Geomorphological aspects of glaciation in the Oldřichov Highland, Northern Bohemia, Czechia

Abstract

The Oldrichov Highland was glaciated during the Middle Pleistocene as evidenced by the proglacial sediments in the valley of the Jerice River at Mníšek near Liberec. These sediments are a relic of a glaciofluvial terrace which accumulated in front of a small lobe of an ice sheet. Ice sheet mass advanced from north against northern face of the Oldrichov Highland. The southerly advancing ice lobe pushed through Oldrichov Col (478 m) and terminated ~ 400-500 m to the south of the col. The maximum thickness of the glacier to the north of the col was 50-60 m, in the col area it was < 10 m. Clast petrology varies up section in the glaciofluvial sediments with the predominance of local and near rocks together with quartz clasts of mainly near origin. Lower amount of nordic material (below 8 %) was influenced by the local relief. Nordic erratic pebbles show the predominance of central and southern Swedish and east Baltic crystalline rocks and Cretaceous and Paleocene flints. The maximum extent of the glaciation was reconstructed by numerous sedimentological and geomorphological methods with sufficient accuracy.