Between 10% and 40% of the Vanadium and Uranium entering the modern ocean as dissolved river input is eventually buried in sediments overlain by anoxic bottom water. Previous work by Dr. Mix and his colleague Dr. Emeron from the University of Washington has found that concentrations of V and U in foram tests have varied over the last 150 Kyrs. Provided the assumption is true tht formas incorporated these metals in equilibrium with seawater, this preliminary data suggests that bottom, water during the last glacial period was more oxygenated that at present, and that between Atlantic and Pacific bottom water was substantially different from that of today. In this renewal award the PIs will to continue their research in several directins: 1) they will perform culturing experiments with collaborator Dr. Erez in Israel to determine the uptake patterns of V and U in live forams; 2) they will improve solid source mass spectometry techniques for measuring V and U in single species of forams; and 3) they will apply these techniques to refine the history of anoxia in the world's oceans since the last interglacial
