Remote sensing satellite-based structural/alteration mapping for gold exploration in the Ketté goldfield, Eastern Cameroon

In-situ mineral prospecting studies in the tropics face challenging environmental conditions leading to paucity of data and structural mapping of new mineralizations. Here we present the case of the tropical mining goldfield of Ketté in Cameroon to demonstrate remote sensing techniques for mineral exploration purposes. In this investigation Visible Near Infra-Red (VNIR) and Short Wave Infra-Red (SWIR) bands of Landsat-8 (OLI) and Landsat-7 (ETM+) images were used with field data for lineaments and hydrothermal alterations mapping. Semi-automatic and automatic extraction methods were applied through sobel directional filters to detect the contours in the image. PCA, MNF transformation and a band ratio of 4/2, 6/5 and 6/7 were applied to map alteration minerals. The result revealed NE-SW to ENE-WSW main trends. Gold mineralization occurrences are spatially associated with WNW-ESE to NW-SE (110°–140°) ranging lineaments/faults and show a strong correlation with medium to high lineament density zones. Hydrothermal alteration minerals are spatially associated closely with gold occurrences and known mining sites that are structurally controlled by the NE-SW to ENE-WSW shear zone. The high-prospect zones for gold exploration are located along the Mama and Molé fault, Ngoubésseli, Boubara-Koumbé Tiko, Gwé, and Ndambi I-Tezoukpé