Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling
Abstract The balancing technique, called 2D kinematic forward modelling, is a powerful tool to understand the kinematic evolution of fold-and-thrust belts. This study presents a new 2D kinematic forward model for the westernmost Internal Jura fold-and-thrust belt (FTB), situated immediately adjacent...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
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SpringerOpen
2023-07-01
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Series: | Swiss Journal of Geosciences |
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Online Access: | https://doi.org/10.1186/s00015-023-00435-2 |
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author | Adeline Marro Louis Hauvette Sandra Borderie Jon Mosar |
author_facet | Adeline Marro Louis Hauvette Sandra Borderie Jon Mosar |
author_sort | Adeline Marro |
collection | DOAJ |
description | Abstract The balancing technique, called 2D kinematic forward modelling, is a powerful tool to understand the kinematic evolution of fold-and-thrust belts. This study presents a new 2D kinematic forward model for the westernmost Internal Jura fold-and-thrust belt (FTB), situated immediately adjacent to the Geneva Basin. The technique used not only provides a new valid balanced cross-section but also offers new insights regarding the kinematic evolution of the Western Internal Jura FTB. Our model proposes a pure thin-skinned style dominated by forward stepping deformation accompanied by minor back-stepping thrust sequences. A first deformation step is attributed to the thrusting of the Crêt de la Neige Anticline, followed by the Crêt Chalam Thrust and its imbrications. This is followed by thrusting along the Tacon and the Bienne thrusts. Imbricate fault-bend folding explains the steep southern limb of the Crêt de la Neige and the Bellecombe anticlines. 2D kinematic forward modelling yields a total amount of shortening by 23.6 km for the Western Internal Jura FTB. In addition to the primary décollement located at the base of the Keuper Group evaporites, three other décollements are found within the marly layers of the Aalenian “faciès de transition” units, the Oxfordian “Couches d’Effingen-Geissberg” members and the Berriasian Goldberg formation. The multiple thrust horizon approach is supported by new precise seismic interpretations. Our model provides a valid alternative to previous models that either propose local thickening of the Triassic evaporites or inversion of normal faults in the basement. This fully explains the elevated position of the Mesozoic cover in the Jura FTB. |
first_indexed | 2024-03-12T23:21:57Z |
format | Article |
id | doaj.art-11869ea760f048dc85dd6ddc3e5b72d8 |
institution | Directory Open Access Journal |
issn | 1661-8726 1661-8734 |
language | English |
last_indexed | 2024-03-12T23:21:57Z |
publishDate | 2023-07-01 |
publisher | SpringerOpen |
record_format | Article |
series | Swiss Journal of Geosciences |
spelling | doaj.art-11869ea760f048dc85dd6ddc3e5b72d82023-07-16T11:23:31ZengSpringerOpenSwiss Journal of Geosciences1661-87261661-87342023-07-01116112910.1186/s00015-023-00435-2Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modellingAdeline Marro0Louis Hauvette1Sandra Borderie2Jon Mosar3Department of Geosciences, University of FribourgDepartment of Geosciences, University of FribourgDepartment of Geosciences, University of FribourgDepartment of Geosciences, University of FribourgAbstract The balancing technique, called 2D kinematic forward modelling, is a powerful tool to understand the kinematic evolution of fold-and-thrust belts. This study presents a new 2D kinematic forward model for the westernmost Internal Jura fold-and-thrust belt (FTB), situated immediately adjacent to the Geneva Basin. The technique used not only provides a new valid balanced cross-section but also offers new insights regarding the kinematic evolution of the Western Internal Jura FTB. Our model proposes a pure thin-skinned style dominated by forward stepping deformation accompanied by minor back-stepping thrust sequences. A first deformation step is attributed to the thrusting of the Crêt de la Neige Anticline, followed by the Crêt Chalam Thrust and its imbrications. This is followed by thrusting along the Tacon and the Bienne thrusts. Imbricate fault-bend folding explains the steep southern limb of the Crêt de la Neige and the Bellecombe anticlines. 2D kinematic forward modelling yields a total amount of shortening by 23.6 km for the Western Internal Jura FTB. In addition to the primary décollement located at the base of the Keuper Group evaporites, three other décollements are found within the marly layers of the Aalenian “faciès de transition” units, the Oxfordian “Couches d’Effingen-Geissberg” members and the Berriasian Goldberg formation. The multiple thrust horizon approach is supported by new precise seismic interpretations. Our model provides a valid alternative to previous models that either propose local thickening of the Triassic evaporites or inversion of normal faults in the basement. This fully explains the elevated position of the Mesozoic cover in the Jura FTB.https://doi.org/10.1186/s00015-023-00435-2Fold-and-thrust beltWestern Internal JuraBalanced cross-section2D kinematic forward modelKinematicsGeneva Basin |
spellingShingle | Adeline Marro Louis Hauvette Sandra Borderie Jon Mosar Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling Swiss Journal of Geosciences Fold-and-thrust belt Western Internal Jura Balanced cross-section 2D kinematic forward model Kinematics Geneva Basin |
title | Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling |
title_full | Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling |
title_fullStr | Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling |
title_full_unstemmed | Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling |
title_short | Tectonics of the Western Internal Jura fold-and-thrust belt: 2D kinematic forward modelling |
title_sort | tectonics of the western internal jura fold and thrust belt 2d kinematic forward modelling |
topic | Fold-and-thrust belt Western Internal Jura Balanced cross-section 2D kinematic forward model Kinematics Geneva Basin |
url | https://doi.org/10.1186/s00015-023-00435-2 |
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