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 occupation of the Andaman Islands Close Cover<br> Invasion Force<br> Minesweeper Division 1<br> Special Minesweeper Division 91<br> Air Unit<br> Port Blair was occupied on the 23 March 1942. The garrison offered no resistance to the landings, and were disarmed and interned; many of the Sikh militia later enlisted in the Indian National Army. The British militia officers were sent to Singapore as POWs, whilst Chief Commissioner Waterfall, Deputy Commissioner Major A.G. Bird and the other British administrative officers were imprisoned. The Japanese released the prisoners held in the jail, one of whom, Pushkar Bakshi, became their principal collaborator. The islands were put under the authority of