Ice recession and depositional environment in the Blekinge archipelago of the Baltic Ice Lake

Abstract

The Swedish varved clays, deposited in the former Baltic Ice Lake during the deglaciation, constitute an excellent tool to decipher the ice recession with annual precision. New clay varve diagrams from Blekinge, southern Sweden, enable to place the deglaciation of sites situated in northern Blekinge between the local varve years ‐39 to +77, which preliminary corresponds to 12,971–12,855 v.y. BP. Detailed and systematic investigations demonstrate, that plant macrofossils can be found in the varved clays, if suitable sites, close to the former shoreline of the Baltic Ice Lake are chosen. In Blekinge the coastline formed an archipelago‐like landscape with small, deep, incised fjords and numerous islands similar to today's. In‐wash of organic matter in near shore areas, commenced with the beginning of the B⊘lling warming peak (c. 12,800–12,700 v.y. BP) and is reflected by the relatively higher amount of macroscopic plant and animal remains. In varved clays deposited during the Older Dryas stadial (<12,700 v.y. BP) considerably less macroremains were recorded, probably due to less melt water out‐flow and/or change in the vegetation.

Wohlfarth, B., Björck, S., Holmqvist, B., Lemdahl, G. & Ising, J., 1994: Ice recession and depositional environment in the Blekinge archipelago of the Baltic Ice Lake. GFF, Vol. 116 (Pt. 1, March), pp. 3–12. Stockholm. ISSN 1103–5897.

Keywords:

• Late Weichselian
• varved clay
• ice recession
• varve chronology
• Swedish Time Scale
• macrofossils
• Blekinge