Erosion and Deposition

EROSION: the movement of rock particles by wind, water, ice, or gravity - or – the process by which

natural forces move weathered rock and soil from one place to another.

AGENTS OF EROSION1.Gravity2.Wind3.Water4.Glaciers

DUST BOWL: The Dust Bowl included western Oklahoma and parts of the surrounding states. Wind blew dry particles of soil into great clouds of dust that traveled thousands of kilometers. (Dirty Thirties – Dust Bowl lasted from 1930-1938) (Wind Erosion)

HowStuffWorks Videos "American Grasslands: The Dust Bowl"

**Plowing removed the grass from the Great Plains and exposed the soil. In times of drought, the topsoil quickly dried out, turned to dust, and blew away.

SOIL CONSERVATION: the management of soil to prevent its destruction.

1.contour plowing – the practice of plowing fields along curves of a slope

2. conservation plowing – disturbs the soil and its plant cover as little as possible.

SEDIMENT: material moved by erosion

MASS MOVEMENT: any one of several processes that move sediment downhill.

**Mass Movement can be fast or slow.

HowStuffWorks Videos "How Mudslides Work"

**Gravity is the force that moves rock and other materials downhill.

RUNOFF: water that flows over the ground surface rather than soaking into the ground

FLOOD PLAIN: the flat, wide area of land along a river.

ALLUVIAL FAN: a wide, sloping deposit of sediment formed where a stream leaves a mountain range. It is shaped like a fan.

**Deposition occurs where the agents of erosion lay down the sediment. Deposition changes the shape of the land.

**Weathering, erosion, and deposition act together in a cycle that wears down and builds up Earth’s surface.

Beach: is an area of wave-washed sediment along a coast

• Tombolo: an island is attached to the mainland by a narrow piece of land such as a spit or bar.

Deposition (cont.)

• Spit : a beach that projects like a finger out into the water.

• Sand Dune: A deposit of wind-blown sand.• Sandbar: a somewhat linear landform within

or extending into a body of water, typically composed of sand, silt or small pebbles. Sandbar can appear in the sea, in a lake, or in a river. EX. a spit

Types of Deposition

sandbar Spit

Sand Dune