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" <[EMAIL PROTECTED]> > Subject: Re: [meteorite-list] Meteorite Questions > To: Meteorite-list <meteorite-list@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 ______________________________________________ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
