Palaeomagnetism of the Late Precambrian Vadsø and Barents Sea Groups, Varanger Peninsula, Norway

Abstract

Abstract A palaeomagnetic study has been made on Neoproterozoic rocks from the Varanger Peninsula, northernmost Norway. Several of the formations studied contain a stable magnetization of diagenetic origin. Two main groups of directions were obtained; one (A) with a steep southeasterly positive direction, the other (B) with a shallow northern direction. The Group A direction is not in accordance with the stratigraphic age of the rocks and the Fennoscandian apparent polar wander path; hence it may reflect a remagnetization. The Group B direction yields a Late Riphean-Early Vendian palaeopole at 24°N, 207°E (dp=5°, dm=11°, N=11) in good agreement with data from contemporary rocks of the Kola Peninsula. The Varanger Peninsula is transected by the Trollfjord-Komagelv Fault which divides the peninsula into the allochthonous Barents Sea Region and the autochthonous Varangerfjord Region. Previous palaeomagnetic studies have suggested that the Barents Sea Region has moved 500 to 1000 km to its present position. This study indicates that the movement has been less than 250 km which is in better agreement with geological information.