TN 24 C3 A3 ■Ws STATE OF CALIFORNIA DEPARTMENT OF NATURAL RESOURCES MINERAL RESOURCES AND MINERAL PRODUCTION DURING 1947 BULLETIN 142 1949 DIVISION OF MINES FERRY BUILDING. SAN FRANCISCO LIBRARY COLLEGE Of AGRICULTURF DAVIS IJBRARV UWIVERSITY OF CALIFORNIA DAVIS STATE OF CALIFORNIA EARL WARREN, Governor DEPARTMENT OF NATURAL RESOURCES WARREN T. HANNUM, DirecUjr DIVISION OF MINES FERRY BUILDING, SAN FRANCISCO II OLAF P. JENKINS, Chief SAN FR-\NCISCO BULLETIN 142 JULY 1949 THE COUNTIES OF CALIFORNIA MINERAL RESOURCES AND MINERAL PRODUCTION DURING 1947 Prepared under the direction of OLAF P. JENKINS CONTRIBUTING AUTHORS Charles V. Averill Oliver E. Bowex, Jr. Fenelon F. Davis Clarence A. Logan Louis A. Norman, Jr. John C. O'Brien Reid J. Sampson Richard M. Stewart Henry H. Symons William E. Ver Planck LIDRARY UNIVERSITY OF CALIFORNTK DAVIS LETTER OF TRANSMITTAL To His Excellency The Honorable Earl Warren Governor of the State of California Dear Sir : I have the honor to transmit herewith Bulletin 142, The Counties of California — Mineral Resources and Mineral Production During 1947, prepared under the direction of the Chief of the Division of Mines, Olaf P. Jenkins. This bulletin represents the Division's annual publication on mineral statistics including, as a special feature, a summary of the mineral resources of each and every county in the state. For the first time all the essential features of mineral information concerning the separate counties have been assembled under one cover : general geologic features, mineral resources, significant mining activities during 1947, and mineral production. It is the first statistical bulletin which contains the results of the cooperative agreement entered into with the federal Bureau of Mines whereby the latter organization gathers and processes the production figures directlj^ from the producers. These figures, however, as they became available, have previously been released in the Division 's monthly pamphlet, Mineral Information Service. The general preparation of Bulletin 142 was done by Charles V. Averill, Supervising Mining Engineer of the State Division of Mines. Other contributing authors were Oliver E. Bowen, Jr., Fenelon F. Davis. Clarence A. Logan, Lewis A. Norman, Jr., John C. O'Brien, Reid J. Sampson, Richard M. Stewart, Henry H. Symons, and "William E. Ver Planck, Jr., all members of the staff of the Division of Mines. In number of different mineral substances produced, California stands first among the states of the Union. Each year at least 60 different kinds of minerals and rocks are produced commercially. In value of annual mineral production, California ranks third among the states, exceeded by Texas because of its large petroleum and natural-gas pro- duction, and by Pennsylvania because of its vast coal resources. While this bulletin features the counties of the state, it is intended that the next annual volume will emphasize the mineral commodities. In this way the public will be provided with two invaluable reference books on the commercial minerals of the state, which do not duplicate the order of presentation. Respectfully submitted, WARREN T. HANNUM, Director Department of Natural Resources February 1949 (S) CONTENTS Page LETTER OF TRANSMITTAL 3 PREFACE " PART 1, SUMMARY OF THE MINERAL RESOURCES OF CALIFORNIA 11 Introduction 11 Mineral substances produced in California during 1947 V.S Contributions of the counties to the mineral production of California 24 PART 2, MINERAL RESOURCES OF THE COUNTIES OF CALIFORNIA 29 Alameda County 29 Alpine County 32 Amador County 33 Butte County 35 Calaveras County 37 Colusa County 40 Contra Costa County 42 Del Norte County 44 El Dorado County __ 4.j Fresno County 49 Glenn County — 50 Humboldt County 51 Imperial County 52 Inyo County 54 Kern County 57 Kings County 59 Lake County 60 Lassen County 62 Los Angeles County 62 Madera County 65 Marin County 68 Mariposa County 69 Mendocino County 71 Merced County 72 Modoc County 74 Mono County T5 Monterey County 78 Napa County 80 Nevada County 83 Orange County 85 Placer County 88 Plumas County 90 Riverside County — 92 Sacramento County 94 San Benito County 97 San Bernardino County 99 San Diego County 102 San Francisco County 105 San Joaquin County 107 San Luis Obispo County 110 San Mateo County HI Santa Barbara County 113 Santa Clara County IL' Santa Cruz County 118 Shasta County 119 Sierra County 121 Siskiyou County 123 Solano County 125 Sonoma County 127 Stanislaus County 129 Sutter County 131 (4) CONTENTS— Continued Page Tehama County 132 Trinity County 133 Tulare County 135 Tuolumne County 136 Ventura Countv 140 Yolo County 142 Tuba County 144 PART 3, DIRECTORY OF MINERAL PRODUCERS, DEALERS, AND COMMERCIAL LABORATORIES 147 Directory of producers of metallic and uonmetallic minerals in California during 1947 148 List of smelters and mineral dealers reporting purchase of California metals produced in 1947 192 List of mineral dealers, custom mills, and commercial grinding plants in California 193 List of quicksilver buyers 195 List of commercial assay and testing laboratories ^ 196 ILLUSTRATIONS Figure Figure 1. Mineral production in 1946 of the five leading states 12 Plates Plate 1. Map of California showing the distribution of principal mineral resources In xwcket 2. Total mineral production, including oil and gas, of five leading counties of California In pocket 3. Mineral production, excluding oil and gas, of seven leading coun- ties of California In pocket 4. Commercial minerals of California In pocket 5. Harvesting salt, Leslie Salt Company, Mt. Eden plant, Alameda County 28-29 6. California Pottery Company, Niles Plant, Alameda County 28-29 7. Darwin Hills, lead mining camp of Darwin in center, Inyo County 28-29 8. A, Long Beach Salt Company, Kern County. B, Pacific Coast Borax Company, Kern County 28-29 9. A, Monolith Portland Cement Company, Kern County. B, Close-up of loader mining gypsite, HoUoway gypsum deposit, Kern County 28-29 10. Eagle Mountains iron mine. Riverside County 28-29 11. Loading limestone for suyar-beet industry. Essential Industries Inc., San Luis Obispo County 28-29 12. Coronado Copper and Zinc Company, Shasta County 28-29 Tables Table 1. Mine production of gold in California during 1947, by counties 16 2. Natural gas production in California during 1947, by counties 19 3. Petroleum production in California during 1947, by counties 20 4. Mine production of silver in California during 1947, by counties 22 5. Quantity and value of mineral substances produced in California during 1946 and 1947 25 6. Mineral production of California during 1947, by counties 27 7. Mineral production from Alameda County during 1947 32 8. Mineral production from Amador County during 1947 35 9. Mineral production from Butte County during 1947 37 10. Mineral production from Calaveras County during 1947 40 11. Mineral production from Colusa County during 1947 42 12. ^Mineral production from Contra Costa County during 1947 44 (5) ILLUSTRATIONS— Continued Page 13. Mineral pruduction from Del Norte County during 1947 45 14. Mineral production from El Dorado County during 1947 49 15. Mineral production from Fresno County during 1947 50 16. Mineral production from Humboldt County during 1947 52 17. Mineral production from Imperial County during 1947 ^ 54 18. Mineral production from Inyo County during 1947 57 19. Mineral production from Kern County during 1947 59 20. Mineral production from Kings County during 1947 60 21. Mineral production from Lake County during 1947 62 22. Mineral production from Los Angeles County during 1947 64 23. Mineral production from Madera County during 1947 67 24. Mineral production from Mariposa County during 1947 71 25. Mineral production from Modoc County during 1947 75 26. Mineral production from Mono County during 1947 78 27. Mineral production from Monterey County during 1947 80 28. Mineral production from Napa County during 1947 83 29. Mineral production from Orange County during 1947 87 30. Mineral production from Placer County during 1947 89 31. Mineral production from Plumas County during 1947 91 32. Mineral production from Riverside County during 1947 93 33. Mineral production from Sacramento County during 1947 97 34. Mineral production from San Benito County during 1947 98 35. Mineral production from San Bernardino County during 1947 101 36. Mineral production from San Diego County during 1947 105 37. Mineral production from San Joaquin County during 1947 110 38. Mineral production from San Luis Obispo County during 1947 111 39. Mineral production from San Mateo County during 1947 113 40. Mineral production from Santa Barbara County during 1947 115 41. Mineral production from Santa Clara County during 1947 117 42. Mineral production from Santa Cruz County during 1947 119 43. Mineral production from Shasta County during 1947 121 44. Mineral production from Sierra County during 1947 123 45. Mineral production from Siskiyou County during 1947 124 46. Mineral production from Solano County during 1947 127 47. Mineral production from Sonoma County during 1947 128 48. Mineral production from Stanislaus County during 1947 131 49. Mineral production from Trinity County during 1947 135 50. Mineral production from Tulare County during 1947 136 51. Mineral production from Tuolumne County during 1947 139 52. Mineral production from Ventura County during 1947 142 53. Mineral production from Yolo County during 1947 143 54. Mineral production from Yuba County during 1947 145 (6) PREFACE It has long been the practice of the Division of Mines to issue eaeli year a statistical bulletin known as Miueral Production of California. This bulletin has always included much more information than merely that of mineral statistics. Short descriptions of the mineral commodities and the counties which produce minerals have always been included. Generally a list of the mineral producers and other pertinent data have been added. This year special emphasis has been placed on the mineral resources of the 58 counties in California, each of which have contributed to the mineral wealth of the state. General geologic features, occurrences and production of minerals, and principal mining operations are the sub- jects discussed. Statistical data are also added to these descriptions, mak- ing the whole volume a text to the mineral resources of the state by counties. Part 1 consists of a brief summary of the mineral commodities in the state, with a table showing the quantity and value of each of the mineral substances produced. In addition, a statement and table are given to show the total value of minerals produced in each county. Sev- eral graphs are included to indicate relationship between California and other leading mineral-producing states and the relationship between the principal mineral-producing counties of California. Part 2 forms the bulk of the bulletin and is devoted to treating each county briefly in the following manner : General geologic features Mineral resources Significant activities during 1947 Table of mineral production Part 3 does not contain any descriptions but is intended to serve as a directory of mineral producers and to give useful lists of smelters, mineral dealers, custom mills, commercial grinding plants, buyers of quicksilver, assayers, and testing laboratories. It is intended that the annual statistical report for 1948 will describe in more detail the occurrences, uses, and production of mineral com- modities as such rather than by counties. In the following year, the bulletin may be devoted to marketing minerals. In this manner it is hoped that these annual mineral production bulletins will serve a lasting value as texts to all phases of the mineral resources and industry of the state. In preparing this bulletin, various members of the technical staff of the Division of Mines have contributed. The author for each section is indicated by his initials after the section. In order to improve the manner of gathering and assembling mineral statistics without duplication between federal and state agencies, an agreement has recently been made between the California State Division of Mines and the United States Department of the Interior, Bureau of Mines. The stati-stics of this bulletin are the result of this cooperative undertaking. (7) AGREEMENT This agreement made ami entered into this 1st day of May, 1948, between the United States Bureau of Mines and the Division of Mines of the State of California for cooperation in the collection of statistical data : In order to avoid duplication of requests for statistical information of mine and quarry operations, and also in order that the State Division of Mines may be kept in touch with the mineral producers of the State, the following agreement between the Chief, State Division of Mines, and the Director of the United States Bureau of Mines is made for the collection of statistics of mineral production (with the exception of oil and gas) for 1947 and subsequent years. The type and scope of statistics to be secured from producers will be determined by consultation between the Bureau and the Division in order to comply with Section 2205(b) of the California Public Resources Code. As soon as possible after the first of December, in each year, a numbered list of the mineral producers in the State (a duplicate of the working list of the Federal Bm-eau of Mines) will be sent by the Bureau of Mines to the Chief, Division of Mines to be retained for his files. The Chief will check the data with the records of his ofiice and will notify the Federal Bureau of Mines at once of any additions and corrections to the list he deems advisable. These corrections will be made on the list of the Federal Bureau of Mines, properly numbered, and the Division of Mines will be advised of the list number given. The blanks for the collection of the statistical data from mineral producers will be printed at the expense of the United States Bureau of Mines and stamped "In coopera- tion with the Division of Mines, Department of Natural Resources, State of California, under Division 2 of the California Public Resources Code." The statistical inquiries will be mailed from the United States Bureau of Mines. The second statistical inquiry will be prepared in the Federal Bureau of Mines in the same manner as the first inquiry. The third will be sent by registered mail. This procedure will be so scheduled as to provide annually for receipt by Bureau of Mines, by March thirty-first, of all statistical reports from minei-al producers. If this procedure does not produce satisfactory results, the Chief, Division of Mines, will endeavor to induce delinquent respondents to cooperate in the Federal Bureau's voluntary statis- tical collection program, by personal visits of himself or his assistants or by such other means as he may deem advisable. The returns from the operators will not be forwarded through the Division of Mines but will be received by the Federal Bureau of Mines direct from the operators, provided, however, that the Chief, Division of Alines, may invoke his powers under Sections 2207 and 2208 of the California Public Resources Code, and may supply information so obtained to the Federal Bureau of Mines. The figures covering the total output of each mineral in the State, with such county break-down as is possible without revealing information obtained in confidence, will be sent to the Division of Mines as soon as the compilation of the data is completed. Figures representing the output of less than three producers shall not be disclosed, unless the Federal Bureau of Mines has obtained in writing authorization therefor from the producers interested. In publications relating to the minerals covered by this cooperative agreement, issued by either the Federal Bureau of Mines or the Division of Mines, proper credit for cooperation shall be given. The term of this agreement shall be from May 1, 1948 to April 30, 1953, inclusive, but shall be subject to termination by either party at any time during the term upon giving sixty days' written notice to the other party. Approved : Warren T. Hannum Director of Natural Resources State of California James Botd, Director U. S. Bureau of Mines Appro\t:d : Department of Finance James S. Dean, Director By Louis J. Heinzer Administrative Adviser Olaf p. Jenkins, Chief Division of Mines Department of Natural Resources State of California (8) MINERAL RESOURCES AND PRODUCTION 9 In order to make the production figures available to the public as quickly as possible, they have been published as they have been released, in the pamphlet Mineral Information Service published monthly by the Division of Mines. It is hoped that this new arrangement of releasing data as compiled and then assembling all data in a more comprehensive treatise on mineral resources will be found useful to both producers and users of the vast mineral reserves of this great State of California. Olaf p. Jenkins Chief, Division of Mines March 11, 1949 PART 1 SUMMARY OF THE MINERAL RESOURCES OF CALIFORNIA Page lutroduction 11 Mineral substances produced in California during I'.MT 13 Contributions of the counties to the mineral production of California 24 INTRODUCTION The growth of mineral industries always has been closely associated Avith the advance of civilization. The nations which have developed abun- dant mineral resources have been the most progressive and influential of the world. The use of minerals dates far back in the history of Man. First, stones were shaped into weapons, then mud and stones were used for the con- struction of crude huts. Xext it was discovered that some clays could be shaped, hardened by firing, and made into utensils. Later, metals were found, first in their native state, then as ores from which the metals were extracted. Still later it was found that the mineral coal could be used as fuel. Finally, petroleum was discovered. The discovery of mineral fuels has speeded the advance of industry more than any other event. It has given man luxuries and power and the means of attaining a high standard of living. California has a greater variety of minerals of possible commercial importance than any comparative area in the world. Mineral fuels — petroleum and natural gas — are found in the oil fields of the Los Angeles Basin, the southern coastal areas, and the southern San Joaquin Valley. Natural gas is also found in abundance in central and northern Cali- fornia. Coal is known to occur in several localities in the state, and was mined in the early days ; but at the present time, it is of little economic importance. Metals are widely distributed throughout the state. Gold, which set the record for production for many j'ears, was finally passed in value by petroleum in 1907. Other metals found in California ores in commercial quantities are quicksilver, copper, silver, tungsten, iron, chromium, man- ganese, lead, zinc, platinum-group metals, molybdenum, magnesium, and antimony. Industrial nonmetallic minerals are extremely abundant, and from them many of the industries of the state derive their raw materials. Among the more important commercial nonmetallic minerals are barite, diatomite, gypsum, limestone, pumice and pumicite, quartz, sulfur and pyrite, talc, soapstone, and pyrophyllite. California is fortunate in having several important occurrences of saline minerals. Borates come from the colemanite deposits of Death Valley, from the kernite deposits of the Kramer district, and from saline lakes in Inyo and San Bernardino Counties. Sodium salts are derived from desert lakes, iodine from oil-well brines, and salt from coastal bays and desert lakes. (11) 12 COUNTIES OF CALIFORNIA — 194;^ [Bull. 142 MINERAL PRODUCTION OF THE STAT ES LEADING IN 1946 i ! n i=irr Orr- TIT A. \U \! 'f \ 1 Q 1 / .TEXAS it If 1 'I ih If' H CALIFORNIA /^ txMW-' u. ILLINOIS jr // PENNSYLVANIA / i ,WESTi /VIRGINIA Figure 1. Mineral production of ttie five states leading in 1946. Texas leads because of oil and gas production ; Pennsylvania is second because of coal production ; California has the largest number of commercial minerals. MINERAL RESOURCES AND PRODUCTION 13 MINERAL SUBSTANCES PRODUCED IN CALIFORNIA DURING 1947 The total valne of the mineral output in California for the rear 1947 was $855,553,000, an increase of $263,259,000 over the 1946 total value of $592,294,000, as compiled b}^ the U. S. Bureau of Mines. The large increase in total value of the state's mineral output was chiefly brought about by an unprecedented demand for petroleum and natural pas and the resulting higher prices. A total of 53 commercial mineral substances was produced during the j'ear. All 58 counties of the state contributed to the production. Asbestos. All the asbestos produced during 1947 was of the amphi- bole variety and came from two properties in Shasta County and one in Placer County. The year 's output showed a decrease in both quantity and total value as compared with that of 1946. Asphalt (Native). Native asphalt produced during 1947 came from a single property in Santa Cruz County. The material being shipped is also referred to as bituminous sand, and it is used as road surface. The 1947 shipments showed a slight decrease in both quantity and value as compared with those of 1946. Barite. Shipments of barite from California deposits during 1947 came from single properties in Mariposa and Plumas Counties. The material from Mariposa County was used chiefly to give weight to oil-well drilling muds, and that from Plumas County was shipped to a plant at Modesto where barium chemicals are manufactured. Compared with that of 1946, the 1947 output showed a slightly smaller tonnage and a higher value. Barium pigments are manufactured from barite produced in Nevada. Boron Minerals (Borates). Shipments of borates from California deposits totaled 501,935 short tons valued at $11,844,108, and came from two properties in Inyo County, two properties in San Bernardino County, and one property in Kern County. In 1946 shipments totaled 430,689 short tons worth $9,575,866. The above figures include the sodium borates (kernite and kramerite) from Kern County; a small amount of cole- manite from Inyo County ; and crystallized borax prepared by evapora- tion of the brines at Searles Lake, San Bernardino County and Owens Lake, Inyo County. California is the leading source of the world 's borates supply. The 1947 output was the largest ever reported for the state. Bromine. The bromine produced in California during 1947 w'as recovered from sea-water bitterns from the salt works of San Francisco Bay and brines from Searles Lake, San Bernardino County. The chief use of the bromine is in the manufacture of ethjdene dibromide, which is used in tetraethyl lead for ethyl gasoline. The 1947 output showed an increase over that of 1946. Calcium Chloride. The calcium chloride produced in California during 1947 came from the salt deposits on Bristol Lake near Amboy, San Bernardino County, and totaled 7,968 short tons A'^alued at $111,950. The 1946 production was 9,979 short tons, worth $170,994. Carbon-Dioxide Gas. The carbon dioxide produced in California during 1947 came from wells near Niland, Imperial County; and wells near Hopland and Ukiah, Mendocino County. Nearly all the carbon dioxide was used in the manufacture of dry ice, and the year's output showed an increase in both amount and value over that of 1946. 14 COUNTIES OF CALIFORNIA 1 947 [Bull. 142 Cement. Cement was produced in California during 1947 from three mills in San Bernardino County and one mill in each of the follow- ing counties : Calaveras, Kern, Los Angeles, Riverside, San Benito, San Mateo, Santa Clara, and Santa Cruz. Production totaled 22,790,000 barrels in 1947, and 19,545,000 barrels in 1946. Shipments of cement in 1947 for the state totaled 22,846,458 barrels worth $46,539,749 ; for 1946, the total was 20,173,231 barrels worth $33,906,675. The annual capacity of California cement mills was increased from 25,770,000 bar- rels in 1946 to 26,070,000 barrels in 1947. In 1947 California was the leading state in the consumption of cement, and ranked second to Penn- sjdvania in cement production. Chromite. The chromite mined and shipped in California during 1947 came from single properties in Butte and Del Norte Counties. The 1947 output totaled 948 short tons and showed a slight increase over that of 1946. Clay. The clay sold or used in California totaled 1,950,076 short tons valued at $2,965,360 during 1947, and 1,670,305 short tons worth $2,254,164 during 1946. Of the 1947 production, 16,359 short tons worth $278,489 were kaolin and came from properties in Kern, Orange, and San Bernardino Counties ; 487,081 short tons worth $1,069,017 were fire clay and came from properties in Alameda, Amador, Los Angeles, Orange, Placer, Riverside, Sacramento, Santa Clara, and Stanislaus Counties; and 5,328 short tons worth $55,500 were bentonite and came from properties in Inyo, San Benito, San Bernardino, and San Diego Counties. A total of 1,441,308 short tons of miscellaneous raw clay valued at $1,562,354 was produced in Alameda, Calaveras, Contra Costa, Fresno, Humboldt, Inyo, Kern, Los Angeles, Marin, Placer, Riverside, San Ber- nardino, San Diego, San Joaquin, San Luis Obispo, Santa Barbara, Santa Clara, Santa Cruz, Sutter, and Ventura Counties. Part of the clay from Kern and Ventura Counties was used as oil-well drilling mud ; and part of the clay from Calaveras, Kern, Riverside, San Bernardino, Santa Clara, and Santa Cruz Counties was used in the manufacture of cement. Heavy clay products (other than pottery and refractories) pro- duced in California during 1947 had a total value of $16,793,000, as compared with $12,175,000 in 1946. Plants were operated in Alameda, Amador, Contra Costa, Fresno, Humboldt, Kern, Los Angeles, Marin, Orange, Placer, Riverside, Sacramento, San Bernardino, San Diego, San Joaquin, San Luis Obispo, Santa Barbara, and Santa Clara Counties. The largest production came from Los Angeles County where approxi- mately 24 plants manufactured these products ; the San Francisco Bay area ranked second in production with five plants in Alameda County, six plants in Contra Costa County, and four plants in Santa Clara County. Coal. During 1947 a small amount of lignite was produced from a mine at lone, Amador County, and was sent to a new plant which extracts montan wax by a chemical process. Montan wax is used in pigments and as a waterproofing material. During the year some development work was done on coal properties at Dos Rios, Mendocino County. Coke is made at a California iron and steel plant from coal imported from Utah. Copper. A total of 4,814,000 pounds of copper worth $1,010,940 was produced in California during 1947 ; the 1946 production was 8,480,000 MINERAL RESOURCES AND PRODUCTION 15 pounds worth $1,373,760. The Newton mine, operated by Pacific Mining Compan}^ near lone, Amador County, was the largest producer and, before it shut down on August 1, accounted for nearly one-third of the state 's output of copper. Other large producers during the year were the Penn mine of the Sha^vmut Copper Company, at Campo Seco, Calaveras County ; and the Hornet mine of the Mountain Copper Company, Ltd., at Matheson, Shasta County. By the end of July 1947, all copper-zinc mines in California suspended production because of the high cost of operation, the low grade of the ore, and the expiration of the government premium price plan. The average New York quotation on copper for the year 1947 was 20.9 cents per pound and that for 1946 was 14.4 cents ; the December 22, 1948, quotation on copper was 23.4 cents per pound. Diatomite. The quantity and value of diatomite shipped during 1947 were the largest for one year ever reported in the state. Diatomite was produced from single properties in Inyo, Los Angeles, Santa Barbara, and Siskiyou Counties. California leads all the states in the output of this mineral. Feldspar. During 1947 a small amount of feldspar was reported to have been shipped from a property in Madera County. No feldspar was produced in 1946. Fullers Earth. See bentonite under clay. Gem Stones. Some renewed activity was reported in the gem mines at Pala, San Diego County. A pocket yielding several pounds of gem- quality kunzite, and other smaller pockets were found. In Yuba County a small diamond was reported recovered from a gold placer. Gold. California produced 431,415 fine ounces of gold valued at $15,099,525 during 1947, and 356,824 fine ounces worth $12,488,840 during 1946. Of the 1947 gold output the lode or deep mines accounted for 118,877 fine ounces worth $4,160,695; the placer mines (mainly bucketline and dragline dredges) produced 312,538 fine ounces worth $10,938,830. Sacramento County led the counties in the value of gold yield for 1947 with a total of $3,974,600; Nevada County was second with a total value of $2,846,550; Yuba County third with $2,302,580; followed by Butte, Siskiyou, Stanislaus, and Merced Counties. The gold produced in Nevada County was derived in approximately equal amounts from the placers and the deep or lode mines, but production from the other leading counties was almost entirely from placer deposits. The following quotation from Merrill ^ gives an outline of gold mining activities for the year 1947 : "The Yuba Consolidated Gold Fields operated five dredges in the Yuba River district, Yuba County, during 1947, two in Butte County and one in Siskiyou County, which resumed operation in September following a shutdown since April 194G. The Natomas Co. operated their entire fleet of seven dredges in the Folsom district, Sacra raento County, during 1947. The Gold Hill Dredging Co. operated two dredges on the Mokelumne River, Camanche district, San Joaquin County, and one dredge on the Feather River, Oroville district, Butte County. Connected-bucket dredges were oper- ated also by the Merced Dredging Co. and the Snelling Gold Dredge Co., Snelling dis- trict, Pierced County ; by Thurman & Wright, Consumnes River district, and l)y the Capital Dredging Co. and the Lancha Plana Gold Dredging Co., Folsom district, Sacramento County ; by the Thurman Gold Dredging Co., Redding district. Shasta County ; by Yreka Gold Dredging Co., Klamath River district, and by the Junction 1 Merrill, Charles White, U. S. Bur. Mines, Mineral Market Report M.M.S. No. 1577, Jan. 30, 1948. IG COUNTIES OF CALIFORNIA 1 947 [Bull. 142 Table 1. Mine production of gold in Califoinia during IBIfl, by counties Mines producing! Gold County Lode Placer Fine ounces Value 8 3 13 1 13 1 11 10 11 4.724 27.037 5,171 6 2,994 235 139 1,974 6,228 1 48 197 6.363 16.422 41 81.330 5,358 546 30 113,560 4,409 13 4 18.256 13.263 .39,141 13.905 4.232 65.788 $165,340 Butte. -- - __.. 946,295 Calaveras 180,985 210 El Dorado -- _ . 12 3 1 104,790 Fresno 8,225 4,865 Inyo Kern 41 16 1 69,090 6 217,980 35 4 4 5 3 1,680 6,895 15 222,705 574,770 2 11 4 4 2 24' 1 1,435 Nevada Placer Plumas — Riverside Sacramento 14 25 7 1 14 2 2.846.550 187,530 19,110 1,050 3,974,600 154,315 455 1 7 10 24 20 5 10 140 6 12 9 2 19 2 638,960 Sierra 464,205 1.369,935 486,675 148,120 "i uba 2,302,580 Total: 1947 210 210 431,415 $15,099,525 1 Excludes itinerant prospectors, snipers, liigh-graders, and others who gave no evidence of legal right to property. 2 Combined to avoid disclosure of indiridual output. City Mining Co., Junction City district, Trinity Coimty. An increasing number of placer operators used dragline equipment during 1947, but several failed to produce throughout the year. Several hydraulic operations were acti,ve during 1047. and gold was produced from the Morris Ravine drift mine, Oroville district, Butte County. Gold continued to be recovered in relatively minor quantity as a byproduct by several gravel companies. "Gold production at lode mines remained about the same in 1947 as in 1946 and the general outlook for this class of gold mining was not a bright one. Not only did many former producers fail to reopen but several, iucludiug the Argonaut Mining Co., Ltd., stopped maintenance work entirely at their mines with a view toward a perma- nent shutdown. Increasing costs of mining resulting in inability to operate profitably was the reason for such action. In 1946, lode gold derived from gold ores accounted for 92 percent of the total lode gold produced, and S percent was recovered from gold- silver ore and ores mined primarily for copper, lead, zinc, and other base metals. Pre- liminary figures indicate that the ratio was about the same in 1947. Nearly two- thirds of the gold from gold ore produced in California in 1947 was mined in the Grass Valley-Nevada City district, Nevada County, almost entirely by the Idaho Maryland Mines Corporation and the Empire Star Mines Co.. Ltd., the latter company operated its mine at Grass Valley under a leasing system and accepted gold ore and precipitates for treatment at the company mill from other mines on a custom basis. In the Wash- ington district of Nevada County the Ancho-Erie Mining Co. was a substantial pro- ducer during 1947. In the Mother Lode Counties, the larger shipments of gold derived from gold ore were made by the Mount Gaines Mining Co., Hunter Valley district, Mariposa County, and the Eagle Shawmut Mine. Mother Lode district, Tuolumne County. The Eagle Shawmut mine was closed down permanently during the latter MINERAL RESOURCES AND PRODUCTION 17 part of the year and equipment was being sold. Burton Bros., Inc., cyanided gold ore from the Tropico mine, Mojave district, Kern County, and recovered a substantial quantity of gold. The Original Sixteen to One Mine, Inc., operated the Brush Creek mine, Dowuieville district. Sierra County, throughout the year. Of the mines that operated chiefly for base metal in 1947, only the Penn mine, Campo Seco district, Calaveras County, operated by the Shawmut Copper Mine Co., yielded more than 1,000 ounces of gold." Gypsum (Crude). The gypsum output in California during 1947 totaled 811,798 short tons valued at $1,996,157. It came from seven prop- erties in Kern County ; two in Riverside County ; and one property each in Fresno, Imperial, Kings, and Ventura Counties. The 1947 gypsum' production was the largest in both quantity and value ever reported in this state. In 1946, production of 574,345 short tons of gypsum worth $1,315,699 was reported. Most of the gypsum from Imperial and Riverside Counties was put to industrial uses and marketed in a manufactured form as plaster of paris and wall board ; gypsum from Ventura County went into the manu- facture of cement ; and gypsum from Fresno, Kern, and Kings Counties, and a small quantity of Riverside County production went into agricul- tural uses as soil conditioner. In California 490,268 short tons of gypsum was sold as an agricul- tural mineral in 1947.^ This was a considerable increase over the 24,218 short tons produced in 1937. Gypsum is used on the land to assist in granulating or breaking up heavy clay soils so that water can penetrate them and they may be more easily worked. Gypsum tends to neutralize alkali soils, and to convert sodium carbonate to sodium sulfate, which is less injurious to plant life. It also stimulates the decay of organic matter and supplies calcium and sulfur to the vegetation. Iodine. California is the only state in the nation in which iodine is produced. The 1947 output was the largest so far reported. Four plants in Los Angeles County, operated by two separate companies, extract this mineral from the waste water produced by oil wells. Iron Ore. Iron ore shipped during 1947 totaled 373,574 long tons from the Vulcan mine at Kelso and the Cave Canyon mine, both in San Bernardino County. It was reported that 226,062 long tons were shipped from these mines in 1946. The ore from the Vulcan mine went to the Kaiser Company's plant at Fontana to be reduced to pig iron and then made into steel. The ore from the Cave Canyon mine went to the River- side Portland Cement Company's mill at Crestmore to be used in the manufacture of high iron cement. In 1948 the Kaiser Company completed 51 miles of railroad from the Southern Pacific main line near Salton to the Eagle Mountain iron deposit in Riverside County, where production was under way in 1948. The Vulcan mine has been shut down. Kyanite. In 1947 there was no kyanite production. In 1946, a small tonnage was shipped from a property near Ogilby, Imperial County. The kyanite produced in California was used in refractories and electrical insulators. Lead. The lead produced in California during 1947 totaled 20,160,- 000 pounds worth $2,903,040 ; 1946 production was 19,846,000 pounds s Fertilizing materials: California Dept. Agriculture, Special Pub. 227, 1947. 2 — 4932 18 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 worth $2,163,214. Inyo County accounted for 17,980,000 pounds of the state's 1947 lead output. The Darwin mine at Darwin was the largest producer, and the Shoshone mines (Columbia No. 2) at Tecopa ranked second. Lead was also produced from Calaveras, El Dorado, Mono, San Bernardino, Shasta, and Sierra Counties during 1947. The average price paid the miner for lead during the year 1947 was 14.4 cents a pound compared with the 1946 price of 10.9 cents. The November 11, 1948, quotation. New York, for refined lead is 21.5 cents per pound. Lime. California sources produced during 1947 a total of 181,296 short tons of lime worth $2,615,599 ; during 1946 the output was 172,623 tons worth $2,144,712. The 1947 output of lime came from two plants in El Dorado, two plants in San Bernardino, and one plant each in Ala- meda, Monterey, and Tuolumne Counties. During 1947 California agriculture ^ consumed 13,280 tons of by- product lime, 1,182 tons of hydrated lime, and 18,533 tons of limestone, shells, and marl as soil conditioners ; as compared with the 1937 totals of 12,329 tons of by-product, lime, 475 tons of hydrated lime, and 3,017 tons of limestone, shells, and marl. These materials are used on the soil to correct acidity, to assist in granulating or breaking up heavy clay soils, to promote decay of organic materials, and to assist in the formation of calcium nitrate. Pulverized limestone is also used as a diluent or admix *in commercial fertilizers. Lithium Minerals. Lithium-sodium phosphate was produced from the brines of Searles Lake in San Bernardino County during 1947 and was the chief source of lithium salts in the nation for the year. Mag7iesite. During 1946 and 1947 the Westvaco Chemical Com- pany shipped a small amount of crude magnesite from the "Western Mag- nesite mine in Santa Clara County to their plant at Newark. It was mixed with magnesite from Nevada to make it meet the required specifications for certain refractory magnesium compounds. Magnesium. No production was reported for 1947. During 1946 an output of 56 tons of magnesium worth $21,644 was made by the Permanente Metals Corporation at Permanente, Santa Clara County, in its carbothermic reduction plant in an experimental operation. Magnesium Compounds (Natural). During 1947 a total of 40,000 short tons (MgO equivalent) of magnesium compounds worth $1,784,000 was produced; the 1946 total was 55,953 tons worth $2,814,979. Mag- nesium compounds were precipitated from sea water or from salt-w^orks bitterns and came from three plants on San Francisco Bay, one on Monterey Bay, and one on San Diego Bay. The plants at Newark, Alameda County, and Moss Landing. Monte- rey County, produce magnesium compounds for refractories and oxy- chloride cement; the plant at South San Francisco produces pharma- ceutical-grade magnesium carbonates, hydroxide, and oxide; the plant at Redwood City, San Mateo County, makes magnesium carbonate for insulation; and the one near San Diego, San Diego County, produces magnesium chloride. Mercury ( Quicksilver). Mercury produced from California ore during 1947 totaled 17,165 flasks of 76 pounds worth $1,437,397, as com- * Fertilizing materials: California Dept. Agriculture, Special Pub. 227, 1947. MINERAL RESOURCES AXD PRODUCTION 19 pared with the 1946 total of 17,782 flasks worth $1,746,904. The 1947 output came from 25 properties located in Fresno, Lake, Napa, San Benito, San Luis Obispo, Santa Clara, and Yolo Counties. Approximately 90 percent w^as produced from three mines — the New Idria in San Benito County, the Mount Jackson in Sonoma County, and the Keed in Yolo County. In 1947 California accounted for approximately 75 percent of the nation 's output of mercury. Prices on mercury fell throughout the year and were the lowest since January 1939. The average price of mercury at New York for the year 1947 was $83.74 per flask compared with the 1946 price of $98.24 per flask. For the first 3 months of 1947 New York quotations averaged $87.24 per flask, and for the last quarter of the year they averaged $79.78. Mica. During 1947 sericite mica was mined and shipped from a property near Ogilby, Imperial County, which has been operating almost continually since 1929. The material is ground and used for roofing paper, as a foundry facing, in stucco paint, and for decorative purposes to create the appearance of snow. Mineral Water. "Water from springs or artesian wells, bottled, in part artificially carbonated, and sold in 1947, was produced from properties in Butte, Calaveras, Contra Costa, Lake, Los Angeles, Marin, Napa, Orange, Riverside, San Benito, San Bernardino, San Diego, San Francisco, San Luis Obispo, Santa Barbara, Shasta, Siskiyou, Sonoma, and Tehama Counties. Health and pleasure resorts are located at many of the hot springs through the state. The water from some of the hot springs is not suitable for drinking but is excellent for baths. Mohjhdenum Ore. Molybdenum concentrate has been made at the mill of Lf^nited States Vanadium Corporation on Pine Creek, near Bishop, Inyo County, as a by-product from tungsten ore. Natural Gas. Total value of natural gas production in California was second only to petroleum during 1947, and came from properties in 20 counties. The output was 544,950,000 M cu. ft. valued at $55,694,000 at the well, as compared with the 1946 total of 487,904,000 M cu. ft. worth $36,056,000. The quantity and value of the 1947 output were the largest of any year so far reported for the state. The average amount received for natural gas at the well during 1947 was 11 cents per M cu. ft. ; the 1946 price was 7.4 cents per M cu. ft. Table 2. Natural gas production in California during 194^, iy counties County M. cu. ft. Value Fresno Kern Kings Los Angeles Orange Sacramento San Joaquin Santa Barbara Solano Ventura Butte, Contra Costa, Glenn, Humboldt, Madera, Stanislaus, Sutter, Tulare, Yolo Totals 63,814,000 86,289,000 39,972,000 95,702,000 29,399,000 72,883,000 9,650,000 18,070,000 65,411,000 46,140,000 17,620,000 $6,750,000 8,329,000 4,282,000 8,348,000 2,465,000 8,357,000 1,261,000 1,317,000 8,155,000 4,392,000 2.038,000 544,950,000 $55,694,000 20 COUNTIES OF CALIFORNIA 1947 [BuU. 142 Natural-gas gasoline produced during 1947 in plants operating in oil fields of Fresno, Kern, Kings, Los Angeles, Orange. Santa Barbara, and Ventura Counties, totaled 837,313,000 gallons valued at $45,812,000 ; the 1946 production was 734,227,000 gallons worth $32,085,000. Liquefied petroleum gases produced during 1947 totaled 233,546,000 gallons worth $8,174,000, from plants in the same counties mentioned above as producing natural-gas gasoline. Total 1946 production was 176,311,000 gallons worth $4,933,000. Peat. Peat is mined on the islands in the delta of the Sacramento and San Joaquin Rivers in Sacramento, San Joaquin, and Contra Costa Counties ; from dry lakes in the northeast corner of the state in Modoc County; and from Orange and Santa Cruz Counties. The material is used as a soil amendment and mulch. Pehhles for Grinding. Grinding-mill pebbles were produced in California during 1947 from the beach at Carlsbad, San Diego County. Perlite. Several perlite-expanding plants are operating in Cali- fornia, but during 1947 they received all their crude perlite from out of the state. In 1948 shipments of crude perlite from Napa County were made to an expanding plant at Campbell. Crude perlite from a deposit near Big Pine, Inyo County, was shipped to plants in the Los Angeles area and to plants in the East. A small tonnage of crude perlite was also shipped from Modoc County. Deposits of perlite are known to exist in several counties, and probably more will be found in the near future. Petroleum. California ranks second to Texas, among the states, in the quantity and value of its petroleum output. The 1947 output of crude oil was the largest ever produced in the state both in amount and value, and totaled 333,102,000 barrels worth $571,688,000. Petroleum accounted for approximately 67 percent of the value of the state's mineral output for 1947. In 1946, 314,713,000 barrels of petroleum, worth $387,100,000, was produced. Table 3. Petroleum production iti California during 1947, hy counties County Barrels i Value Fresno ----- 44,133,000 ! S75,3S8,000 Kem 106,048,000 j 176,360,000 Kings 7,503,000 i 15,482,000 Los Angeles 91,889,000 ; 164,122,000 Orange : 34,146,000 58,274,000 Santa Barbara ' 22,463,000 33,221,000 Ventura ' 26,858,000 I 48,750,000 Monterey, San Bernardino, San Luis Obispo, Santa Clara ' 62,000 | 91,000 Totals 333,102,000 ' §571,688,000 Prices quoted on California crude oil during 1947, effective March 19, were increased 20 cents per barrel on aU gravities, and on July 1 an additional 20 cents per barrel increase was granted; on October 28 a 10 cents per barrel increase on all gravities was made ; on December 1 one oil company granted a 40 cents per barrel increase ; and on December 27 all other crude oil purchasing companies made a 50 cents per barrel increase on aU grades of petroleum. The price of aU grades of petroleum in all fields through the state increased $1.00 per barrel during the year, and the heaviest gravity oils in Santa Barbara County more than doubled in price. MIXERAL RESOURCES AND PRODUCTIOX 21 Phosphate Rock. No phosphate rock is mined in California, but a considerable amount of phosphate rock and super-phosphate is shipped into the state for making fertilizers. Before being sold to the farmer, most of the phosphate rock is converted into super-phosphate or thermo- phos. In the past a very small tonnage was used without treatment, but in 1947 no crude phosphate rock was sold as a soil conditioner. Two plants in the state, one at Kichmond and the other at Vernon, manu- facture super-phosphate; a plant at Permanente makes thermo-phos. Plcttimim Metals. During 1946 and 1947 platinum-group metals were recovered in California by the gold dredges operating in Butte, Merced, Sacramento, and Yuba Counties. Much of the platinum pro- duced during the 2 years was held by the mining companies and not sold. A large percentage of iridium and osmium, and lesser amounts of rho- dium, palladium, and ruthenium are associated with the platinum recovered in this state. Potash. Potash salts are recovered from the brines of Searles Lake, San Bernardino County, at the plant of the American Potash and Chemical Corporation. As a result of a recent increase in capacity of the plant, the 1947 output was the largest ever reported. The potassium salts produced in the state are the sulfate and the chloride, which are used in commercial fertilizers. Potassium is one of the elements essential to plant life, and compared with most elements it is required in fairly large quantities. Pumice and Pumicite. California led the nation in shipments of pumice and pumicite during 1947, with 169,037 short tons worth $1,026,275. The 1946 total was 89,181 short tons worth $755,570. The 1947 output came from properties in Amador, Calaveras, Contra Costa, Inyo, Kern, Madera, Modoc, Mono, Napa, Siskiyou, and Sonoma Counties. All was lump pumice except that from Amador and Kern Counties and one Madera County property. Most of the pumice was used in light-weight aggregate, chiefly in concrete blocks and acoustic plaster. A small portion was used as an abrasive in both pumice grits and scour- ing blocks. The pumicite was utilized as a scouring agent in cleanser, in soap, and as a carrier for insecticides. Pyrite. For many years pyrite has been mined and shipped from the large massive Hornet mine deposit at Matheson, Shasta County. This material is shipped to two plants in the San Francisco Bay area and used in the manufacture of sulfuric acid. At one of these plants ore high in pyrite is roasted to produce sulfur-trioxide gas. The residue is shipped to a nearby smelter. A small amount of pyrrhotite from the Old Dominion mine in Orange County is being used as an agricultural mineral. Bolt. Salt is recovered by solar evaporation from the waters of San Francisco, Monterey, Newport, and San Diego Bays, and from dry lakes in Kern and San Bernardino Counties. Rock salt is mined from a prop- erty in San Bernardino County. During 1947 a total of 768,397 short tons of salt worth $3,810,898 was shipped from plants in the State. The 1946 total was 729,092 short tons worth $3,358,060. The material shipped during 1947 came from three properties in Alameda County ; two in San Bernardino County ; and one property each in Kern, Monterey, Orange, and San Diego Counties. Sand and Gravel. A total of 31,386,826 short tons of sand and gravel valued at $25,338,967 was produced in California during 1947. It came 22 COUNTIES OF CALIFORXIA- -194: [Bull. 142 from properties in 53 counties. The 1946 total of 27,220,849 short tons, worth $18,396,460, came from 54 counties. California's output exceeds that of any other state. All counties have contributed at some time, although in several counties no output has been reported for a number of years. Included under this heading are molding sand and glass sand which came from properties in Contra Costa, Los Angeles, Monterey, Orange, Riverside, Sacramento, San Diego, San Mateo, and Ventura Counties. Silica (Quartz). During 1947 vein quartz was shipped from single properties in Kern and Mariposa Counties ; and ganister from one prop- erty in San Bernardino County. Most of the quartz was used in the manufacture of refractories. Serpentine. In 1946 the Permanente Metals Corporation at Perma- nente, began to manufacture a fertilizer called thermo-phos in which serpentine produced near Almaden, Santa Clara County, and phosphate rock were fused. Silver. Silver produced in California during 1947 totaled 1,597,442 fine ounces worth $1,445,685 ; the 1946 total was 1,342,651 fine ounces worth $1,084,862. The price fixed by the United States Treasury for newly mined silver during 1947 was $0.905 ; the 1946 price was $0.808 ; and the 1940-45 price was $0.7111. Table Jf. Mine production of silver in California during 1947, by counties Mines producing! Silver County Lode Placer Fine ounces Value Amador Butte 8 3 13 1 13 1 11 10 11 11,598 2,201 97,076 3 2,039 37 22 1,235,998 7,686 6 6 57 1,933 1,505 7,323 25,744 807 570 15 6,203 103,877 6 $10,496 1,992 Calaveras 87,854 3 El Dorado . 12 3 1 1,845 Fresno Humboldt 33 20 41 16 1 1,118,578 Kern 6 6,956 5 4 4 5 3 5 Madera _ 52 15 1,749 Merced 1,362 Mono .. . _ _ 2 11 4 4 2 6,627 Nevada Placer 14 25 I 14 2 23,298 730 516 Riverside- - 14 5,614 San Bernardino San Diego _- - 24 1 94,009 5 1 7 10 24 20 5 10 6 12 9 2 19 2 78,427 2,501 4,343 1,677 2,015 3,767 70,977 2,263 Siskiyou and St-anis'a'iS^ 3,931 Trinity Tuolumne Yuba 1,518 1,824 3,409 Total: 1947 210 210 1,597,442 $1,445,685 1 Excludes itinerant prospectors, snipers, high-graders, and others who gave no endence of legal right to property. 2 Combined to avoid disclosure of indiridual output. MIXERAL RESOURCES AND PRODUCTIOX 23 Most of the silver produced in California is a by-product from the mining of gold, copper, lead, and zinc. The following paragraph is quoted from Merrill : "* "California was the sixth largest silver producing state in 1947 ; its output rose 22 percent and was the largest since 1941. Three-fourths of the 1947 total was derived from argentiferous lead and zinc-lead ores. The principal producers of such ores were the Anaconda Copper Mining Co., operating the Darwin mines, Coso district, and the Shoshone mines (from July 1, 1947), Resting Springs district, Inyo County, and the Finley Co., which operated the Shoshone mines (Columbia No. 2) during the first half of 1947. Other large silver producers were : The Shawmut Copper Mine Co., Penn mine (closed July 1947), Campo Seeo district, Calaveras County (zinc ore) ; Frank W. Royer, Kelly mine, Randsburg district, San Bernardino County (gold-silver ore) ; Louis Warnken, Jr., operating in the Calico district, San Bernardino County ; and the Mountain Copper Co., Ltd., Hornet Mine (closed June 1947), Flat Creek district, Shasta County, (zinc-copper ore). Much of the remainder of the silver produced in California during 1947 was derived from other base-metal ores." Slate. Slate mined in California during 1947 came from properties in El Dorado, Mariposa, Placer, and Tuolumne Counties. Slate pro- duced in El Dorado and Inyo Counties was used for roofing granules, for slate flour for fillers in linoleum, and for plastics. The remainder was sold for flagstone and stepping stones. Sodium Salts. California is the chief source of natural sodium salts in the nation. Soda ash, trona, and salt cake were produced during 1947 from three properties on Owens Lake, Inyo County, and two properties on Searles Lake, San Bernardino County. The production from Owens Lake was chiefly soda ash with a small amount of trona ; the production from San Bernardino County consisted of about equal amounts of soda ash and salt cake. The quantity and value of the 1947 output were the largest so far reported in the state. Reported during the year were 293,051 short tons of soda ash and trona worth $5,862,178. Stone. Stone includes granite, limestone, sandstone, crushed rock, rubble and riprap. It was quarried in 47 California counties during 1947 and totaled 12,757,790 short tons worth $13,012,556 ; the 1946 total was 8,950,320 short tons worth $8,452,083. Granite — chiefly monumental stone — is produced from quarries in Fresno, Lassen, Placer, Riverside, San Bernardino, and San Diego Counties. Limestone used for burnt lime, in sugar refining, in metallurgical and chemical plants, as a soil condi- tioner, in poultry grits and stock feed, and in treating water, came from properties in El Dorado, Fresno, Inyo, San Bernardino, San Mateo, Santa Clara, Santa Cruz, Tuolumne, and Ventura Counties. The produc- tion from San Mateo County and part of the production from Santa Clara County consisted of shells dredged from San Francisco Bay. A small amount of sandstone was quarried and sold as flagstone, or was used in garden walls, barbeque pits, fire places, and in Spanish- and English-type houses for effect. This production came from Monterey, Napa, and Santa Barbara Counties. Crushed rock, rubble, and riprap have been quarried from prop- erties in every county of the state at one time or another. Heavy construc- tion such as dams, reservoirs, air fields, and highways, greatly stimulate the production of these materials. Strontium Minerals. Celestite and strontianite were mined in Cali- fornia from 1939-46, from properties in Imperial and San Bernardino Counties. No shipments were reported in 1947. * Merrill, Charles White, Mine Production of Silver in the United States : U. S. Bur. Mines, Mineral Market Rep. 1578, Feb. 7, 1948. 24 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 Sulfur. During 1947 shipments totaling 698 long tons of sulfur -worth $9,074 were made from a property in Inyo County ; the 1946 total was 757 long tons worth $11,835. In Alpine County development work was done on a sulfur property and shipments were expected to start in 1948. Soil sulfur ^ amounting to 23,519 tons was sold in California during 1947, as compared with the 1937 sale of .2,517 tons. Nearly all the soil sulfur sold in the state was brought in from other states. It was used to increase acidity of alkaline soils. Where soils contain sulfur, the vegetation is much greener than otherwise. Sulfur is also said to modify bacteria in the soil. Sulfur in the form of sulfuric acid is used in the manufacture of many commercial fertilizers. Sulfur is also used as a fungicide in many agricultural sprays and dusts. Talc, Pyrophyllite, and Soapstone. During 1947 California shipped 91,537 short tons of talc, pyrophyllite, and soapstone worth $1,595,422, as compared with the 1946 total of 78,170 tons worth $1,434,978. The materials mined in 1947 were talc from properties in Inyo and San Ber- nardino Counties ; pyrophyllite from properties in Mono and San Diego Counties; and soapstone from properties in El Dorado and Tuolumne Counties. Titanium Minerals. Titaniferous magnetite containing ilmenite was mined and shipped from Sand Canyon, Los Angeles County, during 1947, Part of this material was used as granules on prepared roofing material ; the remainder went to a new pilot plant built to manufacture titanium pigments. Tungsten Concentrates. During 1947 there were reported shipped in California 394 short tons of 60 percent WOs tungsten concentrates worth $548,233. The 1946 total was 1,262 short tons of 60 percent WO3 concentrates worth $1,117,855. Material shipped during the year came from properties in Alpine, Fresno, Inyo, Kern, Madera, Mono, San Ber- nardino, and Tulare Counties. Zi7ic. The recoverable zinc produced in California during 1947 amounted to 10,830,000 pounds worth $1,310,430; the 1946 total was 13,754,000 pounds worth $1,677,988. The 1947 output came from copper- zinc mines in Calaveras, El Dorado, and Shasta Counties ; and lead-zinc mines in Inyo and San Bernardino Counties. All the copper-zinc mines in the state suspended operations on or before July 1, 1947. The average price of prime western grade slab zinc for 1947, East St. Louis, was 10.5 cents per pound ; compared with average weighted value of 11.7 cents per pound in 1946, including United States Govern- ment premium. Present quotation (December 22, 1948) East St. Louis, is 17.5 cents per pound. CONTRIBUTIONS OF THE COUNTIES TO THE MINERAL PRODUCTION OF CALIFORNIA The State of California has a population of 10,264,400 « and a total area of 158,297 square miles. The latter comprises a land area of 156,803 square miles and a water area of 1494 square miles, divided into 58 counties. The smallest county, San Francisco, contains an area of 45 square miles; the largest county, San Bernardino, contains an area of 5 Fertilizing materials: California Dept. Agriculture, Special Pub. 227, 1947. « State Chamber of Commerce, personal communication, January, 1949 . . . U. ». Dept. of Commerce, Bur. Census, 16th Census of the U. S., Population California, 1st series, 1941. MINERAL RESOURCES AND PRODUCTION 25 Table 5. Quantity and value of mineral suistances produced in California during 19^6 and 1947 The following figures for both 1946 and 1947 are supplied by the United States Bureau of Mines, with which the California State Division of Mines has a cooperative agreement for the collection of these statistics, starting with the year 1947. Mineral product 1946 Quantity Value 1947 Quantity Value short tons do do do do pounds do short tons barrels short tons Arsenious oxide Asbestos Asphalt (native) Barite Boron minerals Bromine Calcite (Iceland spar). Calcium chloride Cement Chromite Clay: Products heavj- clay (other than pottery and refractories) Raw short tons Coke do Copper pounds Diatomite short tons Feldspar (crude) long tons Ferro-aUoys short tons Fullers earth do Gem stones Gold troy ounces Gypsum (crude) short tons Iodine pounds Iron: Ore long tons Pig short tons Kyanite do Lead do Lime do Lithium minerals do Magnesite do Magnesium do Magnesium compounds (from sea water) ' short tons MgO equivalent- Mercury flasks (76 pounds) Mica, scrap short tons Mineral waters gallons sold Molybdenum pounds Natural gas (estimated value at wel M cu. ft. Natural gasoline and allied products : Natural gasoUne and cycle prod- ucts gallons Liquefied petroleum gases do Ores (crude) etc.: Copper short tons Dry and siliceous (gold and silver) short tons Lead do Zinc do Zinc-copper do Zinc-lead do Peat do Pebbles for grinding do Petroleum barrels Platinum metals (crude) troy ounces Potassium salts short tons Pumice do Pyrites long tons 430,689 9,979 20.173.231 51,670,305 260,470 8,480.000 7,414 356,824 .574,345 226.062 344,024 9,923 172,623 56 55,9.53 17,782 Is) 487,904,000 734,227,000 176,311.000 86,297 335,657 57,330 45,043 99,176 4,264 8.1.37 74 314,71.3,000 67 I 89,181 $9,575,866 170.994 33,906,675 <12,175,000 62,254,164 1,373,760 12,488,840 1,315,699 2,163,214 2,144,712 21,664 2,814,979 1,746,904 36,056,000 32,085,000 4,933.000 105,242 927 387, 100,000 755,570 501,935 7,968 22,846,458 948 51,950,076 332,244 4,814,000 5,278 431,415 811,798 373,574 453,376 10,080 181,296 40,000 17,165 544,950,000 837,313,000 233,546,000 15,993 449,792 87,913 49,651 35,745 9,695 333,102,000 324 1 169,037 $11,844,108 111,950 46,539,749 <16,793,000 52,965,360 1,010,940 15,099,525 1,996,157 2,903,040 2,615,599 1,784,000 1,437,397 55,694,000 45,812,000 8,174,000 571,688,000 1,026,275 3—4932 26 COUNTIES 01'^ CALIFORNIA 1 947 [Bull. 142 Tahle 5. Quantity and value of mineral substances produced in California during 1946 and 194^ — Continued 1946 1947 Mineral product Quantity Value Quantity Value Salt (sodium chloride) - short tons Sand and gravel do Sand and sandstone (ground) do Silica (quartz) do Silver troy ounces Slate 729,092 27,220,849 1 1 1,342,651 3,358,060 18,396,460 1 1 1,084,862 1 1 1 98,452,083 3,726 11,835 1,434,978 1,117,855 1,677,988 25,336,529 592,294,000 768,397 31,386,826 1 1 1,597,442 3,810,898 25,338,967 1 1 1,445,685 1 Sodium carbonate (natural) short tons Sodium sulfate (natural) short tons Stone do Strontium minerals do 1 1 98,950,320 243 '■ ° 757 78,170 1,262 6,877 293,051 1 912,757,790 5,862,178 1 913,012,556 Sulfuric acid (60° B.)i»_ do Sulfui- ore long tons Talc, pyrophyllite, and ground soap- stone short tons Tungsten concentrates (60 percent WO3 basis) do Zinc do Miscellaneous!' . 698 91,537 394 5,415 '9,074 1,595,422 548,233 1,310,430 29,565,251 Total value, eliminating duplica- tions (rounded figures). -_ - 855,553,000 ''■ Value included with "Miscellaneous." 2 Figure not available. ^ No canvass. * Figures obtained through cooperation with Bureau of the Census. ^ Sold or used; value of clay used in cement and heavy clay pioducts is included here but is not included in total value for state. « Value not included in total value for state. ■^ Comprises all compounds from raw sea water and bitterns. Data for 1945-46 are not quite comparable with 1947 in that the former are on a gross-weight basis and include some compounds made from dolomite in combination with sea water. ® Not valued as ore; value of recoverable metal content included with the metals. 8 Exclusive of marble, value for which is Included with "Miscellaneous." ^^ From lead smelting. ^ Includes minerals indicated by "^" and "^", above. 20,131 square miles. Production of commercial minerals during 1947 was reported from every one of the 58 counties. The presence of numerous large oil fields within the boundaries of Kern, Los Angeles, Fresno, Orange, Ventura, and Santa Barbara Counties, and the resultant production of petroleum and natural gas, have placed these counties at the top of the list in value of mineral production. San Bernardino County occupies seventh place owing to the production of large quantities of cement, borates, potash, and soda. Production from the famous Kettleman Hills oil field and the Rio Vista gas field has placed Kings and Sacramento Counties in eighth and ninth places, respectively. Santa Clara County, in tenth place, is the locus of the largest cement mill in the world. Mineral production values in excess of a million dollars have been reported from 31 counties in 1947. Million-dollar production values were also recorded by one or more counties in 1947 for each of the following minerals : boron minerals, cement, diatomite, gold, iron ore, lead, natural gas, petroleum, potassium minerals, salt, sand ancl gravel, silver, sodium minerals, and stone. MINERAL liESOURCES AND PRODUCTION 27 San Bernardino Comity produced 22 different minerals in 1947 surpassing all counties in variety of mineral products. Diversification of products in other counties was reported as follows: Inyo, 18 minerals; Kern, 14 minerals ; Los Angeles, 13 minerals ; and Fresno, 12 minerals. Table 6. Mineral production of C alifornia during WJ^t, hy coun ties * County Value County Value S8,497,176 (1) 913,189 1,311,410 4,199,321 89,963 1,388,682 322,156 1,641,020 89,342,311 2383,043 316,364 907,843 6,596,468 208,445,916 24,601,000 107,232 71,828 202,764,633 237,072 461,179 301,938 '528,181 742,366 116.170 332,893 2,602,297 359,911 13,008,304 67,854,831 487,751 $261,100 Riverside - . 8,381,215 Sacramento San Benito. __-__ 14,103,144 Butte - - . - .- 2,497,069 36,699,909 CoIusa_ - - ..-. San Diego . .- . 1,882,394 (3) Del Norte— - 2,932,420 El Dorado _ _ _ . San Luis Obispo - - 396,393 San Mateo 5,334,024 Olfinn Santa Barbara -- 40,544,339 Santa Clara . 11,981,146 Imperial. _ - . Santa Cruz -- - - - 3,216,500 Shasta-. 2,271,226 Kern .._ 468,196 Siskiyou . - 1,170,971 8,302,751 Lassen Sonoma 1,050,051 1,112,357 Madera _ - - . Sutter . -- --- 110,789 Marin Mariposa Mendocino Tehama Trinity Tulare Tuolumne Ventura - (2) 561,555 1,500,551 901,067 ^lodoc - - -- 62,514,862 Yolo 261,428 Yuba- - -. 2,559,132 Napa Hea\'y clay products (not entirely separable by counties') State total (rounded) 15,605,828 855,553,000 * These figures are furnished by the United States Bureau of Mines in cooperation with the California State Division of Mines. 1 Output of Alpine County is included with Nevada County. 2 Output of Tehama County is included with Glenn County. ^ Output of San Francisco County is included with Mendocino County. * Figure shown represents value of heavy clay products (other than pottery and refractories) as reported by U. S. Bureau of the Census (§16,793,000), less value of raw clay sold or used for the manufacture of cement and hea\7 clay products ($1,187,172). a c 4—4932 Z " • ■ fi •f.'^^J'P, ^[^ « J ■^ * :t^ .r" \ 1 ^u-t r -.:,«g>-;*i^ DIVISION OF :\rixEs BULLETIN" 142, PLATE 8 A, LONG BEACH SALT COMPAXY, KERX COUXTY B, PACIFIC COAST BORAX COMPAXY, KERX COUXTY DIVISION' OF MIXES BULLETIN 142, PLATE 9 A. :M0X0LITH PORTLAND CEMENT COMPANY, KERN COUNTY B, CLOSE-UP OF LOADER MINING GYPSITE HoUoway gypsum deposit, Kern County Eh Q 5 Z o ^ 2 <: 3 'Jl ^ si MINERAL RESOURCES AND PRODUCTION PART 2 29 MINERAL RESOURCES OF THE COUNTIES OF CALIFORNIA Papre Alameda County 29 Alpine County 82 Amador County -- 33 Butte County oo Calaveras County 37 Colusa County 40 Contra Costa County 42 Del Norte County 44 El Dorado County : 45 Fresno County 41J Glenn County 50 Humboldt County 51 Imperial County 52 Inyo County 54 Kern County 57 Kings County 59 Lake County 60 Lassen County 62 Los Angeles County 62 Madera County 65 Marin County 68 Mariposa County 69 Mendocino County 71 Merced County 72 Modoc County 74 Mono County 75 Monterey County 7S Napa County 80 Nevada County 83 Page Orange County 85 Placer County 88 Plumas County 90 Riverside County ■ 92 Sacramento County 94 Sau Benito County 97 San Bernardino County 99 San Diego County 102 San Francisco County 105 San Joaquin County 107 Sau Luis Obispo County 110 San Mateo County 111 Santa Barbara County 113 Santa Clara County 115 Santa Cruz County 118 Shasta County 119 Sierra County 121 Siskiyou County 123 Solano County 125 Sonoma County 127 Stanislaus County 129 Sutter County 131 Tehama County 132 Trinity County 133 Tulare County 135 Tuolumne County 136 Ventura Couuty 140 Yolo County 142 Yuba County 144 ALAMEDA COUNTY General Geologic Features. Alameda is one of the central Coast Range counties, lying on the eastern shore of San Francisco Ba3^ It con- tains a land area of 733 square miles and supported a population of 735,000 in 1947. A northwest-trending alluvial plain of Quaternary age, 3 to 8 miles in width, constitutes the west border of the county. This plain rises from the tidal waters of the bay to an elevation of about 100 feet at its eastern inner margin. Here the Ilayward fault, a persistent zone of structural weakness, separates the plain from the uplifted Berke- ley Hills on the east. This is the dominant range in the uplifted block between the bay and Mount Diablo in Contra Costa County. Along its southwest flank the Franciscan formation of Jurassic age, composed of sandstones, shales, cherts, schists, and associated basic intrusives of peridotite altered to serpentine, is exposed. These rocks are overlain unconformably b}' Cretaceous sandstones and shales which extend over the summit of the range east of Hayward. The general dip of the Creta- ceous sediments is northeastward, and the}' are flanked on the east by strips of upper and middle Miocene marine sediments forming the west limb of a sj'iicline. The Miocene is in places covered by Pliocene sedi- ments of continental origin interbedded with volcanic flows. The headwaters of Arroyo Mocho, Arroyo Yalle, and Alameda Creek, which form the principal drainage system of the county, are located in the southeastern part, where the maximum elevation, about 3,800 feet, is attained. Surface exposures are rocks of the Franciscan formation, 5—4932 30 COUNTIES OF CALIFORNIA 1 947 [BulL 142 •which cover about 110 square miles. The streams flow northwest- ward to the Livermore Vallej'-, which covers about 70 square miles in the north-central part of the county ; thence westward through Niles canyon and across the alluvial plain, from which they discharge into the bay at Alvarado. The Franciscan-covered area slopes northwestward and is overlain by Quaternaiy-Pliocene gravels in the low hills which form the south border of the Livermore Valley. The Livermore Valley is bordered on the north by the southern tip of the Mount Diablo foothills where volcanic rocks of Pliocene age are exposed. It is closed on the east by the Altamont Hills along whose western base a probable fault has been mapped.'^ The surface near Altamont is covered by marine sandstones and shales of upper Cretaceous age which are anticlinal in structure. South of Township 2 South, the Cretaceous is overlain by upper Miocene marine sediments over a wide area, through which the Cretaceous occasionally appears in fault contact. The Miocene near Tesla is flanked on the south by a thin strip of upper Eocene marine sediments. On the west the Liver- more Valley is bounded by the Berkeley Hills, along whose eastern base the Calaveras fault has been mapped. Mineral Resources. Large resources of salines, sand, gravel, pottery clay, brick clay, and miscellaneous stone exist in Alameda County. Sodium chloride (the salt of daily usage) is the principal saline product, and is obtained by solar evaporation of sea water along the eastern shore of San Francisco Bay in the vicinity of Newark. Bitterns from the salt plants are the source of magnesium compounds. The production of magnesium compounds from sea water has largely replaced the use of maguesite as a source material for these products. Additional by-products of salt production are bromine and potash. Clay obtained from Quater- nary deposits of the Niles alluvial cone provides the raw material for ceramic and brick-making plants in the county. Small amounts of high- grade clays have been produced intermittently from the steeply dipping Eocene beds near Tesla. The excavation of sand and gravel from Quater- nary deposits at Niles and from Quaternary-Pliocene deposits in the Livermore Valley constitutes an important phase of the mineral indus- try of Alameda Count}^ In addition, numerous quarries for the produc- tion of crushed rock are distributed throughout the Berkeley Hills from central Oakland to Niles. Most of these quarries are located in the cherts and metamorphosed sandstone of the Franciscan formation. A small amount of chromite was produced at Cedar Mountain during the first world war. Coal classed as sub-bituminous was produced from the steep- dipping Eocene beds near Tesla. Over a 6-year period beginning in 1897 production averaged 70,000 tons annually. There has been practically no production of coal since 1902. Deposits of manganese associated with the cherts of the Franciscan formation southwest of Livermore produced small quantities of ore prior to and during World "War I. A small quan- tity of manganese ore was also produced during World War II. A mod- erate amount of pyrite was produced annuallj' from 1901-34. The pyrite occurred at Leona Heights in a narrow belt of rhyolite which extends through the hills from Berkeley to Decoto. The following commercial minerals are known to occur in Alameda County and production in small quantities has been reported: magnesite, limestone (bay shells), glass '• Huey, A. S., Geology of the Tesla quadrangle, California : California Div. Mines Bull. 140, 1948. MINERAL RESOURCES AND PRODUCTION 31 sand, asphalt, mineral paint, asbestos, travertine, soapstone, copper, lead, silver, and gold.^ Significant Activities During 1947. Clays from the Livermore Valley and from the Niles alluvial eone have been used for many years in the manufacture of sewer pipe, roofing tile, structural shapes, and other clay products. To obtain a working medium with the desired prop- erties, the local clays are usually blended with other clays "imported" from Calaveras and Amador Counties. Sea-water bitterns from nearby salt ponds are used at the Newark plant of the TTestvaeo Chemical Corporation in the manufacture of basic magnesium carbonate. This company also produces bromine in an adjoin- ing plant. Common salt, sodium chloride, is the chief saline product in Ala- meda County. It is obtained by solar evaporation of the waters of San Francisco Bay. Large quantities of water are pumped from the bay into intake ponds where the evaporation process begins. As the gravity of the solution increases it is moved along into concentrating ponds, and finally transferred into crj'stallizing ponds where the salt crystallizes out in a bed about 5 inches thick. About 2 years are required to complete the cycle. The ponds of the Leslie Salt Company cover an area of about 25,000 acres, fringing the southern end of San Francisco Bay. The actual deposition and harvesting of the annual salt crop occurs at Newark and Mount Eden in Alameda Count}^ The bed of salt is recovered by mechan- ical harvesting machines having a capacity of 125 tons per hour. These machines load trains composed of twelve 2-ton bottom-dump cars powered by 4-ton Vulcan gasoline locomotives running on lightweight movable narrow-gauge tracks. The salt is hauled to central washing plants, scrubbed in salt water to remove clay or dirt, and conveyed to the crude-salt storage pile. In the adjoining refinerj-, salt for human consumption is processed to the highest degree of purity in triple-effect evaporators. A small amount of naturally bonded moulding sand is produced from a steep-dipping 15-foot bed near the old Tesla coal mine. This sand is about 70 percent sand and 30 percent clay and is mined by under- ground methods. The crude material is run through a hammer mill, delivered to consumers, and used in synthetic facings for medium and heavy iron work. Stone for concrete aggregate, road surfacing, and fill material con- stitutes the largest item of mineral production in Alameda County. Numerous sand and gravel plants are located in the Livermore Valley and on the Niles alluvial cone. Caterpillar-mounted dragline excavators are usually employed to mine the gravel from open pits. This gravel is transported by trucks or belt-conveyor systems to nearby washing and screening plants where the pit-run gravel is crushed, washed, and graded to sizes suitable for concrete aggregate. At the crushed-rock quarries the bank-run material is shovel-loaded to trucks, transported to crushing plants, reduced, and sized. Some of the crushed rock products are washed, although washing is not required on road and fill material. F.F.D. 8 Laizure, C. McK, San Francisco field division — Alameda County : California Div. Mines Rept. 25. pp. 427-456, 1929. 32 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 Tahle 7. Mineral production from Alameda. County during 19Jf1 Product Quantity Value Clay products, heavy clay (other than pottery and refractories) Clay, raw Salt (sodium chloride) Sand and gravel Stone 18,751 short tons_ 540,943 short tons- 3,844,057 short tons. 1,112,500 short tons- Unapportioned (bromine, lime, and magnesium compounds crude magnesite. SI, 165,000 18,782 3,046,907 3,578,314 714,025 1,139,148 Total value. 58,497,176 1 According to U. S. Bureau of the Census; value not included in county total. ALPINE COUNTY General Geologic Features. Alpine County, located along the east- ern border of central California, a few miles south of Lake Tahoe, is an area of mountain peaks and ridges, cut by a few deep valleys. Maximum elevations are in the southeastern corner of the county, where Stanislaus Peak and White Mountain stand over 11,000 feet above sea level. The western part of the county is occupied almost entirely by the granitic rocks of the Sierra Nevada batholith, and the western boundary of the county parallels the north trending crest of California 's dominant mountain range. The Jurassic intrusives in the area are strongly fissured and jointed in contrast to the granitic rocks of the western slopes.^ Kocks of the western part of the county show ample evidence of the numerous glaciers which occupied present drainage areas in late Pleistocene time.^'^ Tertiary volcanics, essentially andesite, blanket a large portion of the eastern half of Alpine County and extend into neighboring Nevada. A few isolated patches of these volcanics are found in the western half. Silicifieation of the volcanics and resulting mineral deposition is pro- nounced in several sections, particularly in the area southeast of Markle- ville.^^ A few small outcrops of pre-Cretaceous metamorphics, including slates, schists, limestone, greenstone, and conglomerate are widely scattered throughout the county. They are embedded in the granite or granodiorite and have suffered regional and contact metamorphism.^^ Drainage of this high Sierra country is mainly through the East and West Forks of the Carson Eiver and their many tributaries. The East Fork rises in the south-central portion of the county and flows northward through the main volcanic-rock area into Carson Valley. The West Fork rises in the west-central part, flows northward, thence east- ward into the adjoining state. Headwaters of the Stanislaus and Mokel- umne Rivers drain the southwestern area. Grover's Hot Springs are situated near the southern terminus of a major fault which strikes northward and passes near Woodfords. Numerous large hot springs are located on this fissure along its northerly extension in Nevada. Where the escarpment crosses the West Fork of the Carson River, the gradient of the stream increases markedly downstream. 9 Lindgren, "Waldemar, The Tertiary gravels of the Sierra Nevada of California : U. S. Geol. Survey Prof. Paper 73, 226 pp., maps, 1911. " Blackwelder, Eliot, Glacial and associated stream deposits of the Sierra Nevada : California Div. Mines Rept. 28, pp. 303-310, 1932. uEakle, A.S., et al., Alpine County: California Min. Bur. Rept. 15, pp. 5-27, 1919. ^ Lindgren, W., op. cit MINERAL RESOURCES AND PRODUCTION 33 Mineral Resources. In spite of the variety of mineral occurrences which have been reported in Alpine County, including copper, lead, zinc, gold, silver, quicksilver, molybdenum, tungsten, limestone, mis- cellaneous stone and sulphur, production has been small. There are no important deposits of auriferous gravels. During the period of recorded mineral production from 1880-1947, the total value was less than $400,000, Prior to 1880 an estimated $1,000,000 in gold and silver was produced from the county. This period of productivity paralleled the Comstock Lode activity. Alpine County contributed heavily to the development of the Comstock Lode by furnishing mine timbers and fuel from its abundantly forested mountains. The most important mineralized area of the county is a few miles south and southeast of Markleeville, centering around the Mogul, Moni- tor, and Silver Mountain districts. Here the andesite has been extremely altered and silicified by ascending thermal waters. Subsequently complex ores of gold, silver, lead, zinc and copper were deposited. Sulphur in commercial quantities is found in the Leviathan mine, originally opened as a copper property, in the northeastern section of the mineralized area. The complex nature of the low-grade ores made beneficiation difficult in the early days and contributed to the decline in production. Some high-grade spots were encountered in the ore bodies, most of which were without definite walls, being impregnated masses of the altered andesite. No great depth was reached in the operations ; a great deal of the prospecting and development work was done through adits. In the Silver King district, 15 miles south of Monitor, auriferous pyrite occurs in a section of metamorphosed rocks (schists). Ten miles west of Markleeville, in the Blue Lakes and Hope Valley region, meta- morphosed sediments have been mined for gold, silver, copper, and tungsten. The latter occur in the contact-metamorphic ore bodies (tactite) in limestone in the Hope Valley section. Epithermal hiibnerite (manganese tungstate) has been found in the ore of the Zaca mine (silver) near Monitor.^^ Significant Activities During 1947. The mineral materials pro- duced in Alpine County during 1947 were confined to tungsten and miscellaneous stone (sand and gravel). The Alpine Mining Company (Wolframite mine) operated their tungsten deposit 3 miles north of Carson Pass in Hope Valley during the year. The ore was hauled to Minden, Nevada for concentration. At the Leviathan mine (copper- sulphur), the Siskon Mining Company continued rehabilitation of the mine workings. There was no production of gold and silver reported for the year. L.A.N. AMADOR COUNTY Geologic Features. Amador County is bounded by the South Fork of Cosumnes River on the north and Mokelumne River on the south. The land rises graduallj'' from the eastern border of Sacramento Valley on the west to the western summit of the Sierra Nevada. Most of the streams flow southwest and are tributaries of Mokelumne River. Extending northwest across the westernmost part of the county are Eocene sedimentary beds which are economicalh^ important because of the clay and lignite deposits found in them. These beds dip slightly to " Gianella, Vincent, Epithermal hiibnerite in the Zaca mine, Alpine County, Cali- fornia : Econ. Geology, vol. 3 3, no. 3, May 1948. 34 COUNTIES OP CALIFORNIA — 1 947 [BuU. 142 the west and cover the lower western bedrock slope which consists of a complex of amphibolite schist, Jurassic slate, and Carboniferous slate and schist. These tightly compressed and metamorphosed basement rocks strike uniformly northwest, dip steeply northeast and outcrop in a belt 8 miles wide. Some copper ore occurs in the amphibolite schist in the western part of the belt and the Carboniferous members contain many small deposits of hig-h-calcium limestone. Along the east border of this complex, a band of greenstone (meta-andesite) is in contact with the Jurassic clay slate of the Mother Lode. The slate and contact zone is traversed in a northwesterly direction by the Mother Lode reverse fault. The 10 miles of this fault zone which crosses Amador County has been most important in gold production. For 10 miles or more east of the Mother Lode the exposed rocks are principally the Carboniferous (Mis- sissippian) series of hard slate, schists and quartzite, penetrated in only a few places by outliers of the Sierra Nevada batholith, and capped here and there by remnants of volcanic debris which followed ancient stream courses flowing from the mountains which lie to the east. The most important deposits here are large beds of limestone, mostly undeveloped, at Volcano and near Fiddletown. Numerous small gold mines occur in the Carboniferous rocks and in the western part of the granitic batholith which adjoins them on the east. This is the East Belt, in which the ore bodies are smaller and ore more complex but frequently richer than in the Mother Lode. Mineral Resources. Amador County has been noted for its Mother Lode deposits of gold ore, which have been worked to a vertical depth of more than a mile below the surface. The lode-gold production of the Amador County has been second in California only to that of Nevada County. Next in importance are the claj^ deposits of the lone and Carbondale districts, where both open pits and underground mines have supplied for years a variety of clays from the lone (Eocene) beds. Part of the clay is highly refractory. One pottery is in operation in the county, but clay is shipped to many other plants in different parts of the state. Lignite was mined for many years prior to 1902 from deposits associated with the lone clay. Two lignite deposits are now being reopened. Limestone and marble are plentiful and have been produced in years past. Miscellaneous stone is produced for local use. Other min- erals produced in the past include asbestos, copper and copper ores, chromite, gem minerals (diamonds and clnysopal), manganese ores, by-product platinum, lead and silver (from gold and copper mining), Boapstone, silica sand, sandstone, and slate. Rock wool has been produced the past few years from old copper smelter slag. Significant Activities During 1947. The continued increase in labor and material costs has hampered resumption of gold-lode mining and prevented reopening of several mines. The Central Eureka mine at Sutter Creek was being rehabilitated during 1947. The Belden mine on the East Belt was the most important producer among the small mines in that region, where ores are in some cases rich enough to permit work even at present high costs. The Argonaut mine management has decided to dissolve the company because of present unfavorable conditions, and not due to the exhaustion of ore. In 50 years of operation, this mine produced more than $25,000,000 and paid $3,789,750 in dividends on MINERAL RESOURCES AND PRODUCTION 35 a capitalization of $1,000,000. The deepest level, at 6,300 feet inclined depth, is 5,570 feet vertically below the shaft collar, or 4,000 feet below sea-level. The Argonaut is the second deepest mine in the state, being surpassed only by its neighbor the Kennedy, which is also closed. Mining and shipment of copper ore from the Newton mine near lone ended with the expiration in mid-year of the bonus paid by the United States Government. Clay production continued at a good rate. A new plant was completed by De Angelis Coal Company at the Buena Vista lignite mine, and experimental work started late in 1947 on the produc- tion of montan wax, mineral pigments, and briquettes from lignite mined at that property and another deposit near lone. C.A.L. Talle 8. Mineral production fron I Amador County during 19 Jil Product Quantity Value 198,264 short tons 1,674,000 pounds 4,724 troy ounces 11,598 troy ounces $380,496 351,540 Gold. . - - -- 165,340 Silver - -- - 10,496 5,317 913,189 BUTTE COUNTY Geologic Features. Butte County lies at the junction of three major California geomorphic provinces. The southern terminus of the volcanic Cascade Range is near the northern border of the county ; the western half of the county is part of the Great Valley ; and the eastern half is within the northern Sierra Nevada. The rocks of Butte County may be divided roughly into two major groups and eight sub-groups. The sub- jacent or bedrock series consists largely of metasediments and meta- volcanics of pre-Cretaceous age, and serpentine and granitic rocks intru- sive into them. The Superjacent or overlying series consists of Pleistocene and Recent alluvium, late Tertiary volcanics (chiefly basalt and ande- site), early Tertiary sediment, and Upper Cretaceous sediments. Rocks of the Superjacent series lie unconformably upon the folded bedrock surface. The Great Valley in Butte County presents, for the most part, exposures of Pleistocene and Recent alluvium, but narrow outcroppings of the underlying Cretaceous and Eocene sediments are exposed along major water courses at the eastern edge of the valley where they lap up onto the tilted bedrock surface of the main mass of the Sierra. In the Sierran foothills, the bedrock metavolcanic greenstones and the metasediments trend roughly northwest, the structure being dis- rupted in many places by large intrusions of serpentine and still larger ones of granitic rocks. An excellent section of basement rocks is exposed along the North Fork of the Feather River. Leaving Oroville, Highway 24 passes successively through a broad belt of metavolcanic greenstones, Calaveras ( ?) slate, a small body of serpentine, more greenstone, a large body of serpentine, and finally into granodiorite. Small limestone lenses appear in the metasediments at some points. Andesites and basalts of the Cascade province cover the bedrock in the extreme northeastern part of Butte County and rhyolite tuff of the 36 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 Pliocene Tuscan formation underlies the volcanics at some points. The Tuscan formation interdigitates with the sediments of the Tehama forma- tion under the Great Valley. Strike faulting largely of thrust type disrupts the bedrock structures in some parts of the county, but to date no great system such as is knoAvn in the Mother Lode region has been described in the northern Sierra Nevada. Normal faults that cut the Tertiarj' and Quaternarj- volcanics have been described. Mineral Resources. The principal mineral resources of Butte County are gold, miscellaneous stone, and crystalline limestone. The first two were mined in considerable quantity during the year. Limestone reserves although large and of a quality suitable for processed lime and Portland cement were not exploited during 1947. Substantial quantities of lead, zinc, copper, chromium, and cadmium were mined during war- time but properties which produced these metals are now idle for the most part. Small quantities of platinum and silver were recovered during 1947 operations. Other minor resources of the county which were not exploited are brick clay, talc, mineral water, mineral paint, lignite coal, and man- ganese. A few diamonds of good quality have been taken from placers in Butte County over a long period of years. Mining Activities During 1947. The most productive single opera- tion in Butte County in the mineral industry during 1947 was the Lancha Plana No. 5 gold dredge on Butte Creek. This connected-bucket dredge had 65 electrically powered buckets of 4^ cubic-foot capacity. Such dredges are capable of digging 80 to 100 feet below the water line. Other large dredging operations were Yuba Consolidated Goldfields Butte Unit dredges; the Gold Hill Dredging Company's Kister dredge; Placer Exploration Company's Drescher Ranch dragline; Vasco Mining Com- pany's Big Hill dredge ; and Hoosier Gulch Placer's Boat No. 1 dragline. All of these worked in the Oro-\411e district. Several drift mines produced substantial quantities of gold-bearing gravels during 1947. The largest of these was the Morris Ravine or Split Rock mine in ]\Iorris Ravine, 3 miles northeast of Oroville. This operation was unique in that a ditch-digging machine was used to recover gravel from a timnel large enough to admit the entire bulky apparatus. Other drift mines operated during 1947 were the Shawnee in the Butte Creek district and the Dally in the Magalia district. The Surcease mine, a lode property 7 miles northwest of Yankee Hill, was operated by the Hoefling Brothers until April 1947, but since has closed down. Other lode mines reporting production for 1947 were the Wyoming in the ]\Iagalia district and the jMonte at Understock. The two largest producers of rock products in Butte County were the Henry J. Kaiser Rock Products Company on the main highway between Marysville and Oroville, and the Butte Creek Rock Company located on the Centerville road east of Chico. The latter has greatly increased its crushing plant in the last 2 years from a former capacity of 1,000 tons per day. Both the plants utilize the enormous piles of rock left by the gold dredges. Several hundred tons of high-grade chrome ore were produced from the Lambert mine in ]\Iagalia district by Helmke, Thomas, and Janssen. O.E.B. MINERAL RESOURCES AND PRODUCTION Tahlc 9. Mineral production from Butte County during 1947 37 Product Quantity Value 308 short tons 27,037 troy ounces 55,643 short tons 2,201 troy ounces I Gold . -.- $946,295 57,123 Silver- - 1,992 Unapportioned (chromite, natural gas, crude platinum 306,000 $1,311,410 1 Value included with "Unapportioned." CALAVERAS COUNTY Geologic Features. Calaveras County is situated principally in the Sierra Nevada, although the extreme northwestern portion lies close to the Great Valley. The county extends across the Sierra almost at right angles to the structural trend. Hence the structural and stratigraphic sequence in Calaveras County is a fair cross-section of the central Sierra Nevada as a whole. The geologic formations of the central Sierra have been conveniently divided into two major groups known as the subjacent or Bedrock series and the Superjacent or overljdng series. The Super- jacent series lies unconformably upon the Bedrock series and shows far less severe folding and metamorphism than does the Bedrock series. The county can be divided into three areas on the basis of the bed- rock lithology. The northeast quarter is made up mainly of granitic rocks of Upper Jurassic age with erosional remnants of Tertiary vol- canics resting on them. The central half of the county consists princi- pally of complexly folded and faulted metamorphic rocks of the Cala- veras formation. Slate, schist, phyllite, quartzite, argillite, crystalline limestone, and greenstone members make up the Calaveras. Granitic rocks of great extent invade the formation in many places, and less extensive intrusions of ultrabasic rocks such as peridotite (serpentin- ized) and pyroxenite are common. The general structural trend of the folded bedrock is northwest but the central part of the county lacks the belted arrangement of the rocks of the western quarter. West of the Mother Lode, rocks of the Calaveras and Amador groups outcrop in alternating bands owing to tight isoclinal folding accompanied by fault- ing. The Mother Lode itself is a major structural feature of such magni- tude that thousands of feet of strata are cut out by the faulting at various places along its 120-mile length. The sj^stem passes through Calaveras County in a northwesterly direction from Carson Hill on the Stanislaus River to Middle Bar on the Mokelumne River. Another mineralized zone controlled largely by thrust faults more or less parallels the Mother Lode 8 or 10 miles to the west of it. Copper- opolis, Campo Seco, and several other copper camps comprise the foothill copper belt of the Sierras, a mineral province almost as well kno'wn as the Mother Lode, though not nearly so productive. Substantial amounts of copper were produced along the belt during both world wars but copper mining is now at a low ebb. In the Superjacent series of Calaveras County, the early Tertiary gravel channels at the base of the series have been of major economic 38 COUNTIES OF CALIFORNIA 1 947 [BuU. 142 importance. They formed during the erosion of the upper parts of the gold lodes and consequently contain concentrations of placer gold. Later, rapid bnrial by mid-Tertiary pyroclastics and late Tertiary flow lavas preserved parts of the old river channels from the erosion that followed. However, unexposed parts must now be exploited by tunneling under the volcanic cap-rocks. The old river systems somewhat resembled the present stream systems in general distribution, but the mountain relief was far less than exists today. The climate was subtropical, and chemical weathering was very pronounced. This type of weathering was respon- sible for the large-scale decay of the gold lodes and for the formation of valuable deposits of quartz sand and clay. Mineral Resources. Gold lodes and auriferous placers still form the principal mineral wealth of Calaveras County. Because of current labor conditions and high operation costs, however, only a few of the many deposits are now being exploited. Most of the recent mining activity has been in the West Point, Angels Camp, and Copperopolis districts. Copper reserves are in much the same status as gold. Large tonnages of low-grade sulfide copper ores still remain in the foothill copper belt. Heaw production of zinc and lead from the Campo Seco district was reported through the war years but zinc production virtually ceased there in July 1947 when the Penn mine closed do-^Ti. Substantial reserves of zinc-lead-copper ore still remain in the Campo Seco district. Millions of tons of limestone suitable for portland cement and processed lime occur within the county boundaries. Calaveras County already has one of the largest portland cement plants of the state. Numerous deposits of limestone, which might be developed, are idle. A high-iron clay suitable for ceramic shapes such as terra cotta pipe is mined in the vicinity of Valley Springs. Reserves in that part of the county are large. The clay is a high-strength type and is mixed with other clays to make ceramic batches that meet certain specifications. Clay shale is also mined in the Valley Springs district for similar purposes. Several of the ancient channel-gravel deposits contain quartz crystals suitable for use in electronic devices. Several hundred pounds were mined for that purpose near Mokelumne Hill during the late war. Some crystals weighed more than 100 pounds. The deposits are by no means exhausted. Channel gravels are also an almost unlimited source of stone that can be processed into aggregate and road metal. Small deposits of talc occur along the Mother Lode as hydrothermally altered parts of serpentine bodies. This material was once extensively mined and dressed for building facings. Another material wideh^ used as building blocks, dressed stone, etc., is the indurated rhyolite tuff of the Valley Springs formation. This material is also suitable for crush- ing to aggregate or road metal. Minor mineral resources of Calaveras County include mineral water, lead, and silver. Silver is produced largely as a by-product in the refining of gold, with which considerable silver is alloyed. Mining Activities During 1947. The largest single operation in the county during 1947 was Calaveras Cement Company's portland cement plant at Kentucky House near San Andreas. Recent improvements and additions to the plant have increased its capacity to 7,500 barrels per day. New equipment includes two 87 Marcy mills and two 8 by 22 bob- tailed rake-classifiers in the raw-grinding department; three 48-inch MINERAL RESOURCES AND PRODUCTION 39 Telsmitli cone crushers for secondary grinding ; a new 10-ton crane for handling rock in raw storage; two 86 Marcy mills for finish grinding; and an increased truck fleet for hauling rock and cement. The increased plant capacity required new assurances of sufficient long-time limestone reserves so an extensive diamond-drilling program was undertaken at No. 4 quarry. The program required 10 months to complete and more than 6,000 feet of holes were drilled. Sufficient high- grade limestone was developed to furnish raw material for full-capacity production for a long period of time. In addition, the drill cores outlined lenses of schists of different compositions which are particularly adapt- able to the manufacture of the special cements now demanded by the market. The road to No. 4 quarry has been widened and improved to handle the increased traffic. Activities planned but not yet completed include the installation of a Cottrell precipitator to control dust in stack gases, and enlargement of the capacity of the company reservoir to assure an adequate water supply during the driest seasons. Calaveras Cement Company employs about 275 men at the plant. The principal producing gold mines in Calaveras County were the Mountain King mine northwest of Copperopolis, the Centennial mine at "West Point, the Penn mine at Campo Seco, and the Cuneo property on San Antonio Creek. Small intermittent production, both lode and placer, was reported from widely scattered points such as Linden, Camanche, Angels Camp, Altaville, Natoma, Waupt Creek, Kailroad Flat, Glencoe, and ]\Iurphys. At Campo Seco, the Shawmut Copper Mining Company operated the Penn mine until July and produced considerable gold and some silver as by-products in the recovery of zinc, lead, and copper. The ore was processed at the Eagle Shawmut mill, and gold- and silver-bearing pyrite concentrate was shipped. Lead was also a by-product of the ores in which the dominant metals are zinc and copper. Mining was carried on from the No. 2 and No. 3 shafts ; most of the ore came from above the 1,400 foot level. The operators were H. C. Mueller and George W. Clemson of Chinese Camp ; D. C. Peacock superintended the operation. The Mountain King Mill and Mine Company of Fresno operated the Mountain King mine through 1947. This mine was one of the three largest producers in the county. The vein is at the contact of ]\Iariposa slate and Logtown Ridge greenstone; it trends N. 32° W. and dips 25° to 30° NE. Considerable quantities of ore were found in hj^drothermally altered greenstone adjoining the vein. The Centennial mine at West Point (formerly the New Champion) was operated throughout most of the year under the management of M. G. O'Hanlon and Son. It is one of the few gold mines which has been operated continuously over a period of several years. Development is progressing through a 200-foot inclined shaft and drifts along the strike of the vein. The ore body strikes N. 8° to 10° W. ; and dips about 60° "W. and pitches south at a low angle. It has been exposed for a distance of 175 feet along the strike. The ore shoot is composed of pyrite, galena, and free gold in a quartz gangue. Both wall rocks are grano- diorite. Average gold recovery has been in excess of $50.00 per ton, which is more than 90 percent. The mill and hoisting equipment have 40 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 been completely overhauled and considerable new equipment has been added. The California Pottery Company continued to produce high- strength, high-iron clay at its quarries near Valley Springs. The clay is shipped to the company plant at Niles, California, where it is added to ceramic batches for sewerpipe and other fired clay products. Brownlite Products continued to produce volcanic ash for use as lightweight aggregate from quarries near Valley Springs. O.E.B. Tahle 10. Mineral production from Calaveras County during 19^1 Product Quantity Value 1,242,000 pounds 5,171 troy ounces 90 short tons 97,076 troy ounces 2,350 short tons $260,820 Gold 180,985 25,920 Silver - - _- -- -- 87,854 568,700 Unapportioned (cement, raw clay, pumice, sand and 3,075,042 $4,199,321 COLUSA COUNTY General Geologic Features. The general topographic and geologic features of Colusa County present a striking belted arrangement along north-south lines. The eastern half of the county is in the flat-floored valley of the Sacramento River while the western half includes a series of parallel ridges of the Coast Ranges trending N. 10° -20° "W. The suc- cession of sharp narrow ridges and parallel narrow valleys has resulted in development of a perfect trellis drainage pattern with the major consequent streams running eastward to the Sacramento River and their subsequent tributaries carving north-south valleys at right angles to those of the major streams. Structurally, the county is essentially the west limb of a syncline whose north-trending axis is not far from the Sacramento River. This structure has existed at least since early Pliocene time. A geologic section westward across the county would show then, first, the deep flat-lying Quaternary alluvium of the Sacramento Valley, a series of gently east- ward-dipping discontinuous caps and terraces of Pleistocene gravels of the Red Bluif formation, then the underlying poorly sorted sandy silt- stone beds of the upper Pliocene Tehama formation dipping 5° to 8° E., underlain in succession farther west by thick steeply dipping sandstones and shales of the Upper Cretaceous Chico formation, the Lower Creta- ceous siltstones and shales (Horsetown), Upper Jurassic Knoxville and Franciscan formations, and finally along the western border of the county, a series of schists of possible Franciscan ( ?) and pre-Franciscan age. Two important structures interrupt the succession of eastward- dipping formations : The Rumsey anticline, extending southward from "Williams in Colusa County over 30 miles to Capay in Yolo County, and the Sites anticline, 35 miles long, trending northward through the town of Sites in north-central Colusa County into central Glenn County. The Rumsey anticline is the principal structure of the low Rumsey Hills and MINERAL RESOURCES AND PRODUCTION 41 involyes steeplj- folded Upper Cretaceous beds, faulted along the west limb, and surrounded hj Eocene and upper Pliocene sedimentary strata ; only tbe northern end of the anticline extends into Colusa County. The Sites anticline is an extremely narrow elongated isoclinal fold with ver- tically dipping Lower Cretaceous Horsetown beds exposed at the crest. The Horsetown beds, probably 5,000 feet thick, are flanked by 9,700 feet of Upper Cretaceous Chico sandstones and shales which lie unconformably on the Horsetown greenish siltstone and shale. The anticline is compli- cated by northeast-striking oblique faults with chiefly horizontal dis- placement. The s^-ncline to the west is a broad gentle fold. Tertiar}' formations of Colusa County were discussed by Anderson and Russell ^^ with an accompanj-ing reconnaissance geologic map of the area. Geologic reports and maps by Kirby ^^ cover the Rumsey and Sites anticlines. Mineral Resources. A small amount of chromite was mined from lenses in serpentine in 1918. Gold has been mined from shallow deposits in sandstone and shale near the contact of Franciscan shales with intru- sive serpentine near Wilbur Springs. Hot saline and sulphur springs and cool carbonate springs occur in the western part of the county near the contact of Cretaceous sediments with Franciscan metamorphic rocks, and the ultrabasie rocks that intrude the latter. Seepages of oil occur in the Wilbur Springs district in the Knox- ville shales near the contact with Franciscan chert and serpentine ; in Knoxville sandstone beds along the axis of an anticline near Mountain House ; and along the bottom of Sand Creek where it cuts through a small fold in the Chico beds west of Arbuckle. Gas seepages on the Rumsey Hills anticline in southern Colusa County and along the crest of the Sites anticline in the north central part of the county led to the drilling of a number of wells, beginning in 1900 in the Rumsey area and 1925 in the Sites area. All were abandoned as uon-commerical, although showings of gas and salt water were usually encountered. Cinnabar occurs in seams in serpentine and in the altered shales, sandstones, and conglomerates near serpentine contacts. It is associated with seams and ledges of silica carbonate rocks. Massive sandstone, of Upper Cretaceous age, was quarried for many years from an area just east of Sites in upper Stone Corral Creek in the north central part of the county. The rock is a compact blue-gray sand- stone, weathering buff to gray, in beds from 18 inches to 18 feet thick, which crop out for 20 miles from the northern to the southern part of the county, striking approximately N. 20° W. and dipping about 40° E. under the younger Tehama gravels and alluvium of the Sacramento Valley. The quarry was most active from its opening in 1891 to 1913. It is of especial interest as it supplied ' ' Colusa sandstone ' ' ^^ for many well- known buildings in San Francisco, Sacramento, San Jose, Monterey, and Hawaii. Among such are the Ferry building, Flood building, Merchants National Bank, and St. Francis Hotel in San Francisco. The excellence of the stone as a building material is illustrated by the fact that the Ferry " Anderson, Charles A., and Russell, R. Dana, Tertiary formations of northern Sacramento Vallej', California : California Jour. Mines and Geology, vol. 35, pp. 219- 2.53, 1939. 1= Kirby, J. M., Rumsey Hills area: California Div. Mines, Bull. IIS, pp- 601-605, 1943, and Kirbv, J. M., Sites region: California Div. Mines, Bull. 118, pp. 606-608, 1943. 1" Colusa County: California Min. Bur. Bull. 3S, pp. 118-125, 1906, and Rept XIV, pp. 191-195, 1915. 42 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 building, built in 1896 and first to use Colusa stone, shows only minor spalliug and other weathering effects in 1948. Sand and gravel deposits are mined on the banks and bars of the Sacramento KiA'er and tributary creeks. Salt has been produced by evaporating water from saline springs in Antelope Valley near Sites. Sulphur occurs in the quicksilver deposits at Sulphur Creek. The mines and mineral resources of Colusa County have been described by Logan.^'^ Significant Activities During 1947. The mineral production of Colusa Count}^ for 1947 consisted of gold, silver, sand and gravel. The latter was mined from four pits on the west bank of the Sacramento River between Colusa and Princeton. The material was used on roads and as an aggregate for concrete. J.C.O. Table 11. Mineral production from Colusa County during 19^1 Product Quantity Value Gold --- 6 troy ounces $210 225,729 short tons 89,750 Silver 3 troy ounces 3 $89,963 CONTRA COSTA COUNTY General Geologic Features. Contra Costa County embraces 734 square miles of land area on the southern shores of San Pablo Baj", Carquinez Straits, Suisun Bay, and the San Joaquin Eiver. The most prominent topographic and structural feature is ]\Iount Diablo situated approximately in the geographical center of the county. It is one of the highest peaks in the central Coast Eanges, rising to an elevation of 3849 feet, and has been selected as the initial point in the survey of the Gen- eral Land Office controlling most of central and northern California. Mount Diablo, according to Taff/^ is an oval-shaped mass of igneous, sedimentary and metamorphic rocks of the Franciscan (Jurassic) for- mation covering about 15 square miles, protruding through the center of an anticlinal fold 50 miles long. The trend of the fold is northwest- ward and its flanks are composed of Cretaceous and Tertiary rocks which make parallel ridges of erosion about 2,000 feet high on the northeast and southwest sides of the mountain. Both Lower and Upper Cretaceous rocks are exposed and the Tertiary section consists of lower Eocene to Pliocene rocks. Quaternarj^ alluvium covers the Tertiary and Cretaceous rocks in Ygnacio Valley northwest of Mount Diablo and in the eastern part of the county along the delta of the San Joaquin River. The geologic structure of the Mount Diablo area consists of two elements : first, the anticlinal fold, developed at the close of the Tertiary period, which traverses the county in a northwestward direction and extends beyond its borders in both directions ; and second, the upthrust !■ Logan, Clarence A., Colusa County : California Div. Mines Rept. 25, pp. 284- 300 1929. i«Taff, J. A., Geology of ML Diablo and vicinity: Geol. Soc. America Bull., vol. 46, pp. 1079-1100, 1935. MINERAL RESOURCES AND PRODUCTION 43 of the core of Franciscan rocks, as a fault plug, through the overlying Upper Jurassic and Cretaceous strata in the center of the anticline. The upthrust occurred after the close of the Tertiary period. The foothills on the southwest flank of the mountain are covered by continental sediments and interbedded volcanics of Pliocene age which form a syncline, over- turned to the southwest. These foothills descend on the west into the narrow trough of the northwest-trending San Ramon Valley. Drainage here is northwestward and the west side of the valley is the locus of the Sunol-Southampton (Calaveras) thrust fault. North of the town of Wal- nut Creek the Southampton fault cuts into the northwest limb of the Mount Diablo anticline. A series of northwest-trending ridges marks the uplifted block west of the Southampton fault. The strata exposed range in age from Pliocene to Jurassic. Structurally they represent a series of anticlines and syn- clines locally faulted and overturned at numerous points. Eventually they merge westward with the tidal marsh of the bay. Mineral Resources. The mineral resources of Contra Costa County are particularly important because they are close to the industrial cen- ters surrounding San Francisco Bay. The important commercial min- erals are : clay and shale for brick-making, limestone, mineral water, natural gas, pumice, quicksilver, sand, silica (molding and glass sand), and miscellaneous stone (crushed rock) . Clay and shales at Richmond and Port Costa provide raw material for making common red brick. The pro- duction of sub-bituminous coal began in 1861 from Eocene beds on the northeast flanks of Mount Diablo. About 3,000,000 tons, valued at $15,- 000,000 had been produced by 1902 when mining ceased entirely. Con- spicuous outcrops of Recent limestone (travertine), used in cement making , are found along Lime Ridge about 5 miles southeast of Concord. The cement plant is located at Cowell. Mineral water from this county has been produced commercially for many years. The county also sup- plies molding (silica) sand for the local steel industry centered around Pittsburg. The southeast end of the Rio Vista gas field extends into Contra Costa County and seven wells operated by the Standard Oil Company produce gas from Eocene sands at a depth of about 4,500 feet. Pumice in the form of a pumiceous tuff is found in the Pliocene volcanics extending northwestward from Mount Diablo. Quicksilver, chiefly as metacinnabarite, is produced from ore bodies along the Franciscan ser- pentine-sandstone contact on the east side of Mount Diablo. Deposits of fine dune sand of Quaternary age on the south shore of the San Joaquin River are mined in the vicinity of Antioch. Miscellaneous stone (crushed rock) is obtained from metamorphosed Franciscan sandstone and chert at numerous points throughout Contral Costa County. Small amounts of asphalt, copper, diatomite, gold, lead, and silver, have been produced. ^^ Significant Activities During 1947. Brick-making and the manu- facture of clay products, dinner-ware, and sanitary-ware, are important elements of the mineral industry in Contra Costa Count3^ Local clay and shale are used by two brick companies in the manufacture of common red brick and hollow building blocks. Three additional plants purchase high-grade clays from Placer and Amador Counties which they use in making fire-brick, sanitary-ware, and clay products. A dinner-ware plant " Laizure, C. McK, San Francisco field division — Contra Costa County : California Div. Mines Rept 23, pp. 2-31, 1927. 44 COUNTIES OF CALIFORNIA — 1 947 [BuU. 142 purchases Tesla clay which it blends with crude clay from out-of-state deposits. Natural gas is produced from the southern end of the Rio Vista gas field which extends into Contra Costa County. The seven producing wells are controlled by the Standard Oil Company and gas is delivered to the Pacific Gas and Electric Company pipe line. It is possible that additional wells may be drilled in this area. Mineral water is produced commercially from springs located near Martinez at Alhambra Springs and Oak Springs. This water is bottled and distributed for consumption in the San Francisco Bay area. A small quantity of pumice is produced from a pumiceous tuff occur- ring in the foothills east of Pittsburg. The crude material is crushed, screened, and used as an aggregate in the manufacture of building blocks. Clay-free foundry sand is produced in small quantities from dipping beds of Eocene sandstone south of Antioch. The crude sand is washed, classified, and is used in preparing synthetic sands for iron foundries. A similar sand is also produced from Eocene beds in the workings of the old Nortonville coal mine near Clayton.-^ The sand is mined by drifts and overhand stopes. It is transported to a crushing and washing plant near Pittsburg where it is prepared for use in steel and iron foundries. The silica content of the end products from these two operations is 95 percent. The south shore of the San Joaquin River in the vicinity of Antioch is bordered with dunes of fine sand. A number of operators, using dragline- buckets, load this sand directly to railroad cars for shipment to asphalt plants. Large quantities of crushed rock are produced from indurated sand- stone at Blake Bros. Richmond quarry. Basalt is the source of crushed rock at the Upton quarrv of Henry J. Kaiser Companv. F.F.D. Table 12. Mineral production from Contra Costa County during 19J^1 Product Quantity Value Clay products, heavy clay (other than pottery and refractories) Sand and gravel Stone. 378,734 short tons- 472,020 short tons- Unapportioned (raw clay, natural gas, and pumice) . Total value S248,403 509,546 630,733 $1,388,682 1 U. S. Bureau of the Census not at liberty to publisli flguie. Value not included in county total. DEL NORTE COUNTY General Geologic Features. Del Norte County lies within the rugged and complex Klamath Mountains province. Intrusive rocks, chiefly serpentine and peridotite, cover most of its area except for a belt of Franciscan sandstone and shales 5 to 10 miles wide along the coast, and the outcrops of diorite and granodiorite that make up the mountains along the border of Siskiyou County. Small areas of diorite and granodio- rite also occur in the serpentine belts, and there are remnants of meta- ^ow^right, L. A., California foundry sands: vol. 44, pp. 37-72, 1948. California Jour. Mines Xnd Geology, MINERAL RESOURCES AND PRODUCTION 45 morphic, sedimentary, and volcanic rocks wliieli have been intruded by both the granitic rocks and the peridotite. The geology of Del Norte County is shown on maps prepared by Maxson ^^ and published by the California State Division of Mines. Mineral Resources. Chromite occurs in lenses in serpentine. Copper minerals, chiefly chalcopyrite, are also found in veins and lenses in ser- pentine at or near the contact with granitic rocks. Pyrite and pyrrhotite are accessory minerals. Gold and platinum are found in the stream gravels and beach sands associated with magnetite and chromite. Gold also occurs in narrow quartz veins and stringers in greenstone and slate near the contact with diorite and granodiorite. Native quicksilver and cinnabar occur in vugs and fissures in serpentine and the rocks in contact with it. Sand and gravel are mined from the banks and bars of the Smith River, and heavy boulders for building the harbor jetties were quarried from the greenstone outcrops on Preston Island. The mines and mineral resources of Del Norte County have been described by Laizure -- and Maxson.^^ Significant Activities During 1947. The Tyson chrome mine at French Hill was converted into an open-pit operation in 1947. Water was brought from French Hill through 2j miles of ditches and delivered to a No. 3 giant under a 250-foot head. The physical characteristics of this deposit are favorable for a hj^draulic operation. The serpentine is soft and broken and a good slope provides plenty of dump room for tailing. Chromite occurs in irregular lenses and was difficult and expensive to mine by underground methods. Shults Brothers installed a 25-ton Lacy rotary furnace at the Webb (juicksilver mine during the year, and a new adit was driven to develop the deposit at a lower elevation. A bunk house and dining hall w^ere built to accommodate the crew. Rock was quarried at Preston Island and used to build the jetties at Crescent City harbor. Sand and gravel were mined from pits on the banks of Smith River and used for concrete agsTegate and on roads. J.C.O. Table 13. Mineral production from Del Norte County during 1947 Product Quantity [ 1 \'alue 640 short tons 55,017 short tons 1 1 $322,156 $322,156 1 Value included with "Unapportioned." EL DORADO COUNTY General Geologic Features. Northernmost of the Mother Lode counties. El Dorado County is bordered on the west by Sacramento and Placer Counties. It extends from the lower foothills on the west, up the ^ :Maxson, J. H., Economic geology of portions of Del Norte and Siskiyou Counties, northwesternmost California : California Div. Mines Rept. 29, pi. 4, 1933. 22 Laizure, C. McK., Del Norte County: California Min. Bur. Rept. 21, pp. 281-294, 1925. 23 Maxson, J. H., Economic geology of portions of Del Norte and Siskiyou Counties, northwesternmost California : California Div. Mines Rept. 29, pp. 123-160, 1933. 6—4932 46 COUNTIES OF CALIFORNIA 1 947 [BuU. 142 gradually rising slope of the Sierra Nevada to the summit of the range (8,000 to 10,000 feet) thence across Lake Valley to the Nevada state line. Part of Lake Tahoe is included within its limits. It occupies part "of the drainage basin of the Middle Fork of American River and the larger part of the area drained by Cosumnes River. The western region was, in Cretaceous time, part of an extensive peneplain occupied by Jurassic and Paleozoic formations; there are no marine deposits younger than the Mariposa (Upper Jurassic) clay slate. In El Dorado County, the western part of the bedrock complex con- sists largely of altered igneous rocks derived from basic tuff and other basic volcanic debris. Through dynamic metamorphism, the fragmentary material has been changed principally to chlorite or amphibolite schist. The principal Jurassic metasediments of economic importance are the Mariposa slate beds of the Mother Lode belt which cross the county from north to south by way of Georgetown, Placerville, and Nashville. In the southern part of the county this slate strikes north and is bordered on the west by the Logtown agglomerate, which has been placed as upper Middle to lower Upper Jurassic by Taliaferro.^^ Near Diamond Springs the slate strikes northeast, but north of Placerville it again strikes north- northwest. From Garden Valley northward, the slate is divided into two strands by a large wedge of amphibolite schist. The Mother Lode veins occur in both the slate and schist, as well as along the borders of narrow serpentinized dikes occasionally found in the slate. An important ancient river system, possibly in part as old as the Cretaceous, but mantled by middle Tertiary rhyolite and andesite, crossed the Mother Lode just south of Placerville. It was partly exposed by later erosion and yielded great quantities of gold to the pioneers. West of the Mother Lode the meta-igneous rocks as well as the Paleo- zoic metasediments were extensively invaded by gabbrodiorite and grano- diorite and by smaller bodies of ultrabasic rocks. The last named have since been serpentinized. Following profound erosion during the Cretaceous, the birth of the present Sierra Nevada began, accompanied by the rejuvenation of streams in the early Tertiary. Finally, outbursts of rhyolite ash followed by repeated and much more extensive eruptions of andesite came from the mountains to the east. The quantity of the andesite, which descended the slope in the form of mud and breccia, was sufficient to fill entire valle^^s. Large river canyons and their deposits were thus covered and protected until found by the pioneer gold miners. Modern stream systems established since the end of that volcanic era have stripped off a great deal of the volcanic cover and much of the older metasediments, and have exposed the underlying granitic rocks both east and west of the Mother Lode. Long sections of ancient stream channels were washed out and the gold they contained was again concentrated, this time in the modern streams. East of the Mother Lode and west of the summit of the Sierra Nevada, the remaining older rocks that only partially cover the granite are Paleozoic (Calaveras formation). The rocks of this Paleozoic com- plex include clay slate and phyllite, altered limestone and sandstone, quartz-mica schist and graphitic schist, chert, and a variety of altered -* Taliaferro, N. L., Manganese deposits of the Sierra Nevada — their genesis and metamorphism: California Div. Mines Bull. 125, p. 284, 1943. MINERAL RESOURCES AND PRODUCTION 47 volcanic rocks, now largely changed to schist. This is the East Belt of the gold miner. Due to pressure from the invading granodiorite, all of the older rocks, including the Mariposa and other Jurassic beds on the west, have been closely folded and rendered schistose ; the schistosity strikes north- west and dips steeply northeast. Long ridges with gentle westward slopes covered with andesite tuff and breccia extend into the higher mountains east of the Calaveras rocks. In these mountains also are many remnants of Pliocene moraines. Some roof pendants of clay slate and associated augite porphyrite on the eastern slope near Lake Tahoe have been called Juratrias. Two important faults have been mapped. One is the Mother Lode reverse fault system and the other is the great fault system along the eastern side of the Sierra Nevada, running nearly north through Lake Valley and Lake Tahoe. Mineral Resources. Until 1917, gold was the most important min- eral product of the county. In the period of rising wages and costs prior to 1930, gold production was small, but a sharp revival came with the depression of 1932, and from 1933 to 1943 the county yielded $15,000,000 in gold. The period of extremely high wages and prices since the end of the last war has been unfavorable for gold mining and recovery is only gradual. Prior to 1943, both lode mines and dragline dredges were pro- ductive. The dredging land has been quite thoroughly exploited; the acreage of this land was small. The remaining lode mining possibilities are numerous. Gold-bearing veins occur not only in the Jurassic clay slate and schists of the Mother Lode, but also in most of the rocks of the bedrock complex and around the borders of the invading granitic rocks, on both sides of that lode and as far east as Grizzly Flat at an elevation of about 4,000 feet. In this gold-bearing region, approximately 30 miles square, is a great variety of gold deposits ranging from base ore and low-grade auriferous sulfides through the free-milling, medium-grade, slate-quartz ores of the Mother Lode to the specimen gold of the seam diggings and the more complex but often good grade ores of the Paleozoic East Belt rocks. Large deposits of high-calcium limestone, mostly altered to dense, fine-grained marble, occur near Cool, in Marble Valley, near Rattlesnake Bar, and north of Dugans. These Paleozoic deposits have been closely compressed and tilted so that they appear as lenses standing on edge. Two such lenses have been worked to a vertical depth of 800 feet. Magne- sian limestone is also quarried east of Diamond Springs for making lime. More than 40 years ago, chrysotile asbestos was produced from serpentine areas near Georgetown and Greenwood. The county was one of the larger producers of chromite in 1915-18 and some production was made during the last war. Considerable disseminated ore remains which requires further experimental work in concentration before an economic product can be recovered. Copper has been mined in small amounts when price permitted, and one producer has been active recently. Some of mines and prospects are in amphibolite schist, but many are of contact- metamorphic type, at the borders of granitic rocks. These copper ores carry some gold and silver. Iron ore and scheelite have been mined in only small quantities. Lead and silver are by-products of gold-quartz ores, and small amounts of the platinum-group metals have been recovered 48 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 with placer gold. Some pyrite was shipped 30 years ago. Silica from veins in White Kock Canyon has been shipped for use in cleaning compounds. The black slate of the Mother Lode belt between Placerville and Kelsey is excellent for roofing granules and for sawing into slate shapes. From 1895 to 1912 substantial quantities of slate shingles were produced from several quarries there. At present the only use made of this slate is for roofing granules. Numerous soapstone quarries have been worked. Those most recently exploited are located near the railroad in the vicinity of Brandon and Latrobe. Deposits are also known near Shingle Springs, Placerville, and east of Diamond Springs. Sand and gravel are available for local use. White rhyolite ash deposits at Smiths Flat are so far undeveloped. Significant Activities During 1947. El Dorado County is one of the leading producers of high-calcium industrial limestone in the state. Two modern lime plants are located within its boundaries. At present, the value of these products exceeds half a million dollars annually, and the onlj- close competitor in either tonnage or value of output for this purpose is San Bernardino County. Several counties produce larger tonnages of limestone than El Dorado, but the bulk of it is mined for use in portland cement. California Rock and Gravel Company operated a large quarry near Cool where a nearly pure high-calcium limestone was produced for beet- sugar refining and other industrial uses. This company also supplied limestone during 1947 to the new plant of Auburn Lime Products Com- pany, 10 miles distant. The latter operated a rotary kiln for making several sizes of lime and also had equipment for crushing and screening limestone for poultry grits, glass, etc. This company's own limestone deposit, which produced stone for lime and other uses off and on since the sixties, is not being worked at present. At Diamond Springs, the large modern lime plant of Diamond Springs Lime Company utilizes magnesian limestone from its own quarry about 5 miles east of the plant to make lime for plaster, and also burns lime from the underground mine of El Dorado Limestone Com- pany. The latter company has been producing a very fine quality of white high-calcium limestone from workings that have reached a ver- tical depth of about 800 feet. They have a washing and hand-sorting plant to raise the grade of the limestone, which goes to steel mills (after being burnt to lime). This limestone is also sold for use in paint, sugar- refining, glass, etc. The limestone deposits of California, including those in El Dorado County have been described in detail in a recent report by Logan. The limestone industry in El Dorado County employs 150 or more men. Pacific Minerals Company, Limited, operates a crushing and screen- ing plant at Chili Bar on the South Fork of American River where the black Mariposa clay slate of the Mother Lode belt is made into roofing granules for use on ' ' ready roofing ' ' and shingles. The by-product dust and some crude slate are also marketed. Gold production in 1947 amounted to $104,790 which came from 13 small lode mines and 12 placers. More than $91,000 of this was from placers, principally^ small dredging operations. Shortage of water in the western part of the county hampered lode mining by the middle of summer, and caused some shutdowns. The Lilyama mine which has MINERAL RESOURCES AND PRODUCTION 49 copper- and gold-bearing ore, and the Shaw (Volo) mine were worked part of the year. The Grit mine at Spanish Dry Diggings was equipped with a mill and was prospected by Liddicoat Gold Mines Company. Soapstone is quarried by Pacific Minerals Company, Limited, from a deposit alongside the railroad at Shrub Spur, north of Brandon. C.A.L. , Table 1/^. Mmeral production from El Dorado Cotintij during 19Ji7 Product Quantity Value Copper 112,000 pounds 2,994 troy ounces 2 short tons 2,039 troy ounces 211,780 short tons 6 short tons $23,520 Gold Lead Silver Stone Zinc Unapportioned (lime, sand and gravel, slate, and soap- 104,790 576 1,845 483,991 1,452 1,024,846 Total value $1,641,020 FRESNO COUNTY General Geologic Features. Fresno County extends from the Coast Ranges across the San Joaquin Vallej^ to the crest of the Sierra Nevada. A rather complete series of Tertiary and Cretaceous sediments resting on the Franciscan is exposed in the southwestern part of the county. The same series is known to underlie the recent alluvium of the San Joaquin Valley because of extensive drilling for petroleum at such places as Coalinga and Kettleman Hills. To the east of the alluvium occupying the valley, which is about 50 miles wide, are exposures of the granitic core of the Sierra Nevada and older metamorphosed sediments. Mineral Resources. The outstanding mineral products of Fresno County are petroleum and natural gas, which are found at several Ter- tiary horizons, including the Eocene, at Coalinga and Kettleman Hills. Gravel, sand, and crushed rock are produced on a large scale by dragging the stream gravel, and crushing and screening the oversize. Brick and hollow tile are produced from local clay at Fresno. Chromite is associated with ultrabasic intrusive rocks in both the Sierra Nevada and the Coast Ranges. Manganese, as rhodonite or rhodochrosite, is associated with chert in these same localities. Most of the manganese occurrences are in the Sierra Nevada, but the only production has come from one deposit in the Franciscan of the Coast Ranges at the southwestern edge of the county. At the western, side of the county is a quicksilver district asso- ciated with Cretaceous sandstone. Tertiary volcanics which occur nearby suggest a possible origin for this mineralization. Tungsten is found in the Sierra Nevada associated with contacts of the granite with the meta- sediments. Brown garnets containing lime often accompany the scheelite. Granite is quarried from the extensive deposits of the Sierra for cutting into monuments. Minor amounts of placer gold are produced from the deposits mined primarily for gravel, sand, and cruslied rock ; also from deposits of fine gravel and sand by means of suction dredges. Deposits of diatomite and gypsum are known to occur in the county, but they have not been extensively developed. Deposits of limestone occur in the 50 COUNTIES OF CALIFORNIA — 1 947 [BuU. 142 metasediments near Dunlap and Tollhouse about 40 miles by road east of Fresno. Significant Activities During 1947. Production of petroleum and new drilling continued at fields near Coalinga, and a number of new producing wells were completed in this area. A new discovery of petro- leum in the Eocene was made at a point 3 miles southeast of the town of San Joaquin. Production of marl containing a high percentage of lime has been started recently from a deposit about 25 miles west of Fresno. Production of sand, gravel, and crushed rock continues at a high level. C.V.A. Table 15. Mineral prodtiction from Fresno County during 19-^7 Product Quantity Value Clay products, heavy clay (other than pottery and refractories) Gold Natural gas Natural gasoline and allied products: Natural gasoline Liquefied petroleum gases Petroleum Sand and gravel Silver 235 troy ounces- 63,814,000 M. cu. ft.... Stone Unapportioned (raw clay, crude feldspar, crude gyp- sum, mercury, pumice, and tungsten concentrates). 75,836,000 gallons 41.690,000 gallons 44,133,000 barrels 1,031,322 short tons.. 37 troy ounces - 164,910 short tons.. S8,225 6,750,000 3,948,000 1,699,000 75,388,000 1,141,346 33 292,835 114,872 Total value. $89,342,311 1 U. S. Bureau of the Census not at liberty to publish figure. Value not Included in county total. GLENN COUNTY General Geologic Features. The eastern third of Glenn County is within the Sacramento Valley and is covered with Quaternary silt, sand, and gravel. The western portion is within the foothills of the northern Coast Ranges and includes north- and south-trending belts of Jurassic and Cretaceous conglomerate, sandstone, and shale. In the north central portion of the county, patches of Cretaceous shale and Pliocene basalt outcrop in an area of Pliocene nonmarine sediments 3 to 10 miles wide, that extends about 18 miles south from the border. The general geologic features of Glenn County, lying directly north of Colusa County and in a similar position, are very much like those of Colusa County, previously described. The Anderson and Russell ^^ report also covers a portion of Glenn Count5^ Mineral Resources. Chromite occurs banded and disseminated in the narrow belt of serpentine that trends northwestward along the eastern slope of the northern Coast Ranges. Copper prospects occur in several places in western Glenn County. Float containing native copper was found in an adit driven in serpentine about 2 miles north of Chrome. Narrow stringers bearing gold, silver, and copper occur in the Fran- ciscan formation northwest of Elk Creek. Manganese oxides and silicates occur in chert beds in the Franciscan formation in ten localities in Glenn County. Natural gas occurs in Cretaceous beds at a depth of 2,240, feet about 7 miles northeast of Willows. There are extensive deposits *« Op. clL MINERAL RESOURCES AND PRODUCTION 51 of sand and gravel in many areas in tlie Sacramento Valle3\ The mines and mineral resources of Glenn County have been described by Averill.^^ Significant Activities During 19 i7. Mineral production for 1947 consisted of sand and gravel mined from creek beds. Madsen and Cramer operated a pit on the North Fork of Willow Creek, and the Orland Sand and Gravel Company operated a pit on Stony Creek north of Orland. The material was used for roads, stock corrals, and for concrete aggregate. A small quantity of natural gas was also produced. J.C.O. HUMBOLDT COUNTY General Geologic Features. The northern Coast Eanges trend in a northwesterly direction through Humboldt County, and contact a belt of pre-Cambrian metamorphic rocks of the Klamath Mountain province on a line extending southeastward through the countj^ from a point about 5 miles south of Orick to the middle of the eastern border. Franciscan sediments, mostly shale, argillaceous sandstone, and chert, cover the largest area included in the northern Coast Ranges within the county. They have been strongly folded and faulted and the strata dip at steep angles. A belt of Quaternary and Pliocene sediments 6 to 15 miles wide outcrops along the coast line for some 16 miles north and 20 miles south of Eureka, and extends inland along the Eel and Mad River valleys for some 30 miles. A considerable thickness of dark organic shales of Cretaceous age is in contact with the Franciscan formation in the areas west of Briceland and Bridgeville. The northeastern portion of the county, within the Klamath Mountain province, includes a wide belt of pre-Cambrian metamorphic rocks trending northwestward and flanked by Franciscan and Pliocene sediments near the coast. Belts of Jurassic granitic rocks, metamorphic rocks, and serpentine, are cut by the Klamath River as it flows southwestward through the northeast cor- ner of the county. The geology of Humboldt County is shown on maps prepared by Smith .-^ Mineral Resources. Chromite occurs in lenses in serpentine that outcrops in the northeastern portion of the county. Clay suitable for the manufacture of brick and hollow tile occurs in the Quaternary sedi- ments along the coastal plain. Lignite has been found in sandstone and clay beds in Eureka and in several localities along the Eel River and its tributaries. Native copper, bornite, chalcocite, and chalcopyrite are found in serpentine cut by gabbro dikes on Horse Mountain. Chalco- pyrite and sphalerite, associated with pyrite and carrying gold and silver, occur in veins between shale and schist on the Hoopa Reservation. Placer gold with silver and platinum is found in the beach sands, stream, and terrace gravels of the Klamath and Trinity Rivers. Limestone deposits occur in the Franciscan and Pliocene formations in several localities. Manganese minerals, oxides, carbonates, and silicates, are found in beds and lenses associated with chert in the Franciscan for- mation. Natural gas and oil showings occur in the sedimentary rocks in the southwestern part of the county. Commercial natural-gas wells have 2«Averill, Charles V., Glenn County: California Div. Mines Rept. 25, pp. 418-426, 1929. 27 Op.cit. 52 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 been developed in the Pliocene sands at 3,800 to 5,000 foot depths about 2| miles east of Fernbridge. Sand, gravel, and crushed rock are produced from the banks and bars of the Eel and ]\lad Rivers. The mines and mineral deposits of Humboldt County have been described by Averill.-^ Significant Activities During 1947. Hydraulic mines operated on bench gravels and old river channels along the Klamath River above Orleans. The Copper Bluff Mining Company was formed and resumed the development of the i)yritic zinc-copper deposit on the Hoopa Indian Reservation. Sand and gravel were mined from pits on the banks of the Mad River and used for roads and concrete aggregate. Brick and pottery clay and natural gas also contributed to the mineral production of Hum- boldt County during 1947. J. C. 0. Tahle 10. Mineral production from Huniholdt County during 19Jp Product Quantity Value Clay products, hea\^ clay (other than pottery and refractories . . s Gold 139 troy ounces 261,063 short tons 22 troy ounces 60,120 short tons S4 865 Sand and gravel ..__._ .__.. . __ 221,278 Silver _ _ _ . 20 Stone . 1 Unapportioned (raw clay, natural gas. and stone) - 90,201 Total value, .. __ ._ _, $316,364 1 Value included Tith "Unapportioned. " - U. S. Bureau of the Census not at liberty to pubUsh figure. Value not included in county total. IMPERIAL COUNTY General Geologic Features. Imperal County, with an area of 4.089 square miles, is dominated by the Salton Sea basin and is mostly within the Colorado Desert geomorphic province. The Chocolate, Palo Verde, and Cargo ]\Iuehacho Mountains, lying between the Salton basin and the Colorado River, are a part of the Mojave Desert province. The Laguna and Vallecito Mountains of the Peninsular Ranges province extend into the southwestern corner of the count}'. The Salton basin, a continuation of the trough of the Gulf of Cali- fornia, is separated from that by a very large delta of the Colorado River. This trough is a sunken fault block between active branches of the San Andreas fault. Ancient beaches and water lines show that this basin was once occupied by an extinct lake (Cahuilla). During the years 1905-07 it was again filled, by flooding of the Colorado River, to form the present Salton Sea. Sedimentation probably began in this basin in late Tertiary time -^ and was partially marine and partially terrestrial, as indicated by fossils and by gypsum and strontianite deposits around Fish and Carrizo Mountains. Quaternary sedimentation was mostly terrestrial, but some took place in Lake Cahuilla. The wind-deposited sand hills east of Imperial Valley constitute one of the largest belts of dunes in the United States and form a range of low hills 40 miles long and 2 to 6 miles wide. The Palo Verde Moun- tains in the northeast corner of the county are made up mainly of Ter- ^ Averill, Charles V., Humboldt County: California Div. Mines RepL 37, pp. 499- 52S, 1941. -•• Brown, J. S., The Salton Sea region, California : U. S. Geol. Survey Water-Supply Paper 497, 1923. MINERAL RESOURCES AND PRODUCTION 53 tiary voleanics. The Chocolate Mountains, forming the northeastern wall of the Salton basin, are composed partly of pre-Cambrian and pre- Cretaceous metamorphics intruded by Jurassic granitics, and partly of Tertiary audesitic and rhyolitic lava flows. The geology of the Cargo Muchacho Mountains to the south was described by Ilenshaw.^" In this range, pre-Mesozoic metamorphics have been intruded by a series of granitoid rocks, probably Mesozoic in age. There is also evidence that the Colorado River formerly flowed through the region. The Peninsular Ranges have a Jurassic acid-intrusive core which intruded existing sediments, some of which were Paleozoic, possibly Carboniferous. The Picacho Mountains on the southeast corner along the Colorado River basin are mainly voleanics underlain by pre-Mesozoic metamorphics. Mineral Resources. Imperial County has produced copper, gold, lead, manganese, and silver in addition to 21 different nonmetallic sub- stances. Of these the most important have been miscellaneous stone products, salt, gypsum, kyanite, strontium, brick, mica schist, and carbon- dioxide gas.^^ Production of copper has been from the concentrates produced at the American Girl mine in the Cargo Muchacho district. Mined for gold, the ore was concentrated, and this concentrate carried 3 to 5 percent copper. Oxidized copper mineralization occurs in the Picacho and Pay- master districts and on the west slope of Fish Mountain. Some sulphides have been noted in the monzouite of the Paymaster district of the Chocolate Mountains. Manganese has been produced mainly from the Paymaster district, but also occurs in the Palo Verde Mountains. Gold has been mined to some extent in every range, but the most productive area has been in the Cargo Muchacho and Picacho Mountains. Nearly 2^ million dollars in gold production has been reported since 1907, the latest in 1942. Lead-silver ores occur in the Picacho Mountains and the Pay- master district. In the Paymaster district the Paymaster mine has been the most productive. Prior to the formation of the present Salton Sea, salt was obtained from the saline crust on the old sea bed. Since the filling, it has been obtained by evaporation of the sea waters. Strontium ore (celestite) has been mined from a low hill on the north side of Fish Mountain. The celestite beds overlie gypsum beds in a sedimentary section and both are considered to be marine deposits, probably Tertiary in age. Kyanite has been mined from the Cargo Muchacho district, which has also pro- duced mica in the form of sericite schist. Both occur in the Vitrefrax formation "- which consists of metamorphics probably derived from sediments. The kyanite was difficult to separate from the quartz, and this problem has inhibited its use in recent years. Carbon-dioxide gas has been produced from the gas field southeast of the Salton Sea near Niland, first production having been in 1933. The most important nonmetallic mineral in Imperial County is gypsum, production going mainly into industrial uses. The deposit being mined is that of the United States Gj^psum Company north of Plaster City on Fish ]\Iountain. Other large deposits occur on Carrizo and Coyote Mountains. ™ Henshaw, P. C, Geology and mineral deposiit.s of the Carg:o Muchacho Mountains, Imperial County, California: California Div. Mines Kept. 38, pp. 147-106, 1942. •■'1 Sampson, R. J., and Tucker, W. B., Mineral resources of Imperial County: California Div. Mines Rept. 38, pp. 105-145, 1942. ^- Henshaw, P. C, op. cit. 54 COUNTIES OP CALIFORNIA — 1 947 [BuU. 142 Significant Activities During 1947. Cardox Western, Inc. con- tinued their operations in the Salton Sea carbon-dioxide gas field. Experi- mental work was carried on in the attempt to prolong the productive life of the wells, which, due to technical difficulties, averages only about 2 years. Several wells were drilled as part of a rather constant drilling program. The average well depth is about 635 feet. Most of the carbon- dioxide is marketed as dry ice and a small amount as liquid CO2. There are at least 50 different uses for carbon-dioxide in its marketed forms.^^ Operation of the kyanite quarry near Ogilby by the Vitrefrax Cor- poration was discontinued in 1946, but a small amount of kyanite was produced by the Western Non-Metallics Company of Ogilby in their mica- schist operation. The productive capacity of the operation is 500 tons of mica-schist per month. The ground mica is used mainly in roofing, foundry facings and as artificial "snow" for decorations. Keeping pace with building requirements, sand and gravel was produced as usual in the vicinitj' of El Centro and Brawlej^. The largest single mining operation in the county is that of the United States Gypsum Company operating on the northwestern edge of Fish Mountain, 26 miles northeast of Plaster City. The gypsum deposit is about 3 miles in length and 1 mile in width and is said to have the most uniform grade of any gypsum deposit in the United States, averaging 95 percent. •^■* Open-pit mining methods are used. The ore is loaded into side-dump cars and hauled over the company's o\^1^ railroad to the plant at Plaster City. This plant, operated originally by the Pacific Portland Cement Company?-, was enlarged, and a wallboard manufacturing unit was added during the year. The productive capacity on plasters was approximately doubled, and wallboard was produced late in 1947. R.M.S. Taile 17. Mineral production from Imperial County during 19Jil Product Quantity Value Sand and gravel Unapportioned (crude gypsum, scrap mica, and sand and gravel) - ._ _ . . 232,704 short tons 1 $907,843 $907,843 1 Value included with "rnapportioned." INYO COUNTY General Geologic Features. Inyo County, with an area of 10,224 square miles, is the second largest county in California and contains both the highest and lowest points in the United States. Mount Whitney, elevation 14,501 feet, is the highest, and Salt Flat in Death Valley is the lowest, at an elevation of 280 feet below sea level. The main divide of the Sierra Nevada is the west boundar}^ of the count3^ The major portion of the county is in the Basin Range geomorphic province. This province is an area of interior drainage, and the roughly parallel ranges alter- nating with basins and troughs are controlled by typical fault-block structure. 33 Bransford, J. C, Imperial carbon-dioxide gas field : California Div. Mines Rept. 38, pp. 198-201, 1942. 2* Sampson and Tucker, op. cit. MINERAL RESOURCES AND PRODUCTION 55 Owens Valley is a trough of tectonic origin whose floor has subsided along a series of parallel faults.^'^ It is partly filled by Tertiary and Quaternary sediments. The White-Inyo Range to the east is built up of a thick, complexly faulted and folded series of sedimentary rocks ranging in age from Triassic to Lower Cambrian, with volcanics of Triassic age. All of these have been intruded b}' igneous rocks, predominantly granitic in character.^^ Summit portions of some of the ranges, the Sierra Nevada, Coso, Argus, and Panamint, have areas of low relief which appear to be rem- nants of a single old-age erosion surface which extended across the entire region prior to the early or middle Pleistocene range-forming fault move- ments.^^ The latter three ranges are composed mostly of pre-Tertiary rocks, with a thickness of over 45,000 feet of pre-Cambrian metasediments and Paleozoic limestones, dolomites, shales, and quartzites. Intrusions, ranging from granite to gabbro, occurred during the Jurassic Nevadan orogeny. Death Valley, at least in the southern part, is thought to be a syncline modified by normal faulting rather than a graben.^^ This area contains rocks of all the great geologic time divisions, Archean through Quater- nary, with an aggregate thickness of 30,000 feet for the stratified rocks alone.^*^ Folding and faulting has been on a grand scale, and some features associated with large, middle or late Tertiary thrust faulting appear to be without counterpart in North America. The largest of these thrusts is the Amargosa thrust, found in the Tecopa area in the southeast portion of the county .^*^ Mineral Resources. Inyo County has produced in excess of 125 million dollars worth of metallic and nonmetallic mineral products since 1880, and unrecorded production of lead, silver and gold would increase this figure. Production of the five major metals, lead, silver, gold, copper, and zinc has accounted for nearly one-third of the total value. The county also has produced considerable tungsten ore and minor amounts of anti- mony, manganese, molybdenum, and quicksilver ores. Important non- metallic materials have been soda products, borates, talc, clays, and recently pumice. Other mineral products which have been exploited are asbestos, barite, limestone and marble, dolomite, gypsum, suKur, and slate.^i The lead-silver-zinc deposits are probably the most important metallic deposits in the county, and the earliest mining here was that of the lead-silver ores in the southern part. Five districts have been most productive. These are the Cerro Gordo, Darwin, Tecopa, Modoc, and Slate Range districts. In the Darwin district (which also produced tung- sten ore during the war) most of the lead-silver ore is enclosed in lime- »" Knopf, A., and Kirk, E., A geologic reconnaissance of the Inyo Range and the eastern slope of tlie southern Sierra Nevada, California, with a section on the stra- tigraphy of the Inyo Range: U. S. Geol. Survey Prof. Paper 110, 130 pp., 1918. 2" Knopf, A., Mineral resources of the Inyo and White Mountains, California: U. S. Geol. Survey Bull. 540, pp. 81-120, 1914. 3" Hopper, R. H., Geologic section from the Sierra Nevada to Death Valley, Cali- fornia: Geol. Soc. America Bull., vol. 58, pp. 383-432, 1947. 2* Noble, L. P., Ktiuctural features of the Virgin Springs area, Death Valley, California: Geol. Soc. America Bull., vol. 52, pp. 941-1000, 1941. 3» Noble, L. F., Rock formations of Death Valley, California: Science, vol. 80, pp. 173-178, 1934, no. 2069. *° Mason, J. F., Geology of the Tecopa area, southeastern California : Geol. Soc. America Bull., vol. 59, pp. 333-352, 1948. " Tucker, W. B., and Sampson, R. J., Mineral resources of Inyo County, California; California Div. Mines Rept. 34, pp. 368-500, 1938. 56 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 silicate rocks, and consists of argentiferous galena with its oxidation products and lesser amounts of sphalerite, pyrite, and chalcopyrite.^^ The Cerro Gordo district has been the largest producer of lead, silver, and zinc ores in the state, but production has been very little in recent years. Gold has been produced from the Argus, Panamint, and Inyo Ranges, and Sierra Nevada, but major activities have been curtailed since the war. Copper is produced principally from the concentrates of the silver, lead, and zinc operations. Tungsten occurs principally in the Pine Creek area of the Sierra Nevada and in the Tungsten Hills west of Bishop. This general area is one of the few known localities in the world where scheelite occurs in commercial quantities in contact metamorphic deposits. The ore occurs in limestone bodies which are parts of roof pendants projecting into the granitic rocks. Soda ash and trona are produced from Owens Lake. Borax mining from the colemanite beds in the Black Mountains east of Death Valley was active until 1926. Considerable talc is produced from this county, and the area around Talc City near Darwin is a major source of steatite talc, used in the manufacture of high-frequency insulators.^^ Significant Activities During 1947. Major metal-mining activities during the year were limited to lead-silver-zinc and tungsten ores. The Anaconda Copper Mining Company continued their operations at Dar- win, developing and mining the old Defiance, Independence, Thompson, and Bernon properties. Using the Radiore tunnel as their main haulage level, they continued production at a rate to give a 2-year average of 75 tons of shipping grade and 150 tons of milling grade ore per day. The milling ore required flotation of the primary sulfide lead and silver min- erals and subsequent sulfidization and flotation of the oxidized minerals. Plans were going ahead for a larger capacitj^ mill to operate on an all- sulfide ore to produce lead and zinc concentrates. Development work was extensive and included considerable diamond drilling. This company also took over the Shoshone mines from the Finley Company at Tecopa dur- ing the year and continued development on the Columbia No. 2 and War Eagle claims. Numerous lessees were active on lead properties through- out the county, and the Enterprise Mining Company continued explo- ration work on the Cerro Gordo mine. The United States Vanadium Corporation continued work on their Pine Creek mine, which is reported to be the world's largest tungsten mine, and which constitutes the largest reserve of scheelite ore in the United States. Mined from an elevation of 10,000 to 12,000 feet, the ore is transported via a three-section aerial tramway to the mill at an eleva- tion of 7,700 feet. The 1,500-ton mill produces in addition to scheelite, molybdenum and copper concentrates, the latter containing some silver and gold. The Sierra Talc and Clay Company operations at Tale City con- tinued with production of steatite-grade talc used in the manufacture of high-frequency insulators. In addition to their talc operations, this com- pany increased production of the bleaching clay from their deposit east of Olancha. The clay is mined by the room-and-pillar method with ^- Kollev, V. C, Geology and ore deposits of the Darwin silver-lead mining district, Inyo County, California: California Div. Mines Rept. 34, pp. 503-562, 1938. ^2 Wright, Lauren A., California talcs. Preprint of paper presented before Lo.s Angeles Fall meeting of Am. Inst. Mln. Eng., 8 pp., October 15, 1948. MINERAL RESOURCES AND PRODUCTION 57 slushers. It is used principally in the decolorizing and filtering of animal and vegetable oils. Numerous other talc deposits were mined throughout the county and accounted for a considerable portion of the state's total talc production. Pyrophyllite was processed b}' a grinding plant at Laws. Three companies, the Natural Soda Products Company at Keeler and Permanente Metals Company and Pittsburg Plate Glass Company near Cartago, produced soda ash and trona from the brines of Owens Lake. Boron minerals were also produced from these brines. Some sulphur was mined from the Last Chance Kange east of Big Pine and was ground for use as a soil conditioner. Dolomite was quarried and ground for roofing granules by the Inyo Marble Company operating just north of Keeler. Pumice, sand, and gravel, were produced from sev- eral areas for the building industry. R.M.S. Table IS. Mineral production from Inyo County during 194^ Product Quantity Value Copper- Gold... Lead Silver Stone Sulfur ore Talc and pyrophyllite. Zinc 232,000 pounds 1,974 troy ounces - 8,990 short tons... 1,235,998 troy ounces.. 69,320 short tons... 698 long tons 30,444 short tons 702 short tons... Unapportioned (boron minerals, raw clay, diatomite, fuller's earth, molybdemum, pumice, sand and gravel, sodium salts, and tungsten concentrates) Total value - $48,720 69,090 2,589,120 1,118,578 118,471 9,074 482,007 169,884 1,991,524 $6,596,468 KERN COUNTY General Geological Features. Kern County, containing 8,003 square miles, is in the south-central portion of the state. Its western boundary line is along the east slope of the Coast Ranges ; its southern boundary crosses the Tehachapi Mountains and continues some 50 miles into the Mojave Desert; its eastern boundary is wholly within the desert ; and its northern boundary crosses both the Sierra Nevada and the San Joaquin Valley. The Kern River and Poso Creek drain the west slope of the Sierra Nevada. These streams flow into the San Joaquin Valley where the water is used largely for irrigation. The eastern portion of the county contains a number of small basins of interior drainage, the principal ones being the Salt Dry Lake, Muroc Lake, and Rosamond Lake. Five geomorphic provinces extend into the county, the Coast Ranges on the west, Mojave Desert on the east and south, Basin Ranges on the northeast. Sierra Nevada and the Great Valley of California in the cen- tral and northern portions. The Great Vallej^ (here called the San Joa- quin Valley) lies between the Coast Ranges on the west and the Sierra Nevada on the east. It is an alluvial plain whose western border is under- lain by east-dipping Cretaceous and Cenozoic strata. The eastern border joins the Sierra Nevada whose westward-sloping bedrock dips under the alluvium and the Tertiary and Cretaceous sediments of the valley plain. 58 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 The great oil fields of the coimty have been developed principally along the margins of the Great Valley. The Sierra Nevada is terminated on the south by the Garlock fault which here marks the northern boundary of the Mojave Desert province. The core of the Sierra Nevada consists of Jurassic granitic rocks. Here at its southern end occasional patches of pre-Cretaceous metamorphies are exposed in the main mass of the range. To the west the bedrock dips under the sediments of the San Joaquin Valley. To the east, it is either flanked hy its own alhmal fans or by Tertiary and Quaternary volcanics. The portion of the Mojave Desert province within the county lies in the wedge formed by the junction of the southeastward-trending San Andreas fault and the Garlock fault which extends northeasterly along the foot of the El Paso jMountains. This desert area is an alluvial plain studded with isolated buttes and bordered on the west by the Tehachapi and El Paso Mountains. These buttes consist largely of Jurassic granitic rocks with some Miocene vol- canics and nonmariue sediments. Mineral Resources. The mineral production of Kern County is completely dominated by oil and natural gas. This production comes from pools in the foothills along the east, south, and west sides of the San Joaquin Valley. Since its inception in 1895 this industry has grown to gigantic proportions in Kern County, the total production through 1947 having been $2,208,553,000 worth of petroleum and more than $100,000,000 worth of natural gas. Borates in the form of borax and kernite are mined in large quan- tities a few miles northwest of Kramer, a station on the Santa Fe Railroad. These extensive deposits occur interbedded with Tertiary shales in the southeastern desert area of the county. A large portion of the world 's supply of these minerals is here produced. Cement is manu- factured at Monolith from a limestone deposit a short distance northeast of the plant. Clays are excavated from the beds of dry lakes in the south- eastern part of the county for use in oil-well mud. Kaolinized rhyolitie material is shipped from Jawbone Canyon for use in the ceramic industry. For many years silt from the floor of the San Joaquin Valley has been used in the manufacture of brick. Feldspar is produced from a pegmatite 2 miles northwest of Rosamond. Gold-silver ores are perhaps most numerous in their occurrence although largely confined to the eastern portion of the county, where they occur in veins in almost every type of igneous rock there found. In recent years, until the beginning of the war, the combined annual production of gold and silver approximated $3,500,000. Both gypsum and gj^psite have been produced in the county but now only gj^psite is being mined. There are several deposits of this material near the foot of the east slope of the Coast Ranges, where it has been extensively mined, notably in the vicinity of Lost Hills. It occurs also at the south end of Salt Dry Lake in the eastern portion of the county where, for a number of years, it has been excavated and shipped for use as a soil conditioner. Other deposits occur along Cottonwood Creek some 15 miles east of Bakersfield. Salt has long been produced at Saltdale by solar evaporation of the brines of Dry Salt Lake. Tungsten ores are widely distributed in the eastern portion of the county although production has practically ceased since the war. De- MINERAL RESOURCES AND PRODUCTION 59 posits have been worked in the Kandsburg area, the Sierra Nevada, the Piiite Mountains, and the Greenhorn Mountains. Tin has been found on the Tejon Ranch in the Tehachapi Mountains, but production has been negligible. Volcanic ash (pumicite) forms extensive beds in El Paso Mountains where it was mined for use in Old Dutch Cleanser until the fall of 1947. Other minerals occurring in the county which have either had some production or are believed to have commercial possibilities include anti- mon}^, arsenic, asbestos, copper, iron, lead-silver, lead-zinc, limestone, onyx, perlite, pumice, quicksilver, and rose-quartz. Significant Activities During 1947. The Pacific Coast Borax Com- pany continuously operated its mine at Boron, a few miles northwest of Kramer near the southeastern corner of the county. The Monolith Portland Cement Company 's plant at Monolith oper- ated continuously during the year. Antelope Materials Company (Macco Construction Company), Mojave Corporation and 0. L. Riley Company continue to ship rotary mud for oil-well drilling from Muroc and Rosamond Dry Lakes. Gypsite for agricultural use was produced in large quantities in the San Joaquin Valley, H. M. Holloway, Inc., of Lost Hills being the principal producer. Tropico Mines, Burton Bros., Lie, continued operation of their gold mine and mill west of Rosamond on a curtailed basis. The Cactus Queen mine was leased to this company and the ore remaining in the property will be extracted and treated in the Tropico mill. The mineral resources of Kern County have been more fully described in a recent report of the Division of Mines.^^ R.J.S. Tahle 19. Mineral production from Kern County during 1947 Product Quantity Value Clay products, heavy clay (other than pottery and refractories) Clay, raw Gold Gypsum, crude Natural gas Natural gasolire and allied products: Natural gasoline Liquefied petroleum gases Petroleum Sand and gravel Silver 213,475 short tons.. 6,228 troy ounces- 2352,977 short tons. - 86,289,000 M. cu. ft... Unapportioned (boron minerals, cement, pumice, salt, sihca [quartz], stone, and tungsten concentrates)-. 135,140,000 gallons 91,600,000 gallons 106,048,000 barrels 608,674 short tons.. 7,686 troy ounces- $746,372 217,980 =558,269 8,329,000 6,766,000 3,571,000 176,360,000 671,917 6,956 11,218,422 Total value. $208,445,916 1 U. S. Bureau of the Census not at liberty to publish figure. Value not included in county total. 2 A small quantity of crude gypsum pi educed in Kings County is included with Kern County. KINGS COUNTY General Geologic Features. Kings County lies at the southern end of San Joaquin Valley, and nearly all of its area is occupied by valley ■" Tucker, Sampson, and Oakeshott, Mineral resources of Kern County: California Jour. Mines and Geology, vol. 45, pp. 203-298, 194'J. 60 COUNTIES OF CALIFORNIA — 1 947 [Bull. 142 alluvium, so that little geology is to be seen at the surface. An exception is the southwest corner of the county, where a series of sediments is exposed, and where Pleistocene, Pliocene, Miocene, Eocene, and Cre- taceous strata may be seen. Drilling for petroleum has shown that a similar series exists below the alluvium of the valley. From a standpoint '^f mineral production, the outstanding geologic feature of Kings County is Kettleman Hills, a range 30 miles long and 5 to 6 miles wide, extending through Kings County and northwestward into Fresno County. These hills rise about 700 feet above the surrounding plains to an elevation above the sea of 1,400 feet. They have an anticlinal structure in Tertiary and probably Cretaceous strata and contain three domes, North Dome, Middle Dome, and South Dome. The trend of the South Dome is to the southeast toward the Lost Hills oil field of Kern County, and this is assumed to be a continuation of the same structure. Mineral Resources. Petroleum and natural gas were discovered at Kettleman North Dome in 1928, and the field has been one of California's major producers of both these mineral substances since that date. The wells penetrate Pleistocene and Pliocene formations to reach six pro- ductive horizons in the Miocene and one in the underlying Eocene. Recent production of other minerals has been very small, although deposits of clay suitable for brick, fullers earth, gypsum, mineral paint, and quicksilver are found in the county. Total production of quicksilver has amounted to a little more than 2,000 flasks from two mines near the common corner of Kings, Fresno, and Monterey Counties. Significant Activities During 1947. An outstanding development late in 1947 and early in 1948 was the completion of a successful oil well in the McAdams sand of Eocene age at Kettleman Middle Dome. Some gas accompanies the oil, but not as much as at Kettleman North Dome. The well was redrilled after tools had been lost in the hole to a depth of 12,281 feet, although at one time it was 12,389 feet deep and had penetrated the Eocene sand for 310 feet. C.V.A. Table 20. Mineral production from Kings County during 19J/7 Product Quantity Value Gypsum, crude Natural gas Natural gasoline and allied products: Natural gasoline Liquefied petroleum gases Petroleum 39,972,000 M. cu. ft.... 63,827,000 gallons 36,986,000 gallons 7,503,000 barrels $4,282,000 3,475,000 1,362,000 15,482,000 Total value. $24,601,000 1 A small quantity of crude gypsum produced in Kings County is included with Kern County. LAKE COUNTY General Geologic Features. Lake County is situated within the northern Coast Ranges province, and except for the portion south of the southern half of Clear Lake, is almost entirely covered with Franciscan sedimentary rocks, mostly shales and argillaceous sandstone. An area along the west shore of Clear Lake, extending some 12 miles south from Kelsey Creek and inland for about 6 miles, is Pleistocene rhyolite. There are patches of Recent basalt near the southern end of the lake and in MINERAL RESOURCES AND PRODUCTION 61 areas north aud south of Stubbs on the east shore of the lake. Narrow belts of serpentine and Tertiary volcanic rocks that trend northwest- ward occur in many places south of Clear Lake. There is a small area of Cretaceous rocks at the southern end of the lake. Beds of sand and gravel have been deposited at the mouths of the creeks emptying- into the lake. The geology of Lake County is shown on maps prepared by Forstner,^^ and Smith,^^ and the volcanic history of the Clear Lake area has been discussed by Anderson.'*' Mineral Resources. Borax has been produced from the beds of Borax Lake and Little Borax Lake near the south end of Clear Lake. Chromite has been mined from narrow stringers and small lenses in serpentine in areas west of Middleto^Ti and southeast of Lower Lake. A copper prospect showing azurite, malachite, and some sulphides occurs in limestone 4 miles northwest of Middletown. Gold and silver have been reported from assays of quartz samples taken from the Franciscan formation north of Upper Lake and west of Adams. Beds of limestone occur in the Franciscan formation in Burns Valley north of Lower Lake and near the Abbott quicksilver mine. Manganese minerals are found in lenses of chert in the Franciscan formation in many areas, and man- ganese has been mined from deposits north and west of Upper Lake, west of Middleto^vn, and north of Hullville. Lake County is noted for the number and variety of mineral springs, which occur in many parts of the county. Some springs have been developed as resorts ; the water is also bottled for sale. Cinnabar, metacinnabar, and native quicksilver occur in seams and fractures in brecciated Franciscan sandstones, cherts, and shales, and in the brecciated serpentine that intrudes them. Cinnabar is also found in shrinkage cracks in Pleistocene volcanic rocks covering crushed and brecciated sedimentary rocks. Most of the country rock is silicified. Much of the cinnabar is associated with pyrite, calcite, dolo- mite, and sulphur. Natural gas has been collected for local domestic use from seepages and shallow wells in the vicinit}^ of Kelseyville and Lower Lake. Sand and gravel pits are worked along Kelsey Creek and the basalt tailing from the Sulphur Bank mine is used in the manufacture of concrete building blocks. Sulphur has been produced from cavities and seams in the volcanic rock formation at the Sulphur Bank mine. The mines and mineral resources of Lake County have been described by Averill.^s Significant Activities During 19-17. Production of sand and gravel from deposits along Kelsey Creek increased during 1947. The material was used for roads and as concrete aggregate. Basalt rock mined from the waste dumps at the Sulphur Bank mine was crushed and screened for aggregate to be used in the manufacture of concrete building blocks. The Sulphur Bank and Great Western quicksilver mines were shut down during the year and their equipment was inventoried for sale. Mineral water was bottled for sale at three springs in Lake County (Bartlett Springs, Clearlake Oaks, and Witter Springs) during 1947. The resort buildings at Bartlett Springs were destroyed by fire during the year. . J.C.O.