Deciphering a non-glacial/glacial landscape mosaic in the northern Swedish mountains

Relict surfaces contain information on past surface processes and long-term landscape evolution. A detailed investigation of relict non-glacial surfaces in a formerly glaciated mountain landscape of northern Sweden was completed, based on interpretation of colour infrared aerial photographs, analysis in a GIS, and fieldwork. Working backwards from landscape to process, surfaces were classified according to large- and small-scale morphologies that result from the operation of non-glacial processes, the degree of weathering, regolith characteristics, and the style of glacial modification. Surfaces were also compared in the GIS according to elevation, slope angle, and bedrock lithology. The study revealed five types of relict non-glacial surfaces but also two types of extensively weathered glacial surfaces that were transitional to relict non-glacial surfaces, illustrating spatially variable processes and rates of non-glacial and glacial landscape evolution. Rather than being static preglacial remnants, relict non-glacial surfaces are dynamic features that have continued to evolve during the Quaternary. The classification provides hypotheses for landscape evolution that can be field tested through, for example, terrestrial cosmogenic nuclide studies and geochemical analyses of fine matrix materials. The classification may be applicable to relict non-glacial surfaces in other formerly glaciated landscapes.