Petrological, geochemical and geochronological constraints on the origin of the Xiadong Ural-Alaskan type complex in NW China and tectonic implication for the evolution of southern Central Asian Orogenic Belt

doi:10.1016/j.lithos.2014.05.005

	Petrological, geochemical and geochronological constraints on the origin of the Xiadong Ural-Alaskan type complex in NW China and tectonic implication for the evolution of southern Central Asian Orogenic Belt
	Su, Ben-Xun 1,2,3; Qin, Ke-Zhang 1; Zhou, Mei-Fu 2; Sakyi, Patrick Asamoah 4; Thakurta, Joyashish 5; Tang, Dong-Mei 1; Liu, Ping-Ping 1,2; Xiao, Qing-Hua 1; Sun, He 1
刊名	LITHOS
	2014-07-01
卷号	200 页码:226-240
关键词	Ural-Alaskan type complex Central Asian Orogenic Belt Mafic-ultramafic complex Arc magmatism
ISSN号	0024-4937
DOI	10.1016/j.lithos.2014.05.005
文献子类	Article
英文摘要	The Xiadong mafic-ultramafic complex is located in the Central Tianshan Terrane, the southern part of the Central Asian Orogenic Belt. It is composed of dunite, hornblende clinopyroxenite, homblendite and hornblende gabbro. Several dykes of hornblendite, hornblende gabbro and gabbroic diorite cut the main body. These rocks are characterized by adcumulate textures. The dunites contain high-Fo (92.3-96.6) olivines with rare orthopyroxene and plagioclase. Hornblende, chromite, and magnetite are common phases in all of the rock types. Geochemically, the rocks of the Xiadong complex display high MgO contents and extremely low trace element abundances. Although the rocks of the main body show higher MgO contents and lower trace element abundance compared to the dykes, both are characterized by flat REE patterns and enrichment of LIE relative to HSFE. These petrological, mineralogical and geochemical features indicate that the Xiadong complex is a typical Ural-Alaskan type complex. The cross-cutting and intrusive relationships of the rock units and their distinct geochemical features suggest that the main body represents a different pulse from the intrusive dyke. The positive whole-rock epsilon(Nd)(t) values, together with variable (Sr-87/Sr-86); ratios, show a depleted mantle source metasomatized by subduction-related material. Zircon U-Pb dating on one hornblende gabbro from the main body of the complex yields a U-Pb Pb-206/U-238 age of 479 Ma, and zircons from three samples of the dykes yield ages of 477, 379 and 313 Ma. All the zircons have positive epsilon(Hf)(t) and slightly higher delta O-18 than normal mantle, and their Hf-O isotopic values are correlated to their ages. The older samples are comparable to those from the Permian mafic-ultramafic complexes in the Beishan Terrane, which were derived from a mantle source metasomatized by subduction of the South Tianshan ocean, while the younger samples are similar to those from the Paleozoic complexes in the Eastern Tianshan, which record the subduction features of the Junggar ocean. These results suggest that the Central Tianshan was a continental arc from at least the Ordovician to the Carboniferous. The lithospheric mantle beneath the Central Tianshan was depleted in Sr-Nd-Hf isotopic compositions and was metasomatized by melts and/or fluids from the subduction of the South Tianshan and Junggar oceans in Paleozoic. The formation of the Xiadong Ural-Alaskan type complex was the product of arc magmatism via high-degree melting of the lithospheric mantle beneath the southern Central Asian Orogenic Belt. (C) 2014 Elsevier B.V. All rights reserved.
WOS关键词	MAFIC-ULTRAMAFIC INTRUSIONS ; ZIRCON U-PB ; FAR-EAST RUSSIA ; CONTINENTAL GROWTH ; BEISHAN AREA ; CRUSTAL CONTAMINATION ; SOUTHEASTERN ALASKA ; ISOTOPE EVIDENCE ; OSMIUM-ISOTOPE ; ALTAY OROGENS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000338810700016
资助机构	National Natural Science Foundation of China(41030424) ; National Natural Science Foundation of China(41030424) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Hong Kong Scholars Program(XJ2012048) ; Hong Kong Scholars Program(XJ2012048) ; National Natural Science Foundation of China(41030424) ; National Natural Science Foundation of China(41030424) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Hong Kong Scholars Program(XJ2012048) ; Hong Kong Scholars Program(XJ2012048) ; National Natural Science Foundation of China(41030424) ; National Natural Science Foundation of China(41030424) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Hong Kong Scholars Program(XJ2012048) ; Hong Kong Scholars Program(XJ2012048) ; National Natural Science Foundation of China(41030424) ; National Natural Science Foundation of China(41030424) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Opening Foundation of State Key Laboratory of Continental Dynamics, Northwest University(10LCD 05) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(20128000101) ; Hong Kong Scholars Program(XJ2012048) ; Hong Kong Scholars Program(XJ2012048)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/84996]
专题	中国科学院地质与地球物理研究所
通讯作者	Su, Ben-Xun
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China 2.Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong, Peoples R China 3.NW Univ Xian, State Key Lab Continental Dynam, Xian 710069, Peoples R China 4.Univ Ghana, Dept Earth Sci, Legon, Accra, Ghana 5.Western Michigan Univ, Dept Geosci, Kalamazoo, MI 49008 USA
推荐引用方式 GB/T 7714	Su, Ben-Xun,Qin, Ke-Zhang,Zhou, Mei-Fu,et al. Petrological, geochemical and geochronological constraints on the origin of the Xiadong Ural-Alaskan type complex in NW China and tectonic implication for the evolution of southern Central Asian Orogenic Belt[J]. LITHOS,2014,200:226-240.
APA	Su, Ben-Xun.,Qin, Ke-Zhang.,Zhou, Mei-Fu.,Sakyi, Patrick Asamoah.,Thakurta, Joyashish.,...&Sun, He.(2014).Petrological, geochemical and geochronological constraints on the origin of the Xiadong Ural-Alaskan type complex in NW China and tectonic implication for the evolution of southern Central Asian Orogenic Belt.LITHOS,200,226-240.
MLA	Su, Ben-Xun,et al."Petrological, geochemical and geochronological constraints on the origin of the Xiadong Ural-Alaskan type complex in NW China and tectonic implication for the evolution of southern Central Asian Orogenic Belt".LITHOS 200(2014):226-240.