The relationship between the cadmium concentration (Cd) and the stable carbon isotopic composition (S13C) of marine pore waters will be determined. These parameters are tightly correlated in the water column, but preliminary results suggest that this is not the case in the sediments. Release of cadmium to the pore water appears to be localized in a narrow zone close to the sediment-water interface, while isotopically light inorganic carbon continues to be added to the pore water below the near-interface zone of most intense organic matter composition. The motivation for the proposed research comes from efforts to compare the paleochemical records preserved in the stable carbon iosotope and cadmium: calcium ratios of benthic oraminifera tests. Quantification of the pore water Cd:SC13 relationship will make it possible to use enthic foraminiferal Cd:Ca data to test the hypothesis that the carbon isotope of some benthic foraminifera species reflects pore water carbon isotopic composition.
