Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Wang, Jian1,2,3,4; Wang, Qiang1,2 ; Ma, Lin1,2; Hu, Wan-Long1,2; Wang, Jun1,2; Belousova, Elena3,4,5; Tang, Gong-Jian1,2
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| Rapid Recycling of Subducted Sediments in the Subcontinental Lithospheric Mantle | |
| Source Publication | JOURNAL OF PETROLOGY
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| ISSN | 0022-3530 |
| 2023-08-01 | |
| Volume | 64Issue:8Pages:19 |
| DOI | 10.1093/petrology/egad056 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics |
| Abstract | Subduction recycling of sediments plays a key role in the geochemical evolution of Earth. The presence of recycled terrigenous sediments in upwelling plumes has been cited to explain the EM2 signature in ocean island volcanics, characterized by particularly high Sr-87/Sr-86 (>0.706). However, the origin of such isotopic anomalies in continental regions and the role of subducted sediments in the subcontinental lithospheric mantle (SCLM) remain unclear. The Himalaya-Tibet orogen is one of the world's best places for deciphering continental subduction and the fate of subducted crustal materials in the mantle. Here we present a systematic study of the geochronology, mineral chemistry (especially clinopyroxene), whole-rock chemistry and Sr-Nd-Pb-Hf-O isotopic compositions of Cenozoic potassic-ultrapotassic lavas from the western Kunlun area of northwestern Tibet. New secondary ion mass spectrometry (SIMS) zircon U-Pb dating, coupled with published age results, constrain the timing of volcanism from similar to 8.3 Ma to the present. These lavas show geochemical characteristics that closely resemble the EM2 mantle end-member represented by the Samoan hotspot. Both whole rocks and individual magmatic clinopyroxenes display arc-like trace-element patterns and remarkably enriched Sr-Nd-Pb-Hf isotope compositions (Sr-87/Sr-86 <= 0.7080; epsilon(Nd) <= -4.8; Pb-206/Pb-204 >= 18.704; epsilon(Hf) <=-2.6). Together with high zircon Delta O-18 values (6.3-10.4 & PTSTHOUSND;), the data point to a mantle source enriched by recycled sedimentary materials. Geochemical modeling and geophysical evidence further indicate that the sediments were directly derived from the subducted Indian continental lithosphere during India-Eurasia collision. Partial melting models assuming a hybridized mantle source that contains similar to 5% Indian continental crust suggest that the primary melts of the potassic-ultrapotassic lavas could be formed by melting of a phlogopite-bearing garnet lherzolite at low melting degrees (1-5%). The magma geochemistry is consistent with the model of melange melting, implying that the subducted sediments may detach from the downgoing Indian slab and rise up diapirically into the overlying mantle lithosphere. Unlike traditional models of subducted sediments entering the deep mantle, the western Kunlun EM2-like lavas reveal that subducted sediments can be rapidly recycled into the SCLM during continental subduction (probably <50 Myr). We suggest that the SCLM could be an important reservoir for subducted sediments. The findings are important to our understanding of mantle circulation rates and chemical heterogeneities. |
| Keyword | sediment recycling subcontinental lithospheric mantle continental subduction EM2-like lavas NW Tibet |
| WOS ID | WOS:001052197700001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/74741 |
| Collection | 同位素地球化学国家重点实验室 |
| Corresponding Author | Tang, Gong-Jian |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China 3.Macquarie Univ, ARC Ctr Excellence Core Crust Fluid Syst CCFS, Australian Res Council, Sydney, NSW 2109, Australia 4.Macquarie Univ, Geochem Evolut & Metallogeny Continents GEMOC, Nat Sci, Sydney, NSW 2109, Australia 5.Geol Survey Queensland, Dept Resources, Brisbane, Qld 4000, Australia |
| Recommended Citation GB/T 7714 | Wang, Jian,Wang, Qiang,Ma, Lin,et al. Rapid Recycling of Subducted Sediments in the Subcontinental Lithospheric Mantle[J]. JOURNAL OF PETROLOGY,2023,64(8):19. |
| APA | Wang, Jian.,Wang, Qiang.,Ma, Lin.,Hu, Wan-Long.,Wang, Jun.,...&Tang, Gong-Jian.(2023).Rapid Recycling of Subducted Sediments in the Subcontinental Lithospheric Mantle.JOURNAL OF PETROLOGY,64(8),19. |
| MLA | Wang, Jian,et al."Rapid Recycling of Subducted Sediments in the Subcontinental Lithospheric Mantle".JOURNAL OF PETROLOGY 64.8(2023):19. |
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