Abstract The Maastrichtian-Danian transgression was one of the most extensive Atlantic-derived marine incursions in Patagonia. This study examines its stratigraphic record and origin in the Magallanes-Austral Basin, revealing an interplay of sedimentation, tectonism, and base-level changes, which contribute to our understanding of foreland basin dynamics. We present a multidisciplinary approach from a relatively poorly documented sector (51°38′-53°50′S) of the basin. This approach includes facies and provenance analysis, palynology, sequence stratigraphy, and U-Pb geochronology. These techniques enable us to evaluate the role of climate, tectonics, and eustasy on the transgression, as well as providing insight into the growth of the Southern Patagonian Andes. A first shallowing-upward cycle (late Campanian to late Maastrichtian) is represented by the transition from outer shelf and upper slope deposits (Fuentes and Tres Pasos formations) to shoreface and deltaic environments (Rocallosa and Dorotea formations), favoured by high erosion rates in the fold-thrust belt and eustatic sea-level drop. A subsequent deepening-upward cycle (late Maastrichtian to Paleocene) records the Atlantic transgression, manifested by estuarine deposits in an incised valley (uppermost Dorotea Formation) and deep-water turbidites (Chorrillo Chico Formation and Cabo Nariz beds). Palynological results suggest a temperate palaeoclimate (~6–17 °C) during the Maastrichtian-Danian, which agrees with significant cooling of the South Atlantic Ocean at this time. Therefore, relative climatic optima are not a driver of marine ingression. The stratigraphic and tectonic evolution of the succession studied suggests that flexural and dynamic subsidence promoted marine incursion into the Magallanes-Austral Basin. Provenance data indicate sediment input to the basin from the Southern Patagonian Batholith, Rocas Verdes Basin remnants, Tobifera Formation, and metamorphic terranes exposed in the hinterland of the Southern Patagonian Andes during the early Maastrichtian. However, by the Paleocene, sediments derived from the hinterland had been structurally dammed during basinward propagation of the fold-thrust belt.

中文翻译：

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Magallanes-Austral 前陆盆地（智利）对 Maastrichtian-Danian 海侵的构造控制：对南巴塔哥尼亚安第斯山脉生长的影响

摘要 马斯特里赫特-达尼亚海侵是巴塔哥尼亚最广泛的源自大西洋的海洋入侵之一。这项研究检查了它在麦哲伦-澳大利亚盆地的地层记录和起源，揭示了沉积作用、构造作用和基底水平变化之间的相互作用，这有助于我们了解前陆盆地动力学。我们提出了一种来自流域相对较少记录的部门（51°38'-53°50'S）的多学科方法。这种方法包括相和物源分析、孢粉学、层序地层学和 U-Pb 年代学。这些技术使我们能够评估气候、构造和 eustasy 对海侵的作用，并提供对南巴塔哥尼亚安第斯山脉生长的洞察。第一个浅层向上循环（晚坎帕阶到晚马斯特里赫特阶）表现为从外陆架和上斜坡沉积物（富恩特斯和特雷斯帕索斯地层）到滨面和三角洲环境（罗卡洛萨和多罗蒂亚地层）的过渡，受高侵蚀率的青睐褶皱逆冲带和海平面下降。随后的加深向上循环（马斯特里赫特晚期到古新世）记录了大西洋海侵，表现为下切河谷（最上部的 Dorotea 组）和深水浊积岩（Chorrillo Chico 组和 Cabo Nariz 层）中的河口沉积物。孢粉学结果表明马斯特里赫特-大年期间的温带古气候（~6-17°C）与此时南大西洋的显着冷却一致。因此，相对气候优化不是海洋入侵的驱动因素。所研究的层序的地层和构造演化表明，弯曲和动力下沉促进了海洋侵入麦哲伦盆地。物源数据表明，在马斯特里赫特早期，南巴塔哥尼亚基石、Rocas Verdes 盆地残余物、Tobifera 组和暴露在南巴塔哥尼亚安第斯山脉腹地的变质地体的沉积物输入到盆地中。然而，到了古新世，来自腹地的沉积物在褶皱冲断带向盆地的传播过程中在结构上被筑坝。在马斯特里赫特早期，南巴塔哥尼亚安第斯山脉腹地出露的 Rocas Verdes 盆地遗迹、Tobifera 组和变质地体。然而，到了古新世，来自腹地的沉积物在褶皱冲断带向盆地的传播过程中在结构上被筑坝。在马斯特里赫特早期，南巴塔哥尼亚安第斯山脉腹地出露的 Rocas Verdes 盆地遗迹、Tobifera 组和变质地体。然而，到了古新世，来自腹地的沉积物在褶皱冲断带向盆地的传播过程中在结构上被筑坝。