Titanite links rare-element (meta-)pegmatite mineralization to Caledonian metamorphism

The metamorphic reworking of mineralized pegmatites during orogenesis remains unclear, making the genesis and tectonomagmatic significance pegmatite mineralization obscure. This study demonstrates multiple utilities titanite geochemistry in establishing Caledonian evolution world’s largest intra-plutonic Nb-Y-F Paleoproterozoic host rocks Tysfjord, Northern Norway. A combination titanite-specific barometry, Zr-in-titanite thermobarometry, U-Pb geochronology yields peak metamorphism ?12 kbar 730–750 °C at ?410 Ma for metamorphosed ( meta -pegmatite) region. In relation to published ages 410–400 other regional -pegmatites, interpreted as overprinting here, we argue that protoliths have undergone analogous rocks, which was caused by allochthonous nappe stacking late collisional orogeny (?440–400 Ma). Published formation ?400–380 undeformed are 10–30 younger than metamorphism, supporting an anatectic link post-collisional extension. led strong shearing preexisting bodies resetting trace elements isotopic systems constituent minerals via mineral re-crystallization, inheritance Pb components, element diffusion. cautions against interpretation -pegmatite-derived geochemical information terranes without detailed textural investigation.