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Saturday, 13 March 2010

Why isn't documenting meteorites stressed enough?

Why isn't documenting meteorites stressed enough?

Paul Heinrich
Sat Mar 13 21:33:45 EST 2010

Eric wrote:

"Meteorite fragments found on dry lake beds or
anywhere on "old ground", do in fact move. In
my opinion coordinate data is still valuable, but
not as valuable as say data from a fresh meteorite

As a geomorphologist, I would disagree. Such data
from either "old ground" or "prehistoric falls" might
be just as valuable as data from fresh falls. The
distribution data from prehistoric falls, if collected
and preserved might be useful in evaluating the type
and rate of the geomorphic processes that modify and
the age of the landforms on which they are found.
This is because a meteorite strewn field in many ways
is a chronostratigarphic equivalent of a volcanic ash
beds in terms of providing a "deposit" that is of the same
age / point in time everywhere that pieces of it are found.
The way that individual meteorites belonging to a single
strewn field are moved about could be used to infer how
the surface of a landform has been modified and at what
rate since the meteorite fall creating it occurred. If the
strewn field data was collected and was accessible, I
would suspect that geomorphologists would use that
data in a wide variety of novel ways that neither I or
nobody else on this list could at this time predict or image.

Of course, once the "taphonomic" processes determining
how meteorites are moved around after a fall and whether
or not they are preserved are understood, I suspect that a
person can "back engineer" the process to predict where
to look for "fossil meteorites" from past falls even if they
have been buried. I still think that there a number of
Chinese falls, where even though they occurred centuries
ago, a person has a significant chance of still being able
to find meteorites from them if their "taphonomy" could
be figured out and predictions made as to where exactly
to look.

Looking at some of the phrase diagrams that
archaeologists have made showing the relationship
between different physical characteristics of soils
and sediments and the long term survival of iron
artifacts, it is quite clear that iron objects, including
meteorites, under specific circumstances can survive
even in wet soils and sediments that they become
buried in for significantly long periods of time.
They might be bit too rusty for many collector's
tastes. Still, they still have scientific value even in
less than pristine condition.

Just Some Thoughts,

Paul H.

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