Timing and duration of discrete tectono-metamorphic events of the polymetamorphic high-grade Central zone of the Limpopo Belt (South Africa): Insight from in situ geochronology of monazite and zircon
文献类型：期刊论文
| 作者 | Zhou, Tian1,2,3,4; Klemd, Reiner4; Brandt, Soenke4; Liu, Yu2,3; Li, Qiu-Li1,2,3 |
| 刊名 | PRECAMBRIAN RESEARCH
 |
| 出版日期 | 2022 |
| 卷号 | 368页码:20 |
| 关键词 | Polymetamorphism Duration of metamorphic events Secondary ion mass spectrometry U-Pb dating Monazite Zircon Limpopo Belt |
| ISSN号 | 0301-9268 |
| DOI | 10.1016/j.precamres.2021.106469 |
| 英文摘要 | The Central Zone of the Limpopo Belt in southern Africa is a complex polymetamorphic terrane that has expe-rienced three metamorphic events, at 3.22 Ga (M1), 2.71-2.56 Ga (M-2) and 2.02 Ga (M3). On the basis of a previous detailed petrological and geothermobarometrical study of a newly discovered supracrustal enclave within the Bulai Pluton (ca. 2.61 Ga granitoid gneiss in the Central Zone), we conducted a geochronological in situ study of texturally and chemically different monazite and zircon grains, which occur respectively as in-clusions in garnet, in decompressional cordierite coronas around garnet and as matrix grains in polymetamorphic granulite-facies metapelites. Secondary-ion mass spectrometry (SIMS) in situ analyses of the monazite and zircon grains in thin sections, complemented by analyses of separated zircon grains, allowed the texturally-controlled direct determination of U-Pb and( 207)Pb/Pb-206 ages at a scale of < 10 mu m. A concordant age of ca. 2.71 Ga derived from zircon included in garnet is interpreted to reflect the age of initial garnet growth during the pro-grade M2 metamorphism. Zircons in the cordierite coronas around garnet revealed a slightly younger concordant age of ca. 2.56 Ga. Zircon growth in the coronas is related to the retrograde breakdown of garnet (Zr-bearing) through to the decompression reaction garnet + sillimanite + quartz & RARR; cordierite + zircon and hence the ca. 2.56 Ga zircon age is interpreted to reflect the timing of post-peak decompressional uplift. The zircon ages constrain the duration of M2 metamorphism to approximately 145 Myr. A concordant 2.71 Ga age of large monazite inclusions in garnet cores corroborates the 2.71 Ga zircon age of initial garnet growth during the prograde M(2 )metamorphism. Core domains of the largest monazite in cordierite corona revealed ages between 2.5 and 2.0 Ga that are interpreted to reflect (multiple) Pb-loss during the M-3 granulite-facies metamorphism. Other monazites in cordierite coronas and matrix showed an age of ca. 2.0 Ga, reflecting complete re-equilibration or new growth during M3 overprinting. Owing to the preservation of the original micro-textures related to the growth of zircon and monazite we were able to link the age data with the P-T record, and refine the timing and duration of the M2 granulite-facies metamorphism (approximately 2.71-2.56 Ga) in the Limpopo Belt that was previously dated at ca. 2.62 Ga by zircon separation techniques. The ca. 145 Ma duration of granulite-facies metamorphism is consistent with a tectonic model of long-lasting asthenosphere upwelling and subsequent continent-continent collision in the late Neoarchean. Decompression triggered by post-collisional extension occurred at 2.56 Ga. Paleoproterozoic M3 granulite-facies metamorphism at ca. 2.0 Ga caused the widespread re-setting of the U-Pb and Pb-Pb data that also affected most zircon and monazite grains. This study reveals that precise dating of the timing and duration of distinct tectono-metamorphic events by texturally-controlled in situ geochronology allows a much better insight into the complex geodynamic evolution of high-grade polymetamorphic terranes. |
| WOS关键词 | NATURAL REFERENCE MATERIAL ; VENETIA KIMBERLITE PIPES ; P-T PATHS ; SIMS U-PB ; FIELD RELATIONSHIPS ; GRANITOID GNEISSES ; BRIDGE COMPLEX ; SHEAR ZONES ; MOBILE BELT ; EVOLUTION |
| 资助项目 | National Key Research and Development Program of China[2016YFE0203000] ; National Natural Science Foundation of China[41773044] ; National Program for Support of Top-notch Young Professionals |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000806634400002 |
| 出版者 | ELSEVIER |
| 资助机构 | National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals ; National Program for Support of Top-notch Young Professionals |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/106058]  |
| 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 | Li, Qiu-Li |
| 作者单位 | 1.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing 100029, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 4.Friedrich Alexander Univ Erlangen Nurnberg, Schlossgarten 5a, D-91054 Erlangen, Germany |
| 推荐引用方式 GB/T 7714 | Zhou, Tian,Klemd, Reiner,Brandt, Soenke,et al. Timing and duration of discrete tectono-metamorphic events of the polymetamorphic high-grade Central zone of the Limpopo Belt (South Africa): Insight from in situ geochronology of monazite and zircon[J]. PRECAMBRIAN RESEARCH,2022,368:20. |
| APA | Zhou, Tian,Klemd, Reiner,Brandt, Soenke,Liu, Yu,&Li, Qiu-Li.(2022).Timing and duration of discrete tectono-metamorphic events of the polymetamorphic high-grade Central zone of the Limpopo Belt (South Africa): Insight from in situ geochronology of monazite and zircon.PRECAMBRIAN RESEARCH,368,20. |
| MLA | Zhou, Tian,et al."Timing and duration of discrete tectono-metamorphic events of the polymetamorphic high-grade Central zone of the Limpopo Belt (South Africa): Insight from in situ geochronology of monazite and zircon".PRECAMBRIAN RESEARCH 368(2022):20. |
入库方式： OAI收割
来源：地质与地球物理研究所
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