Rock glaciers, usually preserved in periglacial environments of cold-climate high-relief regions, are useful (palaeo)climate indicators. In the European Alps, numerous studies have focused on describing these geomorphological features. However, very few have attempted directly dating them. This lack of measurement is particularly evident in the French Alps. To fill this gap, we performed Cosmic Ray Exposure (CRE) dating through beryllium-10 (¹⁰Be) on 10 granitic rock samples collected from two relict rock glaciers, hereafter referred as RG1 and RG2, located at col du Lautaret in the French Alps. This first CRE dating of rock glaciers in the French Alps yielded mean ages of 11.8 ± 0.5 kyrs and 11.6 ± 0.6 kyrs for RG1 and RG2, respectively. While RG2 is clearly a talus-derived rock glacier, the origin of RG1 is less clear. It could potentially be talus-derived, glacier-derived or of mixed origin. The ¹⁰Be ages indicate that both rock glaciers became inactive during the transition between the Younger Dryas and the onset of the Holocene, consistently with other studies in the Northern Hemisphere. Considering surface velocity measurements carried out since the 1980s on neighbouring rock glaciers, we hypothesise that the rock glaciers were formed either during the Younger Dryas or slightly earlier, between the Heinrich Stadial 1 and the Younger Dryas. During this period, we estimated temperatures ~3.6 °C lower than the 1980s and precipitation up to 30% lower than at present.

岩石冰川通常保存在寒冷气候高地貌区的冰缘环境中，是有用的（古）气候指标。在欧洲阿尔卑斯山，许多研究都集中在描述这些地貌特征上。然而，很少有人尝试直接与他们约会。这种缺乏测量在法国阿尔卑斯山尤为明显。为了填补这一空白，我们通过铍 10 ( ¹⁰Be) 在从位于法国阿尔卑斯山 col du Lautaret 的两个残岩冰川（以下称为 RG1 和 RG2）收集的 10 块花岗岩岩石样品上。对法国阿尔卑斯山岩石冰川的首次 CRE 测年得出 RG1 和 RG2 的平均年龄分别为 11.8 ± 0.5 kyrs 和 11.6 ± 0.6 kyrs。虽然 RG2 显然是距骨衍生的岩石冰川，但 RG1 的起源不太清楚。它可能来自距骨、冰川或混合来源。在¹⁰Be 年龄表明，在新仙女木和全新世开始之间的过渡期间，两个岩石冰川都变得不活跃，这与北半球的其他研究一致。考虑到自 1980 年代以来对邻近岩石冰川进行的表面速度测量，我们假设岩石冰川形成于年轻的仙女木期间或稍早一些，位于海因里希斯塔迪尔 1 和新仙女木之间。在此期间，我们估计温度比 1980 年代低约 3.6 °C，降水量比现在低 30%。