CompuServe Messages

Don, >> All of what you said seems reasonable to me except the erosion of the Applachians. The modern Applachian chain is very clearly a folded structure. << True, it is. All I know is that three different texts in my library agree that the modern Appalachians are the roots of the ancient mountain ranges, mildly uplifted in the Cenozoic by isostatic adjustment and/or epeirogeny. Once uplifted, they started eroding again, revealing the synclines and anticlines that were all that was left of the ancient ranges. As soft layers eroded and harder layers resisted, the landscape formed into huge synclines, anticlines, and ridges up to hundreds of kilometers long, plunging at one end or the other. The entire Appalachian chain, from Maine to Georgia, is like that. Jon W.