f Post-Burial Deformation of Clastic Series, Mechanisms and Impact on Reservoir Geometry

Post-depositional, post-burial in situ defonnation of siliciclastic series is increasingly recognised as a common phenomenon affecting deep-water sediments. Well-known postburial features include sand sills and dykes, mud volcanoes, the former largely reported from the Palaeocene of the North Sea (e.g. Jenssen et al., 1993, Dixon et al., 1995) ; another related feature, more recently identified, is the large-scale polygonal pattem that affects thick basinal shale series in the North Sea and other areas (Cartwright, 1994, 1995, 1996).