DISTRIBUTION AND CHEMICAL COMPOSITION OF HALOTRICHITE IN GEOTHERMAL FIELDS OF KAMCHATKA

Halotrichite has been identified in geothermal fields of the Kambalny-Pauzhetka-Koshelev region, Bolshoi Semiachik complex, and Mutnovsky volcano (Kamchatka, Russia). forms efflorescence on soils heated up to 70°C, around steam-gas vents boiling springs. Tschermigite, rozenite, szomolnokite, gypsum, alunogen, barite, melanterite, hexahydrite, minerals copiapite, alunite voltaite groups were found close association with halotrichite. The chemical composition halotrichite samples from different is similar characterized by Mg substitution Fe2+ position, Fe2+:Mg ratio ranging 90:10 50:50, also Fe3+ Al position some samples, Al:Fe3+ reaching 85:15. a typical mineral low-temperature volcanic setting, formed as result alteration parent hydrothermal fluid represents an intermediate form crystallization leached elements. At same time, local conditions formation — such variations Eh, pH, surface temperature, elemental do not reflect or other thin typomorphic features mechanism probably identical both zones oxidation sulfide deposits.