基于GF-5高光谱数据的新疆雪米斯坦东段热液蚀变提取与铀成矿远景预测OA

Hydrothermal alteration serves as one of the crucial indicators of hydrothermal activity and metallogenic processes.Based on GF-5 hyperspectral data,this study employs techniques such as Spectral Angle Mapper(SAM),Spectral Feature Fitting(SFF),and Mixture Tuned Matched Filtering(MTMF)to extract hydrothermal alteration and analyze alteration mineral assemblages in the volcanic rock area of the eastern Xuemisitan region,Xinjiang.On this basis,uranium prospecting target areas are predicted.The results indicate that the hydrothermal alteration in the eastern Xuemisitan region is predominantly sericitization(including high-,medium-,and low-aluminum sericite),followed by chloritization and the presence of iron oxides/hydroxides.Spatially,these alterations are mainly distributed along near-NW,near-EW,and NE trending structural belts,exhibiting banded,patchy,and locally superimposed patterns.The assemblage of high-aluminum sericite and iron oxides is primarily developed at fault intersections,volcanic rock fracture zones,and near the contact zones of certain intrusive rocks,reflecting relatively high-temperature and acidic hydrothermal metasomatism coupled with subsequent oxidation.Conversely,the sericite-chlorite assemblage is commonly found in intermediate to mafic volcanic host rocks,indicating medium-to low-temperature hydrothermal metasomatism.Integrating the metallogenic model,ore-controlling factors,and alteration characteristics of known uranium deposits within the Xuemisitan metallogenic belt,this study suggests that the eastern segment with the combination of high-,medium-,and low-aluminum sericite,chlorite,iron oxides/hydroxides,and structural intersections/volcanic-intrusive rock contact zones represents favorable metallogenic domains.Consequently,one key prospect area,two secondary prospect areas,and one general prospect area have been delineated.This research demonstrates that GF-5 hyperspectral data can provide an effective basis for hydrothermal alteration extraction and uranium prospecting prediction in the eastern Xuemisitan region.