Quantitative automated mineralogy to constrain metamorphic processes using ZEISS Mineralogic скачать в хорошем качестве

Quantitative automated mineralogy to constrain metamorphic processes using ZEISS Mineralogic

Quantitative automated mineralogy to constrain metamorphic processes using ZEISS Mineralogic Richard J M Taylor*, Chris Clark and Tim Johnson *E-mail: richard.taylor@zeiss.com The ZEISS Mineralogic automated quantitative mineralogy takes a new approach to automated mineralogy. Mineralogic uses a Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS) detectors, but following an analytical protocol more closely aligned with the quantitative Electron Probe Micro Analysis (EMPA). A combination of matrix corrections, peak deconvolution, and standard calibration means that peak intensities are converted directly into wt% element directly at the time of analysis. The result is a data output that can be immediately interpreted by both new and experienced users, even for minerals not previously in the database. Here the ZEISS Mineralogic system is demonstrated as a tool for automated mapping of thin sections from metamorphic terrains. The bulk chemistry of the entire thin section, as well as individual mineral compositions can be used to constrain P-T conditions directly from the SEM, without the need for an additional step of obtaining mineral chemistry from an EPMA. With quantitative analysis at every pixel, major element profiles can be obtained at any point in the thin section, and P-T can therefore be determined from any domain within the mapped section. This approach makes the use of P-T pseudosections possible with greater speed and flexibility than has previously been possible.