Did the Troodos ophiolite of Cyprus form during subduction inception?
文献类型：期刊论文
| 作者 | Ribeiro, Julia2; Macleod, Christopher J.1; Lissenberg, C. Johan1 |
| 刊名 | CHEMICAL GEOLOGY
 |
| 出版日期 | 2023-12-20 |
| 卷号 | 641页码:14 |
| 关键词 | Troodos ophiolite Izu-Bonin-Marianas Southern Mariana fore-arc rifts Subduction initiation Near-trench spreading Slab fluids Supra-subduction zone ophiolites |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2023.121774 |
| 英文摘要 | Understanding whether ophiolites formed during subduction inception or above long-lived subduction zones poses an outstanding challenge as modern examples of incipient subduction zones are rare. It is generally agreed that the Troodos ophiolite of Cyprus was formed at a spreading center above a subduction zone within the closing Neo-Tethys Ocean during the Late Cretaceous; beyond this, however, details of its geodynamic origin have been widely debated. To explore this problem, we examine further the analogy previously made between the Troodos ophiolite and the Mariana fore-arc, by here comparing extrusive rocks from the Troodos ophiolite to Pliocene-aged basalts from the southeastern Mariana fore-arc rifts (SEMFR), which formed by near-trench spreading above a highly dehydrating, mature subducted slab. The SEMFR basaltic glasses and olivine-hosted melt inclusions possess the highest markers of water-rich, slab-fluids (Rb/Th, Cs/Th, H2O/Ce, Ba/Th) of any worldwide arc magmas, a signature that may be consistent with efficient slab dehydration within similar to 90-100 km from the trench. Troodos ophiolite lavas, which have preserved fresh glasses, recorded similar, elevated slab-fluid markers to those of the SEMFR glasses. Although geodynamic comparisons cannot be direct, we nevertheless propose that the chemical similarities in these slab-fluid markers support the formation of the Troodos ophiolite above a highly dehydrating, shallow subducted plate in a near-trench setting. Unlike the southern Marianas, lack of juvenile arc volcanism and associated volcaniclastics, but presence of an extensive boninitic sheeted dyke complex with associated extrusive section, demonstrates that Troodos presumably developed by organized seafloor spreading in a near-trench setting, immediately following subduction inception of the Neo-Tethyan plate. As such, the chemical similarities between the SEMFR magmas and the Troodos ophiolite can only be used to provide constraints upon the geodynamic and the petrogenetic conditions of magma formation. Hence, deciphering precisely the original setting of ophiolites requires us to integrate thoroughly accurate geology and petrographic descriptions, along with comparison with modern analogues of infant subduction zones. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001111238300001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/79149]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Ribeiro, Julia |
| 作者单位 | 1.Cardiff Univ, Sch Earth & Environm Sci, Cardiff CF10 3AT, Wales 2.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Ribeiro, Julia,Macleod, Christopher J.,Lissenberg, C. Johan. Did the Troodos ophiolite of Cyprus form during subduction inception?[J]. CHEMICAL GEOLOGY,2023,641:14. |
| APA | Ribeiro, Julia,Macleod, Christopher J.,&Lissenberg, C. Johan.(2023).Did the Troodos ophiolite of Cyprus form during subduction inception?.CHEMICAL GEOLOGY,641,14. |
| MLA | Ribeiro, Julia,et al."Did the Troodos ophiolite of Cyprus form during subduction inception?".CHEMICAL GEOLOGY 641(2023):14. |
入库方式： OAI收割
来源：广州地球化学研究所
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