Tuzo Wilson Seamounts numerous smaller vents, with a total edifice volume of about 12 km. The lava emitted in eruptions at the Tuzo Wilson Seamounts is made of basalt, a common gray to black or dark brown extrusive volcanic rock low in silica content (the lava is mafic) that is usually fine-grained due to rapid cooling of lava. Glassy pillow lava is found at the seamounts, a type of rock typically formed when basaltic lava emerges from a submarine volcanic vent. The viscous lava gains a solid crust on contact with the water, and this crust cracks and oozes additional large blobs or
Ice-marginal lava flow activity and erosion. In the late 1800s, a debris flow from the Barrier created a large boulder field which gave Rubble Creek its name. Conditions are so bad that the area directly below the lava damn is considered uninhabitable and dangerous to human life. Hoodoo Mountain A second example of ice-marginal lava flows can again be found in British Columbia, this time near the border of Alaska. The Hoodoo Mountain Volcano is located in Northwestern British Columbia The volcano formed underneath a glacier, making it a subglacial formation. The Hoodoo Mountain Volcano is a flat-topped stratovolcano as a result of