收藏设为首页 广告服务联系我们在线留言

干旱区地理 ›› 2026, Vol. 49 ›› Issue (8): 1675-1686.doi: 10.12118/j.issn.1000-6060.2025.676 cstr: 32274.14.ALG2025676

• 地表过程研究 • 上一篇    下一篇

雅鲁藏布江河流沉积物矿物成熟度的演化过程及物源示踪

陈锋1(), 夏诗瑶1, 任娇2   

  1. 1 山西财经大学资源环境学院山西 太原 030006
    2 山西财经大学资源型经济转型发展研究院山西 太原 030006
  • 收稿日期:2025-10-22 修回日期:2025-12-05 出版日期:2026-08-25 发布日期:2026-08-21
  • 作者简介:陈锋(1988-),男,博士,教授,主要从事区域环境变化等方面的研究. E-mail: chenfeng@sxufe.edu.cn
  • 基金资助:
    第二次青藏高原综合科学考察研究项目(2019QZKK0605);国家自然科学基金(41701224);山西省基础研究计划项目(202403021211055)

Evolutionary process of mineral maturity and provenance tracing of sediments in the Yarlung Zangbo River

CHEN Feng1(), XIA Shiyao1, REN Jiao2   

  1. 1 School of Resources and Environment, Shanxi University of Finance and Economics, Taiyuan 030006, Shanxi, China
    2 Research Institute of Transition of Resource-Based Economics, Shanxi University of Finance and Economics, Taiyuan 030006, Shanxi, China
  • Received:2025-10-22 Revised:2025-12-05 Published:2026-08-25 Online:2026-08-21

摘要:

聚焦青藏高原雅鲁藏布江表层沉积物,剖析其物源及演化过程。通过系统采集河流沉积物样品,结合高精度化学分析技术,采用球粒陨石标准化方法,利用δEu、La/Yb、Rb/Sr等指标以及多元图解,开展地球化学特征、演化过程及物源解析。结果表明:(1) 雅鲁藏布江流域表层沉积物稀土元素总含量总体较高,稀土元素分布呈现轻稀土显著富集、Eu典型负异常、Ce无明显异常的特征。(2) 流域风化作用存在明显空间差异,上游区域以物理风化作用为主导,下游区域则以化学风化作用为主导。(3) 从上游至下游,沉积物矿物分选作用逐步增强,矿物成熟度呈现显著递增趋势。(4) 地球化学混合模型结果显示,研究区沉积物的物源主要由喜马拉雅造山带变泥质岩(占89.7%)、喜马拉雅淡色花岗岩(占8.3%)和冈底斯岩基花岗岩(占2.3%)共同贡献。研究结果可为区域构造演化过程及物质迁移规律研究提供重要的地球化学支撑依据。

关键词: 雅鲁藏布江, 河流表层沉积物, 微量元素, 稀土元素

Abstract:

Focusing on the surface sediments of the Yarlung Zangbo River in the Qinghai-Xizang Plateau, this study analyzes their provenance and evolutionary processes. River sediment samples were systematically collected and analyzed using high-precision geochemical analytical techniques. Chondrite normalization, along with elemental ratios such as δEu, La/Yb, and Rb/Sr, and multivariate diagrams, were employed to characterize geochemical features, reconstruct evolutionary processes, and determine sediment provenance. The results show that: (1) The total content of rare earth elements (∑REE) in this basin is generally high. The distribution of REEs is characterized by significant enrichment of light rare earth elements, a typical negative Eu anomaly, and no obvious Ce anomaly. (2) There are clear spatial variations in weathering processes across the basin: Physical weathering dominates in the upper reaches, whereas chemical weathering becomes dominant in the lower reaches. (3) From the upper to the lower reaches, the mineral sorting of sediments gradually increases, and mineral maturity shows a significant increasing trend. (4) The geochemical mixing model shows that the provenance of sediments in the study area is mainly derived from metamorphic argillaceous rocks of the Himalayan orogenic belt (89.7%), with additional contributions from Himalayan leucogranites (8.3%) and Gangdese batholith granites (2.3%). These results provide important geochemical evidence for understanding regional tectonic evolution processes and sediment transport mechanisms.

Key words: Yarlung Zangbo River, river surface sediments, trace elements, rare earth elements