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Mineral resources and mineral resource potential of the South Providence Mountains Wilderness Study Area, San Bernardino County, California

1984; United States Department of the Interior; Linguagem: Inglês

10.3133/ofr84679

2332-4899

David M. Miller, L.L. Glick, Richard J. Goldfarb, Robert W. Simpson, Donald B. Hoover, D.C. Detra, J.C. Dohrenwend, S.R. Munts,

Hydrocarbon exploration and reservoir analysis

Geologic, geochemical, and geophysical evidence, together with a review of historical and recent mining and prospecting activities, suggests that much of the South Providence Mountains Wilderness Study Area has a wide range of potential for the occurrence of several types of undiscovered mineral resources.Eight mines and prospects in the study area have potential for gold, silver, lead, or copper resources.A high, moderate, or low potential for hydrothermal gold-copper mineral resources is ascribed to much of the study area.This mineralization is associated with plutonism and extensive alteration of the host granitoids.Several observations suggest that the exposed rocks may be distal to a gold-rich copper porphyry system, and much of the study area is given a low mineral resource potential for such a system.A high potential for epithermal volcanogenic gold resources is indicated for one small area of altered metavolcanic, plutonic, and hypabyssal rocks, and a moderate potential for epithermal gold resources is indicated for three other small areas.A low potential for placer gold resources is indicated for all alluvium in the area with particularly strong support for two small areas.Radioactive-mineral resources are possible in one area of granite, which is ascribed a low resource potential.A low potential for hydrocarbon resources is indicated for basinal sediments in a small part of the study area and an unknown potential exists for hydrocarbon deposits in Paleozoic strata.For other possible resources such as building stone and aggregate and geothermal resources there is unknown potential or no recognized potential.Mines in and immediately adjacent to the study area contain an estimated 200,000 tons of indicated and inferred marginal gold reserves and an additional 11,000 tons of marginally economic gold-bearing dump reserves.Thirteen mines have potential for additional resources.If a mine adjacent to the study area containing identified gold reserves were developed, a mill at that mine could process ore from possible resources in the study area, thus increasing the likelihood for development in the study area.Gold placer mining has occurred sporadically in and near the study area since the early 1900's.Of the approximately 100 placer claims filed since 1900, only two claim groups, the Valcerie adjacent to the study area and the Crucerro in the study area, were active in 1982.No production record exists for placer prospects in the southern Providence Mountains; total placer production is estimated to be less than 25 tr oz gold.Mining activity flourished during the 1930's and again in the 1960's, primarily in areas of previous mining.Interest in this area was supported by concomitant interest in the Providence Mountains to the north and the Gold Reef district to the southeast (Vredenburgh and others, 1981).The study area and vicinity was being assessed by several minerals-exploration companies in 1982.Mining production from the southern Providence Mountains consists primarily of precious metals with lesser copper and lead and small amounts of iron and fluorospar.Few production records exist for the various mines.The six recorded producers are the Bighorn, Buena Vista, Coarse Gold, Hidden Hill, Pilot, and Providence mines.Total production is approximately 8,627 oz of gold, 1,374 oz of silver, 19,889 lb of copper, 21,348 lb of lead, and less than 100 tons each of iron and fluorospar, valued in total at almost $4,000,000 at current prices.1/Major production of iron from the Vulcan mine, just north of the study area, is not included in these figures.Approximately 8,300 acres are currently (1982) under lease for oil and gas exploration.