Abstract The disparate coalfields and Carboniferous rocks in this area (Figs 28 & 29), mostly comprise Coal Measures lithofacies (Pennine Coal Measures Group) and red-bed sediments (Warwickshire Group) deposited at the southern margin of the Pennine Basin, which was initiated in Westphalian times. These strata generally rest unconformably on Lower Palaeozoic rocks in the west of the region, with local development of platform carbonates in Shropshire. The more extensive carbonate platform of the Hathern Shelf and coeval basinal mudstones (associated with the SE-trending Widmerpool Gulf) were deposited in the east of the region during late Tournaisian and Visean time. The basinal hemi-pelagic sedimentation continued in the SE throughout the early Namurian with an influx of southerly-derived quartzitic sandstone followed, in the Marsdenian, by northerly-derived feldspathic sandstone (Millstone Grit Group) (Fraser & Gawthorpe 2003). The oldest Carboniferous strata of late Tournaisian to Visean age do not crop out widely in the region, but are known from boreholes and geophysical records in South Derbyshire and the Vale of Belvoir, and from small inliers in Shropshire and the Clee Hills. Platform carbonates with thin beds of basic tuffite and subordinate sandstone (Peak Limestone Group) were deposited on the Hathern Shelf at the southern margin of the Widmerpool Gulf (half-graben) (Falcon & Kent 1960), but deepening of the basin through synsedimentary rift faulting and a rise in sea-level resulted in the deposition of deeper-water calcareous mud (Widmerpool Formation) (Fraser & Gawthorpe 2003).

Abstract The regional character of organic matter types and depositional conditions of Pendleian, Brigantian and Arnsbergian mudstones between the Craven Basin and the Widmerpool Gulf was compared through interpretation of biomarker and pyrolysis data from 201 samples recovered from nine boreholes. The Carboniferous seaways have been determined to commonly host dysoxic conditions, enabling the preservation of a mixture of marine and terrestrial organic matter types. Photic zone anoxia, established by the presence of aryl isoprenoids, was determined to be persistent during ‘marine’ conditions represented by marine band, high-sea-level and carbonate facies. The observation and correlation of diasteranes and trisnorneohopane/trisnorhopane ratios within the samples and to other maturity parameters highlighted a significant clay mineral catalytic and/or hydrocarbon retention effect in the samples. This influenced both biomarkers and programmed pyrolysis thermal maturity indices such as T max , reducing the reliability of such results for interpreting the burial depth, and ultimately reserve potential.

Abstract 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).

Abstract The Carboniferous basin development of northern England is illustrated in a series of regional seismic lines presented in this chapter. Each of the major syn– rift basins will be described in turn, using representative seismic lines (Fig. 10 ) that have been tied to well and outcrop control. In addition to the seismic data, depth converted geological interpretations for each of the seismic lines are presented to illustrate the development of these tectono–stratigraphic sequences across the province. Particular attention is paid to the Widmerpool Gulf because the combination of seismic quality, well penetrations and the presence of exposure of the syn–rift along–strike in Derbyshire allows us to discuss the tectono–stratigraphic sequences in detail. The depth converted geological interpretations are based on corrected sonic logs taken from nearby boreholes, where available. Elsewhere, and for the deeper Dinantian section on most lines, seismic stacking velocities have been applied. The errors inherent in this latter method could result in errors in the depth section of as much as ±10%. Typical velocities used in the depth conversion of the Eakring and Welton sections in the East Midlands and the Northumberland Trough (Kimbell et al. 1989) are shown in Table 1 .