Subduction initiation-induced rapid emplacement of garnet-bearing peridotites at a nascent forearc: Petrological and Os-Li isotopic evidence from the Purang ophiolite, Tibet
文献类型：期刊论文
| 作者 | Gong, Xiao-Han1; Xu, Ji-Feng2; Shi, Ren-Deng3,4; Su, Ben-Xun5; Huang, Qi-Shuai3; Huang, Xiao-Xiao6 |
| 刊名 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
 |
| 出版日期 | 2022-03-01 |
| 卷号 | 134期号:3-4页码:722-738 |
| ISSN号 | 0016-7606 |
| DOI | 10.1130/B35960.1 |
| 英文摘要 | Garnet-bearing peridotites commonly occur in the deeper parts of mature or thickened oceanic lithosphere, and are rarely exhumed and emplaced onto the seafloor. The Purang ophiolitic peridotites in south Tibet contain rare symplectite pseudomorphs after garnet, offering a unique window into the still poorly understood evolution of the deep oceanic lithosphere. Here, integrated petrologic and Os-Li isotopic data are used to constrain the evolution and dynamics of emplacement for these garnet peridotite protoliths. The Purang peridotites show wide variations of chemical compositions (spinel Cr#: 0.2-0.8) and Os model ages (up to 2.0 Ga), thus representing a piece of heterogeneous oceanic mantle lithosphere. Dunite channels show two distinctive groups of Cr# of spinels and Os-isotope compositions, with the low-to medium-Cr# (0.2-0.6) and high-Cr# (0.7-0.8) dunites reflecting the reaction of host lherzolites/harzburgites with percolating mid-ocean ridge basalt-like and boninitic melts, respectively. This confirms recent subduction initiation-related melt percolation in the Purang peridotites. Coexisting olivines and pyroxenes in the peridotites show systematic Li elemental and isotopic disequilibrium, suggesting fast cooling of the peridotites to Li closure temperature shortly after the melt percolations, likely during exhumation of the peridotites onto the seafloor. This supports a close link between subduction initiation and tectonic emplacement of the Purang peridotites. Combined with other geological evidence, we suggest the Purang peridotites may originate from the deep part of old, thick oceanic lithosphere of the NeoTethys. This thick oceanic lithosphere was progressively weakened and thinned likely during widespread plume-lithosphere interaction, triggering the transformation of garnet peridotite protoliths to spinel peridotites. Subsequently, initiation of a new subduction zone along the lithospheric weakness caused rapid ascent and emplacement of the Purang peridotites at a nascent forearc. |
| WOS关键词 | IZU-BONIN-MARIANA ; YARLUNG-ZANGBO SUTURE ; MELT-ROCK INTERACTION ; PLASMA-MASS SPECTROMETRY ; SUPRA-SUBDUCTION ; OCEANIC LITHOSPHERE ; MANTLE XENOLITHS ; SOUTHERN TIBET ; LUOBUSA OPHIOLITE ; XIGAZE OPHIOLITE |
| 资助项目 | National Key Research and Development Project of China[2020YFA0714800] ; National Natural Science Foundation of China[41802046] ; Second Tibetan Plateau Scientific Expedition and Research Program[STEP 2019QZKK0801] ; Ministry of Science and Technology, China[BP0719021] |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000764822800002 |
| 出版者 | GEOLOGICAL SOC AMER, INC |
| 资助机构 | National Key Research and Development Project of China ; National Key Research and Development Project of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Second Tibetan Plateau Scientific Expedition and Research Program ; Second Tibetan Plateau Scientific Expedition and Research Program ; Ministry of Science and Technology, China ; Ministry of Science and Technology, China ; National Key Research and Development Project of China ; National Key Research and Development Project of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Second Tibetan Plateau Scientific Expedition and Research Program ; Second Tibetan Plateau Scientific Expedition and Research Program ; Ministry of Science and Technology, China ; Ministry of Science and Technology, China ; National Key Research and Development Project of China ; National Key Research and Development Project of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Second Tibetan Plateau Scientific Expedition and Research Program ; Second Tibetan Plateau Scientific Expedition and Research Program ; Ministry of Science and Technology, China ; Ministry of Science and Technology, China ; National Key Research and Development Project of China ; National Key Research and Development Project of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Second Tibetan Plateau Scientific Expedition and Research Program ; Second Tibetan Plateau Scientific Expedition and Research Program ; Ministry of Science and Technology, China ; Ministry of Science and Technology, China |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/105006]  |
| 专题 | 地质与地球物理研究所_中国科学院矿产资源研究重点实验室 |
| 通讯作者 | Xu, Ji-Feng; Shi, Ren-Deng |
| 作者单位 | 1.China Univ Geosci, Sch Ocean Sci, Beijing 100083, Peoples R China 2.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing, Peoples R China 3.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100101, Peoples R China 4.Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 5.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China 6.North China Univ Water Resources & Elect Power, Coll Geosci & Engn, Zhengzhou, Peoples R China |
| 推荐引用方式 GB/T 7714 | Gong, Xiao-Han,Xu, Ji-Feng,Shi, Ren-Deng,et al. Subduction initiation-induced rapid emplacement of garnet-bearing peridotites at a nascent forearc: Petrological and Os-Li isotopic evidence from the Purang ophiolite, Tibet[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2022,134(3-4):722-738. |
| APA | Gong, Xiao-Han,Xu, Ji-Feng,Shi, Ren-Deng,Su, Ben-Xun,Huang, Qi-Shuai,&Huang, Xiao-Xiao.(2022).Subduction initiation-induced rapid emplacement of garnet-bearing peridotites at a nascent forearc: Petrological and Os-Li isotopic evidence from the Purang ophiolite, Tibet.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,134(3-4),722-738. |
| MLA | Gong, Xiao-Han,et al."Subduction initiation-induced rapid emplacement of garnet-bearing peridotites at a nascent forearc: Petrological and Os-Li isotopic evidence from the Purang ophiolite, Tibet".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 134.3-4(2022):722-738. |
入库方式： OAI收割
来源：地质与地球物理研究所
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