Arctic Ocean History Is Deciphered By Ocean-drilling Research

Sediment cores retrieved from the Arctic's deep-sea floor by the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) have provided long-absent data to scientists who report new findings in the June 21 issue of Nature. A team of ACEX researchers report that the Arctic Ocean changed from a landlocked body of water (a 'lake stage') through a poorly oxygenated 'estuarine sea' phase to a fully oxygenated ocean at 17.5 million years ago during the latter part of the early Miocene era...