[meteorite-list] Bediasites agree with Steve's unproven tektite theory

From: brian burrer <brimane_at_meteoritecentral.com>
Date: Fri, 24 Feb 2012 15:49:31 -0600
Message-ID: <CA+VWDOK-gCDrL=VX++DkgAXQHvwv+RTT7QhisBufoo0Du84F2g_at_mail.gmail.com>

Hi list,

Bediasites are well known for, among other things, these two traits:

1.Most Bediasites show ample evidence of abrasive transport and minor
to severe smoothing of the surface.

2.Bediasites are found in/on the basal portion of the Manning unit of
the Jackson formation in Texas. They are almost never encountered
"off formation". The age of volcanic ash later/higher in the Manning
is about one million years after Bediasite formation so the tektites
were placed there rather soon after the event.

The age of deposition of the Bediasites in the Manning would be about
thirty five million years ago. Despite the passing of an immense
amount of time etching has failed to significantly alter the surfaces
of the tektites. U-grooves, V-grooves and navels all exist on stones
with different amounts of ancient abrasion only slightly muting some
and almost obliterating others. If they were in an environment
conducive to etching after burial Bediasites should all be similar to
the Besednice hedgehog Moldavites. The evidence suggests that little
etching has occurred on most Bediasites after transport.

These things taken together suggest that surface sculpture on
Bediasites was a pre-existing condtion and was not developed by later
etching.

There is one small problem with this; the tektites did get some amount
of time (less than one million years) to etch prior to their addition
to the basal Manning sediments. While it is possible they were
heavily etched in their earliest years and then abrasively
transported, it is certain they did not etch significantly once
buried.



Happy hunting,
Brian
Received on Fri 24 Feb 2012 04:49:31 PM PST