Genesis of Intermediate and Silicic Arc Magmas Constrained by Nb/Ta Fractionation

doi:10.1029/2020JB020708

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Genesis of Intermediate and Silicic Arc Magmas Constrained by Nb/Ta Fractionation
	Chen, Wei 3,4; Zhang, Guoliang 1,2,3,4; Ruan, Mengfei 5; Wang, Shuai 3,4; Xiong, Xiaolin 5
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2021-03-01
卷号	126 期号:3 页码:15
关键词	amphibole arc magma continental crust Nb Ta differentiation rutile
ISSN号	2169-9313
DOI	10.1029/2020JB020708
通讯作者	Zhang, Guoliang(zhangguoliang@qdio.ac.cn)
英文摘要	Resolving the geochemical discrepancies in Nb/Ta between the bulk continental crust and its parental mantle melts can provide insights into the processes by which basaltic magmas differentiated into the felsic crust. Deep-seated garnet pyroxenite cumulates (i.e., arclogite) have high Nb/Ta values due to the presence of high Nb/Ta-rutile. For this reason, rutile-bearing arclogites having Nb-rich composition were proposed to complement the low Nb/Ta nature of the continental crust and evolved arc magmas, that is to say, continental arc magma evolution dominantly occurred in the stability field of garnet. However, this suggestion is challenged by the incomplete understanding of the role of rutile in the Nb/Ta fractionation during arc magma evolution due to insufficient partitioning data at low temperatures (T <= 1,000 degrees C). Here, we determined Nb and Ta partitioning ratios in rutile-felsic melt systems at 2.0 GPa, 850-1,000 degrees C and similar to 4-20 wt.% H2O. Our results confirm that equilibrium crystallization of rutile with respect to Nb and Ta will not impart lower Nb/Ta values to any derivative liquids, whereas diffusive fractionation of Nb/Ta in siliceous melts during the growth of rutile can reduce Nb/Ta ratios in melts. However, a positive correlation between Nb/Ta and Dy/Yb for mature continental arc magmas, incipient continental arc magmas, island arc magmas, and global arc magmas indicates that amphibole rather than rutile-bearing arclogite was responsible for causing low Nb/Ta ratios of many evolved intermediate rocks. Accordingly, the chemical differentiation from primary basaltic to average andesitic compositions of the continental crust mainly occurred in the stability field of amphibole.
资助项目	National Key Research and Development Program of China[2018YFA0702704] ; National Natural Science Foundation of China (NSFC)[91858206] ; National Natural Science Foundation of China (NSFC)[92062222] ; National Natural Science Foundation of China (NSFC)[42003049] ; Key Research Project of Frontier Science of the Chinese Academy of Sciences[QYZDJ-SSW-DQC012] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA22050101] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB42020302] ; Taishan Scholars Program of Shandong Province[tsqn201909157]
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000638091600006
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/170516]
专题	海洋研究所_海洋地质与环境重点实验室
通讯作者	Zhang, Guoliang
作者单位	1.Chinese Acad Sci, Ctr Ocean Mega Sci, Qingdao, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao, Peoples R China 3.Chinese Acad Sci, Key Lab Marine Geol & Environm, Inst Oceanol, Qingdao, Peoples R China 4.Chinese Acad Sci, Ctr Deep Sea Res, Qingdao, Peoples R China 5.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou, Peoples R China
推荐引用方式 GB/T 7714	Chen, Wei,Zhang, Guoliang,Ruan, Mengfei,et al. Genesis of Intermediate and Silicic Arc Magmas Constrained by Nb/Ta Fractionation[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2021,126(3):15.
APA	Chen, Wei,Zhang, Guoliang,Ruan, Mengfei,Wang, Shuai,&Xiong, Xiaolin.(2021).Genesis of Intermediate and Silicic Arc Magmas Constrained by Nb/Ta Fractionation.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,126(3),15.
MLA	Chen, Wei,et al."Genesis of Intermediate and Silicic Arc Magmas Constrained by Nb/Ta Fractionation".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 126.3(2021):15.