[meteorite-list] Dhofar 908 3-lithology photo

From: Norbert Classen <trifid_at_meteoritecentral.com>
Date: Mon, 4 Jun 2007 23:46:12 +0200
Message-ID: <003701c7a6f1$c776cf90$2002a8c0_at_lunatic>

Hi David, and All,

Stephan's photo shows another section through the 81 main mass of Dhofar
908, and it's actually one of the very few pieces that has all three major
lithologies. The three lithologies are spatially separated in the main mass,
with one end consisting mostly of a clast poor, brownish IMB similar to
Dhofar 305, while the middle of the stone mainly consists of a clast rich
IMB with large anorthositic and other lithic fragments as can be seen in the
lower part of my favourite slice, and which is similar to Dhofar 306, and
other pairings:

http://www.meteoris.de/img/ncc-lun/Dho908-2.54g.JPG

The upper, dark part seems to be a more mature regolith breccia, something
that is consistent with cosmogenic nuclides studies by Kuni Nishiizumi.
Speaking of that, this is a very old meteorite, and only one lunar meteorite
has a even higher terrestrial age, Dhofar 025 & pairings. According to Kuni
Nishiizumi's studies, Dhofar 908 has a terrestrial age of approximately
350,000 years, placing its fall into lower palaeolithic times, and the reign
of Homo erectus rather than Homo sapiens.

Back to Stephan's slice: it has another special feature to the lower right -
that large round redish clast seems to be a troctolite, and it's most
similar to large clasts in Dhofar 310. I won't call this a fourth lithology
because it's "just" a clast, but it's rather fascinating, though. Nice!

All the best,
Norbert


-----Urspr?ngliche Nachricht-----


Hello All,

This List is amazing at times. I asked if there was a photo from the
"Rosetta Stone" of Dhofar 908 showing the 3 lithologies, and Stephan
Kambach very kindly sent me one. It's a beauty too! I have it displayed
on my webpage at the bottom along with his explanation of the various
components -- be sure to click the photo for a greatly magnified view.
It's a must see.

http://meteoritestudies.com/protected_DHOF908.HTM

Thanks Stephan (and Norbert for finding it).

David
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Received on Mon 04 Jun 2007 05:46:12 PM PDT