黑龙江省张广才岭南部早侏罗世花岗岩暗色微粒包体成因研究

发布时间：2018-05-17 14:21

本文选题：张广才岭 + 岩浆混合　；参考：《现代地质》2017年01期

【摘要】：黑龙江省张广才岭南部早侏罗世花岗岩具有明显的岩浆混合特征。岩体中暗色微粒包体发育,主要为细粒闪长质岩浆包体,包体形态多样,与寄主岩呈截然、过渡关系。包体的矿物组合明显不平衡,如矿物具有定向排列的特点,斜长石发育自形环带并存在新、老两个世代,发育针状磷灰石。由电子探针对斜长石、角闪石和黑云母等矿物分析结果可知,寄主花岗岩和包体中各主要矿物含量基本一致。岩石地球化学特征研究显示,包体与寄主花岗岩关系密切,两者在稀土元素和微量元素方面也表现为明显的地球化学亲缘关系。这表明张广才岭南部早侏罗世花岗质岩石具有壳幔混合成因特征,暗色微粒包体是由较基性的地幔岩浆进入寄主岩浆中淬火结晶而成,花岗质岩浆的源区主要为新生的地壳物质。
[Abstract]:The early Jurassic granites in the south of Zhangguangcailing, Heilongjiang Province have obvious magmatic mixing characteristics. The dark particle inclusions in the rock mass are mainly fine-grained diorite magmatic inclusions, which are characterized by a variety of inclusions, which are closely related to the host rocks. The mineral assemblages of the inclusions are obviously unbalanced, such as the directional arrangement of the minerals, the development of the plagioclase with a self-shaped ring belt and the existence of new ones, and the development of needle-like apatite in the old two generations. The results of electron probe analysis of plagioclase, amphibole and biotite show that the contents of major minerals in host granite and inclusions are basically the same. The geochemical characteristics of the rocks show that the xenoliths are closely related to the host granites, and they also show obvious geochemical relationships in the aspects of rare earth elements and trace elements. This indicates that the early Jurassic granitic rocks in the southern part of Zhang Guangcailing have the characteristics of crust and mantle mixing genetic characteristics, and the dark grained inclusions are formed by quenching crystallization from the relatively basic mantle magma entering the host magma. The source of granitic magma is mainly new crustal material.
【作者单位】：中化矿山总局地质研究院;国家行政学院;
【基金】：中国地质调查局项目“黑龙江省1∶5万南蛤拉河子等四幅区域地质矿产调查”(1212011220474)
【分类号】：P588.121

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