Decoupling of Hf-Nd Isotopes in Challenger Deep Sediments, Mariana Trench: Implications for Sedimentary Hf and Nd Recycling in Subduction Zones

doi:10.1029/2021JB021641

CORC > 深海科学与工程研究所 > 中国科学院深海科学与工程研究所 > 深海科学研究部 > 深海地球物理与资源研究室

	Decoupling of Hf-Nd Isotopes in Challenger Deep Sediments, Mariana Trench: Implications for Sedimentary Hf and Nd Recycling in Subduction Zones
	Pang, Chong-Jin 2; Tian, Liyan 1; Wang, Xuan-Ce 3,4; Zhang, Hanyu 1; Wen, Shu-Nv 2; Krapez, Bryan 2; Liu, Wen-Jing 5,6; Liu, Zhi-Xing 4; Wu, Tao 7
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2021-06-01
卷号	126 期号:6 页码:20
关键词	Hf-Nd isotopic decoupling oceanic hydrodynamic mineral sorting sedimentary Hf-Nd recycling density-current deposits Challenger Deep subduction factory
ISSN号	2169-9313
DOI	10.1029/2021JB021641
英文摘要	Decoupling between Hf and Nd isotopes in trench sediments is an important way to produce, via subduction-related recycling, the mantle chemical heterogeneity that is evident in many arc-related magmas. Sediments collected from >7,000 m water depths on the southern and northern slopes of the Challenger Deep were analyzed to understand the factors controlling the variation in Hf and Nd isotopic compositions. These sediments were transported to both flanks of the Challenger Deep by synchronous density currents. All sediment samples show positive e(Hf) values and negative e(Nd) values, mostly plotting above the seawater and terrestrial arrays in Hf-Nd isotope space. Hafnium isotopic compositions in each depositional unit vary (high up to 9.2 e(Hf) units) from lower, coarse-grained laminae to upper, fine-grained graded intervals, showing a good correspondence between e(Hf) values and lamination within depositional units. Such variations are explained by the concentration of Fe-Mn oxyhydroxide-bearing clays in the upper graded intervals, whereas diatom fragments and arc-volcanic detritus are preferentially sorted into lower laminae. These findings demonstrate that the decoupling of Hf-Nd isotopes in trench sediments is not only linked to the nature of provenance but also to hydrodynamic sorting processes during sediment transport. Our results suggest that geographical and stratigraphic variations in sedimentary components (resedimented density-current deposits vs. oceanic pelagites), as well as overall grain size, of the subduction wedge can complicate Hf-Nd isotopic decoupling in resulting arc magmas.
资助项目	National Natural Science Foundation of China[41973014] ; National Natural Science Foundation of China[41876044] ; Research Start-up Project for Introduced Talent of Yunnan University[20190043] ; Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0202] ; Youth Innovation Promotion Association CAS[2019067]
WOS关键词	REFERENCE MATERIALS BCR-1 ; IZU-BONIN-MARIANA ; WESTERN PACIFIC ; SM-ND ; SEA SEDIMENTS ; LU-HF ; ELEMENT ; ARC ; GEOCHEMISTRY ; PROVENANCE
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000665206200047
资助机构	National Natural Science Foundation of China ; Research Start-up Project for Introduced Talent of Yunnan University ; Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) ; Youth Innovation Promotion Association CAS
内容类型	期刊论文
源URL	[http://ir.idsse.ac.cn/handle/183446/8739]
专题	深海科学研究部_深海地球物理与资源研究室
通讯作者	Pang, Chong-Jin; Wang, Xuan-Ce
作者单位	1.Chinese Acad Sci, Inst Deep Sea Sci & Engn, Sanya, Peoples R China 2.Guilin Univ Technol, Guangxi Key Lab Hidden Metall Ore Deposits Explor, Guilin, Peoples R China 3.Yunnan Univ, Sch Earth Sci, Kunming, Yunnan, Peoples R China 4.Changan Univ, Sch Earth Sci & Resources, Xian, Peoples R China 5.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China 6.CAS Ctr Excellence Life & Paleoenvironm, Beijing, Peoples R China 7.Zhejiang Univ, Ocean Coll, Zhoushan, Peoples R China
推荐引用方式 GB/T 7714	Pang, Chong-Jin,Tian, Liyan,Wang, Xuan-Ce,et al. Decoupling of Hf-Nd Isotopes in Challenger Deep Sediments, Mariana Trench: Implications for Sedimentary Hf and Nd Recycling in Subduction Zones[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2021,126(6):20.
APA	Pang, Chong-Jin.,Tian, Liyan.,Wang, Xuan-Ce.,Zhang, Hanyu.,Wen, Shu-Nv.,...&Wu, Tao.(2021).Decoupling of Hf-Nd Isotopes in Challenger Deep Sediments, Mariana Trench: Implications for Sedimentary Hf and Nd Recycling in Subduction Zones.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,126(6),20.
MLA	Pang, Chong-Jin,et al."Decoupling of Hf-Nd Isotopes in Challenger Deep Sediments, Mariana Trench: Implications for Sedimentary Hf and Nd Recycling in Subduction Zones".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 126.6(2021):20.