[meteorite-list] LL7 Chondrites

From: Adam Hupe <adamhupe_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:54 2004
Message-ID: <082c01c412b2$af6c3740$ad971018_at_attbi.com>

Dear List,

I had no idea there could be a transitional 6/7 chondrite because by
definition this goes against the criteria set for a type 7.

According to David Weir's excellent web site the following has to be met:

Chondrules are "poorly defined" in a type 6 and are relics "only" in a type
7. If it has type 6 chondrules how can it be a type 7 as well?

I thought the feldspar coarsens going from type 6 to 7 with those in type 7
being coarser than or equal to .1mm. This requirement seems to state it is
one or the other but not both because there is clear separation. This
separation applies to Howardites on a 10% basis for Diogenitic content. It
is kind of like saying something is transitional between a eucrite and a

How about it David, are there concrete rules regarding this classification.?

All the best,


----- Original Message -----
From: <bernd.pauli_at_paulinet.de>
To: <Mikestockj_at_aol.com>; <mlblood@cox.net>; <meteoritehunter@comcast.net>;
Sent: Thursday, March 25, 2004 12:12 PM
Subject: [meteorite-list] LL7 Chondrites

> > I also have Uden and NWA 969 from MB 88
> Uden was originally classified as an LL6 chondrite
> but McSween, Jr. et al. classify Uden as an LL7.
> Reference:
> McSween, Jr. et al. (1989) Pyroxene thermobarometry in LL-group chondrites
> and implications for parent body metamorphism (Meteoritics 24-4, 1989,
> Best wishes,
> Bernd
> To: Mikestockj_at_aol.com
> mlblood_at_cox.net
> meteoritehunter_at_comcast.net
> meteorite-list_at_meteoritecentral.com
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Received on Thu 25 Mar 2004 04:46:52 PM PST

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