You should read through your own post and see how absurd and unrealistic each of your assertions is.
Having considerable experience with water running over recently placed earth embankments, it is obvious that they are a perfect microcosm of the creation of the Grand Canyon. The size of the area is irrelevent, since the amount of water was proportional. The “hardening into stone” is the same issue the world over, and is due to the fact that all of the deposited material was dissolved in hot water loaded with carbonates, the world over, and by cooling and drying it would inevitably become some form of calcareous stone.
Water gushing over a sedimentary plateau does not simply spread out. It never does. It quickly cuts numerous gouges in completely random fashion, just like the Grand Canyon. There really is no other way it could have formed. Were it already solidified, it would be nothing but deep, narrow gouges, like the gouge cut into the bottom of the Grand canyon, long after it had solidified.
At Mount Saint Helens there is a miniature “Grand Canyon”. It was cut in a short period from the melting snow.
It size is supendous, maybe a third of Grand Canyon.
“...
An explosive eruption of Mount St. Helens on March 19, 1982, melted a thick snowpack in the crater creating a destructive sheetlike flood and mudflow which downcut the rockslide and pyroclastic flow deposits north of the volcano. The largest steam explosion pit (shown in Figure 3 as it was previous to March 19) overflowed its west rim and cut a deep ravine into the 1980 pumice deposits to the west (Waitt et al. 1983). The flow formed anastomosing channels over much of the hummocky rockslide debris allowing cataracts to erode headward and established for the first time since 1980 a dendritic integration of the North Fork Toutle drainage. Erosion has occurred intermittently with most of the established drainage lines being formed in March 1982....”
appreciate your points
Thanks