[meteorite-list] NWA 3118 CV3 Chondrule-Field Update

From: Adam Hupe <raremeteorites_at_meteoritecentral.com>
Date: Tue Feb 22 15:43:27 2005
Message-ID: <01b201c5191f$37148760$6401a8c0_at_c1720188a>

Dear List Members,

There was some question about the strange clasts in the NWA 3118 CV3s. They
looked like CO3 chondrule-fields to me so I had them studied. Oxygen
isotope studies were performed at Carnegie and Petrologic/Microprobe work
was performed at UW. Here are the most interesting results:

Northwest Africa 3118, additional data
 Morocco
 Purchased 2003 December
 CV3 chondrite
A small stone representing part of the main mass held by A. and G. Hup?
(Hup?) was found to contain a dark inclusion measuring approximately 9 cm by
2.5 cm by 1 cm. Microprobe examination of the inclusion by A. Irving and S.
Kuehner (UWS) shows it to consist of small chondrules and chondrule
fragments composed of very magnesian olivine (Fa1.1) with marginal Fe-rich
reaction zones (Fa36.9) against a porous matrix composed of felted blades of
relatively ferroan olivine (Fa40.9-45.9) with accessory troilite and
pentlandite. This clast has the attributes of Type A/B dark inclusions
described by Brearley and Jones (1998, p. 3-227), and the textures suggest
that it may have formed by partial sublimation of original chondrules and
re-condensation. Oxygen isotope analysis by D. Rumble (CIW) of acid-washed
whole inclusion material by laser fluorination gave replicate values of ?17O
= +0.08, -0.18; ?18O = 5.14, 4.99; ?17O = -2.63, -2.81 per mil,
respectively, which plot on the best fit line for whole rock CV chondrites.

Here is a specimen that clearly demonstrates what the above report
describes:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418

I hope you found the above data as interesting as I did.

Kind Regards,

------------------------------------
Adam Hupe
The Hupe Collection
Team LunarRock
IMCA 2185
raremeteorites_at_comcast.net
Received on Tue 22 Feb 2005 03:43:49 PM PST