Revealing the Salt Tectonic Puzzle: Mesozoic Base of the Norwegian North Sea

This article expands on the EAGE extended abstract ‘Structural Styles and Lithology Changes at the Mesozoic Base from Ultra-Large 3D Seismic’, to be presented at the 86th EAGE Annual Conference in Toulouse. The project’s interpretation and the structural grid for the Norwegian Continental Shelf are publicly available, a shared resource for researchers, students, and energy companies. The study covers the details of a seismic interpretation of the Mesozoic base — a major unconformity mapped at the top of the Permian Zechstein Supergroup and the acoustic basement, where Zechstein onlaps the older strata. This surface underlies key Triassic, Jurassic, and Cretaceous hydrocarbon units, important for subsurface mapping, exploration, and petroleum systems modelling. Using a reprocessed, ultra-large broadband 3D seismic dataset (78,450 km2) across the North (NNS), Central (CNS), and South (SNS) zones of the Norwegian North Sea and 817 wells, the study integrates recent advances in salt tectonics and the Zechstein lithology research (Figure 1). Previous findings are integrated into a consistent interpretation of structural styles and lithological variation. Understanding Mesozoic base morphology and Zechstein compositional trends has significant implications for identifying prospective plays and reservoirs, including the Zechstein salt bed potential for underground storage suitability.