Berriasium
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 Berriasium (in German usage also shortened to Berrias , more rarely also Berriasias) is the oldest chronostratigraphic level of the Lower Cretaceous in the history of the earth . On the geochronological time scale, the stage corresponds to the period from approximately 145 to 139.3 million years. The Berriasium follows the Tithonium (youngest stage of the Jurassic ) and is replaced by the Valanginium .
Naming and history
The step is after the place Berrias in French department Ardèche named. The level and name were introduced into scientific literature by Henri Coquand in 1869 . In the past, the stage in the transition from Jura to Lower Cretaceous in northern Germany was also known as Wealden .
Definition and GSSP
The beginning of the stage is (presumably) defined by the first appearance of the ammonite species Berriasella jacobi . A GSSP (global type locality and type profile) has not yet been defined. The end of the stage is also only provisionally determined with the first appearance of the Calpionella species Calpionellites darderi . No GSSP has yet been defined for the base of the Valanginium either. The ammonite species Thurmanniceras pertransiens also sets in just a little above the targeted Berriasium / Valanginium border .
Subdivision of the Berriasium
The Berriasium in the Tethyalen area is divided into four ammonite biozones:
Individual evidence
literature
- Felix Gradstein, Jim Ogg, Jim & Alan Smith: A geologic time scale. Cambridge University Press 2005, ISBN 0-521-78673-8
- 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)