Figure F31. Crossplots implying related processes in Hole 1208A. A. Ammonium vs. alkalinity. B. Phosphate vs. alkalinity. C. Phosphate vs. calcium. The correlation of the alkalinity vs. ammonium implies that ammonia is being generated as a by-product of sulfate reduction. Downcore phosphate concentrations appear to be dominated by two different processes. Phosphate data for interstitial waters between 0.0 and 147.2 mbsf are correlated with calcium data (R2 = 0.80) to show that precipitation of calcium phosphate may be occurring. The correlation between phosphate and alkalinity below 147.2 mbsf implies that degradation of organic matter is the major influence on phosphate concentrations lower in the core.

Figure F31. Crossplots implying related processes in Hole 1208A. A. Ammonium vs. alkalinity. B. Phosphate vs. alkalinity. C. Phosphate vs. calcium. The correlation of the alkalinity vs. ammonium implies that ammonia is being generated as a by-product of sulfate reduction. Downcore phosphate concentrations appear to be dominated by two different processes. Phosphate data for interstitial waters between 0.0 and 147.2 mbsf are correlated with calcium data (R² = 0.80) to show that precipitation of calcium phosphate may be occurring. The correlation between phosphate and alkalinity below 147.2 mbsf implies that degradation of organic matter is the major influence on phosphate concentrations lower in the core.