Copper-Zinc deposits of the Penn Mine Calaveras County, California

Abstract

The Perm mine deposits in Calaveras County, Calif., are in slightly metamorphosed Jurassic volcanic rocks and intrusive quartz porphyry, Bedding, schistosity, and cleavage strike northwest and dip steeply northeastward. Two main types of faults are present: high-angle schistosity faults, and younger low-angle reverse faults. There are six main alteration zones, in which rocks have been sericitized, silicified, and pyritized. The ore bodies are sulphide replacement deposits either at contacts of.alteration zones, or along.faults within these zones. The ore bodies are steeply pitch-'"' ing lenses. Their pitch length ranges from 150 to 1,000 feet; breadth, from 100 to AGO feet; width,; from ^4 to^30 feet. The ore is a mixture of pyrite, sphalerite, chalcopyrite,-and a little bornite and tetrahedrite, Gangue minerals are barite, calcite, and quartz. t; Reserves.are estimated to be 245>100 tons of minings-gradevore^ and from 913>000 to £73,000 tons of low-grade ore. Two: types of areas favorable for exploration are listed: (1) extensions of kncwrLjore bodies, and (2) locations considered geologicalZy>ffayorable for the existencejof ore boidiesi? ^twarranted by the demand ifor copper and zinc, exploration of-these areas vis recommended.

Environmental factors affecting mercury in Camp Far West Reservoir, California, 2001-03

“…Along the north shore of CFWR are pyritic outcrops and small exploration pits associated with the same mineralized geologic unit. The Dairy Farm deposit is part of the Foothill Copper-Zinc Belt which extends along the western slope of the Sierra Nevada in eastern California (Heyl, 1948). Although total production history of this mine is not well documented (Loyd, 1995), mining began during the 1860s and continued in the early 1900s and 1930s.…”