甘肃省礼县中川岩体特征研究

Study on Characteristics of Zhongchuan Intrusive in Lixian of Gansu

甘肃省礼县中川岩体位于中秦岭华力西期褶皱系礼县—柞水冒地槽褶皱带西段中部,岩性主要为黑云母花岗岩,岩石化学分析结果表明属于碱性系列,具高硅、过铝、富碱和贫钙、镁、铁等特征,主要造岩矿物和微量元素含量均一,反映其分异作用不强。K-Ar全岩法测年结果为181-229百万年,说明岩体形成于印支期晚期,形成环境为大洋—大陆汇聚环境。

Zhongchuan intrusiveis located in the middle section of the west geosyncline fold belt in Lixian-Zhashui within the Hercynian fold system in the middle Qinling,and the main rocks is biotite granite.According to bulk compositions,these rocks belong to alkaling igneous protoliths with high Si,over-saturated aluminum,characterized by the enrichment of alkaline and low Ca,Fe and Mg contents.The contents of the main rock-forming minerals and the traceelements is almost the same,it reflects that the magmatic differentiations of the intrusiveis is not strong.These rocks formed in the late indosinian based on the data which is from 181-229Ma of K-Ar dating of the samples from the intrusive.It formation environment is ocean-continent convergence environment.