Kasimovian

System	Subsystem/ Series	Stage	Age (Ma)
Permian	Cisuralian	Asselian	younger
Carboniferous	Pennsylvanian	Gzhelian	299.0–303.9
		Kasimovian	303.9–306.5
		Moscovian	306.5–311.7
		Bashkirian	311.7–318.1
	Mississippian	Serpukhovian	318.1–328.3
		Viséan	328.3–345.3
		Tournaisian	345.3–359.2
Devonian	Upper	Famennian	older
Subdivision of the Carboniferous system according to the ICS.

The Kasimovian is an geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian (late Carboniferous), lasting from 306.5 ± 1.0 to 303.9 ± 0.9 Ma. The Kasimovian stage follows the Moscovian and is followed by the Gzhelian.

Name and definition

The Kasimovian is named after the Russian city of Kasimov. The stage was split from the Moscovian in 1926 by Boris Dan'shin (1891-1941), who gave it the name Teguliferina horizon. The name was posthumously changed in Kasimov horizon by Dan'shin in 1947. The name Kasimovian was introduced by Georgy Teodorovich in 1949.

The base of the Kasomovian stage is at the base of the fusulinid biozone of Obsoletes obsoletes and Protriticites pseudomontiparus or with the first appearance of the ammonite genus Parashumardites. The top of the stage is close to the first appearances of the fusulinid genera Daixina, Jigulites and Rugosofusulina or the first appearance of the conodont Streptognathodus zethus. The golden spike for the Kasimovian stage has not yet been assigned (in 2008).

Biozones

The Kasimovian is subdivided into three conodont biozones:

• Idiognathodus toretzianus Zone
• Idiognathodus sagittatus Zone
• Streptognathodus excelsus and Streptognathodus makhlinae Zone

Literature

• Dan'shin, V.M.; 1947: Geology and Mineral Resources of Moscow and its Surroundings, Izdat. Moskov. Obshch. Isp. Prir., Moscow, 308 pp. ((Russian)).
• Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
• 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.
• Teodorovich, Georgy I. (1949). "[On the subdivision of the Upper Carboniferous into stages]" (in Russian). Doklady Akademii Nauk SSSR 67 (3): 537–540. 

External links

• Carboniferous timescale at the website of the Norwegian network of offshore records of geology and stratigraphy
• Kasimovian, GeoWhen Database