In the modified formula for the cubic law, the roughness correction coefficient C serves as a parameter that indicates the characteristics of the roughness of a rock’s surface. In this study, surface data for natural rock samples were acquired through high-precision 3D scanning and combined with publicly accessible CT scan data on rough rock fractures to generate spatial coordinates. The roughness correction coefficient C was calculated and analyzed using both formulaic and numerical methods. The analysis revealed significant effects of scale on the roughness correction coefficient for rock fractures within a size range of 5 to 10 cm (determined based on the actual sample size), with tensile fractures demonstrating greater variations compared to shear fractures. When calculating the roughness correction coefficient on the same fracture surface in different directions, significant directional effects were observed. Furthermore, elliptical fitting demonstrated favorable results. The conclusion drawn was that the roughness correction coefficient for fracture surfaces can be represented effectively using a tensor form, thereby simplifying the expression of directionality. Calculating and analyzing the fractal dimension of a rough surface further confirmed the existence of effects of size on roughness.

The oblique distribution of orebodies is a fundamental characteristic of the spatial arrangement of orebody groups in non-magmatic hydrothermal deposits and is closely related to shearing. The Daliangzi Pb–Zn deposit in the Sichuan–Yunnan–Guizhou Pb–Zn polymetallic metallogenic area is a typical representative of epigenetic hydrothermal deposits controlled by a strike-slip–fault-fold structure. However, the underlying ore-controlling mechanism of this strike-slip–fault-fold structure remains unclear; as a result, achieving breakthroughs in mineral exploration in the deposit’s deep and peripheral zones is directly hindered. This paper focuses on the Daliangzi Pb–Zn deposit. Based on the Theory and Methods of Ore-field Geomechanics, the hierarchical structural ore-controlling pattern of the deposit is clarified, identifying the NE-trending tectonic zone from the Middle-Late Indosinian to Early Yanshanian as the Pb–Zn metallogenic tectonic system. It proposes the spatial oblique distribution patterns of the deposits, ore sections, orebodies, and ore blocks, along with the mechanical mechanisms of multi-scale structural ore control. A compound negative flower structure–fault-fold–diapiric ore-controlling model was constructed for the Daliangzi Pb–Zn deposit. Finally, the locations of concealed orebodies at different scales within the Daliangzi Pb–Zn deposit and its surrounding areas were predicted; moreover, the locations of concealed orebodies at various depths within the deposit area were also predicted.

The Laoyingqing zinc deposit is located in the Pb-Zn deposit concentration district in northeastern Yunnan, with a geotectonic location on the southwestern edge of the Yangtze block. This deposit occurs in the interlayer fracture zone of the Huangcaoling Formation slate in the Middle Proterozoic Kunyang Group. In this deposit, zinc is significantly enriched compared to lead, and the sulfur isotopic composition of sphalerite shows δ³⁴S_CDT close to negative values. These characteristics are different from the common Pb-Zn deposits that occur in Sinian and Carboniferous carbonate rocks in northeastern Yunnan. The genesis of this deposit and its similarities to and differences from other Pb-Zn deposits hosted in carbonate rocks in the Sichuan–Yunnan–Guizhou Pb-Zn metallogenic triangle area (SYGT) need further research. This article selects typical rock (ore) samples for fluid inclusion, trace element, and H–O isotope analyses. The results show that (1) the homogenization temperature of the fluid inclusions is 130~306.5 °C, the salinity is 7.17 wt%~20.67 wt% NaCleq, and the density of the ore-forming fluids is 0.86–1.07 g/cm³. Overall, these ore-forming fluids belong to medium–low-temperature, medium–low-salinity, and medium–low-density ore-forming fluids, and they have reducibility. The fluid pressure is 36.3~85.6 Mpa, and the mineralization depth is 1.34~3.17 km. (2) The ore-forming fluids mainly came from deep-source metamorphic water and basin brine containing organic matter. (3) The ore-forming materials mainly came from the surrounding rocks (Kunyang Group). (4) The trace element characteristics of this deposit are different from sedimentary-exhalative type, magmatic hydrothermal type, and skarn type of Pb-Zn deposits, and have little difference from MVT Pb-Zn deposits. Based on the comprehensive analysis, this deposit is classified as a medium–low-temperature hydrothermal vein-type zinc deposit unrelated to magmatic activity. This study extends the ore-bearing surrounding rocks of Pb-Zn deposits in the SYGT to the slate of the Kunyang Group, enriching the regional Pb-Zn deposit mineralization theory and providing new ideas for mineralization prediction.