Ahnold says it's foah reahl.
The Motherlode district produced hardrock mines from which about 100 million ounces was mined. The mines were deep, narrow vein mines in granite/slate, and of respectable, usually higher grade. Most of the mining in that region was stopped about 1945.
***************************
Placer County, by Clarence A. Waring, Field Assistant. Field Work in October and November, 1915.
Introduction.
"North of the ‘Mother Lode’ region lies a district rich in mineral resources which needs only the stimulus of capital and stable, enterprising men to further develop its latent resources. Hydraulic mining, which occupied the early workers, is now ‘tied up’ as it were, by federal antidebris legislation, which disheartened the operators and caused stagnation of the mining industry in general….”
“Extending as it does, from the Sacramento Valley to the summit of the Sierras, Placer County offers a diversity of mining interests as well as a diversity of climate. In the middle fifties this county, with an estimated annual production of over $6,000,000 in gold, produced nearly one-tenth of all the yellow metal taken from the entire state. In 1914, with a production of $600,000 in gold, the county claims only about one-thirty-fifth of the total production…Together with the decrease of gold production has been the shifting of population. Iowa Hill, which in 1859 claimed a voting population of 1249, now has only 69, and other mining towns have dwindled to small villages or disappeared entirely. Over 500 mining claims were recorded in 1887. Only 135 properties are now active, i.e., being worked or having assessment work done (circa 1915)…Of the 135 active properties, 64 were said to be producing in 1916 and are distributed as follows: 6 quartz, 18 drift, 12 placer, 2 hydraulic 3 dredge, 2 chrome, 2 clay, 1 copper, 18 granite.
"A revival of interest in mining is coming, in fact, many of the old properties are now (circa 1915) being leased and work begun. This new activity will, no doubt, be more permanent than that of the old hydraulic days and the mining industry will be on a firm foundation for years to come. "
************************************************
"The Mother Lode gold district of central California yielded millions of ounces of gold from placer and bedrock mines. Gold was produced from a region covering nearly 8000 square miles on the western margin of the Sierra Nevada Mountains; beginning with the historic 1848 discoveries, and continuing until the second world war, when mining activities were halted throughout the district. Today, only a very small amount of gold is produced from the district, mostly by amateur prospectors.
Bedrock mining in the Mother Lode district was concentrated in the vicinity of the structural and lithologic contact between the Mariposa slate and the adjacent igneous and metamorphic rocks to the west. This steeply west-dipping zone is considered to be the “mother lode” of gold for the region. Many of the early bedrock mines were developed in the black Mariposa slate, and typically followed quartz veins.
Several mines have been redeveloped during the last decade to produce the black, graphitic slate. Industrial Minerals Co., along with Horseshoe A Mining, has redeveloped several of these old mines near Plymouth and Drytown, Amador County. The bedrock surrounding the former drift mines is removed using open-pit techniques. The ore is crushed by Horseshoe A at the mine site, and is then ground by IMCO at its Sacramento mill. This slate flour is used as filler in asphalt seal coat; and is also blended with clay pigments for use in some novel plastics applications. The platy structure and its blue/black color make it ideal filler for these applications. Approximately 100,000 tons per year is processed for use in this expanding industry. Vein quartz is high-graded during mining, and gold is recovered as a valuable, but minor by-product."
******************************************
canadiangeologicalfoundation.org
Grass Valley Curios
cgi.ebay.com
Tuolumne County, California
Many extraordinarily rich "lode" claims from the "California Mother Lode" district produced masses and leaves of bright native Gold from the 1850's, up until the present time. For background information on the Gold mining activities in Tuolumne County, see the "Mineralogical Record" magazine, Vol. 18, No. 1, P. 41 (special Gold II issue). This specimen is extra rich, and shows well from two directions, as demonstrated in the accompanying photos. The Gold and Quartz base of the specimen has been sawed in two directions, to reveal the thick veins of bright native Gold running through the pure white massive Quartz matrix. Lorraine Sofia collection.
Size: 1 1/8" tall, 1" wide, and 5/8" thick Weight: 23.35 grams (nearly 1 ounce)
Order Item MI-1066 Price: $490.00 (priced very reasonably at $21. / gram)
**********************
Other news from the Motherlode area
emgold.com
Emgold Mining Corporation (EMR-TSX-V) ("the Company") is pleased to report that integration of historic mine maps and other geologic data into a three-dimensional computer model from data collected during the time the Idaho-Maryland Mine was an active gold mining operation from 1851 to 1956 continues to indicate the presence of high-grade gold exploration targets at the Company's Idaho-Maryland Gold Mine in Grass Valley, California.
When completed, this comprehensive model will include geologic units, faults, veins, underground workings, assays and gold resources developed from the historic data, and geologic information from Emgold's two surface drilling programs. The data, which includes 220,000 feet of historic core drilling, 24,800 feet of core drilling conducted by Emgold, 36,000 assays, and 4,000 mine maps, is being digitized and entered into the MineSight(r) three-dimensional modeling software program. All work is under the supervision of Mr. Robert Pease, Professional Geologist (California), Chief Geologist for the Idaho-Maryland Project and a Qualified Person in accordance with National Instrument 43-101. |
