Geomorphic Process

The internal and external forces causing stresses and chemical action on earth materials and bringing about changes in the configuration of the surface of the earth.

Exogenic Forces

The forces which derive their strength from the earth’s exterior or originate within the earth’s atmosphere.

The action of exogenic forces results in wearing down and hence they are considered as land wearing forces.

Types

1.Weathering

2.Mass wasting

3.Erosion

4.Deposition

Weathering

Weathering is simply the chemical and/or physical breakdown of a rock material–weathering involves specific processes acting on rock materials at or near the surface of the Earth

Physical Weathering (mechanical)

Takes place when rock is split or broken into smaller pieces of the same material without changing its composition.

Example:  Breaking of a rock cliff into boulders and pebbles

Chemical (decomposition)

Takes place when the rock’s minerals are changed into different substances. uWater and water vapor are important agents of chemical weathering.

Example:  Formation of clay minerals from feldspar

Erosion

The physical removal and transportation of weathered material by water, wind, ice, or gravity. u

Types of Erosion

1.Fluvial

2.Aeolian

3.Ice: Glacial and Periglacial

4.Gravity

Mass Wasting

Also known as slope movement or mass movement

The transfer or movement of rock or soil down slope primarily by gravity. Mass wasting is a rapid form of erosion that works primarily under the influence of gravity in combination with other erosional agents.

Mass wasting occurs very quickly and can result in either small or large scale changes to the landscape depending on the type of event.

Factors that control mass wasting:

1.Steepness of slope

2.Water content of materials

3.Presence (or absence) of native vegetation

4.Human activities

Types of Mass Wasting

1.Rocks Falls

2.Landslides

3.Debris and Mudflows

4.Slump

5.Creep

Deposition

The process by which weathered and eroded materials are laid down or placed in a location that is different from their source.