UPPER PALEOZOIC SUCCESSION ON THE FINNMARK PLATFORM, BARENTS SEA

During the Late Palaeozoic, sediments were deposited in the proto-Bare nts Sea along the northern margin of the Fennoscandian Shield. These s ediments have no outcrops onshore Norway, but a condensed Upper Palaeo zoic succession occurs on the Finnmark Platform close to the present c oast of Norway. During 1987 and 1988, IKU Petroleum Research cored mos t of the condensed, 600-700 m thick sedimentary section, and except fo r about 100 m, the entire Carboniferous-Permian succession was cored. Using high resolution multichannel seismic data, fourteen seismic unit s have been defined in the cored succession. These are grouped into fo ur stratigraphic intervals and discussed in a stratigraphic context ba sed on seismic, sedimentological and biostratigraphic data The dating is based on palynomorphs in the elastic-dominated Lower Carboniferous succession, by fusulinids in the carbonate-dominated Upper Carbonifero us/Lower Permian succession, and by palynomorphs in the elastic-domina ted Upper Permian and lowermost Triassic succession. A major transgres sion affected the Finnmark Platform in the Early Carboniferous (Visean ), and marine shale was deposited in the east, while a local basin in the west was filled by flood plain deposits up to 650 m thick. An over all transgressive trend through the ?Bashkirian to Kasimovian (Mid-Lat e Carboniferous) gave flood plain to shoreface deposits on the souther n Finnmark Platform. A carbonate platform with significant elastic inp ut existed from the Late Carboniferous (Gzhelian) to Late Permian, wit h Palaeoaplysina-phylloid algal buildups forming during the Gzhelian-A sselian and bryozoan buildups during the Sakmarian-Artinskian (Early P ermian). The clastic input increased during the Late Permian, and at t he Permian/Triassic transition the carbonate shelf was transgressed an d covered by elastic sediments prograding from the east and southeast.