The Bartonian is, in the

ICS ICS may refer to: Computing * Image Cytometry Standard, a digital multidimensional image file format used in life sciences microscopy * Industrial control system, computer systems and networks used to control industrial plants and infrastructu ...

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 geoch ...

, a stage or age in the middle

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

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 ...

or Series. 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.International Commission on Stratigraphy 2017
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Stratigraphic definition

The Bartonian Stage was introduced by

Swiss Swiss may refer to: * the adjectival form of Switzerland * Swiss people Places * Swiss, Missouri *Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss-system tournament, in various games and sports *Swiss Internati ...

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 coastal village

Barton-on-Sea Barton on Sea (often hyphenated as Barton-on-Sea) is a cliff-top village in Hampshire, England with close connections, physical, governmental and commercial, to the inland town, New Milton which is its civil parish to the north. As a settlement ...

(part of

New Milton New Milton is a market town 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 Lymington and Christchurch, 6 miles (10 km) away. History N ...

) in southern England. 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 ...

, is of Bartonian age. The distinction between group 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 geologica ...

. The base of the Bartonian is at the first appearance of the calcareous

nanoplankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...

species ''Reticulofenestra reticulata''. In 2009, an official reference profile (

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 ...

) 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

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 taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties ...

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 16), the upper

Uintan The Uintan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna b ...

and

Duchesnean The Duchesnean North American Stage on the geologic timescale is a North American Land Mammal Age (NALMA), with an age from 42 to 38 million years BP, representing . It falls within the Eocene epoch. The Duchesnean is preceded by the Uintan and f ...

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 re ...

, part of the Divisaderan

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

Auversian The Bartonian is, in the International Commission on Stratigraphy, ICS's geologic time scale, a stage (stratigraphy), stage or age (geology), age in the middle Eocene epoch (geology), Epoch or series (stratigraphy), Series. The Bartonian Age sp ...

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 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 in the world. It is also the King's Printer. Cambr ...

. *; 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