Devon Island's Oriented Landforms as an Analog to Illinois-Type Paha
Abstract:Illinois-type paha are unusual regional landforms located in northwestern Illinois, USA, consisting of inactive, oriented, oblong ridges composed of either loess or bedrock capped by loess. A recent study reidentified the paha of Illinois as relict oriented, snowmelt interfluves, formed by erosion from snowdrifts or snow dunes occupying oriented valleys alternating with inter-valley ridges during the cold phase(s) of the Pleistocene Epoch. Devon Island, located in the high Arctic, exhibits similar regional, oriented inter-valley ridges and adjacent oriented valleys with the added feature of overlying, oriented snowbanks or snow dunes. The similarities between both regional landforms include morphology, dimensions, parallelism, orientation to the (paleo)wind; and the fact that the oriented dissection was formed irrespective of the steepest direction of the general slope. Oriented nival landforms with the same peculiar characteristics also exist on Resolute, Cornwallis Island, adjacent to Devon Island. Nivation compounded by indirect influence of the wind is proposed as the causal agent for all of the previously mentioned landforms.
Document Type: Research Article
Publication date: 2003-10-01