1. R E L I C D U N E F I E L D S I N N O R T H A M E R I C A

2. Photograph: kcspor our

3. Sand and loess deposits in the United States Sun and Muhs 2007

4. Global distribution of aeolian sand Sun and Muhs 2007

5. Lt. G.K. Warren’s sketch of the Nebraska Sand Hills, 1855

6. Source: Stephen Wolfe

7. “...the men and horses were in great want
of water, and the heat was very great while
travelling through miles of burning sand.”
Captain John Palliser, 1863

9. Source: Hughenholtz et al., Aeolian Research (2010)

10. Were these dune fields
more active prior to the 20th century?

11. Photograph: Stephen Wolfe

12. Photograph: baba1627

13. Impurities or defects in this structure can act as
“traps” for free electrons.

14. free
electron

15. The rate at which free electrons are produced,
and traps are filled, is proportional to:
• the amount of radioactive elements in the
minerals being dated
• the amount of radioactive elements in
their surroundings.

16. Photograph: Ben+Sam

17. Photograph: Pandiyan

19. Source: Wolfe et al., Geographie physique et Quaternaire, 2002

20. Photograph: Stephen Wolfe

22. Stephen Wolfe Geological Survey of Canada

23. Source: Stephen Wolfe

24. Source: Wolfe et al., Geographie physique et Quaternaire, 2002

25. Source: Wolfe and Hughenholtz, Geology, 2010

26. Source: Stephen Wolfe

27. Light Detection and Ranging (LiDAR)

28. Source: Wolfe and Hughenholtz, Geology, 2010
barchan dune
parabolic dune
back ridge
residual
dune ridges

29. Parabolic dunes
Photograph: Shooting Chris

30. Barchan dunes
Photograph: Ron Scho

32. S TA B L E I S OTO P E S I N PA L E O C L I M ATO LO GY

33. less O18
“depleted”
more O18
“enriched”
more O18
“enriched”
less O18
“depleted”

34. Source: Jouzel et al., Journal of Geophysical Research, 1994

35. Source: Jouzel et al., Journal of Geophysical Research, 1994
“light”
“heavy”

36. “more positive” δO18 = “heavy” = “enriched”
for example, ocean water

37. “more negative” δO18 = “light” = “depleted”
for example, glacial ice

38. Source: Bowen and Wilkinson, Geology, 2002
δO18 in precipitation