Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Tang, Guo-Rong1,2; Dan, Wei1 ; Maulana, Adi3; Wang, Jian1; Zhang, Xiu-Zheng1; Zhang, Yun-Ying4; Ma, Xin1,2; Wang, Qiang1,2; Liu, Xi -Jun5; Tang, Gong-Jian1
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| Arc building and maturation of the Lombok Island, East Sunda Arc | |
| Source Publication | CHEMICAL GEOLOGY
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| ISSN | 0009-2541 |
| 2024-09-20 | |
| Volume | 663Pages:15 |
| DOI | 10.1016/j.chemgeo.2024.122265 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics |
| Abstract | Intra-oceanic subduction zones are major sites of crust-mantle material exchange and crustal growth; however, the processes responsible for the magmatic evolution and transformation of nascent arcs into mature oceanic arcs with thicker crust are debated. We present mineral chemistry, zircon U-Pb age and Hf isotopic data, and wholerock chemical and Sr-Nd-Hf-Pb isotopic data for Cenozoic volcanic rocks on Lombok in the East Sunda Arc, Indonesia, to investigate their petrogenesis and arc maturation. SIMS zircon U-Pb analyses of lavas from southern Lombok yield an early Oligocene age of similar to 30 Ma. The lavas can be divided into three groups based on their ages and geochemical characteristics: group I (late Eocene) and II (similar to 30 Ma) lavas from southern Lombok, and group III lavas (similar to 3-0 Ma) from northern Lombok. The lavas are characterized by a progressive enrichment in K2O and incompatible element contents, and Nd-Hf isotopic compositions with time. Group I lavas are tholeiitic basalts with low K2O contents (0.15-0.17 wt%) and Indian-MORB like rare earth element (REE) patterns and Nd-Hf isotopic compositions (epsilon(Nd) = +7.4; epsilon(Hf) = +14.5), enrichment in large-ion lithophile elements (e.g., Rb, U, and K), and typical forearc basalt (FAB) geochemical characteristics. Group II lavas are low-K basaltic andesites to dacites that yield flat chondrite-normalized REE patterns [(La/Sm)(N) = 0.9-1.4], uniform initial Sr-87/Sr-86 ratios (0.7038-0.7042), and positive epsilon(Nd)(t) ( +5.9 to +6.8) and epsilon(Hf)(t) (+13.9 to +14.4) values. Group III lavas are typically medium- to high-K calc-alkaline basalt to andesite and are enriched in light REEs [(La/Sm)(N) = 1.6-3.3] with uniform initial Sr-87/Sr-86 ratios (0.7038-0.7042) and slightly low epsilon(Nd)(t) ( +3.9 to +5.4) and epsilon(Hf)(t) (+10.5 to +12.5) values. Progressive enrichment in incompatible element contents and Nd-Hf isotopic compositions over time, from FAB to high-K calc-alkaline lavas, reflect the maturation of the East Sunda Arc. Sr-Nd-Pb-Hf isotopic mixing models, along with trace element ratios (e.g., Ba/Th, La/Yb, Th/Yb), suggest that increasing amounts of sediments were incorporated into the mantle sources of the magmas from group I (similar to 0%) to group II (<0.5%) and group III (0.5%-1.0%) lavas. Partial melting models show that the formation of group I and II lavas can be reproduced by high-degree (similar to 10%) partial melting of spinel peridotite, whereas the group III lavas were formed by low-degree (similar to 5%) partial melting of spinel peridotite. We propose that the evolution of Lombok arc magmas was controlled mainly by the fluxes of subducted slab material, along with decreasing degrees of partial melting as a result of crustal thickening over time. |
| Keyword | Basalt Intra-oceanic arc Sr-Nd-Pb-Hf isotopes Arc maturation Volcanic rock Lombok Island Sunda Arc |
| WOS ID | WOS:001272704800001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/72358 |
| 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.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 3.Hasanuddin Univ, Dept Geol, Jl Perintis Kemerdekaan KM 10, Makassar 90245, Indonesia 4.Chinese Acad Sci, South China Sea Inst Oceanol, Key Lab Ocean & Marginal Sea Geol, Guangzhou 510301, Peoples R China 5.Guilin Univ Technol, Coll Earth Sci, Guangxi Key Lab Explorat Hidden Met Ore Deposits, Guilin 541006, Peoples R China |
| Recommended Citation GB/T 7714 | Tang, Guo-Rong,Dan, Wei,Maulana, Adi,et al. Arc building and maturation of the Lombok Island, East Sunda Arc[J]. CHEMICAL GEOLOGY,2024,663:15. |
| APA | Tang, Guo-Rong.,Dan, Wei.,Maulana, Adi.,Wang, Jian.,Zhang, Xiu-Zheng.,...&Tang, Gong-Jian.(2024).Arc building and maturation of the Lombok Island, East Sunda Arc.CHEMICAL GEOLOGY,663,15. |
| MLA | Tang, Guo-Rong,et al."Arc building and maturation of the Lombok Island, East Sunda Arc".CHEMICAL GEOLOGY 663(2024):15. |
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