[meteorite-list] Stan's NWA 2965 EL6/7

From: David Weir <dgweir_at_meteoritecentral.com>
Date: Sat, 02 Dec 2006 14:28:29 -0500
Message-ID: <4571D3DD.9000904_at_earthlink.net>

Hello List,

After reading the AGU abstract posted by Greg, I certainly think the
investigators have made huge progress in arriving at a consensus on the
correct classification of this 1+ ton mass, previously described as an
igneous aubrite, a highly equilibrated EL6/7, and an En-metachondrite,
and, after analyzing the NWA 2828 stone, was considered to represent
multiple meteorite falls. The AGU abstract adequately and interesting
explains the characteristics in light of it being an EL3 fossil
meteorite with primary, unequilibrated components, with a very sparse
abundance of chondrules.

However, with less than 5 vol% chondrules, how can it be related to the
typical EL chondrites with much higher chondrule percentages of 60-80
vol%? This is still a pretty strange object. At the very least I would
think it should be given an EL3-Anom label. After all, Maralinga was
primarily given its anomalous label because of its higher than normal
chondrule/matrix ratio, although I think its 50 vol% compared to the
typical 15 vol% of typical CKs pales by comparison. The only chondrite
with less than 5 vol% is the CI group (much less than 1 vol%). How did
chondrules become sorted out of the matrix in this one? I await more
scientific insights on this.

A public thanks to those owners of the various masses of this fossil
meteorite who donated material for its in-depth study.

David
Received on Sat 02 Dec 2006 02:28:29 PM PST