Weichselian sediment succession at Ruunaa, Finland, indicating a Mid‐Weichselian ice‐free interval in eastern Fennoscandia

Abstract

Core material obtained from three boreholes was studied from the Ruunaa area, Finnish northern Karelia, in order to reveal the Late Pleistocene environmental history of eastern Finland. Conventional litho-and biostratigraphical methods were used and suitable sediment samples were dated using quartz optically stimulated luminescence. The results indicate that two till units were deposited by two separate Weichselian ice advances into the area. The first advance took place prior to 52 kyr ago, most likely during the early Middle Weichselian, while the second is thought to have taken place during the Late Weichselian after 25 kyr ago. The sediment succession at Ruunaa therefore indicates a Middle Weichselian ice-free period around 50-25 kyr ago in the eastern part of Fennoscandia.

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

“…These sites suggest close to ice-free conditions during at least parts of MIS 3 (Helmens et al, 2000(Helmens et al, , 2007(Helmens et al, , 2009H€ attestrand, 2007;Ukkonen et al, 2007;Lunkka et al, 2008Lunkka et al, , 2015Salonen et al, 2008;Alexanderson et al, 2010;Helmens and Engels, 2010;H€ attestrand and Robertsson, 2010;Wohlfarth, 2010;Wohlfarth and N€ aslund, 2010;Wohlfarth et al, 2011;M€ oller et al, 2013), mapwise summarised in Mangerud et al (2011;Fig. 22.5).…”

Late Pleistocene and Early Holocene Climate of Ny-Alesund, Svalbard (Norway): A Study based on Biological Proxies

“…Ice free conditions in Sweden and northern Finland during an early part of MIS3 were also reported by Helmens et al (2007a, b) and Hättestrand (2008). Recent work by Lunkka et al (2008) also points to similar conditions in eastern Finland between around 50 and 25 kyrs. These accounts provide some regional climatic conditions supporting our inferences.…”

Reconstruction of palaeoinfiltration during the Holocene using porewater data (Laxemar, Sweden)

“…Recent climate data from Finland, Norway and Sweden, however, suggest that at least during parts of MIS 3 ice-free conditions prevailed in southern and central Sweden (e.g. Helmens et al, 2007;Ukkonen et al, 2007;Lunkka et al, 2008;Hättestrand and Robertsson, 2010).…”