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

[MexicoDoug 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