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
Volcanic history of the Northern Cordilleran Volcanic Province the junction of the Pelly and Yukon rivers, Volcano Mountain in central Yukon consists of a cinder cone and a series of lava flows. It is the youngest volcano in the Fort Selkirk Volcanic Field and lava flows originated from fractures in the volcano's flank. These lava flows extend northeast and southwest of the volcano. The northeastern lava flow extends from Volcano Mountain whereas the southwestern lava flow extends from the volcano. These lava flows are composed of olivine nephelinite, a type of lava not commonly found on Earth. Nephelinite lavas are usually interpreted to have originated much deeper in