Nature · Earth Science
The great flatlands of the world
Plateaus are broad, raised areas of fairly flat land standing above their surroundings, while plains are low, level expanses. Between them they form the tablelands and open lowlands where much of the world's farming, grazing and population are concentrated.
Plateaus rise when broad blocks of crust are uplifted, when layers of lava pile up, or when erosion strips the softer land around a resistant cap. Plains form where rivers, seas, wind or ice deposit sediment over long periods, spreading it into wide, level surfaces.
A hard caprock protects the land below; as erosion eats in, a broad plateau shrinks to a flat-topped mesa and finally a slender butte.
Vast highlands lifted by the crust
When continents collide, huge slabs of crust are forced upward into high tablelands. The Tibetan Plateau, lifted by India ramming Asia, is the greatest example.
Flatlands built from ancient lava
Runny lava can flood across the land in eruption after eruption, layering basalt into a broad, flat plateau that later weathers into rich farmland.
Flat-topped remnants of eroded land
As erosion nibbles a plateau, a resistant caprock protects the land beneath it. The result shrinks from a wide mesa to a slender, tower-like butte.
Fertile lowlands built by rivers
Rivers in flood spread fine silt across their valleys, layer upon layer, building broad, fertile plains that have long been the breadbaskets of civilisation.