Bartonian

  (Redirected from Auversian)


The Bartonian is, in the ICS's geologic time scale, a stage or age in the middle Eocene epoch or series. The Bartonian age spans the time between 41.2 and 37.8 Ma. It is preceded by the Lutetian and is followed by the Priabonian age.[3]

Bartonian
41.2 – 37.71 Ma
Chronology
Key events in the Paleogene
-65 —
-60 —
-55 —
-50 —
-45 —
-40 —
-35 —
-30 —
-25 —
First Antarctic permanent ice-sheets[1]
An approximate timescale of key Paleogene events
Axis scale: millions of years ago
Formerly part ofTertiary Period/System
Etymology
Name formalityFormal
Usage Information
Celestial bodyEarth
Regional UsageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionNot formally defined
Lower boundary definition candidatesCalcareous nannofossil near LAD of the Haptophyte Reticulofenestra reticulata
Lower boundary GSSP candidate section(s)Contessa highway section, Gubbio, Central Apennines, Italy
Upper boundary definitionLAD of the large acarininids and the Foraminiferan Morozovelloides crassatus
Upper boundary GSSPAlano section, Piave river, Venetian Prealps, Belluno, Italy
45°54′51″N 11°55′05″E / 45.9141°N 11.9180°E / 45.9141; 11.9180
GSSP ratifiedFebruary 2020[2]

Stratigraphic definitionEdit

The Bartonian stage was introduced by Swiss stratigrapher Karl Mayer-Eymar in 1857. The name derives from the coastal village Barton-on-Sea (part of New Milton) in southern England.[citation needed] The Barton Group, a lithostratigraphic unit from the south English Hampshire Basin, 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.[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[4]), 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.

ReferencesEdit

FootnotesEdit

  1. ^ 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.2005.01.001.
  2. ^ 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. doi:10.18814/epiiugs/2020/020074. Retrieved 12 December 2020.
  3. ^ International Commission on Stratigraphy 2017
  4. ^ Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. Retrieved 15 July 2009.

LiteratureEdit

  • 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 linksEdit