Figure F20. Profiles of chemical constituents in interstitial water at Site 1258. A. Salinity. B. Chloride. C. Sodium. D. Potassium. E. Alkalinity. F. Sulfate. G. Ammonium. H. Barium. ICP-AES = inductively coupled plasma–atomic emission spectroscopy. "?" = a questionable data point. Shaded bar = the black shale sequence (Unit IV). I. Calcium. J. Strontium. K. Magnesium. L. Lithium. M. Boron. N. Silica. O. Iron. P. Manganese.