Geology



Geology-Assignment

Soil horizon

Soil horizon can simply be defined as a layer in a soil profile. The layer is usually parallel with the surface of land. The properties of these layers are developed with the help of percolating water and living organism's combined actions. More than one horizon can be found in the soil surface depending upon the intensity and affects of these combined actions.

Mechanical weathering

Breaking a rock or mineral into smaller pieces without changing its chemical makeup is known as mechanical weathering. So, simply mechanical weathering is a breaking into smaller pieces of rocks. This process is pretty simple, let's take a simple example of this breaking of rock into small pieces. We usually see cracks in rocks, due to the cracks water enters into the cracks. As the drop in temperature occurs water in the cracks freezes and then expands against walls of rock. Finally, the rock is dislodged due to enlargement in the cracks of the rocks. There are usually four types of mechanical weathering including frost weathering, salt weathering, and chemical exfoliation.

Chemical weathering

This is similar to that of mechanical weathering but the main agent here is chemical. In chemical weathering changing the composition of minerals and rocks occur so as to increase the stability of the rocks. So, Chemical weathering breaks down minerals and rocks. Oxidation, dissolution, and hydrolysis are the common type of chemical weathering (Monroe et al., 2007). Due to oxidation the rocks forms crust. This occurs as the oxygen and mineral ions combine together to form an oxide. Similarly, caves are produces due to dissolution as the soluble compounds such as limestone, are dissolved. Finally, the hydrolysis forms the clay minerals.

Spheroidal weathering

It is the type of chemical weathering in which larger-scale exfoliation is produces which is similar to mechanical weathering.

Leaching

Leeching basically occurs in the upper layer of the soil by percolating precipitation, in this loss of soluble substances and colloids occurred. These lost soluble substances are travelled to lower level layer of the soil. Leaching increases with the increase in temperatures, rainfalls etc.

Creep

It is the slowest type of flow and is the imperceptible down slop movement of rock or soil. Most the time, the evidence of creep comes from its effects such as tilted trees and power poles, broken streets and sidewalk, and cracker retaining walls or foundation. Creep is the most widespread and significant mass-wasting process in terms of ...