The Hanau-Seligenstadt Basin is a subbasin of 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 s ...

southeast of

Frankfurt am Main Frankfurt, officially Frankfurt am Main (; Hessian: , "Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its na ...

(Hesse, Bavaria, Germany).

Location

Panorama Untermainebene Rhein-Main-Tiefland

The Hanau-Seligenstadt Basin is located in the eastern part of the Lower Main lowlands. The river

Main Main may refer to: Geography * Main River (disambiguation) **Most commonly the Main (river) in Germany * Main, Iran, a village in Fars Province *"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries ...

crosses the basin between

Aschaffenburg Aschaffenburg (; South Franconian: ''Aschebersch'') is a town in northwest Bavaria, Germany. The town of Aschaffenburg is not part of the district of Aschaffenburg, but is its administrative seat. Aschaffenburg belonged to the Archbishopric ...

and

Offenbach am Main Offenbach am Main () is a List of cities and towns in Germany, city in Hesse, Germany, on the left bank of the river Main (river), Main. It borders Frankfurt and is part of the Frankfurt urban area and the larger Frankfurt Rhein-Main Regional Aut ...

. The largest cities of the area are

Hanau Hanau () is a town in the Main-Kinzig-Kreis, in Hesse, Germany. It is located 25 km east of Frankfurt, Frankfurt am Main and is part of the Frankfurt Rhine-Main, Frankfurt Rhine-Main Metropolitan Region. Its Hanau Hauptbahnhof, station is a ...

Seligenstadt Seligenstadt is a town in the Offenbach (district), Offenbach district in the ''Regierungsbezirk'' of Darmstadt (region), Darmstadt in Hesse, Germany. Seligenstadt is one of Germany's oldest towns and was already of great importance in Carolingian ...

and

Dieburg Dieburg () is a small town in southern Hesse, Germany. It was formerly the seat of the district ("Kreis") of Dieburg, but is now part of the district of Darmstadt-Dieburg. History The town of Dieburg was first named in 1492 in the tax books of the ...

Geologic setting

The Hanau-Seligenstadt Basin is a

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...

graben In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic contex ...

. As a subbasin of the Upper Rhine Graben it belongs to 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 ( ...

, a fracture zone crossing Europe from the North Sea to the Mediterranean. The Hanau-Seligenstadt Basin is separated from the Upper Rhine Graben to the west by a horst block. The

Spessart Spessart is a ''Mittelgebirge'', a range of low wooded mountains, in the States of Bavaria and Hesse in Germany. It is bordered by the Vogelsberg, Rhön and Odenwald. The highest elevation is the Geiersberg at 586 metres above sea level. Etymo ...

mountains form its eastern margin. To the south it is bounded by the

Odenwald The Odenwald () is a low mountain range in the German states of Hesse, Bavaria and Baden-Württemberg. Location The Odenwald is located between the Upper Rhine Plain with the Bergstraße and the ''Hessisches Ried'' (the northeastern section ...

mountains. Towards the north the graben margins converge. The basin sediments rest on top of the

Variscan 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'', comes f ...

basement and

Permian The Permian ( ) is a geologic period and 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 251.9 Mya. It is the last period of the Paleoz ...

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

rocks.

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

basin sediments reach more than 280 m in thickness. Marine,

limnic Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

and finally terrestrial

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

marl Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part o ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

s and

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

s with interbedded

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

layers dominate within the

and

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

. The

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

river deposits consist of sand,

gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

and

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...

, in Pliocene also

lignite Lignite, often referred to as brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat ...

. The recent landscape is formed by

river terrace Fluvial terraces are elongated terraces that flank the sides of floodplains and fluvial valleys all over the world. They consist of a relatively level strip of land, called a "tread", separated from either an adjacent floodplain, other fluvial te ...

Evolution

From the Triassic until the early

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

the later Hanau-Seligenstadt Basin was a non-depositional region. Subsidence started latest during the

(

Rupelian The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian ...

) about 30 million years ago during the evolution of the Upper Rhine Graben. The Upper Rhine Graben Sea and Upper Rhine Graben Lake also covered the Hanau-Seligenstadt Basin. Debris from the local highlands caused silting up and development of a river plain during the

. About 15 million years ago during the

Langhian The Langhian is, in the ICS geologic timescale, an age or stage in the middle Miocene Epoch/Series. It spans the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma (million years ago) during the Middle Miocene.GeoWhen (2007) The Langhian was a ...

volcanoes poured

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 moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

flows over parts of the area. Still during the Langhian, rivers started to

erode Erode () is a city in the Indian state of Tamil Nadu. Erode is the seventh largest urban agglomeration in the state, after Chennai, Coimbatore, Madurai, Tiruchirapalli, Tiruppur and Salem. It is also the administrative headquarters of the E ...

their former sediments. In the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Main Main may refer to: Geography * Main River (disambiguation) **Most commonly the Main (river) in Germany * Main, Iran, a village in Fars Province *"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries ...

river and its tributaries recommenced to deposit

and

. In lakes and swamps also

layers and

developed. The still relatively short river Main tapped the Upper Main in the early

. The resulting large river transported much sand and gravel into the Hanau-Seligenstadt Basin. During the Middle

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

rivers started once again to incise into their former sediments. The individual stages of the incision history are preserved as

Resources

In the Hanau-Seligenstadt Basin sand, gravel and clay are dug in many pits. Until the 1930s also lignite and until the 1980s Miocene basalts were mined. The sand and gravel deposits are yielding

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...

s exploited for water supply.

References

External links

*Lang, Stefan (2007): Die geologische Entwicklung der Hanau-Seligenstädter Senke (Hessen, Bayern).– Elektronische Publikationen Darmstadt (EPDA), 782, 97 S., 51 Abb., 5 Tab., Anhang. https://tuprints.ulb.tu-darmstadt.de/782/ * {{Authority control Geography of Bavaria Regions of Hesse Cenozoic rifts and grabens Upper Rhine