Les granitoides tardi-panafricains de l'Anti-Atlas sud-occidental (Maroc): Evolution d'un type magnésien à un type ferrifére. Exemple de la boutonniere d'Ifni
- Autores: A. Mortaji, D. Gasquet, M. Ikenne, E.H. Beraaouz, M. Lahmam
- Localización: Estudios geológicos, ISSN 0367-0449, Vol. 63, Nº 1, 2007, págs. 7-25
- Idioma: francés
- Títulos paralelos:
- The tardi-Pan-African granitoids of South-Westerner Anti-Atlas (Morocco): Evolution from magnesian to ferroan type. Example of the Ifni inlier
- Enlaces
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Resumen
The study of the neoproterozoic granitoids in the Ifni Inlier and those of the other inliers in south-westerner Anti-Atlas shows that this magmatism evolves from magnesian to ferroan type. In the Ifni inlier, these granitoids outcrop within the sedimentary and volcanogenic formations of the Ouarzazate Super- Group SGO (615 to 540 My). They belong to two distinct magmatic episodes (i) an early one composed of magnesian granitoids with alkali-calcic and metaluminous to slightly aluminous character (quartz bearing diorite, granodiorite and monzogranite) intrusive in the lower formations of the SGO, and (ii) a late episode associated to the summit of the SGO volcanites, which includes granites and sub-volcanic syenogranites of iron-bearing type and alkali-calcic to alkaline affinity. These magmatisms resulting from the partial melting of mixed material mark the end of the last Panafrican episode and would be set up in a transition from orogenic to anorogenic settings which announce the Paleozoic cycle. They would be contemporary to posterior with the exhumation of the extensive metamorphic domes of the Western Anti-Atlas.
