1. GE0-3112 Sedimentary processes and products
Lecture 7. Aeolian sediments
Literature:
- Leeder Ch. 16
Aeolian sediments in low-latitude deserts
(See also Ch. 8 & Ch. 13).
Geoff Corner
Department of Geology
University of Tromsø
2006

2. Contents 7.1 Aeolian environments 7.2 Desert types and distribution
7.3 Sediment flow paths
7.4 Dunes and draas
7.5 Desert facies and architecture

3. Aeolian environments Types: Characteristics:
GEO
Aeolian environments
Types:
Deserts and semi-arid regions
Beaches and sabkas
Sandy river banks
Periglacial regions
Characteristics:
Lack of vegetation
Moderate to strong winds
Mobile sand and silt sediment

4. Aeolian
GEO
Definitions
Desert: arid zone having a large deficit of precipitation (P) in relation to evaotranspiration (ET)
Definitions/subdivision (P/ET ratios):
Hyperarid: <0.03
Arid:
Semiarid:
Subhumid:

5. World distribution of deserts (arid, hyperarid) and other dry areas.
Aeolian
GEO
Southwest
N. America
Gobi
Sahara
Arabia
Atacama
(Chile)
South-central
Australia
Namib
Kalahari
Patagonia
(Argentina))
World distribution of deserts (arid, hyperarid) and other dry areas.

6. Desert types and distribution
Aeolian
GEO
Desert types and distribution
Trade wind deserts (subtropical high-pressure)
N. Africa, Arabia, south-central Australia.
Atacama, Namib (cool offshore current).
Continental deserts
Central asia.
Rain shadow/continental
western N. America, sub-Andean S. America.

7. Sub-tropical high pressure cells and trade winds.
Aeolian
GEO
Sub-tropical high pressure cells and trade winds.

8. Rain shadow effect (lower precipitation E of mountains)
Aeolian
GEO
Rain shadow effect (lower precipitation E of mountains)

9. Deserts and aeolian deposits
GEO
Deserts and aeolian deposits
Rocky deserts
Sandy deserts
Most deserts contain rock outcrops and aeolian, lake or playa, and alluvial deposits
Loess deposits in and beyond deserts

10. Distribution of aeolian deposits
GEO
Distribution of aeolian deposits
Presently active sand dunes.
Glacial maximum sand dunes.
Loess (mostly glacial maximum).

11. Sediment transport Sand Sand-flow map for Saharan ergs Aeolian
GEO
Sediment transport
Sand
Sand-flow map for Saharan ergs

12. Dust Aerosol dust budgets for the Sahara and adjacent Atlantic Oceann.
Aeolian
GEO
Dust
Aerosol dust budgets for the Sahara and adjacent Atlantic Oceann.

13. Aeolian
GEO

14. Dune types and interdune terrain
Aeolian
GEO
Dune types and interdune terrain
Bedrock and erosional forms (yardangs)
Dunes
Barchans
Transverse dunes
Linear dunes
Star dunes
Lakes and (saline) playas
Alluvial fans and stream beds

15. Saharan dunes Barchan dunes Star dunes Linear and compound dunes
Aeolian
Barchan dunes
GEO
Star dunes
Linear and compound dunes
Interdune and intererg areas
Linear dunes
Saharan dunes

16. Aeolian
GEO
Barchan dunes
Star dunes

17. Aeolian
GEO
Linear dunes

18. Linear and compound dunes
Aeolian
GEO
Linear and compound dunes

19. Aeolian
GEO
Transverse dunes?
Star dunes
Namib desert

20. Aeolian
GEO
Uluru (Ayer’s Rock),
Central Australia

21. Controls on sand deposition
Aeolian
GEO
Controls on sand deposition

22. Facies and architecture
Aeolian
GEO
Facies and architecture
Facies sequences
at the margins
of an erg.

23. Aeolian
Aeolian architecture
GEO
Interdune
Dune

24. U. Jurassic Entrada sandstone, W. USA.
Aeolian
GEO
U. Jurassic Entrada sandstone, W. USA.

25. Permian Rotliegendes, NW Europe
Aeolian
GEO
Permian Rotliegendes, NW Europe

26. Active dry phase Wet phase Formation of ’supersurface’ Aeolian
GEO
Active dry phase
Formation of ’supersurface’
Wet phase

27. Aeolian
GEO

28. Further reading Galloway & Hobday 1996. Ch. 10. Eolian systems.
Aeolian
GEO
Further reading
Galloway & Hobday Ch. 10. Eolian systems.
Kocurek, in Reading (ed.), Ch. 5. Desert aeolian systems.