[meteorite-list] Scientists Excited About Potential Impact CraterSite in Missouri

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Mon May 23 00:41:35 2005
Message-ID: <42915ED9.16500D4E_at_bhil.com>

Hi,

    The Weaubleau crater is part of a suspected crater chain.
    "Eight circular depressions (3-17 km wide) distributed along a 700 km line
across Kansas, Missouri, and Illinois may comprise part of a crater chain (M.R.
Rampino and T. Volk (1996) Geophys. Res. Lett. 23, p. 49.) Two of the eight
structures (Decaturville and Crooked Creek in Missouri) are known from field
studies to be impact craters ~300 Myr old." And it's a very straight line as
can be seen on the map at:
<http://www.boulder.swri.edu/~bottke/crater_chain/chain.html>
    The eight locations are: Hicks, IL; Avon, MO; Furnace Creek, MO;
Crooked Creek, MO; Hazel Green, MO; Decaturville, MO; Weaubleau, MO; Rose,
KS.
    To me, Crooked Creek is the clearest and most obvious impact crater -- its
central rebound peak is indicated, which suggests that it may have had more
rings than it does now, 6 kilometers being a smallish crater to have produced a
central peak, I would think.
    I had a nice aerial of it I could have posted, but now my hard drive just
throws up its hands and tries to look innocent when I search for it. But here's
a different photo and a map:
<http://www.unb.ca/passc/ImpactDatabase/images/crooked-creek.htm>
    The 19 kilometer Weaubleau structure is virtually hidden from ground view,
but it shows up in radar from orbit very nicely. Here's a radar map of
Weaubleau at:
<http://geosciences.smsu.edu/faculty/Evans/impacts.htm>
    Eight hits in a row. Shades of Shoemaker-Levy!
    So, we in the Mid-West have more craters than you guys in Arizona, but your
one is a lot prettier than our eight...

Sterling K. Webb
--------------------------------------
Ron Baalke wrote:

> http://springfield.news-leader.com/news/today/20050522-Scientistsexcit.html
>
> Scientists excited about potential site of meteorite
> By Mike Penprase
> News-Leader.com
> May 22, 2005
>
> The crash millions of years ago of what could have been a 900-foot-wide
> meteorite in St. Clair County could provide lessons for today if a small
> meteorite evading current detection methods hits Earth, an Austrian
> scientist told colleagues at a meeting Saturday at SMS.
>
> "It's not a question if it will happen again, it's a question of when it
> happens again," University of Vienna researcher Christian Koeberl said
> after a group of researchers who study meteorite impacts described
> research from South America and Africa to near the Arctic Ocean.
>
> Koeberl, who talked about a multinational research effort at the
> Bosumtwi Impact Crater in Ghana, said he's looking forward to possibly
> working with Southwest Missouri State University geology professor Kevin
> Evans and other university researchers on what's now called the
> Weaubleau-Osceola Structure.
>
> Koeberl doesn't predict when meteors might become meteorites and strike
> the Earth; he describes what happens when they hit, he said Saturday
> before members of the Society for Sedimentary Geology. They were
> attending a research conference at SMS and will today move from their
> lecture room to climbing around shattered rocks in an area along
> Missouri 13 between Osceola and Weaubleau.
>
> If a meteorite created the structure, it hit some 300 million years ago
> when mid-Missouri was part of an ancient Jurassic Age sea. The strike
> obliterated plant-like crinoids, Koeberl said.
>
> A similar event today would be cataclysmic, he said.
>
> "Today, if something like this would happen, you'd have a kill zone of
> 50 to 100 kilometers," he said, an area equivalent to 31 to 62 miles
> around the impact site.
>
> U.S. Geological Survey scientist Jean Self-Trail of Virginia said she's
> looking forward to today's field trip.
>
> "The evidence looks fairly compelling to me," said the scientist working
> on studying an impact site in Chesapeake Bay. The Missouri site is one
> of several some scientists say run in a line from Kansas to Indiana.
>
> Whether impact can be added to the Weaubleau-Osceola Structure or not
> depends on more intensive research, Evans said.
>
> But Evans is confident a theory will become accepted fact.
>
> "It's pretty well accepted, actually," he said. "We still have a lot
> more work to do. The impact community is pretty well behind us."
>
> But discussing how ??? or whether ??? meteorites created the growing number
> of craters found around the world can be intense.
>
> Austrian scientist Koeberl wants more evidence before declaring the
> Weaubleau-Osceola site about 60 miles north of Springfield a meteorite
> impact site.
>
> "At this point, there really is no confirming evidence," he said.
>
> Twisted layers of rocks and an impact-related stone called breccia are
> present, but Koeberl wants to see direct evidence a meteorite hit by
> detecting bits that survived an impact so violent it could have caused
> the inland sea to recede for a time, Koebel said.
>
> That's why Evans said he and others are working on a grant application
> to better fund research and have an acknowledged expert in his field
> like Koeberl participate.
>
> People like Evans are fascinated by the idea that a giant rock fell on
> the Earth, but he said researching meteorite impacts can affect
> non-scientists, too.
>
> The most obvious way is providing information on what might happen when
> a meteor flying through space becomes a meteorite when it strikes Earth.
>
> And there actually are benefits from such cataclysmic events, Evans said.
>
> Major oil and mineral deposits have been found near impact sites.
>
> The meteorites themselves didn't create oil, zinc, or gold, but they do
> create the conditions needed for those minerals to be deposited, he said.
>
Received on Mon 23 May 2005 12:40:58 AM PDT