ABSTRACT: Detailed glacial geomorphology of a proglacial bedrock area at Castleguard Glacier, Alberta

CGRG Bibliography of Canadian Geomorphology
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Abstract

Detailed observations and mapping of a 104 m2 limestone surface recently exposed by the retreat of Castleguard Glacier reveal considerable information about the spatial distribution of former active subglacial processes. Regions dominated by the spatial distribution of formerly intimate ice-rock contact are either abraded or covered with subglacial carbonate precipitate and associated with solutional features. The subglacial hydraulic systems is represented by a practically continuous non-arborescent network of former subglacial cavities and channels. The aerial extent and estimated capacity of this network implies that the glacier was generally not in contact with about 30% of its bed and that considerable amounts of water could be stored in this system. Estimates of former water flow velocities in subglacial bedrock channels based on dissolutional scallops are roughly half those expected for equivalent, but sub-aerial channels, implying an impedance of subglacial water flow by the glacier. With the exception of distinct narrow zones, which parallel the ice flow, a generally low debris content of basal ice may be inferred from estimates of the retreat rate and of the concentration of debris left on proglacial surfaces.

Bibliography of Canadian Geomorphology