O2 formed in earth`s oceans 100m-yr before GOE

Last Updated: Thursday, November 5, 2009 - 09:22

Washington: Oxygen production began in
earth`s oceans at least 100 million years before the life
saving gas accumulated in its atmosphere, a new research
claimed.

A team led by geoscientists at the University of
California, Riverside, said, "Oxygen production began in
earth`s oceans at least 100 million years before the `Great
Oxidation Event`(GOE) and demonstrated that even very low
concentrations of oxygen can have profound effects on ocean
chemistry".

GOE was the event when earth transformed from an
oxygen-poor atmosphere to an oxygen-rich one paving the way
for complex life to develop on the planet. Scientists widely
accept that it happened around 2.4 billion years ago.

To arrive at their results, the researchers analysed
2.5 billion-year-old black shales from Western Australia.
Essentially representing fossilized pieces of the ancient
seafloor, the fine layers within the rocks allowed the them
to page through ocean chemistry`s evolving history, the
University of California, reported.

Specifically, the shales revealed that episodes of
hydrogen sulfide accumulation in the oxygen-free deep ocean
occurred nearly 100 million years before the GOE and up to 700
million years earlier than such conditions were predicted by
past models for the early ocean.

Bureau Report



First Published: Thursday, November 5, 2009 - 09:22

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