PPT Slide
Notes:
This illustration shows the gradients of portions of the the South Fork of the Eel River (California, USA) and the Maury River (Virginia, USA). Both of these rivers pass through gorges in resistant rock in which the gradient steepens appreciable (the reaches with arrows). Naïve expectation might suggest that the steep sections should be bedrock-floored, whereas bedrock in these channels is exposed primarily in the low gradient sections upstream and downstream from the canyons, and coarse, locally derived boulders mantle the bedrock in the steeper canyon sections.