The early oceanic sediments are covered by desert deposits of the Prairie Evaporite, Interlake, and Minnelusa formations. Oncolites found in the Interlake prove that these deposits took some time to be deposited. Half of these salt beds are up to 200 feet thick. Since they are sandwiched between other sediments, to explain them on the basis of a global, one-year flood, requires a mechanism by which undersaturated sea water can dump its salt. If the sea were super-saturated during the flood, the no fish would have survived.
Evaporation is the only reasonable explanation.
Third, the geologic column is not divided by hydrodynamic sorting. That is on top of the beds of marine vertebrates would be found amphibians, then reptiles and finally birds and mammals. The biggest single factor for how fast an object settles in a fluid is the size. The relevant physical law is Stoke's Law. The larger an object, the faster it falls.