CompuServe Messages

Doug >>From the river's viewpoint the towers-to-be are at the side of the canyon. But if you draw lines parallel to the _general_ trend of the river tangent to the meanders, you see a future canyon in which the towers are on the opposite side of the centerline from their "side" as now seen by the river. If a boat in the river sees a tower pass on starboard, a crow flying downstream along the centerline of the whole shebang will see it on the port side.<< No doubt this can occur. The cutting process would have effected the curves much more making them progressively wider than the straight sections and in deep canyons this is no the case. I haven't seen the San Juan Gooseneck, sounds very interesting and may be cutting but I still doubt cutting as the cause of vertical wall canyons. This does not take anything away from the traditional geological erosion process as a workable planet forming process, I just think earth had a different history. >>Low spots can be quite asymmetric. Let a general downtrend meet an anticline, fault, or whatever…<< True but there should be small side canyons on both sides or there would be a different set of layers on each side of the canyon which i believe isn't the case. >>The more cohesive the rock, the steeper its angle of repose, which I think is the main determinant of the classical V-shape of a river-cut valley. But where other tricks come into play like undercutting, less stable configurations steeper than the angle of repose may be found.<< Again this same process will widen the curves of a river if it was cutting a canyon. The curves in many canyons have the same parallel features on both sides, more or less. The curves are not wider than the straight sections. Vertical wall canyons a classic being the Rio Grande north of Albuquerque is where the fault creating the path for a river comes totally into focus. Have you seen it? Kamron