The grand canyon was cut while it was still wet, and probably in a week or two.
The lowest portion of the canyon demonstrates how it would have been cut if it had been cut after drying out.
Creationists teach that a gigantic surge of water carved out the Grand Canyon, in a short period of time, from a vast mud deposit which subsequently hardened into layers of stone. This argument does not hold up because:
(1) The Grand Canyon is immense; it is inconceivable that all that material could be removed in a short period of time.
(2) Recently exposed mud deposits have essentially no vertical stability; a trench more than 5 feet deep must be shored to keep it from collapsing. The Grand Canyon is a mile deep and has vertical walls of over a thousand feet in height.
(3) The Grand Canyon formation is cut down into an almost horizontal plateau. How could a surge of water on a horizontal surface attain the velocity to remove all that material? Answer: it could not; it would simply spread out over the plateau.
(4) There is no way that a huge deposit of mud could be transformed into the existing system of dozens of different kinds of rock strata extending in a consistent sequence over hundreds of square miles.
http://www.chem.tufts.edu/science/FrankSteiger/flood.htm
#4 is important in that if the Grand Canyon was “cut while it was still wet (mud deposited by Noah’s Flood?), and probably in a week or two”, you wouldn’t expect to see the many different types of rock strata and you also can’t explain why some types of animal and plant fossilization, long extinct are found in lower strata and not in the higher and why some types of animal and plant fossilization of more recent life is not found in the lower strata if all this took place over the course of a week or two.