Syn-collisional detrital zircon source evolution in the northern Moroccan Variscides
Metadatos
Mostrar el registro completo del ítemAutor
Accotto, Cristina; Martínez Poyatos, David Jesús; Azor, Antonio; Talavera, Cristina; Evans, Noreen; Jabaloy Sánchez, Antonio; Azdimousa, Ali; Tahiri, Abdelfatah; El Hadi, HassanEditorial
Elsevier
Materia
Detrital zircon provenance Moroccan Mesetas Syn-collisional sediments Avalonian magmatic arc
Fecha
2021Referencia bibliográfica
Accotto et al. (2021) Syn-collisional detrital zircon source evolution in the northern Moroccan Variscides. Gondwana Reserarch. DOI: 10.1016/j.gr.2021.02.001
Patrocinador
Ministerio de Economía y Competitividad (MINECO) of Spain PANGEATOR (CGL2015-71692); Pre-doctoral scholarship BES-2016-078168Resumen
U–Pb dating and Hf isotopic analyses of detrital zircon grains from Cambrian-Devonian strata in the Moroccan
Mesetas were undertaken in order to constrain its Paleozoic paleogeographic evolution. In this work, we analyzed
12 LateDevonian-Late Carboniferous samples of syn-collisional detrital rocks fromtheWestern and Eastern
Moroccan Mesetas. All our samples present significant Ediacaran (ca. 620 Ma) and Rhyacian (ca. 2.1 Ga) detrital
zircon populations, suggesting that theWest African Craton remained themain source of sediments for northern
Morocco at least until the Late Carboniferous. Locally, a Stenian-Tonian (ca. 1.0 Ga) detrital zircon population is
also present, probably fed from intermittent and distant source areas located in NE Africa (e.g. Sahara
Metacraton). The collisional evolution started with the approach of an Avalonian promontory to the northern
Gondwana continental margin (latest Devonian - earliest Carboniferous), after the closure of the Rheic Ocean.
This process entailed the former subduction of the Rheic oceanic lithosphere underneath the Avalonian continental
terrane and the formation of a magmatic arc in the upper plate. In this scenario, the first syn-collisional sediments
(Tournaisian; Tiflet and Debdou-Mekkam areas) are characterized by a Devonian detrital zircon
population (ca. 370 Ma), presumably derived from the magmatic arc, and an increasing number of
Mesoproterozoic dates, putatively also sourced from the continental crust of the Avalonian terrane. After the initial
collision, only the Visean samples located in areas close to the exotic terrane (e.g. Ben Slimane area) displayed
a minor Avalonian component. Finally, the Late Carboniferous samples from the Jerada area recorded an important
Middle Carboniferous (ca. 330 Ma) detrital zircon population, probably sourced from Variscan granitoids
emplaced in the Eastern Moroccan Meseta and attesting to crustal thickening and subsequent thermal maturation
of the Gondwana continental crust in this area.