O odmładzaniu osuwisk w Beskidach Zachodnich

Abstract

The author's attention is focused on the rejuvenation of ancient landslides of various types, and their subsequent transformations landslide rejuvenation depends on the relief and the general structure of shifted rocks. On the ground of erosive rocks mechanics and in the first place of the, degree of their disaggregation, crumbling, intermixing and also of the plasticity of the sliding material the following types of landslides are discriminated. 1) Packet or compact landslides, when the sliding rock masses retain their internal structure, only their appearance being altered by the presence of rock packets. The lowest displaced packets in the final stage crumble into rock debris. 2) Debris or detrimental landslides, when the sliding rocks are subjected to crumbling and fragmentation in to detritus and occasional blocks. The blocks and detritus get intermixed their appearance reminding rock debris. 3) Fluid or trailing landslides, when water saturated rocks yield to crumbling and get intermingled with erosive shoals. Such masses in the course of sliding assume the form of mud brine in its movement behaving like a fluid. Besides these essential types occur complex landslides e.g. packet-detrimental, packet-fluid or either packet- detrimental-fluid. The fluid type is the most apt to be rejuvenated being considerably soaked and of poor sliding masses permeability. Often the surface of rock landslides undergoes rejuvenation as a whole. Packet landslides are the least mobile because cracks in the packets and rock fissures allow water to flow down to the subsurface. The progress of these landslides may be marked by points: landslides of detrimental type are less liable to rejuvenation, those of fluid types are more so than packet landslides.