Of ten Leg 13 sites studied by us, eight give definite evidence of the existence of halite-containing sediments beneath the seabed. This conclusion is based on the existence on continuous sodium and chloride enrichments in interstitial waters with depth. This is the only direct evidence of the existence of salt at these sites, for only evaporitic dolomite, gypsum, and/or anydrite were recovered in cores. Among other ionic relationships, influence of evaporites is seen in calcium, magnesium and sulfate concentrations. Record high barium (216 ppm) and strontium (345 ppm) concentrations were observed in sulfate depleted pore fluids of Site 128 in the Hellenic Trench.