[meteorite-list] Mt. Egerton

From: David Weir <dgweir_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:33 2004
Message-ID: <3B59C841.F7ECD49B_at_earthlink.net>

Hello Dave and Mike,

I think it's also practical to rethink the terms chondrite and
achondrite as useful classification parameters. We now have the
achondrite acapulcoite NWA 725 (Tissemoumine) which has distinct
chondrules, along with relict chondrules in Monument Draw. And there are
a few carbonaceous chondrites that have experienced complete aqueous
alteration of their chondrules to the point of obliteration (an aqueous
achondrite?). And what about chondrites that have not experienced
igneous conditions, but instead have been totally recrystallized by the
heat of impact, sometimes classified as petrologic grade 7 (an impact
achondrite?).

But just as we can choose to use the relatively general term
mesosiderite, it's really a matter of how detailed the information is
that you wish to convey. A simple division into stones, irons, and
stony-irons may suffice for some situations, but even the option to
split the classification scheme into unique parent bodies is becoming
more possible each year.

Regards,

David
Received on Sat 21 Jul 2001 02:21:53 PM PDT