Figure 2. Composite stratigraphic section for Site 997, with lithology, units, age, and shipboard total CaCO₃ contents (simplified from Paull, Matsumoto, Wallace, et al., 1996) and geochemical intervals defined by this study. In the lithology column, starting from the left, patterns represent calcareous nannofossils, diatoms, and clay. Shipboard total CaCO₃ is calculated from the inorganic carbon content given by carbon dioxide coulometry, assuring that all carbonate occurs as calcium carbonate.