The Pliensbachian is an

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone or something has been alive or has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

of the

geologic timescale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronol ...

and

stage 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 * Sta ...

in the stratigraphic column. It is part of the Early or Lower Jurassic

Epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

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 spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago). The Pliensbachian is preceded by the

Sinemurian In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is ...

and followed by the

Toarcian The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ...

. The Pliensbachian ended with the

extinction event An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. I ...

called the

Toarcian turnover The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

. During the Pliensbachian, the middle part of the

Lias Lias may refer to: Geology * Lias Formation, a geologic formation in France *Lias Group, a lithostratigraphic unit in western Europe * Early Jurassic, an epoch People * Godfrey Lias, British author * Mohd Shamsudin Lias (born 1953), Malaysian ...

was deposited in Europe. The Pliensbachian is roughly coeval with the

Charmouthian The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago). The Plien ...

regional stage of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

Stratigraphic definitions

The Pliensbachian takes its name from the hamlet of Pliensbach in the community of

Zell unter Aichelberg Zell unter Aichelberg is a municipality in the district of Göppingen in Baden-Württemberg in southern Germany. Geographical location Between Stuttgart and Ulm, on the western edge of the district Göppingen, lies the municipality of Zell unter ...

in the

Swabian Alb The Swabian Jura (german: Schwäbische Alb , more rarely ), sometimes also named Swabian Alps in English, is a mountain range in Baden-Württemberg, Germany, extending from southwest to northeast and in width. It is named after the region of ...

, some 30 km east of

Stuttgart Stuttgart (; Swabian: ; ) is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley known as the ''Stuttgarter Kessel'' (Stuttgart Cauldron) and lies an hour from the ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. The name was introduced into scientific literature by German palaeontologist

Albert Oppel Carl Albert Oppel (19 December 1831 – 23 December 1865) was a German paleontologist. History He was born at Hohenheim in Württemberg, on 19 December 1831. He first went to the University of Tübingen, where he graduated with a Ph.D. i ...

in 1858. The base of the Pliensbachian is at the first appearances of the ammonite species '' Bifericeras donovani'' and

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

Apoderoceras ''Apoderoceras'' is an extinct genus of cephalopod belonging to the ammonite subclass. Biostratigraphic significance The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus ''Apoderoceras'' and of '' ...

'' and ''

Gleviceras ''Gleviceras'' is an ammonite genus (order Ammonitida) that lived during the Early Jurassic Period, found in Canada, Hungary, Mexico and the United Kingdom. ''Glevumites'' Buckman 1924, ''Guibaliceras'' Buckman 1918, ''Riparioceras'' Schindewo ...

''. The Wine Haven profile near

Robin Hood's Bay Robin Hood's Bay is a small Yorkshire coast fishery, fishing village and a bay located in the North York Moors National Park, south of Whitby and north of Scarborough, North Yorkshire, Scarborough on the coast of North Yorkshire, England. Ba ...

(

Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

) has been appointed as global reference profile for the base (

GSSP A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted b ...

).Meister ''et al.'' (2006) The top of the Pliensbachian (the base of the Toarcian Stage) is at the first appearance of ammonite genus '' Eodactylites''.

Biostratigraphy

The Pliensbachian contains five ammonite

biozone In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties of ...

s in the

boreal domain Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...

: *zone of '' Pleuroceras spinatum'' *zone of '' Amaltheus margaritatus'' *zone of '' Prodactylioceras davoei'' *zone of '' Tragophylloceras ibex'' *zone of '' Uptonia jamesoni'' In the Tethys domain, the Pliensbachian contains six biozones: *zone of '' Emaciaticeras emaciatum'' *zone of '' Arieticeras algovianum'' *zone of '' Fuciniceras lavinianum'' *zone of ''Prodactylioceras davoei'' *zone of ''Tragophylloceras ibex'' *zone of ''Uptonia jamesoni''

References

Notes

Literature

*; 2004: ''A Geologic Time Scale 2004'',

Cambridge University Press Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing hou ...

. *; 2002: ''The Lower Lias of Robin Hood's Bay, Yorkshire, and the work of Leslie Bairstow'', Bulletin of the Natural History Museum. Geology Series 58, p. 81–152, Cambridge University Press, The Natural History Museum,
abstract
*; 2006: ''The Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic), Wine Haven, Yorkshire, UK'', Episodes 29(2), pp. 93–106. *; 1856-1858: ''Die Juraformation Englands, Frankreichs und des südwestlichen Deutschlands: nach ihren einzelnen Gliedern engetheilt und verglichen'', 857 pp., Ebner & Seubert, Stuttgart.

External links

Lower Jurassic timescale
at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Lower Jurassic
at the website of Norges Network of offshore records of geology and stratigraphy {{Geological history, p, m *03 Geological ages