AFAIK, an impact melt is created from the heat and energy of the collision itself. A contact metamorphism, in-situ. Whereas, a shock melt is created by the energy of the shock waves that travel through the rock and away from the impact site. The shock wave compression generates the heat. Reminds me of the great debate regarding Dhofar 026/461/ect. Whether it is an impact melt or not. First, it was said to be an impact melt breccia. Then others said it's actually a Shocked granulitic breccia. Then the ambiguous Crystalline melt classification. And now, the latest research puts it back as an Impact melt.. ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list