Sponsor Area
Sponsor Area
2. Mud flow
3. Avalanche.
Distinguish between :
Soil and Rock.
|
Soil |
Rock |
|
1. Soil is formed due to erosion and weathering of rocks. Hence, it is an unconsolidated rock material. 2. Soil has layers which have different physical, chemical and biological properties. 3. Soils are the sources of food and moisture for plants. |
1. A rock is naturally occurring mass of solid materials. It is composed of inorganic or organic material. 2. Rock does not have layers. 3. It is not the source of food and moisture for plants. |
|
Eluviation |
Illuviation |
|
It is the mechanical translocation of clay or other fine particles down the soil profile. |
|
|
Cheluviation |
Leaching |
|
It is the downward movement of material similar to the leaching but under the influence of organic complex compounds. |
It is the removal and downward movement of material from a horizon in a solution. |
|
Earth flow |
Mud flow |
|
In hilly and mountainous regions of humid climates, water saturated soil and regolith rich in clay matters takes the form of an earth flow. Earth flow is a form of mass wasting in which behaviour of the earth material is that of a plastic solid. Solifluction is an Arctic variety of earth flow in the treeless tundra. |
Mass wasting takes the form of mud flow if proportion of water to mineral matter is large. It travels fast down the channels of stream. Mud flow also originate high in mountains where melting winter snows pick up weathered rocks rich in clay. |
|
Mechanical Weathering |
Chemical Weathering |
|
1. It is also called physical weathering. 2. It is responsible for the disintegration of rocks without changing their chemical compositions. 3. It is caused about mainly by changes in temperature and the pressing action of water. 4. It is physical break up of rocks owing to internal and external stresses caused by weathering agents. |
1. Chemical weathering includes the processes that cause rock to rot or decay due to the action of air and water on the minerals present in the rock. 2. High temperature and humidity caused the rock to decompose. 3. Chemical weathering results from the action of weak acids and gases like oxygen, carbon dioxide and hydrogen. 4. It is the process which leads to the decomposition or decay of solid rocks by means of chemical reactions. |
It is correct to say that our earth is a playfield for two opposing groups of geomorphic processes.
i. We know that the earth’s crust is dynamic and it moves vertically and horizontally. The internal forces of the earth operating within the earth which build up the crust have also been responsible for the variation in the outer surface of the crust.
ii. The external forces are involved to degrade the landforms built up by the internal forces. The action of the exogenic forces results in wearing down of relief of elevation and filling up of basins on the earth’s surface.
iii. The endogenic forces continuously elevate or build up parts of the earth’s surface and hence the exogenic processes fail to even out the relief variations of the surface of the earth.
iv. Thus variation remains as long as the opposing actions of exogenic and endogenic forces continue. So in this way our earth is a playfield for two opposing groups of processes.
The following factors are responsible for the soil formation :
1. Parent Material : The parent material is derived from the rocks. The chemical and mechanical weathering, weather the rock and produce the parent material. It is incorporated by biological remains. As the rocks are comprised of various minerals, the mineral contents are present in the parent rock. Calcium, phosphorus, nitrogen, potassium and sodium contents are found in the soil. These mineral contents and the biological remains determine the properties of the soil.
2. Climate : Climate plays an important role in the soil formation. It acts directly or indirectly. Weathering is the direct action of climate in soil formation. It depends upon the rain water and temperature. The biological action is the indirect action of climate in soil formation. It depends upon the temperature. The biological activities are limited in cold climates and intensive in humid, tropical and sub-tropical climate areas.
Soil Colour : It indicates the origin and composition of the soil. Increasing quantities of humus produce a range from white, brown to black. The presence of iron oxides and hydroxides gives it red and yellow colours.
Water Carrying Capacity : It refers to the capacity of the soil to absorb water from rain as well as from air and its capacity, to hold it.
1. Oxidation : In it the atmospheric oxygen combines with minerals of rocks. With the result, the rocks get rusted, as, iron is rusted due to the presence of air and water. Original colour changes into red, yellow or brown. The rock begins to decay and becomes a powdered dust.
2. Hydration : The chemical reaction of water with aluminium bearing minerals detaches the outer shell of such rocks through the process of hydration. Feldspar is reduced to kaolin through hydration.
3. Carbonation : Rainwater mixed with carbon dioxide is slightly acidic. It dissolves limestone, chalk and marble rocks.
4. Solution : Some of the minerals like rock salt and gypsum are dissolved in water. These minerals are dissolved in solution from the rocks.
Sponsor Area
Sponsor Area
Sponsor Area
