Metallogenetic Characteristics and Prospecting Potential of Major Metallic Minerals in Northwest China

Northwest China has abundant mineral resources with 309 large-, medium-size metallic ore deposits found.As centered by the Tarim block, the region connects with the Alashan massifsituated on the northwestern margin of the North China craton to its east, while to the north and south, there are the Phanerozoic orogenic systems consisting of numerous microb locks.The orogenic system to north is rep resented by the Hercynian Tianshan-Hinggan orogen that connects the Caledonian Altay-Ergun orogen with sandwich of the Junggar and llimassifs in between.The southern orogenic system is composed of the central and western Qinling-Qilian-Kunlun and Songpan-Ganzi orogens from north to south, with the middle Qilian and Qaidam massifs.The region belongs to a complex intracontinental orogenic belt.As a whole, northwest China is surrounded by the Paleo-Asian orogenic belt, the Tethyan orogenic belt and by the circum pacific orogenic zone to its north, south and east, respectively.The Proterozoic and Palaeozoic are two main metallogenic periods in the region.The main metallogenic types are magmaliquation Cu and Ni deposits, massive sulphide Cu and polymetallic deposits, sea floor exhalation Pb and Zn deposits, porphyry Cu and Mo deposits, skarn Wdeposits and hydrothermal alteration metallic deposits.According to regional geology and metallogenic evolution, we divided the metallogenic unit in northwest China in to 3 ore-forming domains, from north to south, they are: the Paleo-Asian metallogenic domain, the Qinling-Qilian-Kunlun metallogenic domain and Tethyan metallogen icdomain.The Paleo-Asian metallogenic domain is made up of Altay, west-southwest Tianshan, east Tianshan and Beishan metallogenic belts with the Junggar and Tarim basins, characterized by late Paleozoic endogenic mineralization.The Qinling-Qilian-Kunlun metallogenic domain contains west Kunlun-Altyn Tagh, Qilian, east Kunlun and Qinling metallogenic belts having the Qaidam basin in side, featured by Proterozoic and early Paleozoic mineralization.The Tethyan metallogenic domain consists mainly of north Sanjiang metallogenic belt located in southeast Qinghai-Tibet plateau, with middle Cenozoic being the major metallogenic period.Existing evidence and new development of the mineral resource investigation indicate that northwest China possesses favorable metallogenic conditions and a great potential for further prospecting work.We have to re-study the geological and metallogenic backg round and focus on key exploration work over 10 potential large-and super large-size metallic ore-forming areas in order to have great break throughs in prospecting.