Upgrade of the Scanning Electron Microscope Lab at the Arizona LaserChron Center

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This award provides funding to acquire three new instruments that will be used to determine the chemistry and structure of minerals which record a variety of geologic events and processes. The instruments will be utilized in the Arizona LaserChron Center (ALC), which is an NSF-supported community facility that supports research in Earth Sciences. Science questions addressed by ALC researchers focus on reconstructing the history of igneous activity (e.g., volcanic eruptions), formation of ore deposits, uplift of mountain ranges, accumulation of sediment and formation of associated hydrocarbon resources, evolutionary changes, early evolution of the Earth, Moon, meteorites, and Mars, history of Earth’s climate (e.g., patterns of ice sheets), and archaeological trade routes. The new instruments will be utilized to support the research of ~350 faculty members, professional geologists, and students per year. Supported activities include generating the images and analyses that are needed for NSF-funded projects, providing opportunities for researchers to learn the theory and methods of instrument operation, and offering educational and outreach activities for under-represented minority participants. The requested instruments consist of (1) an Energy Dispersive Spectroscopy (EDS) detector, (2) an Electron Backscatter Diffraction (EBSD) detector, and (3) a Raman spectroscopic system. The EDS and EBSD detector systems will replace the outdated systems which were acquired with our Scanning Electronic Microscope (SEM) in 2009. These instruments, combined with the new “AZtec Live/HKL” software included with the Instruments, will provide the chemical and structural information needed for ALC researchers to conduct cutting-edge research in geochronology, petrochronology, and thermochronology. New capabilities in microstructural analysis will also be enabled. The Raman system, combined with the “Correlate” software package offered by the manufacturer, will provide powerful new capabilities of chemical mapping and phase identification. Collectively, these enhanced capabilities will provide the images and analyses needed by ALC researchers more efficiently, at lower cost, and with enhanced resolution, and will also allow ALC researchers to explore exciting new science applications regarding: (1) the spatial context of in situ geochronometric minerals, (2) 4D evolution of shear zones, (3) use of baddeleyite for chronologic and chemical studies of mafic rocks, (4) processes of Pb loss in minerals, (5) provenance of detrital minerals, (6) many processes that control modal abundances, sizes, shapes, and orientations of minerals in various rock types, and (7) application of elastic thermobarometers to study a variety of geologic processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.