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Development and concentration of many ore deposits at the regional and district scales closely depend on structural geology, especially in polydeformed basements. The superposition of many deformation periods highlights the complexity of the structural context and expected potential location of mineralization zones. The formation and concentration of hydrothermal ore deposits is highly dependent on structural controls. On the NE flank of the Saghro massif (Eastern Anti-Atlas, Morocco), the Imiter silver mining region has been affected by multiple tectonic events since the Precambrian and throughout the Phanerozoic. In this investigation, a structural analysis of the different geological units revealed multi-stage deformation, beginning with the late Pan-African-Cadomian event, and ending with the last Cenozoic exhumation of the area. At least eight tectonic regimes have been identified. The Imiter basement, formed by the Cryogenian-early Ediacaran “flysch-like” Saghro Group, has been folded in low-grade metamorphic conditions, followed by an ENE-WSW brittle compressive event. These deformations occurred before to the early Ediacaran during the compressional and/or transpressional late Pan-African-Cadomian events (600–580 Ma). The unconformably overlaying deposition of the late Ediacaran Ouarzazate Group takes place in a WNW-ESE extensional setting and then involved in a NNW-SSE compressional event that occurred concurrently with a regional exhumation and erosion stages. A similar extensional event appears to have controlled the middle Cambrian sedimentation, the oldest Paleozoic deposits in this area. During the late Carboniferous, Variscan shortening was recorded by NW-SE transpressional deformation responsible for combined dextral strike-slip and southward thrusts. The Imiter silver mining region is part of the Moroccan Sub-Meseta Zone along with Paleozoic inliers of the Skoura and Tamlelt on the southern side of the High Atlas. The Mesozoic evolution began with the Late Triassic NNW-SSW transtensional tectonic regime with a northeast trending CAMP (Central Atlantic Magmatic Province) dyke during the Pangea breakup. Ultimately, the Imiter silver mining region experienced NNW-SSE Atlasic shortening during the uplift of the adjacent High Atlas. Over time, the direction of implemented tectonic stress and its effect on various geological units can elucidate the relationship between tectonism and hydrothermal silver mineralization in the Imiter region. In conclusion, structural analysis and investigation of paleostress development can be one of the most important factors for successful exploration plan and resource recovery in the Imiter region. An analysis of geological structures in determining feasible mineralization zones is crucial for future safe mining operation in the study area and can be extrapolated to other ore mining regions.

Purpose. The purpose of the present research is to provide a new lithological, structural and magmatic features of the Oumjrane-Boukerzia Mining District. The results obtained are used to guide exploration works for identifying the new Cu, Ni, Pb, Zn depositions and Ba-bearing mineralization within the whole Oumjrane-Boukerzia domain. Methods. This research is based on detailed mapping, structural surveys and geochemical studies performed on the magmatic rocks in the studied area. Findings. Structural and microstructural analyses of the studied area have revealed three complex polyphase tectonic events related to the Variscan orogeny: (i) an extensive phase during the Devonian period; (ii) a NW-SE compressional phase of Namuro-Westphalian age; (iii) a NE-SW compressional phase of Stephanian-Autunian age, and (iv) an extensive late phase probably related to the opening of the Central Atlantic ocean during the Late Trias-Jurassic periods. The sedimentary rocks of the district are locally intruded by small undated gabbroic intrusions. Geochemically, these gabbroic bodies are described as olivine-rich gabbros with a continental tholeiitic affinity and suggested to be related to the Central Atlantic magmatic province (CAMP) during the Pangea break-up. Originality. The present study describes the host-rocks and structural events responsible for Cu, Ni, Zn, Pb deposition and Ba-bearing mineralization in the Oumjrane-Boukerzia Mining District (Eastern Anti-Atlas, Morocco). Practical implications. The geological studies, especially lithostratigraphic, tectonic and magmatism are essential in the mineral exploration. They help exploration geologists identify and define metallotects to discover new minerals.

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