Gravity gliding controls gold mineralization at the Shiqiaopu deposit, Xuefengshan Orogen, South China: Insights from structural analysis

• Gravity gliding drives orogenic gold at Shiqiaopu deposit. • Paleostress inversions prove gravity-induced stress overprint. • Ductile-brittle shear zones host auriferous pyrite via fault-valve cycling. • Metamorphic fluids dominate mineralization in décollement shear zones. Gravity gliding, a fundamental process in intracontinental orogens that governs strain localization and fluid migration, remains underexplored in its control on gold mineralization. This study elucidates its role at the Shiqiaopu deposit in South China’s Xuefengshan Orogen through integrated structural mapping, microtextural analysis, and electron backscatter diffraction (EBSD)-derived crystallographic preferred orientations (CPO). Late Triassic emplacement of the Baimashan pluton, superimposed on the earlier Indosinian orogeny, generated a restored paleotopographic gradient exceeding 700 m, initiating top-to-the-NE gravity gliding along a décollement in the Neoproterozoic metavolcaniclastic Shiqiaopu Formation. Paleostress inversions reveal three stress regimes consistent with this gravity-driven kinematics: (i) NW–SE Indosinian compression preserved in the basement (σ 1 ≈ 127°/12°); (ii) NE–SW extension in the proximal (up-dip) domain of the cover sequence (σ 3 ≈ 061°/21°); and (iii) NE–SW compression in the distal (down-dip) domain (σ 1 ≈ 056–068°/03–06°). This produced a coupled extensional-contractional framework, overprinting the regional NE–SW tectonic trend with deposit-scale NW-striking structures. Ductile shear zones within the décollement exhibit S-C fabrics, quartz dynamic recrystallization via bulging and subgrain rotation (∼250–450 °C), and syn -kinematic chlorite-sericite foliation, generating strong anisotropic permeability that channeled hydrothermal fluids. Periodic brittle ruptures formed oblique shear and extensional veins, trapping native gold in syn -kinematic pyrite along foliation and microfractures, reflecting a ductile–brittle regime analogous to fault-valve cycling. Bimodal grain orientation spread (GOS) distributions in quartz delineate low-GOS recrystallized (thresholds 0.80°–0.99°) and high-GOS relict populations, evidencing episodic nucleation and growth under cyclic pressure fluctuations. Contractional features, including thrust ramps and fold hinges, amplified fluid overpressure via basement-cover strain partitioning, concentrating ore at mechanical-chemical traps. This represents the first comprehensively documented field- and mine-scale case gravity gliding controlling auriferous shear zones in the Xuefengshan Orogen. The mechanism drives mineralization by reactivating décollement conduits, modulating permeability through syn -kinematic recrystallization and transitions, and focusing ore at coupled interfaces. These insights refine genetic models for orogenic gold systems and offer a robust exploration strategy targeting rheological contrasts and down-dip contractional domains in analogous intracontinental settings.