The Late Quaternary hydroclimatic evolution of lake systems in Mongolia remains unclear. Here we present a record of lake level variations at Orog Nuur in the Valley of Gobi Lakes in southern Mongolia, since the last interglaciation, based on paleo-shoreline dating using quartz optically stimulated luminescence (OSL) and K-feldspar post-infrared infrared stimulated luminescence (pIRIR) signals. Due to feldspar contamination that could not be eliminated, the OSL signals of quartz single-aliquots (SA), except for two Holocene samples, were unsuitable for dating and a double SA regenerative-dose (SAR) protocol was used for the quartz fraction of these two samples. The pIR₅₀IR₁₇₀ and pIR₂₀₀IR₂₉₀ signals of K-feldspar SA were used to date Holocene samples and old samples (>100 ka), respectively, with the SAR protocol. To determine the bleaching condition of the pIR₂₀₀IR₂₉₀ signals, the first pIRIR dating of K-feldspar single-grains of lake shoreline sediments in Mongolia was performed. The equivalent doses of K-feldspar grains show normal distributions, suggesting that the pIR₂₀₀IR₂₉₀ signals are well-bleached. Overall, the results, combined with those of previous studies, show that a mega-lake developed at 56 m above the modern lake level (a.m.l.) during MIS 5e (124.2 ± 6.8–114.7 ± 8.0 ka). Holocene high-stands occurred in the last deglaciation–early Holocene (11.1 ± 1.0 ka) at 23 m a.m.l. and in the mid-Holocene (6.7 ± 0.8–3.3 ± 0.4 ka) at 20–14 m a.m.l. The dimensions of the paleo-lakes were recovered, and a hydrological index indicates that the effective moisture during MIS 5e and the mid-Holocene was 10.7 times and 3.6–5.0 times larger than today, respectively. Finally, the possible mechanisms behind the lake level history are discussed based on correlation with independent paleoclimatic records.

蒙古湖泊系统晚第四纪水文气候演化仍不清楚。在这里，我们展示了自上一次间冰期以来蒙古南部戈壁湖谷奥罗格努尔湖水位变化的记录，基于使用石英光激发发光 (OSL) 和钾长石后红外激发的古海岸线测年发光 (pIRIR) 信号。由于无法消除长石污染，除了两个全新世样品外，石英单等分试样 (SA) 的 OSL 信号不适合测年，因此对石英部分使用双 SA 再生剂量 (SAR) 协议这两个样本。pIR ₅₀ IR ₁₇₀和 pIR ₂₀₀ IR ₂₉₀钾长石 SA 的信号分别用于使用 SAR 协议对全新世样品和旧样品 (>100 ka) 进行测年。为了确定 pIR ₂₀₀ IR ₂₉₀信号的白化条件，对蒙古湖岸沉积物的钾长石单粒进行了首次 pIRIR 测年。钾长石颗粒的等效剂量呈正态分布，表明 pIR ₂₀₀ IR ₂₉₀信号被充分漂白。总体而言，结果与之前的研究结果相结合，表明在 MIS 5e (124.2 ± 6.8 – 114.7 ± 8.0 ka) 期间，在现代湖泊水位 (aml) 上方 56 m 处形成了一个巨型湖泊。全新世高地发生在最后一次冰消期——全新世早期 (11.1 ± 1.0 ka) 在 23 m aml 和全新世中期 (6.7 ± 0.8 - 3.3 ± 0.4 ka) 在 20 - 14 m aml 恢复了古湖泊的尺寸，水文指数表明MIS 5e 和全新世中期的有效水分分别是今天的 10.7 倍和 3.6 – 5.0 倍。最后，基于与独立古气候记录的相关性，讨论了湖泊水位历史背后的可能机制。