[meteorite-list] TAMEDAGHT PHENOMENA - more enigmatical examples

From: Martin Altmann <altmann_at_meteoritecentral.com>
Date: Sat, 2 May 2009 19:59:07 +0200
Message-ID: <001701c9cb4f$b0bb2740$177f2a59_at_name86d88d87e2>

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/





 


 


 
Received on Sat 02 May 2009 01:59:07 PM PDT