Geochemical Varieties of Hydrothermal Fluids in the Areas of Recent Volcanism

Abstract

Several geochemicalvarieties of hydrothermal fluids are identified in volcanic areas. water with moderate content of total dissolved solids (TDS up to 25 000 ppm) and relatively low temperature occur outsideof the zone of direct influence of volcanicchambersas well as alkaline low-mineralized fluids 1500 ppm) with temperature up to the boiling point. thermal water ,000 ppm, surround the extinct volcanic edifices and indicate the intensive thennometamorphic processes in the interior. Areas of active volcanism are marked by high-temperature fluids riched in (sometimes with is the predominant gas in acid fumarolic fluids discharged in the craters or on the slopes of active volcanoes , fluids with temperature up to distinguish the volcanic areaswithin oceanic rifts; these fluids associate most closely with the mantle melts discharge and are typical for submarine geothermal fields.