A glaciofluvial origin for drumlins of the Livingstone Lake area, Saskatchewan

Abstract

The Livingstone Lake drumlin field of northern Saskatchewan is on the Athabasca Plains. It is draped over high ground underlain by the Precambrian Athabasca Sandstone. The drumlins occur in spindle, parabolic, and transverse asymmetrical forms. A map of individual drumlins shows that features of similar form occur together. The drumlins are related on a regional scale to even larger landforms. There is also an arrangement of drumlins in streams parallel to the assumed flow direction. These patterns illustrate spatial organisation of the drumlin-forming flows. The Livingstone Lake drumlins are closely related to tunnel valleys, large crescentic scours, and eskers. Exposed bedrock reveals widespread scalloping and sichelwannen. An argument is made that drumlins are related to these glaciofluvial forms but were created at different times and by different flows than those forming small-scale flutings and other lodgment features. Sediments within the drumlins are mainly primary water-sorted deposits some of which were resedimented by mass movements. There are also large, striated boulders. Deposition in subglacial cavities is suggested. This explanation is supported by a comparison of patterns and forms of erosional marks produced by wind and water and the implied form of the subglacial cavities. The Livingstone Lake drumlins are considered to represent infillings of cavities developed by meltwater erosion of the underside of glaciers. This conclusion stresses the geomorphic and sedimentologic importance of subglacial meltwater. It has important implications for the behaviour of the large Pleistocene ice sheets and the interpretation of glacigenic sediments. Consequently, it has direct bearing on glacial stratigraphy and chronology.

Fresh arguments against the Shaw megaflood hypothesis. A reply to comments by David Sharpe on “Paleohydraulics of the last outburst flood from glacial Lake Agassiz and the 8200 BP cold event”

“…However, we strongly disagree that so much water could have been released from a huge reservoir beneath the Laurentide Ice Sheet (LIS). For those unfamiliar with the literature on the subject, Lake Livingstone is the inferred subglacial or supraglacial reservoir that held the inferred water that was released by an inferred subglacial flood over a drumlin field in the region of contemporary Livingstone Lake in northern Saskatchewan (Shaw and Kvill, 1984;Shaw et al, 1989). Unlike glacial lakes Agassiz and Ojibway, which are known to have existed and have reasonably well constrained reservoir geometries, the existence and location of glacial Lake Livingstone are unclear.…”

The instability theory of drumlin formation applied to Newtonian viscous ice of finite depth

“…Shaw & Kvill 1984;Shaw & Sharpe 1987;Shaw 1994), which envisages subglacial flood water eroding sediment and thus carving drumlins. This mechanism has been widely criticized (e.g.…”

Significance of Sedimentological Studies on the Wisconsinan Stratigraphy of Southern Ontario

“…However, many of these landform-sediment relationships, long accepted to be true, need further investigation (SHAW, 1983b;LAWSON, 1984;McCABE et al, 1984;SHAW and KVILL, 1984). Two examples of landform-sediment studies from the writers own works will be presented, one from the Scarborough Bluffs, and the second from the Lake Erie Bluffs.…”