Ice-Cored Rock Glacier, Galena Creek, Northern Absaroka Mountains, Wyoming

Geophysical analysis of transverse ridges and internal structure at Lone Peak Rock Glacier, Big Sky, Montana, USA

“…The application of GPR to rock glacier and other frozen ground surveying is effective and well described by Degenhardt and Giardino (2003) and Woodward and Burke (2007). These GPR data suggest that the internal ice body of a rock glacier is typically buried beneath meters to decimeters of rock debris (Elconin and LaChapelle, 1997), and is composed of interstitial ice between debris (Haeberli and others, 2006) or as pure ice (Potter, 1972). The origin of ice may be sedimentary (seasonal snow accumulation, avalanching, rockfall), periglacial (refreezing of meltwater seeping into pre-existing sediments) (Guglielmin and others, 2004) or glacial (buried glacier ice) (Whalley and Azizi, 2003).…”

“…No definitive explanation of transverse ridge formation exists, though there are multiple working hypotheses as to their genesis (e.g. Wahrhaftig and Cox, 1959;Potter, 1972;Haeberli, 1985;Olyphant, 1987;White, 1987;Loewenherz and others, 1989;Barsch, 1996;Kääb and others, 1998;Fukui and others, 2008;Degenhardt, 2009;Shean and Marchant, 2010). Transverse ridges have been described as the result of exogenous processes (e.g.…”

Ice exposures in rock glaciers

“…2) may be the result of the late spring and late penetration of summer warming. We have not observed such frozen debris before at Nautardalur but it is a good example of the "superimposed" ice which can accumulate over a glacier ice core (Potter, 1972;Whalley, 1983). At Nautardalur the superimposed ice probably melts during most summers.…”

“…This has important consequences for our interpretation of these features, in terms of both the formative mechanisms and the environmental implications of their existence. Glacierice exposures have been described by authors such as Outcalt and Benedict (1965) and White (1975) at the Arapaho rock glacier in the Colorado Front Range, Potter (1972) in Wyoming and Calkin and others (1987) in Alaska as well as by Johnson and Lacasse (1988); Whalley and Martin (1992) give further examples. However, there have been no actual observations of glacier ice in more than one or perhaps two locations on anyone rock glacier.…”

Ice Segregation as an Origin for Lenses of Non-Glacial Ice in “Ice-Cemented” Rock Glaciers

“…The existence of glacial ice is easy to understand and explain, because in many areas, including the Rocky Mountains of Canada and the United States, and the central Andes of Argentina and Chile, glacial ice can be seen above debriscovered glacial ice, which changes down-slope into collapsing stagnant glacial ice (thermokarst) and/or ice-cored debris that displays the structural flow characteristics of a rock glacier (Corte, 1976[b]). Foster and Holmes (1965), Potter (1972), Luckman and Crockett (1978), Whalley (1976), White (1976), and many others have described active rock glaciers in which the frozen core is massive ice of glacial origin.…”