Mineral and Geochemical Features of Zeolite-Siliceous Deposits at the Pauzhetka Geothermal Field, Southern Kamchatka

The Pauzhetka geothermal field was surveyed to study the mineral deposits that were formed as thermal water was discharged from well separators. We studied the compositions, structure, and geochemical properties of these sediments along the flow and in vertical cross sections of manmade “sinters”. It was found that, at the beginning of thermal water discharges, the sediments were composed of X-ray-amorphous mordenite–opal mixtures; later on, the sediments became wholly siliceous. The zeolite component of the mineral deposits determines their high sorption properties in relation to Au, Ag, Hg, As, Rb, Sr, Ba, Cs and other elements; the mordenite matrix receives sulfides of iron, silver, and copper. It is shown that the mineral deposits which were formed at the ground surface of the Pauzhetka geothermal field constitute an indicator of alkaline mineral-forming and ore-forming environment in the lower horizons of the Pauzhetka geothermal system.