Chapter 7 Erosion

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.

Glaciers Glaciers are a mass of snow and ice that move slowly downhill due to its weight.

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.

Other types of wind erosion Sand Storm Dust Storm