Widespread flooding of the Australian continent during the Early Cretaceous, referred to as the Eromanga Sea, deposited extensive shallow marine sediments throughout the Great Artesian Basin (GAB). This event had been considered ‘out of sync’ with eustatic sea level and was instead solely attributed to dynamic subsidence associated with Australia's passage over eastern Gondwanan subducted material. However, mantle convection models previously used to explain this event have since been shown to overestimate dynamic topography amplitude by a factor of two compared with residual topography estimates. Previous models were also based on a Cretaceous eustatic sea level peak at ca. 90 Ma in conventional eustatic sea level curves; however, more recent estimates of global sea level from ocean basin volume (OBV) suggest this peak may have occurred earlier at ca. 120 Ma. Our work links time-dependent erosion and deposition with dynamic topography and eustasy to test their contribution to basin development using the landscape evolution code pyBadlands. Our results show that the lower amplitude estimates of dynamic topography derived from pseudo-compressible mantle flow models better reflect the Cretaceous vertical motions of the Australian continent (ca. 100 m) compared with their incompressible counterparts (ca. 200–400 m). Additionally, our models include the Neogene north-eastward tilting of Australia, elusive in most previously published geodynamic models. In conjunction with an OBV-derived sea level curve, our preferred landscape evolution model broadly matches the Cretaceous inundation patterns and first-order sedimentary sequences in the GAB. The results highlight that the Early Cretaceous inundation of the Australian continent is likely a combination of high global sea levels and the regional effects of dynamic subsidence. Our work provides a framework for a new generation of evolving paleogeographic models at continental scales, while also providing key insights into the viability of existing sea level curves and dynamic topography estimates for reproducing topographic and basin evolution.

中文翻译：

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模拟动态地形和eustasy在大自流盆地演化中的作用

早白垩世澳大利亚大陆的大面积洪水，称为埃罗曼加海，在整个大自流盆地 (GAB) 沉积了广泛的浅海沉积物。该事件被认为与海平面“不同步”，而是完全归因于与澳大利亚通过东部冈瓦纳俯冲物质相关的动态下沉。然而，先前用于解释这一事件的地幔对流模型已被证明与残余地形估计值相比，高估了动态地形振幅的两倍。以前的模型也基于约 10 米的白垩纪海平面峰值。90 Ma 在传统的静海平面曲线中；然而，最近根据海洋盆地体积 (OBV) 对全球海平面的估计表明，这个峰值可能更早发生在约 120 马。我们的工作将随时间变化的侵蚀和沉积与动态地形和 eustasy 联系起来，以使用景观演化代码 pyBadlands 测试它们对盆地发展的贡献。我们的结果表明，与不可压缩的对应物（约 200-400 m）相比，来自拟可压缩地幔流模型的动态地形的较低振幅估计更好地反映了澳大利亚大陆（约 100 m）的白垩纪垂直运动。此外，我们的模型包括澳大利亚的新近纪东北倾斜，这在大多数以前发表的地球动力学模型中难以捉摸。结合 OBV 导出的海平面曲线，我们首选的景观演化模型与 GAB 中的白垩纪淹没模式和一级沉积层序大致相符。结果强调，澳大利亚大陆的早白垩世淹没可能是全球海平面高和动态沉降的区域影响的结合。我们的工作为大陆尺度上新一代演化的古地理模型提供了一个框架，同时还提供了对现有海平面曲线和动态地形估计的可行性的关键见解，以再现地形和盆地演化。