Figure 9. Depth-age profile determined from geomagnetic reversals and diatom and radiolarian datums. Paleomagnetic data were drawn from analysis of split-core (X's) and geologic high sensitivity magnetic tool (GHMT) logging data (diamonds). Separate curves for split-core (thin line) and GHMT magnetic data (heavy broken line) are interpolations that pass through all data points within each data set and match the slopes at those points. Diatom and radiolarian datum intervals are marked with an upright triangle at the base (B = base/first occurrence) and an inverted triangle at the top (T = top/last occurrence). TC = top of common occurrence/last common occurrence. P. sulcata abundance is shown with gray shaded bars. The hole is barren of microfossils below ~520 mbsf. Mean sedimentation rates (underlined) determined for the three intervals show an uphole decrease.