Revised stratigraphic framework for the lower Anti-Atlas Supergroup based on U–Pb geochronology of magmatic and detrital zircons (Zenaga and Bou Azzer-El Graara inliers, Anti-Atlas Belt, Morocco).
In: Journal of African Earth Sciences, Jg. 171 (2020-11-01), S. N.PAG
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Zugriff:
U–Pb geochronology of magmatic and detrital zircons (Zenaga and Bou Azzer-El Graara inliers, Anti-Atlas Belt, Morocco) and a reassessment of the published constraints suggest a revised stratigraphic framework for the lower Anti-Atlas Supergroup. Five major unconformity-bounded lithostratigraphic packages are here distinguished: the two lower units of Paleoproterozoic age are named the Tasserda-Taghatine Group (2030–1706 Ma) and the Oumoula (Mimount) Formation (ca. 1745–1650 Ma); the third unit of Paleoproterozoic to Neoproterozoic age (ca. 1650 to >883 Ma) is the Tizi n'Taghatine Group; the fourth and fifth units of Neoproterozoic age are the ca. 883 Ma Tachdamt and the ca. 700 Ma Bleida formations. Implications of this revised stratigraphic framework include: 1) the Tasserda-Taghatine Group might be linked to the post-orogenic collapse after the Eburnean Orogeny; 2) the Tizi n'Taghatine Group might be ca. 1.1 Ga in age based on proposed correlation with the Taoudeni Basin succession in Mauritania; 3) the Bleida Formation likely reflects deposition in the foreland basin at the early stage of the Pan-African Orogeny; 4) the Oumoula (Mimount) Formation, Tizi n'Taghatine Group, and Tachdamt Formation potentially record extensional events within the Nuna/Columbia and Rodinia supercontinents; 5) the provenance of the lower Anti-Atlas Supergroup (based on our new detrital zircon dating) is mainly from the West African craton along with possible contributions from other cratons such as Amazonia and the Sahara Metacraton; 6) the flood basalt sequence of the Tachdamt Formation likely belongs to the ca. 885-883 Ma intraplate Iguerda-Taïfast Large Igneous Province (LIP) event defined by previously dated dykes in the Iguerda and Taïfast inliers; and 7) the 1650 Ma Zenaga LIP can be potentially linked with LIP magmatism in Baltica and Laurentia. • The Taghdout mafic sill of the Ifzwane Suite yielded an age of 1676 ± 37 Ma. • The depositional age of the lower Anti-Atlas Supergroup ranges from 2049 to 700 Ma and the provenance is mainly from the WAC. • A new 5-part lithostratigraphic framework for the Proterozoic lower Anti-Atlas Supergroup of the Anti-Atlas Belt is proposed. • The 1650-1640 Ma Zenaga and 885-883 Ma Iguerda-Taïfast LIPs provide important stratigraphic constraints. • Correlation between the lower Anti-Atlas Supergroup and the Taoudeni Basin succession in Mauritania. [ABSTRACT FROM AUTHOR]
Titel: |
Revised stratigraphic framework for the lower Anti-Atlas Supergroup based on U–Pb geochronology of magmatic and detrital zircons (Zenaga and Bou Azzer-El Graara inliers, Anti-Atlas Belt, Morocco).
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Autor/in / Beteiligte Person: | Ait Lahna, Abdelhak ; Youbi, Nasrrddine ; Tassinari, Colombo Celso Gaeta ; Basei, Miguel Angelo Stipp ; Ernst, Richard E. ; Chaib, Latifa ; Barzouk, Abdelhafed ; Mata, João ; Gärtner, Andreas ; Admou, Hassan ; Boumehdi, Moulay Ahmed ; Söderlund, Ulf ; Bensalah, Mohamed Khalil ; Bodinier, Jean-Louis ; Maacha, Lhou ; Bekker, Andrey |
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Zeitschrift: | Journal of African Earth Sciences, Jg. 171 (2020-11-01), S. N.PAG |
Veröffentlichung: | 2020 |
Medientyp: | academicJournal |
ISSN: | 1464-343X (print) |
DOI: | 10.1016/j.jafrearsci.2020.103946 |
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