| 东昆仑西大滩混合岩带的基本特征及其成因初探 |
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| ON THE GEOLOGICAL FEATURE AND GENESIS OF THE MIGMATITIC ZONE OF XIDATAN IN EASTERN KUNLUN |
| After Bayan Har terrane came into collision with Kunlun terrane, the Carboniferous and Permian sedimentary rocks have changed to migmatites by migmatization, granitization and remeltization in suture zone which is called the southern marginal fracture in Eastern Kunlun. The time of collision is late Variscan to early Indosinian. According to the data of isotopic age, the migmatites were the products of intra-continental subduction in 170-117Ma (Yanshanian).The migmatitic zone extends E-W and parallels to the suture zone. The migmatites under strongly plastic deformation developed the gneissic, augen structure and various metasomatic textures. The rocks are composed mainly of plagioclase, microcline, quartz and biotite. The porphyroblasts of plagioclase and microcline often suffer shear deformation and the biotites arrange in an orientation paralleling to the main regional structure line. The fact that the potash feldspars are chiefly made of microclines, shows the lower temperature of their formation. With the increasing of SiO2 contant, viz with the increasing degree of migmatization, potassium increases but iron, aluminium magnesium and calcium decrease. The migmatites enriching in aluminium is due to the original rocks containing a lot of clay material.We consider the suture zone of Bayan Har terrane and Kunlun terrane passes through the fracture of Xidatan on the study of migmatitic zone. |
| ZHU Hong,CUI Jun-wen,WU Chang-de,DENG Zong-ce,FENG Xiao-feng.1990.ON THE GEOLOGICAL FEATURE AND GENESIS OF THE MIGMATITIC ZONE OF XIDATAN IN EASTERN KUNLUN[J].Acta Geoscientica Sinica,11(2):77-86. |
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