Athabasca Glacier, Canada - a field example of subglacial ice and till erosion?

摘要

The Athabasca Glacier, resting on a rigid bed, provides an excellent example of subglacial ice and till erosion. The presence of a thin mobile till laver is shown by the presence of flutes, saturated till layer, push moraines and ploughed boulders. Cross-cutting striations. v-shaped striations and reversed stoss-and-lee clasts are indicative of clasts rotating within this layer. As the till moves it erodes the bedrock and clasts within it. A combination of erosion by ice and till produces stoss-and-lee-clasts and generates striations on flutes and embedded clasts, as well as eroding the bedrock into a continuum of smoothed, rounded and streamlined forms. Copyright (c) 2005 John Wiley & Sons, Ltd.