Ch.6. Geomorphic Processes

Exogenic forces Endogenic Forces Geomorphic processes Originate on the earth surface- Weathering, Mass movement, erosion and deposition Endogenic Forces Originate below the surface- Orogenic, Epirogenic, Volcanism and earthquakes

Diastrophic forces Slow Movements Sudden forces These include two type of movements: Orogenic or mountain building force. Epirogenic or continent building forces Slow Movements Volcanism Earthquakes Sudden forces

Exogenic forces Weathering Mass wasting Erosion It includes breaking of rocks on its place. It does not involves any movement of eth weathered material. Mass wasting It include movement of earth material down the slope. It is caused by gravity Erosion It involves breaking, transporting and deposition of weathered material It s done by various agents like river, glacier, wind etc

Mechanical weathering Chemical Weathering Mechanical weathering Biological Weathering

Chemical weathering Carbonation-Carbonation is the mixing of water with carbon dioxide to make carbonic acid. Carbonation takes place when the rock minerals react with weak carbonic acid formed when water combines with carbon dioxide in the atmosphere. Carbonic acid acts on the rock by breaking down and dissolving its mineral contents. The dissolved materials are washed away by ground water, and the soluble ions are stored in the groundwater supply. Rocks such as limestone and feldspar experience this type of chemical weathering more. This type of weathering is important in the formation of caves. Solution- Removal of soluble minerals from the rock 3. Hydration-Hydration is the chemical reactions caused by water. Water reacts with the rock and alters the size and chemical compositions of the minerals. 4. Oxidation or Reduction- Reaction of atmospheric oxygen with minerals of the rock, eg, rusting of iron

Physical or Mechanical weathering Unloading : It results in exfoliation or onion weathering.

Freezing and Thawing and frost wedging

Expansion and Contraction

Salt Weathering

Biological Weathering

Mass movements

Land Slide

Earth Flow

Creep- Very slow movement

Slump

Rock Slide

Soil Profile