Atlantic Coastal Plain
Quick Summary
The Atlantic Coastal Plain is a nearly flat, often swampy region stretching from Cape Cod, Massachusetts, to beyond the Mexican border. It is part of the continental platform, characterized by young, poorly consolidated sediments. This plain extends underwater as the continental shelf.1
The plain's gentle slope means minor land shifts can significantly alter coastlines. Florida is an example of an uplifted area, with much of its land less than 10 feet above sea level and prone to flooding and storms. Conversely, glacial ice depressed parts of the plain north of New York City, submerging it beneath the sea, leaving behind remnants like Cape Cod and Long Island.1
While soils are generally poor, some areas support agriculture, such as Florida's citrus regions and the historical Cotton Belt. The Atlantic Plain is also a significant source of petroleum and natural gas, particularly along the Gulf Coast.1
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MarylandDrainage and soilsTo the south the Coastal Plain is sandy; to the north it is loamy and fertile. Its water edges—consisting of salt marshes, or wetlands—exasperate mapmakers as erosion periodically fills in a swamp or deletes an entire island: St. Clements Island (also called Blakiston Island), for example, is about one-tenth…
Read MoreTo the south the Coastal Plain is sandy; to the north it is loamy and fertile. Its water edges—consisting of salt marshes, or wetlands—exasperate mapmakers as erosion periodically fills in a swamp or deletes an entire island: St. Clements Island (also called Blakiston Island), for example, is about one-tenth…
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South CarolinaReliefThe Coastal Plain province comprises the southern and eastern thirds of the state, and its elevation varies from sea level to about 300 feet (90 meters). The region is slightly rolling near the midlands and flat toward the coast. Its 187-mile (300-km) coastline consists of the…
Read MoreThe Coastal Plain province comprises the southern and eastern thirds of the state, and its elevation varies from sea level to about 300 feet (90 meters). The region is slightly rolling near the midlands and flat toward the coast. Its 187-mile (300-km) coastline consists of the…
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United StatesThe Atlantic PlainThe eastern and southeastern fringes of the United States are part of the outermost margins of the continental platform, repeatedly invaded by the sea and veneered with layer after layer of young, poorly consolidated sediments. Part of this platform now lies slightly above…
Read MoreThe eastern and southeastern fringes of the United States are part of the outermost margins of the continental platform, repeatedly invaded by the sea and veneered with layer after layer of young, poorly consolidated sediments. Part of this platform now lies slightly above…
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