TYPES AND METALLOGENIC REGULARITY OF GOLD DEPOSITS IN DERBUGAN METALLOGENIC BELT, DAXINGANLING MOUNTAINS

The Derbugan metallogenic belt is located in the eastern Mongolia-Xing'an orogenic belt, between the Ertix-Zuolun-Heihe suture zone and Mongolia-Okhotsk suture zone. Affected by Yanshanian movement, magmatic intrusion is heavy in the area, accompanied by intense gold mineralization in Derbugan area. Through the study of Shabaosi, Xiajibaogou and Xiaoyinuogaigou gold deposits, the paper analyzes the metallogenic characteristics and tectonic background of the gold deposits. The deposits can be classified into four types, including epi-mesothermal altered rock type hosted by sandstone, epithermal type hosted by volcanic rock, magmatic hydrothermal altered rock type related to deep intrusive complex, and tectonic-hydrothermal altered rock type occurred in ductile shear zone. The mineralization time of different types of gold deposits is concentrated mainly in Late Jurassic-Early Cretaceous of Yanshanian. According to the H-O-Pb isotope results, the ore-forming hydrothermal fluid is mainly the mixtures of magmatic water and atmospheric precipitation, with the metallogenic material from mantle-derived magma, mixed with minor crustal material. Different types of gold deposits have certain internal genetic relations and belong to the product of magmatic evolution at various stages in the same magmatic source region. The metallogenesis of the endogenetic deposits of nonferrous and precious metals in the region is characteristically distributed at the intersections of a series of parallel NE-trending structural belts and NW-trending secondary structures.