Namurian

System	Series (NW Europe)	Stage (NW Europe)	Series (ICS)	Stage (ICS)	Age (Ma)
Permian					younger
Carboniferous	Silesian	Stephanian	Pennsylvanian	Gzhelian	299–303,9
		Westphalian		Kasimovian	303,9–306,5
				Moscovian	306,5–311,7
				Bashkirian	311,7–318,1
		Namurian
			Mississippian	Serpukhovian	318,1–326,4
	Dinantian	Visean		Visean	326,4–345,3
		Tournaisian		Tournaisian	345,3–359,2
Devonian					older
Subdivisions of the Carboniferous system in Europe compared with the official ICS-stages.

The Namurian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 326 and 313 Ma (million years ago). It is a subdivision of the Carboniferous system or period and the regional Silesian series. The Namurian is named for the Belgian city and province of Namur where strata of this age occur (part of the Belgian Coal Measures). The Millstone Grit Group in the lithostratigraphy of northern England and parts of Wales is also of Namurian age.

The Namurian age lasted from 326 to 313 million years ago. It is preceded by the Visean stage/age (which corresponds to the upper Carboniferous Limestone of Great Britain) and succeeded by the Westphalian stage/age (which corresponds to the lower and middle Coal Measures of Great Britain). In the official geologic timescale of the ICS, the Namurian straddles the boundary between the Mississippian epoch (359-318 Ma) and the Pennsylvanian epoch (318-299 Ma).^[1]

The upper part of the (regionally defined) Namurian stage corresponds to the (internationally used) Bashkirian stage whilst the lower part is assigned to the preceding Serpukhovian stage. Frequent references appear in scientific literature to a Namurian epoch or Namurian series reflecting the stage's earlier status.

References

1. ^ F M Gradstein, J G Ogg, A G Smith et al 2004, ‘A Geologic Time Scale 2004’.