Physical-chemical study of the vein carbonates of the Vorontsovskoe gold deposit

A carbonate (calcite and dolomite) vein mineralization of the ore-bearing rocks of the Vorontsovskoe gold deposit (Northern Urals) was studied. Isotopic analysis of carbonates shows a trend toward the lightening of C and O isotopic composition from limestones to hydrothermal altered and magmatic rocks. Electron Paramagnetic Resonance study of carbonates showed that they differs in a width of Mn2+ spectrum because of structure defects. The C and O composition lightening corresponds to the carbonates with strong defects of structure which was formed by an ore-bearing fluid. In the carbonates, 3 types of rare-earth elements composition trends were observed: 1 - with negative Ce-anomaly; 2 - with positive Eu-anomaly; 3 - without anomalies. A negative Ce-anomaly possibly is related to the marine sediments, a positive Eu-anomaly suggests a magmatic origin of hydrothermal fluid.