We propose a geometrically, kinematically, and mechanically viable thin-skinned kinematic forward model for a cross section intersecting the Mont Terri rock laboratory in the frontal-most part of the Jura fold-and-thrust belt, Switzerland. In addition to the available tunnel, borehole, and surface data, initial boundary conditions are crucial constraints for the forward modelling scenarios, especially the inherited topography of the basement and any pre-compressional offset within the Mesozoic sediments. Our kinematic analysis suggests an early-stage formation of the Mont Terri anticline located above ENE-trending, Late Paleozoic extensional faults, followed by back-stepping of the deformation developing the Clos du Doubs and Caquerelle anticlines further south. In this model, the thrust sequence was dictated by the inherited basement faults, which acted as nuclei for the ramps, detached along the basal décollement within the Triassic evaporites. The mechanical viability of both the thrust angles and thrust sequence was demonstrated by applying the limit analysis theory. Despite numerous subsurface geological data, extrapolation of structures to depth remains largely under-constrained. We have tested an alternative model for the same cross section, involving an upper detachment at the top of the Staffelegg Formation that leads to duplication of the sub-Opalinus Clay formations, prior to detachment and thrusting on the Triassic evaporites. This model is geometrically and kinematically viable, but raises mechanical questions. A total displacement of 2.9 and 14.2 km are inferred for the classical and the alternative scenarios, respectively. In the latter, forward modelling implies that material was transported 10.8 km along the upper detachment. It is not yet clear where this shortening might have been accommodated. Despite the differences in structural style, both models show that pre-existing basement structures might have interfered in time and space. Both styles may have played a role, with lateral variation dictated by basement inherited structures.

中文翻译：

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瑞士汝拉州西北部蒙特里（Mont Terri）岩石实验室周围的构造演化：运动学前向建模的约束

我们提出了一个几何，运动学和机械学上可行的薄皮运动学正向模型，用于与瑞士汝拉推冲带最前部的Mont Terri岩石实验室相交的横截面。除了可用的隧道，井眼和地表数据外，初始边界条件对于正演模拟场景也至关重要，特别是地下室的继承地形以及中生代沉积物中的任何预压缩偏移。我们的运动学分析表明，位于ENE趋势，晚古生代伸展断层之上的Mont Terri背斜的早期形成，然后向后退变形，进一步向南发展了Clos du Doubs和Caquerelle背斜。在这个模型中，推力序列是由继承的基底断层决定的，在三叠纪蒸发岩中沿基底裂陷分离的，作为斜坡的核。通过应用极限分析理论证明了推力角和推力序列的机械可行性。尽管有许多地下地质数据，但将结构外推到深度仍然受到很大的限制。我们已经测试了相同横截面的替代模型，其中包括在Staffelegg地层顶部的上部脱离，这导致了Opalinus黏土地层的重复，然后才将其剥离并推入三叠纪蒸发岩上。该模型在几何和运动学上都是可行的，但提出了机械问题。对于经典场景和替代场景，分别推断出总位移为2.9 km和14.2 km。在后者中，前向建模意味着材料沿上部支路运输了10.8公里。目前尚不清楚在哪里可以容纳这种起酥油。尽管结构风格有所不同，但这两个模型都表明，既有的地下室结构可能会干扰时间和空间。两种样式都可能发挥了作用，其横向变化是由地下室继承的结构决定的。