鄂西南双河渔塘坝硒矿区硅质岩地球化学特征

THE GEOCHEMISTRY OF CHERT FROM YUTANGBA SELENIUM DIGGING IN SHUANGHE, HUBEI PROVINCE

双河渔塘坝硒矿位于扬子准地台、上扬子台褶带的北部 ,受双河向斜构造控制。本区硅质岩的稀土元素特征表明 :稀土总量低 ,其平均值为 38.945× 10 -6,富集轻稀土元素 ,呈现负的Ce异常和正的Eu异常 ,表现出一定的热水成因的属性。说明本区含硒的硅质岩主要形成于浅海滞留盆地、缺氧的还原环境 ,是属于热水成因的一类硅质岩。

This digging is located in upper Yangtze fold belt of north of Yangtze platform and controlled by Shuanghe syncline. The content of REE of chert are low, average aboudance is 38.945×10 -6 . Comparative speaking, it is rich in LREE and has Ce negative anomaly and Eu positive anomaly. All the evidences show a character of hot water genesis. It is suggested that the Se bearing chert in this region was formed in arrested basin of shallow sea, under a reduction environment.