The Oumjrane-Boukerzia Mining District (Eastern Anti-Atlas, Morocco): Constraints of its geological and tectono-magmatic setting

Abstract

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.