Multichannel seismic data combined with weU-log information of Palaeocene and Eocene (lower Palaeogene) strata reveal the stratigraphy and lower Palaeogene evolution of the Tromsø Basin and adjacent areas. Four sequences are recognized. A Palaeocene sequence TtAI, a late Palaeocene to early Eocene sequence TtA2, and an early-mid-Eocene sequence TtB1 show progradation into the basin. Progradation ceased due to a relative rise of sea-level as sequence TtB2 of mid-?late Eocene times was deposited. The history of the Tromsø Basin mirrors the latest phase of tifting and early opening his tory of the Norwegian -Greenland Sea.Transpression caused uplift of highs adjacent to the basin area and led to progradation at the basin margins in late Palaeocene to early-mid-Eocene times, as represented by sequences TtAI, TtA2 and TtB1. Sequence TtB2 reflects increased subsidence rates and relative rise of sea-level in the ?late Eocene to ?early Oligocene as spreading of the Norwegian-Greenland Sea propagated northwards. Post ?early Oligocene times were characterized by several phases of erosion, leaving only Palaeocene to mid-?late Eocene marine facies preserved.
S.-M. Knutsen, JBG, University of Tromsø. Present address: Norsk Hydro a. s. P. O. Box 31, N-9401 Harstad, Norway;
L.-J. Skjold, Norsk Hydro a. s. Bergen, Norway;
P. H. Skott, Norsk Hydro a. s. P. O. Box 31, N-9401 Harstad, Norway.