Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case
Sedimentary breccias deposited on a talus slope during extension at the front of a normal fault or at the base of a slope are related to the creation of substantial topography. The architecture of talus slopes resulting from exhumation during extension is different from that of rock cliffs without d...
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| Format: | Article |
| Language: | English |
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Académie des sciences
2022-12-01
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| Series: | Comptes Rendus. Géoscience |
| Subjects: | |
| Online Access: | https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.5802/crgeos.177/ |
| _version_ | 1797651339170283520 |
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| author | Nalpas, Thierry Kernif, Tarik Bassandi, Jean Nick Kermarrec, Jean-Jacques |
| author_facet | Nalpas, Thierry Kernif, Tarik Bassandi, Jean Nick Kermarrec, Jean-Jacques |
| author_sort | Nalpas, Thierry |
| collection | DOAJ |
| description | Sedimentary breccias deposited on a talus slope during extension at the front of a normal fault or at the base of a slope are related to the creation of substantial topography. The architecture of talus slopes resulting from exhumation during extension is different from that of rock cliffs without deformation. In this work, we run several analogue models, with or without extension, in order to analyse the external geometry and internal organization of sedimentary breccias and their evolution in time and space. This temporal organization of the sand layers in the experiments shows that normal unroofing sequences are characteristic of progressive exhumation and continuous deformation during extension, whereas reverse unroofing is related to cliff destruction without vertical movement. In the experiment with wet layers of sand, the blocks that resulted from the aggregates of sand grains are generally deposited farther away than single sand grains and are located at the base of the slope; this is one of the main characteristics of rockfalls. The analogue results are compared to natural examples. |
| first_indexed | 2024-03-11T16:14:34Z |
| format | Article |
| id | doaj.art-c09ac876a6b8439fb97734bcf9147070 |
| institution | Directory Open Access Journal |
| issn | 1778-7025 |
| language | English |
| last_indexed | 2024-03-11T16:14:34Z |
| publishDate | 2022-12-01 |
| publisher | Académie des sciences |
| record_format | Article |
| series | Comptes Rendus. Géoscience |
| spelling | doaj.art-c09ac876a6b8439fb97734bcf91470702023-10-24T14:24:00ZengAcadémie des sciencesComptes Rendus. Géoscience1778-70252022-12-01354G233934910.5802/crgeos.17710.5802/crgeos.177Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural caseNalpas, Thierry0https://orcid.org/0000-0002-4318-1193Kernif, Tarik1https://orcid.org/0000-0002-5785-3296Bassandi, Jean Nick2Kermarrec, Jean-Jacques3Univ. Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, FranceUniv. Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, FranceUniv. Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, FranceUniv. Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, FranceSedimentary breccias deposited on a talus slope during extension at the front of a normal fault or at the base of a slope are related to the creation of substantial topography. The architecture of talus slopes resulting from exhumation during extension is different from that of rock cliffs without deformation. In this work, we run several analogue models, with or without extension, in order to analyse the external geometry and internal organization of sedimentary breccias and their evolution in time and space. This temporal organization of the sand layers in the experiments shows that normal unroofing sequences are characteristic of progressive exhumation and continuous deformation during extension, whereas reverse unroofing is related to cliff destruction without vertical movement. In the experiment with wet layers of sand, the blocks that resulted from the aggregates of sand grains are generally deposited farther away than single sand grains and are located at the base of the slope; this is one of the main characteristics of rockfalls. The analogue results are compared to natural examples.https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.5802/crgeos.177/Analogue modellingNormal faultSedimentary brecciasNormal/reverse unroofing sequenceTalus fanAnalogue modelling |
| spellingShingle | Nalpas, Thierry Kernif, Tarik Bassandi, Jean Nick Kermarrec, Jean-Jacques Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case Comptes Rendus. Géoscience Analogue modelling Normal fault Sedimentary breccias Normal/reverse unroofing sequence Talus fan Analogue modelling |
| title | Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case |
| title_full | Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case |
| title_fullStr | Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case |
| title_full_unstemmed | Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case |
| title_short | Analogue modelling of sedimentary breccias in a talus slope with or without extension—comparison with a natural case |
| title_sort | analogue modelling of sedimentary breccias in a talus slope with or without extension comparison with a natural case |
| topic | Analogue modelling Normal fault Sedimentary breccias Normal/reverse unroofing sequence Talus fan Analogue modelling |
| url | https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.5802/crgeos.177/ |
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