Whiteschists from the Dora-Maira massif (Western Alps, Italy) are Mg and K-rich metasomatised granites which experienced ultra-high-pressure metamorphism and fluid–rock interaction during Alpine continental subduction. The sources and timing of fluid infiltration are a source of significant debate. In this study, we present boron (B) isotopes and other fluid-mobile trace-element (FME) concentrations in various generations of p...