Aeolian sediments and other surface deposits are widespread along the broad valleys across the Yarlung Tsangpo (YT) catchment on the southern Tibetan Plateau (TP) and are considered important sources of global dust. However, geochemical differentiation in different reaches, sedimentary circulation, and dust transmission processes in the YT valleys are poorly understood. In this study, 47 samples of different types of sediments were collected from different YT valleys, and the major and trace-element (excluding rare-earth elements, REEs) compositions of 42 bulk samples and the trace elements (including REEs) compositions for the fine (< 75 μm) fractions of 21 samples were determined. The results show that the different sediments are predominantly sourced from local felsic bedrocks, originating mainly from the Lhasa terrane through the tributary systems, which are primarily controlled by the physical weathering, and only incipient chemical weathering. The geochemical characteristics of the various sediment types exhibited spatial differentiation because of the complex structure and topography, intense surface circulation, and mixing processes of the detritus from both banks. Owing to the complexity of regional surface processes, conventional non-isotopic geochemical methods might not be the most effective tool for sediment provenance tracing on a large spatial scale. Nevertheless, aeolian deposits in the broad valleys across YT mainly have a near-source clastic supply of local origins, belonging to a regional self-cycling process, which might not be transported by wind across different reaches because of high topographic obstacles.

风积沉积物和其他地表沉积物分布在青藏高原南部 (TP) 雅鲁藏布江 (YT) 流域的广阔山谷中，被认为是全球灰尘的重要来源。然而，人们对YT河谷不同河段的地球化学分异、沉积环流和沙尘传播过程知之甚少。本次研究从不同的YT河谷采集了47个不同类型沉积物样品，对42个大块样品的主量和微量元素（不含稀土元素，REEs）组成以及微量元素（包括REEs）组成进行了分析。测定了 21 个样品的细 (< 75 μm) 级分。结果表明，不同的沉积物主要来源于当地的长英质基岩，主要来自拉萨地体通过支流系统，主要受物理风化控制，只有初期的化学风化作用。由于两岸碎屑结构和地形复杂，地表环流强烈，混合过程不同，不同沉积物类型的地球化学特征呈现出空间分异性。由于区域地表过程的复杂性，传统的非同位素地球化学方法可能不是大空间尺度上沉积物来源追踪的最有效工具。尽管如此，YT 宽阔河谷中的风积沉积物主要具有本地来源的近源碎屑供应，属于区域性自循环过程，