Neoproterozoic granitoids in the basement of the Moroccan Central Meseta: Correlation with the Anti-Atlas at the NW paleo-margin of Gondwana

Field observations and U-Pb LA-ICP-MS zircon ages of magmatic outcrops in the Goaïda area, south-eastern part of Moroccan Central Massif (Meseta domain), provide firm evidence of Neoproterozoic silicic magmatism in the basement of the Moroccan Variscan belt. This magmatic activity produced three distinct plutons -dark, pink and white granitoids-, which form a Neoproterozoic basement strongly reworked in the Carboniferous and intruded by Hercynian gabbro, dolerite and rhyolite bodies. The Goaïda dark granitoids are syeno-granodiorites, whereas the pink and white granitoids are granites sensu stricto. All the facies of Goaïda granitoids have I-type, high-K and calc-alkaline affinities. Concordant U-Pb zircon data yield Lowermost Ediacaran mean age for white granites (625 ± 9 Ma) and Ediacaran mean ages for dark granitoids (600 ± 10 Ma) and pink granites (552 ± 10 Ma). White granites record old high-K calc-alkaline magmatism that started in the Anti-Atlas belt at ca. 620 Ma, coinciding with the end of the second period of the Pan-African orogenesis. On the other hand, the dark and pink granitoids formed in subduction-related to post-collisional regimes during the final stage of the Pan-African orogenesis, namely the WACadomian orogeny. We combine new field, geochronological and geochemical data with results from the literature to propose a new lithostratigraphic reconstruction of the Precambrian to Early Cambrian times in the Moroccan Meseta front at the NW margin of the West African Craton. The presence of Precambrian outcrops -including Paleoproterozoic and Neoproterozoic rocks- in the Moroccan Variscan belt demonstrates the continuity of the peri-Gondwanan Panafrican basement at least from the eastern Anti-Atlas to the Central Meseta domain. Along with the lack of Paleozoic ophiolitic suture and subduction-related metamorphic rocks, this continuity supports the hypothesis that the Moroccan Variscan mountains were part of the NW margin of Gondwana in the Paleozoic.