P-T-t-D records of Early Palaeozoic Andean-type shortening of a hot active margin: The Dunhuang block in NW China
文献类型：期刊论文
| 作者 | Soldner, Jérémie5,6; ?típská, Pavla3,4; Schulmann, Karel3,4; Yuan, Chao5,6; Anczkiewicz, Robert2; Jiang, Yingde5,6 ; Koziarska, Marta2; Zhang, Le5,6; Zhang, Yunying1; Wang, Xinyu5,6
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| 刊名 | JOURNAL OF METAMORPHIC GEOLOGY
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| 出版日期 | 2023 |
| 卷号 | 41期号:1页码:59-96 |
| 关键词 | HIGH-PRESSURE GRANULITES ASIAN OROGENIC BELT ZIRCON U-PB HF ISOTOPIC CHARACTERISTICS NORTHEASTERN TARIM CRATON SM-ND GEOCHRONOLOGY LU-HF METAMORPHIC EVOLUTION BOHEMIAN MASSIF TECTONIC IMPLICATIONS |
| ISSN号 | 0263-4929 |
| DOI | 10.1111/jmg.12688 |
| 英文摘要 | High-pressure (HP) granulites form either in the domain of the subducted plate during continental collision or in supra-subduction systems where the thermally softened upper plate is shortened and thickened. Such a discrepancy in tectonic setting can be evaluated by metamorphic pressure–temperature–time-deformation (P–T–t–D) paths. In the current study, P–T–t–D paths of Early Palaeozoic HP granulite facies rocks, in the form of metabasic lenses enclosed in migmatitic metapelite, from the Dunhuang block, NW China, are investigated in order to constrain the nature of the HP rocks and shed light on the geodynamic evolution of a modern hot orogenic system in an active margin setting. The rocks show a polyphase evolution characterized by (1) relics of horizontal or gently dipping fabric (S1) preserved in cores of granulite lenses and in garnet porphyroblasts, (2) a N-S trending sub-vertical fabric (S2) preserved in low-strain domains and (3) upright folds (F3) associated with a ubiquitous steep E-W striking axial planar foliation (S3). Garnet in the granulites preserves relics of a prograde mineral assemblage M1a equilibrated at ~11.5 kbar and ~770–780°C, whereas the matrix granulite assemblage (M1b) from the S1 fabric attained peak pressure at ~13.5 kbar and ~850°C. The granulites were overprinted at ~8–11 kbar and ~850–900°C during crustal melting (M2) followed by partial re-equilibration (M3) at ~8 kbar and ~625°C. A garnet Lu–Hf age of 421.6 ± 1.2 Ma dates metamorphism M1, while a garnet Sm–Nd age of 385.3 ± 4.0 Ma reflects M3 cooling of the granulites. The mineral assemblage, M1, of the host migmatitic metapelite formed at ~9–12.5 kbar and ~760–810°C, partial melting and migmatization (M2) occurred at ~7 kbar and ~760°C and re-equilibration (M3) at ~5–6 kbar and ~675°C. A garnet Lu–Hf age of 409.7 ± 2.3 Ma dates thermal climax (M2) and a garnet Sm–Nd age of 356 ± 11 Ma constrains M3 for the migmatitic metapelites. The timing of this late phase is also bracketed by an emplacement age of syntectonic granite dated at c. 360 Ma. Decoupling of M1 and M2 P–T evolutions between the mafic granulites and migmatitic metapelites indicates their different positions in the crustal column, while the shared pressure–temperature (P–T) evolution M3 suggests formation of a mélange-like association during the late stages of orogeny. The high-pressure event D1-M1 is interpreted as a result of Late Silurian–Early Devonian moderate crustal thickening of a thermally softened and thinned pre-orogenic crust. The high-temperature (HT) re-equilibration D2-M2 is interpreted as a result of Mid-Devonian shortening of the previously thickened crust, possibly due to ‘Andean-type’ underthrusting. The D3-M3 event reflects Late Devonian supra-subduction shortening and continuous erosion of the sub-crustal lithosphere. This tectono-metamorphic sequence of events is explained by polyphased Andean-type deformation of a ‘Cascadia-type’ active margin, which corresponds to a supra-subduction tectonic switching paradigm. ? 2022 John Wiley & Sons Ltd. |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000852195200001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/80290]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 作者单位 | 1.Department of Earth Sciences, The University of Hong Kong, Pokfulam, Hong Kong 2.Institute of Geological Sciences, Polish Academy of Sciences, Kraków, Poland 3.Centre of Lithospheric Research, Czech Geological Survey, Praha, Czech Republic 4.CNRS, ITES, UMR 7063, Université de Strasbourg, Strasbourg, France 5.CAS Center for Excellence in Deep Earth Science, Guangzhou, China 6.State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China |
| 推荐引用方式 GB/T 7714 | Soldner, Jérémie,?típská, Pavla,Schulmann, Karel,et al. P-T-t-D records of Early Palaeozoic Andean-type shortening of a hot active margin: The Dunhuang block in NW China[J]. JOURNAL OF METAMORPHIC GEOLOGY,2023,41(1):59-96. |
| APA | Soldner, Jérémie.,?típská, Pavla.,Schulmann, Karel.,Yuan, Chao.,Anczkiewicz, Robert.,...&Wang, Xinyu.(2023).P-T-t-D records of Early Palaeozoic Andean-type shortening of a hot active margin: The Dunhuang block in NW China.JOURNAL OF METAMORPHIC GEOLOGY,41(1),59-96. |
| MLA | Soldner, Jérémie,et al."P-T-t-D records of Early Palaeozoic Andean-type shortening of a hot active margin: The Dunhuang block in NW China".JOURNAL OF METAMORPHIC GEOLOGY 41.1(2023):59-96. |
入库方式： OAI收割
来源：广州地球化学研究所
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