Physical Geology Slides - Wind Erosion

Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay First-time Visitors: Please visitSite Map and Disclaimer. Use "Back" to return here.

---

	Some of the best examples of wind erosion are found in Antarctica, where no other processes are active. These boulders have all been deeply eroded on the right by the prevailing winds.
	A typical wind-abraded outcrop, Butler Rock, Marinette County. Typical features: fluting, high polish, gentle but extremely sharp ridges.
	The largest deflation basin in Wisconsin is near Spring Green along the Wisconsin River flood plain.
	Many deserts are covered with desert pavement, created when wind blows fine material away, leaving coarse material behind.
	The highest sand dunes in the U.S. are Great Sand Dunes in Colorado. Wind blows sand from the right but cannot carry it over the mountains as air funnels through a low pass.
	The largest dune fields in the U.S. are in, of all places, Nebraska. The Sand Hills cover much of western Nebraska. They formed during the Pleistocene from glacial debris eroded out of the Rockies, and exhibit just about every type of dune. Here we see transverse dunes several hundred meters wide and a kilometer or so long.
	These dunes in the Nebraska Sand Hills are barchan-like but much bigger and more closely-spaced than most barchans. They are severl hundred meters in size.
	This dune east of Fallon, Nevada, formed from sand blown across a wide valley. Wind funnels through the low pass, but cannot carry the sand with it.
	A "desert" pavement forming in a gravel pit near Hastings, Minnesota.
	Wind-abraded rocks are often called dreikanters from a South African word meaning "three corners." Ventifacts are common in the U.S., once you know what to look for. This perfect dreikanter was found at River Falls, Wisconsin. Most ventifacts in the northern U.S. formed during the Pleistocene when vegetation was sparse and wind-blown sand and silt was abundant.
	Every type of dune can also from in snow, but good barchans are rare. These formed near Bay Settlement in January, 1997 as snow blew across a frozen crust.
	A barchan snow drift on bay ice off Communiversity Park. The blowing snow shows the air flow over the dune. Wind chill was about -60 when the picture was taken.
	Wind-blown sand has piled against old beach terraces on the eastern side of former Lake Bonneville in Utah, outlining them clearly.
	The cap on these bluffs along the Mississippi near Alma, Wisconsin is loess, blown from the Mississippi River flood plain during the Pleistocene.

---

Return to Course Notes Index
Access class notes on wind erosion
Return to Professor Dutch's Home Page

Created 13 August 1998, Last Update 31 August 1998

Not an official UW Green Bay site