The Jinchuan area is located along the northeastern margin of Longshou Shan, in the western part of the North China Plate. Since the Paleoproterozoic period, it has undergone complex geological evolution. A systematic analysis of the tectonic evolution in this region reveals key information about the tectonic background and evolutionary characteristics since the Paleoproterozoic period and serves as a crucial approach for understanding metallogenic processes and achieving breakthroughs in deep mineral exploration. Based on detailed field investigations, this study analyzes the structural characteristics of the area, focusing on conjugate shear joints, folds, and faults. Combined with previous research findings, the evolution of the tectonic stress field is analyzed. The results indicate that the orientation of the maximum principal stress underwent the following six distinct phases of change: nearly north-south (NS) → nearly east-west (EW) → nearly north-south (NS) → north-northeast-south-southwest (NNE-SSW) → northwest-southeast (NW-SE) → northeast-southwest (NE-SW). Integrating these results with the regional tectonic framework, the study systematically reconstructs the tectonic evolution of the Jinchuan area. This research provides important scientific insights and practical value for enhancing geological understanding of the region and guiding mineral resource exploration and development.

The Yawan gold deposit, located in the Western Qinling Orogen, contains gold mineralisation that is predominantly controlled by approximately east-west-trending fault systems. This study integrates field geology, petrography, cathodoluminescence imaging, electron probe microanalysis of gold-bearing minerals (pyrite and arsenopyrite), and in situ laser ablation U-Pb dating of calcite to constrain the timing of mineralisation and to elucidate the mechanisms of gold enrichment. This study reveals that the deposit is significantly structurally controlled and comprises two discrete mineralisation stages: a quartz-pyrite (Py1)-arsenopyrite (Apy1)-chalcopyrite assemblage (Stage 1), and a quartz-calcite-pyrite (Py2)-arsenopyrite (Apy2)-stibnite-sphalerite-galena assemblage (Stage 2). Py1 displays distinct zonation, with rim As contents notably higher than core values, while Co and Ni contents gradually decrease from core to rim. Py2 is characterised by high As (0.00%–4.72%), low Fe/S ratios, and a porous texture, containing gold and arsenopyrite inclusions. Invisible gold occurs in lattice-bound form in both Py1 and Py2. The As-Fe-S ternary diagram of pyrite indicates that Au⁺ likely entered the crystal lattice as a solid solution. Arsenopyrite geothermometry yields a mineralisation temperature of 389 ± 44 °C, and sulfur fugacity (ƒS₂) decreased markedly from Stage 1 to Stage 2. Combined with the S and Fe characteristics of pyrite, these features support a medium-temperature metamorphic hydrothermal environment. U-Pb dating of calcite from Stage 2 yields an age of 215.6 ± 7.1 Ma. In summary, the Yawan gold deposit belongs to the orogenic gold system, with its gold precipitation and enrichment controlled by sulfidation triggered by Late Triassic tectono-fluid activity.

The Western Qinling Orogen (WQO) is a major gold region in China, with gold reserves exceeding 1, 200 tons. Its complex topography, climate, and semi-humid grassland cover provide an ideal setting for evaluating deep-penetrating geochemical (DPG) methods. In this study, three DPG methods-the Fine-Grained Soil Prospecting Method (FGSPM), leaching of mobile forms of metals in overburden (MOMEO), and soil gas geochemical survey (H₂S, SO₂, and CO₂)-were employed in the southern Zhaishang concealed gold deposit, which is covered by semi-humid grassland and various overburden materials. Results indicate that no single method reliably identifies concealed orebodies or alteration zones, yet their combination improves detection, especially for deep and thin ores. Gas geochemistry exhibits higher sensitivity. Differences in response between FGSPM and MOMEO likely stem from variations in sampling and chemical analysis. For FGSPM, fine-grained soil fractions (< 75 μm and 75-125 μm) exhibit similar capacities for adsorbing mobile Au, predominantly occurs in water-soluble and clay-adsorbed forms, with strong spatial heterogeneity. H₂S and SO₂ serve as effective gas indicators in semi-humid regions, though uncertainties affected by various factors (e.g., biological activity) require further verification. These findings offer a valuable case study for DPG applications and enhance the understanding of geochemical exploration in covered terrains.

Addressing capacity assessment uncertainties in high-geological-background areas, this study develops a source-oriented risk assessment framework integrating spatial interpolation, source apportionment, and dynamic capacity modeling. Analysis of 39 surface soil samples (As, Cr, Ni, Cu, Zn, Cd, Pb, Se, pH) from Ankang Basin, China, reveals: Two heavy metal sources were quantitatively identified via APCS-MLR. Natural sources (71.94%) dominate, contributing Se, Cd, Cu, Zn, and Ni, with Cd primarily geogenic. Anthropogenic sources (28.06%) from industrial, transportation, and agricultural activities contribute Cr, As, Pb, and Ni. Static capacity assessment identifies Cd as the primary limiting element (average capacity 0.22). Dynamic model predictions indicate that the 20-year dynamic capacity of all elements is only 14–20% of the theoretical static capacity (Q_i), representing 16–47% of the current existing capacity, and will approach dynamic equilibrium after 40 years. Source-oriented capacity indices reveal natural sources pose the highest comprehensive risk (SPI = 0.916), mainly driving Cd capacity stress (SPICd = 0.34). Anthropogenic sources remain safe (SPI > 1.255) but warrant Pb monitoring. This framework supports precise management of selenium-rich lands, shifting strategies from emission control to avoiding high-risk geological units.