The Lower Follifoot Grit, Silver Hills Sandstone, Nottage Crag Grit, Marchup Grit, Red Scar Grit, Ward's Stone Sandstone, Cocklett Scar Sandstones and Dure Clough Sandstones are all assigned to the following Arnsbergian sub-stage.
The closing sub-stage of the Namurian, the Yeadonian includes the Lower Haslingden Flags and the last sandstone in the entire Millstone Grit succession known as the Rough Rock.