South-Central Barents Sea Composite Tectono-Sedimentary Element

Abstract

Abstract The south-central Barents Sea today comprises a shallow continental shelf with water depths mainly in the 200–400 m range, straddling the Norway–Russia marine boundary. Geologically, it consists of a stable platform (the Bjarmeland Platform) dissected by rifts of probable Late Carboniferous age, with a significant and geologically persistent basement high (the Fedynsky High) in its southeastern part. The rifts are the ENE–WSW-trending Nordkapp Basin, the similarly trending but less clearly demarcated Ottar Basin and the NW–SE Tiddlybanken Basin. The varying rift trends appear to reflect the orogenic grain patchwork of the basement (Caledonide and Timanide), and these basins were infilled with a variable facies assemblage including substantial Carboniferous–Permian halites. A massive sedimentary influx of fluvio-deltaic to shallow-marine sediments took place in the Triassic, from the east and SE (Urals, Novaya Zemlya and western Siberia) and the south (Baltic Shield), resulting in doming and diapirism in the areas of thickest salt, particularly in the rifts. The succeeding Jurassic, Cretaceous and Cenozoic successions are generally thin, locally thickening in rim synclines and in the NE of the area towards the deep basins flanking Novaya Zemlya. Reactivation of the halokinetic structures took place in the early Cenozoic, probably associated with the development of the NE Atlantic–Arctic Ocean linkage. Marine source rocks of Triassic and Late Jurassic age are present in the area, along with Carboniferous and Permian source rocks of uncertain effectiveness. Petroleum has been found in Jurassic and Triassic clastic reservoirs, including recent shallow Jurassic oil and gas discoveries. Although none is currently in production, near-future oil development is likely in the Wisting discovery, on the western margin of the area. New exploration, including drilling, has taken place in the east of the area as a result of recent Norwegian and Russian licensing.