SILVER AND TELLURIUM CONCENTRATION IN HIGH-TEMPERATURE SOLUTIONS, AS SHOWN BY STUDY OF FLUID INCLUSIONS

Abstract

By studing multiphase inclusions in early quartz from pipe-like ore bodies of the Kochbulak deposit, the authors have obtained the first information on tellurium concentration in high-temperature ore-forming solutions, as well as data confirming their high silver content. These pipe-like ore bodies are in the northern part of the deposit, which is confined to a large volcanic structure filled by andesite, andesite-dacite and associated tuffs and lava-breccias of Middle to Late Carboniferous age. Thermometric and cryometric analyses of fluid inclusions revealed two main types of solutions that participated in the formation of the deposit. Characteristic features of solutions of the first type, which deposited quartz, chalcopyrite and finely divided gold of the early productive stage, were temperature below 390°C, dominance of sodium and potassium chlorides and low salt concentration. Solutions of the second type appeared only in the main productive mineralization stage, when the temperature of ore deposition had dropped to 225-200°C. In them was found a sizable quantity of magnesium and calcium chlorides a considerably higher salt concentration Accurate identification of the solid phases in the fluid inclusion in conjunction with an optical count of the proportion each phase allowed estimation of element concentrations in the ore-forming solution.