[meteorite-list] Google unEarths rare meteorite crater

From: Robert Verish <bolidechaser_at_meteoritecentral.com>
Date: Tue, 25 Mar 2008 22:32:38 -0700 (PDT)
Message-ID: <406324.21062.qm_at_web51711.mail.re2.yahoo.com>

<http://www.smh.com.au/articles/2008/03/25/1206207065556.html>

<http://www.smh.com.au/ffximage/2008/03/25/A_Hickman_in_Pilbara_wideweb__470x277,0.jpg>

Sudden impact: Google unearths rare meteorite crater

The Sydney Morning Herald
Stephen Hutcheon
March 25, 2008 - 12:30PM

'Arthur Hickman's discovery on Google Earth of what is
almost certainly a rare meteorite impact crater in
remote Western Australia has earned him both bragging
and naming rights.

Measuring 260 metres wide and up to 30 metres deep,
the divot is thought to be between 10,000 and 100,000
years old and was stumbled upon in the rich, rust
coloured landscape of the Hamersley Ranges in
Western Australia's Pilbara region.

If confirmed, the Hickman Crater will become just the
30th officially-verified meteorite impact crater in
Australia and the first such discovery since 2005.

According to the Earth Impact Database, a resource
maintained by the Geological Survey of Canada and
University of New Brunswick, only 173 such impact
craters have been discovered in the world.

The find will likely deliver a lifetime of peer group
kudos to Dr Hickman, a government geologist with the
Geological Survey of Western Australia.

"I wasn't looking for it," Dr Hickman recalled in a
telephone interview. "I was high up in Google Earth
[the free program that enables users to scour the
Earth using stitched together aerial and satellite
images] when I spotted this little circular structure
which
struck me as odd."

Dr Hickman, who heads his organisation's Pilbara
Craton Mapping Project, says he made the discovery
last July while he was looking for possible sites of
channel iron deposits - highly sought after alluvial
deposits from which the ore can be extracted very
cheaply.

Although the crater is situated about 1000 kilometres
north-east of Perth and more than 300 kilometres
south-east of Port Headland, it is only 35 kilometres
north of the mining town of Newman in an area that
has been previously surveyed.

Dr Hickman referred his find to Dr Andrew Glikson, an
impact crater expert who is a visiting fellow at the
Australian National University's
 
Research School of Earth Sciences.

Dr Glikson, who has been studying impact craters since
1968, visited the site in August and corroborated Dr
Hickman's hypothesis.

"It's a little beauty," he said in a telephone
interview. "It's an absolute gem in terms of youth and
preservation."

He said the only other explanation for the formation -
which is about the same size as the Melbourne Cricket
Ground - is a volcanic eruption.

But after finding the surrounding area "chockers" with
rock fragmentation consistent with a high velocity
impact, he has ruled this out.

"No other process could have created this type of
crater," said Dr Glikson, who estimates the meteorite
was between 10 to 15 metres in diameter when it
slammed into the Earth.

The two geologists - together with a third scientist -
have written and submitted a paper on the discovery to
the Australian Journal of Earth Sciences, where it
will be subjected to peer review.

The next step in the process of formal identification
involves returning to the site and trying to find
shards of meteorite that have been left behind, or
examples of terrestrial rocks that have been fused
 
together with extraterrestrial matter as a result of
the violent impact.

Dr Hickman, who hopes to visit the site for the first
time in May, says the site is about half a day's drive
north from the town of Newman following the
privately-owned rail line to Port Headland, which is
famous for its mile-long trains.

He said it was Dr Glikson's decision to name his find
the Hickman Crater. "I'm not that conceited," he said
modestly.

Dr Glikson, who also has another crater in Western
Australia named after him, says he couldn't explain
why the crater hadn't been found before.

"This one stands out like a sore thumb on Google
Earth," he said.

The crater site can be seen on Google Maps
(see link to map, below)
and on Google Earth (requires download).

<http://maps.google.com/maps?t=k&hl=en&ie=UTF8&ll=-23.037521,119.682956&spn=0.013882,0.020084&z=16&source=embed>

<http://www.smh.com.au/photogallery/2008/03/25/1206207068311.html>
Received on Wed 26 Mar 2008 01:32:38 AM PDT