Application of ZY-1 02D hyperspectral data to altered mineral mapping and ore prospecting in desert areas along the northern margin of the Qaidam Basin

The geological exploration in Qinghai Province is conducted in typical highland desert areas characterized by significant terrain cutting, low vegetation cover, extensive bedrock outcrops, and challenging surface investigations. To investigate the application of hyperspectral data from a satellite in altered mineral mapping and ore prospecting in desert areas along the northern margin of the Qaidam Basin, this study utilized hyperspectral remote sensing images with high spatial and spectral resolutions obtained from the domestic ZY1-02D satellite. Following fine-scale radiometric calibration, atmospheric correction, data restoration, and orthorectification, high-quality hyperspectral remote sensing images were acquired for desert areas, such as Saibagou, along the northern margin of the Qinghai Province. After comprehensive field survey sampling and spectral testing using a FieldSpec Pro FR spectrometer, a standard laboratory spectral dataset of the surveyed areas was established, containing 13 major altered minerals such as chlorite. Finally, the extraction of altered minerals and ore prospecting were conducted. The results indicate that the primary altered minerals in the areas include 13 types: epidote, chlorite, albite, sericite, silicification, kaolinite, carbonate, limonite, actinolite, serpentine, hematite, pyrite, and malachite. The distribution of these altered minerals is closely associated with the strata, lithology of intrusions, and ductile shear structures. The analysis of the alteration characteristics of typical mineral deposits such as Saibagou reveals that malachitization, limonitization, pyritization, sericitization, and silicification are closely related to mineralization, being indicative of ore prospecting. Partial potassium feldspathization, chloritization, epidotization, and sodium feldspathization are also somewhat related to mineralization, serving as a valuable reference for ore prospecting. As a result of applying the above methods, combined with the 1:25 000 geochemical survey data, one copper-gold mineralized point was discovered in the Tuomoerrite area. Therefore, hyperspectral data-based alteration mineral mapping compensates for the limitations of traditional geological surveys and ore prospecting methods in the western desert areas of China with harsh natural conditions. This allows for rapid assessment of the regional geological setting and mineralization conditions, enabling the extraction of mineral spectral information. The hyperspectral data-based alteration mineral mapping provides abundant, fine-scale information for large-scale geological prospecting, offering broad application potential.