Structural evolution, timing and tectonic style of the Sole Pit inversion

Abstract

Abstract The NW-SE oriented Sole Pit High, located in the western half of the Southern North Sea Basin, is the result of three different structural processes initiated during the Late Palaeozoic. Basin subsidence, probably related to Late Hercynian pull-apart movements, led to continuous sedimentation from the Permian to the Middle Jurassic. Mid-Jurassic doming of its eastern flank, followed by erosion, transtensional movements and differential subsidence until the Early Cretaceous, reflect the Mid and Late Kimmerian crustal distension and fragmentation of the North Sea Rift. Basinwide inversion occurred between the Turonian and the Campanian and was repeated in the Oligocene resulting in a total uplift of some 1500 m. The present structural style is represented by a complex network of transpressional and transtensional faults at Permian Rotliegend levels, which are thought to represent the upward termination of a series of wrench-induced flower structures with a right-lateral sense of displacement. These faults are detached by Zechstein and Triassic salt from more orderly transtensional faults systems at shallower levels. In areas where salt is absent Late Kimmerian normal faults became reactivated in a reverse sense during inversion. However, the relationship of these shallow mappable tectonic components to the deeper pre-Permian structure of the Sole Pit High and to the underlying crustal configuration remains speculative.