[meteorite-list] Moss Meteorite

From: David Weir <dgweir_at_meteoritecentral.com>
Date: Sat Aug 26 18:37:02 2006
Message-ID: <44F0CCEC.7040306_at_earthlink.net>

Hello Bernd,

I have read different stats for the kakangariites than you have stated.
My sources are Classification of Meteorites, Krot, Keil, Goodrich,
Scott, and Weisberg (from Treatise on Geochemistry 1, 2005); The K
chondrite grouplet, Weisberg, Prinz, Clayton, Mayeda, Grady Franchi,
Pillinger, and Kallemeyn (GCA 1996); and The Textures and Abundances of
Chondrules in the Kakangari Chondrite, Genge and Grady (LPSC 24 #1670).
Newer information has discredited Lea Co 002 from being a member of this
grouplet, so now there are only Kakangari and LEW 87232 - perhaps that
has skewed some numbers you referenced. Here are my stats for features
of these two members which can be measured outside of the lab for the
most part:

chondrule size peak is 0.25-0.5 mm
70-77 vol% matrix content
metal content similar to H chondrites (6-9 vol%)
sulfides 6-10 vol%
CAIs less than 0.1 vol% (0.05 - 0.4 mm)
D17O (when conducted) should be -1.6

The high metal (as indicated by the numerous rust spots) is unlike that
of a CK I think. I haven't investigated its similarity to COs since that
is the ongoing hypothesis of its class and I can live with that.
Obviously it will take a lab to know what Moss is, but a kakangariite is
not out of the running in my opinion.

David

bernd.pauli_at_paulinet.de wrote:
...
> There is not very much I can say about the Moss meteorite as I don't
> know it in person - I've only seen some pictures so far. It looks
> very much like a CO or a CK chondrite. I don't believe it is a
> Kakangari-like meteorite (see David Weir's previous post to the List)
> but if it was one, that would be a blast, of course! If it is a KAK,
> it should have some of these characteristics:
>
> - its oxidation state resembles that of enstatite chondrites - there
> is a high abundance of pyroxene (more than olivine) - its oxygen
> isotopes are comparable to those of CH or CR chondrites - a high
> metal content similar to that of H chondrites.
>
> If Jeff Kuyken's observation (see his website) about Moss chondrule
> size is correct, 0.25-0.30 mm, this would favor a CO classification.
> CK chondrites tend to have a chondrule size of 0.8 mm. KAK meteorites
> have a chondrule size of 0.69 mm (according to Hutchison). Jeff's
> estimate of the volume of chondrules (about 50%) would also favor a
> CO classification (40 vol %) instead of 15 vol % for CK's or 19% for
> KAK. Whatever it is, it is a beautiful, pristine new fall ...
>
> Cheers,
>
> Bernd
>
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Received on Sat 26 Aug 2006 06:36:28 PM PDT