Generally when large floods occur, thick’s layers of sediment settle in the effected area. This is not the case in the Grand Canyon which geologists have been able to inspect with great accuracy given that the inside of the rock walls can already be observed by the naked eye.
There is however a gemara that says that the consistency of the water in the mabul was thicker than the fluid of normal water and was also boiling. Could this explain why the geology of the Grand Canyon doesn’t at face appear to corroborate the chronology of the Torah? There are only fossils in certain layers of the rock, and different layers are comprised of sandstone or limestone. I’m not particularly knowledgeable with science and it doesn’t interest me very much, so I would love to see responses from anyone who has a more sophisticated understanding about this than I do.