Baltic Ice Lake

Country:

Sweden

Region:

south-western Sweden

Lake type:

proglacial lake

Category: clastic varves

Elevation:

76 m asl

Archive type:

marine sediments

Author of images:

Mark Johnson

Reference:

Johnson, M.D., Kylander, M.E., Casserstedt, L., Wiborgh, H., Björck, S., 2013. Varved glaciomarine clay in central Sweden before and after the Baltic Ice Lake drainage: a further clue to the drainage events at Mt Billingen. GFF, 135: 293-307.

Link to reference or DOI:

http://dx.doi.org/10.1080/11035897.2013.819032

Drainage event of the Baltic Ice Lake (BIL) sediment recorded in varved clay, southwest Sweden. Digital photograph of the split core-surface (top is right). The core is 70 cm long. Two large arrows mark sand layers representing the drainage of the BIL. At this site near Götene the recently deglaciated land was covered with ocean water of water depth of 50 m. The drainage event marked the end of the Baltic Ice Lake and the beginning of the Yoldia Sea. These sand layers, only 15 km from the site of the drainage, indicate that the sedimentary record of the drainage is minimal compared to the magnitude of this event. The smaller black arrows represent the tops of marine varves deposited prior to drainage, the grey arrows represent the varve tops after drainage. There is a distinct change in colour and composition of the marine varved clays before and after the event caused due to profound hydrographic changes after the drainage. Prior to drainage, all fresh water in the Baltic basin exited through the Danish Straits. After the drainage, all fresh water exited through central Sweden, which is where this core was taken. The significance on this site is that it represents one of the few recently discovered localities that preserve the drainage sediment in a stratigraphic sequence. > max. resolution