Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees
Breccias associated with tectonic, fluid and sedimentary evolution of rifted margins can provide information on a variety of processes reflecting the modes of extension. In this paper, we analyse the numerous breccias exposed in the Agly Massif that was part of the European side of the Cretaceous ri...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2022-01-01
|
| Series: | BSGF - Earth Sciences Bulletin |
| Subjects: | |
| Online Access: | https://www.bsgf.fr/articles/bsgf/full_html/2022/01/bsgf210049/bsgf210049.html |
| _version_ | 1811179671928176640 |
|---|---|
| author | Motus Martin Nardin Elise Mouthereau Frédéric Denèle Yoann |
| author_facet | Motus Martin Nardin Elise Mouthereau Frédéric Denèle Yoann |
| author_sort | Motus Martin |
| collection | DOAJ |
| description | Breccias associated with tectonic, fluid and sedimentary evolution of rifted margins can provide information on a variety of processes reflecting the modes of extension. In this paper, we analyse the numerous breccias exposed in the Agly Massif that was part of the European side of the Cretaceous rift now inverted in the eastern Pyrenees. Using a combination of petrologic and sedimentologic analyses, field-based structural study, and multivariate analysis of clast shape and diversity, binding lithology and size, and breccia fabrics, we distinguish 5 types of breccias reflecting depositional, tectonic, and salt-related processes. The integration of these processes in the tectonic history of the eastern Pyrenees confirms the attribution of these breccias to the Cretaceous rifting. We emphasize the major role played by the evaporitic Triassic particularly during the first stages of rifting as a major decoupling level at the basement/cover interface. Salt tectonics and shearing assisted by the circulation of fluids are reflected by hydrofracturing at the base of the Mesozoic cover. As this weak mechanical layer is later extracted as extension increases, a brittle detachment system developed along the cover-basement interface to exhume of deep crust and mantle. The relationships between brecciation and Cretaceous extension in the Pyrenees argue for a mixed mode of rifting associated with ductile and brittle deformation during the formation of the hyper-extended rift domain. |
| first_indexed | 2024-04-11T06:37:28Z |
| format | Article |
| id | doaj.art-cf5c8166ffc8457a85ced049c9618ed7 |
| institution | Directory Open Access Journal |
| issn | 1777-5817 |
| language | English |
| last_indexed | 2024-04-11T06:37:28Z |
| publishDate | 2022-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | BSGF - Earth Sciences Bulletin |
| spelling | doaj.art-cf5c8166ffc8457a85ced049c9618ed72022-12-22T04:39:39ZengEDP SciencesBSGF - Earth Sciences Bulletin1777-58172022-01-011931410.1051/bsgf/2022013bsgf210049Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern PyreneesMotus Martin0Nardin Elise1Mouthereau Frédéric2https://orcid.org/0000-0001-7073-4905Denèle Yoann3https://orcid.org/0000-0003-1307-6330Géosciences Environnement Toulouse, Université de Toulouse, CNRS, IRD, UPS, CNESGéosciences Environnement Toulouse, Université de Toulouse, CNRS, IRD, UPS, CNESGéosciences Environnement Toulouse, Université de Toulouse, CNRS, IRD, UPS, CNESGéosciences Environnement Toulouse, Université de Toulouse, CNRS, IRD, UPS, CNESBreccias associated with tectonic, fluid and sedimentary evolution of rifted margins can provide information on a variety of processes reflecting the modes of extension. In this paper, we analyse the numerous breccias exposed in the Agly Massif that was part of the European side of the Cretaceous rift now inverted in the eastern Pyrenees. Using a combination of petrologic and sedimentologic analyses, field-based structural study, and multivariate analysis of clast shape and diversity, binding lithology and size, and breccia fabrics, we distinguish 5 types of breccias reflecting depositional, tectonic, and salt-related processes. The integration of these processes in the tectonic history of the eastern Pyrenees confirms the attribution of these breccias to the Cretaceous rifting. We emphasize the major role played by the evaporitic Triassic particularly during the first stages of rifting as a major decoupling level at the basement/cover interface. Salt tectonics and shearing assisted by the circulation of fluids are reflected by hydrofracturing at the base of the Mesozoic cover. As this weak mechanical layer is later extracted as extension increases, a brittle detachment system developed along the cover-basement interface to exhume of deep crust and mantle. The relationships between brecciation and Cretaceous extension in the Pyrenees argue for a mixed mode of rifting associated with ductile and brittle deformation during the formation of the hyper-extended rift domain.https://www.bsgf.fr/articles/bsgf/full_html/2022/01/bsgf210049/bsgf210049.htmlriftingpyreneesbrecciasalt-tectonicsuncouplingdetachment |
| spellingShingle | Motus Martin Nardin Elise Mouthereau Frédéric Denèle Yoann Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees BSGF - Earth Sciences Bulletin rifting pyrenees breccia salt-tectonics uncoupling detachment |
| title | Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees |
| title_full | Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees |
| title_fullStr | Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees |
| title_full_unstemmed | Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees |
| title_short | Evolution of rift-related cover-basement decoupling revealed by brecciation processes in the eastern Pyrenees |
| title_sort | evolution of rift related cover basement decoupling revealed by brecciation processes in the eastern pyrenees |
| topic | rifting pyrenees breccia salt-tectonics uncoupling detachment |
| url | https://www.bsgf.fr/articles/bsgf/full_html/2022/01/bsgf210049/bsgf210049.html |
| work_keys_str_mv | AT motusmartin evolutionofriftrelatedcoverbasementdecouplingrevealedbybrecciationprocessesintheeasternpyrenees AT nardinelise evolutionofriftrelatedcoverbasementdecouplingrevealedbybrecciationprocessesintheeasternpyrenees AT mouthereaufrederic evolutionofriftrelatedcoverbasementdecouplingrevealedbybrecciationprocessesintheeasternpyrenees AT deneleyoann evolutionofriftrelatedcoverbasementdecouplingrevealedbybrecciationprocessesintheeasternpyrenees |