Mount Ślęża—The Highest Inselberg in the Sudetic Foreland and Its Glacial-Periglacial Morphogenesis

Mt. Ślęża is a striking landmark of the Sudetic Foreland in SW Poland, rising as a distinctive inselbergInselberg more than 500 m above the surrounding lowlands. It is part of a larger basement massif (Ślęża Massif) characterized by a complex geological structure, which consists of metamorphic rocks (gabbroGabbro, serpentinites, amphibolites) included in the Palaeozoic ophioliteOphiolite structure and late Carboniferous granitoidsGranites, granitoides. Main relief features of the Ślęża Massif were shaped as a result of long-term divergent weathering in the warm climatic conditions of the Mesozoic and most of the Cenozoic. Mt. Ślęża existed in a form similar to the present-day one in the Miocene, as testified by the occurrence of Middle Miocene clays, silts, sands, and lignite on weathered rock-cut surfaces around the massif. Its further morphogenesis in the Pleistocene involved at least two transgressions of the Scandinavian ice sheetIce sheet and the influence of the periglacialPeriglacial environment. During the maximum extent of the inland glaciation the hilltop of Mt. Ślęża remained as a nunatakNunatak, but glacial erosionErosionglacial occurred on the lower slopes. In the younger phase of the Saalian glaciation and during the Weichselian glaciationGlaciationWeichselian (Vistulian), the slopes of the Ślęża Massif were modelled by periglacial processes. CragsCrag, frost-riven cliffs, extensive blockfieldsBlockfield (block field), solifluctionSolifluction mantles, and congelifluction block tongues, descending to ca. 250 m asl, were formed. Probably soon after the decay of the last ice sheet, as a result of mass movementsMass movement in a paraglacial environment, large block tongues similar to rock glaciersRock glacier were formed on the southern and eastern slopes of Mt Ślęża. The diversity of periglacialPeriglacial relief, combined with other natural and cultural values, makes Mt. Ślęża an important element of European heritage.