Erosion & Deposition

Erosion the process by which natural forces move weathered rock and soil from one place to another

Causes of Erosion Gravity Running water Wind Glaciers

Causes of Erosion Gravity = force that moves rock and other materials downhill –Mass movement—process of moving sediment downhill –May be fast or slow

Causes of Erosion Gravity –Force that moves rock and other materials downhill –Mass movement—process of moving sediment downhill –May be fast or slow –Types of mass movement: LandslidesLandslides—rock & soil quickly slide quickly down a steep slope

Causes of Erosion Gravity –Force that moves rock and other materials downhill –Mass movement—process of moving sediment downhill –May be fast or slow –Types of mass movement: MudflowsMudflows—rapid downhill movement of a mixture of water water, rock, and soil

Causes of Erosion Gravity –Force that moves rock and other materials downhill –Mass movement—process of moving sediment downhill –May be fast or slow –Types of mass movement: Slumponelarge massSlump—one large mass of rock and soil suddenly slips down a slope

Causes of Erosion Gravity –Force that moves rock and other materials downhill –Mass movement—process of moving sediment downhill –May be fast or slow –Types of mass movement: CreepveryslowCreep—very slow downhill movement of rock and soil

Causes of Erosion Running Water = #1 agent of erosion

Causes of Erosion Running Water –#1 agent of erosion –Types of running water: StreamsStreams –Small streams = creeks –Large streams = rivers Colorado River Grand Canyon

Causes of Erosion Running Water –#1 agent of erosion –Types of running water: Streams WavesWaves

Causes of Erosion Wind = Blows sediment Dust Bowl Sand dunes

Causes of Erosion Glaciers = Large masses of moving ice –Movement changes the land beneath beneath them Alaska

Deposition the natural process of laying down sediments in a new location –creates new landforms

Deposition the natural process of laying down sediments in a new location –creates new landforms: Oxbow lakeOxbow lake— deposition blocks off part of a river

Deposition the natural process of laying down sediments in a new location –creates new landforms: DeltaDelta— sediment is deposited at end the end of a river

Deposition deposited sediments are laid down in layers layers of sediment are compacted under pressure and eventually form sedimentary rock

Deposition deposited sediments are laid down in layers Layers of sediment are compacted under pressure and eventually form sedimentary rock Sedimentary rocks are like ogres and onions…they have layers.

Deposition deposited sediments are laid down in layers Layers of sediment are compacted under pressure and eventually form sedimentary rock Most fossils are found in sedimentary rocks because organisms get covered and preserved by the layers then mineral replacement occurs over time.

Weathering, erosion and deposition are all part of a never-ending cycle that constantly shapes and reshapes the land.

Weathering, erosion and deposition are all part of a never-ending cycle that constantly shapes and reshapes the land. Destructive forces—break down Constructive forces—build up

Weathering, erosion and deposition are all part of a never-ending cycle that constantly shapes and reshapes the land. Destructive Forces Constructive Forces