Response to the Neoproterozoic mantle plume(s) on the western margin of Rodinia: Preliminary evidence from the Malagasy Shield

IMR OpenIR

	Response to the Neoproterozoic mantle plume(s) on the western margin of Rodinia: Preliminary evidence from the Malagasy Shield
其他题名	Response to the Neoproterozoic mantle plume(s) on the western margin of Rodinia:Preliminary evidence from the Malagasy Shield
	Zhou JiuLong 1; Shao Shua 1; Wu DaTian 1; Luo ZhaoHua 1; Shao JianBo 3; Wang KuiLiang 3; Zhao YuanDong 3; Rasoamalala Vololonirina 4
	2014
发表期刊	ACTA PETROLOGICA SINICA
ISSN	1000-0569
卷号	30 期号:11 页码:3366-3374
摘要	It remains open to debate whether there was an extensive Andean-type arc on the western margin of the Rodinia supercontinent. Madagascar is an ideal locality to answer this question because of its western marginal position in Rodinia reconstruction as well as widespread Neoproterozoic intrusions throughout the Archean basement. Partly owing to the rare exposure of mafic component, these intrusive rocks have been previously regarded as subduction-related origin. However, there are lots of gabbroic rocks exposed near the Alaotra Lake area. LA-ICP-MS zircon U-Pb dating reveals that a typical intrusion crystallized from 798Ma to 778Ma (at maximum uncertainty). Together with other intrusive rocks, these gabbros thus constitute a hi-modal intrusive suite in the Malagasy Shield, implying an intra-continental rifling setting. Based on this, we re-examine the previous geochemical data and find that the mafic component indeed exhibits K-enriched feature and tholeiitic trend with local Fe-Ti-V mineralization, while the felsic component shows the ferroan, metaluminous to peraluminous, and alkali-calcic to calc-alkalic compositions of A-type granites, which is further confirmed by their high K2O/Na2O and Ga/Al ratios and high-field-strength-element contents. Both geochemical signatures are consistent with an intra-continental rifting rather than continental arc regime. Our preliminary results, coupled with the knowledge of the regional geological evolution, allow us to speculate that this bi-modal intrusive suite in Madagascar is most likely a response to the Neoproterozoic mantle plume (s) on the western margin of the Rodinia supercontinent.
关键词	NORTH-CENTRAL MADAGASCAR U-PB GEOCHRONOLOGY VOLCANIC-ROCKS ZIRCON AGES BREAK-UP NW INDIA ICP-MS GRANITOIDS ARC GEOCHEMISTRY Bi-modal intrusive suite Tholeiitic trend A-type granite Mantle plume Neoproterozoic Madagascar
收录类别	CSCD
语种	英语
CSCD记录号	CSCD:5299832
引用统计	被引频次：2[CSCD] [CSCD记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/145062
专题	中国科学院金属研究所
作者单位	1.China University Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China 2.China Aero Geophys Survey & Remote Sensing Ctr La, Beijing 100083, Peoples R China 3.中国科学院金属研究所 4.Minist Mines, Directorate Geol, Antananarivo 101, Madagascar
推荐引用方式 GB/T 7714	Zhou JiuLong,Shao Shua,Wu DaTian,et al. Response to the Neoproterozoic mantle plume(s) on the western margin of Rodinia: Preliminary evidence from the Malagasy Shield[J]. ACTA PETROLOGICA SINICA,2014,30(11):3366-3374.
APA	Zhou JiuLong.,Shao Shua.,Wu DaTian.,Luo ZhaoHua.,Shao JianBo.,...&Rasoamalala Vololonirina.(2014).Response to the Neoproterozoic mantle plume(s) on the western margin of Rodinia: Preliminary evidence from the Malagasy Shield.ACTA PETROLOGICA SINICA,30(11),3366-3374.
MLA	Zhou JiuLong,et al."Response to the Neoproterozoic mantle plume(s) on the western margin of Rodinia: Preliminary evidence from the Malagasy Shield".ACTA PETROLOGICA SINICA 30.11(2014):3366-3374.