青藏高原可可西里地区三叠系巴彦喀拉山群低级-极低级变质作用  

Low-Very Low-Grade Metamorphism of the Hoh Xil Triassic Bayanhar Group on Qinghai-Tibet Plateau

作　　者：袁晏明[1] 桑隆康[1] 李德威[1] 于吉顺[2] 赵继龙[3] 袁宴德 

机构地区：[1]中国地质大学地球科学学院 [2]中国地质大学地质过程与矿产资源国家重点实验室 [3]中国地质大学研究生院,武汉430074 [4]湖南黄金洞矿业有限公司,湖南平江410405

出　　处：《地质科技情报》2008年第3期14-20,共7页Geological Science and Technology Information

基　　金：中国地质调查局项目“不冻泉、库赛湖幅1∶25万区域地质调查”(2003010041)

摘　　要：针对青藏高原可可西里的三叠系巴彦喀拉山群低级—极低级变质岩,利用X射线粉晶衍射分析确定了其矿物的共生组合、伊利石的结晶度Kubler指数(K)和b0值,并根据伊利石结晶度K和b0值对其区域变质作用的温压条件、分带、变质相进行了详细研究,得出了工作区5个不同岩性组合带的变质作用特征:昆仑山脉带属中压浅变质—近变质带,具葡萄石-绿纤石相和绿片岩相;不冻泉—库赛湖带属中压浅变质带,具绿片岩相;楚玛尔河带属中压近变质带,具葡萄石—绿纤石相;直达日旧带属中压浅变质带,具绿片岩相;五道梁带属中压近变质带,具葡萄石-绿纤石相。In the paper, X-ray powder diffraction analysis is used to ascertain the accompanying mineral assemblage, illite crystallinity and b0 value of the Triassic Bayanhar Group low-very low-grade metamorphic rock from Hoh Xil on Qinghai-Tibet Plateau. Moreover, the regional metamorphism, zoning and metamorphic facies of Hoh Xil are studied on the basis of illite crystallinity and b0 value. The study results show that the work area is characterized by five different lithologic associations zones： （1） Kunlun Mountains belt, a middle pressure low-grade metamorphic-anchimetamorphic zone with showing prehnitelotrite facies and green schist facies; （2）Budongquan-Hoh Sai Hu belt, a middle pressure low-grade metamorphic zone of green schist facies; （2）Chumar River belt, a middle pressure anchimetamorphic zone with prehnite-lotrite facies; （4）Zhidarijiu belt, a middle pressure low-grade metamorphic zone of green schist facies; and （5） Wudaoliang belt, a middle pressure anchimetamorphic zone of prehnite-lotrite facies.

关 键 词：青藏高原 巴彦喀拉山群 伊利石结晶度 b0值 极低级变质作用 

分 类 号：P588.34[天文地球—岩石学]