Sources of Matter and Ore-Producing Fluid of the Tamunyer Gold–Sulfide Deposit (Northern Urals): Isotope Results

Abstract

The Tamunyer deposit is a typical example of gold–sulfide mineralization located in the lower lithologic–stratigraphic unit (S₂–D₁) of the Auerbach volcanic–plutonic belt. The latter comprises island–arc andesitic volcano–sediments, volcanics, and comagmatic intrusive formations. Carbonates have demonstrated intermediate values of δ¹³C between marine limestone and mantle. The quartz δ¹⁸O is in the range of 15.3–17.2‰. The δ³⁴S of sulfides from the beresitized volcano-sedimentary rocks and ores varies widely from –7.5 to 12‰. The calculated isotope compositions of H₂O, CO₂, and H₂S of the ore-bearing fluid imply two major sources of matter contributing to ore genesis: local rocks and foreign fluid. The ore-bearing fluid was formed by interaction and isotope equilibration between a deep magmatic fluid and marine carbonates (W/R ~ 1), with the contribution of sulfur from the volcano-sedimentary rocks.