Figure F35. Concentration-depth profiles of SO₄^2-, pH, alkalinity, and NH₄⁺ at Site 1171. Methane concentrations (see "Volatile Hydrocarbons" in "Organic Geochemistry") are plotted for comparison. Alkalinity and pH values were not measured in many of the lithified siliciclastics samples in which pore-water volume was limited. Approximate locations of lithostratigraphic and biostratigraphic boundaries (see "Lithostratigraphy" and "Biostratigraphy") and standard seawater (SW) concentrations are indicated. Dashed lines mark depths of pronounced pore-water chemistry changes.