The contemporary geochemistry of uranium in the Gulf of Mexico Distributive Province

Abstract

This study concerned the contemporary geochemistry of uranium in the Gulf of Mexico and adjacent areas. Hundreds of samples were analyzed using the novel delayed neutron counting technique. Emphasis was placed on understanding man's effects on present day inputs and assessing the importance of various uranium sinks in the Gulf. Field and laboratory fertilizer studies indicate that (1) a linear relationship exists between phosphate and uranium in commercially processed fertilizers; (2) this linear relationship exists in the various processing steps of both the Florida and North Carolina phosphates; (3) from these linear plots 100% P₂O₅ has 380 ppm uranium, which is considerably higher than previous estimates from ore concentrations; (4) uranium enters runoff via dissolution of fertilizers as shown in weathering experiments; (5) high uranium concentrations in the Brazos River occur after early spring fertilization; (6) Ra²²⁶, a hazardous daughter product of U²³⁸, is in approximately 10% radioactive equilibrium with U²³⁸ in phosphate fertilizers; and (7) a reasonable balance exists between input and deposition when the estimated increment caused by fertilization is subtracted from the total soluble uranium input. ...