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

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 sedim...

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Bibliographic Details
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
Description
Summary: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.

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