MACROCOMPONENT COMPOSITION AND GENESIS OF PORE SOLUTIONS IN HYDROTHERMAL CLAYS OF THE PAUZHETKA GEOTHERMAL SYSTEM (Southern Kamchatka)
S.N. Rychagov, A.V. Sergeeva, O.V. Kravchenko, A.A. Kuz’mina
Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences, Petropavlovsk-Kamchatsky, Russia
Keywords: Pore solutions, water extracts, hydrothermal clays, geothermal system, metal-bearing alkaline fluid, mineral formation
Abstract
We have studied the macrocomponent composition of pore solutions in hydrothermal clays forming extended thick strata in the thermal fields of the Pauzhetka geothermal system. Two zones have been identified in the vertical sections of the clay strata, which differ in the physicochemical parameters, composition, and formation conditions of pore solutions. It is shown that the pH of the solutions plays a crucial role in the change of their macrocomponent composition with depth. The conclusion is drawn that the pore solutions resulted from the direct impact of deep-level infiltrating thermal waters on the matrix of hydrothermal clays, which led to the redistribution of elements between the rock and the contact solution. Along with the general regularities, we have established significantly different conditions of formation of pore solutions in the Upper Pauzhetka and East Pauzhetka thermal fields, which is due to the different geologic positions and hydrogeochemical regimes of these fields.
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