Publication Date:
2010-02-13
Description:
The Ediacaran Period (635 to 542 million years ago) was a time of fundamental environmental and evolutionary change, culminating in the first appearance of macroscopic animals. Here, we present a detailed spatial and temporal record of Ediacaran ocean chemistry for the Doushantuo Formation in the Nanhua Basin, South China. We find evidence for a metastable zone of euxinic (anoxic and sulfidic) waters impinging on the continental shelf and sandwiched within ferruginous [Fe(II)-enriched] deep waters. A stratified ocean with coeval oxic, sulfidic, and ferruginous zones, favored by overall low oceanic sulfate concentrations, was maintained dynamically throughout the Ediacaran Period. Our model reconciles seemingly conflicting geochemical redox conditions proposed previously for Ediacaran deep oceans and helps to explain the patchy temporal record of early metazoan fossils.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Li, Chao -- Love, Gordon D -- Lyons, Timothy W -- Fike, David A -- Sessions, Alex L -- Chu, Xuelei -- New York, N.Y. -- Science. 2010 Apr 2;328(5974):80-3. doi: 10.1126/science.1182369. Epub 2010 Feb 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, Riverside, CA 92521, USA. chaoli@ucr.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20150442" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
*Biological Evolution
;
Carbonates/analysis
;
China
;
Ferrous Compounds/analysis
;
*Fossils
;
Geologic Sediments/*chemistry
;
Hydrogen Sulfide
;
Iron
;
Oceans and Seas
;
Oxidation-Reduction
;
Oxygen/*analysis
;
Seawater/*chemistry
;
Sulfates/analysis
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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