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# Chapter 10: Denudation ## Syllabus - Meaning and agents of denudation: work of river and wind. - Stages of a river course and associated landforms: V-shaped valley, waterfall, meander and delta. - Wind-deflation hollows and Sand dunes. ## Denudation Denudation is the process of breaking and remo...

# Chapter 10: Denudation ## Syllabus - Meaning and agents of denudation: work of river and wind. - Stages of a river course and associated landforms: V-shaped valley, waterfall, meander and delta. - Wind-deflation hollows and Sand dunes. ## Denudation Denudation is the process of breaking and removing the rocks from the surface of the earth. It is wearing away of landmass by various processes like weathering, erosion, mass movement and transportation. It results in lowering the level of land, rounding exposed rock surfaces and leveling the peaks. ### Processes Involved in Denudation - **Weathering:** Weathering refers to the disintegration of rocks by atmospheric agents at or near the surface of the earth. It happens due to a change in weather conditions like temperature, moisture and precipitation. - **Erosion:** Erosion refers to the displacement of rocks by agents like wind, water or ice. Erosion is caused by the movement of these eroding agents and the resulting smaller particles are transported to another place, whereas in weathering no such movement occurs. - **Mass Movement or Mass Wasting:** Mass Movement or Mass Wasting refers to the large-scale movement of loose materials (rock-waste) down the slope on account of gravity. The steeper the slope, the more rapid is the movement. ## Work of the River: ### Young Stage - **Effect on River:** gorge, rapids, waterfalls - **Work of the River:** predominantly erosion ### Maturity Stage - **Effect on River:** meanders, river cliffs - **Work of the River:** transportation (some deposition) - **Effect on Land:** Valley Widening Open, wide gentle-sloping valley ### Old Stage - **Effect on River:** deltas, flood plains, ox-bow lakes - **Work of the River:** deposition - **Effect on Land:** Alluvium Deposition, very gently-sloping, smooth, wide valley ## Transportation and Deposition - **Transportation:** Material gets loosened and transported to the other place by various agents like wind and ice. - **Deposition:** Material that has been transported by wind and ice gets deposited at a particular place called the depositional plane. - **Agents of Deposition:** The four active agents of denudation are wind, waves, ice and running water. We will study more about these agents in detail while discussing the chapters of wind, waves and glacial erosion.