Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera

doi:10.1016/j.chemgeo.2024.121954

	Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera
	Huang, Yi 1; Colin, Christophe 1; Liu, Zhifei 2; Joffrey, Bertaz 1,2; Dapoigny, Arnaud 3; Douville, Eric 3; Yu, Zhaojie 4; Lin, Andrew Tien -Shun 5
	2024-03-20
发表期刊	CHEMICAL GEOLOGY
ISSN	0009-2541
卷号	648 页码:12
通讯作者	Colin, Christophe([email protected])
摘要	Neodymium isotopic compositions (eNd) in the marginal sea is influenced by the ocean circulations as well as the lithogenic input from continents, but their relative contributions and the impact of detrital sediments are not well constrained. In this study, Nd isotopic compositions of mixed planktonic foraminifera species and carbonate-free fraction of sediment from two cores collected at 1250-1350 m water depth in the southwestern (core MD01-2393) and northeastern (core MD18-3569) South China Sea (SCS) have been investigated in order to constrain the relative contributions of lithogenic Nd inputs from large Asian rivers and hydrological variations at intermediate depth in the SCS. The foraminiferal eNd values of both cores (-7.3 +/- 0.2 to -5.8 +/- 0.2 for core MD18-3569 and - 8.1 +/- 0.2 to -7.2 +/- 0.2 for core MD01-2393) indicate strong modifications of the initial eNd of the North Pacific Intermediate Water (NPIW) (eNd of -4) flowing into the SCS by unradiogenic sediments (-13 to -11) from large Asian rivers. The foraminiferal eNd record of core MD01-2393 displays significantly unradiogenic values from 18 to 8 cal kyr BP which are associated with intensification of monsoon rainfall and river input of detrital material characterized by strongly altered minerals (high illite chemical index and kaolinite/illite ratio) deriving from tropical plain soils of the Mekong River basin. We suggest here that pedogenetic minerals from tropical plain soils are more efficient in terms of Nd exchange with the seawater than primary minerals produced by intense physical erosion during the glacial period. In contrast, the foraminiferal eNd record for the northern core MD18-3569 is characterized by radiogenic eNd values from 18 to 12 cal kyr BP; these values have been linked to an increased intrusion of radiogenic glacial NPIW to the northern SCS and greater ventilation of water masses (deduced from Delta 14C) in the northern deep basin of the SCS compared to the southern one. This time interval is associated with newly formed NPIW in the subarctic Pacific Ocean beginning at about 18 cal kyr BP. Overall, our results indicate that the state of chemical weathering of sediment delivered by rivers is the main factor controlling the detrital modification of past seawater eNd distributions in the marginal sea of the SCS.
关键词	Foraminiferal eNd Weathering River discharge Paleohydrology East Asian Summer Monsoon South China Sea
DOI	10.1016/j.chemgeo.2024.121954
收录类别	SCI
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001173137300001
出版者	ELSEVIER
WOS关键词	EAST-ASIAN MONSOON ; DEEP-WATER CIRCULATION ; PACIFIC-OCEAN ; INDIAN-OCEAN ; AUTHIGENIC PHASES ; NORTH PACIFIC ; GEOCHEMICAL INVESTIGATIONS ; FLUVIAL SEDIMENTS ; SURFACE SEDIMENTS ; TIBETAN PLATEAU
引用统计
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/184873
专题	海洋环境腐蚀与生物污损重点实验室
通讯作者	Colin, Christophe
作者单位	1.Univ Paris Saclay, CNRS, GEOPS, F-91405 Orsay, France 2.Tongji Univ, State Key Lab Marine Geol, Shanghai, Peoples R China 3.Univ Paris Saclay, Lab Sci Climat & Environm, LSCE, IPSL,CNRS,UVSQ, F-91191 Gif sur yvette, France 4.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 5.Natl Cent Univ, Dept Earth Sci, Jhongli 32001, Taiwan
推荐引用方式 GB/T 7714	Huang, Yi,Colin, Christophe,Liu, Zhifei,et al. Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera[J]. CHEMICAL GEOLOGY,2024,648:12.
APA	Huang, Yi.,Colin, Christophe.,Liu, Zhifei.,Joffrey, Bertaz.,Dapoigny, Arnaud.,...&Lin, Andrew Tien -Shun.(2024).Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera.CHEMICAL GEOLOGY,648,12.
MLA	Huang, Yi,et al."Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera".CHEMICAL GEOLOGY 648(2024):12.