The Use of Portable X-ray Flourescence, Magnetic Susceptibility and Scanning Electron Microscope to Classify, characterize, and Determine Redox State of Granites

Utah contains granitic intrusions associated with various ore deposits that vary spatially, temporally, and chemically. Utah is a great location to study mineralization associated with granites because it encompasses three unique geologic provinces and offers a wide array of emplacement configurations. Past studies in Utah have primarily focused on major elements and there is also a paucity of trace analyses and most studies are only on one discrete location. Trace element analysis can be used for classifying granites and also locating potential mineralized granites. Trace element analysis of granites may also lend insight into magma redox, which is important for ore formation. Trace element and redox analyses are both expensive and time consuming. We wanted to determine redox and trace element distribution using tools that are cost effective and readily available. Portable x-ray fluorescence (pXRF) offers an affordable solution to quickly acquire large counts for key trace elements in granites. These semi-quantitative results may also help determine redox. We present a technique to better determine the redox state of granitic rocks using pXRF and magnetic susceptibility a tool that is underutilized in the field. Additionally, we show that mineral mapping of oxides and sulfur-bearing minerals in thin section by SEM, aids in determining the redox state of granites by looking at Fe and Ti ratios and observing the presence of sulfate or sulfide. By utilizing equipment that is readily available and cost effective we are able to better understand the redox state, and mineralizing potential of various granites. This is important to workers interested in locating ore deposits or understanding the granitic system.