Recycling of the Proterozoic crystalline basement in the Coastal Block (Moroccan Meseta): New insights for understanding the geodynamic evolution of the northern peri-Gondwanan realm
| Autor: | Ahmed El Attari, Cristina Gama, J. B. Silva, Nasser Ennih, Abdellatif Jouhari, Mohamed El Houicha, Manuel Francisco Pereira, Hassan Ezzouhairi, Abdelilah Fekkak |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Provenance
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Proterozoic Geochemistry North-Gondwana Geology Detrital zircon age spectra Cadomian/Pan-African 010502 geochemistry & geophysics 01 natural sciences Eburnian Moroccan Meseta Igneous rock Craton Basement (geology) Geochemistry and Petrology Rhyolite Siliciclastic 0105 earth and related environmental sciences Zircon |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação instacron:RCAAP |
| Popis: | Detrital zircon age spectra from the siliciclastic rocks of the Lalla Mouchaa Calcschists and El Jadida Dolomitic formations (the Coastal Block of the Moroccan Meseta) are dominated by Paleoproterozoic and Ediacaran ages. The provenance of these two formations is a composite Proterozoic crystalline basement. El Jadida rhyolite (584.2 ± 4.8 Ma) represents the Ediacaran crystalline basement of the El Jadida dome. El Jadida rhyolite is unconformably overlain by the microbreccia, arkosic sandstone and dolostone of the El Jadida Dolomitic Formation with a maximum depositional age of ca. 539 Ma (Lower Cambrian). Detrital zircon-age spectra from El Jadida Dolomitic Formation (ca. 583–582 Ma) suggest direct recycling of El Jadida rhyolite as an exclusive original primary source. However, in the Western Rehamna massif, detrital zircon-age spectra from pre-Middle Cambrian microbreccia and arkosic sandstone of the Lalla Mouchaa Calcschists Formation (ca. 2.05–2.03 Ga) indicate exclusive recycling of the ca. 2.05 Ga-aged crystalline basement rocks (original primary source). Detrital zircon contents of the siliciciclastic rocks from these two formations of the Coastal Block are consistent with derivation from either Eburnian (Paleoproterozoic) or Cadomian/Pan-African (Ediacaran) igneous rocks. The discovery of this composite Proterozoic crystalline basement in the Moroccan Meseta stresses that Cadomian/Pan-African magmatic arcs were built on an Eburnian basement in a paleoposition close to the West African craton, as part of the northern peri-Gondwanan realm. |
| Databáze: | OpenAIRE |
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