THE STRUCTURAL GLACIOLOGY OF KONGSVEGEN, SVALBARD, AND ITS ROLE IN LANDFORM GENESIS

Mapping of the structural glaciology of Kongsvegen, Svalbard, reveals evidence for four main deformational structures. These are stratificat ion, longitudinal foliation, thrusts and crevasse traces. These struct ures are considered in terms of their contribution to debris entrainme nt, transport and subsequent landform development. Stratification is a ssociated with small amounts of supraglacial debris that has been fold ed with flow-parallel axes longitudinal foliation in places incorporat es basal glacial sediments along folds with flow-parallel axes; and th rusts transport basal debris to the glacier surface. Crevasse traces a re not significant in terms of debris entrainment. The entrainment of basal debris along longitudinal foliation is not a universally recogni sed process. At Kongsvegen this process is attributed to the developme nt of a transposition foliation, in combination with incorporation of debris-rich basal ice or soft basal sediment in the fold complex. Mapp ing of the landforms in the proglacial area shows that debris incorpor ated along longitudinal foliation is released as ''foliation-parallel ridges'' and that transverse ridges mark debris-bearing thrusts. The r ole of longitudinal foliation in landform development has never been d ocumented in this manner. Although the preservation potential of such ridges may be limited, recognition of foliation-parallel ridges in the Pleistocene landform record has important implications for the interp retation of the dynamics of former ice masses.