Metallogenic Laws And Prospecting Direction In The Sankuanggou Copper Polymetallic Mining Area (Deposit), Heilongjiang Province

The Sankuanggou copper polymetallic deposit, located in the middle area clamped by Siberia plate, North China plate and Pacific plate, is occurred in the northwest part of Sankuanggou– Duobaoshan arc-like tectonic metallogenic belt. Duobaoshan large-scale porphyry-type copper deposit, Baoshan copper deposit, Zhengguang rock gold deposit, Sankuanggou Cu-Fe deposit and lots of mineral (mineralized) occurrence have been found in this metallogenic belt. In 2006, the Sankuanggou Cu-Fe deposit was classified as the first national prospecting project of successive mineral resources in crisis mine. And, in the process the implementing the this project, a lot of detailed geological data has been collected, the geological characteristics, mineralization law and prospecting indicator of Sankuanggou Cu-Fe deposit have been re-studied by using the theories and methods of structural geology, petrology, mineralogy, mineral deposits, volcanics facieology, geophysics, geochemistry, geology of fluid inclusions, isotope geology and other subjects, and through combining with the formers'studied results, as well as the characteristics of Huaduoshan circular structure and their relationships with mineralization have been discussed. Therefore, the future prospecting direction in this mining area has been defined, which provided a constructive guidance for finding large- or medium-sized copper polymetallic deposit in this area.Studies have suggested that the Huaduoshan circular structure is a tectonic- metallogenic system with good mineralization, which can be divided into three rings. In the outer ring, the gold mineralization with altered rock type has been found in the Ordovician - Devonian brittle - ductile deformation and metamorphic belt; In the middle ring, the skarn-type Cu-Fe-Au-Ag mineralization has occurred in the area nearby the intrusive contact zone between Late Triassic - Middle Jurassic tonalite rock-mass and sedimentary formation layered with marble lenses, and the veinlet disseminated Mo (Cu) mineralization has produced in the tonalite rockmass; And in the inner ring, volcanic hydrothermal - porphyry Mo (Cu) mineralization has appeared in the cryptoexplosive breccia rockmass which occurred in the marginal area of Huaduoshan volcanic edifices in Early Cretaceous Longjiang period. A metallogenic series with multi-phase, multi-origin, multi-minerals has been formed in the range of Huaduoshan circular structure.Sulfur and lead isotope studies have shown that, sulfur is mainly derived from the deep source of magma, with a very small amount of sulfur come from the strata; the lead belongs to the mixture lead that mixed with radiogenic lead, showing the characteristics of crust-mantle mixing lead, and reflecting the ore-forming materials of this deposit are dominated by the crust-mantle mixing source.The studies of fluid inclusion have indicated that, the ore-forming fluids are mainly magmatic hydrothermal, with varying degrees of precipitation mixed in the late mineralization stage. Ore-forming fluids generally belong to the system of high temperature, medium - high salinity and medium-density. And the ore-forming pressure and depth have shown that this mineral deposit formed in mesogene - shallow mineralization environment.