北山地区笔架山基性-超基性岩带地物化特征及含矿性研究

GEOPHYSICAL-CHEMICAL CHARACTERISTICS AND ORE POTENTIALITY OF BASIC-ULTRABASIC ROCK BELT IN BIJIASHAN, BEISHAN

笔架山岩带位于塔里木地块北山裂谷带内,受依格孜塔格深断裂控制。岩带处在重力异常梯度带边缘及区域磁异常分区界线附近,其上有铜、镍、钴、钒等综合异常。岩体为华力西晚期第二侵入次产物,由原始拉斑玄武岩浆分异而成,属正常或低铝贫碱钙的铁镁质至超铁镁质岩石系列。从岩石化学、矿物成分、矿化元素丰度、物化探异常等特征显示,具备铜、镍硫化矿床的成矿条件。

The Bijiasha basic-ultrabasic rock belt, located in the Beishan rift zone of Tarim Block, is controlled by the deep Igiztag Fracture. The comprehensive anomalies of Cu, Ni, Co, and V occur in this belt since it is near to the gradient zone of gravity anomaly and the boundary of regional magnetic anomaly divisions. The Bijiashan rock Belt body was formed by the differentiation of the primary tholeiitic magma of the second intrusion of Late variscan, and belongs to mafic-ultramafic rock series of low aluminum and calc-alkalic contents or of normal contents. The petrochemistry, mineral compositions, mineralization elements abundance and geophysical-chemical anomalies imply the ore-forming condition of Cu-Ni sulphide deposits