Coal measures

In lithostratigraphy, coal measures are coal-bearing strata, with the term typically applied to European units of the Upper Carboniferous System.

The group records the deposition of fluvio-deltaic sediments which consists mainly of clastic rocks (claystones, shales, siltstones, sandstones, conglomerates) interstratified with the beds of coal.

In most places, the coal measures are underlain by coarser clastic sequences known as Millstone Grit, of Namurian age.

In some parts of Britain, however, the coal measures grade up into mainly coal-barren red beds of late Westphalian and possibly Stephanian age.

[1][2] Within the Pennine Basin, these barren measures are now referred to as the Warwickshire Group, from the district where they achieve their thickest development.