[meteorite-list] Anomalous and Ungrouped Ordinary Chondrites

From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:28:32 2004
Message-ID: <101920032148.7259.6d57_at_att.net>

Hello all,

I've always been intrigued but puzzled about the classification of a few
ordinary chondrites into the black hole of assigned classification
names...ungrouped and/or anomalous. Some are specified with petrologic
assignments and others without. Ebay on occasion offers us Hah 180 that is
classified as an anomalous 3.5 ordinary chondrite and Dhofar 535 that is
classified as ungrouped, and without a petrologic designation in its'
description. According to David's site below...Hah 180 is similar to Deakin
001. And there maybe others I am not thinking of. Oxygen isotopes and
weathering seem to be some of the key factors...and as stated on David's site
they may come from a proximity close to where enstatite chondrites were
formed, and in my opinion their appearance makes them at least look like some
of the EL3's out there.

Does anyone know what the latest theory is for these and will they one day
get an official LL3 to 3.5 anomalous label which would finally give them a
home? Seems to me to call them anything else puts them/keeps them in
classification limbo.

http://www.geocities.com/dgweir/HAH180.HTM

Just curious,

John
Received on Sun 19 Oct 2003 05:48:26 PM PDT