Abstract: The Xiaoluoshan molybdenum-polymetallic deposit occurs along the southern boundary of the Lingshan intrusive complex within the western Dabie orogenic belt. Mineralization exhibits intimate spatial association with granitic porphyry dikes, predominantly hosted within fractures and breccia zones of these intrusive bodies. The alteration mineralogy displays well-defined zoning patterns characterized by sericitization-argillization-pyritization assemblages, suggesting exploration potential for porphyry-style mineralization at depth. High-precision LA-ICP-MS zircon U-Pb geochronology yields an emplacement age of 117.66±0.74 Ma for the granitic porphyry dikes, corresponding to the middle to late Early Cretaceous. Comprehensive petrochemical analyses reveal the following characteristics: (1) elevated SiO₂ contents (72.75 %~78.54 %) with corresponding high alkali concentrations (7.99 %~9.82 %); (2) metaluminous- to weakly peraluminous compositions; (3) pronounced fractionation indices; (4) light rare earth element enrichment (ΣLREE/ΣHREE=5.94-12.78) accompanied by significant negative Eu anomalies; (5) enrichment of large-ion lithophile elements (Rb, Th) coupled with depletion of high-field-strength elements (Nb, P, Sr, Ti). Isotopic investigations demonstrate initial ⁸⁷Sr/⁸⁷Sr ratios ranging from 0.708 023 to 0.712 109 (Isr), εNd(t) values between −9.6 and −8.2, and two-stage depleted mantle model ages (TDM₂) of 1 802 Ma~1 664 Ma. Integrated geochemical and isotopic evidence indicates that these granitic porphyry dikes likely originated through partial melting of Meso- to Paleoproterozoic crustal materials at the northern Yangtze Block margin, with significant contributions from regional Dabie gneiss protoliths. Their formation is interpreted to have occurred in a post-orogenic extensional regime following Cretaceous post-orogenic extension.