The Warwickshire coalfield extends between Warwick and Tamworth in the English Midlands.[1] It is about 25 miles (40 km) from north to south and its width is around half that distance. Its western margin is defined by the 'Western Boundary Fault'. In the northeast it abuts against steeply dipping shales of Cambrian age. The larger part of the outcrop at the surface consists of the Warwickshire Group of largely coal-barren red beds.[2] Until its closure in 2013, the Daw Mill mine near Arley within the coalfield, was Britain's biggest coal-producer in the 21st century.[3]
Principal seams
The principal coal seams within the productive Lower and Middle Coal Measures include (in stratigraphic order i.e. youngest/uppermost first):[4][5]
Middle Coal Measures
Half Yard
Four Feet
Thin Rider
Two Yard
Bare
Ryder
Ell
Nine Feet
High Main
Smithy (Low Main)
Lower Coal Measures
Thin
Seven Feet
Trencher
Yard
Deep Rider
Double
Upper Bench (or Top Bench)
Bench Thin
Lower Bench
Stumpy
Stanhope
The Two Yard, Thin Rider, Ryder, Ell, Nine Feet, and High Main merge as one massive bed of coal known as the Thick Coal in parts of the coalfield.
Collieries
Collieries mining in the Warwickshire Coalfield were:[6]
