Some of the largest catastrophic outbursts of periglacial lakes known in the geological history of the Earth have been identified in the Altai Mountains. Traces of these events are recorded in the form of large terraces, predominantly composed of gravel material with numerous horizons of large boulders and blocks. Determining the age of these large-scale events is difficult due to the lack of suitable material (e.g. organics, well-bleached sand) and the specific genesis of these sediments. The results of cosmogenic radionuclide dating suggest a post-LGM age both for the source of the flood water and for different elements of the catafluvial terraces in the Chuya and Katun river valleys. Nevertheless, the age(s) of catastrophic breakthrough remains controversial. On the basis of a few IRSL ages, and geological and other evidence, some view the event as occurring around MIS 5. In this study, we investigate loess-like loams overlying the catafluvial sediments on the surface of the highest level terrace, ∼200 m above present river level. A total of 24 samples for luminescence dating were obtained, for which the OSL, IR₅₀, and pIRIR_50,290 signals were measured to control the degree of signal zeroing and the dating reliability. The age of the loess in all three pits was from 0.5 ka at the top to 23 ka at the base of the loess strata. From a sand layer in the top of the catafluvial deposits, two ages of ∼85–90 ka were obtained from feldspar pIRIR_50,290. These results provide a minimum pre-LGM age for the geomorphological surface of a major catafluvial terrace in the Altai Mountains.

在阿尔泰山脉发现了地球地质史上已知的一些最大的冰缘湖灾难性爆发。这些事件的痕迹以大梯田的形式记录下来，主要由砾石材料组成，具有大量的大石头和块体。由于缺乏合适的材料（例如有机物、漂白良好的沙子）和这些沉积物的特定成因，确定这些大规模事件的年龄很困难。宇宙成因放射性核素测年的结果表明，洪水的来源和 Chuya 和 Katun 河谷的河流阶地的不同元素都存在后 LGM 时代。然而，灾难性突破的年龄仍然存在争议。根据一些 IRSL 年龄，以及地质和其他证据，一些人认为该事件发生在 MIS 5 附近。在这项研究中，我们调查了位于目前河流水位以上约 200 米的最高层台地表面上的河流沉积物上的黄土状壤土。共获得 24 个样品进行发光测年，其中 OSL、IR_测量50和 pIRIR _50,290信号以控制信号归零程度和测年可靠性。三个坑的黄土年龄均为黄土地层顶部0.5 ka至底部23 ka。从流变沉积物顶部的砂层中，从长石 pIRIR _50,290获得了两个年龄约为 85-90 ka 的年龄。这些结果为阿尔泰山脉主要河流阶地的地貌表面提供了 LGM 前的最小年龄。