Geochronology and geochemistry of volcanic rocks from the Shaojiwa Formation and Xingzi Group, Lushan area, SE China: Implications for Neoproterozoic back-arc basin in the Yangtze Block

doi:10.1016/j.precamres.2013.09.016

	Geochronology and geochemistry of volcanic rocks from the Shaojiwa Formation and Xingzi Group, Lushan area, SE China: Implications for Neoproterozoic back-arc basin in the Yangtze Block
	Li, Longming 1,2; Lin, Shoufa 1,3; Xing, Guangfu 4; Davis, Donald W.5; Davis, William J.6; Xiao, Wenjiao 2; Yin, Changqing 1,2
刊名	PRECAMBRIAN RESEARCH
	2013-11-01
卷号	238 页码:1-17
关键词	Neoproterozoic Back Arc Basin Shaojiwa Formation Xingzi Group Jiangnan Orogen Yangtze Block
ISSN号	0301-9268
DOI	10.1016/j.precamres.2013.09.016
文献子类	Article
英文摘要	We present a systematic SHRIMP zircon U-Pb geochronological, geochemical and Nd isotopic study on the Shaojiwa basaltic-rhyolitic suite and Xingzi amphibolites in Lushan area, Yangtze Block. The protoliths of the amphibolites are low potassium tholeiitic basalts. Rhyolite and amphibolite yield SHRIMP zircon U-Pb ages of 828 +/- 6 Ma and 811 +/- 12 Ma respectively. These ages suggest that the Xingzi Group formed in the Neoproterozoic rather than Paleoproterozoic as previously suggested. The basalts from the Shaojiwa Formation have slightly positive epsilon(Nd)(t) values (0 to +0.7) and exhibit significant enrichment in LILE and LREE and strong depletion in HFSE, similar to arc-like volcanics. These geochemical and isotopic signatures suggest that the basalts might have been derived from a slightly depleted mantle source metasomatized by fluid/melt released from a newly subducted slab with high degree of mantle melting. The rhyolites exhibit similar Nd isotopic ratios as the associated basalts and show subparallel REE patterns which can be explained by fractional crystallization of the basalt magma. In contrast, the amphibolites from the Xingzi Group have relatively high epsilon(Nd)(t) values (+3.4 to +4.0) and are characterized by nearly flat REE distributions with slight LREE depletion and generally similar contents of moderately incompatible elements to those of the average N-MORB, but with relative enrichment in LILE, similar to the Mariana back-arc basin basalt (BABB). The precursor magma of the amphibolites might have been originated from an N-MORB source modified by slab-derived fluids with relatively low degree of mantle melting. The geochemical affinity to arc (or intra-continental BABB) of the Shaojiwa basalts and intra-oceanic BABE of the Xingzi amphibolites appears to support the development of a Neoproterozoic incipient to mature back-arc basin in the southeastern Yangtze Block during the 828 +/- 6 to 811 +/- 12 Ma period in response to the rollback of subducted slab. Widespread Neoproterozoic igneous rocks in the Jiangnan Orogen with ages older than 800 Ma most likely occurred in an arc-back-arc environment (C) 2013 Elsevier B.V. All rights reserved.
WOS关键词	SHRIMP U-PB ; JIANGNAN OROGENIC BELT ; GA CONTINENTAL-CRUST ; SOUTH CHINA ; TECTONIC EVOLUTION ; SUBDUCTION COMPONENTS ; CATHAYSIA BLOCKS ; TRACE-ELEMENT ; MANTLE PLUME ; ZIRCON GEOCHRONOLOGY
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000330818800001
资助机构	China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China Geology Survey(1212011121116) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; China NSFC(40725009) ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada ; Natural Sciences and Engineering Research Council of Canada
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/86390]
专题	中国科学院地质与地球物理研究所
通讯作者	Lin, Shoufa
作者单位	1.Univ Waterloo, Dept Earth & Environm Sci, Waterloo, ON N2L 3G1, Canada 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 3.Hefei Univ Technol, Sch Resources & Environm, Hefei 230026, Peoples R China 4.Nanjing Inst Geol & Mineral Resources, Nanjing 210016, Jiangsu, Peoples R China 5.Univ Toronto, Dept Geol, Toronto, ON M5S 3B1, Canada 6.Geol Survey Canada, Ottawa, ON K1A 0E8, Canada
推荐引用方式 GB/T 7714	Li, Longming,Lin, Shoufa,Xing, Guangfu,et al. Geochronology and geochemistry of volcanic rocks from the Shaojiwa Formation and Xingzi Group, Lushan area, SE China: Implications for Neoproterozoic back-arc basin in the Yangtze Block[J]. PRECAMBRIAN RESEARCH,2013,238:1-17.
APA	Li, Longming.,Lin, Shoufa.,Xing, Guangfu.,Davis, Donald W..,Davis, William J..,...&Yin, Changqing.(2013).Geochronology and geochemistry of volcanic rocks from the Shaojiwa Formation and Xingzi Group, Lushan area, SE China: Implications for Neoproterozoic back-arc basin in the Yangtze Block.PRECAMBRIAN RESEARCH,238,1-17.
MLA	Li, Longming,et al."Geochronology and geochemistry of volcanic rocks from the Shaojiwa Formation and Xingzi Group, Lushan area, SE China: Implications for Neoproterozoic back-arc basin in the Yangtze Block".PRECAMBRIAN RESEARCH 238(2013):1-17.