Bulk Mineable Gold Deposits of the Western United States
Bulk mineable gold deposits in the western United States contain reserves of more than 55 million oz (1,710 metric tons) Au and produce more than 3 million oz (93,300 kg) Au/yr. They can be subdivided into five main deposit types: porphyry-related, sediment-hosted (includes deposits of the Carlin type), metamorphic-hosted, volcanic-hosted, and hot spring gold deposits. Each deposit type can be further divided into several deposit subtypes.
Examples of porphyry-related gold deposits are Zortman-Landusky in Montana and the Fortitude and McCoy skarn-hosted gold deposits in Nevada. Major sediment-hosted gold deposits in the western United States occur mainly in Nevada and include the world-class gold deposits located within the Carlin and Getchell trends. Metamorphic deposits include Mother Lode and Mesquite types, located principally in California and Arizona. Volcanic-hosted deposits can be subdivided into three main deposit subtypes: high sulfur deposits such as Summitville, Colorado, and Paradise Peak, Nevada; low sulfur deposits such as Round Mountain, Nevada; and alkalic deposits such as Cripple Creek, Colorado. Hot spring gold deposits are typified by the McLaughlin gold deposit in northern California.