Recycling of subducted carbonates: Formation of the Taohuala Mountain carbonatite, North China Craton

doi:10.1016/j.chemgeo.2017.10.039

CORC > 海洋研究所 > 中国科学院海洋研究所 > 深海极端环境与生命过程研究中心

	Recycling of subducted carbonates: Formation of the Taohuala Mountain carbonatite, North China Craton
	Xue, Shuo 1,2,6; Ling, Ming-Xing 1,5; Liu, Yu-Long 2; Sun, Weidong3,4,5
刊名	CHEMICAL GEOLOGY
	2018-02-05
卷号	478 页码:89-101
关键词	Taohuala Mountain North China Craton (NCC) Carbonatite Earth's carbon cycle Subduction
ISSN号	0009-2541
DOI	10.1016/j.chemgeo.2017.10.039
通讯作者	Ling, Ming-Xing(mxling@gig.ac.cn) ; Liu, Yu-Long(ylliu@gig.ac.cn)
英文摘要	Carbonatitic magmatism plays a significant role in Earth's carbon cycle, which is also a lithoprobe of crust-mantle interaction, mantle metasomatism and partial melting. Due to different mineral assemblages and geochemical compositions, and diverse tectonic settings, the origin of carbonatite has long been debated. At subduction zones, sediments (including carbonates) are subducted into the mantle with the downgoing oceanic slab. However, the detailed mechanism of how subducted carbonates contribute to carbonatitic magmatism remains unclear. Here we present geochronological, geochemical and isotopic study on the Taohuala Mountain carbonatite at the southern margin of the Alxa Block, North China Craton. The classification of carbonatite from the Taohuala Mountain relies strongly on the observations of obvious intrusion contact relationships and flow structures in field outcrop. The Taohuala Mountain carbonatite has SiO2 ranging from 2.37 wt.% to 11.45 wt%, high CaO (45.93-53.86 wt%) and low MgO (0.51-4.39 wt%), and is characterized by enrichment of LILE (Ba, Sr), depletion of HFSE (Nb, Ta, Zr, Hf), and slightly negative Ce and Eu anomalies. Carbonates in the samples have high Sr-87/Sr-86 (0.70686-0.70694) and low Nd-143/Nd-144 (0.511635-0.511924). Remarkably, the highly fractionated delta O-18(VSMOW) (11.83-25.92%) indicates components of both sedimentary and mantle origin. Detailed zircon in situ U-Pb dating and oxygen isotope analysis exhibit contrast ages and delta O-18(VSMOW) from core to rim, i.e., old ages (mainly > 800 Ma), high Th/U (mainly > 0.5) and low delta O-18(VSMOW) (6.37-11.44%) in cores (inherited), whereas young ages (similar to 400 Ma), low Th/U (mainly < 0.01) and high delta O-18(VSMOW) (20.04-24.54%) in rims, suggesting that the Taohuala Mountain carbonatite may have been generated from melting of subducted sedimentary carbonates. Considering all these evidences, and that the collision along Qilian Mountains was older than the carbonatite, we propose that a large volume of sedimentary carbonates subducted and remained in the lithospheric mantle under the Alxa block during the closure of the Paleo-Qilian Ocean. Subsequently, the carbonatite was formed by melting of carbonates with minor contributions from the mantle during the breakoff or rollback of the Paleo-Asian oceanic slab.
资助项目	National Key R & D Program of China[2017YFC0602301] ; National Key R & D Program of China[2017YFC0602302] ; Guangdong Natural Science Funds[2014A030306032] ; Guangdong Natural Science Funds[2015TQ01Z611] ; Natural Science Foundation of China[41421062] ; Youth Innovation Promotion Association CAS[2016315]
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000422753100008
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/157822]
专题	海洋研究所_深海极端环境与生命过程研究中心
通讯作者	Ling, Ming-Xing; Liu, Yu-Long
作者单位	1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China 2.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny, Guangzhou 510640, Guangdong, Peoples R China 3.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Peoples R China 4.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China 5.Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 6.Univ Chinese Acad Sci, Beijing 100094, Peoples R China
推荐引用方式 GB/T 7714	Xue, Shuo,Ling, Ming-Xing,Liu, Yu-Long,et al. Recycling of subducted carbonates: Formation of the Taohuala Mountain carbonatite, North China Craton[J]. CHEMICAL GEOLOGY,2018,478:89-101.
APA	Xue, Shuo,Ling, Ming-Xing,Liu, Yu-Long,&Sun, Weidong.(2018).Recycling of subducted carbonates: Formation of the Taohuala Mountain carbonatite, North China Craton.CHEMICAL GEOLOGY,478,89-101.
MLA	Xue, Shuo,et al."Recycling of subducted carbonates: Formation of the Taohuala Mountain carbonatite, North China Craton".CHEMICAL GEOLOGY 478(2018):89-101.