There is a type of breccia called "impact breccia." For a better explanation than I can give, see the following Wiki article on the Alamo bolide impact in Nevada:
http://en.wikipedia.org/wiki/Alamo_bolide_impact or, better yet, Google "impact breccia." Louise From: [email protected] List-Post: [email protected] Date: Wed, 27 Jan 2010 09:42:29 -0500 To: [email protected] Subject: [Texascavers] breccia Mystery rocks? Alien footprints? Pardon me, but it looks like plain old breccia to me. See: http://geology.about.com/od/rocks/ig/sedrockindex/rocpicbreccia.htm Louise No question about it being breccia, I just want to know how it happened. How could such a cake mix slurry of broken chunks get embedded in conventional limestone then get spread in a thin flat layer across a wide area? The relative hardness could well be an unrelated issue. Sleazel
