Viséan

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Viséan
346.7 ± 0.4 – 330.9 ± 0.2 Ma
Laurasia 330Ma.jpg
Paleogeography of the late Viséan
Chronology
Etymology
Name formalityFormal
Alternate spelling(s)Visean, Visian
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the benthic foraminifer
Lower boundary GSSP, Guangxi, China
24°26′00″N 109°27′00″E / 24.4333°N 109.4500°E / 24.4333; 109.4500
GSSP ratified2008
Upper boundary definitionNot formally defined
Upper boundary definition candidatesFAD of the conodont Lochriea ziegleri
Upper boundary GSSP candidate section(s)

The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 346.7 to 330.9 Ma.[2] It follows the Tournaisian age/stage and is followed by the Serpukhovian age/stage.

Name and definitions[]

The Viséan Stage was introduced by Belgian geologist André Dumont in 1832. Dumont named this stage after the city of Visé in Belgium's Liège Province. Before being used as an international stage, the Visean Stage was part of the (West) European regional geologic time scale, in which it followed the Tournaisian Stage and is followed by the Namurian Stage. In the North American regional scale, the Visean Stage correlates with the upper Osagean, the Meramecian and lower Chesterian stages. In the Chinese regional time scale, it correlates with the lower and middle Tatangian series.[3]

The base of the Viséan Stage is at the first appearance of the fusulinid species (morphotype 1/morphotype 2). The type locality for the stage base used to be in a road section below the castle of Dinant in Belgium, but this type locality proved to be insufficient for the purpose of stratigraphic correlation.[3] A GSSP has been proposed in the near Penchong in the Chinese province of Guanxi.[4] The top (the base of the Serpukhovian and Namurian) is laid at the first appearance of the conodont Lochriea ziegleri,[5] or at the base of the biozone of goniatite Cravenoceras leion.

Tetrapods[]

One of the tetrapods that lived during the Visean age was Westlothiana, a reptile-like amphibian.

Biostratigraphy[]

The Visean contains four conodont biozones:

In British stratigraphy, the Visean is subdivided into five substages. These are from bottom to top: Chadian (the lower part of this substage falls in the Tournaisian), Arundian, Holkerian, Asbian and Brigantian.[6]

References[]

  1. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  2. ^ "International Chronostratigraphic Chart". International Commission on Stratigraphy. Retrieved 9 December 2012.
  3. ^ a b Menning, M.; Alekseev, A.S.; Chuvashov, B.I.; Davydov, V.I.; Devuyst, F.-X.; Forke, H.C.; Grunt, T.A.; Hance, L.; Heckel, P.H.; Izokh, N.G.; Jin, Y.-G.; Jones, P.J.; Kotlyar, G.V.; Kozur, H.W.; Nemyrovska, T.I.; Schneider, J.W.; Wang, X.-D.; Weddige, K.; Weyer, D. & Work, D.M.; 2006: Global time scale and regional stratigraphic reference scales of Central and West Europe, East Europe, Tethys, South China, and North America as used in the Devonian–Carboniferous–Permian Correlation Chart 2003 (DCP 2003), Palaeogeography, Palaeoclimatology, Palaeoecology 240 (1-2): pp 318–372.
  4. ^ Devuyst, F.X.; Hance, L.; Hou, H.-F.; Wu, X.; Tian, S.; Coen, M. & Sevastopulo, G.; 2003: A proposed Global Stratotype Section and Point for the base of the Visean Stage (Carboniferous): the Pengchong section, Guangxi, South China, Episodes 26 (2), pp 105–115
  5. ^ Nemyrovska, T.I.; 2005: Late Visean/early Serpukhovian conodont succession from the Triollo section, Palencia (Cantabrian Mountains, Spain), Scr. Geol. 129, pp 13–89
  6. ^ Heckel, P.H. & Clayton, G.; 2006: The Carboniferous system, use of the new official names for the subsystems, series and stages, Geologica Acta 4(3), pp 403–407.

Further reading[]

  • Dumont, A.H.; 1832: Mémoire sur la constitution géologique de la province de Liège, Mémoires couronnés par l'Académie Royale des Sciences et Belles-Lettres de Bruxelles 8 (3), VII. (in French)

External links[]

Coordinates: 24°26′00″N 109°27′00″E / 24.4333°N 109.4500°E / 24.4333; 109.4500

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