Two high-carbonate sediment cores from the mid-Atlantic and one from the Caribbean were analyzed for major constituents by wet-chemical methods. All major constituents appeared to have been deposited at a greater rate during glacial times than during the post-glacial period. The elements involved in clay sedimentation showed a sharp increase in deposition rate at the end of the last glaciation. In the Atlantic cores, manganese showed evidence of post-depositional rearrangement. In the Caribbean core, both manganese and magnesium are inversely correlated with paleotemperature and presumably were deposited to a large extent by the same mechanism.