Bob Verish writes: > I have described it as being a loose rubble pile of > L6, L5, and L4 meteoroids; held together by the most > minimum of gravitational attraction. How else can you > explain a strewn field of stony meteorites with such a > variation in metamorphic grade, yet NO EVIDENCE of > brecciation, meaning that each individual stone is > either all L6, or all L5, or all L4, but never a > combination of the three?
I am not so sure if this is a strong indication that the Gold Basin meteorid was a rubble pile. If a rubble pile meteorid closes in on Earth, it will probably be disrupted by tidal forces *before* it enters the atmosphere. Maybe you would get a strewfield very similar to a strewfield produced by a compact meteorid that breaks up at in the atmosphere. Or maybe not, and the strewfield would be different (i.e., larger strewfield, no aerdynamic sorting of the meteorites by size, etc.). I don't know... On the other hand, the real border between a L5 and a L4 or L6 might be more blurry than the descriptions in the textbooks suggest. There is an interesting paper on the Dar al Gani region in the August 2002 issue of MAPS. The authors conclude that pairing based on class, shock level and weathering grade is problematic, because individual speciemns from ordinary chondrite strewfields were assigned to different classes. Either this is another strong indication for frequent rubble pile meteorids, or maybe we just see the fuzzy borders between petrographic types of meteorites. Who knows? I certainly don't... ;^) Best greetings, Herbert ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
