Polymetallic Mineralization in the Western Part of the Numidic Chain (North-East Algeria)

Iron and polymetallic mineralization host-rocks are located in the Tellian domain of the Maghrebides range. These host-rocks crop out as E-W oriented Jurassic complex anticlines. They are essentially composed of Liassic dolomite and limestones characterized by two types of ore deposits. Cluster iron oxides and hydroxides are associated with fissural polymetallic mineralization (Cu-Ba, Pb-Zn). Moreover, three distinctive carbonate microfacies were recognized, and they are characterized by particular components and microstructures that revealed an intertidal to infratidal depositional environment. Stable isotopes study of O and C performed on calcite gangue and micritic limestone host, which show that delta C-13(micrite) %/PDB values are between +1.02 and +2.09, while they are from -1.98 to +1.02 for delta C-13(calcite) %/PDB. This indicates an inorganic carbon source. The delta O-18(micrite)parts per thousand/PDB results are from -6.98 to -5.84 and are delta O-18(calcite)parts per thousand/PDB from -7.53 to -6.29. The delta O-18 data under -4 parts per thousand suggest that ore deposition could have been produced by mineralizing fluid with depletion in O-18 and/or with implication of hotter fluid than the host-rocks.