The deformational structures of the deposits on the Höfdabrekkujökull forefield, Mýrdalsjökull, Iceland

The deformational structures of the developing subglacial (a) substratum deposits and the near Höfdabrekkujökull forefield (b) are the characteristic dynamic parts of the glacio-sedimentological system. These occur in different geomorphological situations: a) under sandur deposits, on the periphery of the fossil embankment of the frontal moraine, on both its distal and proximal slopes, and in the backside depression of this form and b) within the dead ice kettle which was formed in the surface part of the fluvioglacial deposits of the VI sandur level. The older, sub-sandur glaciotectonic discordances, which occur below sandur deposits, represent dynamic structures of two separate glacial advances. Independently of these, deformations of gravitational type also occur. In contrast, the deformations of melt-denudational deposits of the dead ice kettle, surrounded by fluvioglacial deposits, belong to younger (at least several tens years) distortions of gravitational type.