Data_Sheet_1_Stretching and Contraction of Extensional Basins With Pre-Rift Salt: A Numerical Modeling Approach.docx

We present a series of 2D thermo-mechanical numerical experiments of thick-skinned crustal extension including a pre-rift salt horizon and subsequent thin-, thick-skinned, or mixed styles of convergence accompanied by surface processes. Extension localization along steep basement faults produces half-graben structures and leads to variations in the original distribution of pre-rift salt. Thick-skinned extension rate and salt rheology control hanging wall accommodation space as well as the locus and timing of minibasin grounding. Upon shortening, extension-related basement steps hinder forward propagation of evolving shallow thrust systems; conversely, if full basin inversion takes place along every individual fault, the regional salt layer is placed back to its pre-extensional configuration, constituting a regionally continuous décollement. Continued shortening and basement involvement deform the shallow fold-thrust structures and locally breaches the shallow décollement. We aim at obtaining a series of structural, stratigraphic and kinematic templates of fold-and-thrust belts involving rift basins with an intervening pre-rift salt horizon. Numerical results are compared to natural cases of salt-related inversion tectonics to better understand their structural evolution.

本报告呈现了一系列针对厚皮地壳伸展的二维热-力学数值实验，其中包含裂谷前盐层以及随后的薄皮、厚皮或混合收敛样式，伴随地表过程。沿陡峭的基底断层伸展定位产生半地堑结构，导致裂谷前盐的原初分布发生变异。厚皮地壳伸展速率和盐的流变学特性控制着悬壁的容纳空间，以及微盆地的沉降位置和时机。在缩短过程中，与伸展相关的基底阶地阻碍了演化的浅层逆冲系统的向前传播；反之，如果每个断层都发生全盆地的反转，则区域性的盐层将恢复到其伸展前的配置，构成一个区域连续的滑脱层。持续的缩短和基底卷入导致浅层褶皱逆冲结构变形，并局部突破浅层滑脱层。本研究旨在获得一系列涉及裂谷盆地和介于其间的裂谷前盐层的褶皱逆冲带的构造、地层学和运动学模板。数值结果与盐相关逆构造学的自然案例进行比较，以更好地理解其结构演化。