Geological features of the Zn-Pb prospect in the Bou-Izourane district (Morocco)

Abstract

The Zn-Pb mineralization in the Bou-Izourane district, located in the High Atlas Mountains of Morocco, contains estimated reserves of 40 200 tons of ore with an average grade of 20% Zn and 3.5% Pb. It is developed on N–S to NNW–SSE-trending faults that cut Liassic carbonate marl deposits. The paragenetic mineral sequence consists of galena, sphalerite and late-stage calcite. Oxidation phases of galena into cerussite and sphalerite into smithsonite are common in the Bou-Izourane ore, linked to the infiltration of meteoric waters and the oxidation of these sulphides. The Zn-Pb mineralization runs parallel to the fluorite veins associated with the igneous rocks of Tamazeght, but no petrographic or field relationship has been demonstrated between these two mineralizations (i.e., Zn-Pb and fluorite). The distribution of rare earth elements and yttrium (REY) in the Zn-Pb mineralization of Bou-Izourane shows a notable similarity with the Mississippi Valley Type (MVT) mineralization of the Central High Atlas of Morocco, although the concentrations more closely resemble those of REY in fluorite linked to the magmatic-hydrothermal activity of Tamazeght. However, the analysis of their distribution in post-fluorite calcite and post-Zn-Pb calcite reveals a strong concordance, suggesting that these two calcites are associated with the same phase and have a common origin. The classification of the Zn-Pb prospect in Bou-Izourane remains controversial, fluctuating between an MVT-type mineralization, similar to most Zn-Pb mineralizations in the Central High Atlas of Morocco, and a mineralization linked to the magmatic-hydrothermal activity of Tamazeght, which could provide heat and metallogenic material. Characterizing the Zn-Pb ore of Bou-Izourane is crucial for the future exploration of zinc and lead deposits in the High Atlas of Morocco and could advance the development of Zn-Pb mining in the region, from artisanal exploitation to professional mining