Mineralization And Deep-process Of Huangshandong Nickel-Copper Deposit, East Tianshan

The north part of Xinjiang, is one of area which the nickel-copper sulfide deposit distributes the most thick and fast, and has become the most challenging nickel-copper sulfide deposit prospecting area in China as that people discovered Kalatongke and Huangshan where were the concentration of the nickel-copper sulfide deposits since the 1970', and combine with Qingbulake nickel-copper sulfide deposit. In the East Tianshan ore belt, the Huangshandong nickel-copper sulfide deposit is the largest and most representative deposit. The paper study on Petrology, Mineral Deposit, Petrochemistry and Mineral Deposit Geochemistry of the Huangshandong nickel-copper sulfide deposit by the numbers and concluded the following points:(1) The Huangshandong intrusion is mafic-ultramafic rocks, the main ore-bearing rocks are norite and pyroxene picrite, each lithofacies is the result of mineral crystal by the same source magma; the main minerals are olivine, pyroxene, plagioclase, hornblende and biotite, the content of each mineral have biggish change along with rock style.(2) The total concentration of platinum-group element (PGE) in ores and rocks is very low of Huangshandong nickel-copper sulfide deposit, the content of IPGE and PPGE is equality nearly; rocks and ores samples have similar mantle-normalized PGE patterns, the fractionation between IPGE and PPGE is low.(3) The magma source of Huangshandong mafic-ultramafic intrusion is depleted asthenosphere mantle, which contained dived oceanic crust at early, and partly melt formed the initial magma of Huangshandong is high MgO tholeiitic magma, which should be undepleted in PGE. Compared with continental tholeiite, simulating result reveals that the parental magma is visibly depleted in PGE, possibly duing to the sulfide pre- segregation of initial magma in deep crust.(4) The platinum-group elements geochemical character and petrochemical data show that crustal contamination and the fractionation of olivine and pyroxene in the magma revolution process of Huangshandong intrusion may be the main factors leading to S-saturation and sulfide segregation in deep crust.