A plateau is a type of landform that is not limited to the desert.
Plateaus can best be described as tablelands or flat-topped mountains that are of a relatively uniform height. Their size can be quite vast or very small and overall they stand much taller than the land that surrounds them. Older plateaus are characterized by an eroded landscape and vegetation can range anywhere from barren to heavily forested.
Plateaus are present on every continent, including Antarctica and take up an estimated 45 percent of the earth’s land surface. By definition, a plateau must rise at least 1500 feet above the neighboring land areas.The highest and largest plateau on earth may be the Tibetan plateau in southwest China. Australia is also marked by a large plateau in the west, called the Western Plateau. Sometimes one large plateau can contain smaller tablelands located right on top of the central land mass, such as what occurs on the Colorado plateau of the western U.S.
In general, plateaus form from the geological changes to the earth’s surface that occur over millions of years. More specifically, these landforms might be either igneous or sedimentary in their formation. Igneous plateaus exhibit a surface layer of basalt, a very hard rock created through volcanic activity. On the other hand, large sandstone or other similar sedimentary rock plateaus are created when sedimentary rock formations on the ocean floor are uplifted to form a new land mass.
Once land is uplifted to form a plateau, there are several erosive forces that can change the terrain of the land mass. By far, the most important is water, which over long periods of time will flow across the landscape and create canyons along its path. When the base rock is sedimentary, the resulting erosive force can create a stunning landscape, as is the case of the Grand Canyon located in the Colorado Plateau. Wind erosion can also occur on a plateau, but its overall effect is much less when compared with water erosion.
Plate tectonics can also play an important role in creating a large raised land mass, such as a plateau. Current geological theory suggests that the earth consists of eight large plates and several smaller ones. When two plates converge and collide the result may be major uplifting of land. When this type of geological event occurs the results manifest themselves in the terms of millions of years. These results often create large mountain ranges and high plateaus, such as the Tibetan Plateau in China.