Jinchuan Copper-nickel Sulfide Deposits Of Platinum Group Element Geochemistry And Mineralization

Jinchuan deposit, as a world-class super-large deposit, it is the largest production base of platinum group elements in China, not only copper, nickel, platinum group elements metals and other extraordinary metals'product of enrichment, it is also the long-term result of a typical geological conditions and complete ore-forming mechanism. With the continuous deepening of the Jinchuan deposit exploration, tunnel and drilling exposed a lot of geological information, Provided a large number of new deposit geological information. With the rapid development of ore-forming theory and testing techniques, which laid a solid foundation for systematic in-depth study of Jinchuan copper-nickel sulfide deposit platinum group elements'enrichment mechanism and mineralization.In terms of ore-forming environment, diagenetic ore-forming epoch, rock characteristics, by making a comparative analysis of global nickel sulfide deposit, they agreed with the Jinchuan deposit, output environment for platform marginal rift, with the geological features of the platform. According to K-Ar method and Sm-Nd isotopic method, Speculated that Jinchuan rock formed in the late changchengian, of which rock chemistry, rare earth elements'feature, showed that the original ore in Jinchuan is a high magnesian tholeiitic basaltic magma.On the basis of the jinchuan deposit metallogenic model of predecessors summarized and proposed, application of the theory of liquid sulfide fractionation, closely contacted with magmatic origin, evolution and mantle source region, property and the tectonic setting; at the same time, carry out the measurement of rare earth elements, sulfur isotope, Fluid fluid inclusion composition and temperature, research the occurrence of platinum group elements, mineralogical characteristics, ore-forming geological conditions, focused on the geochemical behavior of magma formation and evolution of which platinum-group elements crystallization differentiation,research enrichment mechanism and mineralization of platinum group elements.Jinchuan ore-forming model, including igneous rocks'characteristics, power on the magma intrusion, mode on the magma intrusion, molten magma from the role of the deep, assimilation, crystallization differentiation, gravity hysteresis, bring about magma chamber generate layered System which is poor PGE+Au ore magma, with PGE+Au ore magma, rich PGE+Au ore magma and residual magmatic sulfide. Experienced early magmatic eruption, three periods'location magma intrusion, ore magma' invasion, liquation, aggregation, as well as the late hydrothermal gasification, superimposed hydrothermal mineralization and post-transformation etc. which lead to generate a complete, dynamic model of mineralization, formed double-ultrabasic rock and multiple orebody, this is metallogenic model of deep segregation-pulse invasive-repeated penetration. It is this leading to in a 1.34km2 small rock, ccurrenced the world-class super-large deposits. It is this ore-forming mechanism may be the only one to make "little rock becomes large ore" mechanism.