PERMFILE134737 - Laserfiche WebLink

Home Browse Search

~ .~ Bad Boys of Cripple (~k Mining Company, Inc. • ,Limited Impact 110 rations Permit Application 6.3.3 EXHIBIT C -MINING PLAN (1) The Turquoise deposits in the Cripple Creek area have been recognized for many years. Turquoise deposits generally are shallow, less than 100 ft deep. It is a secondary mineral formed by the weathering of apatite a mineral found in igneous rock such as granite. Apatite is the source of phosphorus, in cool, near surface atmospheric conditions. The phosphorus goes into solution and these solutions come in contact with solutions of copper and combine in aluminum bearing rocks to form turquoise. In the Cripple Creek area, the origin of the gold deposits and the turquoise deposits are not related, however the same fractures in the rock that would host the gold deposits could also host the turquoise deposits, and gold can occur with the turquoise. the rock type in the area was breccia, a highly broken rock composed of fragments of granite or granite Schist. There have been historic mining activities on, and adjacent to the permit area. These activities, related to both gold and turquoise mining, have previously disturbed the area, and includes the access road to the site. Because the shallow deposits are relatively soft, they can easily be excavated, without explosives, with a large, track-mounted backhoe, such as a Case 225 Trackhoe. The procedure would be to dig a pit along a turquoise bearing trend. As the fresh rock is exposed each bucketful is carefully examined and the Turquoise is hand sorted from the rock. The face of the rock surface is examined and turquoise is carefully extracted by hand. Waste rock would then be stacked behind the backhoe. The nature of the operation is such that the mining production is measured in buckets with 50 pounds a good days results. Turquoise mining is generally done in campaigns with periods of time with no mining at all. Further sorting, cleaning, and marketing require larger amounts of time. The face of any excavation adjacent to the property lines would be mined with an adequate backslope to prevent slope failure. Experience in the district at the permit site, the Portland Pit and the Altman !Goldstar pit has shown that a 50 degree overall pit slope would be adequate. This would include a 15 ft safety bench, 8 ft. wide and a 1:1 backslope, and a 35 ft bench height with a 60 degree backslope for an average pit slope of 50 degrees at the mining depth of 50 ft. Mining is expected to be away from the property lines to the north and east. Mining has been conducted at this site in the past in close proximity to the property lines to a depth of approximately 40 ft, with no slope failures or damage to neighboring facilities. Page 10