Ring of Fire volcanic eruptions of the last 11,700 years occurred at volcanoes in the Ring of Fire. The Ring of Fire is a direct result of plate tectonics: the movement and collisions of lithospheric plates, especially subduction in the northern portion. The southern portion is more complex, with a number of smaller tectonic plates in collision with the Pacific plate from the Mariana Islands, the Philippines, Bougainville, Tonga, and New Zealand. The presence of a belt of volcanic activity surrounding the Pacific Ocean was observed in the 19th century. "They [the Japanese Islands] are in the line of that immense circle of
Circum-Superior Belt features are present in the Circum-Superior Belt, including dikes, sills and volcanics that comprise geologic formations. This geologic belt is considered to be a large igneous province because its magmatic rocks were emplaced over an extremely short geological time span. Even though the Circum-Superior Belt was emplaced during an extremely short geological time span, the associated magmas were probably derived from a number of separate sources. Most of the Circum-Superior Belt lies along the margin of the Superior Craton, which is the most extensive fragment of Archean crust on Earth. However, a number of igneous rocks within the Superior craton