A Comprehensive program of research is planned that is centered on the oxygen isotope analyses of phosphate from both natural materials and various forms of apatite that will be synthesized in the laboratory. Specific goals are (1) the refinement of the method of preparation and isotopic analysis of phosphatic oxygen, (2) the experimental determination of the equilibrium oxygen isotope fractionation factors between dissolved phosphate and water and between various crystalline apatites and water over a very large range of temperatures from near Oo to 8OOoC, (3) the development of a single mineral oxygen isotope thermometer based on hydroxapatite and application to natural systems, (5) the use of 18O contents of teeth and bones to make important distinctions between marine and fresh water fish. Some novel techniques will be employed in conducting this research. The extraction of oxygen from very small samples of phosphate will be made with a laser fluorination system recently established at the University of Michigan. Catalysts will be used to obtain exchange equilibrium between phosphates and water at relatively low temperatures. Well crystallized hydroxy-and fluorapatite will be synthesized by a bacterial reaction in which enzymatic activity should promote attainment of isotopic exchange equilibrium. Obtaining reliable equilibrium fractionation factors in these systems over a large temperature range will be extremely useful in the resolution of a variety of petrological, paleoclimatological and paleoecological problems.
