A ¹⁰Be‐based reconstruction of the last deglaciation in southern Sweden

Abstract

We present 23 cosmogenic surface exposure ages from 10 localities in southern Sweden. The new 10Be ages allow a direct correlation between the east and west coasts of southern Sweden, based on the same dating technique, and provide new information about the deglaciation of the Fennoscandian Ice Sheet in the circum‐Baltic area. In western Skåne, southernmost Sweden, a single cosmogenic surface exposure sample gave an age of 16.8±1.0 ka, whereas two samples from the central part of Skåne gave ages of 17.0±0.9 and 14.1±0.8 ka. Further northeast, in southern Småland, two localities gave ages ranging from 15.2±0.8 to 16.9±0.9 ka (n=5) indicating a somewhat earlier deglaciation of the area than has previously been suggested. Our third locality, in S Småland, gave ages ranging from 10.2±0.5 to 18.4±1.6 ka (n=3), which are probably not representative of the timing of deglaciation. In central Småland one locality was dated to 14.5±0.8 ka (n=3), whereas our northernmost locality, situated in northern Småland, was dated to 13.8±0.8 ka (n=3). Samples from the island of Gotland suggest deglaciation before 13 ka ago. We combined the new 10Be ages with previously published deglaciation ages to constrain the deglaciation chronology of southern Sweden. The combined deglaciation chronology suggests a rather steady deglaciation in southern Sweden starting at c. 17.9 cal. ka BP in NW Skåne and reaching northern Småland, ∼200 km further north, c. 13.8 ka ago. Overall the new deglaciation ages agree reasonably well with existing deglaciation chronologies, but suggest a somewhat earlier deglaciation in Småland.

Drumlinised glaciofluvial and glaciolacustrine sediments on the Småland peneplain, South Sweden – new information on the growth and decay history of the Fennoscandian Ice Sheets during MIS 3

“…M€ oller (1987, 2010) and Bj€ orck and M€ oller (1987) interpreted the integrated, east-to west-trending zone of hummocky and ribbed moraine as evidence for large-scale, gradual ice stagnation once the ice recession reached above the highest shoreline in northern Skåne and Blekinge. They correlated this geomorphic zone and glacial event to the ice-margin oscillation and build-up of the G€ oteborg Moraine on the Swedish west coast (see above), a correlation that also fits well with recently performed cosmic nuclide (CN) dating, both within the G€ oteborg Moraine proper and within the hummocky moraine zone (Anjar et al, 2014a). Also, the boundary with the streamlined terrain to the north is interpreted to represent a preserved palaeo-thermal boundary; to the south of it was the last area of basal freeze-on, debris over-loading and stagnation of ice, and to the north of it was wet-based conditions with stream-lined terrain formation, including erosion/deformation of pre-existing older sediment (M€ oller, 2010;M€ oller and Dowling, accepted).…”

Regional deglaciation and postglacial lake development as reflected in a 74 m sedimentary record from Lake Vättern, southern Sweden

“…The Levene line is dated to , 13.8-13.4 cal. ka BP (Lundqvist & Wohlfarth 2000;Larsen et al 2012;Anjar et al 2014) and the Skövde line is dated to , 12.2 cal. ka BP (Lundqvist & Wohlfarth 2000).…”

“…This is likely the same readvance described by Waldemarson (1986) as the Ö xnehaga readvance, which stretched , 7 km south of lake Vättern leaving a subglacial till overlying proglacial clays and glaciofluvial sediments (cf Greenwood et al, in press). According to the approximate varve counting, the ice readvance is contemporaneous with the terrestrial Levene readvance at , 13.6 ka BP (Berglund 1979;Lundqvist & Wohlfarth 2000;Larsen et al 2012;Anjar et al 2014). …”

“…Dating along the Levene ice marginal line indicates ages between , 13.8 -13.4 cal. ka BP (Lundqvist & Wohlfarth 2000;Larsen et al 2012;Anjar et al 2014) and implies that the Late Weichselian ice sheet margin was located at the southern tip of Lake Vättern around this time.…”

Discriminating between subglacial and proglacial lake sediments: an example from the Dänischer Wohld Peninsula, northern Germany

“…After the fourth advance ice retreated offshore of the D€ anischer Wohld Peninsula before re-advancing out of the eastern Baltic Sea (over the study site) and terminating several kilometres south of the present shoreline (Mecklenburg Phase, Young Baltic Advance; Stephan, 1995Stephan, , 2001. Final retreat of ice out of northern Germany is thought to have occurred after~19 ka BP (Lüthgens et al, 2011;Houmark-Nielsen et al, 2012), and possibly as late as 15 ka (Preusser, 1999), although this conflicts with deglacial chronologies further north, which suggest the ice margin reached southern Sweden between 18 and 16 ka BP (Lundqvist and Wohlfarth, 2001;Anjar et al, 2014).…”