The Pliensbachian is an

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone has been alive or something 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 geochron ...

and

stage Stage, stages, or staging may refer to: Arts and media 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 Brit ...

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 b ...

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 spans the time between 192.9 ±0.3 Ma and 184.2 ±0.3 Ma (million years ago). The Pliensbachian is preceded by the

Sinemurian In the geologic timescale, the Sinemurian is an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between 199.5 ±0.3 annu ...

and followed by the

Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...

. 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 fall in the diversity and abundance of multicellular organisms. It occ ...

called the

Toarcian turnover The Toarcian extinction event, also called the Pliensbachian-Toarcian extinction event, the Early Toarcian mass extinction, the Early Toarcian palaeoenvironmental crisis, or the Jenkyns Event, was an extinction event that occurred during the early ...

. During the Pliensbachian, the middle part of the Lias 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 192.9 ±0.3 Ma and 184.2 ±0.3 Ma (million years ago). The Pliens ...

regional stage of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Stratigraphic definitions

The Pliensbachian takes its name from the hamlet of

Pliensbach Pliensbach is a hamlet in the municipality of Zell unter Aichelberg in the district of Göppingen in central Baden-Württemberg. History In 1452, Pliensbach came under the possession of Württemberg. In September 1519, during the conflicts bet ...

in the community of

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

in the

Swabian Alb The Swabian Jura ( , 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 Swabia. It is part of th ...

, some 30 km east of

Stuttgart Stuttgart (; ; Swabian German, Swabian: ; Alemannic German, Alemannic: ; Italian language, Italian: ; ) is the capital city, capital and List of cities in Baden-Württemberg by population, largest city of the States of Germany, German state of ...

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 ...

. 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 (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

Apoderoceras ''Apoderoceras'' is an extinct genus of cephalopod belonging to the ammonite subclass. Ammonites (Apoderoceras) were predatory mollusks that resembled a squid with a shell. These cephalopods had eyes, tentacles, and spiral shells. They are more ...

'' 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'' Schindewol ...

''. The Wine Haven profile near

Robin Hood's Bay Robin Hood's Bay is a village in North Yorkshire, England. It is south of Whitby and north of Scarborough on the Yorkshire Coast. It is an ancient chapelry of Fylingdales in the wapentake of Whitby Strand. It is on the Cleveland Way nati ...

(

Yorkshire Yorkshire ( ) is an area of Northern England which was History of Yorkshire, historically a county. Despite no longer being used for administration, Yorkshire retains a strong regional identity. The county was named after its county town, the ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

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

GSSP A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. ...

).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 taxon, taxa, as opposed to a Lithostratigraphy, lithostratigraphic unit which is defined by the ...

s in the boreal domain: *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 was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessme ...

. *; 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