[meteorite-list] Northwest Africa Falls - Question

From: Jeff Kuyken <info_at_meteoritecentral.com>
Date: Mon, 19 Jan 2009 19:23:54 +1100
Message-ID: <789377F406144E61BB9140A4DBD9FE18_at_JeffPC>

I would tend to agree with the opinions so far but whether you can use
freshness as a justifiable reason to call it a find... well... that
difficult job is yours Jeff! ;-)

I also thought most of these falls had pretty reliable fall evidence as some
have mentioned. Also... wasn't Oum Dreyga witnessed and collected by the
Western Saharan Military?

I purchased a small "Amgala" (Oum Dreyga) individual from Mike Farmer's very
first 1kg batch out of Morocco. It is without equal in all the other falls I
have. Bensour is a close second but the Oum Dreyga has thick, rich fusion
crust like soot that you would expect to rub off on your hands.

Cheers,

Jeff


----- Original Message -----
From: "Michael Farmer" <meteoriteguy at yahoo.com>
To: "Meteorite-list" <meteorite-list at meteoritecentral.com>; "Jeff Grossman"
<jgrossman at usgs.gov>
Sent: Monday, January 19, 2009 5:01 PM
Subject: Re: [meteorite-list] Northwest Africa Falls - Question


> Jeff
> I completely disagree with calling Bensour a find. The
> information/story/newspaper articles are more data than we have for many
> finds. Take Bilanga, there is nothing in the news, no reports other than
> missionary people taking out stones. Of course it is a fall, the people
> all saw it, and fresh stones were everywhere. Why is Bensour any
> different? I still have hundreds of Bensour stones, I have the main mass,
> 10 kilograms, the soft velvety fusion crust on many stones still have the
> iridescent sheen only seen in falls with no rain ever touching them. The
> sand blowing there would have damaged the crust in days, the sub 200 mg
> stones would never be found on an old fall. I have vials of them, most
> oriented. I think Bensour was pretty well documented.
> Would be glad to send you some pieces to check, but you will find not the
> slightest hint of weathering on any piece.
> Michael Farmer
>
>
> --- On Sun, 1/18/09, Jeff Grossman <jgrossman at usgs.gov> wrote:
>
>> From: Jeff Grossman <jgrossman at usgs.gov>
>> Subject: Re: [meteorite-list] Northwest Africa Falls - Question
>> To: "Meteorite-list" <meteorite-list at meteoritecentral.com>
>> Date: Sunday, January 18, 2009, 8:22 AM
>> Please don't misunderstand me... I just said there was
>> reason to be suspicious from a statistical point of view,
>> and of course there is an obvious financial motive. But I
>> was not saying that I thought any of the fall stories were
>> false, since I never even tried to assess them.
>>
>> So let's see if there is consensus to be found here on
>> these recent falls. I did a simple reading of the fall
>> accounts and used google scholar to search for cosmogenic
>> nuclide or other supporting data. Here are my zeroth order
>> ratings of each fall story:
>>
>> Chergach - highly likely
>> Bassikounou - highly likely
>> Benguerir - probable
>> Beni M'hira - probable
>> Bensour - questionable
>> Oum Dreyga - questionable
>> The new one - nothing to evaluate
>> Maigatari-Danduma - ignore since it isn't really in the
>> NWA region
>>
>> Bensour is such a weak story that I'm leaning towards
>> changing it from a fall to a find in my database, which is
>> basically what the MetBull article also said. I'm not
>> even sure how it got listed as a fall. Do any of you take
>> issue with this?
>>
>> The Oum Dreyga story also has strange elements. The
>> witnesses saw it "falling on ... [the] mountains,"
>> which probably means that if there was a real fall, it was
>> very distant. The fact that many of the stones were
>> weathered also raises my doubts. So I rate this as weak.
>> Anybody want to take the stand on Oum Dreyga's behalf?
>> Or argue against any of the ones I called probable or highly
>> likely?
>>
>> If two are really finds and one is eliminated because it is
>> really not in this region, then we are left with 4 in the
>> 2000s decade, plus the new one which remains to be seen.
>> Four is certainly a more palatable number than eight from a
>> blind statistical point of view, neglecting other
>> sociological factors.
>>
>> Jeff
>>
>> Dr. Svend Buhl wrote:
>> > Interesting debate. Reminds me on the good old days of
>> the Acedemie Francaise, the days before Biot and Chladni,
>> where scientists doubted the accounts of local eyewitnesses
>> on rocks falling from the skies for sociological reasons.
>> >
>> > As far as I am concerned, I still trust the people who
>> measured e.g. the cosmogenic radionuclides of the meteorites
>> produced by these recent falls. I absolutely doubt that the
>> Swiss or French labs who worked on these stones made up
>> their results just to make them fit the newspaper reports
>> and eyewitness accounts.
>> >
>> > Svend Buhl
>> >
>> >
>> > ----- Original Message ----- From: "Jeff
>> Grossman" <jgrossman at usgs.gov>
>> > To: "Meteorite-list"
>> <meteorite-list at meteoritecentral.com>
>> > Sent: Saturday, January 17, 2009 11:27 PM
>> > Subject: Re: [meteorite-list] Northwest Africa Falls -
>> Question
>> >
>> >
>> >> Martin and list,
>> >>
>> >> Actually, there is something suspicious.
>> Northwest Africa (the countries you listed plus Western
>> Sahara and Tunisia) has seen between 0 and 3 falls per
>> decade from the 1900s through the 1980s. The 1990s saw 6,
>> and the 2000s have now got 8. There is no parallel increase
>> in the rest of Africa, which in fact has been steadily
>> declining in fall rates since the 1940s. Europe has also
>> been declining since the 1930s (in fall rates), as has North
>> America. I think northwest Africa is the only place in the
>> world that is seeing any kind of increase in rate, and it
>> has been dramatic, tripling in the last decade.
>> >>
>> >> The are various sociological reasons why this
>> increase might have happened, which we can argue about. But
>> there certainly IS something to raise ones eyebrows.
>> >>
>> >> Jeff
>> >>
>> >> Martin Altmann wrote:
>> >>> Hi Ryan,
>> >>> it's because of the iron mountain in
>> Atlas, which still has to be found and
>> >>> which attracts with his magnetic field all
>> iron-bearing lumps from space.
>> >>>
>> >>> No. Take a World map, hold little Europe
>> (forget a little bit about
>> >>> Scandinavia),
>> >>> hold it against that NWA region, Algeria,
>> Mali, Niger, Morocco,
>> >>> Mauretania....
>> >>>
>> >>> And let's count the falls:
>> >>>
>> >>> Let's start with Zag 1998.
>> >>>
>> >>> NWA-Regions:
>> >>>
>> >>> Zag 1998
>> >>> El Idrissa 1998
>> >>> Djoumine 1999
>> >>> Beni M'hira 2001
>> >>> Bensour 2002
>> >>> Oum Dreyga 2003
>> >>> Maigatari-Danduma 2004
>> >>> Benguerir 2004
>> >>> Bassikounou 2006
>> >>> Chergach 2007
>> >>> And now the new possible fall.
>> >>>
>> >>> Europe:
>> >>>
>> >>> Ourique 1998
>> >>> Leighlinbridge 1999
>> >>> Moravka 2000
>> >>> San Michele 2002
>> >>> Neuschwanstein 2002
>> >>> Alby sur Cheran 2002
>> >>> Villalbeto 2004
>> >>> Moss 2006
>> >>> Puerto Lapice 2007
>> >>> Romanian Fall 2008
>> >>>
>> >>> 11 : 11.
>> >>>
>> >>> So nothing suspicious.
>> >>>
>> >>> USA had 7
>> >>> India 10
>> >>>
>> >>> Best!
>> >>> Martin
>> >>>
>> >>>
>> >>>
>> >>>
>> >>> Ok Folks,
>> >>>
>> >>> I am curious to know why there are so many
>> witnessed (recovered) meteorite
>> >>> falls in Northwest Africa as opposed to
>> anywhere else in the world. Is there
>> >>> a good logical and/or scientifc explanation
>> for this?.. or just a
>> >>> coincidence? I understand that some
>> "falls" simply turn out to be a case of
>> >>> Nomadic lies in an attempt to liquidate
>> (recycle) old material, but what
>> >>> about the others? Perhpas it has something to
>> do with it's geographical
>> >>> location in relation to..?
>> >>> And yes, I do understand these people spend
>> countless hours outdoors, in the
>> >>> desert, ect. but..
>> >>>
>> >>> What are your thoughts?
>> >>>
>> >>> Ryan
>> >>>
>> >>>
>> >>>
>> ______________________________________________
>> >>> http://www.meteoritecentral.com
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>> >>> Meteorite-list at meteoritecentral.com
>> >>>
>> http://six.pairlist.net/mailman/listinfo/meteorite-list
>> >>>
>> >>> ______________________________________________
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>> >>>
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>> >>>
>> >>>
>> >>
>> >>
>> >> -- Dr. Jeffrey N. Grossman phone: (703)
>> 648-6184
>> >> US Geological Survey fax: (703)
>> 648-6383
>> >> 954 National Center
>> >> Reston, VA 20192, USA
>> >>
>> >>
>> >> ______________________________________________
>> >> http://www.meteoritecentral.com
>> >> Meteorite-list mailing list
>> >> Meteorite-list at meteoritecentral.com
>> >>
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>> >
>> > ______________________________________________
>> > http://www.meteoritecentral.com
>> > Meteorite-list mailing list
>> > Meteorite-list at meteoritecentral.com
>> >
>> http://six.pairlist.net/mailman/listinfo/meteorite-list
>> >
>>
>>
>> -- Dr. Jeffrey N. Grossman phone: (703) 648-6184
>> US Geological Survey fax: (703) 648-6383
>> 954 National Center
>> Reston, VA 20192, USA
>>
>>
>> ______________________________________________
>> http://www.meteoritecentral.com
>> Meteorite-list mailing list
>> Meteorite-list at meteoritecentral.com
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Received on Mon 19 Jan 2009 03:23:54 AM PST