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Re: craters and the k/t (Norm King)



Sherry wrote:

 > As I understand it, Chixalub is a bit too old for the K-T.

This is in dispute.  One researcher claims to have found such evidence.
This is, in part, why a psecial investigative team is out there checking
it out.

 > Didn't they find undisturbed sediment from the later Maastrican
 > (sp?) *inside* the thing? If it was volcanic or extraterrestrial,
 > anything from that age should have been *blown out*.

This has be claimed, but not yet confirmed.

Previously in this mailing list somebody stated that block slumping
from the rim can carry apparently undisturbed sediments well into the
interior of a crater after formation.

Careful lateral stratigraphic controls would be necessary to distinguish
such a case from other possiblities.

 > Well, I think if you take into consideration volcanic activity and the
 > fossil record, the impact theory is pretty weak. As far as the fossil
 > record goes, we find a history of decreasing diversity and numbers
 > approching the K-T. We also never have found an increase of fossils after
 > the K-T that would suggest a sudden massive death event.

Unfortunately, such an increase in fossils does not necessarily follow
a mass death event.  So the absene is incoonclusive.

Note, I do favor a multi-causal model, and I, too, doubt that the effects
of even a major impact would be as long-lasting as many have claimed.

 > Also, why would the effects of the impacts effect some animals and
 > not others?

Different tolerances, different life styles, different habitats,
plus being in the right place at the right time (there will always
be local areas where the effects are less).

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.