Moscovian age

Not to be confused with Moscovium.

The Moscovian is in the ICS geologic timescale a stage or age in the Pennsylvanian, the youngest subsystem of the Carboniferous. The Moscovian age lasted from 315.2 to 307 Ma,^[2] is preceded by the Bashkirian and is followed by the Kasimovian. The Moscovian overlaps with the European regional Westphalian stage and the North American Atokan and Desmoinesian stages.

Moscovian
315.2 ± 0.2 – 307.0 ± 0.1 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Paleogeography of the Moscovian, 310 Ma
Chronology
−360 — – −355 — – −350 — – −345 — – −340 — – −335 — – −330 — – −325 — – −320 — – −315 — – −310 — – −305 — – −300 — – Paleozoic D Carboniferous P Mississippian Pennsylvanian LD Early Middle Late Early Mid Late CS Famennian Tournaisian Viséan Serpukhovian Bashkirian Moscovian Kasimovian Gzhelian Asselian     ← Carboniferous Rainforest Collapse ← Mazon Creek Fossils ← End of Romer's Gap ← Start of Romer's Gap Subdivision of the Carboniferous according to the ICS, as of 2023.[1] Vertical axis scale: Millions of years ago
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	Not formally defined
Lower boundary definition candidates	FAD of the Conodont Idiognathoides postsulcatus or Declinognathodus donetzianus
Lower boundary GSSP candidate section(s)	Southern Ural Mountains Nashui, Luodian County, Guizhou, China
Upper boundary definition	Not formally defined
Upper boundary definition candidates	FAD of the Fusulinid Protriticites or 1 million years older Montiparus montiparus
Upper boundary GSSP candidate section(s)	Southern Ural mountains Southwest USA Nashui, Luodian County, Guizhou, China

Name and definition

The Moscovian Stage was introduced by Sergei Nikitin (1850 - 1909) in 1890, using brachiopods in the Moscow Basin of European Russia. Nikitin named the stage after Moscow, then a major city and now the capital of Russia.

The base of the Moscovian is close to the first appearances of the conodonts Declinognathodus donetzianus and Idiognathoides postsulcatus^[3] or otherwise the fusulinid Aljutovella aljutovica.^[4] Because the fusulinid species are regionally different, they can not be used for worldwide correlation. A Global Boundary Stratotype Section and Point for the Moscovian Stage has yet to be defined (2008). A proposal is to use the first appearance of the conodont Diplognathodus ellesmerensis, but since the species is rare and its evolution relatively unknown, it has not been accepted yet.^[5]

The top of the Moscovian (base of the Kasimovian) is at the base of the fusulinid biozone of Obsoletes obsoletes and Protriticites pseudomontiparus, or with the first appearance of the ammonite genus Parashumardites.

Subdivisions

In European Russia and Eastern Europe, where the stage was first recognized, the Moscovian is subdivided into four regional substages: Vereiskian, Kashirskian, Podolskian, and Myachkovskian, named after towns near Moscow (Vereya, Kashira, Podolsk, and Myachkovo).

The Moscovian can biostratigraphically be divided into five conodont biozones:

• Neognathodus roundyi and Streptognathodus cancellosus Zone
• Neognathodus medexultimus and Streptognathodus concinnus Zone
• Streptognathodus dissectus Zone
• Neognathodus uralicus Zone
• Declinognathodus donetzianus Zone