• Member description taken from 2007 Long. Tempestite frequency curves: a key to Late Ordovician and Early Silurian subsidence, sea-level change, and orbital forcing in the Anticosti foreland basin, Quebec, Canada. Can. J. Earth Sci. Vol. 44, 413-431. "The Grindstone Member, at its type section on the north-east coast of Anticosti Island, consists of >14 m of lami-nated to thin-bedded, very fine sandstones (subfeldspathic to feldspathic bioarenites) and minor laminated calcareous mudstones. These mixed siliciclastic–carbonate sandstones appear to be restricted to the east end of the island; within 15 km of the type section they pass into sandy limestones. To the west, at Vauréal Falls, they are dominated by highly bioturbated thin-bedded micrites, interbedded with thin to thick beds of calcarenite of coarse sand to granule grade. At the west end of the island the member consists of 21 m of predominantly laminated to thin-bedded planar to wavy laminate (irregular, subnodular) micrites, with abundant bioturbation. Grainstones are rare and are typically discontinuous lenticular."