The south of Western Siberia is an important part of the Eurasian loess belt, containing an extensive record of Quaternary landscape and climate evolution in up to 100 m thick loess deposits with as many as 10 pedocomplexes. However, this important Quaternary archive lacks a reliable absolute chronology, and this has prevented the linking of the widely accepted regional chronostratigraphic correlations with those of other parts of the Eurasian loess belt. Here we present the first results of detailed luminescence dating of the Late Pleistocene loess-palaeosol sequence at the Western Siberian stratotype section of Lozhok. According to the classical regional chronostratigraphic scheme, this sequence records the main stages of the environmental evolution of the region, including three palaeosols correlated with the warming stages of MIS 5e, MIS 5c and MIS 3. Our absolute chronology is based on 38 new luminescence ages (OSL, IR₅₀, pIRIR₂₉₀). Good agreement between the OSL and pIRIR₂₉₀ ages suggests sufficient bleaching before deposition. The resulting chronology reveals that, rather than being only Upper Pleistocene in age, the loess-palaeosol sequence at Lozhok actually formed in the Middle and Upper Pleistocene. The ages of individual horizons do not correspond to the previously accepted stratigraphic units and morphological features of pedocomplexes. Our Bayesian chronological model reveals remarkable variation in dust accumulation and preservation at the site. The new results unambiguously identify the presence of an erosional boundary with a hiatus lasting ∼90 ka. The upper pedocomplex, immediately below this discontinuity, formed in sediment deposited between 131 ± 9 ka and 122 ± 11 ka and clearly corresponds to MIS 5. The lower pedocomplex is found in sediment deposited between 240 ± 12 and 199 ± 9 ka, and correlates closely with MIS 7. These new findings demonstrate the urgent need for a wider programme to date the main stratotypes of loess-palaeosol sections in Western Siberia. Only then can the global implications of the regional climate record in this important continental-scale archive be correctly interpreted.

西西伯利亚南部是欧亚黄土带的重要组成部分，在多达100 m厚的黄土沉积物中包含多达10个土壤复合体的第四纪景观和气候演变的广泛记录。然而，这个重要的第四纪档案缺乏可靠的绝对年代学，这阻碍了广泛接受的区域年代地层相关性与欧亚黄土带其他部分的联系。在这里，我们展示了 Lozhok 西西伯利亚层型剖面晚更新世黄土-古土壤序列的详细发光测年结果。根据经典的区域年代地层方案，该序列记录了该区域环境演化的主要阶段，包括与MIS 5e变暖阶段相关的三个古土壤，₅₀ , pIRIR ₂₉₀ )。OSL 和 pIRIR _{290之间的良好一致性}年龄表明沉积前有足够的漂白。由此产生的年代学表明，Lozhok 的黄土-古土壤层序实际上形成于中更新世和上更新世，而不仅仅是上更新世。个别层位的年龄与先前公认的地层单位和土壤复合体的形态特征不对应。我们的贝叶斯年代模型揭示了现场灰尘积累和保存的显着变化。新结果明确地确定了存在持续约 90 ka 间断的侵蚀边界。上层土壤复合体，紧接在该不连续性下方，形成于沉积在 131 ± 9 ka 和 122 ± 11 ka 之间的沉积物中，并且明显对应于 MIS 5。下部土壤复合体发现于沉积在 240 ± 12 和 199 ± 9 ka 之间的沉积物中，并与 MIS 7 密切相关。这些新发现表明迫切需要更广泛的计划来确定西西伯利亚黄土-古土壤剖面的主要层型。只有这样，才能正确解释这一重要大陆尺度档案中区域气候记录的全球影响。