Numerical modelling in 2D is used to explore interactions between synrift lithospheric extension, salt deposition and deformation, and pre- and post-salt sedimentation, for wide rifted margins with weak continental crust. Distributed aggrading synrift sedimentation enhances listric normal faulting of the sediments and crust in the mid and distal margin. In contrast, localized prograding sedimentation initiates a positive feedback between sedimentation, faulting and mid- to lower-crustal flow. This feedback causes localized crustal extension at the proximal margin, and leads to thick sediments in deep proximal basins. The feedback is more pronounced when more sediment is deposited, and does not develop in models with stronger, narrower rifted margins. Later initiation of the post-salt prograding sediments leads to a less pronounced feedback with lower-crustal flow and a more significant advancement of the prograding wedge over the salt body. We compare our model results with the rifted Nova Scotia Atlantic margin, contrasting margin evolution and salt tectonics between the northeastern region, which experienced significant post-salt synrift sedimentation, and the central region, where less post-salt sediment was deposited. We show that the northeastern margin may have experienced enhanced proximal graben development owing to prograding synrift sedimentation. Thematic collection: This article is part of the Mechanics of salt systems: state of the field in numerical methods collection available at: https://www.lyellcollection.org/cc/mechanics-of-salt-systems

中文翻译：

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宽弱大陆边缘同裂谷岩石圈伸展、沉积和盐构造之间的反馈

二维数值模拟用于探索同裂谷岩石圈伸展、盐沉积和变形以及盐前和盐后沉积之间的相互作用，适用于具有弱大陆地壳的宽裂谷边缘。分布的加积同裂谷沉积增强了中远缘沉积物和地壳的正断层作用。相比之下，局部进积沉积在沉积、断层和中下地壳流之间引发了正反馈。这种反馈导致近端边缘的局部地壳伸展，并导致近端深盆地沉积物较厚。当沉积更多沉积物时，反馈更加明显，并且不会在具有更强、更窄裂谷边缘的模型中发展。盐后进积沉积物的后期开始导致较低地壳流的反馈不那么明显，并且在盐体上的进积楔形更显着推进。我们将我们的模型结果与新斯科舍大西洋裂谷边缘比较，对比经历了显着盐后同裂谷沉积的东北地区和盐后沉积物较少的中部地区之间的对比边缘演化和盐构造。我们表明，由于前移的同裂谷沉积作用，东北边缘可能经历了近端地堑发育的增强。专题合集：本文是盐系统力学的一部分：数值方法领域的现状合集可在：https://www.lyellcollection.org/cc/mechanics-of-salt-systems 我们将我们的模型结果与新斯科舍大西洋裂谷边缘进行比较，对比经历了显着盐后同裂谷沉积的东北地区和盐后沉积物较少的中部地区之间的对比边缘演化和盐构造。我们表明，由于前移的同裂谷沉积作用，东北边缘可能经历了近端地堑发育的增强。专题合集：本文是盐系统力学的一部分：数值方法领域的现状合集可在：https://www.lyellcollection.org/cc/mechanics-of-salt-systems 我们将我们的模型结果与新斯科舍大西洋裂谷边缘比较，对比经历了显着盐后同裂谷沉积的东北地区和盐后沉积物较少的中部地区之间的对比边缘演化和盐构造。我们表明，由于前移的同裂谷沉积作用，东北边缘可能经历了近端地堑发育的增强。专题合集：本文是盐系统力学的一部分：数值方法领域的现状合集可在：https://www.lyellcollection.org/cc/mechanics-of-salt-systems 盐后沉积物沉积较少的地方。我们表明，由于前移的同裂谷沉积作用，东北边缘可能经历了近端地堑发育的增强。专题合集：本文是盐系统力学的一部分：数值方法领域的现状合集可在：https://www.lyellcollection.org/cc/mechanics-of-salt-systems 盐后沉积物沉积较少的地方。我们表明，由于前移的同裂谷沉积作用，东北边缘可能经历了近端地堑发育的增强。专题合集：本文是盐系统力学的一部分：数值方法领域的现状合集可在：https://www.lyellcollection.org/cc/mechanics-of-salt-systems