[meteorite-list] Meteorite Questions (square craters)

[Charles O'Dale]

It is a "jointed crater", determined by the geology of the area of impact.

http://science.nasa.gov/headlines/y2000/ast26sep_1.htm

Chuck

> Date: Thu, 30 Aug 2007 01:14:27 -0700
> From: "Jason Utas" <meteoritekid at gmail.com>
> Subject: Re: [meteorite-list] Meteorite Questions
> To: Meteorite-list <meteorite-list at meteoritecentral.com>


> 
> > For example, why does the rim of meteor crater appear "squared" in some
> > photos, while in others it appears very round?  Perspective?  Lighting?
> > Extremely highly localized tectonic shifting (back and forth)?
> 
> It has eroded into a somewhat rectangular shape over the 50,000 years
> that it's spent sitting there in the desert...it's current shape is
> probably due somewhat to stress fractures that exist either because
> they were created in the underlying rock by tectonic movement or
> possibly from the impact itself, so the angle of impact might have
> something to do with the orientation of the 'sides,' but you're
> dealing with advanced geology and physics there, in both of which I'm
> something of a dilettante.
> 


Charles O'Dale
President
RASC - Ottawa Centre
http://www.ottawa.rasc.ca/index.php
http://www.ottawa.rasc.ca/science/index.html