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
Volcano Block Building Volcano Block Building The Volcano Block Building is a historic structure in Hilo, Hawaii built in 1914. Completed in 1914, this two story commercial building of reinforced concrete in the Italian Renaissance style is representative of the major structures built in Hilo between 1910 and 1915 as the city grew to be the second largest commercial center in the Hawaiian Islands. Measuring approximately 60 feet by 90 feet and fronting on Waianuenue Avenue, the structure occupies the site of the former Volcano Stables. Three retail spaces on the ground floor each have separate store fronts. The entry stair to the