There are two types of patterned ground. There are small dome shaped polygons and stripes due to frost sorting and there are large polygons with raised edges due to frost wedging/ice contraction. The first type, existing due to the process of frost sorting, is a result of the heave/thrust of stones to the surface, causing surface sediments to be up domed, followed by surface sorting. This occurs on slopes of less than 6º, and the polygons can be 1-5m in diameter. Elongated stripes are formed on slopes with a gradient over 6º. In autumn and winter, ice layers form in ...