Bonin Islands Pacific Plate is subducting under the Philippine Sea Plate, which creates an oceanic trench to the east of the islands: the Bonin Trench. The crust of the Ogasawara Islands was formed by volcanic activity when subduction began 45–50 million years ago, and is composed mostly of an andesitic volcanic rock called boninite, which is rich in magnesium oxide, chromium, and silicon dioxide. The Ogasawara Islands may represent the exposed parts of an ophiolite that has not yet been emplaced on oceanic crust. The rocks of the Volcano Islands are much younger; Iwo Jima is a dormant volcano characterized by rapid
Cerro Azul (Ecuador volcano) Cerro Azul (Ecuador volcano) Cerro Azul (Spanish: "Blue Hill") is a shield volcano on the south western part of Isabela Island in the Galápagos Islands. At a height of it is the second highest peak in the Galapagos and due to its topographic prominence of over it is categorised as an ultra. The volcano is one of the most active in the Galapagos, with the last eruption between May and June 2008. The Galapagos Islands are believed to be formed from a mantle plume which creates a hotspot of volcanic activity away from plate boundaries where islands then form above