Geochemical Behavior and Distribution of Copper and Iron in Marine Waters

• Main Author: Symes, James Leo, III
• Format: Text
• Language: unknown
• Published: DigitalCommons@URI 1983
• Subjects: North West Atlantic; Northwest Atlantic
• Online Access: https://digitalcommons.uri.edu/oa_diss/1343; https://doi.org/10.23860/diss-symes-james-1983; https://digitalcommons.uri.edu/context/oa_diss/article/2356/viewcontent/Diss_Symes_III_James_1983.pdf

This thesis consists of three studies related to trace-metal marine geochemistry. The first investigation deals with the distribution of iron in the Northwest Atlantic. The second portion is a study comprising a series of physicochemical laboratory measurements aimed at characterization of the heterogeneous equilibrium of malachite (Cu2(OH)2CO3). This work is presented in two reports. The first deals with the experimental results in terms of equilibrium constants and related thermodynamic parameters while the second addresses the geochemical significance of these findings. The last portion of the thesis research is an investigation of copper(II) interaction with carbonate species with emphasis on the inorganic speciation of copper in seawater. Trace-metal samples from eleven stations in the Sargasso Sea, Slope Water, and continental shelf water of the North West Atlantic were analyzed for total dissolvable iron by atomic-absorption spectrophotometry. Vertical profiles for iron and associated temperature and nutrient data were obtained at five open-ocean stations. Data from six stations provided a transect across the continental shelf into the apex of the New York Bight. At open-ocean stations, iron was depleted near the surface to levels of about 1-2 nmol/kg and increased to levels of about 4-7 nmol/kg in the vicinity of the oxygen minimum. A characteristic bottom-water maximum was observed at stations where closely-spaced near-bottom sampling was conducted. This feature was at least partially due to resuspension of particulate iron associated with the nepheloid layer. Comparison of total dissolvable iron concentrations to those of filtered samples at one Slope Water station indicated that 38% of the available iron in the water column was associated with the particulate phase. Near the surface, in the vicinity of the chlorophyll maximum, iron was present almost totally in particulate form. The dissolved fraction increased to approximately 50% at the nutrient maximum and approached 100% in the mid-portion of the ...