Valanginian
| Valanginian | |||||||||
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| Chronology | |||||||||
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| Etymology | |||||||||
| Name formality | Formal | ||||||||
| Usage information | |||||||||
| Celestial body | Earth | ||||||||
| Regional usage | Global (ICS) | ||||||||
| Time scale(s) used | ICS Time Scale | ||||||||
| Definition | |||||||||
| Chronological unit | Age | ||||||||
| Stratigraphic unit | Stage | ||||||||
| Time span formality | Formal | ||||||||
| Lower boundary definition | FAD of Thurmanniceras pertransiens (Ammonite)[2] | ||||||||
| Lower boundary GSSP | Montbrun-les-Bains, Drôme, France Lua error: callParserFunction: function "#coordinates" was not found. | ||||||||
| Lower GSSP ratified | December 2024[3] | ||||||||
| Upper boundary definition | FAD of the Ammonite genus Acanthodiscus | ||||||||
| Upper boundary GSSP | La Charce, Drôme, France Lua error: callParserFunction: function "#coordinates" was not found. | ||||||||
| Upper GSSP ratified | December 2019[4] | ||||||||
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 137.05 ± 0.2 Ma and 132.6 ± 0.2 Ma (million years ago).[5] The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceous and precedes the Hauterivian Stage of the Lower Cretaceous.[6]
Stratigraphic definitions
[edit | edit source]The Valanginian was first described and named by Édouard Desor in 1853. It is named after Valangin, a small town north of Neuchâtel in the Jura Mountains of Switzerland.
The base of the Valanginian is at the first appearance of ammonite species Thurmanniceras pertransiens,[2] with a global reference section (a GSSP) appointed in December 2024.[3]
The top of the Valanginian (the base of the Hauterivian) is at the first appearance of the ammonite genus Acanthodiscus.[citation needed]
Subdivision
[edit | edit source]The Valanginian is often subdivided in Lower and Upper substages. The Upper substage begins at the first appearance of ammonite species Saynoceras verrucosum and the major marine transgression Va3.
In the Tethys domain, the Valanginian stage contains five ammonite biozones:
- zone of Criosarasinella furcillata
- zone of Neocomites peregrinus
- zone of Saynoceras verrucosum
- zone of Busnardoites campylotoxus
- zone of Tirnovella pertransiens [citation needed]
Flora
[edit | edit source]The oldest fossils that can definitely be attributed to the clade Angiospermae (flowering plants) are dated to the Late Valanginian.[7]
References
[edit | edit source]Notes
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- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Cohen, K.M., Finney, S.C., Gibbard, P.L. & Fan, J.-X. (2013; updated) The ICS International Chronostratigraphic Chart. Episodes 36: 199–204.
- ^ See Gradstein et al. (2004) for a detailed geologic timescale
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
Literature
[edit | edit source]- Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; (2004): A Geologic Time Scale 2004, Cambridge University Press.
External links
[edit | edit source]- GeoWhen Database - Valanginian
- Mid-Cretaceous timescale and ühttp://stratigraphy.science.purdue.edu/charts/Timeslices/5_JurCret.pdf Jurassic-Cretaceous timescale], at the website of the subcommission for stratigraphic information of the ICS
- Stratigraphic chart of the Lower Cretaceous, at the website of Norges Network of offshore records of geology and stratigraphy
| Cenozoic Era (present–66.0 Ma) |
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| Mesozoic Era (66.0–252 Ma) |
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| Paleozoic Era (252–539 Ma) |
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| Proterozoic Eon (539 Ma–2.5 Ga) |
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| Archean Eon (2.5–4 Ga) | |||||||||||||
| Hadean Eon (4–4.6 Ga) | |||||||||||||
ka = kiloannum (thousand years ago); Ma = megaannum (million years ago); Ga = gigaannum (billion years ago). See also: Geologic time scale • Lua error in mw.title.lua at line 392: bad argument #2 to 'title.new' (unrecognized namespace name 'Portal'). • Lua error in mw.title.lua at line 392: bad argument #2 to 'title.new' (unrecognized namespace name 'Portal'). | |||||||||||||
