Colloque

Graptolite faunas from the middle and upper ordovician of the St. Lawrence lowland, area of lake St. John and the Island of Anticosti, Province of Quebec

John Riva

Membre a labase

John Riva

Résumé du colloque

Graptolites of the Trenton and the Utica can be assigned to three, if not four, successive assemblages. These assemblages, which range through hundreds of feet of section in southern Quebec where the Trenton and Utica shales attain thickness close to 3,000 feet, but extend vertically through only a few tens of feet in condensed sections of the island of Anticosti. Graptolite faunas of Southern Quebec continue unchanged across the Lowland to the Island of Anticosti with only a few significant changes. Trenton graptolites on Anticosti contain a few 'British' forms which gradually disappear southwestward across the Lowlands.