New Insights into the Geochemistry, Petrography, and Geochronology of Triassic and Cretaceous Granitoids in Kanchanaburi Province, Western Thailand: Implications for Magmatic Evolution and Metallogenesis

Geochemical, petrographic, and geochronological analyses of granitoids from Kan-chanaburi Province, western Thailand, reveal key insights into magmatic evolution and metallogenesis within the Western Granite Belt. U–Pb zircon dating identifies two main magmatic episodes: Late Triassic (227-214 Ma), and Late Cretaceous (79-68 Ma). The granitoids, including quartz monzonite, granodiorite, and quartz-rich gran-ite, are composed of quartz, plagioclase, K-feldspar, and biotite, with minor horn-blende and accessory minerals such as titanite, zircon, magnetite, ilmenite, and garnet. Magnetic susceptibility values (0.0001 × 10-3 to 0.0199 × 10-3 SI units) indicate pre-dominantly ilmenite-series granitoids, with localized magnetite-series occurrences. Geochemical data classify these intermediate to felsic plutonic rocks as calc-alkaline to shoshonitic, with a peraluminous, S-type affinity. U-Pb cassiterite and wolframite ages of 80-77 Ma suggest that W-Sn mineralization occurred during the Late Cretaceous at early-stage magmatism. The temporal and spatial distribution of these granitoids is closely linked to Pb–Zn–W–Sn mineralization, reflecting the influence of post-collisional magmatism on regional metallogenesis in the Sibumasu Terrane. This study refines the tectono-magmatic framework of western Thailand and underscores the importance of granitoid emplacement timing in controlling mineral deposit for-mation.