Snowshoe Lava Field

The Snowshoe Lava Field (SLF) is a largely buried volcanic field at Mount Edziza in British Columbia, Canada. It reaches an elevation of 2,390 metres (7,840 feet) and engulfs more than 40 square kilometres (15 square miles) of the Big Raven Plateau and adjacent valleys with blocky lava flows. The Snowshoe Lava Field is the southernmost of two lava fields on the Big Raven Plateau, the other being the smaller Desolation Lava Field at the northern end of the plateau. It is in Mount Edziza Provincial Park and is part of the Mount Edziza volcanic complex, the latter of which consists of several other volcanic landforms such as shield volcanoes, stratovolcanoes, lava domes and cinder cones. Sezill Creek, Shaman Creek, Taweh Creek and several other unnamed streams in the Stikine River watershed drain the Snowshoe Lava Field. Access to the lava field is only by aircraft or by a network of horse trails from surrounding roads.

The Snowshoe Lava Field issued from several eruptive centres during the Holocene, most of which are clustered on the southern and western flanks of Ice Peak at elevations more than 1,800 m (5,900 ft). Volcanism in the lava field began with the eruption of three subglacial volcanoes when outlet glaciers of Mount Edziza's ice cap extended to lower elevations during the climax of a glacial advance. This was followed by the creation of four volcanoes whose eruptions were at first subaqueous and then transitioned subaerially. The youngest volcanoes in the Snowshoe Lava Field are completely subaerial in origin and issued most of the blocky lava flows comprising much of the current surface of the lava field. Alkali basalt and hawaiite of the Big Raven Formation are the main volcanic rocks comprising the Snowshoe Lava Field, but most of them are obscured by trachyte pumice of the Sheep Track Member.