Department of Earth Sciences,the University of Hong Kong,Hong Kong,China

摘要

Huangshan ore field (including Huangshandong,Huangshanxi(Huangshan in some articles),Xiangshan and Huangshannan deposits) is the most potential region to seek for more than 1Mt of Nickel after Jinchuan in China.For the purpose of discussing the exploration direction in deep of Huangshandong Ni-Cu deposit,this paper focus on mineral chemistry of olivine,pyroxene,and feldspar to constrain the evolution of magma that forming the Huangshandong complex.Olivine and Orthopyroxene variations of rocks from three phases of Huangshandong complex show a differentiation of magma in the lower magma chamber.Ni content in olivine indicats that sulfide segregation have taken place when most olivine (Fo between 85.6 and 80,upper limit maybe higher) crystallized from the magma in the lower magma chamber.Olivine of troctolite and olivine norite (both are sulfide rich) of Intrusion II have moderate Fo and high content of olivine (wide range).In addition,the plagioclase of troctolite have higher Na2O and lower Al2O3,CaO content.Therefore,Fresh magma richer in Na2O pour into the lower magma may happened in the lower chamber which may force the magma in lower magma chamber intrude to Huangshandong dinstrict.In conclusion,ultramafic lithofacies of Huangshandong complex (Phase III) have the potential to found net-texture and massive ores (Intrusion II,III,IV) in the deep of Huangshandong complex and conduit connecting the complex and lower Magma chamber.