The Ocala Limestone consists of white to cream, Upper Eocene marine limestones and occasional dolostones. Generally the Ocala Limestone is soft and porous, but in places it is hard and dense because of cementation of the particles by crystalline calcite. The deposit is remarkable in that it is composed of almost pure calcium carbonate: shells of sea creatures and very tiny chalky particles. Ocala Limestone underlies almost all of Florida, but it is found at the surface of the land only in a small portion of the state. It is mined for use as roadbase and cement where it is close to the surface in west-central Florida and the northwestern peninsula. Fossils present in the Ocala Limestone include abundant large and smaller foraminifers, echinoids, bryozoans, mollusks and rare vertebrates.