Bank (petrology)

from Wikipedia, the free encyclopedia
Limestone banks of the Blue Lias Formation (Lower Jurassic) on the cliffs at Lyme Regis , Dorset, England, clearly wafting out between dark claystones

In geology, bank generally refers to a rock layer with thicknesses in the centimeter to meter range, which differs in its individual characteristics ( color , texture , material) from the layers directly overlying and underlying it. The term is mainly used when such a layer clearly emerges from the rock structure, because those overlying and underlying layers in the outcrop form a layered joint accentuated by weathering . A larger body of rock, which is mainly made up of such banks, is called banked . The structure of a rock from banks or its peculiarities are called banking . Banks are mainly found in sedimentary rocks (including loose sediments) and pyroclastics , less often in lava rocks .

In lithostratigraphy , the bank or layer ( Latin stratum , English bed , layer , abbreviated Bk. Or Lg. ) Is defined as the smallest mappable unit, but only particularly conspicuous, laterally long and thus stratigraphically particularly important banks are assigned their own Names provided and identified as formal lithostratigraphic units. For more information, see →  Bank (Stratigraphy) .

In the geological sense, the bank should not be confused with the gravel or sand bank , which denotes sediment washed up on the surface of the terrain or at the bottom of bodies of water.


Hans Murawski, Wilhelm Meyer: Geological dictionary. 12th edition. Spektrum Akademischer Verlag, 2010, p. 37, ISBN 978-3-8274-1810-4 .

See also

Individual evidence

  1. Fritz F. Steininger, Werner E. Piller (Ed.): Recommendations (guidelines) for handling the stratigraphic nomenclature. Courier Research Institute Senckenberg. Vol. 209, 1999 ( excerpt ).
  2. International Commission on Stratigraphy: Lithostratigraphic Units. International Stratigraphic Guide. 2nd edition, 1994.