We report the discovery of native gold particles within evaporite sediments (halite, gypsum) from the Tarim Basin, China. These gold grains, exhibiting dendritic and nodular morphologies, are intergrown with salt minerals and likely precipitated from low-temperature (< 150 °C) brines at trace concentrations. This finding represents a rare observation of gold mineralization in an evaporative sedimentary environment, which contrasts with the conventional paradigm of gold deposits dominated by high-temperature hydrothermal fluids. Based on these observations, we propose a preliminary saline lake-type gold enrichment model linked to “cold-water” sedimentation, which, if corroborated by future discoveries, may expand exploration targets to evaporite-bearing sedimentary basins.

In recent years, the distribution of potassium salt resources in the Central Asia–Tarim Basin salt lake chain has shown an asymmetric pattern, and exploration efforts in the northwestern Tarim Basin have not seen significant progress. This study focuses on the central Bachu Uplift within the Central Asia–Tarim Basin salt lake chain. The characteristics of subsurface brines and indicators of potash formation are investigated. By examining various potassium exploration indices, such as the potassium–chlorine coefficient and magnesium–chlorine coefficient, along with comprehensive analysis of hydrogen–oxygen, sulfur, and strontium isotopes, this research serves to evaluate the potential for potash formation in the central Bachu Uplift. Analysis shows a brine salinity of 12.69–88.46 g/L and a potassium concentration of 0.07–0.65 g/L. The hydrochemical coefficients indicate a high nNa/nCl value, with low K × 10³/Cl values. All brine samples plot within the halite phase field of the 25 °C Na⁺,K⁺,Mg²⁺//C1⁻-H₂O Quaternary metastable phase diagram, clustering towards the Na-rich end. This indicates that the brine likely originated from halite dissolution. In the Na⁺,K⁺,Mg²⁺//C1⁻,SO₄²⁻-H₂O Quinary metastable phase diagram, the majority of samples project within the mirabilite phase field, trending toward the sylvite field. This suggests that the shallow subsurface brine may still be in the early to middle stages of sylvite deposition. Hydrogen and oxygen isotopes indicate that the brine samples were influenced by water–rock interaction and strong evaporative concentration; strontium isotopes reveal their marine–continental transitional characteristics; and sulfur isotopes suggest that the sulfur in the samples was derived from the weathering of Meso-Cenozoic gypsum in the western Tarim Basin. This integrated evidence implies that the brines in the central Bachu Uplift contain a deep-seated potassium anomaly, with fault zones likely conveying information about deep potash resources. This provides preliminary evidence for potassium exploration in the area and holds significant indicative value for identifying key prospective targets.