Namurian
The Namurian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 326 and 313 Ma. 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. 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 and succeeded by the Westphalian stage/age. In the official geologic timescale of the ICS, the Namurian straddles the boundary between the Mississippian epoch and the Pennsylvanian epoch.
The upper part of the Namurian stage corresponds to the 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.
