Abstract

Morpho-tectonic lineaments are deduced from detailed bathymetric maps of the region of Svalbard and the northernmost part of the Atlantic Ocean from onshore geology and from marine geophysical data. Most of the important structural lines known on land can be traced on the fjord bottoms and out onto the shelf areas.

Some results achieved in the present study of the fjord and shelf areas are: a better understanding of the complex graben-horst structures along the west coast of Spitsbergen; the discovery of a NNW - SSE fault in the middle of Isfjorden; the determination of the southern termination of the Central Spitsbergen Tertiary basin; and discovery of triple ridges, probably old glacial end moraines, in submarine valleys continuous with the larger fjords.

The direction of transform faults is inferred from the magnetic anomaly stripes that flank the Knipovich Ridge, and seafloor movement during the opening of Boreas Sea is reconstructed. Four stages with slightly differing spreading directions are suggested by sharp bends in the transform faults, and the fragmentation of the northwestern margin of the Eurasian plate into micro-plates is deduced from the discordance of certain transform faults. The Knipovich Ridge seems to be located at the symmetric centre of the opening of this part of the ocean.