The Bartonian is, in the

International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, strati ...

's (ICS)

geologic time scale 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 geochro ...

, a

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 ...

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 ...

in the middle of the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

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 ...

. The Bartonian Age spans the time between . It is preceded by the

Lutetian The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...

and is followed by the

Priabonian The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage ...

Age.

Stratigraphic definition

The Bartonian Stage was introduced by

Swiss Swiss most commonly refers to: * the adjectival form of Switzerland * Swiss people Swiss may also refer to: Places * Swiss, Missouri * Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss Café, an old café located ...

stratigrapher

Karl Mayer-Eymar Karl David Wilhelm Mayer-Eymar (29 July 1826 – 25 February 1907) was a Franco-Swiss paleontologist and geologist known for his work on classifying the stratigraphy of the Tertiary into 12 stages. He was born Karl Mayer but added the anagram Eyma ...

in 1857. The name derives from the

Barton Group The Barton Group is a geological group found in the Hampshire Basin of Southern England. It ranges in age from Lutetian (Lower Eocene) to Priabonian (Upper Eocene). It is exposed on the coast in southern Hampshire and in the northern part of the I ...

, 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 ...

unit from the south English

Hampshire Basin The Hampshire Basin is a geological basin of Palaeogene age in southern England, underlying parts of Hampshire, the Isle of Wight, Dorset, and Sussex. Like the London Basin to the northeast, it is filled with sands and clays of Paleocene and ...

, which in turn derived its name from the local coastal village

Barton-on-Sea Barton on Sea (often hyphenated as Barton-on-Sea) is a cliff-top village in Hampshire, England close to the town of New Milton to the north. Barton lies within the civil parish of New Milton. As a settlement, Barton has a history dating back to ...

(part of

New Milton New Milton is a market town and civil parish in the New Forest District, New Forest district, in southwest Hampshire, England. To the north is in the New Forest and to the south the coast at Barton-on-Sea. The town is equidistant between Lymi ...

) in southern England. The distinction between

group A group is a number of persons or things that are located, gathered, or classed together. Groups of people * Cultural group, a group whose members share the same cultural identity * Ethnic group, a group whose members share the same ethnic iden ...

and stage was made in the second part of the 20th century, when stratigraphers saw the need to distinguish between litho- and

chronostratigraphy Chronostratigraphy is the branch of stratigraphy that studies the ages of rock strata in relation to time. The ultimate aim of chronostratigraphy is to arrange the sequence of deposition and the time of deposition of all rocks within a geological ...

. The base of the Bartonian is at the first appearance of the calcareous nanoplankton species ''Reticulofenestra reticulata''. In 2009, an official reference profile (

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. ...

) for the base of the Bartonian had not yet been established. The top of the Bartonian Stage (the base of the Priabonian) is at the first appearance of calcareous nanoplankton species ''Chiasmolithus oamaruensis'' (which forms the base of nanoplankton

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 ...

NP18). The Bartonian Stage overlaps part of the upper Robiacian

European Land Mammal Mega Zone The European Land Mammal Mega Zones (abbreviation: ELMMZ, more commonly known as European land mammal ages or ELMA) are zones in rock layers that have a specific assemblage of fossils ( biozones) based on occurrences of fossil assemblages of Europ ...

(it spans the

Mammal Paleogene zone The Mammal Paleogene zones or MP zones are a system of biostratigraphic zones in the stratigraphic record used to correlate mammal-bearing fossil localities of the Paleogene period of Europe. It consists of thirty consecutive zones (numbered MP 1 ...

16), the upper

Uintan The Uintan North American Stage is the North American faunal stage, typically set from 46,200,000 to 42,000,000 years before present lasting 4.2 million years. The Uintan Stage is a key part of the North American land mammal age, North American Lan ...

and Duchesnean

North American Land Mammal Ages The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when ref ...

, part of the

Divisaderan The Divisaderan age is a South American land mammal age, covering a period of geologic time (42.0–36.0 Mya (unit), Ma) within the Middle Eocene, Middle and Late Eocene epochs of the Paleogene. It follows the Mustersan age and is followed by the T ...

South American Land Mammal Age The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as age ...

and is coeval with the Sharamururian

Asian Land Mammal Age The Asian land mammal ages, acronym ALMA, establish a geologic timescale for prehistoric Asian fauna beginning 58.7 Mya during the Paleogene and continuing through to the Miocene ( Aquitanian) (23.03 Ma). These periods are referred to as ages, sta ...

. The Auversian regional stage of France is coeval with the Bartonian and is therefore no longer used.

References

Footnotes

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 ...

. *; 1857: ''Tableau synchronique des formations tertiaires d'Europe'', 3rd ed., Zürich.

External links

GeoWhen Database – BartonianPaleogene timescale
at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Paleogene
at the website of Norges Network of offshore records of geology and stratigraphy {{Geological history, p, c Eocene geochronology Geological ages