A plateau is a flat, elevated landform that rises sharply above the surrounding area on at least one side. Plateaus occur on every continent and take up a third of the Earths land. They are one of the four major landforms, along with mountains, plains, and hills.

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. The Colorado Plateau, in the western United States, has been rising about .03 centimeter (.01 inch) a year for more than 10 million years.

A volcanic plateau is formed by numerous small volcanic eruptions that slowly build up over time, forming a plateau from the resulting lava flows. The North Island Volcanic Plateau covers most of the central part of the North Island of New Zealand. This volcanic plateau still has three active volcanoes: Mount Tongariro, Mount Ngauruhoe, and Mount Ruapehu.

Erosion can influence the shape of a plateau. Soft rock often erodes away on the top of a plateau. Many plateaus are therefore topped with a hard, durable surface called caprock. Caprock protects the plateau from erosion of the soil underneath it.

Valleys form when river water cuts through the plateau. The Columbia Plateau, between the Cascade and Rocky mountains in the northwestern United States, is cut through by the Columbia River.

Erosion shapes plateaus in other ways. Sometimes, a plateau is so eroded that it is broken up into smaller raised sections called outliers. Many outlier plateaus are composed of very old, dense rock formations. Iron ore and coal often are found in plateau outliers.

The largest plateau in the world is the Tibetan Plateau, located in central Asia. It stretches through the countries of Tibet, China, and India and occupies an area of 2.5 million square kilometers (1.5 million square miles), which is four times the size of the U.S. state of Texas.

plateau
This cowboy gazes out from a small plateau in Monument Valley, Arizona, across an enormous plateau—the Colorado Plateau, which covers most of the American Southwest.

Oceanic Plateaus
Plateaus in the ocean are divided into two groups. One group is made of continental crust. The other is made of igneous rock. Igneous oceanic plateaus represent an age between the older, less-dense continental crust and the younger, more dense oceanic crust.

active volcano
Noun

volcano that has had a recorded eruption since the last glacial period, about 10,000 years ago.

caprock
Noun

strong, hard rock that remains on top of a mesa.

Noun

dark, solid fossil fuel mined from the earth.

Noun

one of the seven main land masses on Earth.

continental crust
Noun

thick layer of Earth that sits beneath continents.

dense
Adjective

having parts or molecules that are packed closely together.

dissected plateau
Noun

flat, elevated landform created by upward movement of the Earth's crust.

durable
Adjective

strong and long-lasting.

Noun

act in which earth is worn away, often by water, wind, or ice.

Noun

rock formed by the cooling of magma or lava.

iron
Noun

chemical element with the symbol Fe.

Noun

specific natural feature on the Earth's surface.

oceanic crust
Noun

thin layer of the Earth that sits beneath ocean basins.

oceanic plateau
Noun

flat, elevated landform rising from the ocean floor.

Noun

deposit in the Earth of minerals containing valuable metal.

outlier
Noun

part of a landform separated from the rest by erosion.

Noun

large region that is higher than the surrounding area and relatively flat.

Noun

large stream of flowing fresh water.

soft rock
Noun

solid mineral matter that is easily worn or broken.

tectonic plate
Noun

massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate.

Tibetan Plateau
Noun

flat, elevated landform located in Tibet, China, and India. Also known as the "rooftop of the world."

valley
Noun

depression in the Earth between hills.

volcanic plateau
Noun

flat, elevated landform created by layers of lava from volcanic eruptions.