The Study on Multi-Source Remote Sensing Alteration Information Extraction and Mineral Exploration Prediction in the Mayum Area, Tibet

In recent years, with the continuous advancement of Earth observation technologies both domestically and internationally, remote sensing has gradually become a crucial tool in geological surveys and mineral resource exploration. As a key target area in China's new round of strategic mineral exploration breakthrough initiatives, Tibet—with its sparse vegetation coverage and other unique geomorphological characteristics—offers favorable conditions for the remote sensing identification and extraction of alteration anomalies. This study focuses on the Mayum area in Tibet, employing a comprehensive approach that integrates multi-source remote sensing technologies to extract mineralization-related alteration information. By combining these data with 1: 200, 000 geochemical survey results, the study delineates favorable mineralization zones, further validated through field investigations to enhance understanding and interpretation of remotely sensed alteration signals. For data selection, this research utilizes multispectral data from Landsat-8 and Sentinel-2 satellites. Techniques such as Principal Component Analysis (PCA) and band ratio methods are applied to extract iron staining and hydroxyl alteration anomalies within the study area, and the threshold method is used to classify the intensity levels of these anomalies. Additionally, hyperspectral data from Gaofen-5 (GF-5) are processed using the Mixture Tuned Matched Filtering (MTMF) technique to identify various types of alteration anomalies, including limonitization, magnetitization, sericitization, and galenitization. The results from the multi-source remote sensing extraction are overlaid and compared with favorable metallogenic zones derived from the combination of isometric log-ratio (ILR) transformation and Robust Principal Component Analysis (RPCA) on the 1: 200, 000 geochemical data, as well as known mineral (mineralized) occurrences. As a result, several prospective exploration targets with significant mineralization potential are identified within the study area. Field validation further confirms the reliability of the remote sensing extraction methods employed in this research, providing both theoretical support and directional guidance for subsequent mineral exploration efforts in the region.