PT formation conditions of polymetallic ores from the Pb-Zn-Fe Aktash skarn deposit (Western Karamazar, Tajikistan)

Abstract

Fluid inclusions are studied in calcite from magnetite ores and sulfde-carbonate veins of the Aktash sulfde-magnetite deposit (Western Karanazar, Tajikistan) to identify their formation conditions. The deposit is confned to a contact zone between carbonate (Upper Devonian–Lower Carboniferous dolomite and limestones) and intrusive rocks (Middle Carboniferous–Early Triassic granodiorites and porphyry granodiorites) of the Kansai ore feld. The fuid inclusion study showed that calcite of ore veins formed from moderately saline (4.4–10.8 wt. % NaCl-equiv.) aqueous Na-K ± Mg chloride fuids at a decreasing temperature from 300 to 160 °C. The homogenization temperatures of fuid inclusions are consistent with thermometric data for chlorite, which formed together with calcite (176–295 °C). Keywords: calcite, chlorite, formation conditions, fuid inclusions, polymetallic ores, magnetite ores, Aktash deposit, Western Karamazar.