Warehouse aisle

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Salisbury Crags in Edinburgh , Scotland , a warehouse corridor partially exposed during the Ice Age
A sill (light rock) cut in a former open-cast gold mine, Nevada, USA

A storage corridor or sill is a rock body made of igneous rock or, less often, sedimentary rock (mostly sandstone ) that has penetrated a rock parallel to the layers . In contrast to the storage corridor, Dyke (also Dike ) refers to a rock corridor that cuts or crosses the surrounding rock (vertical).

Characteristics of a warehouse aisle

The boundaries of a dike are always parallel to the stratification , and therefore, at first glance, dykes can be confused with volcanic lava flows , which in most cases are also parallel to the stratification due to their deposition on the earth's surface. However, there are several distinguishing features:

  • Both at the base and at the top of the storage corridor , the adjacent rock shows changes due to the high temperature of the penetrating magma ( contact metamorphosis , fritting ); this is only the case at the bottom with lava flows
  • Storage corridors do not have any degassing structures like former gas cavities
  • Lava flows often show signs of weathering or soil formation on their upper side , which are overlaid by younger layers; this is never the case with storage corridors
  • the adjacent rock may have been partially melted.

Since storage corridors cool and solidify very slowly depending on their thickness , they often show signs of gravitational differentiation . Ore minerals and other minerals formed early on sink to the bottom of the storage corridor , where they accumulate , which often form deposits of valuable ores ( layered intrusions ).

Occurrence

Examples of storage corridors or storage corridor -like geological bodies are the Precambrian Duluth Gabbro Complex or the Stillwater Complex in southern Montana . In Scotland , a warehouse corridor forms the Salisbury Crags in Edinburgh . Numerous small-scale storage corridors are known in Germany from the Lahn-Dill area in the Rhenish Slate Mountains , others can be found in the Vulkaneifel or in the Siebengebirge ( Weilberg ).

literature

  • Myron G. Best: Igneous and Metamorphic Petrology . WH Freemann & Company, San Francisco 1982, ISBN 0-7167-1335-7 .
  • Hans Murawski, Wilhelm Meyer: Geological dictionary . 11th edition. Elsevier / Spektrum, Heidelberg 2004, ISBN 3-8274-1445-8 .