A physicochemical model for the volcanic hydrothermal ore-forming system of epithermal gold-silver deposits, Northeastern Russia

For research on physicochemical processes of dissolution, transportation, and deposition of Au and Ag in epithermal deposits, a model containing 12 reservoirs was devised. The composition of deep-seated sub-ore solutions resulting from the "solution-andesite'' and "solution-rhyolite'' interaction was determined, showing that Au and Ag may be mobilized through the ore-bearing fluids, even from rocks with Clark concentration. Simulations allowed for the inference that the main source of reserves of Au and Ag in the Cretaceous Okhotsk-Chukotka volcanic plutonic belt (Russia's part of the Circum-Pacific belt) is magmatic chambers derived from the initial andesite magma. (C) 2000 Elsevier Science B.V. All rights reserved.