Hello, I've just got some cute little NWA 788 from Jim Strope (thanks Jim!) and noted they are brecciated. This got me wondering about how the process of brecciation occurred in the parent body and I realised that I didn't know. So, can I assume that the meteorite, prior to ejection from the parent asteroid was already a brecciated rock lying on the surface or embedded in the lithosphere, or does brecciation occur when the regolith is pounded by an impact, fusing together all the different rocks lying around on the surface of the planetoid? I would have thought that if brecciated meteorites were formed by fusing together the different lithologies lying about on the parent body at the time of impact, then shock melts would be very apparent - I am not aware that this is the case in the vast majority of brecciated meteorites therefore implying that the brecciation I see was already in the parent rock prior to ejection. If that is the case, how did the different lithologies get compressed together in the first place? I didn;t think that there would have been enough gravitational attraction on a 'typical' parent body to have enabled the processed that would allow the asteroid to be able to create this sort of metamorphosed (ie brecciated) rock. Please forgive my obvious "geology 101" type question, but I am, after all, starting a geology degree so need all the help I can get! I know squat all but I need to learn!!!!
very best and await your wisdom to illuminate my intellectual darkness! -- In gentle decay, dave http://www.meteorites.ic24.net/index.html http://www.thc.u-net.com/davethc1.htm "I have a proof that x^n+y^n=z^n never has integer solutions for n>2. However, it won't fit into my signature file...." ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
