KARA GOLD ORE CLUSTER (EASTERN TRANSBAIKALIA): GEOCHEMICAL FEATURES OF ORES, THE RELATIONSHIP OF MAGMATISM WITH MINERALIZATION

Abstract

Dykes of the Amudzhikano-Sretenskiy complex (J3–K1) including hybrid porphyries are widely developed in the area of the Kara gold ore cluster. The parameters of the lanthanides distribution in them are close to those of ores of the quartz-tourmaline-pyrite association, indicating probable single sources of their formation. In hybrid porphyries, ΣTR is 52.24–123.35; in ores of the quartz-tourmaline-pyrite association ΣTR is 52.82–133.78. In hybrid porphyries, Eu/Sm is 0.18–0.65; in ores of the quartz-tourmaline-pyrite association Eu/Sm is 0.18–0.47. The degree of differentiation of magmatic chambers according to Eu/Eu* is 0.61-2.26 in dikes of hybrid porphyries; Eu/Eu* is 0.78–1.49 in ores of quartz-tourmaline-pyrite association. The represented data indicate that their magmatic chambers of dikes of hybrid porphyries and quartz-tourmaline-pyrite ores were not differentiated and, consequently, had a deep source. According to the geochemical composition, part of the Amudzhikano-Sretenskiy complex granite values corresponds to ore-bearing granites with goldmolybdenum mineralization. Ores of the actinolite-magnetite association are characterized by the highest gold contents among productive stages of gold mineralization. Close correlation relationships of Au with Zn, W, Mo were established in ores of the actinolite-magnetite association; in ores of the quartz-tourmaline-pyrite association – with Mo, Pb; in ores of the quartz-arsenopyrite association – with Pb, Mo, As, Ag.