The geological-genetic model of Carlin type gold deposits

The Carlin type gold deposits (CTGD) presents large metasomatic bodies of jasperoids in carbonate host rocks, that contain finely dispersed submicroscopic gold in disseminated pyrite or marcasite. The deposits occur in ore clusters that are concentrated along the rather long trends (faults) in the bottom plate of the regional Ro- berts Mountain thrust fault. In recent years, production of gold of this type deposits in the USA alone amounts to 9-10% of the world. The amount of gold produced and in reserves inventory exceeds 10000 tons. Exploration work over the past 10 years have shown that small-area of clusters may have considerable resources at depth. As part of the geological model discussed of the article highlights CTGD classification features, and in the genetic part - to the indicator factors of mineralization. The CTGD formed in a narrow time interval from 42 to 34 Ma, which corresponds to a change in the compression mode to expansion and rejuvenation of magmatism in northern Nevada. No known coeval porphyry copper, skarn or distal Ag-Pb-Zn mineralization in the clusters of CTGD. Similar hydrothermal alteration and ore paragenesis are typical for CTGD: dissolution and silicification of carbonate, sulphidation of Fe in the rock, formation of Au-bearing arsenian pyrite in closed system, and late in open-space deposition of orpiment, realgar and stibnite. Ore signature is Au-Tl-As-Hg-Sb-(Te)-Ва, with low Ag and base metals. There is a high correlation between Au and As, Au, and Tl. The Au/Ag ratio is about 10. Non-boiling ore fluids ranged from ~180 to 240oC and were of low salinity (mostly