[meteorite-list] ARCTIC IRONS, was Mammoth Stew, etc

From: Jason Utas <meteoritekid_at_meteoritecentral.com>
Date: Mon, 24 Dec 2007 17:00:11 -0800
Message-ID: <93aaac890712241700m114e9cd4jb02274c7450fec32_at_mail.gmail.com>

Hello Sterling, All,
I don't know where you get your .2% figure, but it's wrong.
They may consist of .2% of submitted finds, but I know of at least
forty or so irons that have yet to be submitted, in a number of
peoples' hands.
Out of the five or so thousand meteorites yet submitted, they alone
would constitute nearly one percent, to say nothing of the countless
irons that I have never seen or heard of.
Regards,
Jason

On Dec 24, 2007 4:46 PM, Sterling K. Webb <sterling_k_webb at sbcglobal.net> wrote:
> Hi, Jason, List,
>
> > I would dispute this claim [NWA depletion]
> > ... irons compose ~1.8 percent of finds...
>
> NWA iron finds are 0.2% in contrast to Antarctica's
> 1.8%. Sounds "depleted" (89% depletion) to me. That
> the Antarctic iron find percentage is "typical" of the planet
> is not so absolutely clear cut. Take your pick:
>
> "First, the very strongest meteorite type, metallic iron,
> makes up only about 3 percent of the falls, but at least
> 30 percent of the finds..." -- John S. Lewis, UofAZ
> http://books.google.com/books?id=k9hwi3ktye8C&pg=PA88&lpg=PA88&dq=meteorite+irons+percent+of+finds&source=web&ots=ph81fSImWj&sig=I4xsgM6wBgZ5sgXhOn34Tbi15h0
>
> http://www.amsmeteors.org/fireball/faqf.html
> says 2% of falls and 28% of finds...
>
> http://earthsci.org/fossils/space/craters/met/met.html
> "5.7 percent of meteorite falls are irons."
>
> http://wapi.isu.edu/geo_pgt/Mod05_Meteorites_Ast/mod5.htm
> "only about 3 percent of all observed falls are irons"
>
> http://www.niger-meteorite-recon.de/en/story4.htm
> "The ratio of iron meteorites compared with the
> total number of falls is around 4 percent. As a
> matter of fact the fraction of irons compared to
> the total number of meteorites recovered from the
> African deserts is only 0.2 percent. Until today
> the enigmatic missing of the desert irons is an
> unsolved question. Provided that the pre-Islamic
> inhabitants of the Sahara, like their northern European
> contemporaries, collected and traded meteoritic
> iron as a raw material over longer periods then
> one has an indication for the loss of these irons.
> For in the region of the Air Mountains the first
> iron arrow- and harpoon points are documented
> as early as 2,400 B.C.. Thus there is a period of
> more than 4,000 years until today in which the
> early nomads could have harvested the meteoritic
> iron from its deposits."
>
>
> The American Meteor Society FAQ, posted on
> http://abob.libs.uga.edu/bobk/ccc/cc062398.html
> by Ron Baalke:
> "Meteoroids of asteroid origin make up only a small
> percentage (about 5%) of the overall meteoroid
> population, which is primarily cometary in nature."
> Note that this is "meteoroid," not "meteorite."
>
> http://books.google.com/books?id=DIppUb33M8UC&pg=PA23&lpg=PA23&dq=meteorite+irons+percent+of+finds&source=web&ots=qIif2Elw5U&sig=wd3x_-gSl6QYgrDyDTZIsTAFekg#PPA24,M1
> claims the percentage of iron finds is greater
> in the Western Hemisphere. E. J. Opik's
> "Physics of Meteor Flight in the Atmosphere."
> Tennesse is a good example of the phenomenon.
>
>
> Since we know that irons are preferrentially removed
> by man over historic time periods, it is hard to explain
> any percentage higher than Antarctica's "pristine" and
> ungathered 1.8%. Preferential removal should LOWER
> the percentage, not raise it.
>
> It may be that irons are harder to spot in Antarctic
> glaciated "Blue Ice" environments than stones, or it may
> be that since all Antarctic meteorites are discovered as
> a result of a complicated ice-flow and wind-esposure
> transport interaction that the more dense irons do not
> "transport" as well, or it may be that Antarctica is
> "depleted" in irons for some reason no one's thought
> of yet.
>
>
> Sterling K. Webb
> --------------------------------------------------------------------
> ----- Original Message -----
>
> From: "Jason Utas" <meteoritekid at gmail.com>
> To: "Meteorite-list" <meteorite-list at meteoritecentral.com>
> Sent: Monday, December 24, 2007 5:41 PM
> Subject: Re: [meteorite-list] ARCTIC IRONS, was Mammoth Stew, etc
>
>
> Hola All,
>
> Sterling, you said:
>
> >The distribution (or relative absence) of irons in NWA material shows
> that there is no doubt that the NWA area was "cleaned out" of most of
> the iron meteorites that could be found thousands of years ago. Of
> course, they missed a few. But if the NWA meteorites reflected the
> "normal" distribution of irons and stones, there would be many, many
> more irons.
>
> Based on Antarctic findings, which are supposedly unbiased, I would
> dispute this claim. In the Antarctic, irons compose ~1.8 percent of
> finds, and I see no reason for this to be an incorrect representation
> of fall statistics.
> When looking at fall statistics, one must keep in mind that an iron
> would still be more recognizable than a stone, and as such, would be
> more likely to be picked up.
> Thus, even fall statistics are undoubtedly biased towards irons,
> whereas Antarctic find statistics should be rather more correct,
> rendering this 'Saharan clearing of irons,' although possible, much
> less influential with regard to their percentage of total finds.
>
> Regards,
> Jason
>
> On Dec 24, 2007 3:12 PM, Sterling K. Webb <sterling_k_webb at sbcglobal.net>
> wrote:
> > Hi, All,
> >
> > You couldn't ask for a less likely place to search for iron
> > meteorites than the Canadian Arctic. First, a great deal of
> > Canadian Arctic surficial material was "pushed" far south by
> > those glaciers; there's a nice "car-eating" three-ton chunk of
> > Canada on the road about a quarter-mile from my house (Illinois).
> > Then, there's Bigger-Than-Biblical Floods at the end of glaciations,
> > which would disperse the material remains (meteorites) of an
> > impact. Then, there's those Jack-Daw Humans, picking them
> > all up and using the iron for tools!
> >
> > About four years ago I posted to the List a reference to a paper
> > by a group of archaeologists at one of Canada's national museums
> > (which now I can't find, of course), documenting the distribution of
> > pre-Columbian iron artifacts all across the ancient Eastern Arctic.
> > Analysis of the material used showed that most, but not all of them
> > came from the great Greenland irons (Cape York). Almost found it:
> > short report full of other referrences here:
> > http://adsabs.harvard.edu/full/1988Metic..23R.288M
> >
> > The age of the sites shows that the Greenland irons were being
> > used for tools as early as 1300-1200 BC and the tools from it were
> > spread out over 800 miles away from Cape York! Curiously,
> > this makes the Neolithic North's iron tools pretty much the same
> > age as first iron "tools" (weapons) in the "Cradle of Civilization"
> > (the Hittites), which raises some interesting questions about the
> > meaning of progress, innovation, and that "civilization" thing...
> >
> > Clearly, if iron meteorites from an ancient impact covered that
> > portion of Canada, they would have been used also. If an ancient
> > (33,000 BP) iron impactor had struck the ice cap and was the same
> > compositional type as Cape York, they could be in that material,
> > One of eleven ancient tools recently analyzed was from a different
> > meteorite than Cape York, so we know there was another source in
> > the extreme East Canadian Arctic (not Disko Island telluric iron
> > either).
> >
> > The terrestrial age of Cape York is not known. Buchwald only
> > says it is at least 2,000 years, but could be "10,000's of years."
> > We tend not to think of the giant Cape Yorks as mere cast-off
> > fragments of a bigger impact object, but they could be, of course.
> > If the giant meteorites were being used for tool material, obviously
> > all smaller pieces of the same material would have been used first,
> > before undertaking the effort of beating chunks off the giants. Not
> > an easy task.
> >
> > The distribution (or relative absence) of irons in NWA material
> > shows that there is no doubt that the NWA area was "cleaned out"
> > of most of the iron meteorites that could be found thousands of years
> > ago. Of course, they missed a few. But if the NWA meteorites
> > reflected the "normal" distribution of irons and stones, there would
> > be many, many more irons.
> >
> > Finding any Arctic Canada iron meteorites may be impossible,
> > if you consider that thousands of years of gathering by sharp-eyed
> > locals intimately familiar with the region may have worked the ground
> > first!
> >
> >
> > Sterling K. Webb
> > -------------------------------------------------------------------
> > ----- Original Message -----
> > From: "E.P. Grondine" <epgrondine at yahoo.com>
> > To: <meteorite-list at meteoritecentral.com>
> > Sent: Monday, December 24, 2007 12:32 PM
> > Subject: Re: [meteorite-list] Mammoth Stew, Jason stops
> >
> >
> > Hi Jason, all -
> >
> > Glad to hear you're done. That makes for a Merry
> > Christmas indeed! I and others will be working on
> > possible neutron flux from large hyper velocity
> > impacts over the next few days, and its nice to know
> > that you won't be distracting us with dribble.
> >
> > Now as for your latest nonsense:
> >
> > "But the fact of the matter is that you can't prove
> > "that either an airburst or ice-impact occurred
> > "without, in all likelihood, several years, if not
> > "decades of intense geological field studies, and this
> > "seems to be the point on which our methodologies
> > "differ.
> >
> > Actually, Jason, the isotopic analysis of the IRON
> > PEPPER in the mammoth tusks itself is proof enough.
> > But the recovery of large iron meteorites from the
> > 31,000 BCE iron impact by THE VERY SAME METEORITE
> > HUNTERS who use this list could prove the 31,000 BCE
> > impact to the MOST DENSE.
> >
> > And that is one point where our methodologies do
> > differ.
> >
> > good hunting all,
> > E.P. Grondine
> > Man and Impact in the Americas
> >
> >
> >
> >
> >
> > ____________________________________________________________________________________
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> >
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Received on Mon 24 Dec 2007 08:00:11 PM PST