Geology and Stable Isotope Geochemistry of the Dadonggou Pb-Zn Ore Deposit, Altay, Xinjiang, NW China

Based on detailed description of the geological features of the Dadonggou Pb-Zn ore deposit, this paper systematically studied C, H, O and S istopic compositions of the deposit. The orebody occurs in layers with the same trending as the strata. Ore bearing country rock is mainly volcanic sedimentary rock of the lower Devonian Kangbutiebu Formation and ore occurs in banded, disseminated and veinlet. Ore minerals consist simply of galena, sphalerite and pyrite, with zinc content relatively higher that of lead. Wall-rock alteration is well developed, and skarnization was closely related to Pb-Zn mineralization. According to the C, H, O and S isotopic composition of the ore, the δ34SV-CDTvalues of sulfides range from -22.3‰to +11.7‰, and δ13CV-PDB values of calcite rang from -4.2‰ to +0.4‰, the δ18OH2O values of quartz and calcite range from -11.4‰ to +7.6‰. It is suggested that the ore-forming fluid was mainly derived from mixture fluid of meteoric water with magma water. Combined with regional geological data, the ore deposit is considered to be formed in the intermittent period of volcanic-activities, and controlled by NW-trending faults, volcanic-sedimentary basins and hydrothermal fluid, and the deposit belong to a volcanic-sedimentary hosted massive sulfide deposit. The ore deposit was subject to regional metamorphim and hydrothermal fluid alteration.