Gold Deposits of the World
Gold is one of the most economically important metals produced. As of 1991, more than 83% of gold consumption was for jewelry, 6% was used for medals and official coins, 6% was used in electronic equipment, 2.2% was used for dental materials, and 2.8% was consumed in a variety of industrial applications. These markets support an annual gold production of about 2,200 tons worth almost $25 billion ([Kesler, 1994] ). Globally, world gold production exceeded 2478 metric tons, or 79.667 million troy ounces in 2004 (Goldsheet Mining Directory - World Gold Production (more info) ).
There are many types of gold deposits (more info) including epithermal vein deposits, intrusion-related breccia pipes, mesothermal turbidite- and greenstone-hosted deposits, contact deposits (skarns), replacement deposits, disseminated ores, placers, and Archean banded-iron formation deposits. The Homestake Mine near the Pine Ridge Reservation is a banded-iron formation deposit.
To further investigate gold deposits, follow the links below.
Gold DepositsResources containing information on gold deposits.
Homestake Mine, located in western South Dakota, was created in 1876. Since the first production in 1878, almost 28 million troy ounces of gold have been extracted, worth 987 million dollars at present price causing the mine to be the most valuable in the United States.
Homestake Mine consists of several operations: an 8,000-foot deep underground mine, an open-pit mine, a mill, and a gold refinery. Operations turned to uranium mining in the 1950's, and the mine closed in 1989.
The gold deposits are a result of mineralization during the Precambrian period. The Homestake ore bodies are associated with banded iron formations and interlayered metavolcanic rocks. The schists of the Homestake Formation have experienced many stages of very tight folds. The ore bodies are central to zones of cross folding. Gold mineralization occurred in four stages of metamorphism and folding of the schists; the last stage occurred during intrusion of Tertiary dikes. The ore mineralization includes native gold, pyrite, arsenopyrite, pyrrhotite, with minor sphalerite and chalcopyrite. Mineralization occurs in vein and stockwork vein systems (Ridge, 1968 ).
To further investigate gold deposits at the Homestake mine, follow the links below.