Space weathering: Laboratory analyses and in-situ instrumentation

Simulations of space weathering using laser irradiation are exploited to study the formation of sub-microscopic iron. A variety of magnetic techniques are evaluated to characterise this iron and are considered for in-situ instrumentation

Spectroscopic examinations of hydro- and glaciovolcanic basaltic tuffs: Modes of alteration and relevance for Mars

Hydro- and glaciovolcanism are processes that have taken place on both Earth and Mars. The amount of materials produced by these processes that are present in the martian surface layer is unknown, but may be substantial. We have used Mars rover analogue analysis techniques to examine altered tuff samples collected from multiple hydrovolcanic features, tuff rings and tuff cones, in the American west and from glaciovolcanic hyaloclastite ridges in Washington state and in Iceland. Analysis methods include VNIR-SWIR reflectance, MWIR thermal emissivity, thin section petrography, XRD, XRF, and Mössbauer spectroscopy. We distinguish three main types of tuff that differ prominently in petrography and VNIR-SWIR reflectance: minimally altered sideromelane tuff, gray to brown colored smectite-bearing tuff, and highly palagonitized tuff. Differences are also observed between the tuffs associated with hydrovolcanic tuff rings and tuff cones and those forming glaciovolcanic hyaloclastite ridges. For the locations sampled, hydrovolcanic palagonite tuffs are more smectite and zeolite rich while the palagonitized hyaloclastites from the sampled sites are largely devoid of zeolites and relatively lacking in smectites as well. The gray to brown colored tuffs are only observed in the hydrovolcanic deposits and appear to represent a distinct alteration pathway, with formation of smectites without associated palagonite formation. This is attributed to lower temperatures and possibly longer time scale alteration. Altered hydro- or glaciovolcanic materials might be recognized on the surface of Mars with rover-based instrumentation based on the results of this study

Compositional Characterization of Glassy Volcanic Material From VNIR and MIR Spectra Using Partial Least Squares Regression Models

<p>This is supporting data for the paper titled "Compositional Characterization of Glassy Volcanic Material From VNIR and MIR Spectra Using Partial Least Squares Regression Models" by Leight et al. (submitted to JGR-P 11/23). Table S1 lists each spectrum used to train PLS models, its source, and which training datasets the spectrum was included in. Zip files contain the MIR and VNIR PLS model files. Model files are .asc, and can be run using the code at Ytsma, (2022), https://doi.org/10.5281/zenodo.7347345. </p&gt