[meteorite-list] Ghubara Revisited

From: Alexander Seidel <ase_at_meteoritecentral.com>
Date: Thu Apr 22 09:37:34 2004
Message-ID: <3A395B91.E75716D_at_planet-interkom.de>

Bernd wrote:

> With the help of a 12x loupe, I took another look at my Ghubara slice
> and noticed about an equal number of chondrules in both "lithologies",
> whereas James' xenolithic component almost seems to be devoid of any
> chondrules; so now I am at my wit's end :-(
>
> Folks, grab your Ghubaras, look at them closely, take your Ghubara thin
> sections and examine them in plane and polarized light and report to the
> list your findings. I think this is a great occasion for this list to do
> invaluable scientific, observational work.

There is a big light-brown clast in my very flat 65 g Ghubara endcut
which shows abundant chondrules of different sizes up to 2.5 mm, tightly
packed together with low visible metal as compared to the adjacent
matrix field showing significantly more metal grains and also
well-developed chondrules from small (< 1 mm) up to almost 3 mm size,
also very abundant but not quite that tightly packed than in the clast.
The matrix of Ghubara is a little bit resembling that of the Barratta
meteorite (which was reclassified as L3.8), though Barratta (a truly
exciting meteorite!) is much more shock-darkened and shows a clearly
more diverse texture with more contrasts and a wider variety of light
inclusions in a dark matrix.

Unfortunately, Ghubara is prone to rust, so be careful folks with
potential buys of that material which has been offered surprisingly
cheap (..for that kind of a meteorite..) over the past few months.

Alex

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Received on Thu 14 Dec 2000 06:45:21 PM PST