Greater Goldstrike, North Mines

Eureka County, Nevada, United States

GoldSilverArsenic

⌖ Show on map USGS source ↗

Description

Harry Ranspot of Atlas Minerals.

Commodities

PrimaryGold

SecondarySilver

TertiaryArsenic

Commodity typeM

Deposit

Deposit typedisseminated

Model173: Sediment-hosted Au

Deposit sizeL

Orebody formtabular to irregular disseminated

Ore controlHigh angle faults striking NW to NNW and associated fracturing are the major control, providing conduits for mineralizing fluids. Sporadic gold values occur along northeast trending structures. The major mineralization is within 3000 feet of the Goldstrike Stock, although it is believed to be considerably younger than the stock. Mineralization is also stratigraphically controlled along permeable sedimentary and hydrothermal breccias, bioclastic lenses, and calcareous siltstone horizons that intersect the faults. At Post, oxide ore generally occurs in the Rodeo Creek unit, while refractory sulfide ore typically occurs in the Popovich Formation. High grade mineralization (>1.0 opt Au) at Deep Post occurs along the sheared contact between sedimentary and intrusive rocks, and commonly below skarns and hornfels adjacent to the earlier intrusions; auriferous fluids apparently ponded beneath these impermeable lithologies.

Materials

Ore mineralsGold, Realgar, Quartz, Pyrite, Marcasite, Kaolinite, Dickite, Sericite, Illite, Alunite, Barite, Stibnite, Goethite, Hematite, Jarosite, Gypsum, Calcite

GangueOrpiment

Geology

Host rockLimestone,Carbonate,Mudstone,Siltstone,Sandstone,Chert · "Popovich Formation", "Vinini Formation", "Roberts Mountain Formation", "Rodeo Creek Unit"

Associated rockDiorite,Granodiorite,Quartz Monzonite,Porphyry · Goldstrike Stock

StructureRoberts Mountains thrust, High angle faults striking NW to NNW

Tectonic settingThe deposit formed along an ancient continental margin.

AlterationDecarbonitization and silicification of sedimentary host rocks are the predominant form of alteration. In the Betze-Post deposit, Arehart and others reported a 117 Ma age for gold mineralization, based on multiple 40Ar/ 39Ar and K/Ar dates on sericite, with no evidence of significant hydrothermal activity younger than 110 Ma.

Economic & production

Development statusProducer

Production years1977 - 1978; 1986 -present (2004)

First production1977

Last production2004

Discovery year1962

Identification

Deposit ID10310438

MRDS IDM242254

Alternate namesBetze, Bazza, West Bazza, Bazza Point, Screamer, Shalosky, Long Lac, Winston, Post, Lower Post, Deep Post, Rodeo, Goldbug, Barrel, East Griffin, West Griffin, Pancana, Betze-Post pit

RegionNA

Data scoreA

Coordinates40.97157, -116.36565

References

Nevada Division of Mine Inspection, Directory of Nevada Mine Operations Active During Calendar Year 1983, 1982, 1981.Bonham, H.F. 1986, NBMG Map 91.Bonham, H.F. 1988, in NBMG MI-1987.Mining Journal/Montagu Mining Finance Database 8/10/91"Goldstrike Mine", Mining Magazine, October 1989, v. 161, no. 4, p. 269-272."American Barrick - Growing Fast with Goldstrike", International Mining, April 1989, v. 6, no. 4, p. 9-11."Striking It Rich for American Barrick", Canadian Mining Journal, November 1989, v. 110, no. 11, p. 45-62.Newmont Gold Corporation 1990 Annual ReportHuspeni, J.R., 1990, Geology of the Post Gold Deposit [Abs]: Geology and Ore Deposits of the Great Basin, Reno/Sparks, Nevada, 1990, p. 67.Erdman, J.A., et al., 1990, Gallium, A Rediscovered Pathfinder Element; Example, Sagebrush over the Betze Gold Deposit, NV, Explore, no. 68, p. 5-6.McCarthy, J.H., et al., 1988, Evaluation of Multiple Geochemical Sample Media at the Betze Gold Deposit, Eureka County, Nevada, in Schinder, K.S., ed, USGS Research on Mineral Resources - 1989, Program and Abstracts, USGS Circular 1035, p. 45-47."A New Trend At Carlin", Mining Magazine, March 1988, P. 166.Rocky Mountain Pay Dirt, June 1988, P. 3a.NBMG, 1991, The Nevada Mineral Industry - 1990, NBMG Special Publication MI-1990.NBMG, 1994, MI-1993Nevada Division of Minerals, 1994American Barrick, 1993 Annual ReportLong, 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 disketteChristensen, O. D., Knutsen, G. C., and Ekburg, C. E., 1987, Disseminated Gold Deposits of the Carlin Trend, Eureka and Elko Counties, Nevada: Society of Mining Engineers Preprint Number 87-84, 7 p.Knutsen, G. C., Bettles, K. H., Sulfrian, C. E., and Zimmerman, C. J., 1987, Discovery and Geology of the Post Gold Deposit, Eureka County, Nevada: Society of Mining Engineers Preprint Number 87-86, 6 p.Barrick Gold Corp. 2002 Annual Report.Keith Bettles, 2002, Exploration and Geology, 1962 to 2002, at the Goldstrike Property, Carlin Trend, Nevada; in NBMG Bull. 111.Barrick 2005 Annual Report.