page_title: Mount Edziza volcanic complex
section_title: Central volcano flank eruptive period
hierarchical_section_title: Mount Edziza volcanic complex / Geology / Eruptive history / Central volcano flank eruptive period
caption_attribution_description: English: Geologic map of lava flow and the Eve and Sidas Cones of the Mount Edziza volcanic complex in northern British Columbia, Canada.
context_page_description: The Mount Edziza volcanic complex is a large and potentially active north-south trending complex volcano in Stikine Country, northwestern British Columbia, Canada, located 38 kilometres southeast of the small community of Telegraph Creek. It occupies the southeastern portion of the Tahltan Highland, an upland area of plateau and lower mountain ranges, lying east of the Boundary Ranges and south of the Inklin River, which is the east fork of the Taku River. As a volcanic complex, it consists of many types of volcanoes, including shield volcanoes, calderas, lava domes, stratovolcanoes, and cinder cones.
  Most of the Mount Edziza volcanic complex is encompassed within a large provincial park called Mount Edziza Provincial Park. Named after Mount Edziza, this 2,660.95 km² park was established in 1972 to preserve the volcanic and cultural treasures unique to the northern British Columbia area. The Mount Edziza volcanic complex is remote, and, without roads, accessible only along trails. The easiest access is from Highway 37 and a spur road from Dease Lake to Telegraph Creek.
context_section_description: The fifth and final phase of eruptive activity occurred from secondary volcanic vents along the flanks of the four central volcanoes starting 10,000 years ago. This phase of activity began at a time when remnants of glacial ice were still present and continued after the glacial period. The initial flank eruptions, quenched by glacial meltwater, formed hyaloclastite tuff rings, whereas later activity created 30 small cinder cones, primarily of basaltic composition, including Mess Lake Cone, Kana Cone, Cinder Cliff, Icefall Cone, Ridge Cone, Williams Cone, Walkout Creek Cone, Moraine Cone, Sidas Cone, Sleet Cone, Storm Cone, Triplex Cone, Twin Cone, Cache Hill, Camp Hill, Cocoa Crater, Coffee Crater, Nahta Cone, Tennena Cone, The Saucer and the well-preserved Eve Cone. These cinder cones were formed no earlier than the year 700 based on the age of burnt plant stems still rooted in former soil under 2 metres (6.6 ft) of loose basaltic fragments. These cinder cones were built on the basaltic fragments and blocky lava fields surrounding the cones. The Snowshoe lava field, on the southern end of the Big Raven Plateau, is one of the areas of young lava flows in the region while the Desolation lava field, on the northern end of the Big Raven Plateau, is the largest area of young lava flows, covering an area of 150 km². The longest lava flow is 12 kilometres (7 mi). This volcanic activity was followed by at least two younger, but still undated eruptions, including an undated air-fall pumice deposit.
  The undated air-fall pumice deposit exists across the southwestern part of the Big Raven Plateau called Sheep Track Pumice or Sheep Track member. Pumice is a light volcanic rock full of air spaces and commonly pale in colour, ranging from white, cream, blue or grey, but can be green or black. The Sheep Track Pumice is mysterious because the vent of its origin is unknown, even though it is estimated from its state of preservation to be younger than 500 years. This pumice deposit emphasizes one of the significant volcanic hazards linked to the Mount Edziza volcanic complex – the likelihood of a violent explosive eruption. The volcano that produced the pumice might be covered by glacial ice. Collaborators at the University of British Columbia have started work on samples collected from deposits of Sheep Track Pumice.
caption: A large Edziza lava flow and the Eve and Sidas cones
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