How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts
We conducted a series of analogue experiments on shortening of a brittle cover (dry sand) above a deep, thin, frictional detachment (glass microbeads). In some experiments, the cover was homogeneous, entirely brittle. In others, there was a thin viscous silicone layer (representing salt) embedded at...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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EDP Sciences
2017-01-01
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| Series: | BSGF - Earth Sciences Bulletin |
| Subjects: | |
| Online Access: | https://www.bsgf.fr/articles/bsgf/full_html/2017/05/bsgf170007/bsgf170007.html |
| _version_ | 1818933056685211648 |
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| author | Vendeville Bruno C. Pengcheng Tang Graveleau Fabien Shaoying Huang Wang Xin |
| author_facet | Vendeville Bruno C. Pengcheng Tang Graveleau Fabien Shaoying Huang Wang Xin |
| author_sort | Vendeville Bruno C. |
| collection | DOAJ |
| description | We conducted a series of analogue experiments on shortening of a brittle cover (dry sand) above a deep, thin, frictional detachment (glass microbeads). In some experiments, the cover was homogeneous, entirely brittle. In others, there was a thin viscous silicone layer (representing salt) embedded at mid height into the cover, and initially located in the foreland of the fold-and-thrust belt. Our goal was to determine whether or not the presence of such a décollement in the cover could have an impact on the mechanics and kinematics of the underlying subsalt thrusts. Results confirm that, once the front of the foldbelt reached the hinterland salt pinch out, the kinematics of the deeper belt changed drastically: its front stopped propagating forward, and most of the subsequent shortening was accommodated by a larger-than-normal slip along the foremost and youngest deep thrust, while, above the salt décollement, the deformation front propagated very fast, creating a very low surface slope. We hypothesize that it is the gentle sub-critical surface slope associated with rocksalt’s low viscosity that prevents the build-up of an overall surface slope steep enough to allow the underlying, deep foldbelt to continue propagating forward. Finally, one experiment in which only one half of the width of the model comprised an interbedded viscous décollement has shown that the kinematics of the deep thrust was affected even in the adjacent salt-free domain. |
| first_indexed | 2024-12-20T04:42:19Z |
| format | Article |
| id | doaj.art-2823c701d9754e3baace2c1f3df6ae9d |
| institution | Directory Open Access Journal |
| issn | 0037-9409 1777-5817 |
| language | English |
| last_indexed | 2024-12-20T04:42:19Z |
| publishDate | 2017-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | BSGF - Earth Sciences Bulletin |
| spelling | doaj.art-2823c701d9754e3baace2c1f3df6ae9d2022-12-21T19:53:05ZengEDP SciencesBSGF - Earth Sciences Bulletin0037-94091777-58172017-01-0118863710.1051/bsgf/2017202bsgf170007How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust beltsVendeville Bruno C.Pengcheng TangGraveleau FabienShaoying HuangWang XinWe conducted a series of analogue experiments on shortening of a brittle cover (dry sand) above a deep, thin, frictional detachment (glass microbeads). In some experiments, the cover was homogeneous, entirely brittle. In others, there was a thin viscous silicone layer (representing salt) embedded at mid height into the cover, and initially located in the foreland of the fold-and-thrust belt. Our goal was to determine whether or not the presence of such a décollement in the cover could have an impact on the mechanics and kinematics of the underlying subsalt thrusts. Results confirm that, once the front of the foldbelt reached the hinterland salt pinch out, the kinematics of the deeper belt changed drastically: its front stopped propagating forward, and most of the subsequent shortening was accommodated by a larger-than-normal slip along the foremost and youngest deep thrust, while, above the salt décollement, the deformation front propagated very fast, creating a very low surface slope. We hypothesize that it is the gentle sub-critical surface slope associated with rocksalt’s low viscosity that prevents the build-up of an overall surface slope steep enough to allow the underlying, deep foldbelt to continue propagating forward. Finally, one experiment in which only one half of the width of the model comprised an interbedded viscous décollement has shown that the kinematics of the deep thrust was affected even in the adjacent salt-free domain.https://www.bsgf.fr/articles/bsgf/full_html/2017/05/bsgf170007/bsgf170007.htmlsalt tectonicsfold-and-thrust beltsanalogue modelingdécollement |
| spellingShingle | Vendeville Bruno C. Pengcheng Tang Graveleau Fabien Shaoying Huang Wang Xin How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts BSGF - Earth Sciences Bulletin salt tectonics fold-and-thrust belts analogue modeling décollement |
| title | How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts |
| title_full | How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts |
| title_fullStr | How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts |
| title_full_unstemmed | How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts |
| title_short | How the presence of a salt décollement in the sedimentary cover influences the behavior of subsalt thrusts in fold-and-thrust belts |
| title_sort | how the presence of a salt decollement in the sedimentary cover influences the behavior of subsalt thrusts in fold and thrust belts |
| topic | salt tectonics fold-and-thrust belts analogue modeling décollement |
| url | https://www.bsgf.fr/articles/bsgf/full_html/2017/05/bsgf170007/bsgf170007.html |
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