[We use 3D seismic data from the Lower Congo Basin to show that minibasin subsidence is largely controlled by salt weld as the associated depocentres migrate along‐ and across‐strike under thin‐skinned extension (a and b) and sedimentary loading (c). Notably, the salt weld processes formed the salt‐core structure (c) under the minibasin are protracted and diachronous, contrasting to the one‐time weld model in current literature. , Abstract Salt tectonics is an important part of the geological evolution of many continental margins, yet the four‐dimensional evolution of the minibasins, the fundamental building block of these and many other salt basins, remains poorly understood. Using high‐quality 3D seismic data from the Lower Congo Basin, offshore Angola we document the long‐term (>70 Myr) dynamics of minibasin subsidence. We show that, during the Albian, a broadly tabular layer of carbonate was deposited prior to substantial salt flow, diapirism, and minibasin formation. We identify four subsequent stages of salt‐tectonics and related minibasin evolution: (i) thin‐skinned extension (Cenomanian to Coniacian) driven by basinward tilting of the salt layer, resulting in the formation of low‐displacement normal faults and related salt rollers. During this stage, local salt welding led to the along‐strike migration of fault‐bound depocentres; (ii) salt welding below the eastern part of the minibasin (Santonian to Paleocene), causing a westward shift in depocentre location; (iii) welding below the minibasin centre (Eocene to Oligocene), resulting in the formation of a turtle and an abrupt shift of depocentres towards the flanks of the bounding salt walls; and (iv) an eastward shift in depocentre location due to regional tilting, contraction, and diapir squeezing (Miocene to Holocene). Our study shows that salt welding and subsequent contraction are key controls on minibasin geometry, subsidence and stratigraphic patterns. In particular, we show how salt welding is a protracted process, spanning > 70 Myr of the salt‐tectonic history of this, and likely other salt‐rich basins. The progressive migration of minibasin depocentres, and the associated stratigraphic architecture, record weld dynamics. Our study has implications for the tectono‐stratigraphic evolution of minibasins.]

中文翻译：

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安哥拉近海历时盐焊过程中的小型盆地沉积中心迁移

[我们使用来自下刚果盆地的 3D 地震数据表明，由于相关的沉积中心在薄皮伸展（a 和 b）和沉积载荷（c）下沿和横向迁移，小盆地的沉降在很大程度上受盐焊控制。值得注意的是，与当前文献中的一次性焊接模型形成对比的是，在小型盆地下方形成盐核结构（c）的盐焊过程是长期和历时的。, 摘要 盐构造是许多大陆边缘地质演化的重要组成部分，但小型盆地的四维演化，这些和许多其他盐盆地的基本组成部分，仍然知之甚少。使用来自安哥拉近海下刚果盆地的高质量 3D 地震数据，我们记录了小型盆地沉降的长期（> 70 Myr）动力学。我们表明，在阿尔布时期，在大量盐流、底辟作用和小型盆地形成之前，沉积了宽板状的碳酸盐层。我们确定了盐构造和相关小盆地演化的四个后续阶段：（i）由盐层向盆地倾斜驱动的薄皮伸展（森诺曼阶到科尼亚阶），导致低位移正断层和相关盐辊的形成。这一阶段，局部盐熔作用导致断层沉积中心沿走向迁移；(ii) 小盆地东部（Santonian 至古新世）下方的盐焊，导致沉积中心位置向西移动；(iii) 在小盆地中心（始新世到渐新世）下方焊接，导致海龟的形成和沉积中心向边界盐壁的侧翼突然移动；(iv) 由于区域倾斜、收缩和底辟挤压（中新世至全新世），沉积中心位置向东移动。我们的研究表明，盐熔接和随后的收缩是小型盆地几何形状、沉降和地层模式的关键控制因素。特别是，我们展示了盐焊接是一个长期的过程，跨越超过 70 Myr 的盐构造历史，可能还有其他富含盐的盆地。小型盆地沉积中心的渐进迁移以及相关的地层结构记录了焊缝动态。我们的研究对小型盆地的构造地层演化有影响。] 沉降和地层模式。特别是，我们展示了盐焊接是一个长期的过程，跨越超过 70 Myr 的盐构造历史，可能还有其他富含盐的盆地。小型盆地沉积中心的渐进迁移以及相关的地层结构记录了焊缝动态。我们的研究对小型盆地的构造地层演化有影响。] 沉降和地层模式。特别是，我们展示了盐焊接是一个长期的过程，跨越超过 70 Myr 的盐构造历史，可能还有其他富含盐的盆地。小型盆地沉积中心的渐进迁移以及相关的地层结构记录了焊缝动态。我们的研究对小型盆地的构造地层演化有影响。]