Varved clay chronology as a means of recording paleoseismic events in southern Sweden

Abstract

Structures in bedrock and sediments suggest that the Fennoscandian Shield was subjected to a higher seismicity at the end of the last glaciation than it is today. We suggest that the annual varves of the glacial clays document this seismicity. In the Stockholm area, three paleoseismic events have so far been recorded in the varved clay chronology. Liquefaction structures have also been documented. The occurrence of heaps of ‘sharp-edged blocks’ (large caves in crystalline bedrock) might be another sign of this seismicity.