Weathering, Erosion and the Transport of Rock Materials essays

Weathering, Erosion and the Transport of Rock Materials essays Weathering can be considered as the breakdown of rock to form sediment. It is also regarded as the physical breakdown (disintegration) and chemical alteration (decomposition) of rocks and minerals at or near the earth's surface. The three main types of weathering are physical weathering, mechanical weathering, and chemical weathering. Mechanical weathering is the physical breakdown of rocks and minerals into smaller pieces that retain the chemical composition of the parent material. (Body from which the weathered material originated.) Once again, under mechanical weathering, there are other processes that take place such as: Frost action simply involves water creeping in rock crevices and freezing. Where the ice formed expands, it wedges itself into these crevices. This is known as Frost wedging. E.g. Talus slope, Lost River, West Virginia, USA. When ice thaws, it causes parts of the rock to be dislodged from the main body. Thermal expansion and contraction are to do with the volume of the minerals in rocks changing (expanding and contracting) in response to cooling and heating. Another important factor here is that darker minerals absorb heat faster than lighter ones. Pressure release or exfoliation would be the removal of pressure of deep burial, when rocks underneath the surface undergo immense pressure from the earth's interior heat forcing them to push through surface material breaking into leaves and sheets along joints which parallel to ground surface. E.g. Stone Mountain, Georgia, USA. Organisms such as burrowing plants and animals (rodents, worms, reptiles, etc...) also participate a lot in weathering. They construct channels through the soil mixing soil and sediment particles, allowing water and gas to go through. The roots of plants, trees and large bushes would be a nuisance in that they would force their way th ...