西藏中部构造侵蚀与深俯冲:来自安多微大陆逆行榴辉岩发现的证据

IF 3.5 2区 地球科学 Q1 GEOLOGY Journal of Metamorphic Geology Pub Date : 2022-06-28 DOI:10.1111/jmg.12685
Yinbiao Peng, Shengyao Yu, Sanzhong Li, Yongjiang Liu, M. Santosh, Pei Lv, Yunshuai Li, Chuanzhi Li, Yiming Liu
{"title":"西藏中部构造侵蚀与深俯冲:来自安多微大陆逆行榴辉岩发现的证据","authors":"Yinbiao Peng,&nbsp;Shengyao Yu,&nbsp;Sanzhong Li,&nbsp;Yongjiang Liu,&nbsp;M. Santosh,&nbsp;Pei Lv,&nbsp;Yunshuai Li,&nbsp;Chuanzhi Li,&nbsp;Yiming Liu","doi":"10.1111/jmg.12685","DOIUrl":null,"url":null,"abstract":"<p>The Amdo microcontinent which separates the Qiangtang terrane to the north and the Lhasa terrane to the south is a key terrane for reconstructing the tectonic evolution of Central Tibet. We report the new finding of retrograde eclogites within the Amdo microcontinent in this study. The eclogites are characterized by peak metamorphic mineral assemblages of garnet, omphacite, rutile and quartz and underwent a four-stage metamorphic evolution, including a peak eclogite facies stage (M<sub>1</sub>) at ~20–24 kbar and 580–620°C, followed by an HP granulite facies decompression stage (M<sub>2</sub>) at ~13–15 kbar and 750–780°C, a subsequent MP-UHT granulite facies heating stage (M<sub>3</sub>) at 8–10 kbar and &gt;840°C and a final amphibolite facies retrogression (M<sub>4</sub>) at 5.3–6.0 kbar and 560–580°C. The eclogites exhibit rare earth element distribution patterns and trace element abundances similar to those of N-MORB and arc-related volcanics, with depleted whole-rock ε<sub>Nd</sub>(t) values of 3.4 to 4.2, and are inferred to have formed in a back-arc basin tectonic setting. Zircon and rutile U–Pb dating yields a protolith age of 226 ± 5 Ma, a peak eclogite facies metamorphic age of 190 ± 1 Ma, an HP granulite facies metamorphic age of 179 ± 1 Ma and an amphibolite facies retrograde age of 172 ± 1 Ma. The clockwise P–T–t paths and the oceanic protolith signature of retrograde eclogites suggest that part of the back arc basin was subducted to depths of ~80 km. Tectonic erosion associated with the subduction of the Amdo microcontinent beneath the Tethys Ocean accounts for the deep subduction of the back-arc basin and the absence of arc magmatic rocks in the northern Amdo microcontinent.</p>","PeriodicalId":16472,"journal":{"name":"Journal of Metamorphic Geology","volume":null,"pages":null},"PeriodicalIF":3.5000,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Tectonic erosion and deep subduction in Central Tibet: Evidence from the discovery of retrograde eclogites in the Amdo microcontinent\",\"authors\":\"Yinbiao Peng,&nbsp;Shengyao Yu,&nbsp;Sanzhong Li,&nbsp;Yongjiang Liu,&nbsp;M. Santosh,&nbsp;Pei Lv,&nbsp;Yunshuai Li,&nbsp;Chuanzhi Li,&nbsp;Yiming Liu\",\"doi\":\"10.1111/jmg.12685\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The Amdo microcontinent which separates the Qiangtang terrane to the north and the Lhasa terrane to the south is a key terrane for reconstructing the tectonic evolution of Central Tibet. We report the new finding of retrograde eclogites within the Amdo microcontinent in this study. The eclogites are characterized by peak metamorphic mineral assemblages of garnet, omphacite, rutile and quartz and underwent a four-stage metamorphic evolution, including a peak eclogite facies stage (M<sub>1</sub>) at ~20–24 kbar and 580–620°C, followed by an HP granulite facies decompression stage (M<sub>2</sub>) at ~13–15 kbar and 750–780°C, a subsequent MP-UHT granulite facies heating stage (M<sub>3</sub>) at 8–10 kbar and &gt;840°C and a final amphibolite facies retrogression (M<sub>4</sub>) at 5.3–6.0 kbar and 560–580°C. The eclogites exhibit rare earth element distribution patterns and trace element abundances similar to those of N-MORB and arc-related volcanics, with depleted whole-rock ε<sub>Nd</sub>(t) values of 3.4 to 4.2, and are inferred to have formed in a back-arc basin tectonic setting. Zircon and rutile U–Pb dating yields a protolith age of 226 ± 5 Ma, a peak eclogite facies metamorphic age of 190 ± 1 Ma, an HP granulite facies metamorphic age of 179 ± 1 Ma and an amphibolite facies retrograde age of 172 ± 1 Ma. The clockwise P–T–t paths and the oceanic protolith signature of retrograde eclogites suggest that part of the back arc basin was subducted to depths of ~80 km. Tectonic erosion associated with the subduction of the Amdo microcontinent beneath the Tethys Ocean accounts for the deep subduction of the back-arc basin and the absence of arc magmatic rocks in the northern Amdo microcontinent.</p>\",\"PeriodicalId\":16472,\"journal\":{\"name\":\"Journal of Metamorphic Geology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2022-06-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Metamorphic Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1111/jmg.12685\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Metamorphic Geology","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/jmg.12685","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 3

摘要

安多微大陆北隔羌塘地体,南隔拉萨地体,是重建西藏中部构造演化的关键地体。本文报道了在安多微大陆内发现的逆行榴辉岩的新发现。榴辉岩以石榴石、辉长石、金红石和石英的变质峰矿物组合为特征,经历了4期变质演化,包括~20 ~ 24 kbar和580 ~ 620℃的榴辉岩相峰阶段(M1)、~13 ~ 15 kbar和750 ~ 780℃的高压麻粒岩相减压阶段(M2)、8 ~ 10 kbar和>840℃的MP-UHT麻粒岩相加热阶段(M3)和5.3 ~ 6.0 kbar和560 ~ 580℃的角闪岩相退变阶段(M4)。榴辉岩稀土元素分布模式和微量元素丰度与N-MORB和弧缘火山岩相似,全岩亏缺εNd(t)值为3.4 ~ 4.2,形成于弧后盆地构造环境。锆石和金红石U-Pb定年结果表明,原岩年龄为226±5 Ma,榴辉岩相峰变质年龄为190±1 Ma,高压麻粒岩相变质年龄为179±1 Ma,角闪岩相逆变质年龄为172±1 Ma。顺时针P-T-t路径和逆行榴辉岩的海洋原岩特征表明,部分弧后盆地俯冲至~80 km深度。与特提斯洋下安多微大陆俯冲有关的构造侵蚀作用,是导致安多微大陆北部弧后盆地深俯冲和弧后岩浆岩缺失的主要原因。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
Tectonic erosion and deep subduction in Central Tibet: Evidence from the discovery of retrograde eclogites in the Amdo microcontinent

The Amdo microcontinent which separates the Qiangtang terrane to the north and the Lhasa terrane to the south is a key terrane for reconstructing the tectonic evolution of Central Tibet. We report the new finding of retrograde eclogites within the Amdo microcontinent in this study. The eclogites are characterized by peak metamorphic mineral assemblages of garnet, omphacite, rutile and quartz and underwent a four-stage metamorphic evolution, including a peak eclogite facies stage (M1) at ~20–24 kbar and 580–620°C, followed by an HP granulite facies decompression stage (M2) at ~13–15 kbar and 750–780°C, a subsequent MP-UHT granulite facies heating stage (M3) at 8–10 kbar and >840°C and a final amphibolite facies retrogression (M4) at 5.3–6.0 kbar and 560–580°C. The eclogites exhibit rare earth element distribution patterns and trace element abundances similar to those of N-MORB and arc-related volcanics, with depleted whole-rock εNd(t) values of 3.4 to 4.2, and are inferred to have formed in a back-arc basin tectonic setting. Zircon and rutile U–Pb dating yields a protolith age of 226 ± 5 Ma, a peak eclogite facies metamorphic age of 190 ± 1 Ma, an HP granulite facies metamorphic age of 179 ± 1 Ma and an amphibolite facies retrograde age of 172 ± 1 Ma. The clockwise P–T–t paths and the oceanic protolith signature of retrograde eclogites suggest that part of the back arc basin was subducted to depths of ~80 km. Tectonic erosion associated with the subduction of the Amdo microcontinent beneath the Tethys Ocean accounts for the deep subduction of the back-arc basin and the absence of arc magmatic rocks in the northern Amdo microcontinent.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
CiteScore
6.60
自引率
11.80%
发文量
57
审稿时长
6-12 weeks
期刊介绍: The journal, which is published nine times a year, encompasses the entire range of metamorphic studies, from the scale of the individual crystal to that of lithospheric plates, including regional studies of metamorphic terranes, modelling of metamorphic processes, microstructural and deformation studies in relation to metamorphism, geochronology and geochemistry in metamorphic systems, the experimental study of metamorphic reactions, properties of metamorphic minerals and rocks and the economic aspects of metamorphic terranes.
期刊最新文献
Pressure–Temperature–Time Evolution of a Polymetamorphic Paragneiss With Pseudomorphs After Jadeite From the HP–UHP Gneiss‐Eclogite Unit of the Variscan Erzgebirge Crystalline Complex, Germany Issue Information Experimental Replacement of Zircon by Melt‐Mediated Coupled Dissolution‐Precipitation Causes Dispersion in U–Pb Ages Issue Information Kyanite and Cordierite-Andalusite occurrences in parts of Barrow's Staurolite zones – The effects of high ferric iron
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1