Carboniferous rocks within this area occupy the region to the south of, and contiguous with, the Southern Pennines (see Chapter 11). The oldest Tournaisian and Visean strata occur at outcrop within the Peak District, represented by ramp-to-shelf carbonates (Peak Limestone Group) deposited on the Derbyshire High, a promontory of the East Midlands Shelf, and the laterally extensive Staffordshire and Hathern shelves. The platform carbonates of the East Midlands Shelf extend in the subsurface below Nottinghamshire and Lincolnshire, where the nature of the succession is based largely upon well records and geophysical information (Strank 1987). A 23 m thick succession of platform carbonates is recorded in the base of the Saltfleet by No. 3 Borehole [TF 4246 9135] (Hodge 2003) and at least 100 m is present in the Welton Oil-field (Fig. 31). The Derbyshire High platform carbonate rocks pass into more basinal successions in the Edale Basin to the north, the Widmerpool Gulf to the south and the Staffordshire Basin to the west, dominated by hemi-pelagic mudstone and carbonate turbidites (Craven Group). The lithostratigraphical nomenclature for the Tournaisian and Visean strata is that of Waters et al. (2009), adapted from Aitkenhead & Chisholm (1982).