Tektites and microtektites iron oxidation state and water content

Fe redox and water content of impact melt are important parameters as they can greatly affect melt density and viscosity which, in turn, are important parameters greatly affecting the melt evolution and fate. In this manuscript I briefly describe recent research on X-ray absorption spectroscopy (XAS) determination of Fe oxidation state and micro Fourier transform infrared spectroscopy (FTIR) determination of water content putting them in the context of previous research done with different techniques. In comparison with other techniques requiring large amount of samples (e.g. potassium dichromate titration, Mossbauer spectroscopy, Karl Fischer titration), XAFS and micro FTIR techniques allow to study both macroscopic samples of tektites as well as smaller microtektites giving the same error, making it possible to compare results between tektites and micro-tektites and, consequently, also to find differences between tektites and microtektites or between microtektites from different strewn fields. A brief introduction on impact cratering and melt formation during impact events is aimed to introduce the subject to non specialised readers.