Periglacial micro-relief in the subnival zone of Kazbek

Abstract

During an expedition to the Caucasus in August 1957, small periglacial landforms were observed on the eastern slope of Kazbek, in the area between the Terek Valley and the Gergeck Glacier, at altitudes of 1800–3600 m a.s.l. This area represents a typical high-mountain volcanic-glacial terrain, with volcanic rock cover and layers of fluvial sediments. The climate of the Central Caucasus combines features of the dry, subtropical climate of Transcaucasia with those of the temperate high-mountain climate. In the zone influenced by cryofracturing and needle ice, various forms of periglacial microrelief develop (including mounds, turf-like forms (tufurs) and patterned soils) that are influenced by vegetation, moisture, frost action and wind erosion. It was concluded that contemporary cryofracturing occurs on scree slopes and rock outcrops, while mound and patterned soil forms result from both frost processes and soil desiccation under conditions of high temperature amplitudes and strong radiation. Observations confirm the significance of geomorphological, climatic and soil conditions for the development of fine periglacial relief in the high regions of Kazbek.