东天山白山钼矿地球化学特征及地质意义

Geochemistry and Geological Significance of the Baishan Molybdenum Deposit in the Eastern Tianshan Area,Xinjiang

白山钼矿赋矿岩体为花岗斑岩,其主量、微量及稀土元素地球化学特征研究表明,岩体属过铝质高钾钙碱性系列,并相对富集大离子亲石元素(Rb,Th,Sr等),亏损高场强元素(Nb,Ce,Zr等),以及具有LREE富集的右倾稀土元素分布模式。根据矿物稀土元素作为示踪剂提供的信息表明,含钼矿物的石英脉稀土元素组成和分布模式与壳幔同熔型花岗岩有众多相似之处,推测该成矿物质来源与花岗岩岩浆有关,来自同一源区,形成于碰撞后演化阶段向板内转化的构造环境,并具相同的成岩方式与成岩成矿同期。

Abstract:The deposit's rock mass mainly for the granite porphyry,the major element,trace element and REE geochemistry of the intrusion indicates that:the intrusion belongs to the aluminous high-potassium calc-alkaline series;it is relatively enriched in large ion lithophile elements(Rb,Th,Sr etc.)and depleted in high field strength elements(Nb,Ce,Zr etc.) and exhibits LREE-enriched((La/Yb)N=8.39 to 60.27),right-inclined REE distribution patterns. As the tracer, according to the information of the mineral REE,we found that the compositions and the exhibits of ore-bearing quartz veins are similar to the syntectic granite series. Since granite porphyry is regarded as the late product of granite magma chamber,it maybe inferred that the ore-forming matters are derived mainly from granitic magma. And the deep granite porphyry of the Baishan porphyry molybdenum deposit is an important ore-forming parent rock mass.The ore-bearing quartz veins are from the same source zone and form a tectonic setting that transforms into the plate during the post-collisional evolution stage and have the same diagenesis. Way, diagenesis and mineralization.