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Meteor May Not Have Destroyed Dinosaurs Afterall?

A few comments about the K-T impact event from the peanut gallery--

* If the K-T event source crater is Cicxulub, why is the iridium anomaly
and ejecta with shocked quartz absent in the gorceixite-goyazite impact
spherules from the same crater?
 
* Impact ejecta: Tektites are formed under reducing conditions.  Impactites
are formed under highly oxidizing conditions--since many consider tektites
to be impactites, how can two extremely different origin environments be
combined in one event--instantaneously?

* Since there was no extinction caused by the supposed source crater for
the Australasian tektites (Note: the source crater hasn't been found yet or
may not even exist), it seems very unlikely that the K-T Chicxulub crater
could have caused mass extinction. Plus Chicxulub appears to be smaller than
the Australasian event.  Maybe we don't understand impact dynamics? Maybe we
don't understand what tektites are?  So what causes mass extinctions? 

For an excellent, "radical" look at this topic see: Edward Chao's
"Comparison of the Cretaceous-Tertiary Boundary Events and the 0.77 Ma
Australasian Tektite Event: Relevance to Mass Extinction," USGS Bulletin
2050. For sale by USGS Map Distribution Office, Box 25286, Bldg. 810,
Federal Center, Denver, CO 80225.


LOUIS VARRICCHIO
Environmental Information Specialist/Research Associate
 Upper Midwest Aerospace Consortium
 Odegard School of Aerospace Sciences
 University of North Dakota
 Grand Forks, N.D. 58202-9007
   Phone: 701-777-2482
   Fax: 701-777-2940
   E-mail: varricch@umac.org (in N.D.)
              morbius@together.net (in Vt.)

"Climate is what you expect, weather is what you get."--Robert Heinlein 

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