Book Description

The distribution and characteristics of periglacial landforms in the southern Kenai Mountains, Alaska, were investigated during the summer of 1979. The principal area of study was a 1300-metre high mountain mass which stood as a nunatak during the last general glaciation. Periglacial features in the area include gelifluction lobes, nivation hollows, cryoplanation terraces, tors, a string bog, and various forms of patterned ground such as sorted circles, sorted polygons, earth hummocks, sorted steps, sorted stripes, and small ice-wedge polygons. Ground temperature measurements indicate that permafrost recently existed in the area but is no longer present. The sorted polygons, cryoplanation terraces, and nivation hollows are relic features which have been inactive for a considerable time. The turf-banked sorted steps and large gelifluction lobes were active until the very recent thawing of permafrost. Cryofraction and frost sorting still are vigorous active processes. Finely jointed bedrock, a previous colder environment, and long exposure in the absence of glacial ice has allowed periglacial processes to be the dominant surface agents both in the principal study area and in similar areas along the western side of the Kenai Mountains. (Author).