CompuServe Messages

>>>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.<<< Maybe — I must say that I'm more than a little sceptical. Sounds to me like adjusting the facts to fit the theory rather than developing the theory to fit the facts. There's a "hole" in the Appalachian chain between Southern New York and Quebec, and in that hole we see evidence of lots of uplift and erosion — e.g. 5 or 6 miles of sediment apparently eroded in the Upper Conneticut River Valley. On both sides we have these tidy folded mountains that are purported to have eroded only a little — only a few thousand feet of sediment missing — in 300,000,000 years. I don't have any problem with localized uplifts, but I have a lot of trouble with the selective erosion that seems to be necessary to make the model work. I'd suggest that the facts might point to the Appalachians being a much more recent structure than we can currently account for them being.