Volcanology of Northern Canada that remain unvegetated and appear to be only a few hundred years old. However, dating of sediments in a lake impounded by the lava flows indicated that the youngest lava flows could not be younger than mid-Holocene and could be early Holocene or older. Therefore, the most recent activity in the Fort Selkirk volcanic field is unknown. The lava flows from Volcano Mountain are unusual because they originate much deeper in the Earth's mantle than the more common basaltic lava flows found throughout the Yukon and are very uncommon in the geological record. This lava, known as olivine nephelinite, is
Lava deeply, forming dangerous chasms, and a fall against 'a'a lava is similar to falling against broken glass. Rugged hiking boots, long pants, and gloves are recommended when crossing lava flows. Diverting a lava flow is extremely difficult, but it can be accomplished in some circumstances, as was once partially achieved in Vestmannaeyjar, Iceland. Tephra is volcanic ash, lapilli, volcanic bombs or volcanic blocks. Lava Lava is molten rock generated by geothermal energy and expelled through fractures in planetary crust or in an eruption, usually at temperatures from . The structures resulting from subsequent solidification and cooling are also sometimes described