Extrusive Landforms



A mountain is a landform that stands much higher than its surroundings. Mountains generally are larger and higher than hills. They generally have steep slopes and sharp or slightly rounded peaks or ridges. Mountains are created over long periods of time by tremendous forces in the earth. The earth scientists have come up with a theory that explains the formation of mountains. This theory is called plate tectonics.
Watch this video about the colliding of the continents and plate tectonics



The theory explains that the earth’s outer shell is made up of about 30 rigid plates of various sizes. The continents and the ocean basins make up the outer most part of these plates. The plates are in slow, continuous motion. Most mountain building occurs along boundaries between plates.

There are three basic kinds of mountains depending on the process by which they were formed.
  • volcanic mountain,
  • Fold Mountain, and
  • fault block mountain.
A block mountain is an uplifted block or upland which is bordered by faults on one side or more sides of the Rift Valley. The process of faulting forms a block mountain due to compressional forces.