PERIGLACIAL PATTERNED-GROUND ON THE STYGGEDALSBREEN GLACIER FORELAND,JOTUNHEIMEN, SOUTHERN NORWAY - MICRO-TOPOGRAPHIC, PARAGLACIAL AND GEOECOLOGICAL CONTROLS

Several types of periglacial patterned ground have developed rapidly i n the frost-susceptible sediments of degraded 'annual' moraines deposi ted between c. AD 1930 and 1973 on the glacier foreland of Styggedalsb reen, western Jotunheimen, Norway. Detailed mapping of patterned groun d phenomena provides the basis for a micro-scale, landscape-ecological (geoecological) approach to the distribution, formation and stabiliza tion of patterned ground. Sorted nets, sorted stripes, surface cracks, solifluction lobes, boulder-cored frost boils, ploughing boulders, an d surficial colluvial sand and gravel deposits occupy distinct micro-t opographic site types influenced by slope, exposure, drainage conditio ns and vegetation. Moisture availability appears to be the most import ant physical environmental control on both the distribution of the pat terned ground and present levels of activity. Patterned ground formati on and stabilization on glacier forelands are seen as partly exogenous and paraglacial, rather than entirely endogenous and developmental. V egetation development can be a cause or an effect in the formation of particular types of patterned ground which, even in relatively simple glacier-foreland landscapes, may involve complex geoecological interac tions. (C) 1998 John Wiley & Sons, Ltd.