新疆东天山香山岩体橄榄石特征及其成因意义  

Characteristics and Genetic Significances of Olivine from Xiangshan Complex in Eastern Tianshan,Xinjiang

作　　者：姜超[1] 钱壮志[1] 张江江[1] 孙涛[2] 徐刚[1] 孟德明[1] 

机构地区：[1]长安大学地球科学与资源学院,西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [2]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室,北京100037

出　　处：《现代地质》2014年第3期478-488,共11页Geoscience

基　　金：中国地质调查局地质大调查项目(1212011085061);国家自然科学基金项目(41372101);中国博士后科学基金资助项目(2013M541001)

摘　　要：新疆东天山香山镁铁-超镁铁杂岩体位于东天山镜儿泉—黄山镁铁-超镁铁质岩带的西段，由香山东、香山中、香山西3个岩体组成。其中香山中产出中型铜镍矿，香山西为小型铜镍-钒钛铁复合型矿床。香山岩体橄榄石为贵橄榄石，Fo值多为81.90-85.66，Ni含量为638×10^-6-2 283×10^-6。模拟计算得出香山岩体母岩浆w（MgO）=10.70%，w（FeO）=10.66%，属于高镁玄武质岩浆。香山岩体橄榄石中Ni含量的最大值为2 283×10^-6，母岩浆中Ni含量为326×10^-6，是由原始地幔发生14%的部分熔融而成。香山岩体在橄榄石结晶过程中伴随硫化物熔离，隙间硅酸盐和硫化物对橄榄石作用明显，造成早期结晶橄榄石成分改变。The Xiangshan mafic-ultramafic complex was located in western part of Jing’erquan-Huangshan ma-fic-ultramafic rock belt, composed of the eastern part （Xiangshandong）, the central part （Xiangshanzhong）, and the western part （Xiangshanxi）. Midium sized Cu-Ni sulfide deposits occur in the central part, and small sized Cu-Ni sulfide deposits and Fe-Ti-V oxide deposit occur in the western part. Electron microprobe analyses of olivine show that almost all the olivine crystals are chrysolite with the forsterite content （Fo） ranging from 81.90 to 85.66 and the Ni content ranging from 638×10^-6 to 2,283×10^-6. The content of MgO is about 10.70%, and the content of FeO is about 10.66% in the parent magma, which suggests that it belongs to high MgO basaltic magma.The Ni content with a maximum of 2,283×10^-6 in olivine indicates that the Ni content of the primitive magma is 326×10^-6; therefore, we can speculated that the primitive magma occured when 14% of the primitive mantle was melted. Sulfide separation and fractional crystallization happened simultaneously. The re-equilibration of olivine from silicate liquid or sulfide liquid should be taken as an important factor for olivine composition.

关 键 词：香山岩体 橄榄石 成分特征 东天山 新疆 

分 类 号：P588.12[天文地球—岩石学] P581[天文地球—地质学]