A plateau is an extensive region of flat land that is higher in elevation than its surrounding area. Plateaus often have steep slopes on one or more sides or may be partially surrounded by mountains. Examples of notable plateaus include the Altiplano, which is located in the southern part of Peru and western region of Bolivia, within the Andrea Mountains, and the Colorado Plateau, which contains the Grand Canyon that was carved by the Colorado River. Other plateaus, such as the Deccan Plateau in the central part of India, are not located near any mountain ranges. Different types of plateaus can be categorized based on the type of geological processes that caused their formation. There are four primary plateau classifications: intermontane, volcanic, piedmont, and continental.
Intermontane plateaus are the highest in the world, and typically border mountainous terrain. In most cases, they are surrounded or enclosed by mountain ranges. Examples of intermontane plateaus include the Tibetan Plateau and the Mongolian Plateau, both of which are located in Asia. The southern part of the Tibetan Plateau is surrounded by the Himalayas, while the Kunlun Mountains are situated to the north. Similarly, the Mongolian Plateau is surrounded by several mountains such as the Nan Mountains, Hentiyn Mountains, and Sayan Mountains.
Example: Tibetan Plateau
The Tibetan Plateau, also known as the Himalayan Plateau, is a large plateau located in both East and Central Asia, spanning regions such as the Tibetan Autonomous Region, Qinghai Province in Northwestern China, and parts of India including Jammu and Kashmir and Himachal Pradesh. The Tibetan Plateau covers an area of 970,000 sq mi and stretches for 620 mi from north to south, and 1,600 mi from east to west. The average elevation of the Tibetan Plateau is slightly more than 14,800 ft, making it the world’s highest plateau. It is often referred to as the "Roof of the World" due to its location at roughly 3 miles above sea level. The Tibetan Plateau is bounded by exceptionally high mountain ranges, which are home to the two highest summits in the world, Everest and K2.
Volcanic plateaus are formed as a result of volcanic activity, and are common in areas of widespread volcanic eruptions. Magma that escapes from the Earth's crust through fissures or narrow cracks reaches the surface and spreads over a large area, and later solidifies to form a plateau. These types of plateaus are typically made up of layers of lava sheets. There are two types of volcanic plateaus: lava plateaus and pyroclastic plateaus.
a. Lava Plateau
Lava plateaus are formed as a result of highly fluid basaltic lava that flows through vents after numerous eruptions. Additionally, lava plateaus that are formed when volcanic eruptions are not violent, which are referred to as quiet eruptions. These eruptions occur as a result of the low viscosity of lava, which is highly fluid and contains small amounts of trapped gases. The flow of the lava sheet is extruded from linear rifts, fissures, or gigantic volcanic eruptions through numerous events that characterize the prehistoric period of giant flood basalts. Several successive lava flows may cover the original landscape and finally form a plateau, which contains cedar cones, lava fields, shield volcanoes, or other landforms associated with volcanic activity. In some instances, a lava plateau could be part of a single volcano. It is believed that the largest and most extensive basaltic plateaus occurred during the Paleogene era, and could have covered an area of more than 690,000 sq mi in the northern part of the Atlantic Ocean. This region, popularly known as the Thulean Plateau, was broken up by the foundering of the Earth's crust, and resulted in the formation of the present ocean basin.
b. Pyroclastic Plateau
Pyroclastic plateaus, also known as ignimbrite plateaus, are formed as a result of large pyroclastic flows, and are typically layers of pyroclastic, such as volcanic ash, tephra, and agglomerate that have been cemented into felsic, mafic, or tuffs. Examples of pyroclastic plateaus include the North Island Volcanic Plateau in New Zealand and the Shirasu-Daichi Plateau, which covers the southern part of Kyushu, Japan.
Piedmont plateaus are plateaus that border a mountain on one side and a plain or ocean on the side. The term piedmont is borrowed from two French words, pied meaning "foot" and mont meaning "mountain." Taken together, piedmont translates to "foot of a mountain." Examples of piedmont plateaus include the Piedmont Plateau, which is located in the eastern United States, between the Appalachian Mountains and the Atlantic Coastal Plain, and the Patagonian Plateau, which is located in South America and covers parts of Chile and Argentina.
Continental plateaus are plateaus that are bordered by plains or oceans on all sides. Therefore, these plateaus formed away from the mountains. Examples of continental plateaus include the Antarctic Plateau (East Antarctica), Chota Nagpur Plateau (India), and Deccan Plateau (India).
Submarine or oceanic plateaus are large and relatively flat elevations on the ocean floor that are higher than the surrounding area. There are currently 184 identified oceanic plateaus, which cover a combined area of about 7.2 million sq mi, or approximately 5.11% of the Earth’s oceans. The Pacific Ocean, particularly in the region near New Zealand and Australia, has a large number of oceanic plateaus. Volcanic islands, mantle plumes, and hotspots are associated with the formation of oceanic plateaus. Some of the largest oceanic plateaus include the Caribbean, Mid-Pacific Mountains, and Ontong Java, which are located on thermal swells. Some oceanic plateaus are made of rifted continental crust, such as the Lord Howe Rise, Falkland Plateau, and parts of Seychelles, Kerguelen, and Arctic ridges.