exhumed from a depth of ~100 km at the remarkable rate of ~20mm/yr. The rock at the centre of the tall domes in these islands was thus recently very deep in the Earth. Over a very short time, geologically speaking, these packets of rocks have ascended through the Earth's shallow mantle and pushed through the crust to form the gneiss domes we find today – the vestiges of the crust these massifs have thrust through are still draped as carapaces over the edges of the domes. These islands are thought to be geophysically significant because they lie immediately ahead of the west-most rift tip of the Woodlark spreading centre, which has been propagating westwards into the continent. The D'Entrecasteaux thus represent a stage of continental breakup just preceding fully-fledged volcanic spreading. History The group was named for the French navigator Antoine Raymond Joseph de Bruni d'Entrecasteaux, who, in his ship the Espérance'', passed through the area in 1792 while searching for his missing compatriot, Jean-François de Galaup, comte de La Pérouse. Almost a century later, in 1874, Captain John Moresby of made a running survey of the west coast of the islands and became the first European to make landfall. In 1891, the Methodist Church of Australia established a mission station on Dobu Island. There, natives were recruited to work in gold mines and on copra plantations. Another mission was established in 1898 at Bwaidoga, Mud Bay, on the south coast of Goodenough Island. The island group became a focus of activity in World War II when Imperial Japanese troops were marooned on Goodenough Island briefly in 1942, before being attacked by the Australian 2/12th Battalion. In 1943 RAAF mobile works squadrons constructed an airfield with a airstrip and other facilities at Vivigani Airfield on the site of a smaller, pre-war airstrip that existed at that location. It was used by allied forces from June 1943 to August 1944 as a staging point for operations in New Guinea and nearby occupied islands. Vivigani airstrip has been open to commercial service since 1963. A US Navy PT-Boat base was established on Fergusson Island in June 1942. References External links Archipelagoes of Papua New Guinea Islands of Milne Bay Province Volcanoes of Papua New Guinea