Ring of Fire Ring of Fire The Ring of Fire is a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur. In a large horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and plate movements. It has 452 volcanoes (more than 75% of the world's active and dormant volcanoes). The Ring of Fire is sometimes called the circum-Pacific belt. About 90% of the world's earthquakes and 81% of the world's largest earthquakes occur along the Ring of Fire. All but three of the world's 25 largest
Circum-Superior Belt margin. The last collision occurred on the southeastern portion of the Superior craton to produce the Grenville orogeny 1,100 million years ago. Because most of the Circum-Superior Belt was formed by widespread mafic-ultramafic magmatism 1,884 to 1,864 million years ago along the Superior craton margin during these orogenies, a number of different suggestions have been made to explain the questionable origins of this large igneous province. It is also not clear if the Circum-Superior Belt has a single origin or it has several origins. Suggestions include back-arc rifting, foredeep flexure, mantle plumes and the breakup of a microcontinent. The geochemical