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Re: "Meteor theory gets rocky ride from dinosaur expert"
On Sun, 29 May 2005 04:50:29 -0700 (PDT) Tim Donovan <email@example.com>
> > So it is possible
> > that some reworking of
> > a *portion* of the largest spherules had occurred.
> Does the evidence indicate this?
As Jim C. has already pointed out, "yes".
Actually, I was thinking of the more proximal spherule deposits that are
found in outcrop in Haiti. A few sites are composed of nothing but
spherules! (I would *love* to visit these sites). Some of the Haitian
deposits show strong crossbedding. I assume that the currents
responsible for the crossbedding were caused by the later "backslosh"
rather than from the primary tsunami wave (the primary wave probably had
a strong erosive effect on the sea floor).
The phenomenon of reworked spherules is of course dependent on the
outcrop's paleodistance from the crater. Each locality will show
different stratigraphy (even with some layers in "reverse order" compared
to other localities).
BTW: Are there any Windoze programs (preferably freeware or shareware)
that compute great circle distances between two points on the earth? I'd
even be happy to get a GWBASIC program that does this. TIA.