In geomorphology, a butte (/bjuːt/) is an isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller landforms than mesas, plateaus, and tablelands. The word butte comes from the French word butte, meaning knoll (but of any size); its use is prevalent in the Western United States, including the southwest where mesa (Spanish for "table") is used for the larger landform. Due to their distinctive shapes, buttes are frequently landmarks in plains and mountainous areas.[1] To differentiate the two landforms, geographers use the rule of thumb that a mesa has a top that is wider than its height, while a butte has a top that is narrower than its height.[2][3]
Formation
Buttes form by weathering and erosion when hard caprock overlies a layer of less resistant rock that is eventually worn away. The harder rock on top of the butte resists erosion. The caprock provides protection for the less resistant rock below from wind abrasion which leaves it standing isolated. As the top is further eroded by abrasion and weathering, the excess material that falls off adds to the scree or talus slope around the base.[4] On a much smaller scale, the same process forms hoodoos.[5]
The term butte is sometimes applied more broadly to isolated, steep-sided hills with pointed or craggy, rather than flat, tops.[1] Three notable formations that are either named butte or may be considered buttes even though they do not conform to the formal geographer's rule are Scotts Bluff in Nebraska which is a collection of five bluffs, Crested Butte, which is a 12,168 ft (3,709 m) mountain in Colorado, and Elephant Butte, which is now an island in Elephant Butte Reservoir in New Mexico.
^Thornbury, William D. (1969). Principles of geomorphology (2d ed.). New York: Wiley. p. 133. ISBN0471861979.
^Davis, George Herbert (1999). Structural Geology of the Colorado Plateau Region of Southern Utah, with Special Emphasis on Deformation Bands. G.S.A. Special Paper 342. Boulder, Colorado: Geological Society of America. p. 30. ISBN978-0-8137-2342-6.