Notes on the Shoreline Recession Along the Coast of the Yukon Territory

Abstract

The 150-km.-long stretch of the coast between Herschel Island and the Mackenzie Delta terminates in bluffs cut into Pleistocene silts, sands, and gravels. No bedrock has yet been observed; if present, its occurrence must be very local. The coastal bluffs which are up to 50 m. high, are constantly being undermined by waves and by the melting of numerous thick tabular ground-ice sheets lying close to sea-level. As the ice sheets are found only in fine-grained sediments, coastal retreat is especially rapid long silty to clayey bluffs. Similarly rapid recession has taken place along the northern coast of Alaska and from the Mackenzie Delta east to Langton Bay. It is the purpose of this note to describe some of the geomorphological and historical evidence fo recession of the coast of the Yukon Territory. The field observations were made while the writer was carrying out studies for the Geographical Branch, Department of Mines and Technical Surveys, Ottawa.