Earth’s surface is deficient in available forms of many elements considered limiting for prebiotic chemistry. In contrast, many extraterrestrial rocky objects are rich in these same elements. Limiting prebiotic ingredients may, therefore, have been delivered by exogenous material; however, the mechanisms by which exogeneous material may be reliably and non-destructively supplied to a planetary surface remains unclear. Today, the flux of extraterrestrial matter to Earth is dominated by fine-grained cosmic dust. Although this material is rarely discussed in a prebiotic context due to its delivery over a large surface area, concentrated cosmic dust deposits are known to form on Earth today due to the action of sedimentary processes. Here we combine empirical constraints on dust sedimentation with dynamical simulations of dust formation and planetary accretion to show that localized sedimentary deposits of cosmic dust could have accumulated in arid environments on early Earth, in particular glacial settings that today produce cryoconite sediments. Our results challenge the widely held assumption that cosmic dust is incapable of fertilizing prebiotic chemistry. Cosmic dust deposits may have plausibly formed on early Earth and acted to fertilize prebiotic chemistry.

地球表面缺乏许多被认为限制生命起源化学的可用元素。相比之下，许多外星岩石物体富含这些相同的元素。因此，有限的益生元成分可能是通过外源物质传递的；然而，外源物质可靠且非破坏性地供应到行星表面的机制仍不清楚。如今，流向地球的外星物质主要是细粒宇宙尘埃。尽管这种材料由于其在大表面积上的输送而很少在生命起源的背景下讨论，但由于沉积过程的作用，目前已知地球上会形成浓缩的宇宙尘埃沉积物。在这里，我们将尘埃沉降的经验约束与尘埃形成和行星吸积的动态模拟结合起来，表明宇宙尘埃的局部沉积物可能在早期地球的干旱环境中积累，特别是今天产生冰石沉积物的冰川环境。我们的结果挑战了人们普遍持有的假设，即宇宙尘埃无法为生命起源前的化学物质提供肥料。宇宙尘埃沉积物可能在早期地球上形成，并为生命起源前的化学物质提供了肥沃的土壤。