Lichenometric Dating of Moraine Ridges in Northern Norway: Some Problems of Application

ABSTRACT

A lichenometric growth curve has been derived for the area immediately to the south of the Svartisen ice caps in northern Norway. The curve indicates that lichen growth is considerably faster than postulated in earlier studies in the area. The curve has been applied to a well-developed sequence of moraine ridges at Blokkfjellbreen, an outlet glacier of Vestisen, Svartisen. Lichenometry correctly predicts the approximate margin of the glacier in 1910 A.D., but fails to predict the 1945 A.D. marginal position. There is evidence that several other predicted dates for the ridges are incorrect, and the value of the technique at this site is questioned. Differences between the results obtained in this study and those in earlier studies are explained in terms of differences in the sampling framework, litho- logical variations in the lichen growth rate, altitudinal differences and the potential errors involved with using ¹⁴C dated surfaces and mine spoil heaps as fixed points for the development of a lichenometric growth curve.