Tracking Euxinia in the Ancient Ocean: A Multiproxy Perspective and Proterozoic Case Study
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- Timothy W. Lyons
- Department of Earth Sciences, University of California, Riverside, California 92521;
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- Ariel D. Anbar
- School of Earth & Space Exploration and Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287
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- Silke Severmann
- Department of Earth Sciences, University of California, Riverside, California 92521;
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- Clint Scott
- Department of Earth Sciences, University of California, Riverside, California 92521;
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- Benjamin C. Gill
- Department of Earth Sciences, University of California, Riverside, California 92521;
抄録
<jats:p> The evolution and extinction of life are tied intimately to the oxygen state of the ocean, and particularly to the presence of anoxic and H<jats:sub>2</jats:sub>S-containing (euxinic) water on a global scale. Anoxia and euxinia were more common in the past, relative to today's <0.5% euxinic seafloor. We are able to constrain the distributions of these conditions through a combination of indirect numerical modeling methods and more direct geochemical proxies, with particular emphasis on Fe-S-Mo analysis of fine-grained siliciclastic rocks for the latter. Establishing the spatiotemporal pattern of oceanic redox is more difficult with very old rocks because of the limited availability of well-dated, well-preserved materials that span shallow and deep environments across time lines. Despite these difficulties, the multiple approaches synthesized in our case study point to global oxygen-deficiency in the deep ocean and perhaps euxinia during most, if not all, of the Proterozoic and likely extending into the early Paleozoic. </jats:p>
収録刊行物
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- Annual Review of Earth and Planetary Sciences
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Annual Review of Earth and Planetary Sciences 37 (1), 507-534, 2009-05-01
Annual Reviews