CompuServe Messages

<< I chose to speak of "roots" as the simplest way to refer to something getting pushed into the mantle as mountains were piled atop it and rebounding as the load was removed … It does make a difference in terms of what is rising and getting eroded – the wider-region uplift would accelerate erosion of things beyond the original mountain range's area, and offer less uplifting of the folds from the collision(s).>> I think I follow you here, yes. Look at the PreCambrian Shield and the sediments which were laid down, depressed and eroded by the Ice Ages, and which subsequently rebounded. The topography is concentric around the deepest "root" or deepest depression of the continental crust into the mantle, but it is the differential erosion of the individual layers still exposed around the dome of PreCambrian granites that provides the bulk of the topographic relief. Rebounding provides continually more opportunity for differential erosion to take place.