Geomorphic Processes

Geomorphic processes are natural mechanisms that modify the Earth's surface. These include both internal (endogenic) and external (exogenic) processes, shaping landforms through movements like earthquakes, volcanic activity, weathering, erosion, and deposition.

Endogenic Processes

Diastrophism

This refers to deformation of the Earth's crust due to tectonic forces. It includes:

Orogenic Movements – Mountain building (e.g., Himalayas).
Epeirogenic Movements – Vertical movements of land (e.g., plateau uplift).
Faulting and Folding – Results in structural deformation of rocks.

Volcanism

It involves the movement of molten magma from the Earth's interior to the surface, forming volcanic landforms. It may be:

Intrusive – Magma cools below the surface.
Extrusive – Lava reaches the surface (e.g., volcanoes).

Exogenic Processes

These are external forces originating from the atmosphere, hydrosphere, and biosphere. They include weathering, mass movements, erosion, and deposition.

Weathering

Chemical Weathering Processes

Oxidation – Reaction with oxygen (e.g., rusting of iron).
Carbonation – Reaction with carbonic acid, forming limestone caves.
Hydration – Water absorption alters mineral structure.
Solution – Soluble minerals dissolve in water.

Physical Weathering Processes

Frost Action – Water freezes in cracks, expanding them.
Exfoliation – Peeling off outer rock layers due to temperature variation.
Granular Disintegration – Breakdown due to differential heating.

Biological Activity And Weathering

Plants, animals, and microbes break down rocks by physical and chemical means, such as root growth or lichen activity.

Special Effects Of Weathering

Examples include formation of karst landscapes (limestone regions), tors, and soil profiles.

Significance Of Weathering

Forms soil for agriculture.
Contributes to landform development.
Helps in nutrient cycling.

Mass Movements

Landslides

These are sudden downward movements of rock and soil under the influence of gravity. They are common in hilly terrains and are influenced by slope, water, vegetation, and human activities.

Erosion And Deposition

Erosion is the wearing away and transportation of surface materials by agents like water, wind, glaciers, and waves. Deposition is the laying down of this material, creating landforms such as deltas, sand dunes, moraines, and beaches.

Soil Formation

Process Of Soil Formation

Soil forms through the weathering of rocks and the accumulation of organic matter. It involves:

Disintegration of rocks
Accumulation of humus
Mixing and transformation

Soil-Forming Factors

There are five main factors:

Parent Material

The mineral and organic material from which soil forms.

Topography

Land slope and elevation affect drainage and erosion, influencing soil depth and texture.

Climate

Rainfall and temperature affect weathering rates and organic matter accumulation.

Biological Activity

Organisms like earthworms, insects, fungi, and plants contribute to soil mixing and nutrient cycling.

Time

Soil development is a slow process and depends on the time over which other factors act.