Identification, Characterization, and Deposit Model of Calcite Mineralization in the Middle Atlas Belts, Morocco

Abstract

The Middle Atlas hosts calcite veins of considerable economic value, being found in the Mahdi and Bou Naceur ridges in the eastern part of the Moroccan Middle Atlas. In this study, we aim to identify the fundamental factors controlling mineralization, which could be essential for the exploration of calcite minerals. Jurassic dolomites and limestones host calcite deposits. Mineralization is controlled by the NE-SW sinistral fault system of the Mahdi Ridge as well as by the NW-SE dextral fault system of the Bou Naceur Ridge. These veins exhibit a Riedel shear system. The edges of the veins display different textures, such as banded and brecciated calcite. At the heart of the veins are deposits of massive, automorphic, pure crystalline calcite. Geochemical analyses revealed carbonate rock dissolution and carbonate fluid infiltration, indicating the presence of a low-temperature hydrothermal system. These mineralizations are a response to the evolution of the geodynamic uplift of the Middle Atlas during the Neogene, which occurred during the Alpine orogeny.