CompuServe Messages

Hi, Ed– 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; I am not fussy about whether it is some inverted image of the mountains or a general bowing of the crust over a wider region. 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). –Doug