Amador County, Field work in September, 1914.
"Since the publication of the last report of the State Mining Bureau on the mineral resources of the State, there has been a general revival of interest in mining in this county, especially on the Mother Lode, where are located some of the deepest mines in the State. The following properties are under steady operation: Kennedy, Argonaut, South Eureka, Central Eureka, Keystone, Original Amador, Bunker Hill, Fremont, and Plymouth mines.
"During the past year the old Empire and Pacific mine at Plymouth has been reopened by the Plymouth Consolidated Gold Mines Company, Limited, of London, England.
"At this property a new mill has been constructed which is quite a departure from the present milling operations on the Mother Lode, where by means of heavy stamps, crushing through coarse screens, and regrinding with Hardinge mills the stamp duty has been increased from 5 tons to 15 tons per stamp. Then by means of classification an increased extraction is made. This new departure in milling will no doubt be the means of handling a larger tonage of low-grade ore at a profit. Another mine of interest that has resumed operations is the Keystone, which has reported past record of production of $17,000,000. The Treasure mine has been reopened, and after extensive development enough ore has been developed to assure that it will soon be on a producing basis. Besides the interest in gold mining, there has been an extensive development in clay deposits in the neighborhood of Ione, and a large tonnage of this material is being shipped to the different pottery works in the State for the manufacture of terra cotta, sewer pipe, tile and pottery, while quite a tonnage of fire clay is made into fire brick by the Ione Fire Brick Company. Aside from a small amount of prospecting there is but little activity on the copper belt.
Transportation Facilities (in Amador County).
"Communication by railroad with this county is especially good, the mines being within easy communication with San Francisco, Stockton, and Sacramento by means of the Southern Pacific Railroad from Galt to Ione and then over the Amador Central Railroad to Martell, which is within 2 miles of Jackson on the south and Sutter Creek on the north. There are good auto and wagon roads from Martell and Carbondale stations to the different mines.
Geology (of Amador County)
"There are three distinct lodes in Amador County. The principal one is the Central or Mother Lode belt, about 6 to 10 miles east of which is the East belt, occurring in the granite area near the Pioneer and Defender districts. About 8 miles west of the Mother Lode belt at Ranlett is the copper belt running in a northwesterly and southeasterly direction through the county, the ores of which occur in the form of copper sulphides associated with iron pyrites in amphibolite schist, and diabase.
"The quartz veins of the Mother Lode, may be divided into three classes: those occurring only in the black clay slates of the Mariposa beds, those occurring on the contact of the black slates on the west, and diabase on the east, and those in the amphibolite schist. The Plymouth Consolidated mines are an example of the first; the Keystone, Kennedy, Argonaut, South Eureka and Central Eureka are the second; while, the Zeila and Hardenburg are the third class. The general strike of the veins is from north and south to a northwesterly and southeasterly direction, with a dip of from 50 to 70 degrees to the east.
"The veins are in the form of quartz and stringer leads, with as a rule a heavy gouge on the footwall.
Storage of tailings (in Amador County)
"The mines along the lode have been put to a great expense in having to provide means for the storage of tailings. The Kennedy mine has installed a series of tailings elevators, for elevating the tailings from the mill to a storage reservoir, where they are impounded by a concrete dam 540 feet long and 50 feet high. All the other mines are buying land and building storage dams to take care of their tailings.
Production (in Amador County)
"The reported records of production of the following mines on the Mother Lode in Amador County are:
South Eureka, $2,000,000
Central Eureka, $2,000,000
Old Eureka, $20,000,000
Wildman & Mahoney, $3,500,000
South Spring Hill, $2,000,000
Bunker Hill, $3,000,000
"Amador County's mineral resources consist of asbestos, brick, chrome, clay, coal, copper, gold, lime, sandstone, silver, soapstone."
The following information is taken from the table on the insert page after page 4 entitled, "Amador County - Table of Mineral Production."
Lime Production in Amador County:
1904: 1,700 barrels, $1,700 value
1905: 1,000 barrels, $1,500
1906: 1,000 barrels, $1,200
1908: 800 barrels, $960
1909: 1,200 barrels, $1,440
1910: 1,400 barrels, $1,680
1911: 1,200 barrels, $1,500
1912: 800 barrels, $1,040
1913: 1,000 barrels, $1,200
Totals: 10,100 barrels, $12,220 value
Limestone Production in Amador County:
1907: 1,000 tons, $1,200 (value)
1908: 1,000 tons, $1,375
1910: 1,000 tons, $1,500
Totals: 3,000 tons, $4,075 (value)
Marble Production in Amador County:
1894: 25,941 cubic feet, $35,826 (value)
1895: 4,864 cubic feet, $6,566
1896: 4,389 cubic feet, $5,415
1897: 3,864 cubic feet, $6,280
1898: 2,850 cubic feet, $3,594
1899: 4,582 cubic feet, $7,925
1900: 4,103 cubic feet, $5,891
1901: 2,945 cubic feet, $4,630
1902: 6,300 cubic feet, $8,016
1903: 3,074 cubic feet, $5,379
1904: 4,785 cubic feet, $6,558
1905: 2,703 cubic feet, $3,950
Totals: 70,400 cubic feet, $100,030
Stone Industry Production in Amador County (stone only):
1910: Sandstone, $5,600
1910: Soapstone, $6,000
1911: Sandstone, $45,000
1912: Sandstone, $3,000
1912: Soapstone, $2,100
1913: Sandstone, $2,500
1913: Soapstone, $2,420
Total mineral production of Amador County from 1880 to 1913, inclusive (Stone only):
Stone industry: $243,792
Lime, Limestone, and Marble in Amador County:
"There are numerous lenses of limestone in the Calaveras formation in this county."
"Amador is one of the smallest counties in California, its total area being only 601 square miles. Yet it is one of the most prominent mineral counties of California, the total annual value of its mineral output being over $3,000,000.
"Foothill and mountain lands make up the county. Its western boundary touches Sacramento County in the rolling grounds of the low foothills. Its north and south boundaries are marked by the Cosumnes and the Mokelumne River respectively and its eastern line extends to the 7000 foot level of the Sierra Nevada Mountains.
"The soil of Amador is rich and productive. It is alluvial in character in many of the small and fertile valleys. In the mineral belt rich red lands predominate and in the upper foothill sections it is of decomposed granite. These lands will produce all kinds of deciduous fruits and are particularly adapted to the culture of pears and prunes up to the 2500 foot level and for apples in still higher altitudes.
"The climate of Amador County is like that of all the foothill sections of the Sacramento Valley. The rainy season commences in October and ends in May. The annual precipitation at Ione, which has an elevation of 287 feet, varies from 15 to 30 inches in a season. The precipitation increases as higher elevations are reached. The temperature in Summer at times reaches 100 degrees, but the atmosphere is dry and the heat is not oppressive. Cool evenings are the rule.
"There never has been a failure of any crop suited to Amador's soil and climatic conditions. All lines of farming are followed and the agricultural and horticultural products are increasing the county's wealth. There is plenty of opportunity for further extending the great industry of husbandry. Land is cheap and there is ample water available for irrigation.
"All crops find a ready market. Many of the growers devote their attention to supplying local markets in the mining districts. There is plenty of opportunity for developing profitable markets beyond the borders of the county.
"The county is at present (circa 1915) a heavy producer of cereals. Wheat, barley, oats and corn are all grown profitably. Much alfalfa and grain hay is also produced.
"The horticultural products of Amador include practically all the fruits grown in the Sacramento Valley. The full list includes apples, apricots, plums and prunes, pears, grapes, peaches and nectarines, oranges, lemons, olives, figs, almonds, English walnuts and cherries.
"Truck gardens are found in all the fertile little valleys and the owners find the mining towns profitable markets for their crops of vegetables and fruit.
"Stock raising is followed extensively. The foothills and mountain plateaus afford excellent pasturage the year round.
"Numerous streams cross the county from east to west, supplying ample water for mining operations and electric power development. Water is plentiful for irrigation but this valuable resource has yet (circa 1915) not yet been taken advantage of. One of the great power plants of the Pacific Gas and Electric Company is located at Electra, and here is developed 33,000 horse power of electricity, which is sent over long distance transmission lines to Stockton, San Jose and the cities surrounding San Francisco Bay.
"While the county has soil and climatic conditions that are favorable to the development of horticultural and agricultural resources, it is the mineral wealth that has made the name Amador famous. The Mother Lode, or great mineral belt of the Sierra Nevada Mountains, crosses the county from north to south for a distance of about twenty miles. Mining has been followed without interruption since 1848, and millions of dollars have been produced. Gold, silver and copper are extracted from the earth.
"During recent years (circa 1915) with the introduction of modern scientific methods, deep mining is followed extensively. Some of the best paying properties in the State are now being developed.
"Amador is one of the leading gold producing counties of California and its output is entirely from deep quartz mines. In this county are located some of the richest and deepest quartz mines in the world. The Kennedy mine at Jackson is operated at a vertical depth of 3900 feet, and is the deepest gold mine in the United States. It is equipped with a 100-stamp mill and employs steadily about 400 men.
"Directly south of the Kennedy Mine is the Argonaut, another large producer. This property is operated at a depth of 4600 feet on an incline, with a vertical depth of about 3000 feet. This mine is equipped with a 40-stamp mill and employs about 250 men. Its monthly production averages $60,000.
"North of these two mines at Sutter Creek are the South Eureka and Central Eureka Mines. The South Eureka is operated by electricity and its underground workings reach a depth of 2600 feet. It has an eight-stamp mill and employs 300 men. It produces $50,000 in gold a month (circa 1915).
"Further north are the Keystone, Original Amador, Bunker Hill and Fremont mines, all steady producers. At the northern boundary of the county is the Plymouth Consolidated. This is one of the oldest mines in California. It was a heavy producer in early days, but remained idle for a period of thirty years. Within the past two years it has been newly equipped with the latest machinery and is to-day operating on a large scale, with prospects of producing heavier in the future than in the past, even though it has produced more than $2,000,000.
"An excellent grade of potter's clay is found in Amador County near Ione, and is shipped in large quantities. Coal is also mined at Carbondale, and lime, marble and building stone exist in large quantities.
"The principal towns are Jackson, the county seat, Sutter Creek, Amador City, Drytown, Plymouth, Pieta, Volcano and Ione.
"A branch railroad which connects with the main line of the Southern Pacific Company at Galt, in Sacramento County, affords transportation facilities to the principal mining and agricultural centers.
"With a population of only about 10,000 Amador offers excellent opportunities to the farmer, the miner and the cattleman."
Area: 601 square miles.
Population: 7,793 (1920 census).
"The value of Amador County's mineral production decreased slightly from $3,452,640 in 1918 to $3,439,842, placing it number eight on the list of counties in the state as regards total value of mineral substances marketed. The drop was due to a decrease in gold output.
"Although having an output consisting of 9 different minerals, the leading product, gold, makes up approximately 95% of the entire total. Amador led the state in gold production in 1915, but was slightly exceeded in 1917 by Nevada and Yuba counties, and by Yuba in 1918-1919.
"The mineral resources of this county include asbestos, brick, chromite, clay, coal, copper, gold, lime, quartz crystals, glass-sand, sandstone, silver, soapstone, and miscellaneous stone.
"Commercial production for 1919 was as follows:"
(Headings for the information below are: Substance, Amount, and Value.)
Clay and clay products, ---, $142,523
Gold, ---, $,200,000 (estimated)
Silica, 8,440 tons, $67,366
Other minerals,* ---, $9,953
(Total value) $3,439,842
(* Includes coal, manganese, platinum, sandstone, and soapstone.)
"The limestone deposits of Amador County lie in two areas where the exposed formations were mapped many years ago by the U. S. Geological Survey under the name Calaveras, and were placed in the Carboniferous, principally on the evidence of a limited number of fossils found in the limestone. On the new State geologic map of California published by the State Division of Mines, the Calaveras is placed in the lower Carboniferous as 'Mississippian marine metasediments.' The term Calaveras has long been known among geologists and engineers as an unsatisfactory catchall for a number of formations which needed further geologic differentiation, but very little has ever been published to indicate that work has been done on the problem since the issuance of the Gold Belt folios. N. L. Taliaferro (43, p. 280)* of the Department of Geologic Sciences of the University of California, has lately alluded briefly to the subject as follows (see also discussion under Shasta County):
(* N. L. Taliaferro, "Manganese Deposits of the Sierra Nevada, Their Genesis and Metamorphism," California Division of Mines Bulletin 125, pp. 277-332, 20 figs, 1943.)
"'South of the Taylorsville region all the Paleozoic rocks, even where subdivided into formations, have been placed in the Calaveras group and assigned to the Carboniferous, generally on far from satisfactory evidence. Practically all of the fossils found have come from lenses of limestone; because of the recrystallization of the limestone the preservation is poor. Notwithstanding the fact that the fossils, in the great majority of cases, indicate nothing more than a Paleozoic age, the Calaveras invariably is stated to be Carboniferous on the legends of the various geologic maps of the Sierra Nevada. Undoubtedly the Carboniferous is represented, but the writer is of the opinion that at least a part of the Calaveras is Permian and a part pre-Carboniferous.'
"The limestone deposits in the low western foothill region of the county are numerous and small in size. They vary in composition from a high-calcium limestone to highly magnesian limestone close to dolomite. These deposits have been worked only on a limited scale and have produced some limestone, lime, and marble. Farther east, at Volcano and east of Fiddletown are two large deposits, the one at Volcano being a high-calcium limestone comparing favorably with the best in the state. This deposit, and part of the one farther north formed the bedrock of an ancient stream. When this stream was clogged by volcanic debris and ceased to function, the gravel and andesite protected the limestone so that it escaped the entire period of erosion since Tertiary time. It was finally exposed by hydraulic mining. Except for some marble production west of Volcano, deposits in that region have remained undeveloped because of their distance from railroads.
"The total production of lime and limestone from the county has not been recorded, but from 1904 to 1916 amounted to 12,640 barrels of lime and over 4000 tons of limestone. The value of marble produced during the same period was over $100,000. Later output of marble from a single quarry was not published."
"Amador County, 598 miles in extent, lies largely in the Sierra Nevada. The crest of the Sierra Nevada, which, in Amador County, attains an altitude of 9,371 feet, is in the eastern part, while the western part borders the alluvial plain of the San Joaquin Valley.
"The bedrock of the Sierra Nevada consists of steeply dipping, isoclinally folded rocks. Overlying the bedrock are nearly flat-lying Tertiary sediments and volcanic rocks. The pre-Tertiary rocks are composed of Carboniferous, Permian, and Jurassic metasediments and volcanics and late Jurassic igneous rocks, chiefly granodiorite. The Tertiary rocks are Eocene sands, clays, and auriferous gravels and Miocene and Pliocene volcanic rocks.
"The chief industries of Amador County are logging, agriculture, and mining. Since 1880 more than $165,500,000 worth of mineral products has been produced. The single commodity responsible for nearly 85 percent of this total is gold, most of which has been produced from that part of the Mother Lode gold belt between Jackson and Plymouth. Actually, this segment has been the richest part of the entire 115-mile length of the lode. Other important mineral products are clay, coal (lignite), and copper.
"The largest producers of gold have been the Kennedy, Argonaut, Keystone, and Plymouth mines, all of which have been inactive for nearly a decade. The Central Eureka mine which is now active (circa 1954) is one of the few Mother Lode gold mines which survived the government restriction order L-208 of 1942 and increased mining costs. Other past important gold producers have been the Fremont-Gover, Lincoln, Zeila, Oneida, Original Amador, South Eureka, Wildman, Mahoney, Treasure, and Bunker Hill mines. In the east belt the Belden, Rainbow, and Pioneer Lucky Strike mines were important producers. Several small east belt mines are now active (circa 1954). Substantial quantities of gold have been produced by gold dredges, hydraulic mines, drift mines, and by the re-working of old tailings. Several small dragline dredges are now active near Volcano.
"Clay is produced chiefly from Eocene beds in the western part of the county. The chief clay producers are Gladding McBean and Company, Western Refractories Company, and the Pacific Clay Products Company. Coal is now produced in the Buena Vista area by the American Lignite Products Company and the Humacid Company. Two mines, the Newton and Copper Hill, have produced most of the copper in Amador County.
"Other mineral products of Amador County are silver, chrome, manganese, iron ore, asbestos, sand and gravel, crushed rock, limestone and marble.
Introduction (Amador County)
"Amador County is an irregular-shaped area lying between the Mokelumne River on the south and the Cosumnes River on the north. It extends from Alpine County on the east to Sacramento and San Joaquin Counties on the west. Originally part of Calaveras County, Amador County was created on May 11, 1854. It was named for Jose Maria Amador, son of Sergeant Pedro Amador, a Spanish soldier who settled in California in 1771.
"The first authentic report of the presence of white men in Amador County was in 1846, when Captain John Sutter, accompanied by a small party of Indians and a few white men, conducted logging operations on the ridge between Sutter and Amador Creeks. A few months after the discovery of gold 45 miles to the north in 1848 prospectors began to swarm into what is now Amador County. By 1851 towns such as Drytown, Fiddletown, Jackson, and Volcano had been established."
Geography (of Amador County)
"Amador County embraces an area of 598 square miles. Altitude varies from 200 feet in the western part of the county to 9,371 feet, the altitude of Mokelumne Peak, in the east. The central area averages about 4,000 feet.
"In 1950 the population of Amador County was 9,151. Jackson, the county seat, is the largest town, with a population of 1,879. Other important towns are: Ione, 1,071, Sutter Creek, 1,151, Plymouth, 382, and Amador City, 151. The county is served by the Ione branch of the Southern Pacific railroad and the Amador Central railroad which connects with the Southern Pacific at Ione and extends to Martell. State Highway 49 runs north-south across the central portion of the western end. State Highway 88 extends the length of the county in a general east-west direction.."
Geology (of Amador County)
"Amador County lies almost entirely in the Sierra Nevada geomorphic province; only the extreme western portion lies in the Great Valley. From the Great Valley eastward, the range gradually rises to the glaciated crest in the vicinity of Mokelumne and Thimble Peaks, both of which lie above 9000 feet.
"The older rocks of the Sierra Nevada, commonly called the 'Bedrock series,' consist of isoclinally folded, complexly faulted metamorphic rocks of Paleozoic and Mesozoic ages, intruded by several types of igneous rocks, chiefly granitic. Unconformably overlying these rocks in the western portion of Amador County are much younger, nearly flat-lying Tertiary sediments. These nearly flat-lying sediments are commonly called 'Superjacent series.'
"In Amador County, the older metamorphic rocks are divided into the Calaveras and Amador (Taliaferro, 1943, pp. 282-284) groups and Mariposa formation. The Calaveras group includes all of the pre-Mesozoic rocks in this county while the Amador group and Mariposa formation are Jurassic. Taliaferro has divided the Amador group of Amador County into two distinctive formations: the Cosumnes and Logtown Ridge...."
Crushed Rock, Sand and Gravel* (in Amador County)
(* Please note: The sections relating to sand and gravel will not be included in this document.)
"Granodiorite, granite, and associated granitic rocks occur in the eastern part of Amador County. Broken and crushed granite is produced intermittently for use as road metal and fill. Coarse residual sand originating from the weathering of granite has been used in road repair and construction.
"Riprap composed of broken granodiorite was used in the construction of the roads owned by the Pacific Gas and Electric Company east of the West Point Power House. In 1951 a portable crushing plant operated by A. R. Milton produced crushed granite for use as road metal by the Amador County Road Department. Coarse sand originating from weathered granite has been produced by the Amador County Road Department from a pit in sec. 1, T. 6 N., R. 11 E., M.D.M., on the New York Ranch...."
Dimension Stone (in Amador County)
"Rhyolite, a fine-grained volcanic rock composed predominantly of light-colored feldspars and quartz, is occasionally utilized as dimensional stone. One such deposit in Amador County is the Evans deposit in the center of sec. 18, T. 7 N., R. 12 E., M.D.M., and extending to the northeast in sec. 17, T. 7 N., R. 12 E., M.D.M.
"This material is a well-compacted rhyolite tuff varying in color from white to buff. During the 1880's and 1890's, rhyolite from this deposit was quarried as a building stone for various buildings in the county, according to Elmer Evans, Jr., the owner.
Sandstone (in Amador County)
"Appreciable quantities of sandstone were produced in Amador County prior to 1914. Since that date only minor amounts have been produced intermittently. This early production was largely dimension stone for use in building construction.
"In the 1880's and 1890's, sandstone for dimension stone purposes was produced from a quarry in sec. 27, T. 5 N., R. 10 E., about 8 miles south of Ione. Even, fine-grained sandstone with a pleasing bright red color was produced from several quarry faces 15 to 20 feet high. Stone from this quarry was used in the construction of the Preston School of Industry in Ione, the California Bank Building in Sacramento, and the old Chronicle Building in San Francisco (Auburn, 1906, p. 117). Pure white sandstone having somewhat lower crushing strength than the red material may also be found in the quarries.
Serpentine (in Amador County)
"Small amounts of serpentine were produced in Amador County in the 1880's and 1890's for use as ornamental building stone. A yellowish-green to dark olive-green serpentine was quarried 2 miles west of Plymouth while a mottled variety of serpentine was quarried 1 ½ miles west of Sugar Loaf in the vicinity of Waits Station (Aubury, 1906, p. 147).
Slate (in Amador County)
"In 1941, G. J. Alexander of Amador City produced slate from a quarry near Martell. About 1900, some preliminary work was done on a slate quarry 1 ½ miles east of Ione. Except for these operations, there has been little production.
"Slate is used primarily as roofing granules and slabs, flagstone, table tops, blackboards, insulating material, and as mineral filler (Turner, 1950, p. 259). Most of the slate in Amador County is found in the Mariposa formation, which occurs in broad belts in the western part of the county.
Limestone and Marble (in Amador County)
"Lime (CaO) and limestone (CaCO3 + impurities), two closely allied materials, are the basis of a multimillion dollar business in California (Bowen, 1950, p. 171). Most lime is produced by calcining limestone. The largest consumer of lime is the portland cement industry which requires a high-calcium limestone. Much lime is used in mortar, plaster, and stucco.
"Other important uses of limestone are in agriculture as soil additives, in the steel industry as a basic flux in furnaces, in the beet sugar industry to remove impurities from the raw beet juice, and in the manufacture of industrial chemicals.
"Total production of lime and limestone from Amador County has not been recorded (Logan, 1947, p. 207). Between 1904 and 1915 production of lime averaged 1100 barrels per year. Since 1915 little or no limestone has been produced except in 1945 from the Allen property.
"In 1894 almost 26,000 cubic feet of marble were produced. From 1895 to 1905 marble production averaged slightly more than 4000 cubic feet per year. Since 1905 only small amounts of marble have been produced intermittently from the Dondero quarry.
"The limestone has a north to northwest trend and occurs in lensoid to tabular bodies which stand nearly vertical. Jointing is prominent in nearly all of the deposits. Those in the western foothills and at Volcano are bluish-gray in color and weather to a dull gray. Several of the deposits consist of marble that is white with irregular blue and gray streaks. West to Drytown is a deposit of red marble. Crinoids and corals of Paleozoic age have been found in two lenses on the Allen property south of Sutter Creek."
Soapstone and Talc (in Amador County)
"Small amounts of soapstone have been produced intermittently from Amador County since 1911. Although soapstone commonly contains a higher proportion of the mineral talc (basic magnesium silicate) than do some commercial 'talcs,' the term soapstone, as ordinarily used, implies the presence of impurities that prevent the use of the material as high-grade commercial talc (Wright, 1950, p. 277). Most of the soapstone produced in Amador County has been utilized as a roofing filler, soapstone pencils, and for other minor industrial purposes. Soapstone deposits are most commonly associated with serpentine and talc-actinolite schist.
"Light green talc crops out 6 miles northeast of Ione in sec. 4, T. 6 N., R. 10 E., M.D.M. In 1939, the Walter S. McLean Company of San Francisco did some work on a soapstone deposit east of Ione. D. E. Jones of Pine Grove produced soapstone during 1944."