The Local Last Glacial Maximum of the southern Scandinavian Ice Sheet front: Cosmogenic nuclide dating of erratics in northern Poland

Abstract : This paper presents new results of terrestrial cosmogenic nuclide dating of erratics in northern Poland. We report the first exposure ages of erratics located on the pre-Local Last Glacial Maximum and the Local Last Glacial Maximum moraines in Poland. Published radiocarbon ages are calibrated and used as a background indicator of the possible time window for the Local Last Glacial Maximum. The terrestrial cosmogenic nuclide exposure ages presented in this study indicate that: (1) exposure ages of erratics located on the pre-Local Last Glacial Maximum moraines (15.9 +/- 1.4 to 101.7 +/- 8.5 ka) are not clustered around any specific time interval, (2) the age of the ice sheet retreat from the Local Last Glacial Maximum ice limit in western Poland is 20.7 +/- 0.8 ka and the probable duration of the Local Last Glacial Maximum in western and central Poland is between similar to 25 ka and similar to 21 ka, (3) the age of the ice sheet retreat from the Local Last Glacial Maximum ice limit in eastern Poland is 17.3 +/- 0.5 ka and the probable duration of the Local Last Glacial Maximum in eastern Poland is between similar to 22 ka and similar to 18 ka. Our results show that the Local Last Glacial Maximum ice limit in western and central Poland is probably similar to 3 ka older than in eastern Poland.