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The various types of weathering are :
1. Mechanical weathering
2. Chemical weathering
3. Biological weathering
Describe cirques.
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Distinguish between work of wind and work of river.
1. The work of wind is important in deserts.
2. Wind carries the material to long distances.
3. The work of wind depends on the wind velocity.
4. Wind erosion is done at slow rates.
Work of Rivers :
1. The work of river is important in humid regions.
2. The work of river is limited to its basin only.
3. The work of river depends on the slope of the landmass.
4. The erosion by rivers is very rapid.
1. Alluvial fans are formed when streams flowing from higher levels break into foot slope plains of low gradient.
2. Alluvial fans are associated with the young regimes of the running water.
3. Deposits making up alluvial fans are not sorted well.
Deltas :
1. Deltas are formed when the load carried by the rivers is dumped and spread into the sea.
2. Deltas are associated with the old regimes of the running water.
3. Deposits making up deltas are well sorted with clear stratification.
Differentiate between V-shaped valley and U-shaped valley.
1. V-shaped valleys are carved out by the river in their youthful stages.
2. They are original in nature, i.e. they are formed by the erosional actions of the rivers.
3. Their shapes are of the letter ‘V’ of english alphabet.
4. They are associated with gorges, canyon etc.
U-shaped valley:
1. U-shaped valleys are casual by glaciers in hilly regions.
2. They are modified form of pre-existing valleys.
3. Their shapes are that of the letter ‘U’ of the English alphabet.
4. They are associated with hanging valleys.
1. Continental glaciers are found in Antarctica and Greenland.
2. These are found in polar regions.
3. These are also covered in ice sheets.
4. These cover large areas.
Valley Glacier:
1. The valley glaciers are found over the Alps and the Himalayas.
2. These glaciers are found on the high mountains.
3. These do not cover large areas.
4. These are also called mountain glaciers.
The following landforms are formed due to the wind deposition:
Erosion by glaciers is tremendous because of friction caused by sheer weight of the ice. The material plucked from the land by glacier get dragged along the floors or sides of the valleys and cause great damage through abrasion and plucking. Glaciers can cause significant damage to even un-weathered rocks and can reduce high mountains into low hills and plains.As glaciers continue to move, debris gets removed, divides get lowered and eventually the slope is reduced to such an extent that glaciers will stop moving leaving only a mass of low hills and vast outwash plains along with other depositional features.
In arid regions, though rain is scarce, it comes down torrentially in a short period of time. The desert rocks devoid of vegetation, exposed to mechanical and chemical weathering processes due to drastic diurnal temperature changes, decay faster and the torrential rains help in removing the weathered material very easily.
The weathered material debris in deserts is not only moved by winds but also by rain/sheet wash. Thus, we can say that the running water is by far the most dominating geomorphic agent in shaping the earth's surface in humid as well as arid regions.
It is due to this differential availability of water in these two areas, that makes limestone to behave differently. The most dominant and almost exclusive type of geomorphic process in limestone areas is that of processes of solution and deposition by the action of the groundwater.
The erosional landforms produced by the action of the groundwater are pools, sinkholes, lapies and limestone pavements. In areas of alternating beds of rocks with limestones caves are also formed. The depositional landforms in limestone areas by the action of ground water are stalctites, stalagmites and pillars.
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chemical and physical disintegration of rocks.Sponsor Area
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animals and plantsD.
An irregular surface with sharp pinnacles, grooves and ridgesA river delta is a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or standing water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or another river that cannot transport away the supplied sediment.
Distinguish between:
i. Erosion and weathering,
ii. Oxidation and carbonation,
iii. Sand dunes and Barchans.
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