Mines and mineral resources of Amador County, Calaveras County, Tuolumne County (Google eBook)

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State printing office, 1915 - Mines and mineral resources - 180 pages
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Page 87 - An incline shaft has been sunk to a depth of 200 feet and two levels opened. There are two veins, one running N. 5 E. and the other N. 30 W., converging northward. The formation is clay slate on the footwall and amphibolite schist on the hanging-wall.
Page 58 - It is thirteen and a half miles from Milton. The owner is Josephine H. Sullivan, who bonded the property to Messrs. Lewis and Ben Williams. The vein channel is 100 feet wide, and consists of diabase and meta-diabase down to talcose schist. The ore bodies occur in lens-shaped masses from stringers to 20 feet in width. The shaft is 86 feet in vertical depth and then inclines 62 degrees for 239 feet, giving a total depth of 325 feet. The ores are principally sulphides, although carbonates and oxides...
Page 132 - ... by old shafts of shallow depth, which mark the many prospecting efforts of former periods. A few properties have shipped a little ore, mainly forty years ago. but no mines of note have yet been developed. Many of the deposits carry gold, and in a few gold affords the chief incentive to exploration. The western branch of the belt is the stronger one. From Copperopolis. in Calaveras County, it enters Tuolumne County at Byrne's Ferry, and passes through the Don Pedro district to the southeast. The...
Page 19 - Vein outcrops in a metadiabase; above the 290' level it passes into the Mariposa slates, where, apparently, the fissure was originally opened by a thrust fault with a throw of 120". One wall is a soft black slate, the other is slate or a greenstone schist. Two ore shoots have been developed; the north shoot 325' long, with average width of W; the south shoot 600' long, with average width of W.
Page 160 - An incline shaft has been sunk on the vein to a depth of 336 feet, with levels at 85', 151' and 318', from collar of shaft.
Page 13 - ... county. The gossan-capped vein is from 4 to 8 feet wide, courses east of north, dips 70 degrees to the east, and displays solid lenticular ore bodies, not mingled with the containing rock, as is the case at Copperopolis and mines elsewhere. The property has been opened by two shafts, one 150 and one 430 feet deep, and by 2000 feet of drifts on four levels, besides winzes and stopes. The richest ores were yielded in the workings at the south end of the mine, from which much ore running 15 to 25...
Page 54 - big trees" (Sequoia gigantea). All physical conditions are favorable to mining. The county is richly mineralized throughout, presenting several mineral belts and districts. The Mother Lode crosses the county along a 30-mile course, and in this county displays the characteristics of vast bodies of low and medium grade ore, presenting mining propositions of the sort now especially attractive to conservative mining capital. On this lode, at the northern side of the county, is the noted Gwin quartz mine;...
Page 132 - Lode belts, affording direct communication with the most populous and productive portions of tht county. Through the western end of the county the copper belt presents two branches. It enters the county from the north closer to the Mother Lode belt than elsewhere, being but two or three miles westward. The two divisions of the belt diverge somewhat in crossing the county southeasterly, and both are marked at intervals by outcrops of cupriferous veins and by old shafts of shallow depth, which mark...
Page 137 - Pachuca type agitators 1.0' x 30' are connected for continuous agitation. A spider with six radiating jets supplements the main working air jet as a help in starting at any time. The spider and main jets are connected with both high pressure air and high pressure water. An 8" x 10" Ingersoll-Rand compressor furnishes air at 40 pounds pressure for the agitators, air lift and vacuum filter.
Page 153 - ... Pearl claims were at one time individual properties, they have been developed more or less independently of one another. Surprise Claim.. This claim extends northward from the Quilp ground and the Surprise vein can be easily traced through both end lines of the claim. The Surprise incline shaft has been sunk to a depth of 700 feet on the vein. Near this shaft a highly productive ore-shoot was encountered during 1910 and a large production made. This apparently is the same ore-shoot which...

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