NIGPAS OpenIR
Deep-water dissolved iron cycling and reservoir size across the Ediacaran-Cambrian transition
Xiang, Lei1,2; Schoepfer, Shane D.3; Zhang, Hua1,2; Chen, Zhen-wu4; Cao, Chang-qun1,2; Shen, Shu-zhong5
2020-05-20
Source PublicationCHEMICAL GEOLOGY
ISSN0009-2541
Volume541Pages:9
Abstract

The majority of the deep ocean was likely under ferruginous conditions during the first four billion years of Earth's history. As the atmosphere was gradually oxygenated, the sources, sinks, redox cycling, and reservoir size of dissolved iron in the deep ocean are likely to have changed dramatically. Whether deep water was thoroughly oxygenated by the time of the Ediacaran-Cambrian transition, and the relationship of this oxygenation to the Cambrian explosion, remains debated. To explore the degree of oceanic oxygenation and its effect on Cambrian explosion, we measured the iron isotopic composition (delta Fe-56) of bulk rock (i.e., cherts and mudstones/shales) through the Piyuancun and Hetang formations, using samples collected from the Chunye-1 core, on the Lower Yangtze Block in western Zhejiang. The limited variation in delta Fe-56 values (< 0.7 parts per thousand) and low Fe-T/Al ratios (< 0.77) in euxinic samples show that the deep-water Fe2+ reservoir was quite limited, and likely similar to that of the modern ocean, during the latest Ediacaran and Cambrian Stages 1-3. Iron isotope results, combined with published data from sections on the Middle and Upper Yangtze Block, record a general decline in seawater delta Fe-56 values from > 0.55 parts per thousand during the end-Ediacaran and Cambrian Stages 1-3 to < 0 parts per thousand during Cambrian Stage 4. Seawater delta Fe-56 values in the lower and middle Hetang Formation range between 0 and 0.2 parts per thousand, suggesting that the riverine dissolved and suspended flux and/or aeolian dust was the predominant source of highly reactive iron to the deep basin. Positive deep-water delta Fe-56 values, above 0.55 parts per thousand during the terminal Ediacaran and Cambrian Stages 1-3, likely reflect a basin where pyritization, rather than oxidation, was the predominant sink for deep-water ferrous Fe. Thus, we infer that only the shallow water was sufficiently oxygenated to support complex metazoans and the evolutions of skeletons, and that atmospheric oxygen levels were not high enough to directly oxygenate deep water environments during the Cambrian explosion.

KeywordHetang Formation Iron isotope Oceanic dissolved iron reservoir Oceanic iron cycle Cambrian explosion
DOI10.1016/j.chemgeo.2020.119575
Indexed BySCI
Language英语
WOS KeywordFE ISOTOPE FRACTIONATION ; SOUTH CHINA ; FERRUGINOUS CONDITIONS ; ATMOSPHERIC OXYGEN ; PALEOREDOX PROXIES ; YANGTZE PLATFORM ; REDOX CONDITIONS ; AQUEOUS FE(II) ; EARLY HISTORY ; NANHUA BASIN
Funding ProjectStrategic Priority Research Program (B) of the Chinese Academy of Sciences[XDB26000000] ; Strategic Priority Research Program (B) of the Chinese Academy of Sciences[18000000] ; National Natural Science Foundation of China[41502023] ; National Natural Science Foundation of China[41273081]
WOS Research AreaGeochemistry & Geophysics
WOS SubjectGeochemistry & Geophysics
WOS IDWOS:000537202100008
Funding OrganizationStrategic Priority Research Program (B) of the Chinese Academy of Sciences ; National Natural Science Foundation of China
PublisherELSEVIER
Citation statistics
Document Type期刊论文
Identifierhttp://ir.nigpas.ac.cn/handle/332004/31934
Collection中国科学院南京地质古生物研究所
Corresponding AuthorXiang, Lei
Affiliation1.Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, State Key Lab Palaeobiol & Stratig, 39 East Beijing Rd, Nanjing 210008, Peoples R China
2.Chinese Acad Sci, Ctr Excellence Life & Paleoenvironm, 39 East Beijing Rd, Nanjing 210008, Peoples R China
3.Western Carolina Univ, Dept Geosci & Nat Resources, 1 Univ Way, Cullowhee, NC 28779 USA
4.Univ Sci & Technol China, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Anhui, Peoples R China
5.Nanjing Univ, Sch Earth Sci & Engn, 163 Xianlin Ave, Nanjing 210023, Peoples R China
First Author AffilicationNanjing Institute of Geology and Palaeonotology,CAS
Corresponding Author AffilicationNanjing Institute of Geology and Palaeonotology,CAS
Recommended Citation
GB/T 7714
Xiang, Lei,Schoepfer, Shane D.,Zhang, Hua,et al. Deep-water dissolved iron cycling and reservoir size across the Ediacaran-Cambrian transition[J]. CHEMICAL GEOLOGY,2020,541:9.
APA Xiang, Lei,Schoepfer, Shane D.,Zhang, Hua,Chen, Zhen-wu,Cao, Chang-qun,&Shen, Shu-zhong.(2020).Deep-water dissolved iron cycling and reservoir size across the Ediacaran-Cambrian transition.CHEMICAL GEOLOGY,541,9.
MLA Xiang, Lei,et al."Deep-water dissolved iron cycling and reservoir size across the Ediacaran-Cambrian transition".CHEMICAL GEOLOGY 541(2020):9.
Files in This Item:
File Name/Size DocType Version Access License
Deep-water dissolved(968KB)期刊论文出版稿开放获取CC BY-NC-SA
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[Xiang, Lei]'s Articles
[Schoepfer, Shane D.]'s Articles
[Zhang, Hua]'s Articles
Baidu academic
Similar articles in Baidu academic
[Xiang, Lei]'s Articles
[Schoepfer, Shane D.]'s Articles
[Zhang, Hua]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[Xiang, Lei]'s Articles
[Schoepfer, Shane D.]'s Articles
[Zhang, Hua]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

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