The structure of the post-Caledonian strata within the West Spitsbergen Fold Belt is dominated by a Palaeogene compressive tectonic event, though earlier deformation also is documented. The Sørkapp-Hornsund area shows abundant evidence for the nature and the relative ages of these events. A multiphase tectonic history can be devised with implications for the post-Caledonian tectonic history of Svalbard.
The majority of these movements are related to a defined zone of weakness within the basement, here called the 'Sørkapp-Hornsund mobile zone'. It comprises, besides other structures, the previously defined Carboniferous 'Inner Hornsund Fault Zone' and the southern part of the 'Tertiary fold-and-thrust belt'. This mobile zone is supposed to be one of several long-lived tectonic lineaments that have controlled the tectonic development of Svalbard. The pre-existing orientations of these lineaments are thought to be responsible for apparent disagreements between regional stress fields and modes of deformation.
W. K. Dallmann, Norsk Polarinstitutt, P.O.B. 158, N-1330 Oslo Lufthavn, Norway.