Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism
Abstract A striking feature of the Imilchil alkaline province, in the Moroccan Central High Atlas, is the close association of magmatic intrusions with Triassic sediments exhumed by diapirism. This study reports field, petrographic, geochemical and Sr‐Nd isotopic data, as well as new U‐Pb zircon age...
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| Language: | English |
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Wiley
2025-06-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Online Access: | https://doi.org/10.1029/2025GC012178 |
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| author | Youssef Ahechach Muhammad Ouabid Françoise Roger Fleurice Parat Otmane Raji Jean‐Marie Dautria Valérie Bosse Cheikh Elwali Malainine Hicham El Messbahi Hamza Skikra Jean‐Louis Bodinier |
| author_facet | Youssef Ahechach Muhammad Ouabid Françoise Roger Fleurice Parat Otmane Raji Jean‐Marie Dautria Valérie Bosse Cheikh Elwali Malainine Hicham El Messbahi Hamza Skikra Jean‐Louis Bodinier |
| author_sort | Youssef Ahechach |
| collection | DOAJ |
| description | Abstract A striking feature of the Imilchil alkaline province, in the Moroccan Central High Atlas, is the close association of magmatic intrusions with Triassic sediments exhumed by diapirism. This study reports field, petrographic, geochemical and Sr‐Nd isotopic data, as well as new U‐Pb zircon ages, which allow us to constrain the timing of the intrusions and to discuss their relationship to diapiric structures and the magmatic and hydrothermal processes. Our results indicate a restricted range of Late Jurassic ages (ca. 163 ± 1—ca. 149 ± 2 Ma) for the paroxysm of magmatic activity and confirm the diachronicity between diapirism and magmatism, albeit with a short interval of only a few My between the end of diapirism and the magmatic paroxysm. Deep‐seated faults associated with transtensional tectonics, accommodating the increasing spreading rate of the Central Atlantic during the Jurassic, played a key role in the close association of magmatic intrusions with diapirs. The faults first triggered active diapirism in the Early‐ Jurassic and then guided OIB‐type partial melts formed by local decompression melting of the mantle. At shallower depths, the diapiric structures acted as corridors for magma migration, probably using evaporites as preferential pathways. Magmas underwent fractional crystallization and interacted with evaporites to produce pervasive Na‐rich hydrothermal fluids. |
| format | Article |
| id | doaj-art-45d57fae22e4426287c7ed2d3111d346 |
| institution | Kabale University |
| issn | 1525-2027 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj-art-45d57fae22e4426287c7ed2d3111d3462025-08-20T03:30:36ZengWileyGeochemistry, Geophysics, Geosystems1525-20272025-06-01266n/an/a10.1029/2025GC012178Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt DiapirismYoussef Ahechach0Muhammad Ouabid1Françoise Roger2Fleurice Parat3Otmane Raji4Jean‐Marie Dautria5Valérie Bosse6Cheikh Elwali Malainine7Hicham El Messbahi8Hamza Skikra9Jean‐Louis Bodinier10Geology & Sustainable Mining Institute (GSMI) University Mohammed VI Polytechnic (UM6P) Benguerir MoroccoGeology & Sustainable Mining Institute (GSMI) University Mohammed VI Polytechnic (UM6P) Benguerir MoroccoGéosciences Montpellier Université de Montpellier & CNRS Montpellier FranceGéosciences Montpellier Université de Montpellier & CNRS Montpellier FranceGeology & Sustainable Mining Institute (GSMI) University Mohammed VI Polytechnic (UM6P) Benguerir MoroccoGéosciences Montpellier Université de Montpellier & CNRS Montpellier FranceLaboratoire Magmas et Volcans Université Clermont Auvergne Campus Universitaire des Cézeaux Clermont‐Ferrand FranceGeology & Sustainable Mining Institute (GSMI) University Mohammed VI Polytechnic (UM6P) Benguerir MoroccoDepartment of Geology Polydisciplinary Faculty Sidi Mohamed Ben Abdallah University Taza MoroccoGeology & Sustainable Mining Institute (GSMI) University Mohammed VI Polytechnic (UM6P) Benguerir MoroccoInstitute for Advanced Studies University Mohammed VI Polytechnic (UM6P) Benguerir MoroccoAbstract A striking feature of the Imilchil alkaline province, in the Moroccan Central High Atlas, is the close association of magmatic intrusions with Triassic sediments exhumed by diapirism. This study reports field, petrographic, geochemical and Sr‐Nd isotopic data, as well as new U‐Pb zircon ages, which allow us to constrain the timing of the intrusions and to discuss their relationship to diapiric structures and the magmatic and hydrothermal processes. Our results indicate a restricted range of Late Jurassic ages (ca. 163 ± 1—ca. 149 ± 2 Ma) for the paroxysm of magmatic activity and confirm the diachronicity between diapirism and magmatism, albeit with a short interval of only a few My between the end of diapirism and the magmatic paroxysm. Deep‐seated faults associated with transtensional tectonics, accommodating the increasing spreading rate of the Central Atlantic during the Jurassic, played a key role in the close association of magmatic intrusions with diapirs. The faults first triggered active diapirism in the Early‐ Jurassic and then guided OIB‐type partial melts formed by local decompression melting of the mantle. At shallower depths, the diapiric structures acted as corridors for magma migration, probably using evaporites as preferential pathways. Magmas underwent fractional crystallization and interacted with evaporites to produce pervasive Na‐rich hydrothermal fluids.https://doi.org/10.1029/2025GC012178 |
| spellingShingle | Youssef Ahechach Muhammad Ouabid Françoise Roger Fleurice Parat Otmane Raji Jean‐Marie Dautria Valérie Bosse Cheikh Elwali Malainine Hicham El Messbahi Hamza Skikra Jean‐Louis Bodinier Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism Geochemistry, Geophysics, Geosystems |
| title | Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism |
| title_full | Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism |
| title_fullStr | Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism |
| title_full_unstemmed | Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism |
| title_short | Petrochronology of Alkaline Intrusive Magmatism in the Central High‐Atlas (Morocco) and Relationships With Jurassic Salt Diapirism |
| title_sort | petrochronology of alkaline intrusive magmatism in the central high atlas morocco and relationships with jurassic salt diapirism |
| url | https://doi.org/10.1029/2025GC012178 |
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