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
Japanese settlement in the Marshall Islands Marshallese language. At least one Shinto shrine or Buddhist temple was found in each settlement with a sizeable Japanese populace. In Jaluit, Wotje, Kwajalein, Enewetak and Maloelap, several Shinto shrines were built during the 1930s. When the Americans invaded the Marshall Islands in 1944, all the existing Shinto shrines were either destroyed in air raids, or were demolished. People of mixed Japanese–Marshallese heritage subsequently adopted Christianity in favour of Buddhism or Shinto after the Japanese surrender. As compared to other Micronesian islands, most Marshallese adopted Japanese customs within the first few years of the Japanese administration. An Australian journalist travelling