Atlantic Coastal Plain
The Atlantic Coastal Plain stretches from Long Island to southern New Jersey and includes parts of Staten Island. The plain, which slopes gently toward the sea, consists of loose sediment formations that date from the Cretaceous, Tertiary, and Quaternary time periods. This coastal plain is also big enough to be divided into three separate parts; the Inner Lowland (the low, broad valley that makes up the Delaware River Estuary, the Outer Lowland (along the southern New Jersey shoreline) and the Central Upland.
Eastern Florida Coastal Lowlands
The coastal lowlands on the east side of Florida have a similar shape as the ones near New York, but the heavier sediments are submerged in a shallow continental shelf that has been exposed by the sea level subsiding. Coastal tides and moving water are actively developing and maintaining coastal features such as beaches, swamps and mud flats. The sedimentary layers are a mixture of silt, sand and clay.
Coastal Plains of Florida and the Gulf of Mexico
These coastal plains are located on the western coast of Florida and the northern Gulf of Mexico. They were formed in the same way as the eastern coastal lowlands and are also made up of both irregular and smooth plains and open hills. The rocks and sediment date from the Mesozoic and Cenozoic Era, and include a mix of sand, clay and thin layers of fossilized sand and shells.
Louisiana Coast Prairies and Marshes
Moving further west along the Gulf of Mexico and into the southern states, we come to the prairies, beaches and marshes that form the broad lowlands and coastal plains of Louisiana. This not only includes coastal waters but a variety of both freshwater and saltwater streams and rivers. The vegetation in these areas consists of sedges, rushes, saltgrass and cordgrass.