewart, R. M., Gay, T. E., Jr., and Hazenbush, G. C, 1953, Tabu-
lated list of mines and mineral deposits in San Bernardino County, in Mines
and mineral deposits of San Bernardino County, California ; California Jour.
Mines Geol., v. 49, 192 p.
TUNGSTEN
(By D. M. Lemmon, U.S. Geological Survey, Menlo Park, Calif.)
Tungsten is an important metal in industrial processes because the
element, its alloys, and its compounds have unique physical and me-
chanical properties including strength, hardness, heat resistance, and
electrical and thermionic qualities. Tungsten metal is light gray,
heavy (specific gravity 19.3), and heat resistant (melting point
3,410° C, highest of the metals) . Pure tungsten metal in wire form, is
430 MINERAL AND WATER RESOURCES OF CALIFORNIA
used in the filament of electric light bulbs and in other lighting and
electronic devices. Much larger quantities of tungsten are used in
combination with other substances, in alloy steels for high-tempera-
ture applications, in nonferrous alloys, in tungsten carbide for cutting
tools, in armor-piercing shells, and in various chemicals for dyes, inks,
and fluorescent lamps. Of the 10,516,000 pounds of tungsten con-
sumed in the United States in 1963, approximately 40 percent was
used in carbides, 27 percent in steel, and 12 percent in nonferrous
alloys (Stevens, 1964).
In nature, tungsten does not occur as native metal, but is chemically
combined in 14 known minerals, of which the commercially important
ones are scheelite (calcium tungstate) and the gradational members
of the wolframite group: ferberite (iron tungstate), wolframite (iron
and manganese tungstate), and huebnerite (manganese tungstate).
Most tungsten ores contain only small proportions of these minerals,
which must be concentrated to 60 to 70 percent of AVOs before utiliza-
tion. The concentrate also must meet low tolerances of such impurities
as tin, copper, arsenic, antimony, bismuth, molybdenum, phosphorus,
sulfur, lead, and zinc, each of which may be injurious for particular
uses. Scheelite forms a gradational series with powellite (calcium
molybdate) and may contain varying proportions of molybdenum and
tungsten. Some scheelite concentrates, especially from contact-
metamorphic ore bodies, contain as much as 5 percent of molybdenum
chemically combined in the scheelite. The molybdenum must be
removed by chemical digestion if a molybdenum-free product is
required.
The principal world sources of tungsten ores are veins, contact-
metamorphic deposits, hydrothermal replacement deposits, stockworks,
and placers. Vein deposits have been the most productive, followed
by contact-metamorphic deposits; veins probably contain the largest
known resources, although potentially very large resources are also
present in the brines of Searles Lake. Pegmatites and deposits of
tungsten-bearing iron and manganese oxide have been worked on a
lesser scale than the other types.
The veins generally have a gangiie of quartz and contain wolframite,
huebnerite, or ferberite, usually with some scheelite, and some contain
only scheelite as the tungsten mineral ; some contain minor proportions
of sulfides and other minerals that may yield by-products. The veins
commonly are found in granitic igneous rocks or closely associated
with granitic rocks, and range from thin seams to layers manj' feet
thick. The content of WO3 in ores mined has ranged from 0.25 percent
to more than 10 percent and has perhaps averaged 0.5 to 1.0 percent.
The vertical range of tungsten-bearing ore shoots is shallow in
many vein deposits; at Atolia, California, ore was followed to a maxi-
mum depth of only 1,100 feet.
Contact-metamorphic deposits contain scheelite in skarn (tactite)
composed of garnet and other silicates formed at places along or near
contacts of granitic intrusive rocks Avith invaded carbonate rocks. The
ores are complex and may yield such by-products as molybdenum,
bismuth, silver, copper, and fluorite. The content of WO3 in exploited
deposits has ranges from 0.25 percent to several percent. Some major
deposits containing millions of tons have been worked to depth without
MINERAL AND WATER RESOURCES OF CALIFORNIA 431
reaching the bottom of the ore, and others have been worked out near
the surface. Contact deposits liave not been as important as veins in
Avorld output of tungsten, but some very large productive deposits of
this type exist in the United States, Canada, Korea, and Tasmania.
The United States has traditionally been the largest consumer of
tungsten, followed by other industrial nations, principally Great
Britain, Germany, France, Sweden, Russia, and Japan. Consump-
tion in Europe generally exceeds that in the United States. United
States cor^sumption reached .a peak of 19 million pounds in 1943-
1944; in the period 1957-1964, annual consumption ranged from 8.5
million (1957) to 13.6 million (1962) pounds (Stevens, 1964), and
was approximately 11.5 million pounds in 1964 (Forbes, 1965).
Only the United States and Russia among the industrial nations
obtain an appreciable portion of their tungsten requirements from
domestic sources. The United States has always imported tungsten
concentrates to meet part of its needs, although the domestic mming
industry has long been sheltered by a tariff, currently $0.50 per pound
of contained tungsten, equivalent to $7.93 per short ton unit of WO3.
Only in 1953-1956, under premium prices guaranteed by the United
States Government, did domestic production exceed consumption
(Holliday and Burke, 1958).
The price of tungsten concentrates fluctuates widely with supply
and demand. Consumption increases markedly during periods of
high industrial actiA'ity and of war, and decreases drastically during
slack periods. The tungsten-mining industry is not instantaneously
adjustable to such wide fluctuations, and the time lag leads to cyclic
oversupply and Inidersupply and to price instability. Prices have
ranged from a low of $2 a short ton unit ^ at the start of this century
to $85 in 1916 during World War I. Following a postwar period of
low demand and distress prices while excess inventories were con-
sumed, quotations increased to $28 during World War II. From
1951 to 1955, in order to create a strategic stockpile, the United States
bought domestic concentrates at $63 per unit of WO3, thus stimulating
the largest domestic production on record. Since 1958, most of the
United States production has come from two mines: Pine Creek, Cali-
fornia, and Climax, Colorado. These were the only producers in
1964 (Forbes, 1965), and their combined output was nearly half as
large as that yielded by almost 600 mines in 1956 (Holliday and
Burke, 1958, p. 1,227) .
In June 1965, the price of foreign concentrates delivered in the
United States had firmed to $27.75, plus tariff of $7.93 per unit, from
a low of $7.75 plus tariff in mid-1963.
China, the leading producer of tungsten concentrates since 1915
when wolframite deposits were discovered there, has contributed about
27 percent of the world output from 1905 through 1964, and the
United States, second largest producer, has contributed 13 percent.
Within the United States, California and Nevada each yielded
about 30 percent of the total domestic output from 1900 to 1957, fol-
lowed in order by Colorado, Idaho, and North Carolina. Some sig-
nificant production (more than 0.1 percent of the cumulative total)
has come from six other states. California reached first in cumulative
1 A short toa unit of WOis is 20 pounds (Vioo of a short ton) and contains 15.862 pounds
of tungsten ; 1 miUion pounds of tungsten are contained in 63,050 units of WO3.
432
MINERAL AND WATER RESOURCES OF CALIFORNIA
pi'odiK'tion since 1958 because of laro:e product ion from tlie Pine Creek
mine while most other deposits in tlie nation were idle. The cumu-
lative production of the ITnited States was derived from many mines,
large and small, but a high percentage of the total came from rela-
tively few deposits. In 1955 and 1956, when United States output was
at its peak, 15 mines accounted for 82 percent (1955) and 90 percent
(1956) of the total output (Holliday and Burke, 1957).
In 1962, the United States (Tovernment held in stockpile concen-
trates containing 161,464,000 pounds of tungsten (Wall Street Jour-
nal, March 26, 1962), an amount roughly equivalent to two-thirds of
total shipments from mines in the United States since 1900 and more
than 8 percent of all tungsten produced in the world to that time.
Shipments of concentrates from California from 1906 to 1957 are
listed in table -18, with approximate value. Since 1957, production
figures for California have l)een withheld to avoid disclosing data held
in confidence, but the larger part of the 37,098 tons of 60 percent WO.h
produced in 1958 to 1963 in the United States came from California.
Table 48. — Shipments of tungsten ore and concentrate from California mines,
1906-57, in short tons of 60 percent WO^
Period
Tons
Value
(thousands)
1906-12
2,226
8,882
4,541
18, 652
26, 871
1 $8C0
1913-19
11,608
1924-38
3,735
1939-46.
25, 317
1947-57
85,808
1906-57
61, 162
127, 268
1 Estimate.
Tmigsten mining in California was started in 1905 with the discov-
eiy of vein deposits rich in scheelite at Atolia, San Bernardino County.
The contact-metamorphic scheelite deposits west of Bishop were rec-
ognized in 1914 and were productive during World War I and inter-
mittently to the present. Hundreds of tungsten occurrences have
been found in California, mostly of the contact-metamorphic type asso-
ciated with granitic rocks of the Sierra Nevada and southern Cali-
fornia batholiths (Stewart, 1957: Bateman, 1965). In a summary re-
view of tungsten deposits of the United States, Lemmon and Tweto
(1962) listed 177 mines or districts in California. Of these, only 36
are known to contain more than 10 tons of metallic tungsten (1,261
short ton miits of WO3) in combined production and reserves; they are
the ones shown on the map (fig. 83) and described briefly in table 49,
keyed by numbers to the map.
Major tungsten resources of California are in the Sierra Nevada,
the Great Basin, and the Mojave 1 )esert geomorphic provinces. Minor
deposits are present in the Transverse Ranges and in the lower Cali-
fornia provinces. A few noncommercial occurrences are known from
the Klamath Mountains and the California Coast Ranges.
Two areas have yielded the largest production : the Bishop district
and the Atolia district. At Bishop, many mines have contributed,
including those of the Pine Creek area, the Tungsten Hills (11), and
the Black Rock mine (5), By far the largest is the Pine Creek mine
MINERAL AND WATER RESOURCES OF CALIFORNIA 433
(10) which is opened in one of the world's largest, contact-metamorphic
ore deposits (Bateman, 1945 ; 1956) . This mine has been worked from
the highest outcrop at an altitude of 11,900 feet down to the Zero adit
at an altitude of 9,430 feet. An adit under construction in 1965 from
the mill level at an altitude of 7,900 feet will explore the ore zone 4,000
feet beneath the outcrop. The cumulative production is far greater
than any other tungsten mine or district in the United States; the
mine still has an outstanding potential. The ores are complex and
yield other marketable products than scheelite, including molybdenum,
copper, silver, and gold.
The quartz veins at Atolia (30) contained scheelite ore of high grade
and were formerly important producers. The known deposits are
now mostly worked out.
Scheelite has been produced profitably from four medium-sized
contact-metamorphic deposits on the west slope of the Sierra Nevada,
in Madera and Fresno Counties: Strawberry' (6), Consolidated Tung-
sten (18), Tulare County Tungsten (20), and Tungstore (24). The
only important known reserves are in the Strawberry mine. Darwin
(21) and Starbright (31) were also medium-sized profitable producers
that are now largely depleted.
Tungsten is present in solution in the brines of Searles Lake (28)
in very small concentrations, only 0.005 to 0.008 percent of WO3 (Car-
penter and Garrett, 1959). The total amount contained in the brines
is estimated at 8.5 million units of WOa. Recovery methods have been
developed but are not yet economic.
California appears assured of a leading rank in production of tung-
sten in the TTnited States for a long time. The known resources are
large and new discoveries are probable.
Tungsten deposits or districts that contain more than 10 short tons
of W are shown on the map, fig. 83, next page) and are listed in table
49, keyed to the map. Deposits numbered 1, 22, 30, 32, and 36 are
veins; 28 is brine, and the others are contact-metamorphic scheelite
deposits.
Selected References
Bateman, P. C. 1945. Pine Creek and Adamson tungsten mines, Inyo County,
California : California Jour. Mines and Geology, v. 41, p. 231-249.
, 1956, Economic geology of the Bishop tungsten district, California :
California Div. Mines Special Kept. 47, 87 p.
-, 1965. Geology and tungsten mineralization of the Bishop tungsten dis-
trict. California : V.S. Geol. Survey Prof. Paper 470.
Bateman, P. C. and Irwin, "W. P., 19.54, Tungsten in southeastern California,
[Pt.] 4 in Chap. 8 0/ .Tahns, R. H.. e<l., Geology of southern California: Cali-
fornia Div. Mines Bull. 170, p. 31-39.
Brown, C. .7.. 1961. The geology of the Flat River tvingsten deposits, Canada
Tungsten Mining Corp.. Ltd. : Canadian Mining Metall. Bull., v. 54, no. 591,
p. 510-512.
Carpenter, L. G.. and Garrett, D. E.. 1959, Tungsten in Searles Lake : Am. Inst.
Mining Metall. Petroleum Engineers. Trans., v. 214. p. 301-303.
Farmin, Rollin, 1941, Occurrence of scheelite in Idaho-Maryland mines at Grass
Valley, California : California Jour. Mines and Geology, v. 37, no. 2, p. 224.
Forhes, J. M., 1965, Tungsten : Eng. and Mining Jour., v. 1, 166, no. 2, p. 148-154
(Annual Review).
Goodwin. J. G., 1958, Mines and mineral resources of Tulare County. California :
California Jour. Mines and Geology, v. 54, no. 3, p. 317-492.
Hall, W. E., and MacKevett, E. M., Jr., 1958, Economic geology of the Darwin
quadrangle, Inyo County, California : California Div. Mines Spec. Rept. 51,
p. 59-66.
434
MINERAL AND WATER RESOURCES OF CALIFORNIA
Hazenbush, G. C, 1952, Geology of the Starbright tungsten mine, San Bernardino
County, California : California Jour. Mines and Geology, v. JS, no. 3, p. 201-206.
Holliday, R. W., and Burke, M. J., 1957-1959, Tungsten : U.S. Bur. Mines. Min-
erals Yearbook, 1956, p. 1,225-1,244; Minerals Yearbook, 1957, p. 1,203-1,218;
Minerals Yearbook, 1958, p. 1,089-1,100.
Krauskopf, K. B., 1953, Tungsten deposits of Madera, Fresno, and Tulare Coun-
ties, California : California DIa'. Mines Special Rept. 35, 83 p.
Lemmon, D. M., and Dorr. J. V. N. 2d, 1940, Tungsten deposits of the Atolia
district, San Bernardino and Kern Counties, California : U.S. Geol. Survey
Bull. 922-H, p. 205-245.
Lemmon, D. M., and Tweto. O. L., 1962, Tungsten in the United States, exclusive
of Alaska and Hawaii : U.S. Geol. Survey Mineral Inv. Resource Map MR-25,
scale 1:3,168.000.
Rinehart. C. D.. and Ross, D. C, 1956. Economic geology of the Casa Diablo
Mountain quadrangle, California : California Div. Mines Spec. Rept. 48, 17 p.
, 1964, Geology and mineral deposits of the Mount Morrison quadrangle,
Sierra Nevada, California : U.S. Geol. Survey Prof. Paper 385, 106 p.
Ti"^-
1
a
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\
T
7) o
^ OMon
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~1 O
>
I
^<
V
v/t~)u
-sy%>, ^
r'^l^^
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EXPLANAT ION
• o
More than 10.000 short tons contained W
(open circle for Searles Lake)
•
1.000-10.000 short tons contained W
(126,1 00-1 ,261 ,000 units WQ^ )
100-1,000 short tons contained W
(12.610-126.100 units WO3)
_L„ 1 0-1 00 short tons conta i ned W
(1 .261 -12,610 units WO3)
Figure 83. Tungsten in California, showing mines or districts with combined
production and reserves containing more than 10 tons W (numbers refer to
table 49) .
MINERAL AND WATER RESOURCES OF CALIFORNIA
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.3 u
o'5
r.* CO "
.2 '5''
a.2"
So
a
l«g.2
! 3 3^^
■SJoJg
3S t. o
a.'§c:.2.3
Es 03-0 2
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aj-O"^ 2 «»
a) 03 -a 3 k^
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IM ffO Tt« 10 CO t^ 00 03 O
^ ^ ,-(,-( 1-1 .-I .-. ,-( c^
•"HNco-^^ctor^oooiOf-f
436 MINERAL AND WATER RESOURCES OF CALIFORNIA
Stevens, R. ¥.. Jr.. 1964, Tungsten: U.S. Bur. Mines, Minerals Yearbook. 1963.
p. 1.155-1,168.
Stewart, R. M., 1957, Tungsten, in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176. p. 655-667.
Troxel, B. W.. and Morton. P. K., 1962, Mines and mineral i-esources of Kern
Count.v. California : California Div. Mines and Geology County Rept. 1. 370 p.
Wright. L. A.. Stewart. R. M.. Gay. T. E.. .Jr.. and Hazenbush, G. C. 19.53, Mines
and mineral deposits of San Bernardino County. California : California Jour.
Mines and Geology, v. 49, no. 1, p. 49-192.
URANIUM
(By G. W. Walker, U.S. Geological Survey, Menlo Park, Calif., and A. P. Butler,
Jr., U.S. Geological Survey, Denver, Colo.)
Uranium is a metallic element which consists of three semistable
isotopes, U-^®, U-^^, and IJ-^*. Heat released when a uranium atom
fissions (splits) makes uranium an important source of energy for
weapons and for generating power, its principal uses. The U"'^
isotope, constituting 0.7 percent of natural uranium, fissions readily
whereas the abundant U"^ isotope, constituting over 99 percent of
natural uranium, must first l^e converted in a nuclear reactor to the
readily fissionable plutonium isotope, Pu-^^.
The principal nonenergy uses of uranium are in the ceramics and
chemical industries.
Most of the uraniimi mined in the United States comes from strati-
form deposits in continental standstones and conglomerates, princi-
pally in Xew Mexico, Utah, Colorado, and "Wyoming. Less important
deposits of uranium are found in lacustrine limestone and coal or
carbonaceous sediments interbedded with continental sedimentary
rocks. Vein and related fracture-controlled deposits are present in
nearly all kinds of rocks widely distributed in the United States.
Until about 1950 veins were the dominant world source of uranium
( or radium) , but they now represent only a subordinate source. Large,
low-grade concentrations of uranium are present in marine black
shales, phosphorites, and locally in some granitic rocks. L^ranium
minerals also have been reported from many pegmatites, but, in gen-
eral, are not sufficiently abimdant to be mined economically.
Although uranium minerals have been known in California at least
since 1895 (Rickard, 1895, p. 239), the first uranium ore marketed
from the State was shipped from the Tlium Bum Claim near Big Bear
Lake, San Bernardino County, in the early summer of 1954. Also in
1954, a railroad carload (about 48 tons) of uranium ore averaging
0.62 percent U.-iOs was shipped from the Miracle mine in Kern River
Canyon, Kern County. Since then about 9,000 tons of ore has been
shipped from 17 different properties in the State,^ and the uranium
contained in this ore places California twelfth in rank among uranium-
producing states. Only two deposits are recorded as having produced
in 1964.
Uranium ores have been mined in California from several different
kinds of deposits in widely separated parts of the State (Walker,
Lovering, and Stephens, 1956 : Troxel, Stinson, and Chesterman, 1957) .
1 As compiled from information furnished by the Grand Junction Office, U.S. Atomic
Energy Commission.
MINERAL AND WATER RESOURCES OF CALIFORNIA
437
Nearly all the deposits are in the Sierra Nevada, Great Basin, and
Mojave Desert psysiographic provinces (fig. 84) or parts of adjacent
provinces.
Some of tlie deposits, for example, those at the Miracle and Kergon
mines in the southern Sierra Nevada area fig. 84, (No. 7) and at the
Northeast claim group in the southern McCoy Mountains area (No.
11), are readily identified as veins in which primaiy or secondary
uranium minerals, or both, occur in faults and fracture zones. Dis-
seminated primary uranium minerals along a contact between granite
and schist is the ore at the Thum Bum claim in the San Bernardino
Mountains area (No. 10) ; small vein deposits of uranium in limestone
41"
Eur.'lca,
40 °J
124°
119°
EXPLANAT ION
1. Hallelujah Junction area
2. Peavine area
3. J un i pe r nine
4. Mamieoth Lakes area
5. Ch iq ul t o-Jackass Creeks area
6. Olancha area
7. Southern Sierra Nevada
8. Taf t-McKi 1 1 r ick area
9 . Nob Hill pr ospect area
10. San Bernardino Mountains area
11. Southern McCoy Mountains
12. Eastern Saltan Trouih area
\
\\
J^^.
.yOLo\-i.-VEL DORADO,' V..
-^- "sANTA 'fV f'y
,SJ^. tlara!, V C V^ ^"S"
37° — VSHZ >C\ ,, ; \. /\ N. ^
+
39- •> 1 ,000 0< 1 .000
Tons of ore mined through 1964
V \ SsOLANo;,-5 ^\_k" O
"x_ Prospect or mineral occurrence
^■v 118°
TUOLUMNE QvmoNO^ -[-38°
4 ^ -^
^■^.^-;
S*r,^i:>-^ —
S
V,
\MONTEREY
36°+
122°
SAlf-/\ .
'j. \\. ^-FRESNff
v^ENITO] \ "7 /\
^v^
SAN i'
^LU.j; ^^
'Z' OBISPO
- ^SANTA- ul"^ * \y\^ _r*.i»*i
vSX ^K AT "
.^BARBARAl -4> \]E.OS
— X
Bishop "v
^ ^\ * I n\ o ^ \.
y Aft * ^/x '--i^^
Bak«rBfield
a"
o
7
/kern
3.°+
oJ*
»MOJ A
n/e
X
SAN BERNARDINO
r
S I^» E % I
y
iimperiaC-~--s .'
SALTONM -=H;33°
Figure 84. Uranium in California.
438 MINERAL AND WATER RESOURCES OF CALIFORNIA
and schist, and one nnusual allanite- and monazite-bearin^ vein in
biotite gneiss are also present in the area. Secondary uranunn min-
erals are locally abundant in quartz veins and shear zonevS cutting de-
composed granitic rocks in Plumas County near the Hallelujah Junc-
tion area (Xo. 1) ; hoAvever, no ore has been shipped from these de-
posits. Deposits in the Mammoth Lakes area (No. 4) contain second-
ary uranium minerals, mostly as networks of tiny veinlets, and minor
pitchblende in poorly sorted material thought to be either glacial till
or the renmants of a talus apron (Einehart and Ross, 1964, p. 100).
Another group of productive deposits, which are not so readily cate-
gorized, consists of fracture and bedding plane coatings or impregna-
tions of brightly colored secondary uranium in rocks of Tertiary age.
Some are in or near faults and commonly have been classed as veins ;
others are mainly stratiform. The host rocks include: (a) clayey and
tulTaceous continental sedimentary rocks interbedded with volcanic
rocks in northeastern Tuolumne County (No. 3), which is the largest
single source of uranium ore mined in California to date (1965) ; (b)
continental arkosic sandstone and bentonitic tuft' that lie on an irre-
gular surface on Jurassic granitic rocks in the Olancha area (No. 6) ;
(c) volcanic and continental sedimentary rocks in the Hallehljah
Junction area (No. 1) ; (d) fractured volcanic rocks in the Pea vine
area (No. 2) ; and (e) marine sedimentary rocks in the Taft-McKit-
trick area (No. 8). A large number of geologically similar deposits,
with no recorded production, are present in the western part, of the
Mojave Desert province.
Small amounts of carnotite and possibly other secondary uranium
minerals occur with pods or lenses of carbonaceous material in Ter-
tiaiy sandstone beds in several places in western Ventura County, prin-
cipally near Ojai (Troxel, Stinson, and Chesterman, 1957) .
Sand and gravel of possible Pleistocene age containing some partly
decomposed plant material are locally mineralized with uranium in
the Chiquito- Jackass Creeks area in Madera County (No. 5). Some
of this material has been mined.
Several peat bog deposits in the southern Sierra Nevada area com-
posed of woody fragments, black carbonaceous matter, silt, and
arkosic sands, contain an appreciable amount of uranium in some
unidentified form, possibly absorbed in the peat. One deposit aver-
ages about 0.10 percent and another about 0.24 percent UsOs- No ore
has been shipped from these deposits to date (1965).
Extensive marine phosphorites of Miocene age that are commonly
radioactive are present in a number of places in the southern Coast
Ranges and along the west side of the San Joaquin Valley (H. D.
Gower, oral communication, 1965). The source of the anomalous
radioactivity is not known but by anology with phosphorites elsewhere
(Butler and Schnabel, 1956, p. 87-38) it can be assumed that it comes
mostly from uranium. Ultimately, the uranium may be extracted as
a by-product of phosphate mining.
Uranium also has been reported in some asphalt -bearing rocks in
California ( Hail, Myers, and Horr, 1956), but is insufficiently con-
centrated to be economically extracted.
Compared to the large economic deposits in other parts of the
United States most of the uranium deposits of California are small,
and none are thought to contain large reserves of minable uranium ore.
MINERAL AND WATER RESOURCES OF CALIFORNIA 439
However, future prospecting undoubtedly will uncover many new
occurrences of uranium minerals comparable to those in granitic rocks
in Kern River Canyon, in metamorphic rocks in tlie McCoy Moun-
tains, and in continental sedminetary rocks in Tuolumne County.
Some may be rich enough to support mining on a small scale but are
unlikely to contribute appreciably to total resources in the United
States.
Selexjted References
Butler, A. P., Jr., and Schnabel, R. W., 1956 Distribution and general features of
uranium occurrences in the rnite<l States, in Page, L. R., and others. Contribu-
tions to the geology of uranium and thorivani by the United States Geological
Survey and Atomic Energy Commission for the United Nations International
Conference on Peaceful Uses of Atomic Energy, Geneva, Switzerland, 1955 :
U.S. Geol. Survey Prof. Paper .300, p. 27-40.
Hail, W. J., .Jr., Myers. A. T.. and Horr. C. A., 1950, Uranium in asphalt-bearing
rocks of the western T'nited States, in Page, L. R., and others. Contributions
to the geology of uranium and thorium by the United States Geological Survey
and Atomic Energy Commission for the United Nations International Confer-
ence on Peaceful Uses of Atomic Energy, Geneva, Switzerland, 1955 : U.S. Geol.
Survey Prof. Paper 300, p. 521-526.
Rickard, T. A., 1895, Certain dissimilar occurrences of gold-bearing quartz :
Colorado Sci. Soc. Proc. 4, p. 323-339.
Rinehard, CD., and Ross. D. C. 1964, Geology and mineral deiwsits of the
Mount Morrison quadrangle, Sierra Nevada, California, with a section of a
gravity study of I^ong Valley, by L. C. Pakiser: U.S. Geol. Sun-ey Prof. Paper
385, 106 p.
Troxel, B. W.. Stinson, M. C. and Chesterman, C. W., 1957, Uranium : California
Div. Mines Bull. 176, p. 669-087.
Walker, G. W., Lovering, T. G., and Stephens, H. G., 1956, Radioactive deposits
in California : California Div. Mines Si>ec. Rept. 49, 38 p.
VANADIUM
(By R. P. Fischer, U.S. Geological Survey, Denver, Colo.)
The consumption of vandium in the United States increased from
about 1,900 tons in 1955 to about 3,500 tons in 1964, according to
figures published by the U.S. Bureau of Mines. Of the total vanadium
consumed, 75 to 80 percent has gone into special engineering, struc-
tural, and tool steels, where it is used as an alloy to control grain size,
impart toughness, and inhibit fatigue. The other principal domestic
uses have been in nonferrous alloys and chemicals (Busch, 1961).
Four geologic types of deposits have yielded most of the world's
supply of vanadium. The bulk of domestic vanadium, and nearly
half of the world supply, has come from deposits of vanadium- and
uranium-bearing sandstone in southwestern Colorado and the adjoin-
ing parts of Utah, Arizona, and New Mexico. The other principal
sources have been a deposit of vanadium-bearing asphaltite in Peru,
vanadate minerals from the oxidized zones of some base-metal deposits
in Africa, and vanadium-bearing iron deposits in Europe and Africa.
These iron deposits and similar ones in many parts of the world con-
tain very large resources of vanadium ; probably they will become in-
creasingly important as sources of vanadium in the future.
Of these four principal types of productive vanadium deposits, only
two are known in California — vanadate deposits with base metals, and
vanadium-bearing iron deposits. Accumulations of vanadium above
trace amounts are known in only two other geologic types of occur-
440
MINERAL AND WATER RESOURCES OF CALIFORNIA
rences in the State. These deposits and occurrences are sliown on
figure 85, and tliey are briefly described below. Xone of tliese are
judged to be of significant commercial potential.
Minerals composed of the vanadates of lead, zinc, or copper have
been found in the oxidized zones of several deposits in southern Cali-
fornia, but only two have any recorded production. Hewett (1956,
p. 134) states that about 40 tons of concentrates containing vanadates
were recovered at the Leiser Ray mine (No. 1, fig. 85), San Bernar-
dino County, in 1916-1917, and Brown (1923, p. 63) reports the re-
covery of some vanadium-bearing concentrates from the Eldorado
mine (No. 2), Riverside County, in 1918. Similar occurrences are
common in the oxidized zones of base-metal deposits in southwestern
United Statese and in many other parts of the world where the climate
is arid or semiarid. In most of these deposits the Aanadate minerals
occur only as scattered crystals or sparse powdery coatings, but in a
few" deposits these minerals are abundant enough in patches or bodies
EXPLANATION
•
Vanadate de p os i t
( pr oduc t i ve ;
▲
Va nada t e occur r e nee
▲
Va nad i um-bea r i ng
t i tan i f e r ous ma g.ne t i t e
O
Va na d i um-bea ring
uranium de pos J t
■
j te with
Numbe r s refer
to text
37*
TBOUGHjir:^
Figure 85. Vanadiiun in California.
MINERAL AND WATER RESOURCES OF CALIFORNIA 441
to yield ore by selective mining or mill concentrating. None of the
deposits in California are known to have large bodies of rock contain-
ing vanadate minerals.
The ultramafic rocks of the San Gabriel Mountains (No. 3, fig. 85),
Los Angeles County, contain vanadium-bearing titaniferous magne-
tite in small high-grade pods and larger low-grade disseminations,
and along some of the stream valleys nearby are placer deposits of
vanadium-bearing ilmenite and magnetite sand. Although a few
samples from these deposits assay 0.5 percent or more V-O:, most
samples contain much less vanadium (Benson and others, 1962; Oake-
shott, 1948). Probably the vanadium content of these deposits is too
low to encourage attempts to recover this metal, even if the deposits
are worked for titanium and iron. Many similar titaniferous mag-
netite deposits in other parts of the world are larger and higher
grade, and some contain 0.5 percent V^O^ or more.
Vanadium-bearing minerals occur in the uranium deposit at the
Miracle mine (No. 4, fig. 85), Kern County (Bowes, 1957), but the
average vanadium content of many samples from the deposit is only
about 0.14 percent V=0:i, which is too low to attempt vanadium recov-
ery. Vanadium minerals are absent or inconspicuous in other ura-
nium deposits in California. Many of the known uranium deposits
in California are of the vein type, and probably of hydrothermal
origin, and vanadium is not commonly abundant in deposits of this
type.
Roscoelite, the vanadium-bearing mica, is a minor gangue mineral
in some of the gold-quartz veins in El Dorado County (No. 5, fig. 85)
(Murdock and Webb, 1956, p. 287). No assay data showing the
vanadium content of the ore as mined have been found, but the con-
tent is assumed to be too low to consider vanadium recovery. Small
amounts of roscoelite are common in gold-bearing veins, especially
those containing gold-telluride minerals, in other parts of the world.
Selected References
Benson, W. T., Engel, A. L., and Heinen, H. J., 1962, Titaniferous magnetite
deposits in Los Angeles County, California : U.S. Bur. Mines Rept. Inv. 5962,
40 p.
Bowes, "W. A., 1957, Preliminary report on uranium occurrences in Kern River
Canyon, Kern County, California : U.S. Atomic Energy Comm., RME 2,059,
pt. 1, 34 p.
Brown, J. S., 1923, The Salton Sea region, California : U.S. Geol. Survey Water-
Supply Paper 497.
Busch, P. M., 1961, Vanadium, a materials survey: U.S. Bur. Mines Inf. Circ.
8060.
Hewett. D. F., 1956, Geology and mineral resources of the Ivanpah quadrangle,
California and Nevada : U.S. Geol. Survey Prof. Paper 275, 172 p.
Murdock, Joseph, and Webb, R. W., 1956, Minerals of California : California
Div. Mines Bull. 173, 8th ed., 452 p.
Oakeshott, G. B., 1948, Titaniferous iron-ore deposits of the western San Ga-
briel Mountains, Los Angeles County, California : California Div. Mines Bull.
129, pt. P, p. 245-266.
WOLLASTONITE
(By B. W. Troxel, California Division of Mines and Geology, Los Angeles, Calif.)
California is endowed with large deposits of wollastonite and wol-
lastonite-bearing rocks which, to date, have been utilized mostly as
sources of ornamental building stone (field stone). Wollastonite has
67-164 O— 6fr— pt. 1—29 ^
442 MINERAL AND WATER RESOURCES OF CALIFORNIA
been produced from two sources in California ; from deposits near
Willsboro and Lewis, New York; from a deposit at Lappeenranta,
Finland; and from a deposit near the Klior Dirbat well in the Red
Sea Hills, Sudan.
Beneficiated wollastonite has proved satisfactory for use in floor
and wall tile bodies, in porcelain fixtures, thermal insulation products,
acoustical tile, frits for enamelware, glazes and dinnerware, electrical
insulator products, as a paint extender, filler in asphalt-based floor
tiles, in welding rod coatings, and mineral wool. It has certain appli-
cations as coating and filler for paper, as an abrasive, a bond for
abrasive wheels, as filler for plastics and cement, and as a filter.
Bonded and baked wollastonite products could be used for wall board
and exterior sheathing (Amberg and McMahon, 1949).
Wollastonite (CaO-SiOo) ordinarily occurs as a contact-meta-
morphic mineral in siliceous limestone masses that have been meta-
morphosed near intrusive igneous bodies. Wollastonite commonly is
associated Avith diopside, idocrase, garnet, epidote, calcite, and quartz.
Locally, the rocks may be infused with metallic sulphides. In Califor-
nia, contact-metamorphic environments are most common on the
borders of granitic rock masses in the Sierra Nevada, Great Basin,
Mojave Desert, and Peninsular Ranges.
The first production of wollastonite in California, and possibly in
the world, was in 1933 from a deposit near Code Siding, north of
Randsburg, Kern County. Since 1955, wollastonite has been obtained
from sources in the Blythe area, but most of these have yielded undis-
closed quantities of field stone for use as ornamental building stone.
A deposit near Blythe was explored about 1958 as a source of wol-
lastonite for use as the principal raw material in mineral wool at a
plant near Blythe, Riverside County; no significant quantity of min-
eral wool was produced or marketed. Since early 1964, several Cali-
fornia deposits of wollastonite have been evaluated by ceramic pro-
ducers but by mid-1965 none had been developed.
The United States ranks first in production of wollastonite. New
York is the principal source in the United States, and California
ranks second. Data on quantity and value of California production
are undisclosed, but wollastonite production probably averages a few
thousand tons each year, valued at less than $15 per ton, f .o.b. mine.
OCCURRENCKS IN CALIFORNIA
In the Big Maria Mountains, 16 miles northwest of Blythe, eastern
Riverside County, pods of high-purity wollastonite occur in crystalline
limstone (fig. 86). The pods range from a few inches in maximum
dimension to as much as 1,800 feet in length. Mixed metasedimentary
rocks associated with the limestone also contain wollastonite-bearing
layers. These rocks appear to be as much as 500 feet thick and can be
traced laterally for about 4 miles. The wollastonite-bearing rock is
fine grained and is interbedded Avith fine-grained diopside and thin
layers of limestone. Local beds are brownish-gray and appear to
have a relatively high iron content. Other beds are nearly pure white.
Similar wollastonite-bearing rocks occur in the Little Maria Moun-
tains, the Arica Mountains, and probably elsewhere north of Blythe.
MINERAL AND WATER RESOURCES OF CALIFORNIA
443
(§)
EX
PLANA T I ON 5^°~r
Oe pas Its tha t have y ie Ided
c omme rcial mollastonite
Deposits that contain at leas
100,000 tons of mollastonite
Deposits of doubtful but
possible coinme r c I a I signlfica
117'
Figure 86. Wollastonite in California.
White, coarsely crystalline wollastonite occurs in Permian limestone
in Warm Spring Canyon on the east slope of the Panamint Range,
Inyo County. The largest body is an elongate lens about 750 feet long
and 35 feet in average thickness. Most of the rock in the lens consists
almost wholly of wollastonite, but siliceous and calcareous material
forms local layers and irregular masses. Diopside, quartz, and calcite
are minor constituents tliroughout the lens of wollastonite. Wolla-
stonite occurs in re&rystallized limestone at Striped Butte, several
miles farther west up Warm Spring Canyon and probably elsewhere
locally in the Permian strata.
Wollastonite-bearing metasedimentary rocks also occur in the north-
eastern part of the El Paso Mountains near Code Siding, north of
Randsburg in Kern County. In these rocks the wollastonite occurs as
intricately folded layers interstratified with nearly equal or greater
amounts of diopside and garnet. The sequence is several tens of feet
in total thickness. In 1933-1934, this deposit yielded an undisclosed
amount of material for the manufacture of mineral wool.
Since 1957, wollastonite, of undetermined quantity and quality, has
been modestly explored in a few masses of recrystallized limestone
along the north edge of Hunter Mountain, Inyo County. Those de-
posits may contain large reserves of wollastonite or wollastonite-bear-
ing rock. Metamorphosed limestone masses in Sheep Creek, Avawatz
Mountains, San Bernardino County, may contain significant quantities
of wollastonite but are as yet unexplored.
Several wollastonite occurrences also have been reported in crystal-
line limestone in the Mojave Desert, principally near Barstow and Vic-
torville. Still other wollastonite deposits exist throughout the Sierra
Nevada where tlie mineral has been foiuid in metamorphosed limestone,
especially in the vicinity of tungsten deposits. Wollastonite also oc-
curs in metasedimentary rocks near Darwin, Inyo County, and has
444 MINERAL AND WATER RESOURCES OF CALIFORNIA
been noted in the north part of the Argus Range ahnost due east of
Darwin.
Of the 37 occurrences of wollastonite in California, reported in Bul-
letin 173 of the California Division of Mines (Murdoch and Webb,
1956) , only those described above appear to be capable of yielding com-
mercial quantities of the relatively pure mineral, but not all of the oc-
currences have been investigated.
Selected References
Amberg, C. R., McMahou, J. F., and others, 1949, Wollastonite, an industrial
mineral : New York State College Ceramics Bull. 4, 60 p.
Buruham, K. D., and Wainer, Eugene, 1964, Potential uses of wet processed
wollastonite : SME of Am. Inst. Min. Engrs., Preprint No. 64H331, 14 p.
Carpenter, F. Scott, Jr., 1964, Wollastonite — its uses and its potential : SME of
Am. Inst. Alin. Engrs., Preprint No. 64H32S, 15 p.
Choate, L. W., 1964, Evolution of wollastonite as an industrial mineral : SME of
Am. Inst. Min. Engrs., Preprint No. 64H304, 4 p.
Murdock, Joseph, and Webb, R. W., 1956, Minerals of California : California Div.
Mines Bull. 173, p. 346-348.
Neely, J. R. and Knapp, W. J., 1964, California woUastonites : Ceramic News,
May, p. 12-13.
Troxel, B. AV., 1957. Wollastonite, in Mineral commodities of California : Cali-
fornia Div. Mines Bull. 176, p. 693-697.
Troxel, B. W. and Morton, P. K.. 1962, Mines and mineral resources of Kern
County, California : California Div. Mines and Geology County Rept. 1, p. 344.
U.S. Bureau of Mines Minerals Yearbooks, 1946-1963.
ZINC
(By P. K. Morton, California Division of Mines and Geology, Los Angeles, Calif.)
Zinc has been utilized by man since the dawn of civilization. Metal
artifacts dating back 2,000 years contain zinc, but it is thought that
these early uses were largely the accidental result of crude smelting
of complex copper-tin-zihc ores. Separate identity of zinc is not
known before the 16th century, and recoveiy for commercial use did
not occur until the 18th century. Utilization increased steadily there-
after, and, in 1963, only steel, copper, and aluminum outranked zinc
in total production. Total world production in 1963 was 3,970,000
short tons of which the United States produced 529,250 tons or more
than 13 percent. The primary sources of lead-zinc-copper deposits
in the United States, in the order of total production, are Oklahoma,
New Jersey, Missouri, Kansas, Montana, and Idaho. The leading-
states in 1963 were Tennessee, Idaho, New York, Colorado, and Utah.
The pricipal domestic uses of slab zinc in 1963 were zinc base alloys
(die castings, alloy dies and rods, slush and sand castings) , -12 percent;
galvanizing, 38 percent ; brass products, 12 percent ; the remainder was
used mainly for rolled zinc, zinc oxide, and other zinc compounds.
Mineable zinc occurs principally in the form of the sulfide, sphal-
erite, deposited as open-space filling and replacement bodies of hydro-
thermal origin in association with lead, copper, gold, and silver.
These deposits commonly occur as com23lex ore masses in the form
of veins, flat or gently inclined tabular bodies, or as lenticular to
irregularly shaped bodies. Most of these deposits are believed to have
originated through processes accompanying the late stages of intru-
sion of large igneous masses into the earth's crust.
MINERAL AND WATER RESOURCES OF CALIFORNIA 445
AVhere zinc-bearing ore deposits lie near the surface, sphalerite
oxidizes readily to form smithsonite (zinc carbonate), hemimorphite
(hydrous zinc silicate), and other less common oxidation proclucts.
Smithsonite and hemimorphite are important ore minerals of zinc, but
are much less abundant than sphalerite.
Although zinc-bearing ores have been mined in California since
the 1860-8, no zinc was recovered commercially until 1906, because
it "was not economically feasible. Total output for the State is about
308 million pounds. California's lead-zinc-copper industries have been
crippled in recent years by a combination of factors including, poor
reserves, increased mining and transportation costs, and depressed
prices. Production during the 5-year period 1959-1963 was only
1,270 tons valued at $305,000, which amounted to less than one per-
cent of the United States production during that period.
Occurrences in California
In California, the chief zinc-producing areas in order of total pro-
duction are the Shasta district (42 percent), the Great Basin province
(28 percent), and the Foothill Belt (15 percent). Other less produc-
tive areas noted on figure 87.
The Shasta z'/nc-ropper district lies in Shasta County at the south-
east corner of the Klamath Mountains province (fig. 87) . It is divided
into the East and West Shasta districts on the basis of lithologic and
structural differences.
Ore bodies in the East Shasta district occur as massive sulfide re-
placement lenses whicli are localized along shear zones in Triassic
Bully Hill Rhyolite and along fault contacts between Bully Hill
Rhyolite and the Pit Formation (Middle and Upper Triassic). Ore
bodies, which are as large as 400 feet in their largest dimension, com-
monly are closely grouped along shear zones (Albers and Robertson,
1961, p. 98).
Deposits of the West Shasta district also consist of massive sulfide
replacement masses of lenticular shape, but they occur as flat-lying or
gently inclined bodies in Devonian Balaklala Rhyolite. Ore controls
as recognized by Kinkel, Hall, and Albers (1956, p. 137) are (1)
stratigraphic control within Balaklala Rhyolite; (2) structural con-
trol by folds and foliation ; and (3) by location of feeder fissures for ore
solutions.
Mineralogy in the two districts is similar and it is probable that the
source of mineralizing solutions for both districts was a subjacent
igneous mass or masses of albite granite or quartz diorite.
Outlook for future exploration for hidden ore bodies in the Shasta
district appears to be favorable in light of the studies by Kinkel, Hall,
and Albers (1956) and Albers and Robertson (1961). 'More detailed
geologic studies of favorable areas supported by integrated geophysical
and geochemical techniques should yield profitable results. Of especial
value in exploring for this type of deposits are electrical, magnetic,
and gravity methods.
The Great Basin province occupies much of Nevada, Utah, and Wyo-
ming and its southwestern corner extends across most of Inyo and
Mono Counties, California. Approximately 28 percent of California
zinc production as well as 94 percent of its lead, has come from this
446
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANAT ION
BUTTE COUNTY
Big Bend Zn-Cu
CALAVERAS COUNTY
Quail Hill Zn-Cu
Penn Zn-Cu
INYO COUNTY
Cerro Gordo Pb-Zn
Copper Queen Pb-Cu-
Darwi n Pb-Zn
Estelle- Morning Star
Mon t e zuma Pb-Zn
Ml nn i el t a Pb-Zn
Modoc Pb-Zn
Ophir Pb-Zn
Santa Rosa Pb-Zn
Sh osh one Pb -Zn
Zinc H il 1 Zn- Pb
Pb-Zn
COUNTY
Pb
LOS ANGELES
Black Jack Zn
MARIPOSA COUNTY
Blue Moon Zn-Cu
NEVADA COUNTY
Spanish Pb-Cu-Zn
19.
20.
21
22,
23.
24.
25.
ORANGE COUNTY
Blue Light Zn-Pb
SAN BERNAD INO COUNTY ,
Carbonate King Zn-Cu
Mohawk Pb-Zn
SHASTA COUNTY
Afterthought Zn-Cu-Pb
Bui ly Hi 1 1 Cu-Zn-Pb
Iron Mountain Cu-Zn
Mammoth Cu-Zn
Rising Star Zn -Cu
Figure 87. Principal zinc mines in California and types of ore.
province. The deposits are widespread within the province, but the
great majority lie in a northwest-trending belt, several hundred square
miles in extent, in the southern Inyo Mountains and the Argus Range.
The geologic environments of lead-zinc deposits in the Great Basin
province are diverse, but in general the deposits occur as replacement
bodies along faults, as irregular replacement bodies in carbonate rocks,
MINERAL AND WATER RESOURCES OF CALIFORNIA 447
or as contact metasomatic deposits along the peripheral margins of
plutonic rocks. The primary ores are composed typically of galena,
sphalerite, and chalcopyrite, with minor tetrahedrite-tennantite and
gold. Gangue minerals include pyrite, pyrrhotite, altered wall rock,
quartz, calcite, jasper, fliiorite, and barite. The controlling factors
in this region appear to have been: (1) proximity to Cretaceous plu-
tonic rocks of silicic to intermediate composition, (2) stratigraphic
control in certain carbonate formations, and (3) faults to provide ade-
quate channels for transport of mineralizing solutions and convenient
loci for deposition.
Because of the widespread distribution of deposits in this province,
exploration for new deposits constitutes a major problem; on the
other hand it presents a better potentiality in that it offers more areas
for investigation. Reconnaissance geochemical sampling may offer
some solution to narrowing down the number of areas for future ex-
ploration. District studies employing coordinated geological, geo-
chemical, and geophysical techniques are needed, and should, if under-
taken, result in discovery of new deposits.
The Foothill Belt constitutes a narrow northwest-trending belt
along the southwestern front of the Sierra Nevada from Fresno County
northwestward to Butte County, a distance of about 250 miles. This
belt lies along the western edge of Sierra Nevada geologic province.
The copper-zinc deposits within the Foothill Belt consist of lenticu-
lar sulfide replacement bodies lying along steeply dipping shear zones
in Paleozoic and Jurassic metavolcanic and metasedimentary rocks.
They are associated with zones of sericitization, silicification, pyritiz-
ation, or chloritization developed by hydrothermal acton. The de-
posits have been divided into four groups by Heyl (1944, p. 11-29).
Two are exclusively copper deposits ; the remaining two are character-
ized by a composition of sphalerite, chalcopyrite, pyrite, pyrrhotite,
milky quartz, calcite, and small amounts of gold and silver.
According to Heyl, ore deposition was largely controlled by struc-
tural features including (1) intersections of bifurcations of faults and
shear zones, (2) changes of strike and dip of faults, (3) irregularities
on contacts between rocks of markedly different competency, and (4)
intersection of faults with such contacts.
The deposits of the Foothill Belt have contributed about 15 percent
of the total State output, and will doubtless contribute more in the
years to come. The mode of occurrence of the deposits is fairly well
established but, as is also true of the deposits of the other two provinces,
little is know^n of their origin, and further study is necessary. The
orderly drainage pattern of the Foothill Belt and its uniform linear
nature lends itself well to systematic geochemical reconnaissance.
Anomalous areas can be studied by more detailed and coordinated
geological, geochemical, and geophysical methods.
The potentialities of the three zinc provinces and many other smaller
districts are great. The zinc-lead-copper resources of California have
been largely neglected in recent years. Exploration and economic
studies have not kept pace with the rate of development of new tech-
niques in the earth sciences. With application of these techniques by
both industry and go\ernment, California can become an important
source.
448 MINERAL AND WATER RESOURCES OF CALIFORNIA
Selected References
Albers, J. P., and Robertson, J. F., 1961, Geology of the East Shasta copper-zinc
district, Shasta County, California : U.S. Geol. Survey Prof. Paper 338, 107 p.
Bishop, O. M., 1960, Zinc, in Mineral facts and problems : U.S. Bur. Mines, Bull.
515, p. 975-994.
Clark, L. D., 1964, Stratigraphy and structure of part of the western Sierra
Nevada nietamorphic belt, California : U.S. Geol. Survey Prof. Paper 410, 70 p.
Eric, J. H., 1948, Tabulation of copper deposits of California, in Copper in Cali-
fornia : California Div. Mines. Bull. 144.
Goodwin, J. G., 1957, Lead and zinc in California : California Div. Mines Jour.,
v. 53, nos. 3, 4, p. 353-724.
Hall, W. E., and MacKevett, E. M., 1958, Economic geology of the Darwin
quadrangle : California Div. Min. Spec. Rept. 51, 73 p.
—■ , 1963, Geology and ore deposits of the Darwin quadrangle, California :
U.S. Geol. Survey Prof. Paper 368, 87 p.
Hall, W. E., and Stevens, H. G., 1963, Economic geology of the Panamint Butte
quadrangle and Modoc district, Inyo County, California : California Div. Mines
and Geology, Spec. Rept. 73, 39 p.
Heyl, G. R., 1948, Foothill copper-zinc belt of the Sierra Nevada, in Copper in
California : California Div. Mines Bull. 144, p. 11-29.
Johnstone, S. J., and Johnstone. Margery G., 1961, Minerals for the chemical and
allied industries : New York, John Wiley and Sons, Inc., p. 705-732.
Kinkel, A. R., Jr., Hall, W. E., and Albers, J. P.. 1956. Geology and base-metal
deposits of West Shasta copper-zinc district, Shasta County, California : U.S.
Geol. Survey Prof. Paper 285, 156 p.
McKnight, E. T., Newman, W. L., and Heyl, A. V., Jr., 1962, Zinc in the United
States : U.S. Geol. Survey Mineral Inv. Resource Map MR-19.
Norman, L. A., and Stewart, R. M., 1951, Mines and mineral resources of Inyo
County : California Div. Mines Jour., v. 47, no. 1, p. 17-223.
O'Brien, J. C, 1957, Zinc, in Mineral Commodites of California : California Div.
Mines Bull. 176, p. 69^^706.
Rankama, Kalervo, and Sahama, Th. G., 1960, Geochemistry : Univ. of Chicago
Press, p. 708-714.
Schroeder, H. J., 1963, Zinc, in Minerals Yearbook : U.S. Bur. Mines, p. 1221-1258.
, 1965, Zinc, in Mineral facts and problems : U.S. Bur. Mines Bull. 630, 22 p.
U.S. Bureau of Mines, 1951, Zinc materials survey : 429 p.
U.S. Bureau of Mines. 1965, Zinc, //; Commodity data summaries, p. 164—165.
Wright, L. A., Stewart, R. M., Gay, T. E., and Hazenbush, G. C, 1953, Mines and
mineral resources of San Bernardino County, California : California Div.
Mines Jour., v. 49, nos. 1, 2, p. 49-192.
ZIRCONIUM AND HAFNIUM
(By M. C. Stinson, California Division of Mines and Geology, San Francisco,
Calif.)
Zirconia (zirconium oxide) and zirconium compounds are made
directly from the commercial source minerals, zircon and baddeleyite.
Zircon is used in refractories and foundry sands. Stabilized zir-
conium oxide is used to insulate high-frequency induction furnaces
and to line jet enofines. Zirconium metal is used in nuclear reactors,
in steel alloys, and in surgery. Hafnium is used in nuclear reactors.
Zirconium is more abundant in the earth's crust than nickel, copper,
zinc, lead, tin, and mercury combined. The earth's crust contains ap-
proximately 0.03 percent zirconium and 0.004 percent hafnium.
Hafnium occurs in nature only with zirconium-bearing minerals and
has almost the same chemical properties as zirconium. Of the zir-
conium minerals, only zircon and baddeleyite are abundant enough to
be of commercial interest. These ores always contain from % to 2
percent hafnium.
MINERAL AND WATER RESOURCES OF CALIFORNIA 449
Zircon (zirconium silicate), the most widely distributed and
abundant zirconium mineral, is a common constituent of many igneous
and metamorphic rocks as well as sands resulting- from the disinte-
gration of these rocks. Many sedimentary rocks contain zircon be-
cause the mineral is hard and chemically resistant to weathering. In
ultraviolet light, most specimens of zircon fluoresce a brilliant orange,
red, or yellow,
Baddeleyite (zirconium dioxide), much less widely distributed than
zircon, occurs in igneous rocks that are deficient in silica, and in sedi-
mentary rocks derived from them.
The zirconium-hafnium content of igneous and metamorphic rocks
rarely exceeds 0.06 percent. These elements are not known to be con-
centrated in veins, but the high-specific gravity of zirconium minerals
leads to their concentration in placer deposits. As the expense of re-
moving zirconium- and hafnium-bearing minerals from hard rocks is
much greater than from placer deposits, and as placer deposits com-
monly are richer in such minerals, the commercial production of zir-
conium and hafnium has been limited to sands. Furthermore, other
minerals of commercial value are often found associated wdth placer
deposits of zirconium- and hafnium-bearing minerals and are re-
covered simultaneously and at little extra expense.
The bluish- violet mineral hyacinth (also called jacinth or jargon)
has been known for numy years as a semiprecious gem stone. In-
taglios of zircon are common among ancient gems. In the 18th
century, colorless zircons were supposed to be inferior or imperfect
diamonds and were known as "Matera diamonds" because many were
found in the Matera district of Ceylon. M. H. Klaproth, during the
analyses of zircon from Ceylon, noted an oxide that had not been pre-
viously described. The results of his study were published in 1789.
In 1824, J. J. Berzelius obtained a black impure zirconium powder,
but nearly pure zirconium metal was not produced until 1914.
In 1922, zirconium was found to contain a small proportion of the
element of atomic number 72. This element is so nearly identical to
zirconium that no qualitative differences in chemical behavior between
the two elements have been found up to the present time. In January
1923, von Henesy announced the discovery of element 72, and he called
it hafnium. Until recently, only a small quantity of pure hafnium
was produced. In recent years satisfactory, though still costly, large-
scale separations of zirconium and hafnium have been made. Hafnium
is not removed from the zirconium metal and zirconium compounds
used by industry. For all purposes other than use in atomic reactors
and research, the hafnium content is ignored because of the extreme
similarity of the two elements.
The United States production of zirconium metal in 1963 was esti-
mated at 850 short tons. The United States production of zirconium
concentrates is confidential. There is no reported production of zircon
from California.
Occurrences of zircon have been noted in many placer gold deposits
in California (fig. 88) , but only one has yielded zircon on a commercial
basis. Small quantities of zircon were removed in a dragline gold
dredging operation in 1937 near Lincoln in Placer County. The con-
centration of zircon in California sands generally is too low to permit
450
MINERAL AND WATER RESOURCES OF CALIFORNIA
EXPLANAT ION
Che r 0 kee
Little Rock Creek
Wa I lace
P lace r V i I le
T r i n i dad
Nevada City
N. Fk. Ame r ica n R i ve r
Gold Run
Lincoln
Michigan Ba r
Pe s cade r 0
Po i nt Sal
Forks of Sal mon
Trinity River
Burnt Ra nch
Figure 88. California placer deposits containing above average zircon concen-
trations (modified after Day and Richards).
the commercial recovery of this mineral at the current prices and
with the limited western market.
Selected References
Blumenthal, Warren B., 1958, The chemical behavior of zirconium: New York,
D. Van Nostrand Co., Inc.
Day, D. T., and Richards, R. H., 1906, Useful minerals in the black sands of the
Pacific slope : 1905, U.S. Geol. Survey Alin. Res., p. 1175-1258.
Miller, G. L., 1954. Zirconium : New York, Academic Press, Inc.
Stinson, Melvin C, 1957, Zirconium and hafnium, in Mineral commodities of
California : California Div. Mines Bull. 176, p. 707-712.
U.S. Bureau of Mines, 1965, Commodity data summaries. Zirconium and hafnium,
p. 166-167.
o
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Bulletin,
Call Number:
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no ,191
N9 621224
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