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Tektite question

In regard to the tektite origin question I would offer the follow for the
list's thoughts.

An australite type button was recovered from a mid-Indian Ocean core with a
micrometeorite impact pit. Several problems come to mind. 

First, the mechanics to make any tektite in the normal splashform sizes has
not been demonstrated, however the experimental formation of australite
copies in the laboratory has been done. The speed to do ablation is well
defined. The old saying what goes up must come down presents a problem for
confined distribution when the up portion of a body's flight is riding the
edge of escape velocity.

Micrometeorite impacts normally occur above the atmosphere. Even allowing
for the existence of a rarefied bubble resulting from the asteroid or comet
impact there is a statistical problem. What is the likelihood we would find
one micrometeorite pitted tektite that formed during the brief interval
when there was no atmosphere or the object was high enough to be impacted.
Also, how well would a micrometeorite do in the high velocity steam that
existed at the time the million of tons of tektite material was moving away
from the impact site. Could they successfully pierce or even survive such
an impact plume to impact a tektite.

The non-ablated side which was pitted was solid not plastic at the time of
impact. The glass is shattered into concentric ring fractures not splashed
out. Cut australites and I have personally thin sectioned two in the last
week always look the same, clearly they are a remelted object. They would
appear to form in a two step process.

The middle of the Indian Ocean is very far out of line with Australia for
the linear distribution theory.

Serious questions from the 60's as to the age of Australites remain
unanswered. Some are found in radio-carbon datable soils by archaeological
methods and have by the admission of those recovering them not been
reworked to locations other than where they fell. The radio-carbon dates
and the soil geology evidence itself speaks to a date under 20,000 years.

I would be perfectly happy to remove the Australites from the asian
strewnfield and make them a separate event, even despite the compositional
arguments some present to include them. I have serious questions about
tektite formation and as some of you know I have plenty of them to look at.
I think rather than accept the easy answer (or way out of the problem) the
basic questions of mechanics and glass manufacture need to be resolved. I
hope I don't get murdered for this posting. But, I would certainly accept
ideas from others. 







Jim Tobin
The Meteorite Exchange
www.meteorite.com
P.O.7000-455, Redondo Beach, CA 90277 USA