[2] The lowermost lavas were produced by melting in the garnet stability field below the surface at a depth of more than 90 km (56 mi) in a mantle plume environment beneath the North American lithosphere.

[2] During the Early Jurassic period 196 million years ago, the New England or Great Meteor hotspot existed in the Rankin Inlet area of southern Nunavut along the northwestern coast of Hudson Bay, producing kimberlite magmas.

[4] Widespread basalt volcanism occurred between 60.9 and 61.3 million years ago in the northern Labrador Sea, Davis Strait and in southern Baffin Bay on the eastern coast of Nunavut during the Paleocene period when North America and Greenland were being separated by tectonic movements.

The cause of this volcanism might be related to partial melting from movement of a transform fault system extending from Labrador Sea to the south and Baffin Bay to the north.

The Fort Selkirk Volcanic Field in central Yukon consists of valley-filling basalt lava flows and cinder cones.

[6] Ne Ch'e Ddhawa, a cinder cone 2 km (1 mi) to the connection of the Yukon and Pelly rivers formed between 0.8 and one million years ago when this area lay beneath the vast Cordilleran Ice Sheet.

[9] This volcanic belt lies largely in the U.S. state of Alaska, but extends across the Alaska-Yukon border into southwestern Yukon where it contains scattered remnants of subaerial lavas and pyroclastic rocks which are preserved along the entire eastern fringe of the ice covered Saint Elias Mountains.

[9] Considerable recent uplift, accompanied by rapid erosion, has reduced once vast areas of upper Tertiary volcanic rocks to small isolated remnants.

[10] Unproven legends from indigenous people in the area indicate the final eruption from Mount Churchill 1,250 years ago disrupted food supplies and forced them to move further south.