View the online abstract in Earth and Planetary Science Letters, Vol. 220, Issues: 1-2, March 2004, pp.41-55.

Abstract

The presence of relatively abundant bedded sulfate deposits before 3.2 Ga and after 1.8 Ga, the peak in iron formation abundance between 3.2 Ga and 1.8 Ga, and the aqueous geochemistry of sulfur and iron together suggest that the redox state, and the abundances of sulfur and iron in the hydrosphere varied widely during the Archean and Proterozoic. We propose a layered hydrosphere prior to 3.2 Ga in which sulfate produced by atmospheric photolytic reactions was enriched in an upper layer, whereas the underlying layer was reduced and sulfur-poor. Between 3.2 Ga and 2.4 Ga, sulfate reduction removed sulfate from the upper layer, producing broadly uniform, reduced, sulfur-poor and iron-rich oceans. As a result of increasing atmospheric oxygenation around 2.4 Ga, the flux of sulfate into the hydrosphere by oxidative weathering was greatly enhanced, producing layered oceans, with sulfate-enriched, iron-poor surface waters and reduced, sulfur-poor and iron-rich bottom waters. The rate at which this process proceeded varied between basins depending on the size and local environment of the basin. By 1.8 Ga, the hydrosphere was, relatively sulfate-rich and iron-poor throughout. Variations in sulfur and iron abundances suggest that the redox state of the oceans was buffered by iron before 2.4 Ga and by sulfur after 1.8 Ga.
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Product Type/Sub Type

nonGeographicDataset

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Creative Commons Attribution 4.0 International Licence

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Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2004-01-01T00:00:00

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

GA Catalogue Number

49026 Product http://www.ga.gov.au/metadata-gateway/metadata/record/49026/

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External Publication
Scientific Journal Paper
Earth Sciences

Resource Language

English

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utf8

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unclassified

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Unknown

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onLine

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distributor
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
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a05f7892-b999-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

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pointOfContact
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address