Plateaus form over millions of years. The highest, largest plateau in the world is the Tibetan Plateau in East Asia, which formed when two tectonic plates collided around 55 million years ago. Some plateaus result when magma inside the Earth rises toward the surface and pushes the flat, solid rock on the surface.
Plateaus exist on all continents across the globe and occupy up to one-third of the Earth's land. The two types of plateaus are dissected plateaus, which form when tectonic plates collide and produce upward motions in the Earth's crust, and volcanic plateaus, which result from accumulated lava flows due to repeated, minor volcanic eruptions.
Plateaus that result from constant lava streams form when lava oozes out of the Earth's surface through cracks and spread over large areas. Examples of plateaus that were created from lava flows include the Deccan Plateau in India and the Columbia Plateau in the U.S. Pacific Northwest. The Mascarene Plateau in the Indian Ocean spreads over a span of 770 square miles.
Some plateaus also form when wind and rain erode the side of an elevated area. An example of a plateau sculpted by the force of water is the Grand Canyon, which continuously changes shape due to the Colorado River.