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 New lava flows will cover the surrounding land, isolating the kīpuka so that it appears as a (usually) forested island in a barren lava flow. Lava domes are formed by the extrusion of viscous felsic magma. They can form prominent rounded protuberances, such as at Valles Caldera. As a volcano extrudes silicic lava, it can form an "inflation dome", gradually building up a large, pillow-like structure which cracks, fissures, and may release cooled chunks of rock and rubble. The top and side margins of an inflating lava dome tend to be covered in fragments of rock, breccia and ash. Examples