In Swedish the word ås commonly refer to eskers, a glacial landform, but in the case of Söderåsen it corresponds to a tectonic landform called horst. The last glacial ice sheet, the Weichsel ice, left the area of Söderåsen 14,000 to 13,500 years BP. Following this there was a period up to 12,700 years BP of cold non-glacial conditions with permafrost and strong winds.