Permian

Permian strata in the British Isles crop out mainly in northern and central England but are extensive in the subsurface both on land and in several adjoining offshore areas. Their base is defined as in Smith et al. (1974) and their top is within red beds, overlying the Zechstein evaporites.We emphasize that both the base and the top of the nominally Permian rocks lie in continental strata almost devoid of stratigraphically useful fossils and that, accordingly, these boundaries are only doubtfully correlated with internationally acceptable biostratigraphic standards.Subdivision of British Permian strata into Lower and Upper series follows the traditional view summarized by Smith et al. (1974). The junction between the series is taken at the incoming of marine strata in northern England and adjoining offshore areas, and at approximately equivalent levels in continuous continental sequences elsewhere; recent limited palynological studies suggest that the early Permian-late Permian transition adopted here and in most of northwest Europe may be mid or late Kazanian or even Tatarian in age which is somewhat younger than the base-Kazanian/Ufimian position taken in more continuous marine sequences.There has been no comprehensive revision of the stratigraphy and nomenclature of early Permian strata in and around the British Isles since the work of Smith et al. (1974) and Rhys (1974), but these aspects of the early Permian continental deposits of several cuvettes and inland drainage basins in southwest Scotland were reviewed by Brookfield (1978) and the age of continental deposits in the Elgin area was reconsidered