ORIGINS AND DEFORMATION OF POST-CALEDONIAN SEDIMENTS ON BLOMSTRANDHALVOYA AND LOVENOYANE, NORTHWEST SPITSBERGEN

Unmetamorphosed, post-Caledonian (Devonian) sediments known from Lovenoyane and eastern Blomstrandhalvoya in the Kongsfjorden area of northwest Spitsbergen have been found to be distributed widely over the latter area. The geometry and composition of the sediments indicate synsedimentary fault activity and the present-day topography is a partially exhumed post-Caledonian (Devonian) landscape. N-S striking deformation structures in the sediments and post-metamorphic brittle structures in the basement marbles are consistent with purely E-W compression. These structures are comparable with similarly oriented folds, thrusts and cleavages in the larger Devonian basin of Northern Svalbard. Their orientation, however, contrasts markedly with the north- to northeast-directed fold and thrust structures developed to the south on Broggerhalvoya. Although the structures on Blomstrandhalvoya may represent deformation within the foreland of the West Spitsbergen Fold Belt, an earlier Svalbardian origin cannot be ruled out.