NEW INSIGHTS ON EAST FINNMARK PLATFORM PALYNOSTRATIGRAPHY – TOWARDS A MISSISSIPPIAN (EARLY CARBONIFEROUS) PALYNOZONATION OF THE BARENTS SEA AREA

The Finnmark Platform, located offshore northern Norway was, during the Late Paleozoic, a vast E-W oriented intra-cratonic basin on the northern margin of the Euramerican Supercontinent. The oldest sedimentary unit, the Billefjorden Group, consists mainly of continental siliciclastic rocks ranging in age from Late Devonian to Mississippian. The regional development of the Billefjorden Group is still relatively poorly known. Although few palynological papers have been published, palynology has proved to be the only tool for dating this part of the succession. However, more studies are needed in order to fully understand the stratigraphic ranges and quantitative distribution of all the palynomorph taxa present.

A biozonal scheme for the Mississippian succession (Billefjorden Group) of the Barents Sea is currently being developed and the first palynological results are presented here. Cores have been analysed from three shallow stratigraphic wells (7127/10-U-2; 7127/10-U-3; 7029/3-U-1) drilled on Finnmark Platform. Four assemblages and two sub-assemblages were recognized from the Billefjorden Group. Based on correlation with the Western Europe Biozonal Scheme and a previously published local biozonal scheme, the following assemblages are erected in ascending stratigraphic order: Assemblage I, low diversity, abundant Lycospora pusilla and Punctatisporites spp. and absence of Schulzospora spp. ; Assemblage II, including the first appearance of Perotriletes tessellatus and Schulzospora campyloptera; Assemblage III, defined by the first appearance of Raistrickia nigra; Tripartites vetustus; Triquitrites marginatus; Rotaspora cf. R. fracta and Murospora margodentata, incorporating two sub-assemblages differentiated by different dominant taxa; Assemblage IV, a poorly diverse assemblage, based on the first appearance of Stenozonotriletes bracteolus, Rotaspora crenulata and Triquitrites sp. A, and an increase in abundance of several taxa including Tripartites vetustus and Tripartites nonguerickei.

This project is supported by University of Bergen and the FORCE Industry Consortium sponsored by BG Group, Chevron, Detnorske, E-On, Faroe Petroleum and VNG Norge.