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DOI	10.1016/j.chemgeo.2021.120284
	Evidence for extreme Sm-Nd fractionation during chemical weathering
	Feng, Jin-Liang; Zhang, Ji-Feng; Gao, Shao-Peng; Li, Chao-Feng; Ju, Jian-Ting; Liu, Xiao-Ming; Pei, Le-Le; Wang, Kun-Ying
通讯作者	Feng, JL (通讯作者)
发表日期	2021
ISSN	0009-2541
EISSN	1872-6836
卷号	577
英文摘要	During subaerial chemical weathering, submarine weathering and other intracrustal processes, Sm-Nd chemical fractionation remains uncertain, while a little is known about the conditions, scale and magnitude, specific processes and actual mechanism for possible Sm-Nd fractionation. Here, an in situ terra rossa weathering profile developed on dolostone is chosen for the study. Based on sequential extraction experiments and measurements of the mineral and geochemical compositions including Sr-Nd isotopic compositions, we suggest that subaerial chemical weathering not only leads to considerable Sm-Nd mobilization, redistribution and secondary enrichment, but also gives rise to extreme Sm-Nd fractionation, apparent 143Nd isotope homogenization, nearly complete resetting of the 147Sm-143Nd isotope system, anomalous initial 143Nd/144Nd ratios, and meaningless 143Nd model age (TDM) for weathering products. We found that the lanthanide tetrad effect, rather than mineralogical control, is responsible for the observed substantial Sm-Nd fractionation and for the other rare earth element fractionation. Under domination of the lanthanide tetrad effect, the mobility of Sm is preferential to that of Nd during their migration in the form of dissolved organic complexes. Our results also illustrate that resetting of the 147Sm-143Nd isotope system in weathering products is controlled by the combined effect of the extraneous dissolved Sm-Nd input and additional Sm-Nd fractionation. Finally, we argue that similar scenarios may occur in submarine weathering, diagenesis and other geological processes.
关键词	RARE-EARTH-ELEMENTS ROSSA OVERLYING DOLOMITE YUNNAN-GUIZHOU PLATEAU TERRA ROSSA TRACE-ELEMENTS FERROMANGANESE CONCRETIONS ISOTOPIC SYSTEMATICS CONTINENTAL-CRUST REE FRACTIONATION BULK COMPOSITION
英文关键词	Dolostone; Terra rossa; Chemical weathering; Sm-Nd fractionation; Sm-Nd isotope system; Lanthanide tetrad effect
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000662690400001
来源期刊	CHEMICAL GEOLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/260175
推荐引用方式 GB/T 7714	Feng, Jin-Liang,Zhang, Ji-Feng,Gao, Shao-Peng,et al. Evidence for extreme Sm-Nd fractionation during chemical weathering[J]. 中国科学院青藏高原研究所,2021,577.
APA	Feng, Jin-Liang.,Zhang, Ji-Feng.,Gao, Shao-Peng.,Li, Chao-Feng.,Ju, Jian-Ting.,...&Wang, Kun-Ying.(2021).Evidence for extreme Sm-Nd fractionation during chemical weathering.CHEMICAL GEOLOGY,577.
MLA	Feng, Jin-Liang,et al."Evidence for extreme Sm-Nd fractionation during chemical weathering".CHEMICAL GEOLOGY 577(2021).