Non-destructive REE determination by high-energy sub-micro XRF in aqueous alteration products and fluid bubbles and veins in the water-rich

The aim of this experiment is to investigate, in a non-destructive manner, the rare-earth element (REE) abundance and obtained concentration trends (e.g. light REE vs high REE, REE anomalies) in intense aqueously altered and fluid-rich regions found inside unique samples of the Winchcombe and Northwest Africa 6693 meteorites. These Ca, P-rich regions of interest correspond to the calcium phosphate minerals apatite and merrillite, which contain trace amounts (1-10 ppm) of REEs like Y and the lanthanide series (La-Lu). Quantified REE values normalised to early Solar System abundances reveal concentration trends which hint at which stage fluids started to mobilise on the water-rich parent bodies of these meteorites.