[meteorite-list] Manchester Scientist Finds Gas Meteor

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Jan 11 14:11:36 2005
Message-ID: <200501111911.LAA08533_at_zagami.jpl.nasa.gov>

http://www.manchesteronline.co.uk/business/scienceandinnovation/s/142/142345_chris_finds_gas_meteor.html

Chris finds gas meteor
Seb Ramsay
Manchester Online (United Kingdom)
January 10, 2005

A MANCHESTER scientist has led a team to a major breakthrough in the
search for the origin of gases deep within our planet.

After studying samples from volcanoes in the US, Dr Chris Ballentine and
his researchers have concluded that meteorite bombardment, after the
Moon was first formed, was the only way gases could have arrived so deep
within the Earth.

The new thinking marks a fundamental shift in long-held beliefs as to
how the dissolved gases ended up deep in the earth.

And they say the research, funded by the Natural Environment Research
Council, has profound implications for our understanding of Earth's
early history.

Manchester University's Dr Ballentine said: "Before the moon formed, the
Earth had a massive atmosphere. Scientists have argued for decades lava
lakes underneath this atmosphere contained dissolved gases, in the same
way that carbon dioxide gas is pressurised into fizzy drinks.

Dissolved

They believed currents in the magma oceans would take this dissolved gas
deep into the Earth where the molten rock would eventually freeze,
trapping the gases.

"But we know that a planet the size of Mars smashed into the Earth to
form the moon. This devastating impact would have destroyed the early
atmosphere and released any trapped gas, even from deep within the Earth.

"So we asked the question, `why do volcanoes still spew out gases from
so deep?'"

The team sampled volcanic gases in New Mexico. Uniquely, volcanic gases
here contain very little air contamination and this allowed the team to
measure rare forms of gases like neon for the first time. These samples
were used to produce exact `fingerprints' of the volcanic gas.

The team found that these fingerprints were identical to gases found
trapped in meteorites and not from an early atmosphere.

And they concluded that the only way these gases could have been added
to the deep Earth is by continued meteorite bombardment after the moon
was formed.

According to Dr Ballentine, tectonic activity on a huge scale must have
dragged the gases trapped in the meteorites from the surface downwards.
Received on Tue 11 Jan 2005 02:11:27 PM PST