The Quaternary paleoenvironmental history of the Arctic Ocean remains uncertain, mainly due to the limited chronological constraints, especially beyond the ¹⁴C dating limits of accelerator mass spectrometry (AMS). The difficulty in establishing reliable chronostratigraphies is mainly attributed to low sedimentation rates and diagenetic sediment changes, resulting in very poor preservation of microfossils and altered paleomagnetic records. In the absence of independent chronostratigraphic data, the age model of Pleistocene sediments from the Arctic Ocean is mainly based on cyclostratigraphy, which relates lithologic changes to climatic variability on orbital time scales. In this study, we used the Mn/Al record measured from the sediment core ARA03B-41GC retrieved from the Makarov Basin in the western Arctic Ocean. The Mn/Al variation was tuned to the global benthic oxygen isotope stack (LR04) curve under different assumptions for computational correlation. Regardless of assumptions, our computational approach led to similar ages of about 600–1,000 ka for the bottom part of the core. These age models were up to about 200 ka older than those derived from lithostratigraphic approaches. Interestingly, our new age models show that the Ca/Al peak, a proxy for a detrital input from the Laurentide Ice Sheet, first occurred about 150 ka earlier than those previously proposed. Therefore, our results suggest that the glaciers in northern North America developed more extensively at about 810 ka than in earlier glacial periods, and influenced the sedimentary and paleoceanographic environments of the Arctic Ocean much earlier than previously thought. In order to establish a more comprehensive age model, more work is needed to validate our findings with different sediment cores recovered from the western Arctic Ocean.

北冰洋第四纪古环境历史仍然不确定，这主要是由于时间限制有限，尤其是在¹⁴加速器质谱（AMS）的C约会限制。建立可靠的年代地层的困难主要归因于低沉积速率和成岩沉积变化，导致微化石的保存非常差，古地磁记录也发生了变化。在缺乏独立的年代地层数据的情况下，来自北冰洋的更新世沉积物的年龄模型主要是基于旋回地层学，它把岩性变化与轨道时标上的气候变化联系起来。在这项研究中，我们使用了从北冰洋西部马卡罗夫盆地取回的沉积物芯ARA03B-41GC测得的Mn / Al记录。在不同的计算假设下，将Mn / Al的变化调整为总体底栖氧同位素堆栈（LR04）曲线。不管假设如何 我们的计算方法导致岩心底部的相似年龄大约为600–1,000 ka。这些年龄模型比采用岩石地层学方法得出的年龄模型高出约200 ka。有趣的是，我们的新年龄模型显示，Ca / Al峰是Laurentide冰盖的碎屑输入的替代物，它比先前提出的最早出现时间早了约150 ka。因此，我们的结果表明，北美洲北部的冰川在大约810 ka时比早期的冰川时期发展得更为广泛，并且对北冰洋的沉积和古海洋环境的影响要比以前认为的要早得多。为了建立更全面的年龄模型，需要进行更多的工作来验证我们从北冰洋西部地区回收的不同沉积岩心的发现。