Fines (and microfossils of the same mass) can drop out of high energy water
if the water is supersaturated with that particular size and weight of
particle. As a wave propagates and spreads out, it looses energy. As the
energy level drops, supersaturation can be reached for portions of the load
it is carrying and those particles will be dropped.
> ME: This scenario also runs into trouble with regard to preservation of
> delicate structures such as whole skeletons, soft parts, footprints, etc.
As tsunamis spread out from the source and sweep inland they will loose
energy to the point where the wave will stop and then begin to drain off.
At the lower energy levels articulated skeletons and soft body parts can be
more gently burried. In some places, as the waters drain off the newly
deposited layers, some animals that have thus far survived the catastrophe
could leave footprints. To be preserved, another wave (at its lower energy
state) must sweep in and cover the prints with another layer of mud/sand.