The Buntsandstein (German for ''coloured'' or ''colourful sandstone'') or Bunter sandstone is a

lithostratigraphic Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology. In general, strata are primarily igneous ...

and allostratigraphic unit (a sequence of

rock strata In geology and related fields, a stratum (: strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ...

) in the subsurface of large parts of west and central Europe. The Buntsandstein predominantly 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 of the

Lower Triassic The Early Triassic is the first of three epoch (geology), epochs of the Triassic Period (geology), Period of the geologic timescale. It spans the time between 251.9 annum, Ma and Ma (million years ago). Rocks from this epoch are collectively kno ...

series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used i ...

and is one of three characteristic Triassic units, together with the

Muschelkalk The Muschelkalk (German for "shell-bearing limestone"; ) is a sequence of sedimentary rock, sedimentary rock strata (a lithostratigraphy, lithostratigraphic unit) in the geology of central and western Europe. It has a Middle Triassic (240 to 230 m ...

and

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 Lat ...

that form the Germanic Trias Supergroup. The Buntsandstein is similar in age,

facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with distinctive characteristics. The characteristics can be any observable attribute of rocks (such as their overall appearance, composition, or con ...

and

lithology The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lit ...

with the Bunter of the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

. It is normally lying on top of the

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 ...

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 below the Muschelkalk. In the past the name Buntsandstein was in Europe also used in a chronostratigraphic sense, as a subdivision of the Triassic system. Among reasons to abandon this use was the discovery that its base lies actually in the latest Permian.

Origin

The Buntsandstein was deposited in the Germanic Basin, a large

sedimentary basin Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock They form when long-term subsidence ...

that was the successor of the smaller Permian Basin and spread across present day

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 ...

, Germany,

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 southern regions of 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 ...

and

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 ...

, 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 ...

and south England. In the late Permian this region had an

arid climate The desert climate or arid climate (in the Köppen climate classification ''BWh'' and ''BWk'') is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert ...

and it was covered by inland seas which deposited the Zechstein

evaporite An evaporite () is a water- soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as oce ...

s. At the end of the Permian a connection with the

Paleo-Tethys Ocean The Paleo-Tethys or Palaeo-Tethys Ocean was an ocean located along the northern margin of the paleocontinent Gondwana that started to open during the Middle Cambrian, grew throughout the Paleozoic, and finally closed during the Late Triassic; ex ...

to the south was formed in present-day southeast Poland, causing sea water to flow in periodically. This caused the inflow of more

clastic Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks by ...

material, which was deposited in the form of large

alluvial fan An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to Semi-arid climate, semiar ...

s. The same process happened in the Triassic for the Basque-Cantabrian Basin, in the axis of the future

Pyrenees The Pyrenees are a mountain range straddling the border of France and Spain. They extend nearly from their union with the Cantabrian Mountains to Cap de Creus on the Mediterranean coast, reaching a maximum elevation of at the peak of Aneto. ...

. Deposition took place in an arid,

continent A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...

al environment ( playa facies), so that there was little

chemical weathering Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs ''in situ'' (on-site, with little or no movem ...

. Therefore, the Buntsandstein deposits are typical

red beds Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain t ...

, mainly sandstones and conglomerates with little

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

. The late

Anisian In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...

saw a major rise of the global ( eustatic) sea level. A tropical sea filled the Germanic Basin then, stopping the deposition of the Buntsandstein and marking the beginning of the deposition of the Muschelkalk.

Stratigraphy

The Buntsandstein belongs to the

Changhsingian In the geologic time scale, the Changhsingian or Changxingian is the latest age or uppermost stage of the Permian. It is also the upper or latest of two subdivisions of the Lopingian Epoch or Series. The Changhsingian lasted from to 251.9 Ma a ...

to Anisian stages, meaning it is between 252 and 246 million years old.Manfred Menning, Reinhard Gast, Hans Hagdorn, Karl-Christian Käding, Theo Simon, Michael Szurlies und Edgar Nitsch: Zeitskala für Perm und Trias in der Stratigraphischen Tabelle von Deutschland 2002, zyklostratigraphische Kalibrierung der höheren Dyas und Germanischen Trias und das Alter der Stufen Roadium bis Rhaetium 2005. Newsletters on Stratigraphy, 41(1–3): 173–210, Stuttgart 2005 ISSN 0078-0421 In German lithostratigraphy, it is seen as a group, in the Netherlands and North Sea the name has no official status (though that does not keep geologists from using it). In the official Dutch lithostratigraphy, the Buntsandstein is divided into the

Lower Lower may refer to: * ''Lower'' (album), 2025 album by Benjamin Booker *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is sit ...

and Upper Germanic Trias Groups. The British Bunter Formation is basically a continuation of the same unit. In Germany the Buntsandstein is subdivided into three subgroups with seven formations (from top to base): Upper Buntsandstein * Röt Formation or Fährtensandstein Middle Buntsandstein * Solling Formation * Hardegsen Formation * Detfurth Formation * Volpriehausen Formation Lower Buntsandstein * Bernburg Formation * Calvörde Formation All of these are reasonably good reservoir rocks for oil and gas. In the Dutch subdivision, the upper two formations are part of the Upper Germanic Trias and the others part of the Lower Germanic Trias.

Natural monuments

Bunter sandstone often forms spectacular rock formations as a result of weathering: including isolated rocks several tens of metres high. Most of them are designated

natural monument A natural monument is a natural or cultural feature of outstanding or unique value because of its inherent rarity, representative of aesthetic qualities, or cultural significance. They can be natural geological and geographical features such as w ...

s, for example, the Devil's Table near Hinterweidenthal. In the Palatinate, near Eppenbrunn, are the so-called '' Altschlossfelsen'' ("Old Castle Rocks"). The massif has a length of around 1.5 km and a height of up to 25 metres, easily the largest bunter sandstone massif in the Palatinate. On the island of

Heligoland Heligoland (; , ; Heligolandic Frisian: , , Mooring Frisian: , ) is a small archipelago in the North Sea. The islands were historically possessions of Denmark, then became possessions of the United Kingdom from 1807 to 1890. Since 1890, the ...

, the 47-metre-high '' Lange Anna'' ("Tall Anna"), is the best-known landmark on the island and was declared a natural monument in 1969.

Fossils

The Buntsandstein contains a few small saurians, tracks like '' Chirotherium'' and plant remnants.

Notes

References

* * *

External links

*(In Dutch
Structural description of the Dutch Triassic, including stratigraphic diagrams
website of TNO. {{Authority control Triassic System of Europe Lithostratigraphy Geology of Germany Lithostratigraphy of Germany Stratigraphy of Europe