U–Pb geochronology of Variscan granitoids from the Moroccan Meseta (Northwest Africa): Tectonic implications

Geological and Geochemical Characterization of Variscan Pegmatites in the Sidi Bou Othmane District, Central Jebilet Province, Morocco

“…Chopin et al [35] propose two discernible magmatic pulses during the early Carboniferous and late Carboniferous to early Permian periods across the entire Meseta domain, refuting the previous notion of three distinct pulses. The U-Pb method gave ages of 350-330 Ma to the initial magmatic activity, coinciding with the Eovariscan phase and the formation of intracontinental basins throughout the Meseta.…”

“…The late Carboniferous event follows the closure of the Rheic Ocean, and the magmatic activity coincides with syn-compressional deformation in neighboring regions, such as Iberia and Central Massif. This late Carboniferous event is followed by an early Permian collision between Gondwana and Laurussia, leading to enhanced late/post-orogenic magmatism in the Meseta region [35][36][37].…”

Geochemistry, Rb-Sr whole rock age and Sr-Nd isotopic constraints on the Variscan A1-type granite from Azegour area in the Marrakech High Atlas (Moroccan Meseta) and their geodynamic implications

“…Granitoids are major components of the continental crust. Their study has led to understanding the conditions of emplacement of intrusion rocks in their deformed Variscan basement (e.g., Lagarde & Choukroune, 1982;Vigneresse, 1995;Essaifi et al, 2001;Lécuyer et al, 2017;Delchini et al, 2018;Chopin et al, 2023). Although the generation of granitic magmas can take place in almost all geotectonic environments (e.g., White & Chappell, 1983;Pearce et al, 1984;Whalen, 1985;Maniar & Piccoli, 1989;Eby, 1992;Moyen et al, 2017;Castro, 2021), the intrusion of large volumes of granitic rocks is preferably associated with areas where the continental crust had been thickened as a consequence of collisional mountain building, such as ocean-continent or continent-continent convergence.…”

“…The genesis of these granitoids may be related to either the interaction of mantellic magma with crustal rocks or with the partial fusion of exclusively crustal sources. The present-day structure of the Moroccan Variscan belt is mainly the result of oblique convergence between the Gondwana and the Laurasia supercontinents during the late Palaeozoic (e.g., Ribeiro et al, 1979;Matte, 2001;Michard et al, 2010;Martínez-Catalán et al, 2021;Arenas et al, 2021;Chopin et al, 2023). This chain, located in northwest African Variscan-Alleghanian orogen, is subdivided into different segments (Fig.…”

“…Whole-rock radiometric ages available for the Variscan granites in the Western Meseta (Fig. 1) range between 330 and 260 Ma (e.g., Mrini et al, 1992;Gasquet et al, 1996;Essaifi et al, 2003;Marcoux et al, 2019;Chopin et al 2023).…”