Combined micro X-ray fluorescence and micro computed tomography for the study of extraterrestrial volcanic rocks. The case of North West Africa (NWA) 8657: A shergottite martian meteorite
Carlo Porfido, Paola Manzari, Ignazio Allegretta, Roberto Terzano, Olga De Pascale, Giorgio S. Senesi
Volume 217, 1 September 2020, 121114
• μ-XRF and μ-CT were combined to describe the mineralogy and microstructures of the NWA 8657 Martian meteorite.
• μ-XRF and μ-CT allowed a non-invasive approach in mapping the spatial distribution of elements.
• μ-XRF and μ-CT were able to provide and unveil the processes involved in the meteorite formation.”
“The combined potentiality of benchtop micro X-ray fluorescence spectroscopy (μ-XRF) and micro computed tomography (μ-CT) has been applied to describe microstructures, type and distribution of mineralogical phases as well as geological constraints on the history of the North West Africa (NWA) 8657 shergottite Martian meteorite. The 3D rendering of the sample was used to compute its vesiculation, infer the presence of cracks and reveal different shapes in its crystal habits including subhedral pyroxene phases and rounded sulphide and/or sulphates minerals. Phase discrimination was achieved by comparing chemical information about element distribution with mineral classes segmented as a function of their relative density. In particular, the relationships between the plagioclase/maskelynite phase and other minerals such as Ca-phosphates, the chemical zoning of Ca-pyroxenes and maskelynite and the presence of S-bearing phases in the form of K-sulphates and Fe-sulphides were revealed, which allowed reconstructing satisfactorily meteorite history. The successful performance of the combined approach used in this work shows promising for further application to other types of meteorites.”