The　Veliki　Krivelj　large　porphyry-skarn　Cu　deposit　in　Serbia　is　located　in　the　Timok　metallogenic　district　on　the　western　margin　of　the　Tethyan　metallogenic　domain.　The　ore　bodies　are　predominantly　hosted　in　altered　andesite,　quartz　diorite　porphyry,　skarn　and　marble,　and　are　structurally　controlled　by　NNW-trending　faults.　Previous　studies　have　focused　on　porphyry　Cu　mineralization,　while　systematic　understanding　of　skarn　Cu　mineralization　remains　limited.　Based　on　detailed　geological　investigations　of　skarn　orebodies,　this　study　focuses　on　the　geochronology　and　elemental　geochemistry　of　garnet　within　them.　Detailed　petrographic　investigations　reveal　that　garnets　occur　in　three　lithological　units:　tuffaceous　hornfels　(Grt　I),　quartz　diorite　porphyry　(Grt　II),　and　marble　(Grt　III),　exhibiting　multistage　compositional　zoning:　(1)　Grt　I　displays　core-to-rim　evolution　from　Grt　Ia　(Gro69-75And25-30)　→　Grt　Ib　(Gro44-63And34-55)　→　Grt　Ic　(Gro0-14And86-99),　marked　by　progressive　depletion　in　grossular　(Gro)　and　enrichment　in　andradite　(And);　(2)　Grt　II　transitions　from　Al-rich　cores　(Grt　IIa:　Gro33-46And52-66)　to　Fe3+-dominant　rims　(Grt　IIb:　Gro1-9And90-98);　(3)　Grt　III　comprises　pure　andradite　(Gro0-4And95-99).　Trace　element　analyses　indicate　that　Grt　Ia　and　Grt　Ib　display　weak　HREE　enrichment　with　LREE　depletion,　weak　or　absent　Eu　anomalies,　and　uniform　Y/Ho　ratios,　suggesting　formation　in　a　reduced,　low　water/rock　ratio,　near-neutral　closed　system　dominated　by　magmatic　fluids.　In　contrast,　Grt　Ic,　Grt　IIa,　Grt　IIb,　and　Grt　III　exhibit　LREE　enrichment　with　HREE　depletion,　pronounced　positive　Eu　anomalies,　and　variable　Y/Ho　ratios,　indicative　of　formation　in　an　oxidized,　high　water/rock　ratio,　weakly　acidic　open　system　involving　both　magmatic　fluids　and　variable　contributions　from　meteoric　water.　Garnet　U-Pb　dating　constrains　skarn　Cu　mineralization　at　86.4　±　1.9　Ma,　coeval　with　porphyry　mineralization　(∼88　Ma)　and　quartz　diorite　porphyry　emplacement　(85–87　Ma).　Comprehensive　analysis　suggests　that　the　porphyry　and　skarn　mineralization　belong　to　the　products　of　the　same　magmatic-hydrothermal　mineralization　system,　and　the　quartz　diorite　porphyry　may　be　the　parental　rock　of　the　Veliki　Krivelj　skarn.　This　study　provides　critical　mineralogical　constraints　for　guiding　further　exploration　in　the　mining　area.　©　2025