Hydrothermally altered mineral mapping of the Malanjkhand copper mineralization in India using Landsat satellite data

The study evaluates how Landsat-5 Thematic Mapper (TM), Landsat-7 Enhanced Thematic Mapper Plus (ETM+), and Landsat-8 Operational Land Imager (OLI) satellite data can be used to detect and map hydrothermally altered minerals in the Malanjkhand copper mines of Madhya Pradesh, India. By employing band ratio and principal component analysis (PCA) methods, the study generates detailed spatial distributions of hydrothermally altered rocks linked to porphyry copper mineralization in the region. The study also finds that the band ratio combinations and the PCA method effectively distinguished hydrothermally altered minerals, vegetation, and iron oxides in the satellite images. Furthermore, the research reveals that Landsat-8 OLI data outperformed Landsat-5 TM and Landsat-7 ETM+ data in detecting hydrothermally altered minerals using the PCA technique. The correlation of identified minerals with the satellite images from Landsat sensors, supported by spectroscopic and petrographic studies, underscores the comprehensive approach taken in this study to enhance the understanding of hydrothermal alteration zones and improve the efficiency of mineral exploration. In conclusion, the research emphasizes the suitability of Landsat-8 OLI data for visual interpretation of hydrothermal alteration mapping, highlighting its higher radiometric resolution and reduced interference between vegetation and altered minerals.