QUATERNARY OF THE NORWEGIAN CHANNEL - GLACIATION HISTORY AND PALEOCEANOGRAPHY

Sediment cores from a borehole penetrating the upper Aat-lying reflect ors (ca. 200 m) above the angular unconformity in the Norwegian Channe l off western Norway have been investigated. Lithological, biostratigr aphical (foraminifera) and geochronological (C-14, amino acid, stronti um isotopes and palaeomagnetism) analyses,combined with shallow seismi c data From the region, have been used to interpret the Quaternary dep ositional history of the Norwegian Channel, Three thick and extensive till units, each with sharp, erosional lower boundaries are interbedde d with marine sediments. The oldest till unit (representing the Fedje Glaciation) is situated directly on top of the angular unconformity an d suggests glacial erosion as the major process in the formation of th e Norwegian Channel. The age of this till unit is ca. 1.1 Ma. Above th is unit follows a ca. 50-m thick marine unit deposited between 1.1 Ma and ca. 0.6 Ma. A warm phase with conditions close to the present ones (the Radoy Interglacial) is recorded in the lower part of this unit, suggesting a strong advection of Atlantic water into the Norwegian Sea region. Following a relatively cool interval, a Further warm period ( the Norwegian Trench Interglacial) is recorded above the Brunhes/Matuy ama boundary (0.7 Ma). Above this follows a till unit of Middle Pleist ocene age. Between this and a Weichselian till, a pocket of more sorte d material is identified at the Troll Field. Within this pocket, sedim ents of last interglacial age have been recorded in a neighbouring cor e. The ca. 50 m thick till unit above this represents at least two pha ses of glaciation during the Weichselian. The last deglaciation occurr ed at 15 ka. The Troll Field record suggests that some of the Middle a nd Early Pleistocene climatic oscillations attained amplitudes compara ble with those recorded for the Late Quaternary in this region. Howeve r, during the period between ca. 1.1 and ca. 0.6 Ma the Fennoscandian ice sheet did not expand out onto the shelf.