Methods and stratigraphies used to reconstruct Mid- and Late Weichselian palaeoenvironmental and palaeoclimatic changes in Norway.

Abstract

A review is presented on the comprehensive stratigraphic database and the methods used for palaeoclimatic and palaeoenvironmental interpretations in Norway during the Mid- to Late Weichselian time interval. The reconstructions are based on 9 transects from inland to coast and are underpinned by more than 300 dates, which provide a coherent chronology of the stratigraphic successions and of the main events. Raised marine sediments suggest that considerable glacial isostasy combined with ice-sheet instability affected several area, the sea reaching far inland during phases of significant ice retreat dated to between 45 and 17 ka (14c) BP. Magnetic susceptibility records obtained from paleosols proved useful both as a tool for correlation and as a palaeoprecipitation indicator, a parameter that is notoriously difficult to estimate. These data, in combination with biostratigraphic information (animal bones, shells, dinoflagellates, pollen, macro plant remains, etc), suggest tentatively that the climatic conditions during the interstadials between 45 and 17 ka (14C) BP varied between dry low and middle Arctic, dry subarctic tundra to more humid subarctic, and Boreal conditions during the older part of this interval.