Underplating of basaltic magmas and crustal growth in a continental arc: Evidence from Late Mesozoic intermediate-felsic intrusive rocks in southern Qiangtang, central Tibet
文献类型：期刊论文
| 作者 | Hao, Lu-Lu1,2; Wang, Qiang1,3; Wyman, Derek A.4; Ou, Quan1,2; Dan, Wei1; Jiang, Zi-Qi1,5; Wu, Fu-Yuan6; Yang, Jin-Hui6; Long, Xiao-Ping1; Li, Jie1 |
| 刊名 | LITHOS
 |
| 出版日期 | 2016-02-15 |
| 卷号 | 245页码:223-242 |
| 关键词 | Crustal Growth Underplating Adakites Late Mesozoic Qiangtang Tibet |
| DOI | 10.1016/j.lithos.2015.09.015 |
| 文献子类 | Article |
| 英文摘要 | Phanerozoic growth of continental crust has widely been considered as an important geological phenomenon and mainly occurs in an arc setting. However, the crustal growth models (mantle-derived basalt underplating or accretion of island or intra-oceanic arc complexes or oceanic plateau) have been disputed. Here we present new zircon LA-ICPMS U-Pb age, whole-rock major and trace element, Sr-Nd and zircon Hf isotopic data for Late Mesozoic intermediate-felsic intrusive rocks in the Rena Co area in southern Qiangtang, central Tibet. LA-ICP-MS zircon U-Pb dating for two granodiorite and three diorite samples and one granodiorite porphyry sample gives ages of ca 150 Ma, ca. 112 Ma, respectively, indicating they were generated in the Late Jurassic-Early Cretaceous. All rocks are sub-alkaline in composition and belong to the high-K cal-alkaline series. The similar to 150 Ma diorites (SiO2 = 57.9-612 wt.%) exhibit relatively high MgO (3.13-3.88 wt.%) and Cr (52.4-282 ppm) contents and Mg-# (47-51) values, similar to magnesian diorites. They are geochemically characterized by uniformly low epsilon(Nd)(t) (-5.5 to -5.2), high (Sr-87/Sr-86)(i) (0.7071 to 0.7078) and Th/La (0.22-0.32), and variable zircon epsilon(Hf)(t) (-8.7 to + 4.8) values. They were probably generated by melting of oceanic sediment diapirs, followed by interaction with the surrounding mantle during the northward subduction of Bangong-Nujiang Oceanic lithosphere. The similar to 150 Ma granodiorites and similar to 112 Ma granodiorite porphyries are characterized by low MgO (<3 wt.%) contents and Mg-# (<45) values, high Al2O3 (>15% wt.%) and Sr (>400 ppm) and low Y (<18 ppm) and Yb (<1.9 ppm) contents, and high Sr/Y and La/Yb ratios, which are similar to those of typical adakites. The granodiorites have low epsilon(Nd)(t) (-7.6 to -3.7) and zircon epsilon(Hf)(t) (-9.8 to +0.2) and high (Sr-87/Sr-86)(i) (0.7069 to 0.7086) values, and were likely produced by partial melting of a thickened and heterogeneous ancient lower continental crust. The relatively depleted isotope compositions [((87S)r/8(6)Sr); = 0.7054-0.7065; epsilon(Nd)(t) = 0.61 to + 0.25; zircon epsilon(Hf)(t) = +4.7 to +9.7] of the granodiorite porphyries indicate that they were most probably generated by partial melting of newly underplated and thickened basaltic lower crust. Taking into account ophiolites in the Bangong-Nujiang Suture and Late Mesozoic magmatic rocks in the southern Qiangtang sub-block, we suggest that this area was located in a continental arc setting. Moreover, from the Late Jurassic to Early Cretaceous, the ancient lower crust in the southern Qiangtang sub-block was gradually replaced by mantle-derived juvenile materials. The crustal evolution indicates that, in a continental arc, basaltic magma underplating plays a key role in vertical crustal growth. (C) 2015 Elsevier B.V. All rights reserved. |
| WOS关键词 | U-PB GEOCHRONOLOGY ; HF ISOTOPIC COMPOSITIONS ; INDO-ASIAN COLLISION ; SLAB-DERIVED MELTS ; HIGH-MG ANDESITES ; VOLCANIC-ROCKS ; TECTONIC IMPLICATIONS ; LU-HF ; SUBDUCTED LITHOSPHERE ; MANTLE CONTRIBUTIONS |
| WOS研究方向 | Geochemistry & Geophysics ; Mineralogy |
| 语种 | 英语 |
| WOS记录号 | WOS:000371945200017 |
| 资助机构 | Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS 135 project)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS 135 project)(Y234021001) ; 41202040 ; 41202040 ; 41421062) ; 41421062) ; Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS 135 project)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS 135 project)(Y234021001) ; 41202040 ; 41202040 ; 41421062) ; 41421062) |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/62031]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China 2.Univ Chinese Acad Sci, Beijing 10069, Peoples R China 3.CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing, Peoples R China 4.Univ Sydney, Sch Geosci, Sydney, NSW 2006, Australia 5.Guilin Univ Technol, Sch Earth Sci, Guilin 541004, Peoples R China 6.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Hao, Lu-Lu,Wang, Qiang,Wyman, Derek A.,et al. Underplating of basaltic magmas and crustal growth in a continental arc: Evidence from Late Mesozoic intermediate-felsic intrusive rocks in southern Qiangtang, central Tibet[J]. LITHOS,2016,245:223-242. |
| APA | Hao, Lu-Lu.,Wang, Qiang.,Wyman, Derek A..,Ou, Quan.,Dan, Wei.,...&Li, Jie.(2016).Underplating of basaltic magmas and crustal growth in a continental arc: Evidence from Late Mesozoic intermediate-felsic intrusive rocks in southern Qiangtang, central Tibet.LITHOS,245,223-242. |
| MLA | Hao, Lu-Lu,et al."Underplating of basaltic magmas and crustal growth in a continental arc: Evidence from Late Mesozoic intermediate-felsic intrusive rocks in southern Qiangtang, central Tibet".LITHOS 245(2016):223-242. |
入库方式： OAI收割
来源：地质与地球物理研究所
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