Overburden

Overburden of the North American Platform in the Colorado Plateau, raised at about 2000 meters above sea level : Permian (below) to Jura (above)

In geology, an overburden is a rock complex that differs in its deformation style and degree of metamorphism from the geologically older basement . In the narrower sense, and specifically relating to the geology of Germany , the term includes unmetamorphic ^* and at most fractional tectonically deformed rock sequences (outdated: seam mountains ) that are always above the basement. The contact between the basement and the overburden is often at discordant angles .

In regions whose surface geology is determined by overburden in the narrower sense and which are also well above the erosion base (in Germany primarily the Thuringian Basin and the southern German layer basin ), typical stratiform landscapes can develop. There, in the area of ​​the more erosion-resistant layers, there are numerous outcrops in which these layers of the overburden, which are mostly composed of sedimentary rock , and less often of volcanic rock , can be studied.

^* Local contact metamorphosis due to ( sub ) volcanism excluded

Mineral deposits / mining

Loosely sandy overburden (in terms of mineral deposits) over the first Lusatian seam in the Welzow-Süd opencast mine ( Niederlausitz ). Both the sands and the lignite seam belong to the younger ( Cenozoic ) part of the overburden complex of northern and central Germany.

In deposit science, the rock area that is located between the deposit and the surface (see hanging wall ) is understood as the overburden . Both overburden and deposit can belong to an overburden complex in the geological sense. If the overburden of a deposit is relatively thin, open-cast mining is worthwhile . The removed overburden is then referred to as overburden .

literature

• Hans Murawski, Wilhelm Meyer: Geological dictionary. 10th edition. Enke Verlag, Stuttgart 1998 ISBN 3-432-84100-0

Individual evidence

1. ↑ Otto Lueger: Lexicon of all technology and its auxiliary sciences, Vol. 4. Stuttgart, Leipzig 1906, p. 92. ( HTML version of the entry for the keyword Flözgebirge on zeno.org )
2. ↑ Collective of authors: Lexicon of Geosciences , Volume I, Spektrum Akademischer Verlag, Heidelberg, Berlin 2000, ISBN 3-8274-0299-9 , p. 402