[meteorite-list] Re: Dean's new NWA group

From: fcressy <fcressy_at_meteoritecentral.com>
Date: Thu Apr 22 09:52:19 2004
Message-ID: <000d01c24953$a8d99460$bc7c7243_at_g10fb>

Hello Rob, Bob, Dean and all,

I tend to be a "lumper" I guess when it comes to classifications. Makes it a
bit simpler for my mind to digest ;-)

Although the 41 black stones that Dean is selling were shipped together and
appear to be from the same find, I agree it is possible that they may not be
paired, so lacking any additional data, I have no problem with different
NWA numbers for each. However, if Dean can check with his Moroccan contacts
and see if they were collected in the same area and not high-graded from
different falls, I would tend to want to assign only a single NWA number
especially if all cut ones appear visually the same.

If the stones indeed are all from the same find, I don't want the fact that
there were at least 41 stones in it totaling 7.7 kilograms lost. Any find or
fall information that can be inferred from the NWA stones (ie TKW, number of
stones, etc) is important too. If individual NWA numbers are given, this
data could be lost or difficult to find again. I think that at the very
least, they need to be cross referenced to each other with a note stating
that "they were part of a shipment from Morocco of 41 similar sized and
similar looking black crusted meteorites suspected of being paired".

Incidently, did you check out the size distribution of the 41 stones? Except
for one stone (624 grams) all the rest fall betweem 100 and 400 grams. Where
are the expected small sizes below 100 grams? If they are indeed from the
same find, I suspect that Dean probably will be getting another package soon
with the "babies" ;-)
 If the "babies" do come, say 100 more or so, do they all get individual NWA
numbers?

I agree 100% with Rob's assessment below.

> It comes back to the same old dilemma: there are currently far
> more meteorites than there are resources to analyze them, but the
> only way to be reasonable sure of pairing common meteorites
> (absent physical pairing) is to thin section and probe every one.
> A problem with no imminent solution... --Rob


Regards,
Frank


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Received on Wed 21 Aug 2002 04:45:13 PM PDT