Southeastward ice flow in central Quebec and its paleogeographic significance

Abstract

Directional glacial erosional marks located systematically on the southwest side of rock outcrops in the Chibougamau and Lac Mistassini areas in west-central Quebec indicate unequivocally a sustained regional event of southeast ice flow prior to the last or regional southwest flow from New Quebec. Striations from the former ice flow are consistently oriented at around 120° azimuth and are observed, albeit at scattered occurrences, within an area covering thousands of square kilometres. Although the age of the southeast ice flow event cannot be determined, it is considered more likely to be of Wisconsinan age on the basis of the well preserved state of its features and the lack of deep weathering on surfaces where these are observed. It is suggested that the early ice flow event might have been fed by a local outflow centre on the east side of James Bay, perhaps extending as a ridge east of Hudson Bay.