I think that any crater in loose sediments would likely be filled in rapidly by the same mechanisms that deposited the sediment in the first place. You might, for a while, be able to track the crater by deformation in the surrounding sedimentary layers, but eventually it would all even out, leaving barely a ruffle in the geologic record. Only craters in hard, non-disappearing rock, not sludgy mud, would have a chance of remaining long enough for us to discover them.
Tracy Latimer ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list