Goldstrike mine

Goldstrike Mine
Goldstrike Mine from space, 2016. The large Betze-Post open pit is labelled at top center. False color image: see source for details.
Location
Goldstrike Mine
Location in Nevada
Location Eureka County
State Nevada
Country United States
Coordinates 40°58′54″N 116°22′44″W / 40.981583°N 116.378964°W / 40.981583; -116.378964Coordinates: 40°58′54″N 116°22′44″W / 40.981583°N 116.378964°W / 40.981583; -116.378964
Production
Products Gold
Production 1,096,000 ounces (31,100 kg)
Financial year 2016[1]
History
Opened 1975
Owner
Company Barrick Gold
Website Goldstrike webpage
Year of acquisition 1986
Millerite- Arsenian Pyrite specimen from the underground Meikle mine, Goldstrike complex.

Goldstrike is a gold mine in Eureka County in north-eastern Nevada. It is located on the Carlin Trend, a prolific gold mining district. It is owned and operated by the world's largest gold mining company, Barrick Gold. Goldstrike is the largest gold mine in North America. Since Barrick acquired Goldstrike in 1986 it has produced 42 million ounces of gold.[1]

History

The first discovery of gold in the Goldstrike property was in 1962 by Atlas Minerals. Gold was first mined from the upper, well-oxidized portion of what became the Post deposit in 1975 by PanCana Minerals Ltd., in a small open-pit heap leach operation. In 1978, Western State Minerals Corporation entered into a joint venture (JV) with PanCana. The JV delineated ore reserves for the Post deposit in 1986. Barrick acquired 100% ownership of the property in December 1986, and mining started in 1987.[2][3]

Geology

The Goldstrike mine complex (including the Betze-Post-Screamer and Meikle-Rodeo deposits) is the largest Carlin-type mine in the world.[4] The Goldstrike mine adjoins Newmont Mining's Carlin mine complex. Goldstrike is northwest of the Carlin mine on the Carlin Trend.[5]

Like most Carlin type gold deposits in Nevada the gold was epithermally deposited in carbonate or silicate sedimentary rocks. The source of the heat was magmatic but the exact mechanism is still under debate. The Betze-Post deposits are up to 6,000 feet (1,800 m) long, 600 feet (180 m) thick and 800 feet (240 m) wide. In 2007 the average processed gold grade was 0.136 troy ounces (4.2 g) per ton of ore, with a recovery rate of 85.5%.[2]

Mining operations

The Goldstrike complex consists of three distinct mines: the large Betze-Post open-pit mine, and the Meikle and Rodeo underground mines. The ore from all three mines is milled, oxidixed in either a roaster or an autoclave, then leached in either a carbon-in-leach (CIL) cyanidation circuit or a calcium thiosulfate circuit.[1] The two treatment facilities treat ores from both the open pit and underground mines. Recovered gold is processed into doré on-site and shipped to outside refineries for processing into gold bullion.[2]

In 2015 the Betze-Post open-pit mine produced 642,493 oz (18,214.4 kg) of gold and 87,223 oz (2,472.7 kg) of silver, while the Meikle-Rodeo underground operations yielded 411,003 oz (11,651.7 kg) of gold and 17,749 oz (503.2 kg) of silver. This was 24% of the total 5,339,659 oz (151,376.8 kg) output of all gold mining operations in Nevada for 2015. In 2016 Goldstrike produced 1,096,000 ounces of gold,[6][1] making it the third largest gold mine in the world.

References

  1. 1 2 3 4 "Barrick 2017 Operations and Technical Update" (pdf). Barrick Gold. p. 170. Retrieved 22 March 2017.
  2. 1 2 3 Tsai, Peggy (September 2008). "Goldstrike Mine – Nevada's Giant Golden Goose" (PDF). Mining.com Magazine: 44–47. Retrieved 24 August 2011.
  3. ↑ Moore, Chester M.; et al. (16 March 2012). "Barrick Gold and Franco-Nevada - Goldstrike Mine, Project #1663". Toronto, Ontario: Roscoe Postle Associates Inc. Retrieved 22 March 2017.
  4. ↑ Kesler, Stephen E.; Riciputi, Lee C.; Ye, Zaojun (2005). "Evidence for a magmatic origin for Carlin-type gold deposits: isotopic composition of sulfur in the Betze-Post-Screamer Deposit, Nevada, USA" (PDF). Mineralium Deposita. 40: 127. doi:10.1007/s00126-005-0477-9.
  5. ↑ USGS, 1998, "Oreshoot Zoning in the Carlin-type Betze Orebody, Goldstrike Mine, Eureka County, Nevada", Open-File Report 98-620 (full text). See Figure 2 for mine locations and local geology
  6. ↑ Perry, Rick; Visher, Mike (1 November 2016). "Major Mines of Nevada 2015" (pdf). Nevada Division of Minerals. Nevada Bureau of Mines and Geology. Retrieved 24 January 2017.
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