Thus, intermediate magma chambers, which are derivates of the primary andesite magma, are assumed to exist. In addition, meteoric waters, infiltrating to the root zone of the hydrothermal block through andesites and coming to the surface through fissure chammels, cannot be a potential source of Au epithermal deposits. Au hydrotherms of meteoric origin can participate in redistribution and remobilization of gold, early deposited, with its removal to the surface at the final stage of evolution of a hydrothermal system. At the final stage, the flow of deep fluids begins to run out.
Silver occurs both as chlorides and as hydrosulfides.
However, chlorides are predominant in the rhyolite fluid. Savel'eva V.B. W e have studied endogenic processes in the southeastern part of the Major Sayan Fault zone at the boundary of the Siberian Platform and Sayan-Baikal folded region. Early granitization took place under normal alkalinity with participation of rather reduced fluids, and postmagmatic fluid systems are carbon-enriched. 427 Davydov Yu. This dependence is similar to that between the dolomite content and porosity of the Midale beds in the Charles oil field.