PERMIAN GRANITOIDS IN THE CHINESE ALTAI OROGEN: GEOCHRONOLOGY, PETROGENESIS AND TECTONIC IMPLICATIONS

doi:10.2475/01.2014.03

	PERMIAN GRANITOIDS IN THE CHINESE ALTAI OROGEN: GEOCHRONOLOGY, PETROGENESIS AND TECTONIC IMPLICATIONS
	Tong, Ying 7; Wang, Tao ; Jahn, Bor-ming ; Sun, Min ; Hong, Da-wei ; Gao, Jian-feng
刊名	AMERICAN JOURNAL OF SCIENCE
	2014
卷号	314 期号:1 页码:80-109
关键词	Altai zircon U-Pb age granitoids Permian post-collisional CAOB (Central Asian Orogenic Belt)
ISSN号	0002-9599
DOI	10.2475/01.2014.03
英文摘要	The Altai orogen is an important constituent of the Central Asian Orogenic Belt (CAOB). The main orogenic processes occurred mainly in the early to middle Paleozoic and involved a series of northward subduction and terrane accretion. However, termination of the accretionary and post-accretionary processes remains poorly defined. The Chinese Altai is located in the southern part of this orogeny, which is widely intruded by Permian granitic plutons. These plutons are approximately circular in shape, free of deformation and generally cutting pre-Permian structures, suggesting a post-tectonic formation. We report the results of geochronological and geochemical data from five specific granitic plutons (Buerjin, Xibodu, Daqiaonan, Aweitan, and Adenbluk), which all yielded magmatic zircon U-Pb ages of about 270 Ma. These plutons are composed of high-K calc-alkaline rocks, including K-feldspar megaphyric granite, biotite granite and monzogranite that have metaluminous to weakly LREE-enriched, coupled with negative Eu anomalies. Significant negative anomalies of Ba, Sr, P, and Ti are also observed in the primitive-mantle normalized diagram. They have positive whole-rock epsilon(Nd)(t) (+1.3 to +7.2) and zircon epsilon(Hf)(t) values (+5.6 to +12.9), yielding Sm-Nd model ages of <=.0.9 Ga. Therefore, these granitoids are proposed to have been generated by differentiation of mantle-derived magmas with variable crustal contamination. In view of the field occurrence, structural analysis, regional tectonics and geochemical characteristics, these Permian plutons are concluded to be post-accretionary or post-collisional. Asthenospheric upwelling after the collision and amalgamation of the Altai and Junggar blocks could have caused the mantle-derived magmas that evolved to form the granitoids. We note that Permian intrusions are not only widespread but also voluminous in the CAOB. They mostly are post-collisional products, and some of them might have been related to the large igneous province activity in the Tarim Block.
学科主题	火成岩岩石学
WOS关键词	ZIRCON U-PB ; HF ISOTOPIC COMPOSITIONS ; A-TYPE GRANITES ; NW CHINA ; CENTRAL-ASIA ; CONTINENTAL GROWTH ; NORTH XINJIANG ; GEOLOGICAL IMPLICATIONS ; RIDGE-SUBDUCTION ; MANTLE PLUME
WOS研究方向	Geology
语种	英语
出版者	AMER JOURNAL SCIENCE
WOS记录号	WOS:000333945400005
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40562]
专题	中国地质科学院地质研究所
作者单位	1.[Tong, Ying 2.Wang, Tao 3.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China 4.Natl Taiwan Univ, Dept Geosci, Taipei 106, Taiwan 5.[Sun, Min 6.Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong, Peoples R China 7.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Tong, Ying,Wang, Tao,Jahn, Bor-ming,et al. PERMIAN GRANITOIDS IN THE CHINESE ALTAI OROGEN: GEOCHRONOLOGY, PETROGENESIS AND TECTONIC IMPLICATIONS[J]. AMERICAN JOURNAL OF SCIENCE,2014,314(1):80-109.
APA	Tong, Ying,Wang, Tao,Jahn, Bor-ming,Sun, Min,Hong, Da-wei,&Gao, Jian-feng.(2014).PERMIAN GRANITOIDS IN THE CHINESE ALTAI OROGEN: GEOCHRONOLOGY, PETROGENESIS AND TECTONIC IMPLICATIONS.AMERICAN JOURNAL OF SCIENCE,314(1),80-109.
MLA	Tong, Ying,et al."PERMIAN GRANITOIDS IN THE CHINESE ALTAI OROGEN: GEOCHRONOLOGY, PETROGENESIS AND TECTONIC IMPLICATIONS".AMERICAN JOURNAL OF SCIENCE 314.1(2014):80-109.