Debut of chromium signatures clocks great oxidation event
Banded ironstone core samples from the Pilbara have aided in dating the first appearance of atmospheric oxygen at 2.48 billion years ago.
Nov 25, 2011
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Nov 25, 2011
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Oxygen-free early oceans likely delayed rise of life on planet
Geologists at the University of California, Riverside have found chemical evidence in 2.6-billion-year-old rocks that indicates that Earth's ancient oceans were oxygen-free and, surprisingly, contained abundant hydrogen sulfide ...
Jan 10, 2011
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Geologists revisit the Great Oxygenation Event
In "The Sign of the Four" Sherlock Holmes tells Watson he has written a monograph on 140 forms of cigar-, cigarette-, and pipe-tobacco, "with colored plates illustrating the difference in the ash." He finds ...
Aug 19, 2010
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