Physico-chemical control on the REE minerals in chloritoid-grade metasediments from a single outcrop (Central Alps, Switzerland)

►REE minerals are modified in samples containing veins. ►Fluid enhances REE minerals crystallization during deformation. ►Phosphates can incorporate significant As contents in low-grade metasediments. ►U-Th-Pb ages can record fluid interactions, deformation and/or oxidizing stages.