Study On Origin Of Xiangshan Copper-Nickel Sulfide-Ti-Fe Oxide Deposits Petrogenesis And Mineralization Of Xiangshan In Eastern Tianshan

Eastern Tianshan is an important Cu-Ni-Au-Mo-Fe ore-concentrated area. Exist a seriesof magmatic copper-nickel sulfide deposit, such as: Tulaergen, Hulu, Huangshan,Huangshandong, Huangshannan, Xiangshan, Tudun, Baishiquan, Tianyu. Meanwhile foundsome Ti-Fe oxide mineralization, such as: Weiya, Niumaoquan, Yamansu. However,Medium-sized Cu-Ni sulfide deposit occur in the central part of Xiangshan intrusion, andsmall sized Cu-Ni sulfide deposit and Fe-Ti oxide deposit occur in the western part ofXiangshan intrusion. Chronology, the structural regularity of controlling rock and controllingorebody, petrography, lithogenesis, metallogenic characteristics, ore genesis have been doneabout Xiangshan intrusion. The paper focusing on petrography, mineral petrography, mineralcrystallochemistry, geochemistry, isotope geochemistry, compare with the typicalcopper-nickel sulfide deposits and Fe-Ti oxide deposits, through the depth study by mineralassemblage, mineral crystallization temperature and order, magma source, parent magmacomposition, degree of mantle melting, hydrothermal alteration, assimilation and discuss thedepth process and mineralization of Xiangshan intrusion. The following are the main results:(1) The main rock-forming minerals of Xiangshan intrusion are olivine, orthopyroxene,clinopyroxene, amphibole and plagioclase. We obtain the development sequences of mineralsis olivineâ†'orthopyroxeneâ†'clinopyxeneâ†'plagioclaseâ†'amphibole. The main ore mineralsinclude pyrrhotites, chalcopyrite, pyrite, pentlandite, magnetite and ilmenite, etc.Mainore-forming elements in the ore mineral is different in different types of ore.(2) Xiangshan complex are products of comagmatic evolution. In general, Thecontents of SiO2, TiO2, P2O5,∑REE, the degree of the LREEs fractionation, the degree of theHREEs fractionation, the degree of the REEs distribution curve, and loss or enrichment ofeuropium for every lithofacies from Xiangshanxiâ†'Xiangshanzhongâ†'Xiangshandong arereduced. However, the contents of MgO, m/f, Mg#are elevated.(3) The magma source of Xiangshan intrusion is depleted mantle or aesethenospheremantle. The metasomatism of the subducted slab dehydration and partial melting, which canapply some subducted components and liquid, therefore, the Xiangshan intrusion retainedsome information of ialand arc.(4) The content of MgO is about10.70%, and the content of FeO is about10.66%in theparent magma, which suggest that it belongs to high MgO basaltic magma. The magma iscontaminated by country rock or crust when the magma riding and emplacing, the degree ofcontamination about5%~10%. (5) Crustal contamination and exotic rock sulfur is added to the system with thepromotion of the role of sulfur saturation, but limited contribution, the main factors for thesulfur-saturated magma crystallization. The degree of sulfide liquation from Xiangshandongbetween Xiangshanzhong and Xiangshanxi, therefore, the possibility exists to find ore bodiesfor Xiangshandong.(6) The copper-nickel sulfide deposits and Ti-Fe oxide deposits is the product of adiferent evolutionary stages comagmatic. The Ti-Fe oxide deposits is due late magmaticevolution of the residual magma Ti, Fe, fO2increases, Ti-Fe oxide followed by crystallization,enriched.