中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Formation of an Intracontinental Orogen Above the Permo-Triassic Mantle Convection Cell in the Paleo-Tethys Tectonic Realm due to Far-Field Stress Derived From Continental Margins

文献类型:期刊论文

作者Zhao, Lei1; Zhai, Mingguo1; Zhou, Xiwen2
刊名FRONTIERS IN EARTH SCIENCE
出版日期2022-05-10
卷号10页码:21
关键词retrograded eclogite granulite intraplate orogeny far-field stress south China block
DOI10.3389/feart.2022.892787
英文摘要The identification of intraplate orogens seemingly poses challenges to the plate tectonic theory. Delineating the formation processes of intraplate orogens can provide clues for the better understandings of the above issue. Although still controversial, the Indosinian (Permo-Triassic) orogeny in the South China Block (SCB) is potentially a good example of intracontinental orogen. In this paper, we carry out studies on the Indosinian high-grade rocks in the northeastern Cathaysia Block of the SCB, hoping to cast light on the features and formation processes of intraplate orogenic belts. These rocks exhibit HP/HT granulite facies mineral assemblages and reaction textures imply that they witnessed eclogite-facies metamorphism. Their clockwise P-T trajectories with isothermal decompression stages suggest significant crustal thickening followed by quick orogenic collapse. Immobile whole-rock trace elements indicate basaltic protoliths features, resembling E-MORB and OIB, respectively. SIMS zircon U-Pb age dating confirms Indosinian metamorphic ages of similar to 248 Ma and a protolith age of similar to 953 Ma. The mantle-like O isotopic compositions of the Neoproterozoic magmatic zircon cores further attest that they were primarily mantle derived rocks. The whole-rock Sm-Nd isotopic compositions show more enriched features because of metamorphic alteration, while zircon Lu-Hf isotopic results show primitive characteristics with Neoproterozoic model ages. These features suggest that the high-grade mafic rocks, as well as the metamorphosed early Precambrian metasedimentary rocks hosting them, are all continental crust components and juvenile oceanic crust components featuring plate margins are absent during the SCB Indosinian orogeny. Characteristics of these high-grade rocks and their spatial occurrences are both consistent with the proposal of an intracontinental orogen. After summarizations and comparisons of the Indosinian plate margin activities around the SCB, we suggest that this northeast-southwest trending orogenic belt is geometrically consistent with two mantle convection cells, with one conveying the SCB northward to collide with the North China Craton, and the other conveying the Paleo-Pacific plate northwestwards to form an active continental margin along the southeast SCB. The driving mechanism of the formation of the SCB Indosinian intracontinental orogenic belt could have broad implications for other intraplate orogens around the world.
WOS关键词MESOZOIC OVERTHRUST TECTONICS ; WILSON CYCLE MODEL ; U-PB GEOCHRONOLOGY ; BEARING EPIDOTE-AMPHIBOLITE ; SOUTH CHINA CONSTRAINTS ; A-TYPE GRANITES ; ND-HF ISOTOPES ; CATHAYSIA BLOCK ; LU-HF ; JIANGNAN OROGEN
WOS研究方向Geology
语种英语
WOS记录号WOS:000802265300001
出版者FRONTIERS MEDIA SA
源URL[http://ir.iggcas.ac.cn/handle/132A11/106036]  
专题地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者Zhao, Lei
作者单位1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing, Peoples R China
2.Chinese Acad Geol Sci, Inst Geol, Beijing, Peoples R China
推荐引用方式
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Zhao, Lei,Zhai, Mingguo,Zhou, Xiwen. Formation of an Intracontinental Orogen Above the Permo-Triassic Mantle Convection Cell in the Paleo-Tethys Tectonic Realm due to Far-Field Stress Derived From Continental Margins[J]. FRONTIERS IN EARTH SCIENCE,2022,10:21.
APA Zhao, Lei,Zhai, Mingguo,&Zhou, Xiwen.(2022).Formation of an Intracontinental Orogen Above the Permo-Triassic Mantle Convection Cell in the Paleo-Tethys Tectonic Realm due to Far-Field Stress Derived From Continental Margins.FRONTIERS IN EARTH SCIENCE,10,21.
MLA Zhao, Lei,et al."Formation of an Intracontinental Orogen Above the Permo-Triassic Mantle Convection Cell in the Paleo-Tethys Tectonic Realm due to Far-Field Stress Derived From Continental Margins".FRONTIERS IN EARTH SCIENCE 10(2022):21.

入库方式: OAI收割

来源:地质与地球物理研究所

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