structural landform

structural landform

      any topographic feature formed by the differential wearing away of rocks and the deposition of the resulting debris under the influence of exogenetic geomorphic forces. Such forces operate at the interface of the planetary atmosphere, lithosphere, cryosphere, and hydrosphere. The processes generating these forces are the major agents of erosion, transport, and deposition of debris. They include fluvial, eolian, glacial, groundwater, and coastal-marine processes, as well as those associated with mass movement.

      Structural landforms result from forces generated by such processes interacting with the resistances imposed by rocks and sediments. For change to occur, the forces must exceed the thresholds of resistance imposed by the earth materials on which they act. The landform itself, however, may alter the forces by developing specific shapes. Sand dunes, beaches, river valleys, and glacial drumlins are all examples of landforms that modify the forces imposed upon them. Such self-regulation of landform development is a quality of landscapes that achieve equilibrium.

      Although structure and lithology establish the resistance factors for structural landforms, climate defines the nature of the exogenetic geomorphological processes. In cold regions ice-related processes dominate in the development of landscapes, while in warm-wet regions fluvial processes exert primary control. Thus, a climatically controlled style of landscape development is imposed on the structurally defined surface. Moreover, process and structure interact through geologic time on an evolving landscape. As pointed out by the eminent William Morris Davis, landscape is a function of the trilogy of structure, process, and time.

Victor R. Baker

Additional Reading
Landforms resulting from erosion and deposition are analyzed in Richard J. Chorley, Stanley A. Schumm, and David E. Sugden, Geomorphology (1984); and Dale F. Ritter, Process Geomorphology, 2nd ed. (1986).Victor R. Baker

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • structural bench —    A shelf or step like landform produced or controlled by erosion resistant, horizontally bedded rock. Erosion removes overlying weaker rock or sediment forming a nearly level to gently inclined surface that rests on a relatively resistant… …   Glossary of landform and geologic terms

  • structural back slope —    (not recommended)    use dip slope …   Glossary of landform and geologic terms

  • Landform — In the earth sciences and geology sub fields a landform or physical feature comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element… …   Wikipedia

  • landform — /land fawrm /, n. Geol. a specific geomorphic feature on the surface of the earth, ranging from large scale features such as plains, plateaus, and mountains to minor features such as hills, valleys, and alluvial fans. [1890 95; LAND + FORM] * * * …   Universalium

  • continental landform — ▪ geology Introduction       any conspicuous topographic feature on the largest land areas of the Earth. Familiar examples are mountains (including volcanic (volcanism) cones), plateaus, and valleys. (The term landform also can be applied to… …   Universalium

  • Erg (landform) — For other uses, see Erg (disambiguation). Issaouane Erg, Algeria. (31°11 …   Wikipedia

  • strike —    [ structural geology ]    The compass direction or trend taken by a structural surface (e.g., a bed or fault plane) as it intersects the horizontal; used in combination with “dip” to describe the orientation of bedrock strata.    SW & GG …   Glossary of landform and geologic terms

  • fold —    [ structural geology ]    A curve or bend of a planar structure such as rock strata, bedding planes, foliation, or cleavage.    GG …   Glossary of landform and geologic terms

  • homoclinal —    [ structural geomorphology ]    (adjective)    Pertaining to strata that dip in one direction with a uniform angle.    Compare: cuesta, hogback, homoclinal ridge.    HP …   Glossary of landform and geologic terms

  • anticline —     a) [ landform ]    A unit of folded strata that is convex upward and whose core contains the stratigraphically oldest rocks, and occurs at the earth’s surface. In a single anticline, beds forming the opposing limbs of the fold dip away from… …   Glossary of landform and geologic terms

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”