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Basement[edit]

The dominant rocks of the basement are gneiss (ortho- and paragneisses, in the south also migmatites and diatexites, e. g. on the Schauinsland and Kandel). These gneisses were penetrated by a number of granitic bodies during the Carboniferous period. Among the bigger ones are the Triberg Granite and the Forbach Granite, the youngest is the Bärhalde Granite. In the south lies the zone of Badenweiler-Lenzkirch, in which Palaeozoic rocks have been preserved (volcanite and sedimentary rocks), which are interpreted as the intercalated remains of a microcontinental collision. Still further in the southeast (around Todtmoos) is a range of exotic inclusions: gabbro from Ehrsberg, serpentinites and pyroxenites near Todtmoos, norite nearHorbach), which are possibly the remnants of an accretionary wedge from a continental collision. Also noteworthy are the basins in the rotliegendes, for example the Schramberg or the Baden-Baden Basin, with, in places thick, quartz-porphyry and tuff plates (exposed, for example, on the rock massif of Battert near Baden-Baden). Thick rotliegendes rock, covered by bunter, also occurs in the north of the Dinkelberg block (several hundred metres thick in the Basel geothermal borehole). Even further to the southeast, under the Jura, lies the North Swiss Permocarboniferous Basin.