Lithologic Mapping and Alteration Information Extracting Based on ASTER Spectral Signature: An Example from Nianzha Gold Deposit

Lithologic interpretation and alteration information extracting based on ASTER spectral analysis have been widely used in ore exploration.The authors carried out the study in Nianzha gold deposit of Yarlung Zangbo suture zone.Minerals components such as Fe³⁺, Fe²⁺, Al-OH, Mg-OH, silicate and carbonate were analyzed based on ASTER spectrum. This paper used "band radio method + false color synthesis" for lithologic classification and geological mapping and quantitatively delineated the range of mineralization-relatedalteration zone and two prospecting target areas with the "geologic-remote sensing profiles + best density seperation method". The results show that lithological mapping and alteration information extracting based on aster spectral are suitable for prospecting prediction in high altitude areas of Tibet, which can accurately indicate the key prospecting indicators of lithology and alteration.It proves to be an important means of rapid and effective ore exploration in Tibet, and provides reference for other deposits of the same type in the belt.