ITPCAS OpenIR  > 图书馆
Chromium speciation and its stable isotopic signature in the dolomite-terra rossa weathering system
Feng, JL (Feng, Jin-Liang)1; Li, CF (Li, Chao-Feng)2,3
Source PublicationGEODERMA

We present the results of a study of chromium (Cr) content, Cr speciation and its stable isotope composition in a terra rossa weathering profile, which includes ferromanganese concretions (FMCs) and gibbsite spots, developed on dolomite in the Yunnan-Guizhou Plateau in south central China. Sequential extraction results show that the Cr in all samples is present mainly within the residual fraction and oxidizable fraction, and that the Cr content of the exchangeable fraction and reducible fraction is very low. The significantly high Cr content (mean of 21.0 ppm) of the oxidizable fraction is a potential environmental hazard. The Cr in the terra rossa and gibbsite spots exhibits absolute accumulation throughout the profile; correspondingly, the FMCs are significantly enriched in most trace elements, except for Cr. Re-oxidation of Cr(III) to soluble Cr(VI) by MnO2 is likely responsible for the relative depletion of Cr in the FMCs. In the bulk dolomite, the delta Cr-53 values of the carbonate component and detrital component are 0.447 parts per thousand and - 0.437 parts per thousand, respectively. The delta Cr-53 signal in both fractions is heterogeneous, while both delta Cr-53 signals are significantly different from that of bulk silicate Earth (BSE; -0.124 +/- 0.101 parts per thousand). Our results provide a proof of concept that the allogenic Cr-isotopic composition of terrigenous minerals in carbonate rocks, can provide new insights into paleo-terrestrial oxidative weathering. Overall, the terra rossa is characterized by the enrichment of heavy Cr isotopes compared to the detrital component of dolomite. Hence, the isotopic signature of Cr does not support the idea that the detrital component in dolomite is the sole parent material of the terra rossa. The absolute accumulation of Cr and heavy Cr isotope enrichment in terra rossa indicate that the extraneous input of dissolved Cr(VI) with a heavy isotopic signature occurred during dolomite weathering and terra rossa formation.

Subject AreaEnvironmental Sciences
WOS IDWOS:000457665000010
Indexed BySCI
KeywordYunnan-guizhou Plateau Neoproterozoic Ghaub Glaciation Cr-isotope Trace-elements Hexavalent Chromium Ferromanganese Concretions Chromate Adsorption Cr(Vi) Reduction Heavy-metals Otavi Group
WOS Research AreaAgriculture
WOS SubjectSoil Science
Cooperation Status国内
Citation statistics
Document Type期刊论文
Corresponding AuthorFeng, JL (Feng, Jin-Liang); Li, CF (Li, Chao-Feng)
Affiliation1.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Tibetan Environm Changes & Land Surface P, Beijing 100101, Peoples R China;
2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China;
3.Chinese Acad Sci, Inst Earth Sci, Beijing 100029, Peoples R China.
Recommended Citation
GB/T 7714
Feng, JL ,Li, CF . Chromium speciation and its stable isotopic signature in the dolomite-terra rossa weathering system[J]. GEODERMA,2019,339(0):106-114.
APA Feng, JL ,&Li, CF .(2019).Chromium speciation and its stable isotopic signature in the dolomite-terra rossa weathering system.GEODERMA,339(0),106-114.
MLA Feng, JL ,et al."Chromium speciation and its stable isotopic signature in the dolomite-terra rossa weathering system".GEODERMA 339.0(2019):106-114.
Files in This Item:
File Name/Size DocType Version Access License
2019331.pdf(1752KB)期刊论文出版稿开放获取CC BY-NC-SAView Application Full Text
Related Services
Recommend this item
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[Feng, JL (Feng, Jin-Liang)]'s Articles
[Li, CF (Li, Chao-Feng)]'s Articles
Baidu academic
Similar articles in Baidu academic
[Feng, JL (Feng, Jin-Liang)]'s Articles
[Li, CF (Li, Chao-Feng)]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[Feng, JL (Feng, Jin-Liang)]'s Articles
[Li, CF (Li, Chao-Feng)]'s Articles
Terms of Use
No data!
Social Bookmark/Share
File name: 2019331.pdf
Format: Adobe PDF
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.