Large-scale aeolian erosion features such as pans usually develop upon a relatively homogeneous erodible sedimentary rock substratum and show simple concave morphologies. However, some erosional depressions in semi-arid to arid settings develop in more complex geological contexts, associating sedimentary basins and outcrops of non-erodible basement. In semi-arid basins, the geomorphic evolution is controlled by interplay between the processes of fluvial erosion and deposition (especially of the finer sediment fraction in ephemeral lakes) and the processes of aeolian erosion and deflation. The occurrence of non-erodible basement outcrops within a region of overall deflation complicates drainage systems and wind-flow patterns. Both are liable to evolve rapidly through time and their interactions remain poorly understood. In this study, we use a detailed geomorphological analysis, including mapping of the aeolian sand-motion direction within the 16,300 km² Tsagaan Els depression (Gobi Desert, Mongolia) as well as in situ-produced cosmogenic ¹⁰Be and ²⁶Al based quantitative constraints, to propose a conceptual model for the morphologic evolution of geologically complex semi-arid basins. Based on theoretical studies of wind-flow patterns around obstacles, we demonstrate that the occurrence of erosion-resistant basement highs inside the basin induces the localization of preferential deflation zones and aeolian and fluvial carving of large-scale relief. The enhanced deflation zones form sub-depocenters controlling local drainage systems that mobilize clastic material and transport it to the deflation zone. These river systems are frequently captured by neighboring streams, which creates unstable conditions of erosion and deposition. Such rapid modifications of the topography through time affect the hydrogeologic structure of the basin and may impact potential sediment-hosted mineral deposits.

大型风沙侵蚀特征（例如平底锅）通常在相对均质的易蚀沉积岩基底上发育，并表现出简单的凹形形态。但是，在更复杂的地质环境中，半干旱至干旱环境中会出现一些侵蚀性凹陷，这与沉积盆地和非易蚀基底的露头有关。在半干旱盆地中，地貌演化受河流冲蚀和沉积过程（特别是短暂湖泊中较细的沉积物部分）与风蚀和放气过程之间的相互作用所控制。在整个通缩区域内非易蚀地下室露头的出现使排水系统和风流模式复杂化。两者都容易随着时间的流逝而迅速发展，它们之间的相互作用仍然知之甚少。在这项研究中，^2个Tsagaan Els洼地（蒙古戈壁沙漠）以及原产的宇宙成因¹⁰ Be和²⁶基于铝的定量约束，为地质复杂的半干旱盆地的形态演化提出概念模型。基于对障碍物周围气流模式的理论研究，我们证明盆地内部抗侵蚀基底高的发生引起了优先放气区的局部化以及大型浮雕的风沙雕刻和河流雕刻。增强的放气区形成子沉积中心，控制局部排水系统，这些排水系统动员碎屑物质并将其运输到放气区。这些河流系统经常被邻近的溪流捕获，这造成了侵蚀和沉积的不稳定条件。地形随时间的这种快速变化会影响盆地的水文地质结构，并可能影响潜在的沉积物蕴藏的矿藏。