Monday, May 18, 2009

'Volcanic shutdown' responsible for oxygen boost?

An increasing pile of evidence suggests volcanic activity on earth mysteriously stopped for about 250 million years (between 2.45 and 2.2 billion years ago). Scientists don't know why (it could, perhaps, be due to a pause in tectonic activity), but they believe the volcanic slowdown may responsible for the spike in atmospheric oxygen around 2.4 billion years ago.

What's the connection? "Oxygen produced by marine microorganisms was consumed in reactions with iron in the ocean. With no fresh volcanic material to replenish the iron, oxygen would have been free to build up in the atmosphere."

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.