[meteorite-list] Amgala versus Zag

From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:49 2004
Message-ID: <031420041859.3478.58da_at_att.net>

Adam,

Thanx for the update and supporting information for the cost basis. As I said, this fall sure
looks a lot like Zag to me in many ways. I did some more visual comparisons and of course my
untrained eye cannot see these differences when looking at just one one stone's(less than 20
grams) cut face. I am not implying they are the same meteorite...just that they look similar.

As for polymict versus regolith breccia...can these two terms be interchangeable? A polymict
breccia is made up of clasts/fragments of different materials probably caused by a impact
mixing, while a regolith breccia implies a breccia formed at the surface with a mixture of
different materials caused by impacts. A regolith breccia might be considered a special type of
polymict breccia.

As for type 3 chondrules...well I see a few chondrules that look almost perfect to me...but
only a couple. What do I know anyway???

It should be interesting to see how this material is classified out...in comparison to Zag.

John
  
> Hello All,
>
> At first glance Amgala is somewhat similar looking to Zag although there are
> noticeable differences between the two. I do not believe Amgala is going to
> classify as a regolith breccia but rather a polymict breccia. Unlike Zag,
> no type 3 areas have been identified. Two laboratories are currently
> studying Amgala and neither one has observed water bearing minerals but some
> interesting clasts have been found which we will report on later. Another
> party suggested halite because ~10% of the most recently collected broken
> stones show some oxidation on the exposed surfaces. This oxidation is very
> minor and could be removed easily with an air abrasion tool but we chose not
> to in order to preserve these stones in as found condition.
>
> As far as the price dropping into the $5.00 to $7.00 a gram range it is very
> doubtful because there is less than 12 kilograms TKW and a good portion has
> already been sold to collectors for between $7.50 a gram for fragments and
> $12.00 a gram for fully crusted specimens. The seventh and final trip to
> the area by the Moroccan half of Team LunarRock only produced five stones
> making it less than cost effective to return to the region. All indications
> are that this is a very small fall with precious little more material coming
> out. After all, nomads avoid this area and soldiers have been methodically
> searching it for months now. Only the soldiers know which areas are safe
> and which are not and they are done searching because of the lack of new
> finds associated with this fall.
>
> We rang up a tremendous amount of expenses pursuing this fall including
> communication, transportation, specimen purchases, sample material,
> supplies, shipping and lab fee costs. 26% of the recovered stones we paid
> the high field price for turned out to be a black chondrite not related to
> this fall. This increased our acquisition costs by nearly the same
> percentage. Pursuing Amgala was an expensive undertaking. Was it worth it?
> Yes, this is some very handsome material with the nicest jet-black velvety
> crust I have seen not to mention the contrast provided by the polymict
> breccia texture.
>
> We will update as lab results come in which promise to be interesting.
>
> All the best,
>
> Adam
>
>
>
> ______________________________________________
> Meteorite-list mailing list
> Meteorite-list_at_meteoritecentral.com
> http://www.pairlist.net/mailman/listinfo/meteorite-list
Received on Sun 14 Mar 2004 01:59:15 PM PST