The Central Tianshan Block: A microcontinent with a Neoarchean-Paleoproterozoic basement in the southwestern Central Asian Orogenic Belt

doi:10.1016/j.precamres.2017.03.030

CORC > 地质与地球物理研究所 > 中国科学院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

	The Central Tianshan Block: A microcontinent with a Neoarchean-Paleoproterozoic basement in the southwestern Central Asian Orogenic Belt
	Wang, Xin-Shui 1; Gao, Jun 1,2; Klemd, Reiner 3; Jiang, Tuo 4; Li, Ji-Lei 1; Zhang, Xi 5; Xue, Sheng-Chao 6
刊名	PRECAMBRIAN RESEARCH
	2017-07-01
卷号	295 页码:130-150
关键词	Central Tianshan Block Crustal evolution Precambrian basement Tarim Craton Central Asian Orogenic Belt
ISSN号	0301-9268
DOI	10.1016/j.precamres.2017.03.030
文献子类	Article
英文摘要	The Central Tianshan Block (CTB) is one of the major continental constituents of the western Central Asian Orogenic Belt (CAOB). Its nature and origin is essential for understanding the accretionary processes and the reconstruction of the architectural framework of the CAOB. The Wuwamen Metamorphic Complex (WMC), which is believed to represent the basement of the CTB, was incorporated into the Wuwamen ophiolitic melange during the Paleozoic evolution of the South Tianshan Ocean. The WMC is mainly composed of amphibolite-facies volcano-sedimentary rocks, including migmatites, orthogneisses, amphibolites, schists and locally marbles. Zircon U-Pb geochronology suggests that the protoliths of the interlayered biotite-two feldspar and biotite-plagioclase-hornblende gneisses in the Yangjuan area were formed between 2529 and 2513 Ma and overprinted by amphibolite-facies metamorphism between 1815 and 1809 Ma. Subsequently, the gneisses were intruded by-4724 Ma meta-mafic dykes and similar to 787 Ma leucogranite dykes/veins. Geochemical data reveal that the biotitetwo feldspar gneisses have high-silica adakite affinities with high SiO2 and Na2O contents as well as high Sr/Y ratios (61-117) and slightly evolved zircon Hf isotopic compositions. Consequently, they are interpreted to be the products of partial melting of relatively old subducted oceanic crust. In contrast, the interlayered biotite-plagioclase-hornblende gneisses have high MgO, Cr, Co and Ni contents and prominent negative Nb-Ta-Ti anomalies, indicating derivation from partial melting of an ancient subcontinental lithospheric mantle in a continental arc setting. The similar to 1.72 Ga meta-mafic dykes have geochemical similarities of typical Fe-Ti basalts and are characterized by incompatible element enrichments and primitive Sr-Nd-Hf isotopic signatures ((Sr-87/Sr-86); = 0.703446- 0.703535); epsilon(Nd)(t) = +6.49 to +6.90; zircon epsilon(Hf)(t) = +0.57 to +10.6), which is consistent with partial melting of a relatively fertile, isotopically depleted asthenospheric mantle in a post-collisional extensional setting. In addition, the-787 Ma leucogranites are trondhjemitic in composition and display extremely low total REE contents and highly evolved Nd-Hf isotopic signatures (epsilon(Nd)(t) =-4.71 to-4.53; zircon epsilon(Hf)(t) =-19.4 to-13.0). They are thought to have no petrogenetic relationship with the host orthogneisses and to be products of a foreign melt injection. Our new data provide robust evidence for a Neoarchean-Paleoproterozoic basement of the CTB. Comparison of the tectono-thermal-magmatic events reveals that the CTB and the Tarim Craton have a partly overlapping Precambrian crustal evolution, and thus the CTB could have originated from the Tarim Craton. However, a major difference between both is the presence of juvenile Mesoproterozoic magmatism in the CTB and its absence in the Tarim Craton and, therefore, further geological and geochronological research is required to determine the precise origin of the CTB and its tectonic affinity with adjacent terranes in the western CAOB. (C) 2017 Elsevier B.V. All rights reserved.
WOS关键词	ZIRCON U-PB ; PALEOZOIC TECTONIC EVOLUTION ; NEOPROTEROZOIC GRANITIC GNEISSES ; NORTHERN TARIM CRATON ; PRECAMBRIAN CRUSTAL EVOLUTION ; CHINESE SOUTH TIANSHAN ; KYRGYZ TIEN-SHAN ; NW-CHINA ; GEOCHRONOLOGICAL EVIDENCE ; YILI BLOCK
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000402947200009
资助机构	National Natural Science Foundation of China(41390445 ; China Postdoctoral Science Foundation(2016M600127) ; Short-Term Grants of the German Academic Exchange Service (DAAD) ; 41025008) ; National Natural Science Foundation of China(41390445 ; China Postdoctoral Science Foundation(2016M600127) ; Short-Term Grants of the German Academic Exchange Service (DAAD) ; 41025008) ; National Natural Science Foundation of China(41390445 ; China Postdoctoral Science Foundation(2016M600127) ; Short-Term Grants of the German Academic Exchange Service (DAAD) ; 41025008) ; National Natural Science Foundation of China(41390445 ; China Postdoctoral Science Foundation(2016M600127) ; Short-Term Grants of the German Academic Exchange Service (DAAD) ; 41025008)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/52874]
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	Gao, Jun
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, POB 9825, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth Sci, Beijing 100049, Peoples R China 3.Univ Erlangen Nurnberg, GeoZentrum Nordbayern, Schlossgarten 5a, D-91054 Erlangen, Germany 4.Wuhan Ctr China Geol Survey, Lab Isotope Geochem, Wuhan 430205, Peoples R China 5.China Minmet Corp, Beijing 100010, Peoples R China 6.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing 100083, Peoples R China
推荐引用方式 GB/T 7714	Wang, Xin-Shui,Gao, Jun,Klemd, Reiner,et al. The Central Tianshan Block: A microcontinent with a Neoarchean-Paleoproterozoic basement in the southwestern Central Asian Orogenic Belt[J]. PRECAMBRIAN RESEARCH,2017,295:130-150.
APA	Wang, Xin-Shui.,Gao, Jun.,Klemd, Reiner.,Jiang, Tuo.,Li, Ji-Lei.,...&Xue, Sheng-Chao.(2017).The Central Tianshan Block: A microcontinent with a Neoarchean-Paleoproterozoic basement in the southwestern Central Asian Orogenic Belt.PRECAMBRIAN RESEARCH,295,130-150.
MLA	Wang, Xin-Shui,et al."The Central Tianshan Block: A microcontinent with a Neoarchean-Paleoproterozoic basement in the southwestern Central Asian Orogenic Belt".PRECAMBRIAN RESEARCH 295(2017):130-150.