There are two kinds of plateaus: dissected plateaus and volcanic plateaus.
A dissected plateau forms as a result of upward movement in the Earths crust. The uplift is caused by the slow collision of tectonic plates.
Through the continental process of weathering and erosion by running water, ice and winds, high and extensive plateaus are gradually worn down and their surfaces made irregular in the humid highlands stream action and sometimes glaciers cuts deep narrow valleys in the plateau and are also called dissected plateaus. An example of dissected plateaus is Scottish Highlands.
In drier countries, vertical corrosion by rivers and abrasion by winds dissect the plateaus into steep sided tabular masses termed mesas and butters intersected by deep canyons. This is a common feature of arid and semi-arid areas.
These kinds of plateaus are formed by molten lava. When molten lava erupts from the earth’s crust, it spreads onto its surface to form successive sheets of basaltic lava. These solidify to form the lava plateau.
Some of the well-known lava plateaus include the Antrim plateau of Northern Ireland and the North Western Plateau of the Deccan Plateau.
The most remarkable plateau built by lava is the Columbia-Snake Plateau, which covers an area almost twice as big as Malaysia. Each layer of the lava flow is 100 feet thick and the entire depth of such successive lava layers is estimated to be almost a mile.