Monadnock

Monadnock

A monadnock[pronunciation?] or inselberg is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain. In southern and southern-central Africa, a similar formation of granite is known as a kopje, a Dutch word from which the Afrikaans word koppie[1] was derived.

Contents

Definitions

Monadnock is an originally Native American term for an isolated hill or a lone mountain that has risen above the surrounding area, typically by surviving erosion. Geologists took the name from Mount Monadnock in southwestern New Hampshire.[2] It is thought to derive from the Abenaki language, from either menonadenak ("smooth mountain") or menadena ("isolated mountain").[3] In this context, monadnock is used to describe a mountain that rises from an area of relatively flat and/or lower terrain. For instance, Mount Monadnock rises 2,000 feet (610 m) above its surrounding terrain and stands, at 3,165 feet (965 m), nearly 1,000 feet (300 m) higher than any mountain peak within 30 miles (48 km).[4]

Sugarloaf Mountain, Rio de Janeiro

The word inselberg is German for "island mountain"; the name was originally coined by geologist Wilhelm Bornhardt (1864–1946) in 1900 to describe the abundance of such features found in southern Africa.[5] At this point, the term applied only to arid landscape features. However, the term inselberg has since been used to describe a broader geography and range of rock features, leading to confusion about the precise definition of the term. In a 1973 study examining the use of the term, one researcher found that the term had been used for features in savannah climates 40% of the time; arid or semi-arid climates 32% of the time, humid-subtropical and arctic 12% of the time; and 6% each for humid-tropical and Mediterrainean climates. As recently as 1972, the term has been defined as "steep-sided isolated hills rising relatively abruptly above gently sloping ground." This definition includes such features as buttes; conical hills with rectilinear sides typically found in arid regions; regolith-covered concave-convex hills; rock crests over regolith slopes; rock domes with near vertical sides; tors (koppies) formed of large boulders but with solid rock cores. Thus, the term monadnock and inselberg may not perfectly match.[6]

Geology

Volcanic or other processes may give rise to a body of rock resistant to erosion, inside a body of softer rock such as limestone which is more susceptible to erosion. When the less resistant rock is eroded away to form a plain, the more resistant rock is left behind as an isolated mountain. The strength of the uneroded rock is often attributed to the tightness of its jointing. If the monadnock is dome-shaped and formed from granite-gneiss, it can also be called a bornhardt.[7]

The presence of a monadnock or inselberg typically indicates the existence of a nearby plateau or highland, or their remnants. This is especially the case for inselbergs composed of sedimentary rock, which will display the same stratigraphic units as this nearby plateau. However once exposed, the inselbergs are destroyed by marginal collapse of joint blocks and exfoliation sheets. This process leaves behind tors perched at their summits and overtime a talus-bordered residual, known as a castle kopje appears.[8] [9]

Ecology

A duri crust inselberg near Dori, Burkina Faso

The kopjes of Eastern Africa tend to be a refuge for life in the Serengeti of Tanzania and Kenya. Where the soil is too thin or hard to support tree life in large areas, soil trapped by kopjes can be dense with trees while the surrounding land contains only short grass. Hollows in the rock surfaces provide catchments for rainwater.[10] Many animals have adapted to the use of kopjes, to include the lion, hyrax, and an abundance of bird and reptile life.

See also

References

  1. ^ Webster's New Explorer Dictionary of Word Origins (2004). Federal Street Press: New York.
  2. ^ Raymo, Chet and Maureen E. (1989) Written in Stone: A Geologic History of the Northeastern United States. Globe Pequot, Chester, Connecticut.
  3. ^ "Vermont Soils with Names of American Indian Origin" United States Department of Agriculture, Natural Resources Conservation Service. Retrieved January 6, 2008.
  4. ^ Baldwin, Henry I. (1989). Monadnock Guide 4th edition. Concord, New Hampshire: Society for the Protection of New Hampshire Forests.
  5. ^ Holmes, Arthur (1978). Holmes Principles of Physical Geology Taylor & Francis: New York.
  6. ^ Gerrard, John (1988). Rocks and Landforms Routledge: Florence, Kentucky.
  7. ^ "A Dictionary of Ecology" (2004). Encyclopedia.com. Retrieved November 28, 2009 <http://www.encyclopedia.com>
  8. ^ "Summary: Inselbergs/Hills/Knobs" Desert Processes Working Group; Knowledge Sciences, Inc. Retrieved January 6, 2008.
  9. ^ Easterbrook, Don J. "Chapter Three: Weathering." Surface Processes and Landforms. 2nd ed. Upper Saddle River, NJ: Prentice Hall, 1999. 45. Print.
  10. ^ Serengeti National Park Visitor Center, Tanzania

External links

 Chisholm, Hugh, ed (1911). "Monadnock". Encyclopædia Britannica (11th ed.). Cambridge University Press.  Media related to Monadnocks at Wikimedia Commons


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Look at other dictionaries:

  • monadnock — MONADNÓCK s.n. (geol.) Munte izolat în cadrul unui relief coborât, alcătuit din roci dure. [< fr. monadnock, cf. Monadnock – munte din sudul S.U.a. < cuv. indian]. Trimis de LauraGellner, 14.06.2005. Sursa: DN  MONADNÓCK s. n. munte izolat …   Dicționar Român

  • Monadnock — bezeichnet: eine Ortschaft in New Hampshire Monadnock (Stadt) einen Wanderweg: Metacomet Monadnock Wanderweg ein Gebäude: Monadnock Building einen Inselberg Diese Seite ist eine Begriffskläru …   Deutsch Wikipedia

  • monadnock — ● monadnock nom masculin (du nom d un sommet de la Nouvelle Angleterre) Relief résiduel dominant une pénéplaine à laquelle il se rattache progressivement. monadnock [mɔnadnɔk] n. m. ÉTYM. 1928, Baulig, in Rey Debove et Gagnon; mot angl. (1895,… …   Encyclopédie Universelle

  • monadnock — ☆ monadnock [mə nad′näk΄ ] n. [after Mt. Monadnock, N.H.] Geol. an isolated rocky hill or mountain rising above a peneplain in an area with a temperate climate: cf. INSELBERG …   English World dictionary

  • monadnock — /meuh nad nok/, n. 1. Physical Geog. a residual hill or mountain standing well above the surface of a surrounding peneplain. 2. (cap.) Mount, a mountain peak in SW New Hampshire. 3186 ft. (971 m). [1735 45, Amer.; after (Grand) Monadnock (earlier …   Universalium

  • Monadnock — Inselberg  Ne doit pas être confondu avec Tuya ou Mesa. Un inselberg près de Dori, au Burkina Fa …   Wikipédia en Français

  • monadnock — noun A hill or mountain standing isolated above a predominately flat plain. Eastward from the White Mountains, the open sea of the upland country comes right to the monadnock shore, with hardly an outlying island; southward the upland is covered… …   Wiktionary

  • monadnock — noun Etymology: Mt. Monadnock, New Hampshire Date: 1893 inselberg …   New Collegiate Dictionary

  • monadnock — [mə nadnɒk] noun an isolated hill or ridge of erosion resistant rock rising above a peneplain. Origin C19: named after Mount Monadnock in New Hampshire, US …   English new terms dictionary

  • monadnock — /məˈnædnɒk/ (say muh nadnok) noun a residual hill or mountain standing well above the surface of the surrounding eroded country. {named after Mount Monadnock, New Hampshire, US; from a Native American: (object) standing out, isolated} …  

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