Mineralized Magmatic Hydrothermal Systems

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This specific research application focuses on complex infiltrative metasomatic reaction systems, which indirectly relates to the spectrum from magmatic volatile evolution through to the distal precipitation of associated metal complexes; this is an extension of my research on skarn systems that has had several key impacts, which most notably are: 1) some important phase relations have been highlighted in mixed volatile, infiltrative contact metasomatic systems, 2) permeability evolution during solution-host rock reaction coupled with the analysis of physio-chemical reactions, and 3) the provocative petrogenetic interpretation of some derivative igneous rocks, their gases, and eruptive/brecciation style has a wide range of implications. These contributions are all interrelated as the complex feedback mechanisms (i.e., CO2 back infiltration from decarbonation fronts) affect fluid-mineral-melt phase relations (i.e., lowering P(H2O)) that affect gas speciation, vapour saturation, and critical behaviour, metal partitioning, i.e., Fe, Cu, Au, W, Mo, etc. through to actual volcanic processes. This includes differential degassing at various pressures that can result in hypersaline fluids to salt or carbonate melts (some Fe-rich salt to carbonate melts) that may possibly explain some problematic genetic aspects of certain skarn-related deposit systems, i.e., magnetite-rich IOA & IOCG systems. Recent research of fluid reaction aspects that relate to silica activity relations in low to high T hypersaline systems shows silica activities vary widely, affecting proportion of calc-silicates formed with mineralization, which is critical to interpretation of many of these controversial systems. Mass-balance analysis of various infiltrative skarns compliments this research, although is definitely challenging; detailing the proportion of material added to and (or) removed from metasomatic systems helps to constrains the degree of fluid-rock reaction associated with infiltrative reaction metasomatic systems, the elemental mobility (fluid-rock ratios) observed, and the mechanisms responsible for these endo- and exo-contact reaction zones. The most provocative aspects reexamine the two end-member volatile fluxing and limestone-magma reactions during silicate magma interaction that are related to high-T magmatic skarn processes. These volatile fluxing to syntectic processes require a better understanding of complex high-T, skarn-forming processes, including mixed volatile infiltrative decarbonation equilibria and carbonate solubilities versus carbonate fluxing relations, open versus closed system reactions governing differential degassing of carbonated silicate, carbonate immiscibility, as well as their emplacement processes, including explosive pyroclastic volcanism; degassing significantly changes the P?V enhancing explosively of these systems. Rayleigh fractionation of O & C isotopes with radiogenic isotope mixing studies helps to constrain decarbonation processes.