How are structural plains formed?

Structural plains: These are the extensive lowlands of the earth bordering all the

continents.

These plains are mainly formed by the up liftment of a part of the sea-floor or

continental shelf. The south eastern plains of the United States formed by the

up liftment of a part of the Gulf of Mexico are an example of this type of plains.

The structural plains may also be formed by the subsidence of areas. One such

example is the central low-lands of Australia.