ABSTRACTAlluvial fans have developed under semiarid conditions in the continuous permafrost zone along the Aklavik Range of northwestern Canada. The fans are formed by a series of steep, narrow, coalescing aprons debouching from nivation-modified hollows in shale and siltstone.The morphology and development of one of these fans, the Mount Goodenough North fan, has been studied in detail. Channel development is largely confined to the fan head area, and the lower parts of the fan are marked by gelifluction terracettes and earth hummocks. The non-channelized parts of the fan are dominantly composed of silty diamicton units.The alluvial fan was formed by gelifluction and snowmelt-induced debris flow, with fluvial processes playing a minor role. These processes are a consequence of the semi-arid conditions marked by summer water influx, generated through snowmelt and degradation of segregated ice developed preferentially in the silty diamictons. The dominant controls on the mode of fan development and sedimentation are the composition and texture of the source material, and the presence of snowfall accumulations and segregated ice. The aridity of the climate limits the amount of fluvial activity, but in itself does not represent the controlling factor in fan morphology and sedimentation.