Ice-free intervals continuing into Marine Isotope Stage 3 at Sokli in the central area of the Fennoscandian glaciations

• Main Authors: Karin F. Helmens, Peter W. Johansson, Matti E. Räsänen, Helena Alex, Kari O. Eskola
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Key words; glacial geology; sediments; stratigraphy; pollen analysis; paleobotany; climate change; interstadial environment; interglacial environment; chronology; Pleistocene; Sokli; Lapland Province; Maaselkä; Peräpohjola; Tulppio; Fennoscandian; Lapland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.462.7821; http://www.geologinenseura.fi/bulletin/Volume79/Helmens_etal_2007.pdf

An unusually long and continuous Late Quaternary sedimentary sequence has been pre-served in a sedimentary basin formed in the Sokli Carbonatite Massif in eastern-central Finnish Lapland. A nearly complete sediment recovery from the central Sokli basin com-bined with palynological results from sediments not earlier recovered and an independent OSL/AMS 14C chronology allow us here to define the Late Quaternary climate-stratigra-phy at Sokli and describe in detail the environmental record. Three interstadial intervals of Weichselian age are distinguished that correlate with MIS 5c, 5a and part of MIS 3 in the marine oxygen-isotope record. The interstadials of MIS 5c and 3 age are here defined as the Sokli and Tulppio Interstadials, respectively. The MIS 5a interstadial is correlated with the Maaselkä/Peräpohjola Interstadials of Finnish Lapland, which previously have been ten-tatively assigned a MIS 5c age. Till beds in the Sokli sequence (deposited during stadials 3– 1) correlate to MIS 5b, 4 and 3/2, respectively. Depositional environments and vegetational changes during the ice-free intervals at Sokli are discussed. The Sokli sedimentary sequence indicates significantly less extensive and more variable ice-cover over Finnish Lapland dur-ing the Weichselian than has been earlier suggested based on the long-distance correlation of litho- and bio-stratigraphic fragmentary evidence.