Coastal Plain Physiography, Regional Setting, Part 2
Coastal Plain and Continental Shelf
• Coastal Plain and the continental shelf are names for the different parts of the same surface along the edge of the continent.
The Coastal Plain and the continental shelf are part of a continuous surface formed on the top of a thick pile of sediment deposited along the edge of the continent. The difference between them is that the Coastal Plain is above water and the continental shelf is below sea level.
• Coastal Plain is emergent, whereas the continental shelf is submergent.
• The widths of the Coastal Plain and continental shelf change over geologic time as sea level rises and falls.
• In the latest Ice Age (Pleistocene), sea level was hundreds of feet lower; therefore, the Coastal Plain was much broader and the continental shelf much narrower.