The last Fennoscandian Ice Sheet glaciation on the Kola Peninsula and Russian Lapland (Part 2): Ice sheet margin positions, evolution, and dynamics

The pattern, style, and timing of glaciation of the last Fennoscandian Ice Sheet (FIS) on the Kola Peninsula and Russian Lapland (northwest Arctic Russia) is widely debated. This is due, in part, to the lower-resolution empirical data used in previous investigations. In this paper, we present an ice margin reconstruction, an updated database of previously published numerical ages, and a new time-slice reconstruction. The reconstruction, which is presented across a series of 10 maps, documents the spatial evolution of the ice sheet every 1000 years between 16 and 11 ka, and for four selected time periods back to 29 ka (19-17, 21-20, 25-22, and 29-26 ka).

Our reconstruction indicates that the Kola Peninsula and Russian Lapland was probably ice-free prior to the advance of the FIS c. 29 ka. The FIS reached its maximum lateral extent in northwest Arctic Russia c. 19-17 ka, later than many other sectors of the ice sheet. This disparity probably arises as a result of both the topography of Fennoscandia and the position of the Kola Peninsula and Russian Lapland in a precipitation shadow of the Scandinavian Mountains. Thus, FIS glaciation in northwest Arctic Russia was strongly influenced by a fluctuating climate. Most of the FIS in northwest Arctic Russia was terrestrial-based, although marine-terminating margins existed in the fjords of northern Russian Lapland. The retreat of the White Sea lobe was probably not influenced by marine transgression until c. 12 ka because palaeo-sea levels during most of the Late Weichselian were considerably lower than present, and a shallow sill in the Mouth of the White Sea would have inhibited ocean waters entering the White Sea basin. Instances of ice margin readvance during deglaciation are also apparent, including a significant readvance of the White Sea lobe c. 14 ka. This study presents the first reconstruction grounded in high-resolution empirical data for the Kola Peninsula and Russian Lapland, and is presented in a time-slice format that is of critical importance for testing and validating numerical ice sheet and climate models.