Earth pyramid

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Renon Earth Pyramids in South Tyrol (Northern Italy)
Steinegger earth pyramids in South Tyrol
Earth pyramids of Segonzano in Trentino (Northern Italy)

Erdpyramiden (also called "Erdpfeiler") are steep, tower or conical erosion form of relatively easily erodable rock (z. B. weakly cemented sandstone , loess , boulder clay , volcanic tuff ), which complete by resting blocks of less erodible material before Removal has been preserved so far.

Emergence

Preconditions for the formation of earth pyramids are certain properties of the material (relative fine-grainedness, low, but not too low consolidation ), the climate (regular precipitation), a location sheltered from the wind and the occurrence of larger stones or boulders made of erosion-resistant solid rock ( e.g. igneous rock or gneiss ) in the fine-grained material. In many cases, the parent rock is therefore Pleistocene boulder clay or boulder clay .

The formation takes place as follows:

  1. The starting point for the formation of earth pyramids is the exposure of a sediment body with corresponding properties on a relatively steep slope.
  2. Rainwater that runs off the surface cuts deep furrows (flushing grooves that widen into gullies ) in the slope or the sediment body. Individual blocks of solid rock, which occur naturally in the eroding sediment body, protect the underlying, fine-grained material. As a result, this erodes much more slowly than unprotected material. More or less high columns of fine-grained sediment remain below such a stone, among other things because the sheltered location ensures that rain can only attack directly from above.
  3. If a pillar loses its capstone, it then erodes relatively quickly. It takes on the shape of a sugar loaf and gets smaller and smaller until it finally disappears completely. Meanwhile, new earth cones are forming further up on the slope ( receding erosion ).

Examples of earth pyramids

Earth pyramids are found worldwide; Examples of earth pyramids are:

Bulgaria

France

Italy

Norway

Austria

Switzerland

Serbia

Turkey

literature

  • Hans Becker: About the emergence of earth pyramids (= news from the Academy of Sciences in Göttingen. Mathematical-physical class. Born in 1963, No. 12, ISSN  0065-5295 ). Vandenhoeck & Ruprecht, Göttingen 1963.
  • Hans Becker: Comparative consideration of the formation of earth pyramids in different climatic areas of the earth (= Cologne geographical works. Vol. 17, ISSN  0454-1294 ). Geographical Institute of the University of Cologne, Cologne 1962 (At the same time: Cologne, University, dissertation, from June 23, 1962).

Web links

Commons : Earth Pyramids  - collection of images, videos and audio files