--- On Fri, 1/9/09, Michael Gilmer <[email protected]> wrote: > BTW, shouldn't the Gobi be a good source of meteorites?
The Gobi has become a very researched area in the last 2 decades for its dinosaur fossil deposits. We would hope that given the amount of dinosaur hunting , it would also yield a meteorite or two but I haven't heard of any finds being reported. Then again I've not researched specifically, perhaps there are more than I am aware of. I have read --but can't confirm where-- that the Gobi is not a producer of meteorites because: 1.AGE: While parts of the Gobi date back to 20-30 my, by in large, the Gobi we know today isn't so old - its youngish undisturbed "apron" for collecting hasn't been lain out open to receive the heavenly fruits as long as the Sahara's has been. It certainly has an older core but human induced desertification is responsible for making it the 4th largest desert. The Gobi lies in the rain shadow of the somewhat young Himalayans--it is getting dryer over time. One would need to look at its paleoclimate since the last ice retreat for comparison to the Sahara's climate and expansion to spot the differences. The Gobi plunges to -40 degrees in winter so the thaw freeze cycle is more a weathering factor there than in the Sahara. Both have grown under human occupation, so if any stash of meteorites are to be found we should be looking in the oldest regions--except for the next caveat. 2.SAND vs. ROCK cover. Gobi Bedrock Geology is more exposed than in North Africa. The existing sand dunes in the Gobi are semi-rare in the Gobi as compared to the Sahara. We know that the migration of sand dunes has a preserving effect on Saharan meteorites buffering them from extremes. The dunes of the Gobi are more localized in basins like those of Colorado for example. Elton ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
