Thus, the dinosaurs likely died out gradually in the post-flood period. This is also consistent with the occassional reports through history of people having seen dinosaurs. It is important to understand certain terms from geology. Sedimentary rock is rock that has formed from some kind of sediment. In many cases it is mud or sand that has fallen out of water and then hardened to rock.
Some sedimentary rock can also form from chemical and biological processes.
Calcium and Carbon Dioxide can combine in water to form solid Calcium Carbonate, so this can produce the rock known as limestone. Limestone forms under water but is not related to flowing water or water carrying sediment particles. Igneous rock is basically volcanic in origin. It does not involve particles falling or precipitating out of water but rather comes out of the Earth, from the mantle of the Earth. Metamorphic rock refers to a variety of types of rock that has come from altering other rock or other materials in various ways.