Hydrothermal alteration mapping and mineralization potential assessment in the Taznakht region (Morocco) through integrated ASTER imagery, airborne radiometric and magnetic data

Mapping hydrothermal alteration zones is a key step in mineral exploration because they often mark subsurface mineralization and the concentration of economically valuable metals. Hydrothermal processes can lead to the concentration of economically valuable metals, making alteration zones important exploration targets. This study focuses on the Taznakht area in the Anti-Atlas region of Morocco, where a combined remote sensing and geophysical approach was used to locate potential mineralized zones. ASTER satellite images and airborne gamma-ray spectrometry data were analyzed to support mineral exploration. Radiometric mapping revealed the distribution of potassium (K), equivalent uranium (eU), and equivalent thorium (eTh), as well as derived indicators like the K/eTh ratio and the F-parameter, which are useful for identifying hydrothermal alterations. In parallel, ASTER band ratio techniques were used to map minerals related to argillic, phyllic, and propylitic alterations, along with iron oxides. Structural data, including geological faults and magnetic lineaments, are interpreted as preferred pathways for hydrothermal fluid circulation. The integration of these datasets using a geometric average model, selected for its ability to balance the influence of heterogeneous datasets, led to the creation of a mineral prospectivity map. This map highlighted four areas of hydrothermal alteration that showed a strong spatial correlation with known mineral occurrences (63.63 %). Field observations confirmed the geological importance of these zones, showing that this approach can be applied to similar metallogenic provinces in the Anti-Atlas and worldwide to effectively guide future mineral exploration.