Abstract
AbstractThe 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.
Funder
Faculté des Sciences et de Médecine, Université de Fribourg
Publisher
Springer Science and Business Media LLC
Reference123 articles.
1. Affolter, T., & Gratier, J.-P. (2004). Map view retrodeformation of an arcuate fold-and-thrust belt: The Jura case. Journal of Geophysical Research, 109(B03404), 20. https://doi.org/10.1029/2002JB002270
2. Allenbach, R., Baumberger, R., Kurmann, E., Michael, C. S., & Reynolds, L. (2017). GeoMol: Geologisches 3D-Modell des Schweizer Molassebeckens: Schlussbericht. In Berichte der Landesgeologie (Vol. 10). Federal Office of Topography (Swisstopo).
3. Allenbach, R., & Wetzel, A. (2006). Spatial patterns of Mesozoic facies relationships and the age of the Rhenish Lineament: A compilation. International Journal of Earth Sciences, 95, 803–813. https://doi.org/10.1007/s00531-006-0071-0
4. Allmendinger, R. W. (1998). Inverse and forward numerical modeling of trishear fault-propagation folds. Tectonics, 17(4), 640–656. https://doi.org/10.1029/98TC01907
5. Antunes, V., Planès, T., Zahradník, J., Obermann, A., Alvizuri, C., Carrier, A., & Lupi, M. (2020). (2020) Seismotectonics and 1-D velocity model of the Greater Geneva Basin, France—Switzerland. Geophysical Journal International, 221(3), 2026–2047. https://doi.org/10.1093/gji/ggaa129
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献