Hello all - Most entertaining to read the National Geographic piece on Rio Cuarto. Here I was wondering how to tackle the incredible work load that I am already facing, and now I find my schedule for the next week or so pretty much determined for me.
Among the many other fascinating things which I read in the National Geographic summary, I was quite amazed to learn from these folks that there was only one oblique impact which occured in our Solar System, and that its remains were found on the Moon. Now if I am not mistaken, there are many long straight valleys which have been have been observed on Mars. Hell, I know I am not mistaken, I attended one of the annual Mars lectures up at the National Academy of Sciences several years back and was shown them for 45 minutes or so. If anyone here has any mechanism for the creation of these very linear features on Mars other than oblique impact with the heat of the entry setting of clathrate reactions, I sure would like to hear about it. Detailed comment is going to have to wait getting to a library to read the Science article, but my first estimate from the synopsis is that what has happened is that some folks have confused themselves pretty well and are now going on to share their confusion with the general public. Are there other linear features on the Pampas? Yes - but remembering Schultz's original article, he found glass in the crater rim, not isolated as tektites. Was there an earlier impact in the area which formed tektites? Clearly yes, but IF the dating of these tektites is correct then they resulted from an impact separate from the Rio Cuarto impact. The orientation of the other craters is also of interest, as they may reflect not dune activity but the impact of other fragments of a single oblique impactor. Contrary to the summary, Schultz found no meteorites, but instead found the miniscule particles left after impact. Unless the meteorites found in the craters agree with the particles, then they represent entirely different later meteorite falls. Given the volumes of Native American material which refer to a major impact event, if Rio Cuarto turns out not to be the site of that impact, then a major effort will have to be made to find out where the thing did hit. It strikes me that the easiest way to determine whether or not Rio Cuarto was the site of that impact would be through excavations peripheral ot the area looking for the burn level, which should be datable by C14 ep __________________________________________________ Do You Yahoo!? LAUNCH - Your Yahoo! Music Experience http://launch.yahoo.com ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
