40Ar-39Ar Geochronology and Tectonic Implications of the Blueschist from Northwestern Qiangtang, Northern Tibet, Western China

被引：9
作者：
Tang Xianchun [1 ,2 ,3 ]
Zhang Kaijun [4 ]
机构：
[1] Chinese Acad Sci, Guangzhou Inst Geochem, Guangzhou 510640, Guangdong, Peoples R China
[2] Chinese Acad Sci, Grad Univ, Beijing 100039, Peoples R China
[3] E China Co, SINOPEC, Res Inst Petr Explorat & Dev, Nanjing 210010, Jiangsu, Peoples R China
[4] Nanjing Univ, Dept Earth Sci, Asian Tecton Res Grp, Nanjing 210093, Jiangsu, Peoples R China
来源：
ACTA GEOLOGICA SINICA-ENGLISH EDITION | 2012年 / 86卷 / 06期
关键词：
blueschist; high-pressure metamorphism; 40Ar-39Ar geochronology; Qiangtang; Tibet; METAMORPHIC BELT; PHASE-EQUILIBRIA; PROVENANCE; ECLOGITES; EVOLUTION; FACIES; SUBDUCTION; PRESSURE; EQUATION; PLATEAU;
D O I：
10.1111/1755-6724.12015
中图分类号：
P [天文学、地球科学];
学科分类号：
07 ;
摘要：
Blueschist exposed in the northwestern Qiangtang terrane, northern Tibet, western China (similar to 84 degrees 30' E, 34 degrees 24' N), provides new constraints on the tectonic evolution of Qiangtang as well as northern Tibet. The blueschist represented by lawsonite- and glaucophane-bearing assemblages equilibrated at 375400 degrees C and similar to 11 kbar. 40Ar-39Ar analysis on mineral separate from one blueschist sample yielded a well-defined plateau age of similar to 242 Ma. Geochemical studies show the blueschist is metamorphosed within-plate basalts. The high pressure-low temperature blueschist indicates a Triassic event of lithosphere subduction, and clearly represents an extension of the central Qiangtang metamorphic belt, and defines an in situ suture between eastern and western Qiangtang.
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收藏
页码：1471 / 1478
页数：8
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