There has been a recent revolution in the recognition of and production from low permeability ‘tight’ gas reservoirs. The distribution of faults within a unit of rock, as well as the origin and timing of these faults is of key importance in the evaluation of prospective ‘unconventional’ formations. This project explores the origin, characteristics and distribution of the faults within the Pre-Zechstein succession of the onshore and offshore Carboniferous basins of the eastern United Kingdom. The datasets utilised in the project include new 3D seismic data from the offshore southern North Sea, vintage 2D seismic data from the onshore Stainmore Trough and western Cleveland Basin, coalmine plan maps from the East Midlands region of the Pennine Basin and surface geological observations of the stratigraphically equivalent succession in North East England. The methods used to characterise the faults include (1) the detailed analysis of 3D seismic attributes, sampled at various Carboniferous intervals offshore; (2) fault throw mapping performed on areas in which good reflection correlations could be mapped, and (3) the sampling of fault frequency and spacings using the 1D scanline method, so that it can be applied to different data types. Through these methods, the fault geometries, spatial distribution, kinematics and possible formation and reactivation mechanisms have been addressed. The detailed fault patterns across the East Pennine and Anglo-Dutch Basins therefore exhibit a complex formation and reactivation history that cannot be explained only by rotations of the regional stress field and the alternation of periods of tectonic extension and compression alone. There is a clear relationship between three profoundly different structural style types. A primary faulting mechanism resulting from regional tectonic stresses (throughgoing), and two secondary faulting processes that are in response to the tectonic fault formation and the accompanying deformation (superficial and detachment). The key controlling factors on ...