[meteorite-list] Terrestrial Impact Craters in Unconsolidated Sediments Questions?

From: littlejo_at_ctc.net <littlejo_at_meteoritecentral.com>
Date: Thu Apr 22 09:52:10 2004
Message-ID: <20020811004405.XIGH331.host4_at_[166.82.1.69]>

I was looking the lists of known **terrestrial**
impact craters. In the small to medium size craters,
I noted that I could not recognize any in which the
target material consisted of unconsolidated
sediments, e.g. either alluvium, quaternary
terraces, or coastal plain. The know craters that
are greater than 0.4 km in size all seem to be
excavated in bedrock.

Is there any example of an impact crater greater
than 0.5 km in size that has been formed in
unconsolidated sediments like those underlying
quaternary terraces, alluvial plain, deltaic, or coastal
plain? What would such an impact crater in
unconsolidated sand look like?

Has anyone published anything either about such an
impact crater or what type of feature an impact would
produce in unconsolidated sediment. For example,
it would be impossible for a crater the size of
Barringer Crater in Arizona formed unconsolidated
sediments to maintain the steep walls and deep
crater that Barringer crater has. Thus, it would be
impossible for a crater the size of Barringer crater
to have the same form in unconsolidated coastal
plain sediments that the Barringer crater exhibits in
solid rock. What would a coastal plain crater look
like if the depth of unconsolidated sediments
exceeded the depth of the crater?

(I am thinking of something way smaller than the
Cheasapeake Bay crater, which because of its size,
was blasted through the coastal plain sediments.

Just Curious?

Yours,

Keith Littleton
New Orleans, LA
Received on Sat 10 Aug 2002 08:44:05 PM PDT