| Middle Triassic ultrapotassic rhyolites from the Tanggula Pass, southern Qiangtang, China: A previously unrecognized stage of silicic magmatism | |
| Chen, SS (Chen, Sheng-Sheng)1,2,3; Shi, RD (Shi, Ren-Deng)1,2; Fan, WM (Fan, Wei-Ming)1,2; Zou, HB (Zou, Hai-Bo)4; Liu, DL (Liu, De-Liang)1; Huang, QS (Huang, Qi-Shuai)1; Gong, XH (Gong, Xiao-Han)1,3; Yi, GD (Yi, Guo-Ding)1,3; Wu, K (Wu, Kang)1,3; Chen, SS | |
| Source Publication | LITHOS
 |
| 2016 | |
| Volume | 264Issue:0Pages:258-276 |
| DOI | 10.1016/j.lithos.2016.08.040 |
| Abstract | There is a Mid-Late Mesozoic (Jurassic-Cretaceous) arc magmatic belt in southern Qiangtang subterrane associated with the north-dipping subduction of the Bangong-Nujiang Tethyan Ocean. Early Mesozoic (Triassic) magmatism, tectonic evolution of the southern Qjangtang subterrane, and the mechanism of its crustal growth, however, remain unclear. This paper reports zircon U-Pb age, whole-rock major, trace elemental, and Sr-Nd-Hf isotopic components for the Mesozoic Tanggula Pass rhyolites in southern Qiangtang subterrane. Our new data reveal a significant, previously unrecognized stage of magmatism in southern Qiangtang subterrane. The Tanggula Pass rhyolites are moderately-strongly peraluminous (A/CNK = 1.09-1.54), highly fractionated (SiO2 > 73%) and ultrapotassic (K2O/Na2O > 44%). Zircon U-Pb dating by LA-ICP-MS yields a concordant age with a weighted mean Pb-206/U-238 age of 235.9 +/- 0.86 Ma (n = 18, MSWD = 0.25). The large variations of major and trace element concentrations are mainly attributed to fractional crystallization of plagioclase, hornblende, Fe-Ti oxides, and accessory minerals such as apatite, allanite, monazite, and zircon in the shallow level. K-feldspar mainly occurs as cumulated mineral, resulting in high K2O contents and K2O/Na2O ratios. The rhyolites were derived by partial melting of mixed source rocks including older sedimentary rocks in the upper crust and juvenile materials, triggered by north-dipping subduction of the Bangong-Nujiang Tethyan oceanic lithosphere. The eruption age of Middle Triassic suggests that the initiation of northward subduction of the Bangong-Nujiang Tethyan ocean took place earlier than is currently assumed. Whole-rock Nd (ca. 155 to 234 Ga) and zircon Hf (ca. 1.77 to 2.33 Ga) data reflect the presence of the Proterozoic basement in the southern Qiangtang subterrane. Basaltic magma underplating and accretion of intra-oceanic arc complexes and oceanic plateau contributed to vertical crustal growth and lateral crustal growth, respectively. (C) 2016 Elsevier B.V. All rights reserved. |
| Subject Area | 地质学 |
| WOS ID | WOS:000387191600019 |
| Language | 英语 |
| Indexed By | SCI |
| Keyword | U-pb Geochronology I-type Granites Ionization Mass-spectrometry Trace-element Composition Hf Isotopic Compositions Nujiang Suture Zone Volcanic-rocks Central Tibet Calc-alkaline Lower Crust |
| Cooperation Status | 国际 |
| Department | 碰撞与隆升 |
| Subtype | Article |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.itpcas.ac.cn/handle/131C11/7511 |
| Collection | 图书馆 |
| Corresponding Author | Chen, SS |
| 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 4.Auburn Univ, Dept Geosci, Auburn, AL 36849 USA |
| Recommended Citation GB/T 7714 | Chen, SS ,Shi, RD ,Fan, WM ,et al. Middle Triassic ultrapotassic rhyolites from the Tanggula Pass, southern Qiangtang, China: A previously unrecognized stage of silicic magmatism[J]. LITHOS,2016,264(0):258-276. |
| APA | Chen, SS .,Shi, RD .,Fan, WM .,Zou, HB .,Liu, DL .,...&Chen, SS.(2016).Middle Triassic ultrapotassic rhyolites from the Tanggula Pass, southern Qiangtang, China: A previously unrecognized stage of silicic magmatism.LITHOS,264(0),258-276. |
| MLA | Chen, SS ,et al."Middle Triassic ultrapotassic rhyolites from the Tanggula Pass, southern Qiangtang, China: A previously unrecognized stage of silicic magmatism".LITHOS 264.0(2016):258-276. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| V.264 258-276 2016.p（1916KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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