## 1 Introduction  
The mapping of mineral alteration primarily relies on hyperspectral measurement techniques, but the shortwave infrared (SWIR) band is the most sophisticated and popular technique [1; 2; 3]. The commonly used technologies for high-resolution SWIR and near-infrared mineral measurements include the Portable Infrared Mineral Analyzer (PIMA) from Australia, the TerraSpec(r) Halo handheld analyzer developed by ASD in the United States, and the PNIRS system produced by the Nanjing Institute of Geology and Mineral Resources in China [4; 5; 6; 7; 8; 9; 10; 11]. In recent years, SWIR spectroscopy has been successfully applied in the exploration and prospecting of porphyry, shallow low-temperature hydrothermal, and skarn-type deposits [4; 5; 6; 7; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21], and remarkable results have been achieved in the discovery of concealed ore bodies as well as the deep and peripheral mining areas [12; 13; 14; 15; 16; 17; 18; 19; 20; 21]. SWIR spectroscopy is characterized by no need for sample preparation, short testing time, convenience, and speed. Compared to traditional mineral identification methods, it can effectively save on sample preparation and testing time, while also better controlling the cost of testing work [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15]. Previous studies of SWIR's application have covered areas such as Rodalquilar in Andalusia, Spain; Hauraki in New Zealand; Cananea in Mexico; Mongolia; Thailand; Hawaii in America; Zijin Mountain in Fujian Province; Nuri, Demingding, Tiegelongnan, and Niancun in Xizang Autonomous Region; Tonglushan in Southeast Hubei Province; East Tianshan in Xinjiang Uygur Autonomous Region; and Wunugetushan and Ganzhuershande in Inner Mongolia Autonomous Region, and significant results have been achieved. [PERSON] et al. show the case of the Rodalquilar epithermal system of the southern Spanish Gabo de Gata volcanic area using HyMAP airborne hyperspectral images [3]. [PERSON], [PERSON], shows most illite has a crystallinity value of \(>\)1.1 and illite-smectite \(<\) 1.1 as calculated from reflectance spectra, and a general increase in crystallinity value with depth [4]. [PERSON], [PERSON], shows the application of reflectance spectroscopy at the Cananea Cu-porphyriny deposit, Mexico [5]. [PERSON], [PERSON], shows PIMA is the only method for obtaining first-hand information on the mineral composition in the field [6]. [PERSON], [PERSON], et al. successfully identified a wide variety of phyllosilicates, zeolites, opal, calcite, iron oxides, and hydroxides and noted depth-associated changes in alteration minerals, patterns, or zones [7]. [PERSON] et al. used the crystallinity index of illite (ISM) and the absorption peak position of illite at 2200 nm as indicators for the discovery of a copper-molybdenum mineralization section in Zijin Mountain [14]. The Gangdisie metal-logenic belt in Tibet includes several porphyry and shallow low-temperature hydrothermal deposits, such as Qulong, Jiama, Nuri, Demingding, Tiegelongnan, Niancun, and Sinong. The studies have involved minerals such as muscovite, illite, alunite, kaolinite, and chlorite. By extracting features from the spectral curves and analyzing the spatial variation patterns, the hydrothermal mineralization centers can be determined [15; 16; 17; 18; 19; 20]. [PERSON] et al. proposed that the high Fe-OH characteristic absorption peak value of chlorite (Pos2250 \(>\) 2253 nm) indicated the mineralization center of the skam-type deposit in Tonglushan [15]. [PERSON] et al. concluded that the seritic alteration zone near the greenstone belt with an absorption peak of chlorite Fe-OH \(>\) 2253 nm can serve as an indicator for the exploration in the Yuhai copper ore district of East Tianshan, Xinjiang [18]. [PERSON] et al. analyzed the SWIR and thermal infrared spectra of borehole core samples to study the alteration and crystallinity of illite-sercite from the Wunugetushan and Ganzhuershande porphyriny-hydrothermal deposits in Inner Mongolia [21; 22].