Presentation on theme: "Erosion and Deposition. EROSION: the movement of rock particles by wind, water, ice, or gravity - or – the process by which natural forces move weathered."— Presentation transcript:
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 EROSION 1.Gravity 2.Wind 3.Water 4.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