When Noah’s Flood ended (see Page titled Natural Selection by Noah’s Flood), some of the water which slid off the continents pooled, for instance two huge pools upstream from where today is the wondrous Grand Canyon, the huge pools called lakes Hopi and Grand, respectively the size of Lake Michigan and Lake Huron, which by tectonism or just erosion broke through to gouge out the Grand Canyon, rapidly cut through sedimentary layers which had yet to lithify, soon after the Flood.