Petrogenesis and geodynamic implications of the Gejiu igneous complex in;the western Cathaysia block, South China

doi:10.1016/j.lithos.2013.04.002

CORC > 中国地质调查局 > 中国地质调查局 > 中国地质科学院矿产资源研究所

	Petrogenesis and geodynamic implications of the Gejiu igneous complex in;the western Cathaysia block, South China
	Cheng, Yanbo 1,2; Mao, Jingwen 1; Spandler, Carl 2
刊名	LITHOS
	2013
卷号	175 页码:213-229
关键词	Igneous complex Zircon U-Pb dating Petrogenesis Lithospheric extension Gejiu district Western Cathaysia block
ISSN号	0024-4937
DOI	10.1016/j.lithos.2013.04.002
英文摘要	The Gejiu tin district in western Cathaysia block comprises a series of igneous rocks including equigranular and porphyritic granites, gabbro and nepheline syenite. Systematic SHRIMP or LA-ICP-MS zircon U-Pb analyses of 15 representative samples from various phases of the Gejiu complex yielded Late Cretaceous ages of 78-85 Ma. Based on their mineralogical, geochemical and Sr-Nd-Hf isotope characteristics, these rocks are categorized into three groups: felsic rocks, alkaline rocks and mafic rocks. The felsic rock group includes the equigranular and porphyritic granites. Geochemical characteristics include high SiO2 contents, enrichment in Rb, Th, U, Nb, Ta, Nd and Hf and depletion in Ba, K, Sr, P, Eu and Ti compared to primitive mantle. REE patterns feature slight LREE enrichment with pronounced negative Eu anomalies. Geochemical data and Sr-, Nd- and Hf-isotopic compositions indicate that the felsic rocks were probably generated by partial melting of crustal source rocks with a minor input from mantle materials. The mafic rocks (gabbro and mafic microgranular enclaves) have distinct geochemical and isotopic features consistent with derivation from an enriched mantle source, with variable degrees of mixing with crustal-derived magmas. Strontium-, Nd- and Hf-isotopic compositions of the alkaline rocks are similar with those of the mafic rocks, suggesting that they have a similar source. Nevertheless, petrological and geochemical characteristics of these rocks indicate that they experienced extensive crystal fractionation and limited crustal contamination. Based on the emplacement of the gabbro-mafic microgranular enclaves-syenite-granites in the Gejiu district, together with contemporaneous geological events in other parts of the western Cathaysia block, we suggest that a widespread extension-related magmatic episode affected the entire region in the late Cretaceous, possibly as a result of lithospheric thinning, basaltic underplating and associated crustal melting. (C) 2013 Elsevier B.V. All rights reserved.
学科主题	火成岩岩石学
WOS关键词	NATURAL REFERENCE MATERIAL ; PLASMA-MASS SPECTROMETRY ; A-TYPE GRANITES ; U-PB ; GEOCHEMICAL CONSTRAINTS ; SE CHINA ; LASER-ABLATION ; TECTONIC ; SIGNIFICANCE ; MAGMATIC PROCESSES ; MAFIC INTRUSIONS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000322430800014
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40020]
专题	中国地质科学院矿产资源研究所
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Resources, MLR Lab Metallogeny & Mineral Assessment, Beijing 100037, Peoples R China. 2.China Univ Geosci, Fac Earth Sci & Mineral Resources, Beijing 100083, Peoples R China. 3.James Cook Univ, Sch Earth & Environm Sci, Townsville, Qld 4811, Australia.
推荐引用方式 GB/T 7714	Cheng, Yanbo,Mao, Jingwen,Spandler, Carl. Petrogenesis and geodynamic implications of the Gejiu igneous complex in;the western Cathaysia block, South China[J]. LITHOS,2013,175:213-229.
APA	Cheng, Yanbo,Mao, Jingwen,&Spandler, Carl.(2013).Petrogenesis and geodynamic implications of the Gejiu igneous complex in;the western Cathaysia block, South China.LITHOS,175,213-229.
MLA	Cheng, Yanbo,et al."Petrogenesis and geodynamic implications of the Gejiu igneous complex in;the western Cathaysia block, South China".LITHOS 175(2013):213-229.