Catastrophic drainage of ice-dammed lakes in the Altai Mountains has been inferred from geomorphological evidence in the Katun Valley (Russia), and is presumed to have occurred during the Pleistocene. The sedimentary features have been difficult to date directly, due to the absence of organic carbon, and the improbability that luminescence signals in sand grains would be reset during transport. However, the development of rock-surface luminescence dating provides a new opportunity to date the features: clasts have a different transport history to sand grains, and their luminescence depth profiles can be inspected for evidence of bleaching before burial. Here we investigate two sites in the Altai Mountains, and use rock-surface luminescence burial dating to constrain the age of the megaflood deposits. In the Katun Valley, we sampled granite cobbles from a frozen sediment clast emplaced as a dropstone within a massive megaflood gravel terrace. Burial ages for the clasts range from 16.7 to 21.4 ka, with a mean age of 19.8 ± 1.5 ka. This represents the depositional age of the fluvial sediments that preceded the lake outburst flood, (and hence places a maximum age on the catastrophic flood). Clasts sampled from mega-ripples in the Kurai Basin are shown to have a mid-to-late Holocene burial age, which is not consistent with the possible origin of these features during a catastrophic drainage of a glacier-dammed lake. Instead, the burial age of the Kurai Basin sediments may reflect local-scale periglacial or seismic processes along the Kurai Fault Zone.

阿尔泰山脉冰坝湖泊的灾难性排水已从卡顿河谷（俄罗斯）的地貌证据中推断出来，并推测发生在更新世期间。由于缺乏有机碳，而且砂粒中的发光信号在运输过程中不太可能被重置，因此很难直接确定沉积特征的年代。然而，岩石表面发光测年的发展为确定这些特征提供了一个新的机会：碎屑具有与沙粒不同的传输历史，并且可以在埋葬前检查它们的发光深度剖面以寻找白化的证据。在这里，我们调查了阿尔泰山脉的两个地点，并使用岩石表面发光埋藏测年来限制大洪水沉积物的年龄。在卡顿河谷，我们从一个冰冻的沉积碎屑中采集了花岗岩鹅卵石，这些碎屑是一个巨大的巨型洪水砾石台地中的一块落石。碎屑的埋藏年龄为 16.7 至 21.4 ka，平均年龄为 19.8 ± 1.5 ka。这代表了湖泊溃决洪水之前河流沉积物的沉积年龄（因此将最大年龄置于灾难性洪水上）。从库拉伊盆地的巨型涟漪中取样的碎屑显示具有全新世中晚期的埋藏年龄，这与冰川堰塞湖的灾难性排水过程中这些特征的可能起源不一致。相反，库莱盆地沉积物的埋藏年龄可能反映了库莱断裂带沿线的局部冰缘或地震过程。碎屑的埋藏年龄为 16.7 至 21.4 ka，平均年龄为 19.8 ± 1.5 ka。这代表了湖泊溃决洪水之前河流沉积物的沉积年龄（因此将最大年龄置于灾难性洪水上）。从库拉伊盆地的巨型涟漪中取样的碎屑显示具有全新世中晚期的埋藏年龄，这与冰川堰塞湖的灾难性排水过程中这些特征的可能起源不一致。相反，库莱盆地沉积物的埋藏年龄可能反映了库莱断裂带沿线的局部冰缘或地震过程。碎屑的埋藏年龄为 16.7 至 21.4 ka，平均年龄为 19.8 ± 1.5 ka。这代表了湖泊溃决洪水之前河流沉积物的沉积年龄（因此将最大年龄置于灾难性洪水上）。从库拉伊盆地的巨型涟漪中取样的碎屑显示具有全新世中晚期的埋藏年龄，这与冰川堰塞湖的灾难性排水过程中这些特征的可能起源不一致。相反，库莱盆地沉积物的埋藏年龄可能反映了库莱断裂带沿线的局部冰缘或地震过程。从库拉伊盆地的巨型涟漪中取样的碎屑显示具有全新世中晚期的埋藏年龄，这与冰川堰塞湖的灾难性排水过程中这些特征的可能起源不一致。相反，库莱盆地沉积物的埋藏年龄可能反映了库莱断裂带沿线的局部冰缘或地震过程。从库拉伊盆地的巨型涟漪中取样的碎屑显示具有全新世中晚期的埋藏年龄，这与冰川堰塞湖的灾难性排水过程中这些特征的可能起源不一致。相反，库莱盆地沉积物的埋藏年龄可能反映了库莱断裂带沿线的局部冰缘或地震过程。