Petrogenetic and metallogenetic studies of the tertiary igneous complexes of northeast algeria

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The petro genesis of igneous, metamorphic and mineralized lithologies in the edough massif, ne algeria, indicates a clear interplay between crustal and magmatic sources, and magmatic and surface fluids, as determined by sulphur and oxygen isotopic analyses. the tertiary igneous rocks (microgranites and rhyolites) show a tendency towards i-type granitoids with 8348 values of +5.4 i 2.2%t› (lo) and 8180 varying between +5.6 and +6.9 %<›, with the most hydrothermally altered rocks having the lowest 8180 values. this is indicative of seawater being a major component of the hydrothennal fluids. seawater interaction with the granitoids produced enrichment in 348 of sulphide-sulphur in both the microgranites and associated skam mineralization. however, in the beleleita w-sn-(au) deposit, magmatic ?uids dominated the mineralization, re?ected by 8348 values of +1.7 and +l.8%t›. the basement complex amphibolites of kef lakhal indicate derivation from a basaltic magma with 8180 ranging from +49 to +8.6%t›. locally altered amphibolite has the lowest 8180 values suggestive of meteoric water interaction, whereas the highest 8180 indicate the incorporation of crustal material during the genesis of the amphibolites. cmstal contamination is also reflected in their 8348 of -18 to +2.1%t›, with the most contaminated rocks having the lowest 834