The ice-cored Galena Creek Rock Glacier, Wyoming, USA, has been the subject of a number of studies that sought to determine the origin of its ice. We present new observations of the rock glacier's internal structure from ground-penetrating radar to constrain ice and debris distribution and accumulation. We imaged dipping reflectors in the center of the glacier that are weak and discontinuous, in contrast to strong reflectors toward the edge of the cirque beneath large debris-avalanche chutes. These reflectors form a network of concave-up, up-glacier dipping layers. We interpret these as englacial debris bands formed by large debris falls buried by subsequent ice and snow accumulation. They are discontinuous where ice outpaces debris accumulation, but with sufficient debris accumulation an interleaved pattern of ice and debris layers can form. We propose a model in which the ice in these interleaved layers is snowfall preserved by debris-facilitated accumulation. Large debris falls that occur in early spring bury sections of the snowpack, which are then preserved through summer and incorporated into the rock glacier body over time. This study highlights the importance of sequential accumulation of ice and debris for understanding the dynamics of rock glaciers and debris-covered glaciers.

中文翻译：

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从内部结构的雷达成像中对 Galena Creek Rock Glacier 积冰的新见解

美国怀俄明州的冰芯方铅矿溪岩石冰川一直是许多旨在确定其冰源的研究的主题。我们通过探地雷达对岩石冰川的内部结构进行了新的观察，以限制冰和碎片的分布和积累。我们对冰川中心的倾斜反射器进行了成像，这些反射器微弱且不连续，与大型碎片雪崩滑槽下方的朝向冰轮边缘的强反射器形成对比。这些反射器形成了一个凹形的、上冰川的倾斜层网络。我们将这些解释为由随后的冰雪堆积掩埋的大型碎片形成的冰川碎片带。它们在冰超过碎片积累的地方是不连续的，但如果碎片积累足够多，就会形成冰和碎片层的交错模式。我们提出了一个模型，其中这些交错层中的冰是由碎片促进的积累所保存的降雪。早春发生的大型碎屑坠落掩埋了积雪的一部分，然后在整个夏季保存下来，并随着时间的推移融入岩石冰川体中。这项研究强调了冰和碎片的连续积累对于了解岩石冰川和碎片覆盖的冰川动力学的重要性。