ISOTOPIC COMPOSITION OF OXYGEN IN VEIN MINERALS OF THE IUL'TIN DEPOSIT

Abstract

In an earlier paper, we used an isotopic investigation of the mineral associations of a tin deposit of the cassiterite-silicate association to bring out a trend in the isotopic composition of oxygen in the aqueous phase of the fluid during its development. In addition, from experimental data on the resistance of cassiterite to recrystallization and on knowledge of the oxygen isotope fractionation factor in the synthesis of cassiterite, we concluded that it was preferable to use the isotopic characteristics of cassiterite to establish the character of the ore-generating fluids. The investigation reported here, which used specimens from the Iul'tin tin deposit (Chukotka), had the objective of identifying the genetic properties of the development or ore veins and evaluating the degree of equilibrium during generation of the mineral associations. A combination of oxygen-isotope and thermobarogeochemical methods of investigation was used for the purpose.