Sedimentology and depositional environment of the Kobbe and Steinkobbe formations in the Nordkapp Basin, Sentralbanken High and the Svalis Dome, Barents Sea
MetadataVis full innførsel
The Mesozoic succession in the Barents Sea was deposited in a relatively shallow epicontinental basin that gradually were infilled during the Triassic by north and north-west progradation of an extensive deltaic system mainly sourced from the Baltic Shield in the south and the Uralian Mountains and the in the east and south-east.This study investigates the sedimentology and depositional environment of the Early to Middle Triassic Kobbe and Steinkobbe formations in the south-western Barents Sea. The material used is sediment cores from Sentralbanken High, The Nordkapp Basin and the Svalis Dome. The study aims to interpret the sedimentology of the different formations and to complement to the understanding of the temporal evolution of depositional environments in each area and the lateral distribution of facies between the three areas. This is done through a detailed facies analysis. Thirteen facies and seven facies associations are recognized and constitutes of a wide variety of proximal to distal facies. The most proximal facies associations are found in the Kobbe Formation from the Nordkapp Basin. The results show a regressive trend where shallow marine to prodeltaic deposits gradually is shallowing up to deposits associated with a coastal plain. Cores from Sentralbanken High and the Nordkapp basin both interpreted to be deposited on a relatively deep distal shelf. The lithology of Steinkobbe Formation reveals a regressive trend dominated by pelagic deposition which gradually becomes more influenced by deposition and modification of storms and/or turbidity currents. Steinkobbe at the Svalis Dome are interpreted to have been deposited during anoxic conditions whereas slightly better ventilation or shallower depths are suggested for the formation at Sentralbanken High.In general, there is a north to south deepening of facies which are in accordance to the theory of a sediment source located south-east of the studied areas and implies that the sediments are deposited in the early phase of the infill of the Barents Sea shelf.