Age, origin, and tectonic implications of Palaeozoic rapakivi granites;in the North Qaidam orogen, Northwest China

doi:10.1080/00206814.2013.767434

	Age, origin, and tectonic implications of Palaeozoic rapakivi granites;in the North Qaidam orogen, Northwest China
	Wang, Xiaoxia 6; Hu, Nenggao 1; Castro, Antonio 2; Wang, Tao 3; Lu, Xingxiang 4
刊名	INTERNATIONAL GEOLOGY REVIEW
	2013
卷号	55 期号:9 页码:1087-1108
关键词	rapakivi granite geochemistry origin Paleozoic magmatism North Qaidam
ISSN号	0020-6814
DOI	10.1080/00206814.2013.767434
英文摘要	Palaeozoic rapakivi granites occur in the western segment of the China Central Orogenic System. Exhibiting typical rapakivi texture, these granites contain magmatic microgranular enclaves of intermediate compositions. SHRIMP zircon U-Pb ages for the granites and enclaves are 433 +/- 5 Ma and 433 +/- 3 Ma, respectively. The rapakivi granites are magnesian to ferroan, calc-alkalic to alkalic, and are characterized by high FeOt/(FeOt+MgO) (0.74-0.91) and Ga/Al ratios, and SiO2, Na2O+K2O and rare earth element (apart from Eu) contents, but low CaO, Ba, and Sr contents. These are typical A-type granite geochemical features. The granites and enclaves exhibit a uniform decrease in TiO2, CaO, Na2O, K2O, FeO, and MgO with increasing SiO2, and both lithologies have similar trace element patterns. Whole-rock E-Nd(t) values vary from-9.2 to-8.7 for the granites and from-9.0 to-8.4 for the enclaves, but zircon E-Hf(t) values vary more widely from-5.8 to-0.2 and-4.6 to +5.1, respectively. Our data suggest that the granites and enclaves have crystallized from different magmas. The granites appear to have been derived from old continental crust, whereas the enclaves required a source having a juvenile component. The spherical shape and undeformed nature of the granites and their geochemical characteristics, coupled with the (ultra)-high pressure metamorphism and evolution of Palaeozoic granitoid magmatism in the North Qaidam orogen, indicate that the rapakivi granites were generated in a post-collisional setting. These rocks are therefore an example of Palaeozoic rapakivi granites emplaced in a post-collisional, extensional orogenic setting.
学科主题	火成岩岩石学
WOS关键词	A-TYPE GRANITES ; ZIRCON U-PB ; ND ISOTOPIC COMPOSITIONS ; UHP METAMORPHIC ; BELT ; WESTERN CHINA ; NW CHINA ; LU-HF ; GEOLOGICAL SIGNIFICANCE ; SOUTHEASTERN AUSTRALIA ; CRUSTAL EVOLUTION
WOS研究方向	Geology
语种	英语
出版者	TAYLOR & FRANCIS INC
WOS记录号	WOS:000320574700003
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40024]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Resources, MLR Key Lab Metallogeny & Mineral Assessment, Beijing 100037, Peoples R China. 2.Changan Univ, Xian 710054, Peoples R China. 3.Univ Huelva, Dept Geol, Huelva 21071, Spain. 4.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 5.Henan Acad Geol Sci, Inst Geol, Zhengzhou 450054, Peoples R China. 6.中国地质科学院矿产资源研究所
推荐引用方式 GB/T 7714	Wang, Xiaoxia,Hu, Nenggao,Castro, Antonio,et al. Age, origin, and tectonic implications of Palaeozoic rapakivi granites;in the North Qaidam orogen, Northwest China[J]. INTERNATIONAL GEOLOGY REVIEW,2013,55(9):1087-1108.
APA	Wang, Xiaoxia,Hu, Nenggao,Castro, Antonio,Wang, Tao,&Lu, Xingxiang.(2013).Age, origin, and tectonic implications of Palaeozoic rapakivi granites;in the North Qaidam orogen, Northwest China.INTERNATIONAL GEOLOGY REVIEW,55(9),1087-1108.
MLA	Wang, Xiaoxia,et al."Age, origin, and tectonic implications of Palaeozoic rapakivi granites;in the North Qaidam orogen, Northwest China".INTERNATIONAL GEOLOGY REVIEW 55.9(2013):1087-1108.