Geology of Alderley Edge - Nomenclature

Nomenclature

The nomenclature of the English Triassic was rewritten in the 1980s and many of the previous names were changed. The classic terms ‘Bunter’ and ‘Keuper’ have now been abandoned, and the formations now recognized in the UK Triassic sequences, constitute three major lithostratigraphical units,

• the Sherwood Sandstone Group (arenaceous siliciclastic) (equivalent to the Bunter and lower Keuper)
• the Mercia Mudstone Group (argillaceous, halitic) (equivalent to the Keuper Marl)
• the Penarth Group (not seen at Alderley).

For this reason, in places, the older names with appropriate cross references are used, in order to maintain an understanding of earlier work.

For a description of some of the other terms used see Geological unit