Erosion and Deposition

Erosion is the movement of sediment by wind, ice, water, or gravity. What is Erosion? Erosion is the movement of sediment by wind, ice, water, or gravity.

What is Deposition? The process by which sediment drops out of the wind, water, ice, or gravity that carried it.

Gravity Sediment falls

Gravity Erosion Angle of Repose is the steepest angle, or slope at which a material will not slide down.

gravity moves material down a slope Gravity Deposition Mass Movement gravity moves material down a slope Landslide - rock & soil quickly move Slump – rock & soil suddenly fall, big mass Creep –rock and soil slowly move Mudflow - mud Avalanche - snow

What type of mass movement is each picture? LANDSLIDE MUDFLOW 2 1 What type of mass movement is each picture? http://classes.colgate.edu/dkeller/geol101/massw/mass.htm CREEP SLUMP 4 3

Ice (glaciers) carry sediment.

Ice Erosion Continental Glaciers – covers continent. Flattens / smoothes land Kettle Lakes Alpine Glacier – in the mountains. Land made rugged. Horns – sharp pyramid shaped peaks U-Shaped Valleys

Ice Deposition Tills – unsorted, deposited rock material Moraines – ridges along edge of glacier Stratified Drift – layers of rock deposited based on size Outwash plain – large area of drift

Which type of glacier or landform is represented in each picture? Continental Glacier Alpine Glacier 2 1 2 1 Which type of glacier or landform is represented in each picture? www.uwsp.edu/.../lecture_glacial_processes.html Kettle U Shaped Valley 3 4 3 4

What did glaciers create in each picture? 1 2 Outwash Plain Southeast, Alaska Moraine Thompson Glacier, Canadian Arctic What did glaciers create in each picture?

Wind Wind blows sediment.

Wind Deposition Sand Dunes – mounds of wind deposited sand. Move in direction of wind. Loess – thick deposits of fine-grained, wind blown sediment http://www.nwlg.org/pages/resources/geog/hydro_cycle/dunes/stop7b.htm

Water Water (rivers, oceans, rain, etc.) washes sediment after being weathered

Water Erosion Sea Cliffs – rock wears away Sea Caves – hole in rock created by waves near cliff Sea Arches – waves cut hole completely through rock in a sea cave Sea Stacks – offshore column of rock once connected to the mainland

What did water erosion create in each of these pictures? 5 SEA ARCH 2 3 1 2 1 1 3 SEA CAVE SEA CLIFFS 4 5 6 4 2 4 SEA STACKS What did water erosion create in each of these pictures?

Water Deposition Deltas – slow river current drops sediment in fan-shaped pattern at end of river Sand Bars – offshore deposit of sand, gravel, or shell material Alluvial Fans Beaches – deposited sand

What did water create in each of these pictures? http://www.school-portal.co.uk/GroupDownloadFile.asp?file=21604 5 2 3 1 2 SANDBAR DELTA BEACH 1 4 4 6 4 ALLUVIAL FAN What did water create in each of these pictures?