Author: Thomas E. Bolton

Publisher:

Published: 1972

Total Pages: 58

ISBN-13:

The six formations detailed on the preliminary geological map of Anticosti Island, Quebec, represent an uninterrupted sequence of nearly flat-lying rocks of Upper Ordovician to Middle Silurian ages. The Upper Ordovician strata, divisible into two formations, Vaureal and Ellis Bay, are persistent, alternating calcareous and argillaceous units, each bearing distinct marine faunal assemblages. These rocks occupy the northwestern one-third of the island. The succeeding Lower and Middle Silurian strata of the Becscie, Gun River and Jupiter Formations are more variable lithological units, the uppermost Chicotte Formation, occurring only along the southern coast of the island, being everywhere a massive, cronoidal limestone. These Silurian formations, of Llandoverian and early Wenlockian ages (Alexandrian and early Niagaran), are highly fossiliferous and divisible into several tentative faunal units. Characteristic fossils from each of the six formations are illustrated in a preliminary fashion and grouped by formation.