Correlation between the Yarlung Tsangpo River and the Loess Landscape in the Eastern Himalayan Syntaxis

This is the authors' abstract. We don't add key points for this paper.

Thick loess deposits occur in the Linzhi region along the Niyang River, a tributary of the Yarlung Tsangpo River, within the tectonically active Eastern Himalayan Syntaxis. Despite rapid surface uplift and frequent high-magnitude erosion, loess persists in this dynamic environment. Using remote sensing and fieldwork, we mapped loess distribution and traced its provenance through zircon U–Pb dating and heavy mineral analysis. Results show that the loess mainly originates from glacial and fluvial sediments of the Yarlung Tsangpo and Niyang Rivers. Thick loess accumulates on stable glacial erosion platforms and paleodammed lake terraces, while low-lying areas and slopes have limited preservation due to repeated flooding from breached glacial lakes. These floods have reshaped valley floors and influenced sediment redistribution. Our findings reveal how geomorphology, sediment sources, glacial activity, and extreme floods collectively control loess formation and preservation in this mountainous region, providing new insights into loess dynamics in tectonically active, glaciated landscapes.