UV-visible spectrophotometer

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As metallic mineral deposits have become more difficult to find, strategies for their exploration have become increasingly dependent on genetic models which quantitatively describe the mechanisms of metal transport and deposition. In the case of hydrothermal ore deposits, development of these models depends heavily on the availability of thermodynamic data with which to evaluate the stability of aqueous metallic complexes at elevated temperatures and pressures. The applicant runs one of a small number of laboratories around the world that conduct the experiments needed to generate these thermodynamic data. Although metal speciation studies have been conducted successfully using the solubility method, this approach suffers from the fact that it is only possible to determine the thermodynamic properties of species, which are predominant under the experimental conditions. This limitation can be overcome using UV-visible spectrophotometry, which allows simultaneous evaluation of the thermodynamic properties of multiple species involving a particular metal and ligand. The applicant has been using this approach with considerable success, and recently completed the first and only comprehensive study of the behaviour of the rare earth elements (REE) in hydrothermal fluids, results of which are now finding widespread application in studies of topics as diverse as the metasomatism of the crust and the disposal of nuclear waste. This application seeks funds to replace a ten year old UV-visible spectrophotometer which has become unusable because of deterioration of the optical system. The new UV-visible spectrophotometer will have improved resolution permitting the generation of superior thermodynamic data, and will be used initially to investigate the speciation of cobalt, uranium and zirconium, studies that will contribute to improved ore deposit models for these deposits. More generally, the equipment will allow us continue to play an important role in supplying the scientific community with data that are essential to modelling the transport of metals in crustal fluids.