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
Music of the Austral Islands houses and "tapa". Music of the Austral Islands The Austral Islands are part of the territory of French Polynesia. The music of the islands is similar to the music of other Polynesian islands. The largest of the Austral Islands is Tubuai, which is known for its ancient, atonal singing style, said to be the purest representation of pre-contact Polynesian music in French Polynesia. The Encyclopædia Britannica has reported a carving, found on Raivavae, which depicts dancers alternating with rows of crescents, sometimes said to represent the distinctive skirts of the dancers. This carving style is used on traditional drums, as