Zircon U-Pb Geochronology and Geochemistry and Their Geological Significances of Eclogites from East Kunlun High-Pressure Metamorphic Belt

被引：1
|
作者：
Guo X. [1 ,2 ]
Jia Q. [2 ]
Li J. [2 ]
Kong H. [2 ]
Yao X. [1 ,2 ]
Mi J. [2 ]
Qian B. [2 ]
Wang Y. [2 ]
机构：
[1] Geological Survey Insitute, China University of Geosciences, Wuhan
[2] Xi'an Center of Geological Survey, Orogen Research Center, China Geological Survey, Xi'an
来源：
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | 2018年 / 43卷 / 12期
关键词：
East Kunlun; Eclogite; Geochemistry; Geochronology; High-pressure metamorphic belt;
D O I：
10.3799/dqkx.2018.142
中图分类号：
学科分类号：
摘要：
Eclogites have been recognized in areas of Xiarihamu-Suhaitu, Dagele, Zongjia, Garidang(the upper reach of Langmuri), Jiadang, and Wenquan, respectively, in East Kunlun orogenic belt. The eclogites in various sizes occur in Jinshuikou metamorphic rocks and different terranes of eclogites constitute the East Kunlun high pressure metamorphic belt with a length of more than 530 km. This paper presents a research on the petrology, geochemistry and isotope chronology of the eclogites. The results show that eclogite types are complex which can be further divided into eclogites, retrograded eclogites and amphibole-eclogites. The eclogite geochemical analyses show that SiO2 contents range from 41.58% to 59.00% with an average of 50.19%; Al2O3 contents range from 11.27% to 18.54% with an average of 14.66%; TiO2 contents range from 0.76% to 1.59% with an average of 1.03%; REE distribution patterns mainly show enrichment in LREE and the trace element distribution patterns show the characteristics between the E-MORB and N-MORB. 440±13 Ma metamorphism age and 934±15 Ma original age of amphibole-eclogites in Jiadang were obtained. And the histogram of eclogite zircon age shows a variety of information including three peak ages of the metamorphic ages at 451 Ma, 432 Ma and 412 Ma respectively, one peak age of the original rock age at 936 Ma, 515-440 Ma records the subduction of the magma thermal event, 440-420 Ma recording subduction and collision of high pressure metamorphic and 420-390 Ma as a reflection of eclogite degradation. It is concluded that the metamorphic age of eclogite is closely related to the tectonic evolution of East Kunlun. © 2018, Editorial Department of Earth Science. All right reserved.
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页码：4300 / 4318
页数：18
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