Fanglomerate

Fang lomerate at the base of the Middle Devonian ( Eifelium ), Kluckensteine near Vicht

A Fanglomerat ( Engl . Fan "fan", lat . Conglomerare "together accumulate" even arid boulder clay , occasionally: Schlammbrekzie ) is in arid formed regions clastic sedimentary rocks .

With regard to its structural characteristics , the rock stands between a conglomerate and a breccia , as it contains both slightly rounded and angular components ( clasts ) that can range from silt size to blocks with a diameter of 1.2 m. The structural features that are so characteristic of sedimentary rocks such as grading and stratification are almost completely missing, as is sorting according to grain size . The rock contains a lot of coarse material and only a small amount of fine-grained matrix as a binding agent.

Fang lomerate can be viewed as diagenetically solidified debris from one or more delivery areas ( hills , mountains and other high areas) in the vicinity, which explains its heterogeneous ( polymictic ) composition of different rock components. Due to the short transport routes, the components are hardly sorted or rounded. Fanglomerates are characteristic formations of alluvial fans in arid regions ( deserts and semi-deserts ). The transport of the constituents takes place through rare but abundant rainfall, heavy or jolting rain typical of the climate , which spread the rock material that had accumulated over the long dry periods in a fan-like manner in stratified floods .

Fossil fanglomerates are known, for example, from the Permian to Triassic Verrucano of the Alps . Other occurrences of such rocks can be found in the Rotliegend (and Zechstein ?) Of the Baden-Badener Trough in the northern Black Forest , in the Permian of the Oslo Graben or in the Permian Wadern layers of the Saar-Nahe Depression .

literature

Hans Füchtbauer: Sediments and sedimentary rocks . 4th edition. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 1988, ISBN 3-510-65138-3 , pp. 42 f .
Hans Murawski: Geological Dictionary . 8th edition. Enke, Stuttgart 1983, ISBN 3-432-84108-6 , pp. 63 .

Individual evidence

^ Matthias Lindinger: Sedimentological investigations of the Upper Palaeozoic Era west of Gaggenau and Gernsbach . In: Reports of the Natural Research Society in Freiburg im Breisgau . tape 74 , 1984, pp. 73–103 ( digitized version [PDF; 3.8 MB ]).

↑ T. McCann, C. Pascal, MJ Timmerman, P. Krzywiec, J. López-Gómez, A. Wetzel, CM Krawczyk, H. Rieke, J. Lamarche: Post-Variscan (end Carboniferous – Early Permian) basin evolution in Western and Central Europe. In: DG Gee, RA Stephenson (ed.): European Lithosphere Dynamics (= Geological Society of London, Memoirs. Volume 32). 2006, pp. 355–388, doi: 10.1144 / GSL.MEM.2006.032 (alternative full text access : University of Basel 2.6 MB)

↑ Kurosch Thuro: Geological and rock mechanics basics of mountain solution in tunnel (= Munich Geological books, series B . Band 18 ). 2002, p. 107 ff . ( Digital version - publication of a habilitation thesis, Faculty of Chemistry, TU Munich).

[1] Matthias Lindinger: Sedimentological investigations of the Upper Palaeozoic Era west of Gaggenau and Gernsbach . In: Reports of the Natural Research Society in Freiburg im Breisgau . tape 74 , 1984, pp. 73–103 ( digitized version [PDF; 3.8 MB ]).

[2] T. McCann, C. Pascal, MJ Timmerman, P. Krzywiec, J. López-Gómez, A. Wetzel, CM Krawczyk, H. Rieke, J. Lamarche: Post-Variscan (end Carboniferous – Early Permian) basin evolution in Western and Central Europe. In: DG Gee, RA Stephenson (ed.): European Lithosphere Dynamics (= Geological Society of London, Memoirs. Volume 32). 2006, pp. 355–388, doi: 10.1144 / GSL.MEM.2006.032 (alternative full text access : University of Basel 2.6 MB)

[3] Kurosch Thuro: Geological and rock mechanics basics of mountain solution in tunnel (= Munich Geological books, series B . Band 18 ). 2002, p. 107 ff . ( Digital version - publication of a habilitation thesis, Faculty of Chemistry, TU Munich).