The Rotliegend, Rotliegend Group or Rotliegendes () is a lithostratigraphic unit (a sequence of rock strata) of latest

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

to Guadalupian (middle

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

) age that is found in the subsurface of large areas in western and central

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. The Rotliegend mainly consists of

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

layers. It is usually covered by the

Zechstein The Zechstein ( German either from ''mine stone'' or ''tough stone'') is a unit of sedimentary rock layers of Late Permian ( Lopingian) age located in the European Permian Basin which stretches from the east coast of England to northern Poland. T ...

and lies on top of regionally different formations of late

age. The name Rotliegend has in the past not only been used to address the rock strata themselves, but also the time span in which they were formed (in which case the Rotliegend was considered a series or subsystem of the Permian). This time span corresponds roughly with the length of the Cisuralian epoch.

Facies and formation

In large parts of Pangaea, the last phases of the Hercynian orogeny were still ongoing during the start of the Permian. At the same time local crustal extension formed intramontane basins such as the large Permian Basin which covered parts of present-day

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

, the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

, the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

and the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

. The early development of the basin went hand in hand with volcanism. Apart from these volcanic deposits the basin was filled by the

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

al products of the Hercynian mountains to the south: mostly sands and gravels deposited under an arid and warm climate.Ziegler (1990), p. 71

Stratigraphy

In the north of Germany and in the Netherlands, the Rotliegend is usually subdivided into two groups: a Lower Rotliegend Group (mostly volcanic rocks: tuffs and basaltic

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

s) and an Upper Rotliegend Group (

s and siltstones). During the formation of the lower group the basin was still small and the deposition was restricted to the centre of the basin in the southeastern North Sea and northern Germany, this group is very limited in thickness in the Dutch subsurface. The upper group has a larger arial distribution since the basin had grown wider. In Dutch lithostratigraphy, the Rotliegend lies on top of the late Carboniferous Limburg Group and below the Zechstein Group. The Upper Rotliegend Group is divided in the Silverpit Formation and Slochteren Formation, the last is an important

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

for

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...

s. The German Bentheim Sandstone, which crops out in the Münsterland, is part of the Slochteren Formation. The Rotliegend of northern Germany is continuous with that of the Netherlands. In other parts of Germany contemporaneous basins exist, such as the Saar-Nahe Basin, the Wetterau or the Saale Basin. The Rotliegend of these different intramontane basins is not easy to correlate and the lithostratigraphy of each basin has its own divisions (groups and formations).

Notes

Literature

*Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: ''A Geologic Time Scale 2004'', Cambridge University Press *Ziegler, P.A.; 1990 (2nd ed.): ''Geological Atlas of Western and Central Europe'', Shell Internationale Petroleum Maatschappij BV, . {{clr Carboniferous System of Europe Permian System of Europe Paleozoic Poland Carboniferous Germany Permian Germany