Apatite fingerprints on the magmatic-hydrothermal evolution of the Daheishan giant porphyry Mo deposit, NE China

Abstract Porphyry deposits are the main source for global Cu and Mo production. The generation of hydrous silicate magmas subsequent separation volatile-rich magmatic fluids with hydrothermal alteration significant processes leading to formation porphyry deposits. However, a specific understanding these has been limited by lack direct mineralogical records in evolving magmatic-hydrothermal system. In this paper, we present an integrated textural geochemical investigation on apatite from giant Daheishan deposit NE China, illustrating that can be potential recorder evolution systems. Apatite ore-forming displays distinctive core-rim textures, melt inclusions resorption cores (Type-A1) co-existing fluid euhedral rims (Type-A2), indicating origin apatite. This is also supported both chemical isotopic compositions obtained situ analyses using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) LA-multi collector-ICP-MS. late Type-A2 relatively enriched incompatible elements, such as rare earth elements (REE) Th, but slightly depleted fluid-mobile Na S, compared early Type-A1 Relatively homogeneous (87Sr/86Sr)i ratios (0.70436–0.70504) apatites indicate they were formed closed system without detectable contamination. Meanwhile, some wall rock (biotite granodiorite) shows characteristics secondary altered resulting intensive exsolved trapped mineral phenocrysts usually unaltered (Type-B1 apatite), clear oscillatory growth zones cathodoluminescence (CL) images. contrast, intergranular commonly (Type-B2 chaotic zoning CL images, abundant micro-fractures inclusions. Compositionally, Type-B2 notable tetrad REE patterns, lower light-REE S contents, elevated 147Sm/144Nd Type-B1 LA-ICP-MS U-Pb dating yields intercept age 171.4 ± 2.3 Ma Type-B2, which consistent 171.5 2.4 Type-A2, notably younger than (175.5 1.3 Ma). It suggested significantly reset Therefore, conclude textures geochemistry systems used proxy recording exsolution processes.