[meteorite-list] NWA 869

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Tue Jun 14 12:31:47 2005
Message-ID: <1f5.bbd7d06.2fe06068_at_aol.com>

Hola Michel,

That is quite an enlightening story that is most fantastic though also
disheartening.

Based on the "coordinates" you published in Met. Bulletin #88, it seems that
the strewn field is of the order of 1500 to 2000 square kilometers - perhaps
5 or 10 times larger than that of the 1969 Mexican fall over el pueblito de
Allende, much larger than Sikhote-Alin, Toluca and Campo del Cielo, if I
understand the way the minutes are expressed in the publication. Could you very
kindly tell us how much the Area [I am sure you know the formula but I put it
here for others interested in this] approximates = the NET product of
(Pi/4)x(long axis)x(short axis)?, example 3.14/4x(40km)x(60km) = 1885 km2

I don't think any other meteorite strewn field has been documented to be
this size - twice the size of metropolitan Paris ... it even sounds surrealist
for me to imagine.

Hopefully your pioneering field work on this great, relatively fresh and
incredibly beautiful Sahara 02500 will be recognized as one of the finest field
works of all time when things become more friendly for meteoritically driven
kind nomads like you.

If nothing else we can all visit back there as friends and the help of the
touch of a kind snake we meet in the desert...

Saludos, Doug

Michel F. wrote:
Hi list, Hello Jeff,

Interesting topic.

I am the one that had 410 kg classified as Sahara 02500. L3.8 etc...
I have the coordinates of the 64 first individuals found. ( And I have
drawn the ellipse of the fall. For many reasons I choose not to disclose
the coordinates.) The people working for me searched and found more, on
the field 3 times. We gave to the Nom Com a full report of our work. It
was partially published.

On the same field we recovered also other meteorites. It is almost very
easy to visually identify it from other meteorites. When I have doubt I
used a SM30 to mesure the magnetic susceptibility of the specimen. It' s
a good cross check, not an anlayse. I will not be surprised that other
teams went on the field to recover more, as we had no exclusivity of any
search in the Sahara. It could be what is commonly called 869. From
what I have seen in different shows, Sahara 02500 and 869 look pretty
similar. I don't know, as I never tested a 869 specimen with the SM 30,
nor had any accurate location for the 869. I will argue that i am not
interested in trying a pairing with meteorites that I have not
recovered, knowing all sorts of discussion about pairing that we had on
this list and elsewhere too.

I discussed that with Ted Bunch in Tucson. He made a compementary study
on some big inclusions that are commonly found in this meteorite and he
was surprized that he could not publish it because 869 has never been
published! He should have made his work from my samples ! We had a good
laugh. About these inclusions, some are chondritic, some achondritic,
but it very rare to find achondritic material in it, according what I
know today.
Received on Tue 14 Jun 2005 12:31:36 PM PDT