Neoglaciation and an early 'Little Ice Age' in western Norway: lichenometric evidence from the Sandane area

Abstract

Moraine sequences, protalus ramparts, rock glaciers and various slope deposits in seven separate glacier basins provide lichenometric ages for glacier retreat in an upland area of Sogn-og- Fjordane, southern Norway. Geomorphological mapping, relative dating based on section Rhizocarpon size-frequency distributions, observations on vegetation cover, and numeric dating based on a regional lichen dating curve for section Rhizocarpon, place moraines into three groups: Stage 1 moraines of likely Preboreal or Younger Dryas age; Stage 2 moraines of pre- or early 'Little Ice Age' but post-Preboreal age (thirteenth-fourteenth centuries); and Stage 3 moraines of fifteenth-century age and younger. The occurrence of thirteenth-sixteenth century (pre- or early 'Little Ice Age') moraines at low altitudes in the Sandane area is thought to relate to greater availability of moisture and to the capture of wind- drifted snow. These moraines are some of the oldest 'Little Ice Age' moraines dated by lichenometry in southern Norway. In some cirques, glaciers retreated from their fifteenth-century positions allowing protalus rampart development, scree accumulation and debris-flow activity to continue until the present.