Hi Martin, list,
NWA 3163 IS paired with NWA 4483 and 4881 (Korotev & Met. Bull.).
All the other unpaired from your compilations are correct.
This being and, on another note, because NWA 4483
was quasi certified having been found in Algeria
(Ralew and also Met. Bull. database), I guess it
is also so with its two pairings?
In Met. Bull. database, both NWA 3163 and NWA
4881 are reported coming from "Algeria or Mauritania".
Wouldn't it then be right to claim that all three come from Algeria ?
Would this conclusion hold based on an as simple statement ?
Not sure....
Let's now consider more in depth the above (rather simple) pairing issue.
Here are the purchase circumstances for the three
paired meteorites (MetBull database):
NWA 3163: Purchased by Hupé in Ouarzazate, in 2005
NWA 4483: Purchased by Ralew in Erfoud, in 2006
NWA 4881: Purchased by Ralew in Ouarzazate, in 2007
This suggests that a Lunar found "somewhere
between Mauritania and Algeria" or "somewhere in
between ?" (these 2 countries do share a common
border), pre 2005, was brought to Ourzazate where
sold to two different dealers (probably by two
different vendors) in an interval of two years,
while the same meteorite was also sold (probably
by a third person) to Ralew in Erfoud in 2006.
Excellent example of a meteorite walking from one
vendor to another, from one place to another,
with time, to finally reach different dealers.
Whatever it be, it is amazing that science is
today able to (start to) reconstitute (partly)
this meteorite and define its identity and status
from an independent sophisticated analysis of the
3 NWA samples that wandered independently in
space and time, ending up independently in the
basket of different dealers who gave it for
classification to different institutes, who
eventually came into conclusion that it is the
(probably) the very same meteorite.
This is a real performance and confirms that Greg
Hupé is right when he decides to have every
fragment of an important meteorite probed for its O isotopic abundance.
But...what a waste of time and money!
Wouldn't it be far more simple that once a
meteorite is found, all the fragments are
assembled by the finder and sold (or distributed
among other vendors) under the same provisional
code until it is eventually classified ?
We all know (from our early debating this topic)
that this is totally illusory because money and
personal interests would predominate over scientific interests.
And, by the way, the "almost happy end" regarding
this Lunar pairing issue was likely because it is
a Lunar that is often readily classified by
institutes.....but this possibly suggests that
most of the NWA ordinary chondrites (or even
achondrites) will never get the chance to have
their pairing status defined, simply because it
is less interesting to study them.
This perhaps explains the large number of NWA's
found and their relatively low tkw's....
Large speculative debate....
Take care,
Zelimir
At 01:07 29/09/2010, you wrote:
Though I wrote it privately... ;-)
But especially the lunars and Martians, which are always checked, if they
are paired,
there one can see well, that there is no rule, that no stone comes alone
from NWA.
Some have immediate pairings, from some every few years another sample
surfaces,
others there suddenly after a long break of many years more comes to light.
So far unpaired NWA-Martians are:
NWA 817
NWA 856
NWA 998
NWA 1195
NWA 1669
NWA 1950
NWA 2046
NWA 2626
NWA 2646
NWA 2737
NWA 2800
NWA 3137
NWA 4222
NWA 4468
NWA 4480
NWA 4797
NWA 5029
NWA 5289
NWA 5718
NWA 5789
NWA 5990
NWA 6162
So from the 28 different NWA-Martian, there are only 6 which build up a
pairing group.
22 are unpaired.
Moon:
Unpaired:
NWA 482
NWA 2200
NWA 2998
NWA 3163
NWA 4734
NWA 4819
NWA 4884
NWA 4898
NWA 4932
NWA 5000
NWA 5153
NWA 5207
NWA 5744
(The NWA 773 - Anoual I lumped together)
So there 13 out of 19 unpaired.
Well, and as far as the general rareness of NWAs compared to historical
finds/falls is concerned.
To me it seems, that the NWAs in general - also if you take paired numbers
together - have on average a much smaller tkw than non-desert-finds. Well
one would need some ling winter-evenings to verify that.
Though sometimes - tiny fragments, without any crust, non-magnetic
achrondites - e.g. some of the Martians from the NWA 2975 - or if you
remember the tiny peas of the NWA 1068 group, looking like sandstone.
For me it's a sheer riddle, how you can find such pieces at all!
Crawling on my knees through the field, I wouldn't find them.
Or cause we just had it NWA 4485, NWA 4472 - all around a fat weathering
crust, white like chalk.
Who the heck would ever pick up such a stone from the field and suspect it
to be a meteorite?
It is truly amazing, what the hunters do down there.
Best!
Martin
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
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