The Ediacaran volcano-sedimentary succession in the Western Skoura inlier (Central High Atlas, Morocco): facies analysis, geochemistry, geochronology and geodynamic implications
| Autor: | Karaoui A.[1, Breitkreuz C.[2], Karaoui B.[3], Yajioui Z.[1], Mahmoudi A.[1], Zanetti A.[4], Langone A.[4] |
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| Rok vydání: | 2021 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Lava Geochemistry 010502 geochemistry & geophysics 01 natural sciences Sedimentary depositional environment Volcanic rock Geochronology Rhyolite Facies General Earth and Planetary Sciences Sedimentary rock Central High Atlas Physical volcanology Ouarzazate Supergroup Peri-Gondwana terrane LA-ICPMS U-Pb dating on zircon Sedimentology Geology 0105 earth and related environmental sciences |
| Zdroj: | International journal of earth sciences (1999, Print) 110 (2021): 889–909. doi:10.1007/s00531-021-01997-y info:cnr-pdr/source/autori:Karaoui A.[1,2], Breitkreuz C.[2], Karaoui B.[3], Yajioui Z.[1], Mahmoudi A.[1], Zanetti A.[4], Langone A.[4]/titolo:The Ediacaran volcano-sedimentary succession in the Western Skoura inlier (Central High Atlas, Morocco): facies analysis, geochemistry, geochronology and geodynamic implications/doi:10.1007%2Fs00531-021-01997-y/rivista:International journal of earth sciences (1999, Print)/anno:2021/pagina_da:889/pagina_a:909/intervallo_pagine:889–909/volume:110 |
| ISSN: | 1437-3262 1437-3254 |
| DOI: | 10.1007/s00531-021-01997-y |
| Popis: | The Skoura inlier in the Moroccan High Atlas consists of thick Precambrian-Paleozoic formations. It displays, in the western part near Aguerzega village, a volcano-sedimentary succession of about 400 m thickness. It includes a variety of welded and non-welded ignimbrites, lapilli-tuff fallout deposit, coherent lava, sedimentary mass flow deposit and fluvial sediments, which are grouped into three lithofacies associations, corresponding to different depositional environments. The volcanic activity in the studied area represents successive volcanic eruptions, alternating with phases of quiescence (sedimentary beds). The Ediacaran volcano-sedimentary succession of the Skoura inlier represents an evolution in four stages in a subaerial environment. The geochemical results obtained from Skoura volcanic rocks display high silica-rich composition ranging from dacite to rhyolite. Major and trace elements show high-K calc-alkaline and alkali-calcic to alkaline affinities and reflect an active continental margin signature. In addition, the studied rocks show enriched LILE compared to HFSE with negative Nb-, Ta- and Ti anomalies. This is consistent with a post-collisional setting, documented for the final phase of the Pan-African orogeny. Laser ablation U-Pb zircon dating on three rhyolitic ignimbrites from the base and top of two profiles, yielded ages of 580 ± 7 Ma, 574 ± 14 Ma and 571 ± 4 Ma. These ages compare well with the lower Ouarzazate Supergroup, widespread in the Anti-Atlas, as well as in the High Atlas and with rare exposures in the Meseta domain in northern Morocco. |
| Databáze: | OpenAIRE |
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