The discovery of natural resources remains the main mission of Earth observation satellites, especially in geographical areas that have a very difficult accessibility as those of the Bou Azzer–El Graara inlier (Central Anti-Atlas, Morocco). This work investigates the use of different satellite data, such as Sentinel-2A’s multispectral imagery, in order to direct the prospection program in an efficient manner, saving both time and cost. The image processing methods of Landsat 7, 8, and “Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)” (30 m/15 m) were used to create methods for Sentinel-2A images (10 m). The red, green, blue (RGB) image 12.8.2, 11/12.11/2.11/8, principal component (PC) 1,2,3(11.12.2), and other new images were the result of principal component analysis (PCA), and classification by the Iterative Self-Organizing Data Analysis Technique (ISODATA) and K-Means allowed realization of a lithological cartography as well as maps of lineaments through directional filters and the ratio of 11/12 for hydrothermal alteration zone mapping. The assembly of lithological, structural, and hydrothermal alteration data gave an idea of the mineralogy of the study area. Validity of the results was tested by comparison with the field data and the geological maps of the studied site (62% for the hydrothermal alteration zone, 81% for the lithological map, and 74% for the structural map).

The Aït Abdellah copper deposit in the Bou Azzer-El Graara inlier of the Moroccan Anti-Atlas provides key insights into structurally and lithologically controlled mineralization in Precambrian terranes. The deposit is hosted in feldspathic sandstones of the Tiddiline Group, which unconformably overlie the Bou Azzer ophiolite, and is spatially associated with a NE–SW-trending shear zone. This zone is characterized by mylonitic fabrics, calcite veining, and an extensive network of fractures, reflecting a two-stage deformation history involving early ductile shearing followed by brittle faulting and brecciation. These structural features enhanced rock permeability, enabling fluid flow and metal precipitation. Copper mineralization includes primary sulfides such as chalcopyrite, bornite, pyrite, chalcocite, digenite, and covellite, as well as supergene minerals like malachite, azurite, and chrysocolla. Sulfur isotope values (δ³⁴S = +5.9% to +22.8%) indicate a mixed sulfur source, likely derived from both ophiolitic rocks and volcano-sedimentary sequences. Carbon and oxygen isotope data suggest fluid interaction with marine carbonates and meteoric waters, potentially linked to post-Snowball Earth deglaciation processes. Fluid inclusion studies reveal homogenization temperatures ranging from 195 °C to 310 °C and salinities between 5.7 and 23.2 wt.% NaCl equivalent, supporting a model of fluid mixing between magmatic-hydrothermal and volcano-sedimentary sources. The paragenetic evolution of the deposit comprises three stages: (1) early hydrothermal precipitation of quartz, dolomite, sericite, pyrite, and early chalcopyrite and bornite; (2) a main mineralizing stage characterized by fracturing and deposition of bornite, chalcopyrite, and Ag-bearing sulfosalts; and (3) a late supergene phase with oxidation and secondary enrichment. The Aït Abdellah deposit is best classified as a shear zone-hosted copper system with a complex, multistage mineralization history. The integrated analysis of structural features, mineral assemblages, isotopic signatures, and fluid inclusion data reveals a dynamic interplay between deformation processes, hydrothermal alteration, and evolving fluid sources.

Résumé: Tamdûlt est une ville du Maroc présaharien médiéval qui était un endroit de forte activité commerciale et industrielle grâce à la richesse de son sous-sol et de sa situation sur l’une des voies commerciales reliant le Maroc avec l’Afrique sub-saharienne entre le IX^e et le XIV^e siècle. Ainsi, la frappe monétaire était l’un des piliers de son développement industriel durant l’époque médiévale. Cette ville comporte des vestiges archéologiques (scories, combustible nécessaire à la réduction du minerai, pièces de monnaie) qui ont un intérêt scientifique exceptionnel. Cependant, les recherches archéologiques menées depuis les années soixante-dix, ne présentent pas de données plus précises sur l’activité minière et métallurgique. Les vestiges de cette dernière reflètent qu’ils sont basés sur l’extraction de cuivre. Nos prospections et interprétations de terrain ont révélé l’existence de scories argentifères (en liaison avec des sites miniers d’extraction de minerais). Cette découverte apporte des données nouvelles et offrent une autre dimension au site, puisqu’en effet, l’argent serait lié à la frappe monétaire aux périodes médiévales. Ces données vont contribuer à préciser et à valoriser, d’avantage, l’histoire minière et métallurgique de cette ville et l’attribuer à son environnement minier régional.

The Aghbar deposit, located in the central part of the Bou Azzer–El Graâra inlier (Anti-Atlas, Morocco), is a cobalt-arsenic-rich mineralization system hosted mainly in Cryogenian serpentinites and their contact with overlying Ediacaran volcanic and volcano-sedimentary formations. This study...

The multispectral image, of Landsat 7 and 8; Aster and Sentinel-2A, has good results in lithological, structural, hydrothermal and mineralogical alteration mapping. Segmentation and image classification are two complementary steps as they are allowed the most important operations in the field of image processing. In this sense, this work aims at evaluating the potential of segmentation and classification algorithms for the generation of surface geological maps, hydrothermal alterations and lineaments. Given the good resolution of the Sentinel 2A (10m), the three images, (11/12; 11/2; 11/8), 12.8.2, Main Component 1,2 and 3 (11.12.2), processed by five algorithms (K-means, Isodata, watershed, efficient graph-based image segmentation, thresholding) for geological mapping and then mining exploration. The study displayed that 1) Watershed algorithm can be used for topographic and hydraulic studies, it can be very useful in the preparation phase of geological and mining infrastructures; 2) threshold segmentation does not give good results in terms of geological discrimination since it divides each image into two parts; 3) the same thing for the effective thresholding and segmentation of graph-based images; 4) The Isodata and K-means algorithms show good geological discrimination.