The Eger Graben (much less commonly called the Ohre or Ohře Graben; cs, Oherský rift, german: Egergraben) is a geological structure in the

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

. It runs southwards, parallel to the Ore Mountains and its formation is linked with that of the mountain range.

Topography

The

Ohře The Ohře () or, slightly less commonly in English sources, the Eger (, Czech also: ''Oharka'' or ''Ohara'', Celtic: ''Agara'', pl, Ohrza), is a 316 km river in Germany (50 km) and the Czech Republic (266 km), left tributary of ...

(equally commonly known in English by its German name ''Eger'', hence the name of the trough) flows through the Eger Graben and separates the Ore Mountains from the

Slavkov Forest The Slavkov Forest ( cs, Slavkovský les), also called the Emperor's Forest
at www.sachsen.de. Retrieved 14 Nov 2016. (german: Ka ...

and the

Doupov Mountains Doupov Mountains ( cs, Doupovské hory, german: Duppauer Gebirge) is a cenozoic volcanic mountain range with the typical structure of stratovolcano. The centre of the stratovolcano was in the place of a former town of Doupov. The highest mounta ...

. The trench continues to the northeast along the valley of the

Bílina Bílina (; german: Bilin) is a town in Teplice District in the Ústí nad Labem Region of the Czech Republic. It has about 14,000 inhabitants. It is known for its spas and as a source of the strongly mineralized water, Bílinská kyselka. The to ...

and later, as the

North Bohemian Basin The Most Basin (also known as North Bohemian Basin; cs, Mostecká pánev, german: Nordböhmisches Becken) is a tectonic depression and geomorphological mesoregion of the Czech Republic. It is named after the city of Most. It forms the southwes ...

, separates the Ore Mountains from the Bohemian Central Mountains, where the River Ohře leaves the graben and flows into the Elbe south of the Bohemian Mountains.

Geology

The Eger Graben is part of the

European Cenozoic Rift System The European Cenozoic Rift System (ECRIS) is a long system of rifts formed in the foreland of the Alps as the lithosphere responded to the effects of the Alpine and Pyrenean orogenies. The system began to form during the Late Eocene and parts ( ...

and was created geologically on the same principle as the

Rhine Rift Valley 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 ...

. It was formed by the almost complete erosion of the

Variscan Mountains The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Variscan'', come ...

and sits on a

fault-block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relat ...

caused by the horizontal pressure of the

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

n continental plate. This block dropped, however, in contrast to the surrounding area. The Ore Mountains are fault-block mountains which rise very gently in Germany, but drop very steeply into the Eger Graben. The trench thus follows the main fault line of the Ore Mountains. Researchers believe that a new volcano is in the process of forming and hope to be able to drill holes in the area to better study what they believe is an awakening volcano.''Sachsen: Forscher entdecken erwachenden Vulkan nach Erdbeben''
at focus.de. Retrieved 18 December 2021.

References

Sources

P. De`zes*, S.M. Schmid, P.A. Ziegler (2004) ''Evolution of the European Cenozoic Rift System: interaction of the Alpine and Pyrenean orogens with their foreland lithosphere''Peter A. Ziegler (1990) ''Geological atlas of Western and Central Europe'', Volume 2
{{Authority control Geography of the Czech Republic Cenozoic rifts and grabens