Lenzkircher Graben
The Lenzkircher Graben is a smaller rift valley in the Black Forest near Lenzkirch and the Titisee . It is part of the Bonndorfer Graben , a southeast-northwest to east-west trending tectonic rift system , the Badenweiler-Lenzkircher zone .
The entirety of the fractures, clods and faults is also referred to as the southern Black Forest main movement zone .
The faults near Lenzkirch open up porphyries , gneisses and greywacken des Kulm .
The original formation is assumed to be variskish . After a long period of rest it started moving again in the Eocene and Pleistocene , visible in the former volcanism in the Hegau . Light earthquakes point to the continuing activity of the earth's crust today ; the last major quake was in 1911.
A geological peculiarity is formed by the sedimentary rocks exposed as a result of the rift valley, which were largely transformed by metamorphosis . However, the fossil-rich layers of the Middle Carboniferous were not deposited here. In the schists of the Grauwacken from the upper Kulm goniatites were found near Schönau , and a ganoid fish , Elonichthys , from the lower Kulm near Lenzkirch .
See also
literature
- Rudolf Metz : Geological regional studies of the Hotzenwald , 1987 ISBN 3-7946-0174-2
- Hans Schneider, On young crust movements in the pre-Alpine landscape between the southern Rhine rift and Lake Constance , In: Mitteilungen der Naturforschenden Gesellschaft Schaffhausen , 1973 and 1975
- Friedrich Spiegelhalter , The tectonics in the uppermost part of the Bonndorfer Graben , inaugural dissertation, C. Winter 1912
- Serge von Bubnoff , The Hercynian Breaks in the Black Forest, their relationship to carbonic folding and their posthumidity , Stuttgart, Schweizerbart 1921 (Phil. Hab.-Schr.) Also as a special print in: New Yearbook for Mineralogy , Supplement Volume 45.
- Martin Georg Schäfer, The Devonian sediments of the southern Black Forest main movement zone ( Böllen- Lenzkirch) . Published as volume 8 of the work from the Geological-Paleontological Institute of the Technical University of Stuttgart , 1957