A methodology to reconstruct small and short-lived ice-dammed lakes in the Appalachians of Southern Québec

• Published in: Quaternary international 2003, Vol.99, p.59-71
• Main Authors: LaRocque, Armand, Dubois, Jean-Marie M, Leblon, Brigitte
• Format: Article
• Language: English
• ISSN: 1040-6182; 1873-4553
• DOI: 10.1016/S1040-6182(02)00112-X

Previous studies on the deglaciation of the Appalachians of southern Québec reconstructed only the most extensive ice-dammed lakes and the most stable glaciolacustrine water levels. They only used the best developed shoreline features, and thus were not able to reconstruct small or short-lived ice-dammed lakes, both being characterized by a weak development of their features. We propose a methodology to reconstruct glacial lakes which follows three main steps: (1) the mapping of shoreline features, generally the best developed ones, as in previous studies; (2) the delineation of the former shoreline for each water level, by also considering the less well-developed shoreline features which were found during field surveys designed as a function of the presumed shoreline position; and (3) the mapping of the maximum extension of the water plane, which includes the location of the former ice dam and of the former glacial lake spillway. In southern Québec, small ice-dammed lakes were numerous and important because they shaped the geomorphology of the region during the deglaciation. They are thus among the key components of a deglaciation model for this area.