S.N. Rychagov1, R.G. Davletbaev1, O.V. Kovina1, G.P. Koroleva2

1Institute of Volcanology and Seismology FED RAS, Petropavlovsk-Kamchatsky, 683006
2Institute of geochemistry by name A.P. Vinogradov SD RAS, Irkutsk, 664033

On example by Nizhne-Koshelevsky and Pauzhetsky geothermal deposits (Southern Kamchatka) studying the hydrothermal clays are continued. The data on hydrothermal clays chemical and mineralogical structures, distribution of metals in level-by-level sections up to depth of 1.7 m are received. Hydrothermal clays on a surface of thermal fields are formed with participation of acid hydrocarbonate-sulphatic solutions. Clays have non-uniform structure that depends on physical and chemical and temperature conditions of their formation. Hydrothermal clays forming powerful (on the average 1.5 - 1.7 m) and sustained on the thermal field horizon of argillizitic rocks (≥ n × 104 m2), serve not only as caprock in the structure of a geothermal deposit, but also are the complex geochemical barrier. Mineral-concentrators of ore elements are geothermal pyrite, amorphous and crystal phases of silica and, probably, aluminosilicates.

Keywords: Southern Kamchatka, hydrothermal deposit, clays, thermal anomaly