a preliminary basis for subdivision of the Quaternary in deep-sea sediments. The magnetic-reversal, oxygen-isotope, and calcite-dissolution/coarse-fraction scales have been correlated by determination on the same core materials, and absolute dates applied by K
/Ar or C dating of materials in known positions on one or another of these scales. FADs and LADs have been determined in cores for which either a magnetic-reversal, oxygen-isotope, or calcite-dissolution/coarse-fraction scale has also been available