Priobonium

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system series step ≈ age ( mya )
higher higher higher younger
Paleogene Oligocene Chattium 23.03
⬍
28.1
Rupelium 28.1
⬍
33.9
Eocene Priobonium 33.9
⬍
38
Bartonium 38
⬍
41.3
lutetium 41.3
⬍
47.8
Ypresium 47.8
⬍
56
Paleocene Thanetium 56
⬍
59.2
Seelandium 59.2
⬍
61.6
Danium 61.6
⬍
66
deeper deeper deeper older

The Priabonium (mostly shortened to Priabon in German usage) is the highest chronostratigraphic stage of the Eocene ( Palaeogene ) in the history of the earth . Expressed in absolute numbers ( geochronologically ) this corresponds to the period from about 38 to about 33.9 million years. The stage follows the bartonium and is replaced by the rupelium , the lowest stage of the Oligocene .

Naming and history

The stage is named after the locality Priabona , which belongs to the municipality of Monte di Malo in the province of Vicenza ( Italy ). The stage and name were proposed by the two French geologists Ernest Munier-Chalmas and Albert de Lapparent in 1893.

Definition and GSSP

The lower limit of the level can be defined with the first appearance of the dinoflagellate Rhombodinium perforatum and is identical to the beginning of Chron C 17n.3n , slightly above the calcareous nannoplankton species Chiasmolithus oamaruensis (corresponds to the base of the nannoplankton zone NP18) for the first Times up. The end of the stage is determined by the extinction of the foraminifera genus Hantkenina and the taxon Turborotalia cerroazulensis cunialensis . A reference profile (GSSP = Global Stratotype Section and Point) for the Priabonium has not yet been established, but the pelagic profile in the Valle della Contessa (Central Italy) is a candidate .

Magnetostratigraphy

As already mentioned, the Priabonium begins magnetostratigraphically with Chron C 17n.1n . The stage then includes the Chrons C 16 , C 15 and C 13r (more precisely up to C 13r.86 ).

Biostratigraphy

Planktonic foraminifera

The Priabonium contains the planktonic foraminifera zones P 15 (upper two thirds), P 16 and P 17 . The taxon Turborotalia cerroazulensis cunialensis appears for the first time with P 16 ( FAD ); their extinction ( LAD ) marks the upper limit of P 17 and the end of the Priabons. The taxon Globigerinatheka semiinvoluta had appeared with P 15 before the beginning of the priabons.

Calcareous nannoplankton

The calcareous nannoplankton is represented by the zones NP 17 (uppermost section), NP 18 , NP 19 / NP 20 and NP 21 (lower third). The first appearance of Chiasmolithus oamaruensis defines the beginning of NP 18 , Isthmolithus recurvus the beginning of NP 19 . Discoaster barbadiensis disappears at the end of NP 20 .

Dinoflagellates

The Priabonium includes the greater part of the cyst zone D 12 , the beginning of which is marked by Rhombodinium perforatum and is identical to the lower limit of the Priabons. The dinoflagellate zone D 12 is divided into three sub-zones ( D 12a , D 12b and D 12c ). D 12b begins with the first appearance of Talassisphora fenestrata , D 12c with Talassisphora reticulata . Heteraulacacysta porosa disappears at the end of D 12a and Glaphyrocysta semitecta at the end of D 12b . The extinction of Areosphaeridium michoudii is identical to the beginning of Chron C 15 .

Land mammal biozones

The Nimravide Hoplophoneus from North America

The Priabonium includes the following land mammal biozones (Land Mammal Mega Zones), separated by continents:

The families Xiphodontidae and Amphimerycidae as well as the taxa Propalaeotherium (at the beginning of the Priabons), Quercygale , Isoptychus euzetensis and the Palaeotherium Lophiotherium as well as the three Palaeotherium species P. villerealense and P. curtum and P. medium disappear . For the first time the families of the Cricetidae and Castoridae appear as well as the taxa Isoptychus euzetensis and Entelodon as well as four species of Palaeotherium : P. magnum , P. villerealense , P. curtum and P. medium .

The families Nyctitheriidae , Cylindrodontidae , Oromerycidae (towards the end of Priabons) and the Plesiadapiformes (at the beginning of Priabons) extinct. The families of the Ursidae ( Parictis ) and the Entelodontidae (beginning of Ch. 1), the Nimravidae and the taxon Merycoidodon (beginning of Ch. 2) as well as the Cricetidae and Mustelidae (beginning of Ch. 3) appear for the first time.

Occurrence

In addition to the eponymous occurrence in northern Italy (deep marine area), the Priabonium occurs in the following sedimentation areas (each in order from hanging wall to lying):

literature

  • Felix M. Gradstein, Jim Ogg, Jim Smith, Alan Smith (Eds.): A Geologic timescale 2004. 3rd edition . Cambridge University Press, Cambridge et al. 2004, ISBN 0-521-78673-8 .
  • Ernest Munier-Chalmas, Albert de Lapparent: Note on the nomenclature of the terrains sédimentaires . In: Bulletin de la Societé Géologique de France. 3rd series . tape 21 , 1893, ISSN  0037-9409 , p. 479-480 .
  • Hans Murawski, Wilhelm Meyer: Geological dictionary. 10th revised and expanded edition . Enke Verlag, Stuttgart 1998, ISBN 3-432-84100-0 . ( Enke paperback ).

Individual evidence

  1. ^ Munier-Chalmas, E. & De Lapparent, A .: Note sur la nomenclature des terrains sédimentaires . Bulletin de la Société Géologique de France, 3ème série. tape 21 , 1893, pp. 438-493 .

Web links

  • German Stratigraphic Commission, Manfred Menning (Hrsg.): Stratigraphische Tisch von Deutschland 2002 . Potsdam 2002, ISBN 3-00-010197-7 (1 sheet, Stratigraphie.de [PDF; 6.6 MB ]).
  • Commission for the paleontological and stratigraphic research of Austria of the Austrian Academy of Sciences (Ed.): The Stratigraphic Table of Austria (sedimentary layer sequences) - [1] (large; PDF; 381 kB)
  • International Chronostratigraphic Chart 2012 (PDF)