[meteorite-list] NWA & Saharan meteorites

From: Frank Cressy <fcressy_at_meteoritecentral.com>
Date: Thu Apr 22 09:42:02 2004
Message-ID: <001f01c08323$99c20fe0$7332ff3f_at_pavilion>

Hello all,
I found a couple of pennies in my pocket so I too felt obligated to add my
two cents concerning NWA meteorites :-)

First, I too would rather have a named specimen over a NWA XXX specimen all
things being equal. However all things are not equal. And we shouldn't
write off the common NWA meteorites (except maybe the weathered, fractured,
almost-dirt junk) as they have much to offer us. We just need to be
discriminating and pick carefully.

As an example I obtained a couple of large common L6 NWA (classified) slices
(300 to 500 g) that offer a wonderfull opportrunity to observe the interior
structure and texture on a larger scale that wouldn't be possible with a
micro specimen. And this was for the same cost as a "named" micro. As thin
sections offer a "micro" view of the meteorite universe, these large slices
offer a different view that we shouldn't ignore, but that many of us are
forced to ignore because of cost. In the past couple of years I have seen
affordable (to me) large slices of only one "named" meteorite, that being
Wagon Mound.

I have also obtained a few "named" individuals (which I enjoy immensely),
but again cost limited my largest purchase to something I can almost hide in
one hand:-( With the availabllity of the Saharan meteorites I was able to
obtain a great fusion crusted, thumbprinted (NWAXXX named) individual that
Tim (the tool man) Taylor would be proud of:-)

Some of the rarer NWA pieces offer the same opportunity but on a smaller
scale. Try getting a part slice of a CO3 for $10 to $20/gram prior to the
large Saharan finds. I obtained a thin 3 x 2cm Saharan CO3 slice that shows
some textural differences that you won't see on a micro sample. I preferr it
greatly over my small Kainsaz micro. (I may have to email MM now that the
prices seem to be falling :-)

On a philosophical meander, it is sort of like going to study the forest. We
shouldn't just concentrate on the bark of the tree. We also need to look at
the leaves, branches and roots. The trouble with "named" meteorites is that
monetary constraints limit many of our views to only a portion of a tree.
The low cost of the common NWA meteorites allows us a larger view. We may
even get to see the entire tree, and perhaps, even get a glimpse, however
fleeting, of the forest.

And even some of the NWA junk has a purpose. I'm giving a talk on meteorites
to my daughter's class next week and several small cut fragments of
unclassified NWA material are the perfect handout for the class.

Just some of my thoughts.
Regards,
Frank
Received on Sat 20 Jan 2001 03:57:27 PM PST