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Article Abstract:
Recent data obtained by geologists on sulphur-isotope measurements in sedimentary rocks contradict the theory that Earth's atmosphere was oxygen-free until 2.4 billion years ago. Geologists have identified oxidized sedimentary rocks formed at a time when the atmosphere was thought to have been oxygen-free which they claim would have arisen in special ways, such as at localized 'oxygen oases' where photosynthesizing organisms enriched waters with oxygen.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2006
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A crystallizing dense magma ocean at the base of the Earth's mantle
Article Abstract:
A stable layer of dense melt formed at the base of the Earth's mantle probably underwent slow fractional crystallization. This layer could have held a variety of incompatible species for an initial basal magma ocean thickness of about 1,000 km.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2007
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Comment about this article or add new information about this topic:
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