Topographic and bioclimatic controls on soil/paleosol morphogenesis in the Norra Storfjنllet Mountains, Sweden

Retreat of the Stabre Glacier in the Norra Storfjället Mountains of northern Sweden led to the emplacement of a broad expanse of glaciofluvial sediment, a virtual blanket of debris interspersed with recessional and push moraines. Episodic mass wasting of the glaciofluvial, moraine and loessic deposits yielded a pedostratigraphic succession of 14C-dated sub-Boreal and sub-Atlantic Cryosols in soliflucted sediment that provide weathering data related to Neoglacial perturbations, whereas weathering within polygonal complexes yielded single profile, one event, Cryosolic Gleysols of similar age. Both provide a database of paleosol extremes controlled by topography and bioclimate. Together, the paleosols provide a database of weathering of mixed amphibolitic gneiss, trachytic lavas and granite weathering under two variable redox conditions, one (soliflucted sediment) fully or partially aerated and free draining under a subaerial atmosphere with high redox potential; the other (polygonal soil) partly reduced under the influence of an active layer of sporadic permafrost. Paleosols dated to the Early Neoglacial (~ 3600–4200 cal 14C yr BP) have variable horizon development dependent upon landform associations, and provide maximum ages for the second oldest moraine stillstand of ice retreat into the highlands on the Arctic Circle of Sweden. The Cryosolic Gleysol yields surprisingly high extractable Fe and Al suggestive of considerable redox fluctuations over the time of morphogenesis.