Latest Paleoproterozoic (ca. 1.8-1.6 Ga) extensional tectonic setting in the Dunhuang terrane, NW China: Evidence from geochronological and geochemical investigations on A-type granite and metamafic rock
文献类型：期刊论文
| 作者 | Zhao, Yan1; Ao, Wenhao1; Zhang, Hong1; Wang, Qian1; Zhai, Mingguo1,2,3; Sun, Yong1 |
| 刊名 | LITHOSPHERE
 |
| 出版日期 | 2019-12-01 |
| 卷号 | 11期号:6页码:834-854 |
| ISSN号 | 1941-8264 |
| DOI | 10.1130/L1114.1 |
| 英文摘要 | Latest Paleoproterozoic (ca. 1.8-1.6 Ga) magmatic rocks outcrop in the Dunhuang terrane, represented by A-type granites and mafic (basaltic) rocks that have metamorphosed into amphibolites. The A-type granites, emplaced at ca. 1.79-1.77 Ga, are geochemically characterized by high Na2O + K2O, Fe2O3 T, Zr, Nb, and Ce contents, as well as high Fe2O3T/(Fe2O3T + MgO) and Ga/Al ratios. Furthermore, they have Nb/Ta, Y/Nb, Rb/Nb, and Sc/Nb ratios of 12.10-15.56, 1.45-1.79, 3.52-6.51, and 0.11-0.19, respectively, showing affinity to A(2)-type granite. The A-type granites have negative epsilon(Nd)(t) values (-5.4 to -4.8) with Neoarchean depleted mantle (T-DM2) ages (2591-2494 Ma), corresponding to coupling between E, f (t) values (-4.85 to -0.92) and T-DM2 ages (2817-2556 Ma) of zircons. Therefore, the A-type granite pluton was mostly generated by partial melting of Neoarchean tonalitic to granodioritic basement rocks of the Dunhuang Complex in a postcollisional tectonic setting following a late Paleoproterozoic continent-continent collisional event. The metamafic rocks have a protolith age of 1605 +/- 45 Ma and metamorphic age of 317 +/- 20 Ma, indicating a Paleozoic tectonic event. The metamafic rock samples are geochemically characterized by relatively high alkali (Na2O + K2O = 4.39-4.81 wt%) contents and low Nb/Y (0.63-0.66) ratios, and they show steep rare earth element (REE) patterns with light REE enrichment and insignificant Eu anomalies and Nb-Ta, Zr-Hf, and Ti anomalies, resembling subalkaline oceanicisland basalt affinity. They have positive epsilon(Nd)(t) values (+0.8 to +1.8) close to the chondrite evolutionary line and variable epsilon(Nf)(t) values (-1.09 to +9.06) of zircons. Hence, the protolith of the metamafic rocks may have been produced by magma mixing processes between a depleted mantle source and a metasomatized lithospheric mantle source during the initial rifting stage in an extensional setting, completing the formation of the Precambrian Dunhuang Complex. Considering the ca. 1.85-1.80 Ga regional metamorphism in the Dunhuang terrane, the latest Paleoproterozoic (ca. 1.8-1.6 Ga) A(2)-type granitic magmatism and mafic magmatism documented the postorogenic to initial rifting processes following the global-scale late Paleoproterozoic collisional event, which is comparable with ca. 1.80-1.67 Ga postcollisional and ca. 1.60-1.53 Ga anorogenic magmatism in the North China craton, but different from that of the Tarim craton. |
| WOS关键词 | ZIRCON U-PB ; NORTHEASTERN TARIM CRATON ; HIGH-PRESSURE GRANULITES ; HF ISOTOPE COMPOSITIONS ; SOUTHERN MARGIN ; OROGENIC BELT ; LU-HF ; CRUSTAL EVOLUTION ; PRECAMBRIAN EVOLUTION ; METAMORPHIC EVOLUTION |
| 资助项目 | National Natural Science Foundation of China[41802199] ; National Natural Science Foundation of China[41421002] ; China Postdoctoral Science Foundation[2017M623222] ; Shaanxi Postdoctoral Science Foundation |
| WOS研究方向 | Geochemistry & Geophysics ; Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000498024400005 |
| 出版者 | GEOLOGICAL SOC AMER, INC |
| 资助机构 | National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation ; Shaanxi Postdoctoral Science Foundation |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/95777]  |
| 专题 | 地质与地球物理研究所_中国科学院矿产资源研究重点实验室 |
| 通讯作者 | Zhao, Yan |
| 作者单位 | 1.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Shaanxi, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China 3.Univ Chinese Acad Sci, Key Lab Computat Geodynam, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhao, Yan,Ao, Wenhao,Zhang, Hong,et al. Latest Paleoproterozoic (ca. 1.8-1.6 Ga) extensional tectonic setting in the Dunhuang terrane, NW China: Evidence from geochronological and geochemical investigations on A-type granite and metamafic rock[J]. LITHOSPHERE,2019,11(6):834-854. |
| APA | Zhao, Yan,Ao, Wenhao,Zhang, Hong,Wang, Qian,Zhai, Mingguo,&Sun, Yong.(2019).Latest Paleoproterozoic (ca. 1.8-1.6 Ga) extensional tectonic setting in the Dunhuang terrane, NW China: Evidence from geochronological and geochemical investigations on A-type granite and metamafic rock.LITHOSPHERE,11(6),834-854. |
| MLA | Zhao, Yan,et al."Latest Paleoproterozoic (ca. 1.8-1.6 Ga) extensional tectonic setting in the Dunhuang terrane, NW China: Evidence from geochronological and geochemical investigations on A-type granite and metamafic rock".LITHOSPHERE 11.6(2019):834-854. |
入库方式： OAI收割
来源：地质与地球物理研究所
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