FOREDUNE DEVELOPMENT ON ILES-DE-LA-MADELEINE (QUEBEC), ATLANTIS CANADA

The foredune, in this cool-temperate, sediment-abundant, relatively hi gh wind and wave energy environment, is generally a single ridge with a mean height of 5.1 m (max. 11.4 m) and width of 25-35 m. Pioneer veg etation is dominated by Ammophila breviligulata. Four foredune types w ere identified: scarped, scarped with blowouts, scarped with incipient foredune, and nonscarped, the first being the most common, occupying more than 50% of the shoreline. Foredune erosion and retreat is occurr ing at an average rate of 0-8 m.a(-1). The marked differences in dune character between the west and east coasts of the islands are related to differences in wave energy and shoreline dissipativeness. The highe r energy west coast exhibits more dynamic dunes with more frequent blo wouts, which may develop into parabolic forms.