Minerals

The Qulong–Jiama polymetallic ore concentration area, located in the eastern segment of the Gangdese metallogenic belt, is one of China’s most significant copper resource production zones. With the growing demand for copper resources, this area has become a key target for mineral exploration. The current study aims to explore the application potential of multispectral and hyperspectral remote sensing technologies in porphyry copper deposit prospecting, establish a hyperspectral remote sensing prospecting model tailored to this region, and provide technical support for prospecting prediction and resource exploration of similar deposits. Sentinel-2 and Landsat 8 data were used to outline major alteration anomalies at the regional scale, while GF-5 hyperspectral data enabled precision mineral mapping. Results show clear porphyry-style alteration zoning. Hyperspectral mineral identification reveals 33 mineralization- and alteration-related minerals, including muscovite, biotite, pyrophyllite, dickite, chlorite, epidote, and limonite. The ore concentration area exhibits a well-developed inner–middle–outer alteration sequence: (1) an inner potassic–silicic zone locally accompanied by skarn; (2) a middle phyllic and argillic zone dominated by quartz–sericite–pyrite assemblages; and (3) an outer propylitic zone of chlorite–epidote–carbonate with supergene iron oxides. These alteration patterns spatially coincide with known deposits and metallogenic structures such as faults, annular features, and intrusive contacts. Based on these spatial relationships, a hyperspectral remote sensing prospecting model was constructed. The model defines diagnostic mineral assemblages for each zone, highlights structurally altered overlapping areas as priority targets, and effectively predicts the distribution of ore-related alteration belts. The strong correspondence between remote sensing-derived anomalies and existing deposits demonstrates that hyperspectral alteration information is a reliable indicator of ore-forming systems. The proposed model not only provides a scientific basis for further prospecting and exploration in the Qulong–Jiama area but also serves as a reference for copper exploration in the Gangdese metallogenic belt and other similar porphyry–epithermal metallogenic systems.

The Micangshan lead–zinc deposits, located in the northern margin of the Sichuan Basin, are classified as the Mississippi Valley-type (MVT) deposits. This study investigates the genetic linkage between Pb–Zn mineralization and paleo-oil reservoirs in the region, which is distinct from separate investigations on lead–zinc deposits or paleo-oil reservoirs. Through mineralogy, isotope, and fluid inclusion analyses, it is revealed that the direction of ore-forming fluid migration and the ore-forming process are closely related to the thermal cracking of paleo-oil reservoirs. The deposits show a characteristic clustered distribution along the southern part of the Micangshan area, with high-grade mineralization concentrated in the Nanmushu and Kongxigou Pb–Zn deposits. Rb–Sr isotopic dating indicates that mineralization occurred during the Late Cambrian to Early Ordovician (Nanmushu deposit 486.7 ± 3.1 Ma; Kongxigou deposit 472 ± 6.1 Ma), coinciding with the formation of the first-stage paleo-oil reservoirs. The study concludes that the MVT Pb–Zn mineralization in the Micangshan area is genetically linked to the first-stage paleo-oil reservoirs’ hydrocarbon generation and migration events. The organic-rich hydrothermal fluids facilitated the migration and precipitation of Pb–Zn minerals.

The northern part of the Naomugeng Sag in the Erlian Basin shows favorable sandstone-type uranium mineralization in the lower member of the Saihan Formation. The sandstone thickness ranges from 39.67 to 140.36 m, with an average sand content ratio of 76.33%, indicating broad prospecting potential. This study focuses on samples from uranium ore holes and uranium-mineralized holes in the area, conducting grain-size analysis of uranium-bearing sandstones, heavy mineral assemblage analysis, and detrital zircon U-Pb dating to systematically investigate provenance characteristics. The results indicate that the uranium-bearing sandstones in the lower member of the Saihan Formation were primarily transported by rolling and suspension, characteristic of braided river channel deposits. The heavy mineral assemblage is dominated by zircon + limonite + garnet + ilmenite, suggesting that the sedimentary provenance is mainly composed of intermediate-acid magmatic rocks with minor metamorphic components. Detrital zircon U-Pb ages are mainly concentrated in the ranges of 294–217 Ma (Early Permian to Late Triassic), 146–112 Ma (Middle Jurassic to Early Cretaceous), 434–304 Ma (Late Carboniferous to Early Permian), and 495–445 Ma (Middle–Late Ordovician to Early Silurian). Combined with comparisons of the ages of surrounding rock masses, the provenance of the uranium-bearing sandstones is mainly derived from intermediate-acid granites of the Early Permian–Late Triassic and Middle Jurassic–Early Cretaceous periods in the southern part of the Sonid Uplift, with minor contributions from metamorphic and volcanic rock fragments. The average zircon uranium content is 520.53 ppm, with a Th/U ratio of 0.73, indicating that the provenance not only supplied detrital materials but also provided uranium-rich rock bodies that contributed essential metallogenic materials for uranium mineralization. This study offers critical insights for regional prospecting and exploration deployment.