#16 I do not see a canyon but a raised surface in 3d with a squiggly river on top.
Satellite images, as well as pictures taken by astronauts in orbit, seem to indicate that the Grand Canyon is an enormous Lichtenberg figure, in other words, a gigantic lightning scar. As the Electric Universe hypothesis suggests, electric discharge machining (EDM) might account for the Canyon’s appearance: steep walls, thousands of layers, brachiated side canyons at practically every scale, and periodic, hemispherical “nips” cut into each rim.
http://www.ifiseeu.com/geophysics/grand-canyon-1.htm