Hmmm. Igneous rock underneath, devoid of fossils, then layers upon layers of sandstone and metamorphic rock containing bazillions of mixed fossils, now, what forces on earth could have brought about such a cataclysmic chafe, all of a sudden like?
Hmmm. Water. Flood, laminar deposition, channular erosion of massive amounts of sediments....
World wide flood?
Nah. That fits another paradigm and we reject the basic premise of that one, but replace it easily with untold, unobserved eons of time.
Bingo we have a winner
There aren’t any fossils in most metamorphic rocks. Maybe in a marble, which is metamorphosed limestone.
The grand canyon was formed by a stream of water flowing uphill for billions of years.
Don’t you have a science book?