PRESERVATION OF LANDFORMS UNDER-ICE SHEETS AND ICE CAPS

This article addresses the question of whether or not distinct glacial and non-glacial landforms can survive beneath ice sheets and ice caps with little or no morphological alteration. A review of recent work documents the existence of pre-last stadial landforms and landscapes in areas covered by the Fennoscandian and Laurentide ice sheets. A substantial number of independent works indicate that landforms such as eskers, drainage channels and boulder fields have escaped destruction despite complete ice overriding during several tens of millenia. Full preservation of former ground surfaces or delicate landforms probably is linked to areas where the ice-sheet base was continuously frozen to its bed. Larger ''robust'' landforms, such as large drumlins, appear to have been preserved even under wet-based conditions. In glaciated areas, patches preserved under dry(cold)-based conditions provide important windows towards the past, showing landscapes that were destroyed in surrounding areas affected by wet-based and eroding ice. Some consequences for the research fields of non-glacial geomorphology, archaeology and botany include the possibility of subglacial museums and refugia. A time/space model describes geomorphological access to information from older events in glaciated areas.