Petrogenesis of the 2115 Ma Haicheng mafic sills from the Eastern North China Craton: Implications for an intra-continental rifting

doi:10.1016/j.gr.2016.01.009

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 岩石圈演化国家重点实验室

	Petrogenesis of the 2115 Ma Haicheng mafic sills from the Eastern North China Craton: Implications for an intra-continental rifting
	Wang, Xinping 1,2; Peng, Peng 1; Wang, Chong 1,2; Yang, Shuyan 1,2
刊名	GONDWANA RESEARCH
	2016-11-01
卷号	39 页码:347-364
关键词	The Eastern North China Craton Haicheng Mafic Sills Paleoproterozoic Intra-continental Rifting
ISSN号	1342-937X
DOI	10.1016/j.gr.2016.01.009
文献子类	Article
英文摘要	The Rhyacian (2300-2050 Ma) is a special era of the Paleoproterozoic represented by large layered intrusions in many cratons. It is well known that there are widespread igneous events at similar to 2100Ma in the Eastern North China Craton; however, their tectonic environments are under debate: whether they were related to an intracontinental rifting or an arc/back-arc setting along a continental margin. These similar to 2100 Ma igneous events comprise several mafic dykes/sills, with some coeval A-type granites and volcanic events in several rifts; among them, the Haicheng mafic sills in the Liaohe rift are unique as their host rock, the Liaohe Group, bears the world's largest magnesium deposit. Most of the mafic sills are E-W-elongated at present coordinates. Exclusive of superimposition caused by deformation, the widths of the individuals are tens to hundreds of meters and the lengths are hundreds to thousands of meters. They have metamorphosed to an assemblage of plagioclase and hornblende, with minor quartz and accessory chlorite, epidote, apatite, ilmenite, and magnetite. However, relic gabbro and ophitic textures with mainly plagioclase and clinopyroxene are well-preserved. SIMS Pb-Pb dating on baddeleyites from one similar to 1000 m thick sill near Xialiulinzi village yields an average Pb-207/Pb-206 age of 2115 +/- 3Ma (n= 15, MSWD= 2.3), representing the timing of crystallization. SIMS U-Pb dating on zircon yields a similar forming age. They are tholeiitic in composition (MgO: 4.36-8.88 wt.%; SiO2: 45.76-53.39 wt.%), enriched in light rare earth elements ((La/Yb) N= 1.72-4.37) and large ion lithophile elements (i.e., Cs, Rb, Sr, and K) but depleted in high field strength elements (i.e., Nb, Ta, and Ti). These features were unlikely caused by crustal contamination during their emplacement, as there are little variations in Nb/La and Th/Nb. The rocks have experienced significant plagioclase-plus clinopyroxene-dominating fractional crystallization. Their enriched Sr-Nd isotope characteristics (Sr-87/(86)Srt = 0.703 similar to 0.705, epsilon Nd-t = -1.9 similar to 0.6) and trace element patterns indicate that their source(s) could be the ancient subcontinental lithospheric mantle; and this source is similar to those coeval sills from other parts of the craton. Their arc-like trace element features could be inherited from their source regions formed via a subduction process at the late Archean rather than at the middle-late Paleoproterozoic. These sill swarms, throughout the craton, might have developed in an integrated intra-continental rift system at similar to 2100 Ma. (C) 2016 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
WOS关键词	LIAO-JI BELT ; PB ZIRCON GEOCHRONOLOGY ; WHOLE-ROCK GEOCHEMISTRY ; PALEOPROTEROZOIC CRUSTAL EVOLUTION ; HIGH-PRESSURE GRANULITES ; LARGE IGNEOUS PROVINCE ; LU-HF ISOTOPES ; U-PB ; TECTONIC IMPLICATIONS ; TRACE-ELEMENT
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000397872900020
资助机构	NFSC Projects(2012CB416601) ; NFSC Projects(2012CB416601) ; NFSC(41322018) ; NFSC(41322018) ; NFSC Projects(2012CB416601) ; NFSC Projects(2012CB416601) ; NFSC(41322018) ; NFSC(41322018) ; NFSC Projects(2012CB416601) ; NFSC Projects(2012CB416601) ; NFSC(41322018) ; NFSC(41322018) ; NFSC Projects(2012CB416601) ; NFSC Projects(2012CB416601) ; NFSC(41322018) ; NFSC(41322018)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/52980]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者	Peng, Peng
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Wang, Xinping,Peng, Peng,Wang, Chong,et al. Petrogenesis of the 2115 Ma Haicheng mafic sills from the Eastern North China Craton: Implications for an intra-continental rifting[J]. GONDWANA RESEARCH,2016,39:347-364.
APA	Wang, Xinping,Peng, Peng,Wang, Chong,&Yang, Shuyan.(2016).Petrogenesis of the 2115 Ma Haicheng mafic sills from the Eastern North China Craton: Implications for an intra-continental rifting.GONDWANA RESEARCH,39,347-364.
MLA	Wang, Xinping,et al."Petrogenesis of the 2115 Ma Haicheng mafic sills from the Eastern North China Craton: Implications for an intra-continental rifting".GONDWANA RESEARCH 39(2016):347-364.