Dreikanter

File:Dreikanter from the Wind River Basin, Wyoming, USA. Photo by AJ Wakefield, 2012.jpg

A dreikanter from the Wind River Basin, Wyoming, USA. Property of Western Washington University. Photo by AJ Wakefield, 2012.

A Dreikanter is a type of ventifact that typically forms in desert or periglacial environments due to the abrasive action of blowing sand.

Dreikanters exhibit a characteristic three-faced pyramidal shape. The word Dreikanter is a German word meaning "three-edged."

A dreikanter is not to be confused with a zweikanter, which has only two sides, or an einkanter, which has only one windblown side.

Most places on the planet have several weathering processes acting at the same time, so finding good examples of Dreikanters is often difficult. Antarctica is a good location for finding such ventifacts since wind is usually the only active weathering agent. Many specimens in the Northeastern United States were formed during the Pleistocene era when the absence of vegetation made for little cover from wind-blown sediment.

Common Features

Some common features of Dreikanters include fluting, high polish, sharp ridges, pits, grooves, and helical forms.

File:Bradley 1930 dreikanter.jpg

Unusually large dreikanter of granite, Sweetwater County, Wyoming. This dreikanter measures 71 cm by 46 cm deep and 37 cm wide. Photo by Bradley, W.H., USGS (1930).

Formation

In areas where there is a prevailing wind, sand and debris cause a rock face to become flattened and polished. This changes the mass distribution of the rock, and may cause it to turn another surface toward the wind. If this process continues undisturbed, the resulting rock will have three distinct flattened and polished faces. Dreikanters generally form in dry, arid environments from hard rocks.

See also

• Aeolian processes
• Blowout (geology)
• Dune
• Saltation (geology)
• Yardang

External links

• An image of a Dreikanter
• Glossary of Meteorology
• The Bibliography of Aeolian Research