Turonian
| Turonian | |
|---|---|
Inoceramid Bivalve Cremnoceramus rotundatus | |
| Upper boundary GSSP candidate section(s) |
|
The Turonian is, in the
At the beginning of the Turonian an oceanic anoxic event (OAE 2) took place, also referred to as the Cenomanian-Turonian boundary event or the "Bonarelli Event".[4] Sea level fall took place in the latter part of the Turonian from the highstand at the beginning of the Turonian.[5]
Stratigraphic definition
The Turonian (French: Turonien) was defined by the French paleontologist Alcide d'Orbigny (1802–1857) in 1842. Orbigny named it after the French city of Tours in the region of Touraine (department Indre-et-Loire), which is the original type locality.[citation needed]
The base of the Turonian Stage is defined as the place where the
The top of the Turonian Stage (the base of the Coniacian) is defined as the place in the stratigraphic column where the
Subdivision
The Turonian is sometimes subdivided in Lower/Early, Middle and Upper/Late substages or subages. In the Tethys domain, it contains the following ammonite biozones:
- zone of Subprionocyclus neptuni (in the Upper Turonian)
- zone of Collignoniceras woollgari (in the Middle Turonian)
- zone of Mammites nodosoides
- zone of Watinoceras coloradoense or Watinoceras devonense (last two both in the Lower Turonian)
Other important
References
- ^ International Commission on Stratigraphy. "ICS - Chart/Time Scale". www.stratigraphy.org.
- .
- ^ See Gradstein et al. (2004) for a detailed description of the ICS' timescale
- .
- ^ Wiese, Frank; Kröger, Björn (January 1998). "Evidence for a shallowing event in the Upper Turonian (Cretaceous) Mytiloides scupini Zone of northern Germany". Acta Palaeontologica Polonica. 48 (3): 265–284. Retrieved 15 December 2023.
- ^ The GSSP was established by Kennedy et al. (2005)
Literature
- Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
- Kennedy, W.J.; Walaszczyk, I. & Cobban, W.A.; 2005: The Global Boundary Stratotype Section and Point for the base of the Turonian Stage of the Cretaceous: Pueblo, Colorado, U.S.A., Episodes 28(2): pp 93–104.
External links
- GeoWhen Database - Turonian
- Late Cretaceous timescale, at the website of the subcommission for stratigraphic information of the ICS
- Stratigraphic charts of the Cretaceous: [1] and [2], at the website of Norges Network of offshore records of geology and stratigraphy
- Turonian Microfossils: 48 images of Foraminifera
