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 remain undated, indicating the existence of magmatic rocks with the same age as those of the Circum-Superior Belt is probable. It contains two large copper-nickel mining districts; the nickel-bearing Thompson Belt at the northwestern portion of the Superior craton and the Cape Smith Belt at the northern portion of the Circum-Superior Belt. The Circum-Superior Belt was formed 1,884 to 1,864 million years ago when the Superior craton was surrounded by mountain building processes, including the Trans-Hudson, New Quebec and Penokean orogenies. The major Trans-Hudson orogeny had its appearance when the Superior craton collided with the Rae-Hearne craton 1,900 to 1,800