Class 11, Sand dunes
-
Upload
scott-st-george -
Category
Education
-
view
640 -
download
1
Transcript of Class 11, Sand dunes
![Page 1: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/1.jpg)
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
![Page 2: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/2.jpg)
Photograph: kcspor!our
![Page 3: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/3.jpg)
Sand and loess deposits in the United States Sun and Muhs 2007
![Page 4: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/4.jpg)
Global distribution of aeolian sand Sun and Muhs 2007
![Page 5: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/5.jpg)
Lt. G.K. Warren’s sketch of the Nebraska Sand Hills, 1855
![Page 6: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/6.jpg)
Source: Stephen Wolfe
![Page 7: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/7.jpg)
“...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
![Page 8: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/8.jpg)
![Page 9: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/9.jpg)
Source: Hughenholtz et al., Aeolian Research (2010)
![Page 10: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/10.jpg)
Were these dune fields more active prior to the 20th century?
![Page 11: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/11.jpg)
Photograph: Stephen Wolfe
![Page 13: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/13.jpg)
Impurities or defects in this structure can act as “traps” for free electrons.
![Page 14: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/14.jpg)
free electron
![Page 15: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/15.jpg)
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.
![Page 18: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/18.jpg)
![Page 19: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/19.jpg)
Source: Wolfe et al., Geographie physique et Quaternaire, 2002
![Page 20: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/20.jpg)
Photograph: Stephen Wolfe
![Page 21: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/21.jpg)
![Page 22: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/22.jpg)
Stephen Wolfe Geological Survey of Canada
![Page 23: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/23.jpg)
Source: Stephen Wolfe
![Page 24: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/24.jpg)
Source: Wolfe et al., Geographie physique et Quaternaire, 2002
![Page 25: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/25.jpg)
Source: Wolfe and Hughenholtz, Geology, 2010
![Page 26: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/26.jpg)
Source: Stephen Wolfe
![Page 27: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/27.jpg)
Light Detection and Ranging (LiDAR)
![Page 28: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/28.jpg)
Source: Wolfe and Hughenholtz, Geology, 2010
barchan dune
parabolic dune
back ridgeresidual
dune ridges
![Page 29: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/29.jpg)
Parabolic dunesPhotograph: Shooting Chris
![Page 30: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/30.jpg)
Barchan dunesPhotograph: Ron Scho!
![Page 31: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/31.jpg)
![Page 32: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/32.jpg)
S TA B L E I S O T O P E S I N P A L E O C L I M AT O L O G Y
![Page 33: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/33.jpg)
less O18“depleted”
more O18“enriched”
more O18
“enriched”
less O18“depleted”
![Page 34: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/34.jpg)
Source: Jouzel et al., Journal of Geophysical Research, 1994
![Page 35: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/35.jpg)
Source: Jouzel et al., Journal of Geophysical Research, 1994
“light”
“heavy”
![Page 36: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/36.jpg)
“more positive” δO18 = “heavy” = “enriched”for example, ocean water
![Page 37: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/37.jpg)
“more negative” δO18 = “light” = “depleted”for example, glacial ice
![Page 38: Class 11, Sand dunes](https://reader033.fdocuments.in/reader033/viewer/2022061518/55a02aab1a28ab081f8b45e8/html5/thumbnails/38.jpg)
Source: Bowen and Wilkinson, Geology, 2002
δO18 in precipitation