About 55% surface of the earth is covered by Plains.
The deposition of sediments by rivers has formed most of the plains.
In addition to rivers, many plains were also formed by wind, ice, and tectonic activity.
The average height of plains is less than 200 meters.
Structural plains are mainly formed by the uplift of a part of the sea-floor or continental shelf.
These are located on the borders of almost all the major continents.
The south-eastern plain of the United States formed by the uplift of a part of the Gulf of Mexico is an example of this type of plain.
The subsidence of areas causes the formation of the structural plains. For example, the central low-lands of Australia
Erosional Plains are formed by the continuous and a long-time erosion of all sorts of upland.
The surface of such plains is hardly smooth.
These are therefore also called peneplains which mean almost a plain.
Examples of Erosional Plains are the Canadian shield and the West Siberian plain.
Depositional landforms are formed by the Fragments of soil, regolith, and bedrock that are removed from the parent rock and deposited somewhere else.
Riverine or alluvial plains are formed by river deposits.
Some examples of alluvial plains are:
- The Indo Gangetic plain ( Indian sub-continent)
- The Ganga-Brahmaputra Delta Plain ( Bangladesh)
- The Lombardy Plain of the Po River ( Italy)
- The Hwang-Ho Plain ( North China)
Lacustrine plain or a lake plain are formed by the deposition of sediments in a lake.
The Valley of Kashmir and that of Manipur are examples of the two most prominent lacustrine plains in India.
Glacial or drift plains are formed by glacial deposits.
The examples of glacial plains are Plains of Canada and North-Western Europe.
When the wind is the major agent of deposition, they are called loess plains.
The deposits of loessair-borne fine dust particles have created loess plains of North-West China.