Rare, slow but impressive: > 43 ka of rockslide in river canyon incising crystalline rocks of the eastern Bohemian Massif

Abstract Despite significant progress in understanding the stability of rock slopes, little is known about time scales evolution slow-moving rockslides. The Ledové sluje rockslide Thaya River canyon a unique and infrequent slope failure developed crystalline rocks Variscan orogen Central Europe. Fresh topography with trenches, walls, slided blocks, scree slopes crevice-type caves has attracted generations geologists for more than century, but questions mechanism age have remained unresolved. To address this question, we combined geomorphological research detailed analysis geological structure, electrical resistivity profiling terrestrial cosmogenic nuclide dating (TCN). Our data show that above river undercut bank along planar sliding surface predisposed by NW-oriented gently dipping metamorphic foliation intersected steep fractures faults. Although TCN does not allow determination entire life span rockslide, its scarp NE- to ENE-striking fault was largely exposed Last Glacial during marine isotope stages (MIS) 3 2 between ~ 43 23 ka, suggesting slow gradual or multievent movement rather single catastrophic event. We conclude that, although very rare Europe, rockslides Palaeozoic orogens may leave much longer topographic footprint adjacent Alpine mountain belts.