4. Eolian Landforms

5. Wind An agent of erosion –“eolian” refers to wind 2 types of eolian erosion: –abrasion: sandblasting YARDANG –deflation: blowing away loose particles DESERT PAVEMENT

10. Dust storms and sand storms Dust Storm: –strong winds –sparsely vegetated –dust is carried high into air; dark cloud

15. Dust storms and sand storms Sand Storm: –sand can be carried only 1-2 meters high –can be heard –sand moves by SALTATION

18. DUNE Accumulation of sand, shaped by wind Dunes have windward and leeward slopes

20. angle of repose Angle at which loose material is stable 30 – 34 ° for sand

21. Types of Sand Dunes: 1.Barchan –point downwind –windward slope is gradual –leeward slope is steeper

24. Types of Sand Dunes: 2. Transverse: waves of sand crests are perpendicular to wind

27. Types of Dunes 3. Barchanoid ridge of coalesced barchans

30. Types of Sand Dunes: 4. Parabolic: point upwind vegetation anchors arms large blowout depression in center

34. Coastal Blowout Dune –a type of parabolic –coastal location (Great Lakes) –point upwind

39. Hairpin –type of parabolic –long and narrow –point upwind

40. 5. Longitudinal –parallel to wind direction

44. 6. Star Dunes –wind from all directions

46. Loess Silt-sized, wind-deposited deposit From outwash deposits of Pleistocene glaciers