The document discusses various landforms found in arid and semi-arid landscapes formed by wind erosion. It describes different types of deserts including ergs which are seas of sand, regs which are desert pavements, and hamadas where bedrock predominates. It also outlines various erosional landforms caused by wind such as deflation hollows, ventifacts which are sand-blasted rock surfaces, yardangs, and different types of migrating dunes including longitudinal, transverse, barchan, and parabolic dunes. It provides examples of many of these landforms.

1. Arid and Semi-AridArid and Semi-Arid
Landscapes ( AeolianLandscapes ( Aeolian
LandformLandform

2. World's DesertsWorld's Desertsabout 1/5th
of land
Types: subtropical, rain-shadow,
coastal, interior, polar

3. Arid and Semi-aridArid and Semi-arid
EgyptLibya
Tunisia
Algeria
Morocco

4. Wind-Borne Sediment causesWind-Borne Sediment causes
deflation and abrasiondeflation and abrasion
Sahara to Caribbean
Effect on Hurricanes
Surface creep

5. InselbergInselberg
UluruUluru (Ayers Rock)(Ayers Rock)
Pediment

6. MushroomMushroom

7. Types of DesertsTypes of Deserts
Erg - sea of sand
• vegetation rare
• sand probably formed during more humid
climate

8. Death Valley, California

9. Types of DesertsTypes of Deserts
Reg - desert “pavement” of pebbles
and stones
• all small materials and sand removed by wind
• may be very thin coating of stones

10. Desert pavement

11. Hamada - bedrock predominates

12. Erosional Landform - Deflation HollowErosional Landform - Deflation Hollow
Anecdote – How fast does this occur?

13. Abrasion Origin of VentifactsAbrasion Origin of Ventifacts

14. Erosional Landforms -Erosional Landforms - VentifactsVentifacts
Wind eroded (sand blasted) surfaces

15. Erosional Landform –Erosional Landform – Yardangs andYardangs and
ZeugenZeugen
Sphinx?
White Desert, EgyptWhite Desert, Egypt

16. Dune MigrationDune Migration
Just like ripples in a stream
Windward slope
erosion and transport
Slip face (deposition)

17. Star DunesStar Dunes

18. Copyright © Frank Eckardt 2002
Star DunesStar Dunes
Variable Wind DirectionVariable Wind Direction

19. Longitudinal DunesLongitudinal Dunes
Constant wind direction, no vegetation

20. Longitudinal DunesLongitudinal Dunes
Constant wind direction, no vegetation

21. Transverse DunesTransverse Dunes
Massive volumes of sand, low consistent winds

22. Transverse DunesTransverse Dunes
Massive volumes of sand, low consistent windsMassive volumes of sand, low consistent winds

23. Barchan DunesBarchan Dunes
Isolated Dunes, low sand supply, migrating across rock

24. Barchan DunesBarchan Dunes
• Isolated – low sand supply; migrating across rock

25. Parabolic DunesParabolic Dunes
Horns pinned by plants
Typical of coasts

26. Fig. 15-12a, p. 354

27. Parabolic DunesParabolic Dunes
• Stabilized “horns" point upwind

28. A Playa in Death Valley, CaliforniaA Playa in Death Valley, California
Evaporite Pan of dried-up PlayaEvaporite Pan of dried-up Playa

29. Playas

30. Differential Erosion

33. Desert LandformsDesert Landforms
• plateaus: a broad, flat-topped area elevated
above the surrounding land and bounded, at
least in part, by cliffs
• mesa: a broad, flat-topped hill bounded by cliffs
and capped with a resistant rock layer
• butte: a narrow hill of resistant rock with a flat
top and very steep sides

34. Inselberg or Bornhardt - highly
resistant rock landform; a type of
monadnock.

35. Bornhardt, Arches National Park, Utah