[meteorite-list] Smacked by gob

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Sat, 22 Nov 2008 11:10:29 -0500
Message-ID: <5mbgi452911vk9gi82hueeaa6oqgvirj77_at_4ax.com>

http://www.theage.com.au/national/googling-geologist-identifies-possible-meteorite-crater-out-the-back-of-bourke-20081122-6eix.html

Googling geologist identifies possible meteorite crater out the back of Bourke

    * Richard Macey
    * November 23, 2008

A RETIRED geologist searching on Google Earth for a place to mine opals may have
discovered something much bigger: a meteorite crater in outback NSW.

Mike Fry, of Maryborough in central Victoria, was using the Google site last
month to survey terrain when he saw an unusual structure in the red dust.

"The circular nature of this thing struck me," Mr Fry said. "It was so
distinctive, I was gobsmacked."

Mr Fry, who earned a degree in geology from the University of New Mexico before
coming to Australia 44 years ago to mine opals and gold, drove for 11 hours to
the site to take a look. The site is about 10 kilometres north-east of White
Cliffs, a town halfway between Broken Hill and Bourke in far north-western NSW.

"I have walked around it," he said, estimating his "crater" was at least two
kilometres across. "There is a steep slope on the eastern side, which rises 30
to 50 metres above the floor."

The western rim was severely eroded. However, the eastern side had been
preserved under a layer of sedimentary material called silcrete, formed from
dissolved silica, that he believes was laid down more than 2 million years ago.

"Silcrete is as hard as concrete," Mr Fry said. "The crater had to exist before
the silcrete was laid down."

Several scientists who looked at the images agreed that while circular shapes
could be produced by many geological forces, including volcanic activity, the
feature deserved further investigation.

"It does look the right sort of shape," said Andy Tomkins, of Monash University.
"It is the pattern you would expect to see. It looks interesting."

Peter Haines, a senior geologist with the Geological Survey of Western
Australia, said he would remain "a bit sceptical" until the site was tested.

However, he added, "just looking at it, it's something that should be followed
up".

Dr Tomkins and Dr Haines said finding microscopic evidence of rock that had
suffered a severe shock would indicate an impact crater.

If Mr Fry has found an impact crater, it would be the second such discovery
using Google Earth.

Last year Dr Arthur Hickman, a geologist with the Geological Survey of WA, found
a crater, about 260 metres wide and up to 30 metres deep, in the Hamersley
Ranges in WA's Pilbara region.

Dr Haines said it was certainly possible a two-kilometre meteorite crater had
gone unnoticed. "It is not something that would necessarily attract the
attention of someone who was not already thinking about a crater." A crater,
agreed Dr Tomkins, "could easily be missed".
Received on Sat 22 Nov 2008 11:10:29 AM PST


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