Regional Metallogenic Regularity And Prospect Analysis Of Southern Middle Bangong Co-nujiang River Metallogenic Belt

Bangong Co-Nujiang River metallogenic belt is one of the21metallogenic belt in china.Along with the increasing research in recent years, a series of new deposits (points) have beendiscovered, showing tremendous exploration potential. But study of the deposits (points) isscattered, lacking of effective induction and consolidation. Through collect and inductpredecessors’ data, field surveys and samples collection, experiments tests and analysis inlaboratory, this paper comprehensively studies the geological features, chronology characteristics,geochemical characteristics and its implications, regional metallogenic regularity and prospectanalysis of southern middle Bangong Co-Nujiang River metallogenic belt. It has been finallyreached the following conclusions:(1). In the southern middle Bangong Co-Nujiang River metallogenic belt, theore-controlling strata of Fe-Ni-Cr-Co deposits associated with ultrabasic rocks and Ni-Cr-Fedeposits (points) associated with cherts are mainly Xiala Formation of Lower Permian(P1x),Quehala Group of Upper Triassic(T3Q), Xihu Group of Lower Jurassic(J1x), Rila Formation ofUpper Jurassic-Lower Cretaceous(J3-K1r). Magmatic rocks are mainly basic-ultrabasic rocks,such as harzburgite, dunite, gabbro and plagiogranite. While the ore-controlling strata ofskarn-type iron polymetallic deposits are mainly Langshan Formation(K1l) and DuoniFormation(K1d) of Lower Cretaceous. Magmatic rocks are mainly acidic rocks, such asmonzogranite, granodiorite and Quartz-diorite. Besides Qinglong skarn-type iron deposit, theother deposits in the study area are controlled by fracture of different directions. According totrend, the fracture are broadly divided into three groups, EW trending fracture, NW-SE trendingfracture and NE-SW trending fracture.(2). The ultrabasic rocks of Cebojiyi, Beilazhen and Darucuo are mainly harzburgite,harzburgite and dunite. The skarn types of Gengnai and other skarn-type deposits are mainlygarnet skarn, diopside skarn, quartz-diopside skarn and so on.(3). The mineralization or diagenetic age of typical deposits in the study area areYanshanian, which matched the whole Bangong Co-Nujiang River metallogenic belt.(4). The tectonic setting of Cebojiyi harzburgite and Darucuo dunite are island arcenvironment, while Beilazhen harzburgite are mid-ocean ridge environment. The three deposits’magma source are spinel amphibolite lherzolite source area. The cherts in the three deposits aremainly hydrothermal origin, and their forming environment are mid-ocean ridge environment.What’s more, the material source of Cebojiyi cherts are crust-mantle mixed source. Thegranites of each skarn-type iron deposits in the study area were formed in island-arc and collisionenvironment. The mineralization of iron, indium, bismuth are formed in the same period of hydrothermal activity, and they are all magmatic source.(5). It can be divided into three metallogenic series in the study area. They are theFe-Ni-Cr-Co mineralization series associated with ultrabasic rocks, the Ni-Cr-Fe mineralizationseries associated with cherts, and the Fe-Cu-In-Bi mineralization series associated with skarn.Correspondingly, It can be divided into three types of totally six prospecting areas in the studyarea. The study area is a Fe-Cr-Co-Ni mineralization belt associated with ultrabasic rocks, butalso a Fe-Cu-In-Bi mineralization belt associated with skarn. It is need to strengthen theevaluation and search works at Bangong Co-Nujiang River metallogenic belt, such as the Fe, Cr,Co, Ni resources associated with ultrabasic rocks in ophiolite, and the Fe, Cu, In, Bi resourcesassociated with skarn.