Englacial kames near Jeziorany (Warmia — western Masurian Lakeland, Poland): Morphology, internal structure and origin

Groups of hills on a regional Vistulian (Weichselian) deglaciation plateau (Warmia, NE Poland) are covered by till of up to a dozen metres thick. It is the same till of the main stadial of the Vistulian glaciation that outcrops in the upland. The internal parts of the hills consist of fine-grained sands. These glacial landforms are referred to as englacial kames; they result from infilling of englacial caverns with sand. The orientation of the kame fields and the form pattern within these fields coincide with the system of primary crevasses in the ice, as it was reconstructed on the basis of the orientation of postglacial crevasse forms. The origin of the englacial caverns at crossing points of crevasse surfaces in the glacier is discussed. Structural analysis (relationship with a circular lineament, local differentiation of the complete profile of the Pleistocene deposits, possibility of occurrence of faults — festoon glacitectonics) suggests that the origin of these landforms is related to movements in the substratum.