Fossil vertebrates entombed within the Upper Cretaceous Djadokhta Formation of southern Mongolia bear testimony to a heretofore unknown geologic phenomenon: mass wasting of eolian dunes during heavy rainstorms. Evaporation of shallow‐penetrating rainwater led to progressive calcite accumulation in a thin layer of sand about 0.5 m below the surface of dune lee slopes. During rare heavy rainstorms, a perched water table developed at the top of calcitic zones. Positive pore water pressure led to translational slides and fast‐moving sediment gravity flows that overwhelmed animals on the lee slopes of large dunes and in interdune areas.

中文翻译：

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来自风成沙丘的致命滑坡

掩埋在蒙古南部上白垩统 Djadokhta 组内的脊椎动物化石证明了一种迄今为止未知的地质现象：大暴雨期间风成沙丘的大量浪费。浅层渗透雨水的蒸发导致沙丘背风坡表面以下约 0.5 m 的薄沙层中逐渐堆积方解石。在罕见的暴雨期间，在方解石带的顶部形成了栖息的地下水位。正孔隙水压力导致平移滑动和快速移动的沉积物重力流，使大型沙丘的背风坡和沙丘间地区的动物不堪重负。