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 igneou ...

and allostratigraphic unit (a sequence of rock strata) in the

subsurface In geology, bedrock is solid rock that lies under loose material (regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bedr ...

of large parts of west and central Europe. The Buntsandstein predominantly consists of sandstone layers of the Lower Triassic

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 in ...

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

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

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 The Germanic Trias Supergroup (german: Germanische Trias-Supergruppe) is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of western and central Europe (north of the Alps) and the North Sea. Almost all of the ...

Supergroup. The Buntsandstein is similar in age, facies 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 a group of islands in the 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 and Outer Hebrides, the Northern Isles, ...

. It is normally lying on top of the Permian

Zechstein The Zechstein ( German either from ''mine stone'' or ''tough stone'') is a unit of sedimentary rock layers of Middle to Late Permian (Guadalupian to Lopingian) age located in the European Permian Basin which stretches from the east coast of Engla ...

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 that was the successor of the smaller Permian Basin and spread across present day Poland, Germany, Denmark, the southern regions of the North Sea and

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

, the Netherlands 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 ocean ...

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; exi ...

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 ...

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 semiarid climates, but a ...

s. Deposition took place in an arid,

continent A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven ...

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, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), ...

. 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 th ...

, 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. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay parti ...

. The late Anisian saw a major rise of the global (

eustatic Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

) 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 251.902 mi ...

to Anisian

stages Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * St ...

, 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 (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 situated about five miles south west of Dursley, eigh ...

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 The Röt Formation or Rötton Formation (German for Röt Shale), or Upper Buntsandstein, is a geologic formation of the Buntsandstein in Germany. It preserves fossils dating back to the Middle Triassic Epoch (Anisian or Aegean or Bithynian in th ...

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 natural/cultural feature of outstanding or unique value because of its inherent rarity, representative of aesthetic qualities or cultural significance. Under World Commission on Protected Areas guidelines, nat ...

s, for example, the Devil's Table near

Hinterweidenthal Hinterweidenthal is a municipality in Südwestpfalz district, in Rhineland-Palatinate Rhineland-Palatinate ( , ; german: link=no, Rheinland-Pfalz ; lb, Rheinland-Pfalz ; pfl, Rhoilond-Palz) is a western state of Germany. It covers and h ...

. In the Palatinate, near

Eppenbrunn Eppenbrunn is a municipality in Südwestpfalz district, in Rhineland-Palatinate, western Germany and belongs to the municipal association Pirmasens-Land. Within the municipality is the 1.5 km long bunter sandstone The Buntsandstein (Germ ...

, 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 (; german: Helgoland, ; Heligolandic Frisian: , , Mooring Frisian: , da, Helgoland) is a small archipelago in the North Sea. A part of the German state of Schleswig-Holstein since 1890, the islands were historically possession ...

, the 47-metre-high ''

Lange Anna Lange Anna ("Tall Anna"), is a high sea stack of Buntsandstein in the North Sea island of Heligoland, Germany. Its local name is ''Nathurn Stak'' ("Northern Stack").Maren Lindstaedt, Thomas Kersten: Ein virtueller Klon für Helgolands Lange Ann ...

'' ("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 ''Chirotherium'', also known as ''Cheirotherium'' (‘hand-beast’), is a Triassic trace fossil consisting of five-fingered (pentadactyle) footprints and whole tracks. These look, by coincidence, remarkably like the hands of apes and bears, with ...

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