Pyramid Mountain

Pyramid Mountain, on the Murtle Plateau in Wells Gray Provincial Park in east-central British Columbia, formed about 12,000 years ago when a volcanic eruption occurred beneath thick glacial ice. Now understood as a subglacial mound rather than a cinder cone, it was built under roughly 1,600 metres of ice as lava rapidly cooled against surrounding meltwater and ice. This process created a hard surface containing smoothed, non-volcanic stones carried by the glacier. Its unusual formation explains why it has no crater or lava flows at its base, and why a smaller cone-like feature on its east side is interpreted as a slump after the ice melted away.

British Columbia · Canada