[meteorite-list] TAMEDAGHT PHENOMENA - more enigmatical examples

From: cdtucson at cox.net <cdtucson_at_meteoritecentral.com>
Date: Sat, 2 May 2009 11:54:47 -0700
Message-ID: <20090502145447.4TKUH.45038.imail_at_fed1rmwml33>

Martin and list,
 
"Well, Nel's idea, that ablated material was following the backside of a
meteorid, quasi in a vacuum tunnel, I can't imagine. "

I am certainly no expert either but, this point Nel makes brings to mind a theory about the Carancas fall that sounds similar.
During the time of the Carancas fall someone posted ( I believe it may have been Jan) that they had a fully crusted example. Well, I have three more such examples. Apparently these too are very rare. It was suggested to me by a Russian Scientist ( I lost her name for the moment) that this may suggest that these (now four) individual falls did fall in a sort of "swarm" and not as a single meteorite after all. She suggested just as Nel does now that these road piggy back with the big one in a vaccum. To her this was the only way to explain it given that they also ended up landing in the same general area as the bigger one that exploded on impact. You would think smaller ones don't travel as far.
On the other theory, as I recall extreme heat upon impact was never totally ruled out either with Carancas. As the water in well did boil for reasons yet unproven beyond doubt.
In sum, I would like to thank you Martin and Aziz as well for not rejecting this material as many others would have. And for the great pics. This is very cool stuff.
My two cents.
Carl Esparza
IMCA 5829

---- Martin Altmann <altmann at meteorite-martin.de> wrote:
> Good day list members,
>
> after the digressions of the last days, how about turning back to
> meteorites?
>
> Stefan made meanwhile some photos of more of these baffling "products" of
> the Tamdaght fall.
> As implausible they might seem to be, they do exist!
>
> Here we have some examples, which demonstrate hopefully quite well the
> different forms of appearances of this strange objects, which contains
> real fusion crust; preserved fragments of the meteorite with and without
> crust; a bubbly material looking like an impact-melt and some glassy
> melt(?).
>
>
> In that piece you can observe without doubt lots of true fusion crust,
> rounded and ball-shaped as it almost would be a conglomerate incorporating
> tiny individuals. To the right some of the foamy material and some of that
> glassy "melt":
> http://www.chladnis-heirs.com/vip/tamdaght-melt1.jpg
>
>
> The other side reveals that the piece is composed of so many tiny fragments,
> sometimes covered with fusion crust. Sticking or "glued" together.
> http://www.chladnis-heirs.com/vip/tamdaght-melt2.jpg
>
>
> Here a even more striking example, for this strange composition,
> where numerous and crustless sharp meteorite fragments adhere to each other:
> http://www.chladnis-heirs.com/vip/tamdaght-melt4.jpg
>
> Well, best meets the word the gentleman, who initially presented us that
> material, the appearance, when he described it as "couscous".
>
> Back, with some crust and that vesicular material with the large bubbles,
> which we know in the field of meteorites only from impact melts:
> http://www.chladnis-heirs.com/vip/tamdaght-melt5.jpg
>
>
> There a somewhat coarser part of the conglomerate. With light-coloured
> fragments of the meteorite...
> http://www.chladnis-heirs.com/vip/tamdaght-melt3.jpg
>
>
> Last example:
>
> http://www.chladnis-heirs.com/vip/tamdaght-melt6.jpg
>
> http://www.chladnis-heirs.com/vip/tamdaght-melt7.jpg
>
> These "coglomerates" btw. are not very friable or crumbly,
> hence not simply condensed fragments, glueing together through the
> mechanical pressure of an impact with normal fall velocities.
> (Nor any humidity was involved, hence no dried dirt is the gluing agent).
>
>
>
> Amazing, isn't it?
> And there the problem starts, we have these samples, but how to explain the
> formation?
>
> Tamdaght, after all we know so far, was a "normal" meteorite fall. The
> pieces retrieved, fragments and entire individuals, show no exceptional
> features, especially regarding fusion crust, which would indicate any
> uncommon event.
> Nothing points to a different course of the event, as we know from the other
> stone falls.
> Hence it was no hypervelocity impact, fragmentations in air must have
> happened within the usual parameters, the stones felt with normal resulting,
> terrestrial velocities.
> Neither any signs of an impact with still partially cosmic speed at the
> impact site are found.
>
> Such a fall shall not create any melts, glasses or shock effect while
> impact.
>
> And though, there are these strange samples.
>
>
> I personally am an adherer of "cold falls". I don't believe in stones being
> remarkably hot hitting the ground, especially not so hot, that they could
> melt or fuse from their temperatures of their surfaces the medium they hit.
>
>
> Well, Nels' idea, that ablated material was following the backside of a
> meteorid, quasi in a vacuum tunnel, I can't imagine.
> (having said, that I'm no expert...)
> ... would suppose, that the speed the meteorid owns in that phase of flight,
> where its surface isn't directly ablated anylonger but melting wouldn't be
> fast enough to create a vacuum-like slip stream?
> But especially not, after the meteorid has fully lost its initial speed and
> it passes into normal fall velocity, travelling still several miles in the
> cold Sea of air, before it hits the ground with the speed of a racing car.
> Hence hot, the material couldn't have arrived,
> - rewelded from the effluent melt in flight - that can't explain, why there
> are so many intact meteorite fragments preserved in these specimens.
>
>
> Perhaps Stefan's idea could carry on the discussion?
> He points to his observation, that on the backside of oriented individuals,
> sometimes small fragments accumulate,
> like on the back of this Bassikonou from his collection:
> http://www.chladnis-heirs.com/vip/bassi-orin.jpg
>
> But the problem with the impact-melt looking material inbetween the
> fragments remains,
> as extremely high pressures are necessary to create impact melts.
> If one has to work with in-air-collisions.....
>
>
> Fact is, that material is absolutely unique.
> We're not aware, whether similar material was found with other stone falls
> and might it remain inexplicable for a longer while,
> we think, it is well worth a profound research.
>
>
> Best Regards,
> Martin Altmann & Stefan Ralew
>
>
>
> Chladni's Heirs
> Munich - Berlin
> Fine Meteorites for Science & Collectors
>
> http://www.chladnis-heirs.com/
>
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Received on Sat 02 May 2009 02:54:47 PM PDT