[meteorite-list] NWA889

From: Adam Hupe <adamhupe_at_meteoritecentral.com>
Date: Thu Apr 22 10:00:06 2004
Message-ID: <001f01c22704$98110580$ba49e60c_at_attbi.com>

Dear List members,

I have been asked the status of NWA 904 and how it compares to NWA 869, 900
ect.. This is what we have observed so far:

A.) The black clasts are impact melt areas not carbonaceous.
B.) It appears to be a regolith breccia.
C.) Although the chondrules vary in crispness from type 3 to 6 most of them
are type 5.
D.) The crust is totally different than 869 and 900, is not as fresh and has
a rather odd warty texture.
F.) The green diogenite looking clasts are achondritic.
G.) NWA 904 has different zones which show different degrees of weathering
and petrologic type.
H.) I have a sample of NWA 869 and have seen hundreds of kilos of it at the
Tucson Gem and Mineral Show and it is not paired with NWA 904.
I.) NWA 869 looks as if it might be paired to NWA 787, a very nice looking
L6.
J.) NWA 869 has had three different classifications L4, L5 and L6. I guess
it depends on the type samples that were provided to the laboratories. I do
not blame the research labs because most dealers only deposit a 20 gram type
sample. Sometimes this amount of material is not enough to cross the
different petrologic boundaries and thus you can get many classifications
for the same meteorite. Some dealers only send in a portion which they
think will get the best classification, sharp chondrules, less weathering
etc..
K.) Although NWA 900 has black clasts it does not display the zoning of NWA
904, has no green clasts and the weathering is consistent throughout the
stone.
L.) In my opinion NWA 787, 869 and 900 are paired. I have not seen NWA 995
so I cannot comment on its pairing status.

If we had more time we would do a bulk analysis on each of these to once and
for all settle the pairing question. Unfortunately the Microprobe we lease
is booked until September. We are working on some very exciting material
that we are hoping to announce by then. I remember a time when scientist
used scramble at the opportunity to study even ordinary chondrites.

Wishing everybody the best,

Adam Hupe


----- Original Message -----
From: "John Divelbiss" <j.divelbiss_at_worldnet.att.net>
To: <meteorite-list_at_meteoritecentral.com>; "rochette" <rochette@cerege.fr>
Sent: Monday, July 08, 2002 4:17 PM
Subject: Re: [meteorite-list] NWA889


> Pierre and Rob,
>
> Thank you for responses about NWA 900 and 995. Melt, and not carbonacous
for
> 900...that is cool too...since I really like melts. We all look forward to
> more information on these. (Matteo...do you still think you have seen
> achondrite clasts?...in another slice maybe?
>
> Question...has anyone suggested the same(achondrite clasts) for 869? That,
I
> have not heard of.
>
> Greg and Adam...are you out there? What is the status on the "collection
in
> a slice", or NWA 904?
>
> Now I'm (pretty) sure there are achondrite clasts in the 904 slice I
> have...but if I've learned anything is that we should wait for the
analysis.
>
> John
>
> PS Side note...my thin section of 869 from Jeff Rowell looks like I have
an
> L3+ something clast in a L5 or L6 matrix. Probably the slice is a
brecciated
> chunk of L6 clast with a chunk of L3+ matrix in the middle. See how we
get
> turned around. (Al...I used criteria 7 and 8 from page 87 of the "Norton
> Encyclopedia" to come up with my own classification). This is kind of
> fun...but I'll stick to engineering.
>
> PSS Dean...by the way, you do have the best buy out there!
>
> ----- Original Message -----
> From: "rochette" <rochette_at_cerege.fr>
> To: <meteorite-list_at_meteoritecentral.com>
> Sent: Monday, July 08, 2002 12:24 PM
> Subject: [meteorite-list] NWA889
>
>
> > Dear list
> >
> > several pieces from Matteo that were analysed carefully (microprobe, and
> so
> > on) revealed that the clasts are not "exotic" (i.e. carbonaceous or
> > achondritic) but just L6: black is impact melt and gray is moderately
> > shocked, the matrix being L3.8. It remains to be demonstrated that
> Matteo's
> > pieces are really paired with Dean's. The pictures are not so
similar....
> >
> >
> > Pierre
> >
> >
> >
> > ______________________________________________
> > Meteorite-list mailing list
> > Meteorite-list_at_meteoritecentral.com
> > http://www.pairlist.net/mailman/listinfo/meteorite-list
> >
>
>
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Received on Tue 09 Jul 2002 12:53:38 AM PDT