POSSIBLY WHY NO TEKTITES FROM P/T IMPAST

["Ray Stanford" <dinotracker@earthlink.net>]

Emma C. Rainforth said:

"Problems with a volcanic-only hypothesis: would volcanism have caused
Ni-enrichment? Can they explain the metamorphosed grains in this
layer? (And what about these grains anyway......are they actually
shock-metamorphosed, impact-origin types, or
volcanic-metamorphosed....and are there any tektites anywhere? I
suppose if it WAS an oceanic impact, the impact site has long been
subducted, and possibly the tektites may have not gotten as far as
falling-out on land, and also been subducted.....if Kaiho et al are
lucky...:-)"

    As to any tektites formed during a Permian/Triassic impact, while you
might be right about why none have been found, it seems reasonable that
tektites of such great age would have long ago disintegrated into smectitic
clay.  Perhaps one should look for such a layer of appropriate age.  In it,
tiny remnants of tektite glass might occasionally be found, but it seems
more likely -- in view of the large amounts of terrestrial erosion seen even
in tektites of the relatively young Australasian strewn field (which is only
about 700,000 years of age) that all glass might have broken down.

    If anyone needs references to studies clearly indicating breakdown of
tektite glass into smectitic clay, I will be happy to provide some, off
list.

Ray Stanford

"You know my method.  It is founded upon the observance of trifles." --
Sherlock Holmes in The Boscombe Valley Mystery