Petrogenesis of Late Cretaceous Muscovite-Bearing Peraluminous Granites in the Youjiang Basin, South China Block: Implications for Tin Mineralization

Most primary Sn deposits worldwide are associated with muscovite-bearing peraluminous granites, commonly believed to originate from the partial melting of metasedimentary rocks. We studied whole-rock geochemistry and Sm–Nd isotopes Late Cretaceous (~90 Ma) Laojunshan granites in Youjiang Basin, South China Block. The globally significant Dulong tin mineralization was co-genetic monzogranites. exhibit slightly higher εNd(t) values than Precambrian basement, indicating a hybrid crustal source comprising both rock juvenile components. Characterized by weakly compositions, these display highly evolved geochemical features: notably low levels Ca, P, Mg, Fe, Ti contents, elevated Si content, high FeOT/MgO ratio, Zr/Hf ratio. These distinctive features can be attributed differentiation plagioclase, biotite, zircons, remarkably Nb/Ta K/Rb ratios further suggesting fluid exsolution process. data propose that tin-enriched mineral crust-derived melts during magmatic evolution. By integrating novel findings existing on coeval it is deduced share unified origin. Their genesis rather direct