oxygen-isotope stage One of the glacial or interglacial stages revealed by oxygen-isotope curves. Curves from Atlantic and Pacific deep-sea cores were divided by C. Emiliani into 16 stages, their fluctuations being correlated with ice-sheet growth and decay. N. J. Shackleton and N. D. Opdyke extended these subdivisions in 1973, from their studies of a core from the western Pacific in which 23 stages were recognized. These are presumed to represent a continuous record from about 870 000 years BP. In 1976, J. Van Donk obtained curves from a core in the equatorial Atlantic which yielded 42 isotope stages, representing 21 glacial and 21 interglacial stages.

oxygen-isotope stage One of the glacial or interglacial stages revealed by oxygen-isotope analysis. Graphical plots from Atlantic and Pacific deep-sea cores were divided by C. Emiliani into 16 stages, their fluctuations being correlated with ice-sheet growth and decay. N. J. Shackleton and N. D. Opdyke extended these subdivisions in 1973, from their studies of a core from the western Pacific in which 23 stages were recognized. These are presumed to represent a continuous record from about 870 000 years bp. In 1976 J. Van Donk obtained curves from a core in the equatorial Atlantic which yielded 42 isotope stages, representing 21 glacial and 21 interglacial stages.