Osuwiska Masywu Ślęży (Przedgórze Sudeckie)

Abstract

Landslides on the Ślęża Massif (Sudetic Foreland).A b s t r a c t. Ślęża Massif is an isolated group of hills, surrounded by plains, located on the Sudetic Foreland with the main tops of OElê¿a and Radunia. This mesoregion covers an area composed of two structural units: Sudetic Ophiolite and Strzegom-Sobótka Granite Pluton. The present relief of the Ślęża Massif was formed mainly during the Pleistocene glaciations. This article presents the results of landslide observations made in selected locations on the Ślęża Massif. Scientific works were carried out on the south western, southern and eastern slopes of Ślęża (composed of gabbros), as well as on the northern slopes of Radunia (serpentinites). This area is the place of occurrence of specific morphological forms with research history abundant in various concepts (among others: moraines of the Scandinavian ice sheet, congelifluction tongues, debris flows, fossil rockglaciers and landslides). Author’s research, based on field works and digital terrain model analysis, reveals that 15 inactive landslides exist at these locations. The forms are characterized by various morphometric parameters and different types of colluvial mass movements. Probably, they emerged as a result of late Pleistocene and early Holocene climate changes. Author’s conclusions partially confirm some observations and interpretations stated by Horwath in 1981 and by Traczyk and Kasprzak in 2014. Due to plenty of landslide evidence, the views about relict rock glaciers and other conceptions should be defined as incorrect. The forms require further detailed studies.