3. Wind Erosion

Common in Dry Climates (deserts) and along shorelines

Dunes Dunes – gentle slopes faces the wind Wind only pick up and carry clay, silt and sand

WIND

desert wind erosion pitted

Sand Blasted and Pitted Rock Sand can only be picked up, up to 3 feet so lower parts get eroded away also get pitted rocks

Cross bedded deposits

deposits from ripples and dunesdunes indicate that the depositional environment was either water or winddepositional environment

4. WAVES

ABRASION

Longshore Current Movement of sediment parallel to the shore as waves strike shoreline at an angle Waves hit at an angle, water washes back

4MmEshttp:// 4MmEs 8r0&list=PLB177833E87DA5C20http:// 8r0&list=PLB177833E87DA5C20

Mass Movement

Mass Movements –The downslope movement of large masses of earth materials due to _______ gravity

Three Main Types  Creep  Landslides  Mudflows

Creep Gradual downhill movement of soil Slow process Evidence: (tilted fences, utility pole, bent trees)

Landslides Sudden and rapid downhill movement Likely to occur on steep slopes Caused by high precipitation which “lubricates” sediment (deceases friction)

Slump La Conchita, CA Spring 1995

Rockslide Porteau Cove, B.C July 30, 2008

Tully Landslide April 27, 1993

Mudflow Cause - Fine-grained sediment becomes saturated with water and begins to flow Likely to occur on steep slopes Fast and destructive

Mt. Saint Helen’s, WA, Lahar March 21, 1982