Coal Measures Group

The Coal Measures Group is a lithostratigraphical term coined to refer to the coal-bearing succession of rock strata which occur in Great Britain within the Westphalian Stage of the Carboniferous Period. The Coal Measures Group is preceded (underlain) by the Millstone Grit Group which is of Namurian age. It is succeeded (overlain) by the Warwickshire Group which comprises a largely non-productive sequence of red beds.^[1] Within the Pennine Basin it comprises the:

• Upper Coal Measures Formation
• Middle Coal Measures Formation
• Lower Coal Measures Formation

The 'Pennine Basin' includes all of the coalfields of northern England and the English Midlands together with the Canonbie Coalfield of southern Scotland and the coalfields of northeast Wales and Anglesey.

A similar scheme operates in the Midland Valley Basin of Scotland. In those coalfields to the south of the former Wales-Brabant High ie the South Wales, Bristol, Somerset and Forest of Dean Coalfields, the corresponding group is the South Wales Coal Measures Group. It comprises the:

• Middle Coal Measures Formation
• Lower Coal Measures Formation

In South Wales, the Upper Coal Measures Formation is grouped with the Pennant Sandstone Formation in the overlying Warwickshire Group.^[2] The South Wales Coal Measures Group is preceded (underlain) by the Marros Group.

References

1. ^ Powell, J.H. et al. 2000. Stratigraphical framework for Westphalian to early Permian red-bed successions of the Pennine Basin, British Geological Survey Research Report, RR/00/01
2. ^ British Geological Survey 1:625,000 scale geological map Bedrock geology: UK South (5th edn) BGS, Keyworth, Notts