Central Asia is a substantial source of long-range-transported dust, yet the historical and geological variability of dust activity in this region remains poorly understood. This study presents a Holocene record of dust activity from a 6.2-m loess section located near Tashkent in the westerlies-dominated region of eastern Uzbekistan, Central Asia. Utilizing the quartz optically stimulated luminescence dating protocol, we employed grain-size analysis and trace-element geochemistry to reconstruct Holocene dust activity. Dating indicated that this section was deposited over the last 9.6 ka. Four grain-size end-member (EM) components were identified, each representing different atmospheric circulation patterns and sedimentary environments. End-member 2, with a modal size of 11.2 μm, likely represents particles transported by upper-level westerlies, while EM 3, with a modal size of 28.3 μm, is associated with near-surface winds linked to dust storms. Zirconium is concentrated in coarse particles, whereas Rb is enriched in finer particles during dust deposition. Therefore, higher Zr/Rb ratios indicate stronger or more distant dust transport; hence, the Zr/Rb ratio is a reliable indicator of dust activity. Holocene dust activity was reconstructed using the EM 3 component and Zr/Rb ratio, revealing several extreme dust-storm events. During the early–middle Holocene (9.6–5 ka), dust activity was stronger but less frequent compared with the subsequent shift to lower intensity but higher frequency dust events. The long-term orbital-scale decline in Holocene dust activity can be attributed to reduced solar insolation and weakening of the Siberian High since the early Holocene. On a centennial to millennial scale, extreme dust-storm events are teleconnected with cold ice-rafted debris events in the North Atlantic. Projections for the coming century suggest that dust activity in eastern Uzbekistan may further decline, accompanied by an increase in precipitation. This study provides new insights into understanding and predicting dust storms in Central Asia.

中文翻译：

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对乌兹别克斯坦东部全新世尘埃活动的新见解


中亚是远距离运输沙尘的重要来源，但人们对该地区沙尘活动的历史和地质变化仍然知之甚少。本研究展示了位于中亚乌兹别克斯坦东部西风区以西风为主的塔什干附近 6.2 m 黄土剖面的全新世尘埃活动记录。利用石英光刺激发光测年方案，我们采用晶粒尺寸分析和微量元素地球化学来重建全新世尘埃活动。测年表明，该部分沉积于最后 9.6 ka 年。确定了四个粒度的端元 （EM） 成分，每个成分代表不同的大气环流模式和沉积环境。模态尺寸为 11.2 μm 的端元 2 可能代表由高层西风带传输的粒子，而模态尺寸为 28.3 μm 的 EM 3 与与沙尘暴相关的近地表风有关。锆集中在粗颗粒中，而 Rb 在粉尘沉积过程中富含较细的颗粒。因此，较高的 Zr/Rb 比值表明尘埃传输更强或更远;因此，Zr/Rb 比值是粉尘活动的可靠指标。使用 EM 3 分量和 Zr/Rb 比值重建全新世沙尘活动，揭示了几次极端沙尘暴事件。在全新世早期至中期 （9.6-5 ka），与随后转向强度较低但频率较高的沙尘事件相比，沙尘活动更强但频率更低。全新世尘埃活动的长期轨道尺度下降可归因于全新世早期以来太阳日照的减少和西伯利亚高压的减弱。 在百年到千年的尺度上，极端沙尘暴事件与北大西洋的寒冷冰筏碎片事件遥相关。对未来世纪的预测表明，乌兹别克斯坦东部的沙尘活动可能会进一步减少，同时降水也会增加。本研究为理解和预测中亚沙尘暴提供了新的见解。