Figure F38. A. Shipboard biostratigraphic and magnetostratigraphic datums and age-depth model. Solid horizontal lines = lithologic unit boundaries, dashed horizontal lines = lithologic subunit boundaries. B. Corrected linear sedimentation rates (LSR), total mass accumulation rates (MAR), and carbonate mass accumulation rates are calculated from the smooth age model, average dry density, and calcium carbonate concentrations at 1-m.y. intervals. FO = first occurrence, LO = last occurrence.