Distinction between fault and salt control of Mesozoic sedimentation on the southern margin of the Mid-North Sea High

Abstract

Abstract The North Dogger Fault Zone (NDFZ) is situated at the northern margin of the UK Southern North Sea Basin at the northern limit of the mobile Zechstein Supergroup. This fault zone underwent movement during late Triassic and probably early Jurassic times. The NDFZ is comparable with the southern part of the Dowsing Fault Zone (SDFZ), which was initiated during late Scythian times and continued to move until at least mid-Carnian times. The SDFZ is located at the southwestern edge of mobile salt. Both fault zones form part of the basin-bounding fault system, which is proposed to have been initiated as a response to the growth of salt swells in the centre of the Southern North Sea Basin. The fault formation is due to folding of the Triassic strata over the swells and overall shortening of the Triassic cover. The shortening was taken up as extension at the basin margins, corresponding to the edge of the mobile Zechstein salt.