Miami Limestone

The Miami Limestone (formerly the Miami Oolite) is a Pleistocene (see time scale) marine limestone. It occurs at or near the surface in southeastern peninsular Florida from Palm Beach County to Dade and Monroe Counties and in the keys from Big Pine Key to the Marquesas Keys. The Miami Limestone consists of two facies: an oolitic facies and a bryozoan facies. The oolitic facies consists of white to orangish gray, oolitic limestone with scattered concentrations of fossils. Ooliths are small rounded grains so named because they look like fish eggs. Ooliths are formed by the deposition of layers of calcite around tiny particles, such as sand grains or shell fragments. The bryozoan facies consists of white to orangish gray, sandy, fossiliferous limestone. Beds of quartz sand and limey sandstones may also be present. Fossils present include mollusks, bryozoans, and corals. An excellent exposure is observable at Alice Wainright Park, in Coral Gables, Dade County.