[meteorite-list] intriguing Question

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Fri, 11 Jan 2008 01:39:03 -0600
Message-ID: <011901c85425$0a025fb0$795fe146_at_ATARIENGINE>

Hi, All,

> The [S]ahara and parts of the American southwest
> have been dry for a long time...

The American SW, yes. The Sahara, no. It's desertification
began in the eastern Sahara about 14,000 years ago and
worked its way slowly west. Cyrene on the Egyptian-Libyan
border was a flourishing Greek city-state 2700 to 2200 years
ago, then dried up and blew away.

Western North Africa was the "breadbasket" of the Roman
Empire and was still producing agricultural surpluses for
Rome as late as 400 CE. Agriculture was practiced more than
200 miles further inland from the North African shore than
is possible today.

During the most recent glaciation, the Sahara was a bountiful
land with a substantial Neolithic population. Some 8000 to
10,000 years ago, most of the interior Sahara was grassy
plains with scattered forests, lakes and rivers. The present
progressive desertification of the Sahara is irreversible because
of runaway sand generation The Sahara will be a desert now
for millions of years to come, most likely.


Sterling K. Webb
---------------------------------------------------------------------------
----- Original Message -----
From: "Pat Brown" <radio_ranch at yahoo.com>
To: "Jason Utas" <meteoritekid at gmail.com>; "Meteorite-list"
<meteorite-list at meteoritecentral.com>
Sent: Friday, January 11, 2008 12:41 AM
Subject: Re: [meteorite-list] intriguing Question


Hi Jasoon, Peter and the List,

Some thoughts on why the Sahara is so productive:

Another significant factor is the climate over the
past several thousand years. The sahara and parts of
the American southwest have been dry for a long time,
this increases the terrestrial recognizability time of
any meteorites that are there. The sahara has another
interesting and significant factor having to do with
the sand dunes; slowly moving dunes provide a soft
landing and a protective environment as meteorites are
covered by a slow moving dune. Later (sometimes much
later) meteorites are uncovered in great shape with
significant terrestrial age.

Another factor is economic; most of us in the US that
hunt meteorites do so on weekends and vacation time.
Our motivation is to get out in nature and do a bit of
'big science'. Many of the hunters in the sahara are
subsistance hunting, many are truely professional full
time hunters. I get in 25 days of meteorite hunting
tops per year, the locals in the sahara get in well
above 100 days per year in many cases. They have in
many cases spent their lives in the desert. I have
only spent a total of 10 or 12 weeks in the areas
where I hunt. They are better at seeing the odd rock.

A few American hunters that are retired and in good
health likely pass the 100 days per year in the field
hunting mark. I hope to be one of them in 12 or 13
years:)

Pat
--- Jason Utas <meteoritekid at gmail.com> wrote:

> Hola Peter, All,
> I know individual aspect of your questions have been
> addressed, but
> I'd like to as well...
>
> >I know the Sahara desert is about a galgillion
> square miles.
> Then there are the deserts in Calif., South America,
> the Antarctic continent
> and God only knows where else. Why don't I see any
> meteorites from the
> Gobi desert, or maybe the Mongolia desert.
>
> Well, yeah, it's big. But the main reason that
> there are more
> meteorites found in the Sahara than elsewhere is
> because there are
> more people looking. There are just as many martian
> and lunar
> meteorites elsewhere, but they tend to be harder to
> recognize due to
> harder hunting terrain (similar rocks, etc) - and
> because there are
> probably twenty or so meteorite hunters in the
> southwest who get out
> into the wilderness with some frequency - probably a
> few more, since
> Franconia became popular. Compared to the undefined
> number of hunters
> who have been scouring the Sahara for the past
> decade, well, it's just
> not much of a comparison.
> Same goes for South America, though Antarctica has
> seen a good deal of
> thorough hunting, as results would suggest.
>
> >And then there is little dinky Roosevelt Co, NM at
> just 2,455 sq
> miles and it has a
> staggering
> 109 meteorites, which comes to one for every 22.5 sq
> miles. What gives?
>
> This is due to, as has been said, the hunting of
> Skip Wilson, who has
> spent years in the area, hunting blowout after
> blowout with remarkable
> success. A good bit of hunting land paired with his
> diligence has
> turned up pretty spectacular results...
> That said, the density of meteorites that actually
> exist on the land
> should be, at the very least, several per square
> mile; yes, many have
> been found, but there are still countless more
> waiting to be
> discovered.
>
> >They are of a wide variety of classifications, so
> it can't be turning
> every piece in
> for classification. I can't speak for anyone else,
> but I find this
> very puzzling.
>
> I don't see why he couldn't be turning every stone
> in for
> classification; data gathered suggest that smaller
> falls would be more
> common than larger ones, and this would mean that
> the majority of
> falls would consist of small, individual stones.
>
> I also don't know how many of his finds have been
> paired with one
> another, but I have the feeling that if he has been
> concentrating on
> individual areas (as opposed to moving on whenever
> he finds a
> meteorite), it would stand to reason that he has
> found at least a few
> paired meteorites, whether or not they are listed as
> such in the
> catalogue.
>
> Regards,
> Jason
>
> On Jan 9, 2008 7:01 PM, Peter A Shugar
> <pshugar at clearwire.net> wrote:
> > Hello,
> > I'm the newbie, so please explain this to me. This
> is an intriguing question.
> > I can't figure it out. I know the Sahara desert is
> about a galgillion square miles.
> > Then there are the deserts in Calif., South
> America, the Antarctic continent
> > and God only knows where else. Why don't I see any
> meteorites from the
> > Gobi desert, or maybe the Mongolia desert.
> > And then there is little dinky Roosevelt Co, NM at
> just 2,455 sq miles and it has a
> > staggering
> > 109 meteorites, which comes to one for every 22.5
> sq miles. What gives?
> > They are of a wide variety of classifications, so
> it can't be turning every piece in
> > for classification. I can't speak for anyone else,
> but I find this very puzzling.
> > Any thoughts, List?
> > Pete
> >
> > ______________________________________________
> > http://www.meteoritecentral.com
> > Meteorite-list mailing list
> > Meteorite-list at meteoritecentral.com
> >
>
http://six.pairlist.net/mailman/listinfo/meteorite-list
> >
> ______________________________________________
> http://www.meteoritecentral.com
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
>
http://six.pairlist.net/mailman/listinfo/meteorite-list
>

______________________________________________
http://www.meteoritecentral.com
Meteorite-list mailing list
Meteorite-list at meteoritecentral.com
http://six.pairlist.net/mailman/listinfo/meteorite-list
Received on Fri 11 Jan 2008 02:39:03 AM PST