[meteorite-list] Could an impact crater on a meteorite survive passage to earth?

[STARSANDSCOPES at aol.com]

In a message dated 7/18/2007 9:41:54 A.M.  Mountain Daylight Time, 
bernd.pauli at paulinet.de writes:
Stimpy, one of the  rocks seen at Mars Pathfinder's landing site, bears an 
obvious,
circular  depression (arrowed) that some researchers believe to be an impact
crater.  Small meteorites may lie in abundance across the Martian landscape.

A  recent thread raises the possibility of a meteorite on Mars with an impact 
 crater.

I was wondering if this evidence could be found on earth  meteorites or would 
the passage to earth destroy the features of an  impact.

I have a 5+ Kilo NWA unclassified that exhibits a crater looking  feature.  
The crater is about 3cm wide with slightly raised edges and  filled with a 
material that is completely different to all other portions of the  main mass I 
have cut into.  This material is highly shocked embedded into  the main mass.  I 
have cut the feature down the middle an examined it at  high magnification.

The fist guess to the origins of such a feature would  obviously be a 
weathered out inclusion.  It might be just that but it looks  enough like a mini 
impact crater to be interesting.

Email me if you want  some pictures.  I was thinking of doing a Micro Visions 
article on it but I  didn't want to look like an idiot if it is not possible 
for my hole in a rock to  be from impact.

One further observation that supports an impact, on other  portions of this 
meteorite there are rather large areas of dark colored regolith  breccia.  Or 
at least what looks like it.  It is a fine powder  hardened into 50mm and 
larger dark  patches.  I can get detailed  micrographs of the details between 
barred chondrules but I can't get close  enough to bring out the details of this 
fine structure.  Like brown baby  powder hardened with no continuity of 
structure within the areas.   Certainly no chondrule structure.  Think sand only a lot 
 smaller.

Thanks,  Tom Phillips  




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