[meteorite-list] status of NWA brachinites

[Zelimir Gabelica]

Dear Ted,

Many thanks for the link.
The paper by Rumble et al. (you included) is very instructive and (if I 
understood well), although not conclusive regarding the BRA parent body 
(unique or not), at least it throws much more light on the other properties 
that are different (but not necessarily oxygen isotopic data), for at least 
the 4 brachinites cited (NWA 4872, 4874, 4882 and 4969), concluding that 
they are (possibly ? probably?) not paired.

On the other hand, pairing of NWA 5199 and 3151 was suggested (Met. Bull. 
database).

As for NWA 595, it also seems to be a unique and different meteorite (do I 
conclude correctly by saying that it might even not be a brachinite since 
it is related, at least taking into account the 17O data, to Zag(b) and NWA 
4042 (respectively "Acungr"  and "BRA" (Met. Bull), although data for the 
latter might have been updated since ?)
My question is here very similar to the conclusion Steve Arnold #1 sent 
realier today to the list as post.

At least I am aware that the BRA-type meteorites evoqued here are still 
puzzling and not evident to identify unambigously.

I also read with great attention the dozen or so other papers you mentioned 
in the link, related to other classifications and all of them are indeed 
very informative, even if sometimes not fully conclusive (which is what we 
so often must conclude from scientific research).

Again, as for Steve Arnold, my questions here basically originate from a 
collector's point of view, meaning that we are also concerned with 
meteorite accurate types and their belonging (or not) to group(let)s.
In other words, with their as accurate as possible classification.
This does not mean that we don' appreciate the important science and 
research that is behind, without which not any classification could be 
proposed.

Thanks again,

All the best to all,

Zelimir


A 08:09 02/12/2008 -0700, Ted Bunch a écrit :
>Dear Zelimir please see below for at least one answer.
>
>Ted Bunch
>
>
>On 12/2/08 7:20 AM, "Zelimir Gabelica" <Zelimir.Gabelica at uha.fr> wrote:
>
> > Hi Martin,
> >
> > I fully agree.
> >
> > To be complete, here is what I have in my archives:
> >
> > ..."NWA 4969 (BRA, Algeria, tkw = 1 at 180 g) from Marcin, is paired with NWA
> > 4882 (Algeria, from Hupé's, BRA, tkw = 2@ 3096 g), but apparently not with
> > NWA 3151 (BRA, Hupé's, tkw = 1 at 1500 grams), nor with NWXA 5191 (1 at 26.5 g)
> >
> > With  the new NWA 5471 from Heir's, this indeed makes 4 brachinites from
> > the "NWA" vast strewnfield.
> >
> > However, in Met. Bull. database, we find the following brachinites from
> > "NWA", this better completing the picture:
> >
> > NWA 595 (Cottingham, Morocco (?), 1 at 196 g)
> > NWA 3151 (Hupé's, NWA (Morocco ?), 1 at 1500 g)
> > NWA 4872 (Aaronson, Algeria, 1 at 3000 g)
> > NWA 4874 (Aaronson, Algeria, 1 at 28 g) (can it be paired with NWA 4872 above
> > ???) NO, please go to 
> <http://www4.nau.edu/meteorite/index.html,>http://www4.nau.edu/meteorite/index.html, 
> click on BRACHINITES and see for yourself.
>
>
> > NWA 4876 (anonymous, NWA ( Morocco ?), 1 at 130 g
> > NWA 4882 (G. Hupé, Algeria, 2 at 3096 g)
> > NWA 4969 (M. Cimala, NWA (Morocco ?), 1 at 180 g
> > NWA 5191 (anonymous, found in Morocco desert, 1 at 26.5, said to be paired
> > with NWA 3151, thus suggesting this latter was also found in Morocco
> >
> > NWA 5471 (C. Heir's, Morocco (??), 1 (??)@538 g, paired with ???? (not yet
> > in Met. Bull.)
> > ----------
> > Total: not copunting pairings, we find 9 different meteorite names (NWA
> > numbers), probably 10 separate pieces, totalling 8694,5 grams
> >
> > Question: How far are these data (Met Bulll database + NWA 5471) correct
> > and complete ?
> >
> > Who can complete, possibly remove the ???'s and add comments about
> > pairings, so that we all can update our archives regarding NWA brachinites?
> >
> > Bernd? Greg ? Marcin ? Martin ? or Jeff ?
> >
> > Thanks and best wishes,
> >
> > Zelimir

Prof. Zelimir Gabelica
Université de Haute Alsace
ENSCMu, Lab. GSEC,
3, Rue A. Werner,
F-68093 Mulhouse Cedex, France
Tel: +33 (0)3 89 33 68 94
Fax: +33 (0)3 89 33 68 15