Interstitial-water geochemistry of Kerguelen Plateau sediments

Abstract

Sediments were cored at six sites (49°24′S to 59°36′S) in water depths ranging from 564 to 4082 m. A total of 77 interstitial-water samples was recovered as part of the routine sampling protocol. In addition, a novel, high-resolution pore-water sampling program was tested. Data collected include interstitial-water sodium, potassium, calcium, magnesium, pH, alkalinity, sulfate, ammonia, phosphate, aqueous silica, salinity, chloride, oxidation-reduction potentials, and sediment chemistry. The northern sector (Sites 736 and 737) is characterized by the highest sedimentation rates (up to 140 m/my) and thermal gradients (70°-98°C/km). The southern portion of the Kerguelen Plateau (Sites 738 and 744) records the lowest sedimentation rates (less than 5 m/my) and thermal gradients (43°C/km) of the three study area. -from Authors