STABLE S-, O- AND C-ISOTOPES IN THE GRANITOÏDES OF NORTHEASTERN ALGERIA: ORIGIN OF MAGMAS AND RELATED MINERALIZATION

Abstract

The structure of the North African Alpine belt is believed to be a consequence of the western Mediterranean subduction-collision of the African and European plates during the Oligo-Miocene (e.g. Auzende et al., 1975). In this geodynamic setting a number of igneous bodies were emplaced along the North African margin during the Tertiary period. The Miocene igneous rocks of NE Algeria (Fig. 1) show different emplacement styles from volcanic through subvolcanic to plutonic rocks, and diverse compositions from acidic to intermediate. These igneous rocks intruded the metamorphic basement and the overlying sedimentary formations of the Internal Zones at around 16 - 15 Ma (Bellon, 1981; Marignac and Zimmermann, 1983).