Texture (geology)

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In geology, texture is the spatial (three-dimensional) arrangement of structural elements of a rock as well as the distribution, spatial position and filling of the rock components. Minerals and mineral aggregates (mineral grains connected in association) can either be distributed unregulated and homogeneously in the rock (directionless) or form flat or linear structures due to inhomogeneities , for example streaks or a fluid texture .

Differentiation from the term "structure"

The description of the texture as a representation of the arrangement and distribution of structures in space is an element of the description of rocks ( petrography ). It is to be distinguished from the ' structure ' , which examines the rock components for their shape (or crystal form) and mutual delimitation (e.g. glassy structure, granular, porphyry , ophitic ). Both terms are summarized under the term 'structure', i.e. the general description of the spatial location of the mixture parts. The primary structure includes u. a. the stratification, to the secondary structure the foliation.

This definition applies in the German-speaking world, while in English or French the terms structure and texture sometimes have different or opposing meanings.

Examples

The stratification occurs in sediments due to differences in material or grain size . A planar texture in metamorphic rocks is the Foliationstextur a mica slate , in which one or more foliation surfaces ( foliations can split the rock in numerous thin body). Linear textures are also created by tectonic deformation, such as the elongation of rock elements and minerals or the adjustment of the preferred crystallographic orientation. Further examples are the fluid texture or streak texture of igneous rock.

See also

literature

  • Gerhard H. Eisbacher: Introduction to Tectonics . 2nd Edition. Ferdinand Enke Verlag, Stuttgart 1996, ISBN 3-432-99252-1 , p. 166 f .
  • Rudolf Hohl (ed.): The history of the development of the earth . 6th edition. Werner Dausien Verlag, Hanau 1985, ISBN 3-7684-6526-8 , p. 1-703 .
  • Hans Murawski: Geological Dictionary . 10th edition. Ferd. Enke Verlag, Stuttgart 1998, ISBN 3-432-84100-0 , p. 278 .

Individual evidence

  1. ^ A b Dieter Richter: General Geology . 3. Edition. de Gruyter Verlag, Berlin - New York 1985, ISBN 3-11-010416-4 , pp. 276 f .