[meteorite-list] Meteorites 'Cause Volcanic Eruptions'
From: Jerry <grf2_at_meteoritecentral.com>
Date: Wed, 10 Sep 2008 20:10:47 -0400
We've gota love this!!!!!!!!!!!!!
Where are those immense Deccan Volcanic flats that accounted for Extinction?
----- Original Message -----
From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Sent: Wednesday, September 10, 2008 1:46 PM
Subject: [meteorite-list] Meteorites 'Cause Volcanic Eruptions'
> Meteorites 'cause volcanic eruptions'
> In The New (United Kingdom)
> September 10, 2008
> Violent volcanic eruptions witnessed from the dawn of time to the
> present day could all have been prompted by meteorite strikes billions
> of years ago.
> Geologists are presenting new evidence that contradicts the belief the
> gas that causes volcanoes to erupt - 'light' helium - came to Earth via
> its gravitational pull.
> Volcanic eruptions occur when the gas, which arrived when the world was
> in a molten state and is trapped in the deep Earth, melts.
> But University of Manchester scientists say that the 'fingerprint' left
> by the 3He isotope does not match solar nebula but instead meteorites.
> "We have shown that the neon gas fingerprint expected for the captured
> solar nebula model is not matched," Professor Chris Ballentine said.
> "Instead we have found a meteorite signature, which suggests the massive
> early atmosphere is not trapped by gravitational attraction as
> originally thought but a result of meteorites spewing out gas on impact."
> Prof Ballentine and his team also identified a second signature,
> obtained via studying CO2 gas from the Colorado Plateau, which is
> identical to seawater.
> "The only explanation for this is that seawater trapped in ocean crust
> is being driven back down into the deep Earth in a tectonic process
> called subduction," he explained.
> Previous thinking had stated that water at these depths would be
> impossible due to it melting during the subduction process.
> "This process has the potential to fundamentally change how scientists
> think Earth has behaved over time. Even a little bit of water added to
> rock in the deep earth makes it more plastic and allows movement of
> tectonic plates sitting on top to be quicker," Prof Ballentine added.
> "The source and fate of atmospheres and water on planets is central to
> understanding the origin of life and the conditions that lead to our own
> planet looking as it does today. Our work provides evidence that changes
> our big picture understanding of how planetary systems acquire their
> volatile elements.
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Received on Wed 10 Sep 2008 08:10:47 PM PDT