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OA

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 collect-ed and analyzed using high-precision geochemical analytical techniques.Chondrite normalization,along with ele-mental ratios such as δEu,La/Yb,and Rb/Sr,and multivariate diagrams,were employed to characterize geochemi-cal 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 character-ized 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 dom-inates 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 re-sults provide important geochemical evidence for understanding regional tectonic evolution processes and sedi-ment transport mechanisms.