ABSTRACT: Lee slope deposition and the advance of the slipface? An investigation of morphological evolution of a dune at Pinery Provincial Park, Ontario.

CGRG Bibliography of Canadian Geomorphology
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Abstract

The amount of sand transported through a parabolic dune at Pinery Provincial Park varies seasonally with smaller amounts during summer and larger amounts during the winter months. Examination of the erosion pin data collected over 11 years reveals that the surface of the lake-side of the dune is generally accreting in the late summer and fall and then eroding during the winter months. Lee slope erosion pins revealed patterns of deposition with significant volumes of sand contributed to the lee face of the dune during the winter months as snow and sand are blown up the throat of the dune. Summer erosion results in the lakeward transport of sand up the lee slope as ripples migrate with the prevailing summer winds. The result is a change in the morphology of the lee face of the dune. The toe of the lee face is building slowly outward (landward) while the upper portions of the lee face increase in slope. This lee slope does not build into the forest as a precipitation dune with an avalanche slope. Instead, the lee slope builds landward and upward, dominated by tractional movement of sand punctuated by brief periods of avalanching.

Bibliography of Canadian Geomorphology