Could long valley glaciers have been extended in the Bohemian Forest? Geophysical insights from Großer Rachel region

Abstract

The Bohemian Forest was glaciated during Pleistocene cold periods. However, opinions on the extent of the glaciation of this mountain range are divided and vary throughout the scientific communities on either side of the Czech/German border. There is the hypothesis of a more extensive glaciation, which is to some extent supported on the Bavarian side, but Czech researchers rather incline to the existence of individual cirques or small valley glaciers. We present the results of geophysical analyses using electrical resistivity tomography carried out in the vicinity of Kleiner Rachelbach cirque. The aim was to examine the extent of the glacial sediments and thus, prove or disprove the hypothesis of a more extensive glaciation. We were seeking to find geophysical manifestations of the glacial sediments (determined on the basis of a literature review, the official geological map and our research) in a moraine complex and beyond it, where long valley glaciers are assumed to have extended. We observed such a manifestation only in the moraine complex. We can thus disprove the hypothesis of an extensive glaciation in the vicinity of Kleiner Rachelbach cirque.