Hydrothermal Clays of the Geothermal Fields of South Kamchatka: A New Approach and Study Results

摘要

Using the Pauzhetka and Nizhnee Koshelevskoe geothermal deposits (South Kamchatka), we studied physical—chemical characteristics of hydrothermal clays that form thick (on average, 1.5— 1.8 m) and spacious (up to few km2 in area) subsurface horizon with peculiar petrophysical and mineralogical— geochemical properties. It was established that the properties of hydrothermal clays are determined by their micro- and nanostructure, which is made up of nanoparticles of aluminosilicates, sulfates, accessory and ore minerals (primarily, sulfides and iron oxides), and amorphous phases. The subsurface horizon of hydrothermal clays represents a long-lived (up to 10 ka and more) highly dynamic colloidal—dispersed mineralogical— geochemical system, which reflects the interaction of deep-seated metalliferous fluids with geological medium in the supergene zone of geothermal deposits.