Multi-mineral U–Pb geochronology of the Ban Phuc disseminated Ni sulfide deposit, Ta Khoa District, northern Vietnam: Implications for genesis and exploration

Large Igneous Provinces are often associated with economic mineralization, such as nickel (Ni), copper (Cu), and platinum group element (PGE) deposits. Exploring these mineral resources relies on understanding the chronology of processes involved in deposit formation, as the timing can significantly affect both the concentration and accessibility of valuable minerals, thereby informing effective exploration strategies. Here we present new multi-mineral laser ablation inductively coupled mass spectrometry (LA-ICP-MS) U–Pb geochronology from the Ban Phuc disseminated Ni sulfide deposit in the Ta Khoa District in northern Vietnam. Zircon and monazite U–Pb isotopes suggest that the Ban Phuc intrusion was emplaced during the ca. 260 Ma Emeishan Large Igneous Province event, which likely also constrains the timing of addition of crustal S incorporation and sulfide liquid segregation and migration. Additionally, U–Pb apatite geochronology indicates apatite (re-)crystallization at ca. 220 Ma, in response to the Indosinian orogeny. Integration of the new geochronological ages with mineralogical and textural features based on investigation of thin sections and SEM-based automated mineralogy supports a model in which hydrothermal alteration of the deposit was not related to auto-hydrothermal processes. Rather, the widespread metasomatic rocks of the deposit likely formed through pervasive and channelized fluid flow during hydrothermal alteration driven by regional metamorphism, post-dating crystallization. Ultimately, this temporal framework allows discussion of the fate and potential redistribution of Cu, Ni, and PGE within the deposit, with implications for genetic models and exploration strategies. • Multi-mineral U–Pb geochronology study of disseminated Ni sulfide deposit. • Ban Phuc ultramafic intrusion emplaced at ~260 Ma during Emeishan LIP event. • Apatite U–Pb ages (212–241 Ma) indicate no autohydrothermal overprint. • Post-magmatic alteration linked to fluid flow during Indosinian Orogeny. • Results refine genetic models and improve exploration strategies for Ni–Cu–PGE.