Garnet U-Pb geochronology and geochemistry reveal deposit types and fluid evolution: An example from the Dongguashan Cu-Au deposit, eastern China

•The Dongguashan mineralization may have formed from magmatic-hydrothermal fluids.•Garnet LA-ICP-MS U-Pb dating yielded ages of 135.9 ± 2.1 Ma, 135.6 ± 2.2 Ma, and 134.6 ± 1.4 Ma, which provide constraints on the alteration initiation.•Physicochemical conditions of hydrothermal fluids for Dongguashan garnet were constrained.