[meteorite-list] The most beautifull fresh and oriontedpallasiteever seen

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Wed Jan 25 11:50:36 2006
Message-ID: <22c.546ecaf.3109055f_at_aol.com>

Images: #36, #44, #48, #53 (53-flow lines, leading edge, and/or wire brush?)
seem to show a minimal orientation to me, if you compare the leading faces
to the flattened back.

Could there be a weak argument for some signs of orientation? Still, I'd
agree in principle with Mike, there are far better examples of orientation out
there! BTW, 'oriented' isn't exactly the word used to describe it: maybe it
is only claimed to be from the constellation of Orion? :-) Hey, if she
happens to be the most beautiful girl ever seen, but is she crying?
cryyyyying.....? (crying=lawrencite) Just as Mike has a beef with oriented exaggerations,
I believe many specimens' freshness is exaggerated. A slice of bread with a
 small amount of mold isn't fresh just because it still hasn't rotted away
(it still should at least have its crust or for stonys fresh breaks). Where is
 the trademark bluish patina or coloration of burnt steel for a fresh iron?

We get to see truly beautifully oriented Sikhotes, as text-book examples of
oriented specimens. I wondered whether the low altitude they exploded at,
combined with the large crystal bandwidth helped preserve more of the bullet
and shield shapes. A larger incoming mass maintaining its integrity has a
great chance to develop deep regmaglypts which could theoretically "disorient"
the bolide by disrupting the aerodynamic flow. Not only might the Sikhote Alin
fall have experienced more uniform ablation due to the greater uniformity
and size of the Iron-nickel crystals, and lack of inclusions, but it exploded
at what might be considered an optimum altitude to dissipate a lot of energy
and expose the fragments for just the right amount of time in a denser
atmosphere where the burnishing was probably as incredible as it was quickly damped.
This could not have happened with smaller pieces entering from higher
altitudes, they might turn into cinders before reaching the ground. Maybe someone
could comment on whether regmaglypts develop on leading faces of oriented
masses after long, energetic reentries, or whether regmaglypts solely are the
result of smoothing out crevices and irregular shapes in disoriented
reentries.

Is a classification of orientation only for two possibilities, presence or
absence? So if it is not oriented, then is it supposed to be disoriented? A
randomly tumbling mass might have no symmetry at all, but in nature wouldn't
there be a subjective distinction, when you get possibly parallel or not,
one, two, or three principal axes causing symmetry?

Back to Mike's thoughts, I would agree with his opinion that if you have to
work hard to find evidence for the axes of orientation, while it is a fun
specimen to study, it is really not something personally that would be
especially interesting or more valuable for where's Waldo type of "orientation", but
rather for its other impressive attributes...

Saludos, Doug



Marcin C. writes:
> Aziz, first, that IS NOT A PALLASITE,

Mike, list,
I only forward this email, but from photos I cant tell what it is. For sure
Iron. There should be photos with bigger resolution than offered by Yahoo to
see all details.

> it is an iron. Second, it IS NOT ORIENTED.

I think You are wrong. It is highly regmaglypted from one side and flat,
from another. It can be oriented. Have 2 verry different crust surfaces.

> It is a beautiful iron, it is not a pallasite, and it does not show the
> slightest sign of flight orientation, but it does show nice regmaglypts.
> Mike Farmer
Received on Wed 25 Jan 2006 11:46:23 AM PST