| This proposal is designed to integrate some of the most innovative aspects of modern petrology and geochemistry in order to constrain the relative contributions of the different source components that potentially contribute to magma genesis in subduction zones. The main geochemical reservoirs that play a role in the complex process of arc magma petrogenesis are the mantle wedge, fluids from the subducted slab and (partial melts of) subducted sediments or continental crust. One consequence of the complexity is that magmas frequently contain multi-populations of minerals derived from melts with markedly different petrogenesis. Using a detailed petrological approach involving melt inclusion and microprobe studies it is possible to recognise mineral populations within individual samples that show influence from the different components in the subduction environment. Once recognised, these distinct populations will be subjected to in situ state-of-the-art geochemical analysis to determine their genesis. Minerals with end member compositions will then undergo isotopic and high field-strength element (HFSE) analysis to constrain the source components, extent of partial melting and to determine the processes that produce the distinct geochemical signatures. This approach is designed to provide a far more detailed understanding of the complex physico-chemical processes that occur at destructive plate margins. |
