14. Jizerské Hory—an Interplay of Rock Control, Faulting and Inland Glaciation in the Evolution of a Granite Terrain

The granite massif of Jizerské hory in the northern part of the Czech Republic is an excellent area to examine different controls on the geomorphic evolution, acting over a long time scale. A protracted period of denudation in the early Cenozoic was followed by uplift and tilting of the plateau to the south in the Neogene. In consequence, the subdued upland topography is truncated by a steep, fault-generated escarpment from the north, incised by valleys with bedrock and boulder-filled channels. Characteristic medium-size landforms include tors and crags of multiple shapes, boulder blankets, waterfalls, whereas weathering pits and other forms of microrelief typify many exposed granite surfaces. In the Pleistocene the Scandinavian ice sheet reached the footslopes of the mountains and remodelled bedrock elevations into roches moutonnées. Very small glaciers may have existed on lee-slopes of upland elevations, fed by snow blown-in by westerly winds. Torrential floods and occasional debris slides and flows are main geomorphic processes acting nowadays.