Thorny wrote <<...If this is true, how can the hundreds of uncut,
unclassified rocks from northwest Africa be passed off as
meteorites? >>
Good question Thorny:
There are specific areas where, geologically, meteorites have accumulated
for tens (hundreds) of thousands of years. These areas are flat and arid,
and where erosion rather than deposition has occurred, and the soil chemistry is
not unfavorable to their preservation. Its not that they are that easy to
find, but the Berbers (native wandering tribes) cover much territory and they
have been taught how to recognize possible meteorites in their travels, so in
this way they are educated to know what to look for.
Take, for example, the Dar al Gani (DaG) plateau in Libya. Its very
flat, dry, and meteorites stand out as different from the native rocks.
You still don't just "go there" and expect to pick them up. It is
necessary to spend literally weeks and months searching, and covering much
territory. And you need to know what to spot. This takes a
practiced eye. The finds may be many miles or tens of miles apart.
Meteorites (meteorwrongs) brought to researchers here by the lay public
usually are not meteorites because the finders really don't know much about what
to look for in recognizing them.
If you go where the terrain is right, and the area is virtually unsearched,
given enough hours of searching and area covered, with an experienced eye, you
will find real meteorites.
I can't imagine how many hundreds(?) of (native) people are hunting all
over Morocco and Algeria right now. Its like a great "gold rush".
With their economy, its well worth their time to be on the lookout for possible
meteorites. Most people who deal in meteorites know their geology and
petrology pretty well and can do well in spotting at least, the more common
types of meteorites. But not all suspected meteorites turn out to be so;
they still need to be classified not only to determine to be accepted as
authentic but also, and JUST AS IMPORTANT, to know their chemistry and history
of formation. This can only be done using the electron microprobe and
petrologic microscope (and of course a trained geochemist with the
experience).
Hope this answers some of your questions.
Ron
R. N. Hartman
METEORITES and MEMBRANE SUSPENSION BOXES
[EMAIL PROTECTED]
www.meteorite1.com
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Mailing address:
The R. N. Hartman Collection
METEORITES
P.O. Box 94
Walnut, CA 91788-0094 (U.S.)
----- Original Message -----
From: thornysahuaro <[EMAIL PROTECTED]>
To: meteorite list <[EMAIL PROTECTED]>
Sent: Monday, August 12, 2002 8:07 PM
Subject: [meteorite-list] How do you know?
> I have been told that only one in one thousand rocks submitted to the
> experts at the universities and other meteorite identification labs, turns
> out to be an actual meteorite. If this is true, how can the hundreds of
> uncut, unclassified rocks from northwest Africa be passed off as
> meteorites? I'm not questioning that they all are, and I'm certainly not
> doubting any of the list members who are selling them. I just would like
> to know if there is some magical test. Is the Sahara, like the ice of
> Antarctica, the test itself? Does any rock that sits on the sand
> automaticly become a meteorite candidate because that is the only way it
> could have gotten there?
> I've got on my asbestos BVD's, so light the flamethrowers.
> Thorny
>
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