[meteorite-list] Opal miner stumbles on mega meteorite crater - With Picture

From: Jason Utas <meteoritekid_at_meteoritecentral.com>
Date: Sun, 23 Nov 2008 01:34:19 -0800
Message-ID: <93aaac890811230134h6e88f437qdb86d85082d7f760_at_mail.gmail.com>

http://www.theage.com.au/news/technology/biztech/opal-miner-stumbles-on-mega-meteorite-crater/2008/11/22/1226770814042.html

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 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 11 hours to the site, about 10 kilometres north-east of White
Cliffs, to take a closer look.

"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, washed away over time by creeks, 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," said Mr Fry, of Maryborough, in
Victoria. "The crater had to exist before the silcrete was laid down."

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

Andy Tomkins, from Monash University in Melbourne, said: "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
thoroughly 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, who said there was no evidence of ancient volcanic activity
in the area, 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 Western Australia, found a crater, about
260 metres wide and up to 30 metres deep, in the Hamersley Ranges in
Western Australia's Pilbara region.

Dr Haines said it was possible that a two-kilometre crater had gone
unnoticed. "It is not something that would necessarily attract the
attention of someone who was not already thinking about a crater."

Source: The Sun-Herald
Received on Sun 23 Nov 2008 04:34:19 AM PST