The macrofossil biostratigraphy of the Turonian and Coniacian (Upper Cretaceous, Chalk Group) of southeast Devon

During the re-surveying of the Sidmouth district by the British Geological Survey, coastal sections and nearby quarries in the Chalk Group of southeast Devon, between Beer Head and Lyme Regis, were logged and collected for macrofaunas. This work has allowed the first detailed definition and characterization of macrofossil biozones in the Turonian and Coniacian chalk successions of the region since the work of Rowe, nearly a century ago. The combination of macrofossil and lithostratigraphical observations has allowed some key marker beds in the stratotype White Chalk Subgroup of Sussex to be traced through to Southeast Devon. Lateral contrasts in the development of biozones are matched by changes in the thickness and facies of lithostratigraphical units, and Suggest the likely influence of basin architecture and/or tectonics on local patterns of chalk deposition.