Glaciation in the surroundings of Prášilské Lake (Bohemian Forest, Czech Republic)

Comprehensive geomorphological and sedimentological analyses confirmed three phases of Würm glaciation in the surroundings of Prášilské Lake and Stará Jímka, in the Bohemian Forest (Šumava Mountains). Glaciations were affected by a steep east-facing slope, by plateaus on the adjacent ridges and by local geological conditions. A small valley glacier (about 2 km long and 50 m thick) occurred during the first phase. In the second phase, a glacier–rock glacier developed, probably based on remnants of the valley glacier. During the last phase glacial activity was divided into Stará Jímka and the stepped cirque of Prášilské Lake. A further shallow (∼ 3 m deep) lake in Stará Jímka was dammed by slope movements after deglaciation (∼ 14 cal. ka BP) and survived until ∼ 4 cal. ka BP. The Late Pleistocene chronology of the Bohemian Forest seems to be related more closely to the Alps than to northern Europe. In the mid-mountains of central Europe, Pleistocene glaciation decreases significantly eastward, because of increasing continentality. The presence of plateaus (deflation areas), around 1300 m altitude, across the approach of westerly winds was important for the development of glaciers in the Bohemian Forest. The termination of glaciation before the Younger Dryas is specific to the Bohemian Forest in comparison with the Vosges and Krkonoše Mountains.