| 118-115 Ma magmatism in the Tethyan Himalaya igneous province: Constraints on Early Cretaceous rifting of the northern margin of Greater India | |
| Chen, SS (Chen, Sheng-Sheng)1,2; Fan, WM (Fan, Wei-Ming)1,2,3; Shi, RD (Shi, Ren-Deng)1,2; Liu, XH (Liu, Xiao-Han)2; Zhou, XJ (Zhou, Xue-Jun)2 | |
| Source Publication | EARTH AND PLANETARY SCIENCE LETTERS
 |
| 2018-06-01 | |
| Volume | 491Issue:0Pages:21-33 |
| DOI | 10.1016/j.epsl.2018.03.034 |
| Abstract | Understanding the dynamics of Large Igneous Provinces (LIPs) is critical to deciphering processes associated with rupturing continental lithosphere. Microcontinental calving, the rifting of microcontinents from mature continental rifted margins, is particularly poorly understood. Here we present new insights into these processes from geochronological and geochemical analyses of igneous rocks from the Tethyan Himalaya. Early Cretaceous mafic dikes are widely exposed in the eastern and western Tethyan Himalaya, but no such rocks have been reported from the central Tethyan Himalaya. Here we present an analysis of petrological, geochronological, geochemical, and Sr-Nd-Hf-Os isotopic data for bimodal magmatic rocks from the center-east Tethyan Himalaya. Zircon U-Pb dating yields six weighted-mean concordant Pb-206/U-238 ages of 118 +/- 1.2 to 115 +/- 1.3 Ma. Mafic rocks display MORB-like compositions with flat to depleted LREE trends, and positive epsilon(Nd)(t) (+2.76 to +5.39) and epsilon(Hf)(t) (+8.0 to +11.9) values. The negative Nb anomalies and relatively high Os-187/Os-188 ratios (0.15-0.19) of these rocks are related to variable degrees (up to 10%) of crustal contamination. Geochemical characteristics indicate that mafic rocks were generated by variable degrees (2-20%) of partial melting of spinel lherzolites in shallow depleted mantle. Felsic rocks are enriched in Th and LREE, with negative Nb anomalies and decoupling of Nd (epsilon(Nd)(t) = -13.39 to -12.78) and Hf (epsilon(Hf)(t) = -4.8 to -2.0), suggesting that they were derived mainly from garnet-bearing lower continental crust. The geochemical characteristics of the bimodal magmatic associations are comparable to those of associations that form in a continental rift setting. Results indicate that Early Cretaceous magmatism occurred across the whole Tethyan Himalaya, named here as the "Tethyan Himalaya igneous province". Separation of the Tethyan Himalaya from the Indian craton may have occurred during ongoing Early Cretaceous extension related to the Kerguelen mantle plume during the nascent stages of a global plate-reorganization event. If this is the case, our findings provide clues to the nature of the Tethyan Himalaya, challenging traditional view of the India-Asia single-stage collision model. (C) 2018 Elsevier B.V. All rights reserved. |
| WOS ID | WOS:000432499200003 |
| Language | 英语 |
| Indexed By | SCIE |
| Keyword | HF ISOTOPE CONSTRAINTS MANTLE AGE PETROGENESIS EVOLUTION COLLISION VESTIGES BASALTS MODEL TIBET |
| WOS Research Area | Geochemistry & Geophysics |
| WOS Subject | Geochemistry & Geophysics |
| Cooperation Status | 国内 |
| ISSN | 0012-821X |
| Department | 大陆碰撞与高原隆升重点实验室 |
| Publisher | ELSEVIER SCIENCE BV |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.itpcas.ac.cn/handle/131C11/8638 |
| Collection | 图书馆 |
| Affiliation | 1.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100101, Peoples R China; 2.Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China; 3.Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China. |
| Recommended Citation GB/T 7714 | Chen, SS ,Fan, WM ,Shi, RD ,et al. 118-115 Ma magmatism in the Tethyan Himalaya igneous province: Constraints on Early Cretaceous rifting of the northern margin of Greater India[J]. EARTH AND PLANETARY SCIENCE LETTERS,2018,491(0):21-33. |
| APA | Chen, SS ,Fan, WM ,Shi, RD ,Liu, XH ,&Zhou, XJ .(2018).118-115 Ma magmatism in the Tethyan Himalaya igneous province: Constraints on Early Cretaceous rifting of the northern margin of Greater India.EARTH AND PLANETARY SCIENCE LETTERS,491(0),21-33. |
| MLA | Chen, SS ,et al."118-115 Ma magmatism in the Tethyan Himalaya igneous province: Constraints on Early Cretaceous rifting of the northern margin of Greater India".EARTH AND PLANETARY SCIENCE LETTERS 491.0(2018):21-33. |
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| 2018178.pdf（2559KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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