Bedrock mapping in the Committee Bay Belt, Laughland Lake area, central mainland, Nunavut

Abstract

The Committee Bay Belt is underlain by northeast-trending rocks of the Archean Prince Albert Group, flanked to the north and west by paragneiss and associated peraluminous and metaluminous granitoid bodies, and to the south and east by metaluminous granitoid bodies. The Prince Albert Group comprises dominant semipelite and psammite, iron-formation and quartzite, with less abundant, spinifex-textured komatiite, and rare basaltic and intermediate to felsic volcanic rocks. Synvolcanic intrusions ranging from rare gabbro, quartz diorite and diorite, to abundant tonalite, granodiorite and granite, outcrop south, east, and northwest of a plutonic body of tonalite to granodiorite interpreted to be younger than the supracrustal belts. To the west and north, metamorphic grade increases to amphibolite facies with consequent development of paragneiss and accompanying peraluminous melts. To the southeast, a granitic intrusive suite is cut by an anorthosite complex, both of which are intruded by Paleoproterozoic monzogranite.