Middle Devonian (Eifelian) conodonts, and their stratigraphic implications, from the mid-Appalachians of Québec

Middle Devonian, Eifelian-age conodonts are described from Québec for the first time. The faunas are dominated by icriodontids, most of which are endemic to North America; only two species of Polygnathus, one of which is represented by two subspecies, are present. The faunas also probably represent the easternmost occurrences of the endemic icriodontid species and belong to the Eastern Faunal Realm of North America (of Sparling). In the near absence of polygnathids, reference to standard conodont zonation is made only indirectly. The Famine Formation, exposed at and near the townsite of Saint-Georges in the Eastern Townships, has yielded a fauna that is correlated with the costatus Zone. The Touladi Formation crops out near Lac Témiscouata, close to the border with the province of New Brunswick; its conodont fauna is correlated with the australis to kockelianus zones. A new species, Icriodus lesperancei, is described. Mid-Devonian thrusting in the Lac Témiscouata and Saint-Georges areas is presumably responsible for the shallow-water carbonates' being deposited in front of advancing Acadian thrust sheets. The Famine and Touladi formations were subjected to ensuing regional metamorphism during the Acadian Orogeny. This is reflected in the relatively poor preservation and the Color Alteration Index (CAI 4 and 5 of Epstein et al. and Rejebian et al.) of the enclosed conodonts.