Two contrasting late Paleozoic magmatic episodes in the northwestern Chinese Tianshan Belt, NW China: Implication for tectonic transition from plate convergence to intra-plate adjustment during accretionary orogenesis

doi:10.1016/j.jseaes.2017.03.013

	Two contrasting late Paleozoic magmatic episodes in the northwestern Chinese Tianshan Belt, NW China: Implication for tectonic transition from plate convergence to intra-plate adjustment during accretionary orogenesis
	Wang, Xiangsong 1,2,3; Cai, Keda 1,2; Sun, Min 4; Xiao, Wenjiao 1,2; Xia, Xiaoping 3,6; Wan, Bo 3,5; Bao, Zihe 1,2,3; Wang, Yannan 1,2,3
刊名	JOURNAL OF ASIAN EARTH SCIENCES
	2018-03-01
卷号	153 页码:118-138
关键词	Tianshan Central Asian Orogenic Belt Terrane assembly Slab break-off Accretionary orogenesis
ISSN号	1367-9120
DOI	10.1016/j.jseaes.2017.03.013
文献子类	Article
英文摘要	Late Carboniferous to Early Permian is a critical period for the final amalgamation of the Central Asian Orogenic Belt (CAOB). However, as most of the accreted terranes of the CAOB are unclear in tectonic nature and origin, the timing and processes of their mutual amalgamation have been poorly constrained. To understand assembly of the West Junggar Terrane with the Yili Block, a suite of the late Paleozoic magmatic rocks, including ignimbrite, rhyolite and granite, in northwestern Chinese Tianshan Belt were studied for their petrogenesis and tectonic implications. Our new results of secondary ion mass spectrometry (SIMS) zircon U-Pb dating reveal two separate magmatic episodes, ca. 300 Ma volcanism (ignimbrite and rhyolite) and ca. 288 Ma plutonsim (biotite granite). Geochemically, for the ca. 300 Ma volcanism, the ignimbrites have low SiO2 (65.8-71.5 wt.%) and Mg-# (6-13) values, and exhibit arc affinity with significantly enriched in large ion lithophile elements (LILE) and depleted in high field strength elements (HFSE) such as Nb, Ta and Ti. The whole-rock epsilon(Nd)(t) and zircon epsilon(Nf)(t) values range from +6.9 to +7.0 and +9.9 to +14.1 respectively, indicating a juvenile basaltic lower crustal origin. Rhyolites have slightly high SiO2 (72.7-74.0 wt.%) and K2O (3.86-4.53 wt.%) contents, high zircon 6180 (11.67-13.2 parts per thousand) values, and low whole-rock epsilon(Nd)(t) (+2.9 to +3.8) and zircon epsilon(Nf)(t) (+2.8 to +10.0) values, which may suggest sediment involvements during magma generation. In contrast, for the ca. 288 Ma plutonism, the biotite granites have obviously higher SiO2 (74.7-75.5 wt.%) contents and whole-rock epsilon(Nd)(t) (+7.7 to +8.8), zircon ENO) (+9.8 to +12.7), and lower zircon delta O-18 (5.99-6.84%,,) values, than those of the ca. 300 Ma volcanic rocks, which are consistent with signatures of juvenile magma source. According to our estimates of zircon saturation temperatures, together with their contrasting genesis, we attribute the formation of ca. 300 Ma high temperature (815-938 degrees C) volcanism to oceanic slab break-off during assembly of the West Junggar Terrane with the Yili Block, and relate the generation of ca. 288 Ma low temperature (723-735 degrees C) plutonism to subsequent strike-slipping of North Tianshan Fault that facilitated introduction of water-fluxes triggering hydrous partial melting of juvenile lower crust. The sequential magmatic episodes in the northwestern Chinese Tianshan Belt may provide a crucial clue to a tectonic transition from plate convergence to intra-plate adjustment during the formation of the Kazakhstan Orocline in the late Paleozoic. (C) 2017 Elsevier Ltd. All rights reserved.
WOS关键词	PHANEROZOIC CRUSTAL GROWTH ; ARC-CONTINENT COLLISION ; U-PB GEOCHRONOLOGY ; CARBONIFEROUS VOLCANIC-ROCKS ; A-TYPE GRANITES ; EASTERN ALATAW MOUNTAINS ; HF ISOTOPIC COMPOSITIONS ; NORTH TIEN-SHAN ; CENTRAL-ASIA ; WESTERN TIANSHAN
WOS研究方向	Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000424181200007
资助机构	Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Hong Kong Research Grant Council(704313P) ; Hong Kong Research Grant Council(704313P) ; National Science Foundation of China(41622205) ; National Science Foundation of China(41622205) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Hong Kong Research Grant Council(704313P) ; Hong Kong Research Grant Council(704313P) ; National Science Foundation of China(41622205) ; National Science Foundation of China(41622205) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Hong Kong Research Grant Council(704313P) ; Hong Kong Research Grant Council(704313P) ; National Science Foundation of China(41622205) ; National Science Foundation of China(41622205) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Major Basic Research Project of the Ministry of Science and Technology of China(2014CB448000) ; Hong Kong Research Grant Council(704313P) ; Hong Kong Research Grant Council(704313P) ; National Science Foundation of China(41622205) ; National Science Foundation of China(41622205)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/82892]
专题	中国科学院地质与地球物理研究所
通讯作者	Cai, Keda
作者单位	1.Chinese Acad Sci, Xinjiang Inst Ecol & Geog, 818 South Beijing Rd, Urumqi 830011, Xinjiang, Peoples R China 2.Xinjiang Key Lab Mineral Resources & Digital Geol, Urumqi 830011, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100029, Peoples R China 4.Univ Hong Kong, Dept Earth Sci, Pokflam Rd, Hong Kong, Hong Kong, Peoples R China 5.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 6.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510460, Guangdong, Peoples R China
推荐引用方式 GB/T 7714	Wang, Xiangsong,Cai, Keda,Sun, Min,et al. Two contrasting late Paleozoic magmatic episodes in the northwestern Chinese Tianshan Belt, NW China: Implication for tectonic transition from plate convergence to intra-plate adjustment during accretionary orogenesis[J]. JOURNAL OF ASIAN EARTH SCIENCES,2018,153:118-138.
APA	Wang, Xiangsong.,Cai, Keda.,Sun, Min.,Xiao, Wenjiao.,Xia, Xiaoping.,...&Wang, Yannan.(2018).Two contrasting late Paleozoic magmatic episodes in the northwestern Chinese Tianshan Belt, NW China: Implication for tectonic transition from plate convergence to intra-plate adjustment during accretionary orogenesis.JOURNAL OF ASIAN EARTH SCIENCES,153,118-138.
MLA	Wang, Xiangsong,et al."Two contrasting late Paleozoic magmatic episodes in the northwestern Chinese Tianshan Belt, NW China: Implication for tectonic transition from plate convergence to intra-plate adjustment during accretionary orogenesis".JOURNAL OF ASIAN EARTH SCIENCES 153(2018):118-138.