Abstract Significant, poly-phase deformation occurred prior to, simultaneous with, and after the opening of the North Atlantic Ocean. Understanding this deformation history is essential for understanding the regional development and the mechanisms controlling rifting and subsequent failure or breakup. Here, we primarily use published constraints to construct deformable plate tectonic models for the southern North Atlantic from 200 Ma to present using GPlates. The aim of this work is to test both the capability of the GPlates deformable modelling approach and the reliability of published plate reconstructions. Overall, modelled crustal thickness values at 0 Ma produced from the deformable models show general, regional-scale, similarities with values derived from the inversion of gravity data for crustal thickness. However, the deformable models typically underestimate thinning in marginal basins and overestimate crustal thickness in continental fragments compared to values from gravity inversion. This is possibly due to: 1) thinning occurring earlier than the 200 Ma start time modelled, 2) variations in the original crustal thickness, 3) depth-dependent stretching, 4) rigid blocks undergoing some degree of thinning, and 5) variations in the mesh density of the models. The results demonstrate that inclusion of micro-continental fragments, and locally defined limits of continental crust, generally produce results more akin to observations. One exception is the Grand Banks where global GPlates models produce more realistic deformation, likely due to the inclusion of the exhumed domains continent-ward of the transition zone boundary. Results also indicate that Flemish Cap rotation is required to provide a reasonable fit between North America and Iberia, with the palaeo-position of the Flemish Cap likely to be the proto-Orphan sub-basins. Moreover, the East and West Orphan sub-basins formed separately due to the respective rotations of the Flemish Cap and the Orphan Knoll, which was likely associated with other continental fragments that subsequently contributed to the thicker crust forming the boundary between the East and West Orphan basins. The results also suggest a link between tectonic and magmatic processes. For example, the inclusion of an Orphan Knoll micro-continental block results in greater extension (higher beta factors) in the northern West Orphan Basin near the termination of the Charlie-Gibbs Fracture Zone, and the site of the Charlie-Gibbs Volcanic Province (CGVP). Thus, we infer that the CGVP was likely influenced by plate tectonic processes through the concentration of strain resulting from interaction in proximity to the transform system. Finally, marginal basins that were considered to be conjugate and thus related, may only appear conjugate through later rotation of micro-continental blocks, and thus their genesis is not directly related.

中文翻译：

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北大西洋南部的变形板块构造模型

摘要 在北大西洋开放之前、同时和之后发生了显着的多相变形。了解这一变形历史对于了解区域发展和控制裂谷以及随后的破裂或破裂的机制至关重要。在这里，我们主要使用已发布的约束来构建北大西洋南部从 200 Ma 到现在使用 G Plates 的可变形板块构造模型。这项工作的目的是测试 GPlates 可变形建模方法的能力和已发布的板重建的可靠性。总体而言，由可变形模型产生的 0 Ma 模拟地壳厚度值显示出一般的、区域尺度的、与地壳厚度重力数据反演得出的值的相似性。然而，与重力反演的值相比，可变形模型通常低估边缘盆地的变薄，高估大陆碎片的地壳厚度。这可能是由于：1) 减薄发生早于模拟的 200 Ma 开始时间，2) 原始地壳厚度的变化，3) 与深度相关的拉伸，4) 刚性块体经历某种程度的减薄，以及 5)模型的网格密度。结果表明，包含微大陆碎片和局部定义的大陆地壳界限，通常会产生更类似于观测的结果。一个例外是 Grand Banks，其中全球 GPlates 模型产生了更真实的变形，这可能是由于包含了过渡区边界的已挖掘域大陆区。结果还表明，佛兰芒帽旋转需要在北美和伊比利亚之间提供合理的拟合，佛兰芒帽的古位置可能是原始孤儿子盆地。此外，由于佛兰芒帽和孤儿丘的各自旋转，东和西孤儿盆地分别形成，这可能与其他大陆碎片有关，随后导致更厚的地壳形成东和西孤儿之间的边界盆地。结果还表明构造和岩浆过程之间存在联系。例如，包含孤儿诺尔微大陆块会导致西孤儿盆地北部靠近查理-吉布斯断裂带终止处的更大扩展（更高的β系数），和查理吉布斯火山省 (CGVP) 的遗址。因此，我们推断 CGVP 很可能受到板块构造过程的影响，这是通过靠近变换系统的相互作用产生的应变集中。最后，被认为是共轭并因此相关的边缘盆地可能只有通过微大陆块的后期旋转才会出现共轭，因此它们的成因没有直接关系。