Bartonian
| Bartonian | ||
|---|---|---|
| 41.2 – 37.71 Ma | ||
| Chronology | ||
Subdivision of the Paleogene according to the ICS, as of 2023.[2] Vertical axis scale: Millions of years ago | ||
45°54′51′′N 11°55′05′′E / 45.9141°N 11.9180°E / 45.9141; 11.9180
The Bartonian is, in the International Commission on Stratigraphy's (ICS) geologic time scale, a stage or age in the middle of the Eocene Epoch or Series. The Bartonian Age spans the time between 41.03 and 37.71 Ma. It is preceded by the Lutetian and is followed by the Priabonian Age.[4]
Stratigraphic definition
[edit ]The Bartonian Stage was introduced by Swiss stratigrapher Karl Mayer-Eymar in 1857. The name derives from the Barton Group, a lithostratigraphic unit from the south English Hampshire Basin, which in turn derived its name from the local coastal village Barton-on-Sea (part of New Milton) in southern England.[5] 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.[citation needed ]
The base of the Bartonian is at the first appearance of the calcareous nanoplankton species Reticulofenestra reticulata. In 2009, an official reference profile (GSSP) for the base of the Bartonian had not yet been established.[needs update ][citation needed ]
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 NP18).[citation needed ]
The Bartonian Stage overlaps part of the upper Robiacian European Land Mammal Mega Zone (it spans the Mammal Paleogene zone 16[6] ), the upper Uintan and Duchesnean North American Land Mammal Ages, part of the Divisaderan South American Land Mammal Age and is coeval with the Sharamururian Asian Land Mammal Age. [citation needed ]
The Auversian regional stage of France is coeval with the Bartonian and is therefore no longer used.
References
[edit ]Footnotes
[edit ]- ^ Zachos, J. C.; Kump, L. R. (2005). "Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene". Global and Planetary Change. 47 (1): 51–66. Bibcode:2005GPC....47...51Z. doi:10.1016/j.gloplacha.200501001.
- ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy . September 2023. Retrieved 16 December 2024.
- ^ Agnini, Claudia; Backman, Jan; Boscolo-Galazzo, Flavia; Condon, Daniel; Fornaciari, Eliana; Galeotti, Simone; Giusberti, Luca; Grandesso, Paolo; Lanci, Luca; Luciani, Valeria; Monechi, Simonetta; Muttoni, Giovanni; Pälike, Heiko; Pampaloni, Maria; Papazzoni, Cesare; Pearson, Paul; Pignatti, Johannes; Silva, Isabella; Raffi, Isabella; Rio, Domenico; Rook, Lorenzo; Sahy, Diana; Spofforth, David; Stefani, Cristina; Wade, Bridget (12 August 2020). "Proposal for the Global Boundary Stratotype Section and Point (GSSP) for the Priabonian Stage (Eocene) at the Alano section (Italy)". Episodes. 44 (2): 151–173. doi:10.18814/epiiugs/2020/020074 . hdl:2158/1209925 .
- ^ International Commission on Stratigraphy 2017
- ^ "Barton Group". British Geological Survey. UKRI. Retrieved 23 November 2023.
- ^ Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. Retrieved 15 July 2009.
Literature
[edit ]
- Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
- Mayer-Eymar, K.; 1857: Tableau synchronique des formations tertiaires d'Europe, 3rd ed., Zürich. (in French)
External links
[edit ]- GeoWhen Database – Bartonian
- Paleogene 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
