1. Weathering: It is the gradual loosing of rocky surfaces or substractum insitu or in place by agents of weather. There are 3 basic types of weathering which are physical, chemical, and biological.
physical weathering.
It is the disintergration of rocks in to smaller particles without change in chemical composition. This leads to rock fragmentation to pieces whose chemical composition remains the same like that of the initial rocks.
Chemical weathering.
it is the break down of rocks in which the chemical composition have not been altered.
Biological weathering.
Biological weathering involves the disintergration of rocks and minerals due to the chemical or physical agents of an organism.
CONTINENTAL DRIFT Continental drift is the idea that continents move freely over the earth surface changing their positions relative to another. Hence the theory of continental drift states that " THE EARTH WAS ONCE A SINGLE LAND MASS THAT LATER SPIT INTO BLOCKS AND DRIFTED INTO PRESENT POSITIONS AS ACONTINENTS
MASS MOVEMENT
When the gravitational force acting on a slope exceeds its resisting force, mass wasting occurs. The slope material's strength, cohesion and the amount of internal friction between materials helps maintain the slope's stability and are known collectively as the slope's shear strength. The steepness angle that a cohesion-less slope can maintain without loosing it's stability is known as its angle of response.
FACTORS INFLUENCING MASS WASTING
- Saturation of materials with water increase soil moisture. Water destroys particles cohesion and adds weight (load) hence slope failure.
- Slope stability. unconsolidated granular particles assume a stable slope. Stable slope angle is different for various materials. Over steepened slopes are unstable undercutting by stream human interference, addition of materials to the top of the slope by natural deposition and human construction causes slope failure.
- Earth quakes trigger slope instability.
- Reduction of roots holding the soil to bed rocks and weathering by frost action heaves initiates slope failure.
