Morfología periglacial del volcán Llullaillaco (Chile/Argentina)

Abstract

The periglacial processes in the High Andes and resulting periglacial phenomena are presented here by example of Mt. Llullaillaco, at 24°43’ S and 68°32’W, on the frontier between Argentina and Chile. The landforming processes reflect the recent and present extremely arid climate as well as the different age of the volcanics. The range of periglacial landforms, the vertical distribution and association that are described here, result from the interactions of climate and bedrocks. The upper periglacial limits are the highest of the world. The identified phenomena allow to differentiate between the subandine (below 4,100 m), subandine/andine (4,100-4,300 m), andine (4,300-4,700 m), lower periglacial (4,700-5,800 m), medium periglacial (5,800-6,300 m) and upper periglacial (6,300-6,739 m) altitudinal zones. Due to the extreme aridity glaciers cannot form today. Their absence therefore is not due to insufficiently low temperatures, but to lack of humidity.