The Bonndorf Graben (german: Bonndorfer Graben) is a southeast-northwest to east-west striking, tectonic graben system on the eastern edge of the

Black Forest The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is t ...

and in the Baar between Bonndorf im Schwarzwald (in the south) and Donaueschingen (in the north). The upper reaches of the Wutach flow through it. Formed during Variscan mountain building (in the Palaeozoic), the graben was reactivated in the

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

, when the basement and

platform Platform may refer to: Technology * Computing platform, a framework on which applications may be run * Platform game, a genre of video games * Car platform, a set of components shared by several vehicle models * Weapons platform, a system or ...

being created. The Bonndorf Graben continues through the Black Forest as the Lenzkirch Graben (''Lenzkircher Graben'') near Lenzkirch, the Höllental valley and the Freiburg Bay running up to the

Upper Rhine Graben The Upper Rhine Plain, Rhine Rift Valley or Upper Rhine Graben (German: ''Oberrheinische Tiefebene'', ''Oberrheinisches Tiefland'' or ''Oberrheingraben'', French: ''Vallée du Rhin'') is a major rift, about and on average , between Basel in the so ...

at Kaiserstuhl. It then heads east via Blumberg, here visible at the Riedöschinger Travertin and the Blauer Stein, in the direction of

Engen Engen (延元) was a Japanese era of the Southern Court during the Era of Northern and Southern Courts after Kenmu and before Kōkoku, lasting from February 1336 to April 1340.Nussbaum, Louis-Frédéric. (2005). "''Engen''" i ''Japan encyclop ...

in the

Hegau The Hegau is an extinct volcanic landscape in southern Germany extending around the industrial city of Singen (Hohentwiel), between Lake Constance in the east, the Rhine River in the south, the Danube River in the north and the Randen (mountain r ...

with the volcanic formations of

Hohenstoffeln Hohenstoffeln is a mountain of Baden-Württemberg, Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous m ...

, Hohenkrähen,

Hohentwiel Hohentwiel is an extinct volcano in the Hegau region of Baden-Württemberg in southern Germany The mountain is west of the city of Singen and 20 miles (30 km) from Lake Constance. Hohentwiel began forming, along with the chain of vol ...

, Höwenegg, Hohenhewen and Neuhewen, Mägdeberg, Hohenkrähen, Staufen and Rosenegg to Lake Constance. Defined by the trough of the Bonndorf Graben, the Jurassic hills of the Swabian Jura and the older strata of the platform (

bunter sandstone The Buntsandstein (German for ''coloured'' or ''colourful sandstone'') or Bunter sandstone is a lithostratigraphic and allostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Buntsands ...

muschelkalk The Muschelkalk (German for "shell-bearing limestone"; french: calcaire coquillier) is a sequence of sedimentary rock, sedimentary rock strata (a lithostratigraphy, lithostratigraphic unit) in the geology of central and western Europe. It has a Mid ...

keuper The Keuper is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Keuper consists of dolomite, shales or claystones and evaporites that were deposited during the Middle and Late T ...

) rise here the west.

References

Literature

* Friedrich Spiegelhalter, ''Die Tektonik im obersten Teil des Bonndorfer Grabens'', Inaugural-Dissertation, C. Winter 1912 * Serge von Bubnoff, ''Die hercynischen Brüche im Schwarzwald, ihre Beziehung zur carbonischen Faltung und ihre Posthumität'', Stuttgart, Schweizerbart, 1921 (Phil. Hab.-Schr.) also as a special edition in: ''Neues Jahrbuch für Mineralogie'', appendix or attachment to Volume 45. * Hans Schneider, ''Über junge Krustenbewegungen in der voralpinen Landschaft zwischen dem südlichen Rheingraben und dem Bodensee'', In: ''Mitteilungen der Naturforschende Gesellschaft Schaffhausen'', 1973 and 1975 * Martin Georg Schäfer, ''Die devonischen Sedimente der Südschwarzwälder Hauptbewegungszone ( Böllen-Lenzkirch)''. Appears as Volume 8 of ''Arbeiten aus dem Geologisch-Paläontologisches Institut der Technischen Hochschule Stuttgart'', 1957 * Rudolf Metz: ''Geologische Landeskunde des Hotzenwaldes'', 1987. {{coord missing, Baden-Württemberg Regions of Baden-Württemberg Breisgau-Hochschwarzwald South German Scarplands Plate tectonics