LJ Ridge Deposit

White Pine County, Nevada, United States

GoldSilverCopperZincArsenicAntimonyMercuryBismuthTellurium

⌖ Show on map USGS source ↗

Commodities

PrimaryGold, Silver

TertiaryCopper, Zinc, Arsenic, Antimony, Mercury, Bismuth, Tellurium

Commodity typeM

Deposit

Deposit typesediment-hosted gold

Model75: Distal disseminated Ag-Au

Deposit sizeS

Orebody formtabular to irregular.

Ore controlMineralization is structurally controlled. The dominant structural trend is N45W, but there are NE-, N-S, and E-W-trending structures as well. The E-W structures show the youngest period of movement, some of which is post-ore

Materials

Ore mineralsGold

GangueQuartz, Pyrite, Arsenopyrite, Sericite, Sphalerite, Chalcopyrite, Tetrahedrite, Galena

Geology

Host rockShale,Limestone · "Dunderberg Shale", "Windfall Formation"

Associated rockQuartz Monzonite,Lamprophyre,Aplite · Bald Mountain Stock

StructureThe Bald Mountain district is located in an area of thinned crust along the eastern side of the Late Proterozoic rift that split the North American craton. It is also in the west-central portion of the Late Devonian-Early Mississippian Antler foreland basin, and near the eastern edge of deformation related to the late Paleozoic Humboldt orogeny To the west of the Bald Mountain district, geologic interpretations are dominated by recognition of Paleozoic deformation, whereas to the east, interpretations emphasize Mesozoic contraction and plutonism and Tertiary extension.

Tectonic settingThe Bald Mountain district is located in an area of thinned crust along the eastern side of the Late Proterozoic rift that split the North American craton. It is also in the west-central portion of the Late Devonian-Early Mississippian Antler foreland basin, and near the eastern edge of deformation related to the late Paleozoic Humboldt orogeny.

AlterationAlteration consists predominantly of silicification, argillization, and potassic alteration.

Economic & production

Development statusProducer

Production years1983; 1985 - 2000

First production1983

Last production2000

Identification

Deposit ID10310447

Alternate namesBald Mountain Mine Project

RegionNA

Data scoreB

Coordinates39.96659, -115.59589

References

Hitchborn and others, 1996, Geology and Gold Deposits of the Bald Mountain Mining District, White Pine County, Nevada, in Geology and Ore Deposits of the American Cordillera Symposium Proceedings, eds. A. Coyner and P. Fahey.The Geological Society of Nevada 1996 Spring Field trip, Geology and Gold Deposits of Eastern Nevada, GSN Special Publication No. 23.Hose, Blake, and Smith, 1976, Geology and Mineral Resources of White Pine County, Nevada, NBMG Bulletin 85.Hill, J. M., 1916, Notes on some Mining Districts in Eastern Nevada, USGS Bull. 648, p. 152-161.Dean, D. A., Benedetto, K. M. F., Durgin, D. C., 1991, Part Two: Ely - Bald Mountain - Ely Road Log, in Buffa, R. and Coyner, A., eds., Geology and Ore Deposits of the Great Basin - Field Trip Guidebook Compendium, The Geological Society of Nevada, Reno, p. 136-162. 1981.NBMG Map M84.NBMG, 1994, MI-1993Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.Nutt, C.J., Hofstra, A.H., Hart, K.S., and Mortensen, J.K., 2000, Structural setting and genesis of gold deposits in the Bald Mountain-Alligator Ridge area, east-central Nevada, in Cluer, J.K., Price, J.G., Struhsacker, E.M., Hardyman, R.F., and Morris, C.L., eds., Geology and Ore Deposits 2000: The Great Basin and Beyond: Geological Society of Nevada Symposium Proceedings, May 15-18, 2000, p. 513-537.BLM, 2004, Bald Mountain Mine Exploration Program Programmatic Environmental Assessment NV040-04-023, Case File # N78825.