Raman microspectroscopic mapping with multivariate curve resolution-alternating least squares (MCR-ALS) of the high-pressure, α-PbO2-structured polymorph of titanium dioxide, TiO2-II

The recent identification of the high-pressure, α-PbO 2 -structured polymorph of titanium dioxide, TiO 2 -II, in grains recovered from four Neoarchean spherule layers has provided physical evidence to further support an impact origin of these layers. Smith et al. (2017) investigated these TiO 2 -II-bearing grains using Raman microspectroscopic mapping with multivariate curve resolution-alternating least squares (MCR-ALS) to spatially and spectrally resolve the individual chemical species within the grains. Here we provide the Raman microspectroscopic mapping data collected on the TiO 2 -II-bearing grains. We further provide chemical maps, chemical images and Raman spectra of rutile, TiO 2 -II, anatase, quartz, and substrate-adhesive epoxy that were resolved using MCR-ALS applied to the Raman microspectroscopic mapping data. The Raman microspectroscopic mapping data in this work—collected using both high spectral resolution and high spatial resolution—provides a myriad of opportunities for the scientific community in wide ranging applications, including the chemical imaging and chemometric disciplines.