ملخص: The petrogenesis of igneous, metamorphic and mineralized rocks in the Edough massif, NE Algeria, indicates an interplay between crustal and magmatic sources, and magmatic and surface .uids, as determined by sulphur and oxygen isotopic analyses. The Tertiary igneous rocks (microgranites and rhyolites) show a tendency towards I-type granitoids with d34S values of ?5:4  2:2‰ (1r) and d18O between ?5:6‰ and ?6:9‰, with the most hydrothermally altered rocks having the lowest d18O values. This is indicative of seawater being a major component of the hydrothermal .uids. Seawater interaction with the granitoids produced enrichment in 34S of sulphide-sulphur in both the microgranites and associated skarn mineralization. However, in the Beleleita W–Sn–(Au) deposit, magmatic .uids dominated the mineralization, re.ected by d34S values of ?1.7‰ and ?1.8‰. The basement amphibolites of Kef Lakhal indicate derivation from a basaltic magma with d18O ranging from ?4.9‰ to ?8.6‰. Locally altered amphibolite has the lowest d18O values suggestive of meteoric water interaction, whereas the highest d18O indicate the incorporation of crustal material during the genesis of the amphibolites. Crustal contamination is also re.ected in their d34S of 18‰ to ?2.1‰, with the most contaminated rocks having the lowest d34S. Host Palaeozoic mica schists with d18O of ?12.7‰ and d34S of 13.2‰ and associated marbles (d34S 9.9‰ to 17.4‰) are thought to be the most likely contaminants. At the Ain Barbar Fe–Cu–Pb–Zn deposit, d34S values range between 9.6‰ and 10.8‰, indicating that the sulphide-sulphur and base-metals were likely leached from the host Cretaceous .ysch and/or the underlying mica schists, with local Tertiary magmatic rocks providing the heat for local convection cells. At Boumaiza Fe-deposit, d34S values of the sulphide-sulphur extend from 1.2‰to 8.1‰ indicative of magmatic sulphur with the incorporation of substantial amounts of sulphur derived from the host mica schists.

لغة: إنجليزية