Earth system science applications of next-generation SEM-EDS automated mineral mapping

Sedimentary rocks contain a unique record of the evolution Earth system. Deciphering this requires robust understanding identity, origin, composition, and post-depositional history individual constituents. Petrographic analysis informed by Scanning Electron Microscope - Energy Dispersive Spectroscopy (SEM-EDS) mineral mapping can reveal morphology petrological context each imaged grain, making it valuable tool in Scientist’s analytical arsenal. Recent technological developments, including quantitative deconvolution mixed-phase spectra (producing “mixels”), now allow rapid SEM-EDS-based broad range sedimentary rocks, previously troublesome fine-grained lithologies that comprise most record. Here, we test reliability preferred work flow modern Field-Emission scanning electron microscope equipped with Thermofisher Scientific Maps Mineralogy system, focusing on mud/siltstones calcareous shales. We demonstrate SEM-EDS implements 1) strict error minimization spectral matching approach 2) to produce ‘mixels’ for X-ray volumes robustly identify grains mineralogical data sets comparable conventional diffraction (XRD) ( R 2 > 0.95). The correlation between XRD-derived mineralogy is influenced abundance, processing modes mapped area characteristics. Minerals higher abundance (>10 wt%) show better correlation, likely result increased uncertainty XRD quantification low-abundance phases. Automated greatly reduces proportion unclassified pixels, especially fraction, ultimately improving identification quantification. Mapping larger areas benefits bulk analysis, while customized size shape allows high-resolution situ analysis. Finally, review applications Sciences, via case studies illustrating approaches differentiation various components detrital (allogenic), syndepositional (authigenic) burial diagenetic phases, origin significance lamination, 3) effectiveness appropriateness sequential leaching geochemical studies, 4) utility maps target within specific contexts or geochronological