The Great Bear magmatic zone (GBMZ) is a Paleoproterozoic (1.875–1.86 Ga) multi-collisional orogenic belt of which 100 km × 400 km (62 mi × 249 mi) is exposed in the northwestern Canadian Shield east of Great Bear Lake, Northwest Territories.

[1] Covering 40,000 km2 (15,000 sq mi), the GBMZ forms part of the Wopmay orogen together with the Coronation Margin and Hottah terrane and overlies these two tectonic elements.

[1] The GBMZ formed following a flip in subduction polarity from east to west dipping when the Hottah terrane collided with the Slave Craton 1.875–1.855 Ga.[2] The GBMZ is a magmatic arc on the western margin of the Wopmay orogen which developed 1.875–1.840 Ga on older Proterozoic basement rocks.

Topographically the GBMZ is characterised by granitic low relief areas with former volcanoes forming 150 m (490 ft)-high hills.

[3] Several plate tectonic reconstructions propose an Archean-Paleoproterozoic connection between the cratonic core of North America, the continent Laurentia, and that of Siberia, the continent Siberia, based on geological connections and paleomagnetic evidence.