Unconformities related to the Jurassic–Cretaceous synrift–post-rift transition of the northern North Sea

摘要: In the Jurassic–Cretaceous North Sea basin, synrift sequence is separated from post-rift by ‘base Cretaceous’ or ‘late Cimmerian’ unconformity. The unconformity covers almost entire has a distinct character in seismic reflection data and wireline logs, hence, easily identified correlated, making it most important marker horizon area. displays great local complexity (in many localities) variability on regional scale (from one locality to another). Thus classified as nonconformity, disconformity an angular We suggest that these variations basically reflect different structural position within so short-wavelength variation dominated development (e.g. rotational history of fault block), whereas long-wavelength reflects basin-scale tectonic, thermal isostatic processes. merging this with younger erosional surfaces, its complex configuration polychronous makes general term Cretaceous unconformity’ inadequate. Thus, ‘northern Unconformity Complex’ used here.