Notes

Force applied per unit area is called stress
Orogepy: It is a mountain building process
Epeirogeny: It is continental building process.
Debris Slide: Rapid rolling or sliding of earth debris without backward rotation of mass is known as debris slide.
Erosion: The erosion can be defined as “application of the kinetic energy associated with the agent to the surface of the land along which it moves”.
By deposition depressions get filled up.
Earth Flow: Movement of water-saturated clayey or silty earth materials down low-angle terraces or hillsides is known as earth flow.
Nitrogen Fixation: Bacteria and other soil organisms take gaseous nitrogen from the air and convert it into a chemical form that can be used by plants. This process is known as nitrogen fixation.
Desilication: Removal of silica from the soil is known as desilication.
Exfoliation: It is a result but not a process. Flaking off of more or less curved sheets of shells from over rocks or bedrock results in smooth and rounded surfaces is called exfoliation.
Exfoliation domes: Large, smooth rounded domes are called exfoliation domes.
Tors: In rocks like granites, smooth surfaced and rounded small to big boulders form due to such exfoliation. It is called tors.









CHAPTER 9
During its revolution around the sun, the earth is farthest from the sun (152 million km) on 4th July, ‘t his position of the earth is called aphelion.
On 3rd January, the earth is the nearest to the sun (147 million km). This position is called perihelion.
The insolation received at the surface varies from about 320 Watt/m2 in the tropics to about 70 Watt/m2 in the poles.