Valanginium
system | series | step | ≈ age ( mya ) |
---|---|---|---|
higher | higher | higher | younger |
chalk | Upper Chalk | Maastrichtium | 66 ⬍ 72 |
Campanium | 72 ⬍ 83.6 |
||
Santonium | 83.6 ⬍ 86.3 |
||
Coniacium | 86.3 ⬍ 89.7 |
||
Turonium | 89.7 ⬍ 93.9 |
||
Cenomanium | 93.9 ⬍ 100.5 |
||
Lower Cretaceous | Albium | 100.5 ⬍ 112.9 |
|
Aptium | 112.9 ⬍ 126.3 |
||
Barremium | 126.3 ⬍ 130.7 |
||
Skin rivium | 130.7 ⬍ 133.9 |
||
Valanginium | 133.9 ⬍ 139.3 |
||
Berriasium | 139.3 ⬍ 145 |
||
deeper | deeper | deeper | older |
The Valanginium (in German often shortened to Valangin ) is a chronostratigraphic level of the Lower Cretaceous in the history of the earth . Geochronologically, it covers the period from approximately 139.3 to approximately 133.9 million years. The Valanginium follows the Berriasium and is replaced by the Hauterivium .
Naming and history
The original type locality is in the Seyon Gorge near Valangin in Switzerland ; the stage is named after this place. The stage and name were introduced by Édouard Desor in 1853.
Definition and GSSP
The stage begins with the first appearance of the Calpionellid species Calpionellites darderi and ends with the first appearance of the ammonite genus Acanthodiscus .
Breakdown
In the Tethys area, the valanginium is divided into five ammonite biozones:
- Criosarasinella furcillata
- Neocomites peregrinus
- Saynoceras verrucosum
- Busnardoites campylotoxus
- Tirnovella pertransiens
The Valanginium is further divided into the Lower Valanginium and Upper Valanginium . The first appearance of the ammonite Saynoceras verrucosum defines the beginning of the Upper Valanginian , with which the significant transgression Va3 began.
literature
- Felix Gradstein, Jim Ogg, Jim & Alan Smith: A Geologic timescale. Cambridge University Press 2005, ISBN 978-0-521-78673-7
- Hans Murawski & Wilhelm Meyer: Geological dictionary . 10., rework. u. exp. Ed., 278, Enke Verlag, Stuttgart 1998 ISBN 3-432-84100-0 .
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). Vienna 2004 (PDF; 376 KB)
- International Chronostratigraphic Chart 2012 (PDF)