东天山早二叠世幔源岩浆活动及镁铁质杂岩体铜镍成矿潜力分析

Early Permian mantle derived magma and the Cu-Ni mineralizationpotentiality of the mafic complex in eastern Tianshan,Xinjiang

新疆东天山地区广泛发育早二叠世造山带岩浆铜镍硫化物矿床。东天山地区二叠纪幔源岩浆活动强烈,跨构造单元产出一套早二叠世火山岩、镁铁-超镁铁质杂岩体、镁铁质杂岩体和辉长-辉绿岩体。这套幔源岩浆为钙碱性岩浆,具有连续演化特征,具有喷出相和通道相地质特征。小型镁铁质-超美铁质杂岩体是目前东天山发现的主要的铜镍矿成矿岩体,部分镁铁质杂岩体作为岩浆通道,结晶分异好、含矿性好和剥蚀程度相对较低具有巨大找矿潜力。

The eastern Tianshan is one of important area that widely spread early Permian orogenic magmatic Cu-Ni sulfide de-posits in China. The early Permian mantle derived magmatic rocks,including volcanic rocks,mafic-ultramfic complex,mafic complexand gabbro. extensively distributed in all the tectonic belts of eastern Tianshan. These rocks are characterized mantle derived calc-alka-line series magma,the different types rocks evolution from the fractionation of the mantle derived parental magma,the ejection phaseare the volcanic rocks and the channel phase are different mafic and/or ultramafic complex and gabbro. To date,almost all the Cu-Nisulfide deposits formed in the mafic-ultramafic complex,a part of mafic complexes,as the magmatic channel phase,are characterizedby good crystallization-fractionation and mineralization,low level erosion,have great prospecting potentiality.