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
Banks Islands Banks Islands The Banks Islands (in Bislama "Bankis") are a group of islands in northern Vanuatu. Together with the Torres Islands to the northwest, they make up the northernmost province of Torba. The group lies about north of Maewo, and includes Gaua and Vanua Lava, two of the 13 largest islands in Vanuatu. In 2009, the islands supported a population of 8,533 on a land area of 780 km². The largest island is Gaua (formerly called Santa Maria), which has a rugged terrain, rising to Mount Gharat, an active volcano at the centre of the island, at . The freshwater