Genetically Complex and Morphologically Diverse Pingos in the Fish Lake Area of South West Banks Island, N. W. T., Canada

An unusually wide variety of pingo landforms located within a relatively restricted 50 km2area of thick surficial sediments and permafrost is documented. Pingo growth and decay may occur independent of climatic change as witnessed by examples of embryonic, active and collapsed/collapsing features. The presence of deep kettle lakes in the area probably creates a dynamic system of interlinked taliks which influence the groundwater supply to centres of ground ice growth. The field relationships suggest that the pingo growth mechanisms may embrace both hydrostatic and hydraulic processes. All the pingos post-date the Last Glacial Maximum ice retreat and the youngest was actively growing in AD 1981.