Recycled lower oceanic crust signal in early Jurassic A1 1-type granites, South China: Implications for flat-slab subduction and mantle heterogeneity in the continental back-arc region
文献类型：期刊论文
| 作者 | Yan, Bo1,2; Li, Wu-Xian1; Huang, Xiao-Long1; Tao, Ji-Hua3,4 |
| 刊名 | CHEMICAL GEOLOGY
 |
| 出版日期 | 2024-08-20 |
| 卷号 | 660页码:18 |
| 关键词 | A-type granite Early Jurassic Flat-slab subduction South China |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2024.122155 |
| 英文摘要 | Flat-slab subduction is a distinctive phenomenon that leads to the development of a wide orogenic zone (>= 800 km) along former continental margins, triggering extensive intraplate magmatism and deformation. However, occurrences of flat-slab subduction on ancient convergent margins are exceptionally rare, possibly owing to multiple episodes of structural destruction and/or poor preservation. Furthermore, the impact of flat-slab subduction on mantle heterogeneity remains ambiguous. In this study, we present comprehensive whole-rock geochemical analyses as well as in-situ zircon U-Pb - Pb dating and Hf-O - O isotopic data for Early Jurassic A-type granites from the Pitou and Shibixia plutons in the interior of the South China Block to investigate the potential influence of flat-slab subduction on intraplate magmatism. The Pitou granites exhibit characteristics consistent with those of A2 2-type granite, displaying zircon epsilon Hf(t) Hf (t) values ranging from-4.9 to +0.3 and elevated delta 18O 18 O values of 6.2-7.6%o. %o . These features suggest that the granites formed through the differentiation of a basaltic parental magma, which underwent varying degrees of crustal contamination. In contrast, the Shibixia granites show A1 1type geochemical features and were derived from basaltic parental magma without significant crustal contamination. The zircons in these granites exhibit positive epsilon Hf(t) Hf (t) values ranging from +6.6 to +10.6 and anomalously low delta 18O 18 O values of 3.3-4.0%o, %o , suggesting the involvement of recycled altered lower oceanic crust components in their mantle source. This provides strong evidence for the occurrence of flat-slab subduction beneath the interior of the South China Block during the early Mesozoic, which was located at least 800 km away from the trench. Combined with the presence of post-delamination ocean island-like intraplate magmatic rocks in the South China interior, it is suggested that the flat-slab delamination at approximately 190 Ma facilitated late Mesozoic intraplate OIB-like magmatism. This process, associated with flat-slab subduction, is expected to exert a significant impact on mantle isotopic heterogeneity within continental back-arc regions. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001333620300001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/81224]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Li, Wu-Xian |
| 作者单位 | 1.Chinese Acad Sci, CAS Ctr Excellence Deep Earth Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 3.East China Univ Technol, Sch Earth Sci, Nanchang 330013, Peoples R China 4.East China Univ Technol, Natl Key Lab Prospecting Min & Remote Sense Detect, Nanchang 330013, Peoples R China |
| 推荐引用方式 GB/T 7714 | Yan, Bo,Li, Wu-Xian,Huang, Xiao-Long,et al. Recycled lower oceanic crust signal in early Jurassic A1 1-type granites, South China: Implications for flat-slab subduction and mantle heterogeneity in the continental back-arc region[J]. CHEMICAL GEOLOGY,2024,660:18. |
| APA | Yan, Bo,Li, Wu-Xian,Huang, Xiao-Long,&Tao, Ji-Hua.(2024).Recycled lower oceanic crust signal in early Jurassic A1 1-type granites, South China: Implications for flat-slab subduction and mantle heterogeneity in the continental back-arc region.CHEMICAL GEOLOGY,660,18. |
| MLA | Yan, Bo,et al."Recycled lower oceanic crust signal in early Jurassic A1 1-type granites, South China: Implications for flat-slab subduction and mantle heterogeneity in the continental back-arc region".CHEMICAL GEOLOGY 660(2024):18. |
入库方式： OAI收割
来源：广州地球化学研究所
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