A flood does not fit with the presence of marine fossils on the side of mountains for the following reasons:
1. Floods will erode mountains and the soil on them and deposit their sediments in the valleys.
2. The marine fossils are in the same positions as they lived, not scattered all over as if they were redeposited by a flood. This was observed in the sixteenth century by Leonardo da Vinci.
3. Fossilized tracks and burrows of marine organisms, show that the region was once under the sea. Seashells are not found in sediments that were not formerly covered by sea.
4. Shells do not float. So a flood would not wash them up onto a mountain regardless if an additional body of water covered the oceans.