Bacton Group
The Bacton Group is a Triassic lithostratigraphic group beneath the southern part of the North Sea. The name is derived from Bacton on the Norfolk coast. These strata, which are up to 600 m thick are the offshore equivalent of the Roxby Formation and Sherwood [Sandstone Group] which occur in northeast England. The group comprises a lower Bunter Shale Formation of red and brown to grey mudstones and an upper Bunter Sandstone Formation of dolomitic sandstones with mudstone interlayers.