喜马拉雅东构造结高压麻粒岩PT轨迹、锆石U-Pb定年及其地质意义

CORC > 北京大学 > 地球与空间科学学院

	喜马拉雅东构造结高压麻粒岩PT轨迹、锆石U-Pb定年及其地质意义; High-pressure granulites from Eastern Himalayan Syntaxis P-T, path, zircon U-Pb dating and geological implications
	刘凤麟 ; 张立飞
刊名	岩石学报
	2014
关键词	高压麻粒岩 PT轨迹锆石U-Pb定年喜马拉雅东构造结青藏高原隆升 High-pressure granulites P-T path Zircon U-Pb dating Eastern Himalayan Syntaxis Tibetan Plateau
英文摘要	喜马拉雅东构造结出露了一套基性高压麻粒岩,其峰期矿物组合为石榴石+单斜辉石+石英+金红石+斜长石,利用相平衡计算其峰期温压条件为904℃、1.37GPa,利用锆石U-Pb定年方法确定其变质年龄为20.7±2.3Ma。角闪斜方辉石麻粒岩为其第一阶段退变产物,其变质矿物组合为斜方辉石+角闪石+斜长石+石英+钛铁矿+磁铁矿,温压条件为压力小于0.6GPa,温度为720~760℃。角闪岩相退变矿物组合为角闪石+斜长石+石英+钛铁矿+磁铁矿,温度小于745℃,压力小于0.6GPa。在角闪斜方辉石麻粒岩中变质锆石获得的定年结果为9.38±0.22M,根据锆石中角闪石+斜长石+石英的矿物包体特征,确定该年龄...; Along Yalu-Tsangpo River, Eastern Himalayan Syntaxis, expose high-pressure mafic granulites. Peak stage assemblage of high-pressure mafic granulite is' garnet + clinopyroxene + quartz + rutile. The reaction plagioclase + orthopyroxene -> clinopyroxene + garnet + quartz indicates peak pressure exceeded the orthopyroxene-out pressure. The peak conditions of high-pressure mafic granulite are 904 degrees C and 1.37GPa. Ziircon U-Pb dating shows that the age of high pressure granulite facies metamorphism is 20.7 +/- 2.3Ma. Amphibole-orthopyroxene granulite is the product of the first stage retrograde metamorphism, and the assemblage is orthopyroxene amphibole + plagioclase + quartz + ilmenite + magnetite, and the P-T conditions are < 0.6GPa and 720 similar to 760 degrees. The overprinted amphibolite facies assemblage is amphibole + plagioclase + quartz + ilmenite + magnetite and the P-T conditions are <0.6GPa and, <745 degrees C. The age of metamorphic zircon in amphibole-orthopyroxene granulite is 9.38 +/- 0.22Ma, According to the inclusions amp + pl. + qz.in. such zircon, this age represents the age of,amphibolite facies metamorphism. Therefore, the PT-t path of the high,pressure granulites from Eastern Himalayan Syntaxis is clockwise and it represents a two-stage exhumation process, i.e.. the first stage of exhumation: from the depth of high-pressure granulite facies to the depth of amphibolite facies beginning at about 20Ma;. the second stage-of exhumation: from the depth of amphibolite facies to the earth surface beginning at about 9Ma. According the P-T conditions and the results of U-Pb zircon dating, the average exhumation rates for these two stage's are 2.4mm/y and 2.3mm/y respectively. Our study is consistent with the opinion of two-stage uplifts of Tibetan Plateau and further proves that the uplift of Tibetan Plateau connects tightly with the exhumation; of subduction zone.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000344215200002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 2; lfzhang@pku.edu.cn; 10; 2808-2820; 30
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/310934]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	刘凤麟,张立飞. 喜马拉雅东构造结高压麻粒岩PT轨迹、锆石U-Pb定年及其地质意义, High-pressure granulites from Eastern Himalayan Syntaxis P-T, path, zircon U-Pb dating and geological implications[J]. 岩石学报,2014.
APA	刘凤麟,&张立飞.(2014).喜马拉雅东构造结高压麻粒岩PT轨迹、锆石U-Pb定年及其地质意义.岩石学报.
MLA	刘凤麟,et al."喜马拉雅东构造结高压麻粒岩PT轨迹、锆石U-Pb定年及其地质意义".岩石学报 (2014).