Climacograptus typicalis typicalis and associated shelly fossils from Lake Waswanipi, Québec

Abstract

Graptolites have been recovered from limestones at Lake Waswanipi, Quebec, in an Ordovician outlier on the Precambrian Shield. These limestones were previously interpreted as Wilderness, Trenton, or Richmond in age. They are now assigned a middle Climacograptus spiniferus to C . pygmaeus Zone age, dating the transgression over this part of the shield. Associated megafossils, though poorly preserved, are described. Correlations are made with other graptolite-bearing carbonates in eastern and central North America. Des Graptolites ont t t e recueillis de calcaires d'un placage ordovicien sur le bouclier precambrien au Lac Waswanipi. Ces calcaires etaient auparavant consideres comme etant d'PgeWilderness, Trenton, ou Richmond. Nous les attribuons a la moitie superieure de la Zone a Clirnacograptus spiniferus jusqu'a la Zone C . pygmaeus. Cet Pge date la transgression ordovicienne dans cette region du bouclier. Les mkgafossiles associes aux Graptolites, quoique ma1 conserves, sont egalement dtcrits. Des correlations sont proposees avec d'autres carbonates contenant des Graptolites dans I'est et le centre de I'Amerique du Nord.