Tennena Cone

Tennena Cone, alternatively Icebridge Cone, is a small volcanic cone in Cassiar Land District of northwestern British Columbia, Canada. It has an elevation of 2,390 metres (7,840 feet) and lies on the upper western flank of Ice Peak, the prominent south peak of Mount Edziza. The cone is almost completely surrounded by Mount Edziza's ice cap and is one of several volcanoes in the Snowshoe Lava Field on the Big Raven Plateau. Tennena Cone is 200 m (660 ft) high, 1,200 m (3,900 ft) long and up to 600 m (2,000 ft) wide; its symmetrical structure resembles a black pyramid. The cone and the surrounding area are in Mount Edziza Provincial Park, which also includes the Spectrum Range to the south.

Tennena Cone is part of the Mount Edziza volcanic complex, a group of overlapping volcanoes that have formed over the last 7.5 million years. It overlies four geological formations of this volcanic complex that formed during the Miocene, Pliocene and Pleistocene epochs, all of which consist of several types of volcanic rocks. Tennena Cone consists of pillow lavas, tuff breccias and lapilli tuffs of the younger Big Raven Formation, which were deposited by a small eruption under glacial ice. The exact timing of this eruption is unknown, but radiometric dating of alkali basaltic pillow lavas from Tennena Cone suggests that it occurred sometime in the last 33,000 years.