Earth:Priabonian

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Short description: Fourth and last Age of the Eocene Epoch
Priabonian
37.71 – 33.9 Ma
Chronology
Paleogene graphical timeline
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-65 —
-60 —
-55 —
-50 —
-45 —
-40 —
-35 —
-30 —
-25 —
First Antarctic permanent ice-sheets[1]
Subdivision of the Paleogene according to the ICS, as of 2021.[2]
Vertical axis scale: millions of years ago
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 definitionLAD of the large acarininids and the Foraminiferan Morozovelloides crassatus
Lower 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[3]
Upper boundary definitionLAD of Planktonic Foraminifers Hantkenina and Cribrohantkenina
Upper boundary GSSPMassignano quarry section, Massignano, Ancona, Italy
[ ⚑ ] 43°31′58″N 13°36′04″E / 43.5328°N 13.6011°E / 43.5328; 13.6011
GSSP ratified1992[4]

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 37.8 and 33.9 Ma. The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of the Oligocene.[5]

Stratigraphic definition

The Priabonian Stage was introduced in scientific literature by Ernest Munier-Chalmas and Albert de Lapparent in 1893. The stage is named after the small hamlet of Priabona in the community of Monte di Malo, in the Veneto region of northern Italy.

The base of the Priabonian Stage is at the first appearance of calcareous nannoplankton species Chiasmolithus oamaruensis (which forms the base of nanoplankton biozone NP18). An official GSSP was ratified in 2020, and was placed in the Alano di Piave section in Alano di Piave, Belluno, Italy.[3]

The top of the Priabonian Stage (the base of the Rupelian Stage and Oligocene Series) is at the extinction of foram genus Hantkenina.

Sometimes local rock strata cannot be correlated in sufficient detail with the ICS timescale, and stratigraphers often use regional timescales as alternatives to the ICS timescale. The Priabonian overlaps for example the upper Johannian and lowers Aldingan stages of the Australia n timescale or the upper Nanzian and lower Refugian stages of the California n timescale. Other regional stages which are more or less coeval with the Priabonian include the Jacksonian of the southeastern US and Runangan of New Zealand.

In biostratigraphy, the Priabonian Stage is coeval with the Chadronian North American Land Mammal Age, the Headonian European Land Mammal Mega Zone (in more detail: with the Mammal Paleogene zones 17A through 20[6]), parts of the Barrancan and Mustersan South American Land Mammal Ages and the Ulangochuian and Ergilian Asian Land Mammal Ages.

References

  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. doi:10.1016/j.gloplacha.2005.01.001. Bibcode2005GPC....47...51Z. 
  2. "International Chronostratigraphic Chart". International Commission on Stratigraphy. https://stratigraphy.org/icschart/ChronostratChart2020-01.pdf. 
  3. 3.0 3.1 Agnini, Claudia; Backman, Jan; Boscolo-Galazzo, Flavia; Condon, Daniel; Fornaciari, Eliana; Galeotti, Simone; Giusberti, Luca; Grandesso, Paolo et al. (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. 
  4. Silva, Isabella; Jenkins, D. (September 1993). "Decision on the Eocene-Oligocene boundary stratotype". Episodes 16 (3): 379–382. doi:10.18814/epiiugs/1993/v16i3/002. https://stratigraphy.org/gssps/files/rupelian.pdf. Retrieved 13 December 2020. 
  5. International Commission on Stratigraphy 2017
  6. Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. http://paleodb.org/cgi-bin/bridge.pl?action=processViewScale&scale_no=125. 

Literature

  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press .
  • Munier-Chalmas, E. & de Lapparent, A.; 1893: Note sur la nomenclature des terrains sédimentaires, Bulletin de la Société Géologique de France 3(21), p. 479-480. (in French)

External links