E. G. Poole writes: The Enville Formation of the English Midlands has long (Murchison 1839) been regarded as Lower Permian in age with conclusive determinations of plants, amphibian and reptile remains specifically comparing with the type Upper Autunian of Germany (von Heune 1908; Haubold & Serjeant 1973; Paton 1974), and there is no support for the Westphalian D-Stephanian classification shown in fig. 3. Similarly the underlying Keele Formation contains tetropod tracks (amphibia and reptiles) which compare with those of the type Stephanian B deposits of Thuringia and the USA (Haubold & Serjeant 1973). The underlying Halesowen Formation (and its equivalents elsewhere) contains fossils such as Anthraconauta pruvosti Chernyshev and plants of the highest floral zones H and I (Dix 1934) many of which are accepted as Stephanian forms on the Continent. Although one cannot conclusively prove by fossils that the Halesowen Formation is of Stephanian or Westphalian age (Weir 1967, p. 406), it behaves in an identical manner to the basal Stephanian A Holzer Konglomerat of the Saar Basin, Germany, which uncomforably overlaps all the Namurian and Westphalian deposits after a major period of uplift, tectonics and erosion (Poole 1975, figs 3 & 4).
The underlying Etruria Formation is a primary red-bed facies which may be of any age from Westphalian B in the Dudley area (Poole 1970, fig. 1) to highest Westphalian (D?) in the South Lancashiere Coalfield where the primary red Barren Group (c. 100 m thick) is conformably overlain by the brackish water, grey beds with Spirorbis