Three distinctly different glacial landscapes can be recognized in northern Fennoscandia. Because they cross-cut it is also possible to resolve the relative age chronology (Plate 38.11). Swarm 1, the oldest, is a classic deglaciation swarm, and includes drumlins, eskers and end moraines, formed by southeastward ice flow emanating from the Scandinavian Mountain Range. This landscape is locally overprinted and reshaped by later ice flow from the Bothnia Bay to the south/south-southeast (Swarm 2). Swarm 2 consists exclusively of glacial lineations, and hence classifies as an event swarm, and is interpreted to have formed during the LGM (Kleman et al., 1997). A deglacial envelope (Swarm 3) overprints both Swarm 1 and 2, and forms a radial pattern leading in towards a final deglaciation centre in the eastern part of the Scandinavian Mountain Range. Most of this deglacial envelope is defined by wet-based flow traces (drumlins) and eskers. However, much of the eastern sector of the deglacial envelope essentially lacks warm-based ice-flow indicators, and lateral meltwater channels form a coherent pattern fanning out towards the east. This indicates that this sector was dominated by frozen-bed conditions during the last deglaciation.
Was this article helpful?