Tracing detrital mineral sources is important for understanding economically prospective rare earth element (REE)-rich placers, but identifying their origins in complex geological settings remains challenging. Prospective amounts of detrital REE minerals occur in some of New Zealand's beach sands. However, other than coming from the actively exhuming Southern Alps, their sou-rces are poorly characterised. Here, we attempt to constrain the sources of a fluvial REE (xenotime and monazite) placer within this active orogen using textural, elemental and isotopic compositions of these and associated heavy minerals. Prominent Eu anomalies and U-Pb dating of xenotime (~101 Ma) and monazite (~112 Ma), along with their euhedral textures, are consistent with two distinct but proximal igneous sources. Garnet major element compositions also point to a magmatic source, and although Cretaceous plutons are outcrop extensively in the catchment, the detrital zircon population has only a very weak Cretaceous signal ( n = 6/121). Furthermore, although xenotime bulk rock εNd (i) compositions (average = −5.0) do align with local plutons, the ~101 Ma age is approximately 10 Myr younger than that of the known plutons. The xenotime source may therefore be a suite of granitic pegmatitic dikes that cross-cut these the plutons and gneisses. In contrast, the monazite ages overlap those of the locally dominant plutonic rocks but their in-situ εNd (i) values (−11 to +0.9) extend to much more radiogenic values. These data point to an as yet undiscovered proximal magmatic source rock with a strong depleted mantle component, in part mixed with crustal material to yield the spread in εNd. Although the specific sources of the REE minerals remain unknown, the mineral textures and isotopes strongly indicate that these sources are proximal, largely magmatic zircon-free, and not related to the most abundant mapped rocks in the region. Single grain textural, elemental and isotopic data therefore provide constraints on the origins of different mineral sources, and the implications of these data would be useful in future, advanced exploration. • Detrital REE minerals (xenotime and monazite) have distinct sources. • Geochemical characteristics indicate igneous origins. • Isotope compositions and age of minerals suggest hidden magmatic source. • Sedimentary inputs have varied in space and time in tectonically complex region.

The Xiatongling tungsten‑molybdenum‑bismuth (W-Mo-Be) deposit, located in the Nanling metallogenic belt, is a stockwork and quartz vein-type W-Mo-Be system developed within and along the contact zone of a medium- to fine-grained granite intrusion. Although previous studies have focused on the magmatic age and geochemical features of the intrusion, and indirectly constrained the mineralization age using molybdenite geochronology, the precise metallogenic chronology, sources of ore-forming materials, and key factors controlling W-Mo-Be mineralization remain poorly understood. This study presents an integrated geochemical and geochronological investigation of zircon, apatite, and wolframite from the deposit to constrain its petrogenesis and mineralization. The zircon U Pb age of the granite (ca. 154 Ma) corresponds to the wolframite U Pb age (ca. 154 Ma), establishing a genetic link between magmatism and tungsten mineralization. Geochemical data indicate that the granite is weakly peraluminous (A/CNK = 1.03 to 1.08), characterized by high SiO₂, U, and Ta, and low Ba, Sr, and Zr + Nb + Ce + Y, typical of highly fractionated S-type granites. Zircon ε Hf (t) values of −7.75 to −10.64 and apatite ε Nd (t) values of −15.56 to −8.97 indicate derivation from the Proterozoic metasedimentary basement of the Wugongshan area, which was characterized by pre-enrichment in W, Mo, and Be. Integrated whole-rock and wolframite geochemical data reveal consistent and pronounced negative Eu anomalies in both wolframite and the Xiatongling granite. Combined with robust geochronological constraints, these findings support the interpretation that the reduced ore-forming fluids were directly exsolved from the reduced, granitic magma. Based on the integrated evidence, we conclude that pre-enrichment of the source and extensive fractional crystallization were key factors for the formation of the Xiatongling W-Mo-Be deposit. • U–Pb ages show a link between Xiatongling mineralization and granitic magmatism. • Ore-forming fluids were directly inherited from the granitic magma. • The magma source originates from the Wugongshan metasedimentary basement. • Source pre-enrichment and fractional crystallization controlled W-Mo-Be deposit formation.

Continental to shallow marine sedimentary rocks were deposited along the Brazilian Atlantic margin during the Mesozoic-Cenozoic opening of the South Atlantic Ocean, following the breakup of West Gondwana. Within this context, the Miocene Barreiras Formation provides a key record of sedimentary processes associated with long-term tectono-sedimentary evolution. New detrital rutile U Pb data reveal a distinct Cambrian metamorphic signature at ca. 504 Ma, not previously identified, contrasting with the predominantly Neoproterozoic ages and complex fission-track signatures typically documented in detrital zircon and underscoring the potential of rutile as a complementary provenance and metamorphic tracer. The ca. 504 Ma detrital rutile ages are consistent with the timing of post-collisional collapse in the Araçuaí Orogen (~500–485 Ma), suggesting that this mountain belt constituted the main sediment source for the Barreiras Formation and that the rutile signature reflects the tectonometamorphic history associated with the Brasiliano Orogeny. Comparable Cambrian metamorphic ages reported from Pan-African belts in Angola and Namibia indicate that this thermal pulse extended beyond the Brazilian margin and was part of a broader transcontinental tectonothermal framework. The preservation of Cambrian ages in rutile is compatible with Pb diffusion and partial resetting of the U Pb system during high-grade metamorphism and subsequent lithospheric thinning in the Araçuaí Orogen, processes that record a phase of post-collisional reworking that mechanically weakened the lithosphere. In this sense, the Barreiras Formation not only documents Neogene sedimentary dynamics along the passive margin but also constitutes an archive of deeper crustal processes, bridging the Cambrian post-collisional collapse of the Brasiliano/Pan-African orogenic systems with the later Cretaceous onset of South Atlantic rifting and continental breakup. • Detrital rutile from the Neogene Barreiras Formation was investigated. • Detrital rutile U Pb age reveals a distinct Cambrian metamorphic signature at ca. 504 Ma. • Detrital rutile ages consistent with the timing of post-collisional collapse in the Araçuaí Orogen. • Comparable Pan-African Cambrian ages indicate thermal pulse beyond the Brazilian margin. • Cambrian ages compatible with Pb diffusion and U Pb partial resetting during high-grade metamorphism.