Figure F9. Strontium isotope ratios from pore water samples from Site 1039 are indicated by data points and the solid line, with the dashed line showing the strontium seawater curve appropriate to the sediment age. Note the basal pore water trend toward modern seawater composition, with values greater than Miocene seawater, indicating a strong seawater component in basement fluids. Similar variations are seen in calcium and strontium concentration data.