Geology and geochemistry of Shuangwang breccia type orogenic gold deposit in the western Qinling belt, central China

摘要

The Shuangwang gold deposit in the western Qinling orogenic belt, central China, is localized between the Shangdan and Lixian-Shanyang regional faults and 1-5km far from the Xiba intrusion. Gold mineralization in the deposit principally developed in albite and ankerite-dominated cements that form the matrix to slate and limestone breccia blocks between two NW-trending local faults. Five breccias bodies are distributed along the 11.5-km-long and 4 to 500-m-wide. Available geochronological data show that the granitoids and the gold deposit formed between 215Ma and 168Ma. The analyses on C, H and O isotopes and the studies on ore-forming fluid inclusions reveal that ore-forming materials are probably derived from mantle and the dominant magmatic fluid were mixed with some amount of metamorphic fluid during the ore-forming process.