Gilbert and Ellice Islands their own administration. As a consequence of the Ellice Islands self-determination referendum, 1974, separation occurred in two stages. The Tuvaluan Order 1975 made by the Privy Council, which took effect on 1 October 1975, recognised Tuvalu as a separate British dependency with its own government. The second stage occurred on 1 January 1976 when two separate administrations were created out of the civil service of the Gilbert and Ellice Islands Colony. The British conducted a formal inquiry into Tuvaluan attitudes towards secession, and announced that a referendum was to be held, in which Tuvaluans could choose to remain with the
Geology of the Pacific Ocean . The Pacific Ocean developed from the Panthalassa, a vast global ocean, following the breakup of the supercontinent Pangaea in the Mesozoic Era, gradually forming Gondwana and Laurasia, which in turn divided. There is no firm date for when the changeover occurred, as the replacement of the sea bed is a continuous process, though reconstruction maps often change the name from Panthalassic to Pacific around the time the Atlantic Ocean began to open. The Panthalassic Ocean first opened around 750 million years ago at the breakup of Rodinia, but the oldest Pacific Ocean floor is only around 180 Ma old.