| | Report (issue) | Nines and Prospects, Idaho Springs District Clear Creek and Gilpin Counties, Colorado Descriptions and Kapa...Energy Commission Introduction The Idoiho Springs mining district forms an important segment of tae Front...From 1859, when placer gold was discovered in Idaho Springs and lode gold in Central City, through 1959...from a 50-square-mile area that includes the Idaho Springs and adjacent districts to the north, west, and...and southwest. The adjacent Central City district, which produced ores valued at more than $100 million | | | Report (issue) | silty mudstone, commonly with lenses and laminae of pyrite o r pyrrhotite with minor amounts of other sulphides...suite is domi nated by sphalerite, galena, and pyrite with rare chalcopyrite . The other, whi ch i nclu...nclu des the vein i n this mine, contains pyrite, pyrrhotite and chalcopyrite with mi nor or rare galena...cuttings in the broad , pyrite-rich zone , commonly referred to as the pyrite halo . At Locality 3 there...there is abundant pyrite in both the altered microtonalite and the hard, baked siltstone of the Ffestiniog | | | Report (issue) | 190 0) East Grampians 1991 (0 85272 198 6) Lake District 1992 (0 85272 225 7) Southern Scotland 1993 (0...be interpreted in relation to the influence of mining activity and acid precipitation. Examples are given...highest values occurring around old metalliferous mining and smelting sites and in urban regions. The area...influence of geology and human activity, it is clear that the distribution of elements within stream...Welsh borders have a long history of metalliferous mining, with Bronze Age extraction having been proved |
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