Chapter 7 Erosion. What is Erosion and Deposition? Erosion – A process that moves the sediments...
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Transcript of Chapter 7 Erosion. What is Erosion and Deposition? Erosion – A process that moves the sediments...
What is Erosion and Deposition?
• Erosion – A process that moves the sediments from one location to another, usually by gravity, glaciers, wind, or water.
• Deposition – Final step in an erosional process, sediments are dropped as their energy of motion decreases.
Erosion by Gravity
• Mass Movement – when gravity alone causes loose material to move downslope.
– Slump – one large mass of loose material moves downhill leaving a curved scar.
– Creep – sediments move downhill slowly, causing posts and trees to lean.
Glacial Erosion
• Plucking – rock fragments are loosened, broken off, and carried away by the freezing of water in rock cracks.
Wind Erosion
• Deflation – removes loose, fine-grained sediments (silt & clay), and leaves behind coarser material.
• Abrasion – wearing/scraping away by sand grains or other particles striking other sand grains and rocks, breaking off small fragments.