Neotectonics, sea-level changes and biological evolution in the Fennoscandian Border Zone of the southern Kattegat Sea

• Published in: Boreas Vol. 31; no. 2; pp. 133 - 150
• Main Authors: Jensen, Jørn Bo, Petersen, Kaj Strand, Konradi, Peter, Kuijpers, Antoon, Bennike, Ole, Lemke, Wolfram, Endler, Rudolf
• Format: Journal Article
• Language: English
• Published: 01.06.2002
• Subjects: Marine; ANE, North Sea, Kattegat; Fennoscandia
• ISSN: 0300-9483
• DOI: 10.1080/030094802320129944

Shallow seismic data and vibrocore information, sequence stratigraphic and faunal evidence have been used for documentation of Late Weichselian reactivation of faulting in the south central Kattegat, southern Scandinavia. The study area is situated on the Fennoscandian Border Zone, where tectonic activity has been recurrent since Early Palaeozoic time and still occurs, as shown by present earthquake activity. New data from the area south of the island of Anholt show that after deglaciation fast isostatic rebound resulted in reactivation of a NW-SE striking normal fault system. This tectonic episode is dated to a period starting shortly before 15.0 cal. ka BP and ending around 13.5 cal. ka BP, after regression had already reached a level of about 30 m b.s.l. The vertical displacement associated with the faulting was in the order of 20 m. More generally, the results support the previously reported late Weichselian sea-level highstand, which was followed by forced regression until the eustatic sea-level rise surpassed the rate of glacio-isostatic rebound in early Preboreal. Our findings further imply that drainage of the Baltic Ice Lake through the Oeresund at c. 15 cal. ka BP may have been triggered by tectonic activity in this region.