Abstract The Suwalong section of the upper Jinsha River is located on the southeastern margin of the Tibetan Plateau. Affected by the rapid uplift of the Tibetan Plateau, steep slopes have been formed by the rapid downcutting of rivers in this section. Tectonically, the Suwalong section is located in the Jinshajiang suture zone and features intense tectonic activity, making this section prone to geological disasters such as landslides. Through field investigation, four old accumulation bodies were found in the Suwalong section, and lacustrine sediments were observed upstream of these bodies. By analysing the surrounding landforms, appearance features, and internal rocks of the old accumulation bodies, we conclude that these four old accumulation bodies represent the remains of dams that blocked the river. These dams formed through the deposition of rockslides, rock avalanches, or debris flows that occurred on the slopes on both sides of the river. By comparing the top elevation information and the chemical and mineral compositions of the lacustrine sediments around these residual dams, the order of the demise of two dammed lakes was obtained, and the order was confirmed by optically stimulated luminescence (OSL) dating. The method in this paper has great applicability for identifying river-blocking events in other regions.

中文翻译：

---

青藏高原东南部金沙江上游苏瓦龙段古拦河事件识别及滑坡坝形成机制分析

摘要 金沙江上游苏瓦龙段位于青藏高原东南缘。受青藏高原快速抬升的影响，该段河流快速下切形成陡坡。从构造上看，苏瓦龙段位于金沙江缝合带，构造活动强烈，容易发生滑坡等地质灾害。通过野外调查，在苏瓦龙断面发现了4个古老的堆积体，在这些堆积体的上游观察到了湖相沉积物。通过对旧堆积体的周边地貌、外观特征和内部岩石的分析，我们得出结论，这四个旧堆积体代表了拦河大坝的遗迹。这些大坝是由河流两侧斜坡上发生的岩崩、岩崩或泥石流沉积而成的。通过比较这些残坝周围湖底沉积物的顶部高程信息和化学矿物成分，得出两个堰塞湖的消亡顺序，并通过光激发光（OSL）测年确认了该顺序。本文提出的方法对于识别其他地区的堵河事件具有很大的适用性。并且通过光学受激发光（OSL）测年证实了该顺序。本文提出的方法对于识别其他地区的堵河事件具有很大的适用性。并且通过光学受激发光（OSL）测年证实了该顺序。本文提出的方法对于识别其他地区的堵河事件具有很大的适用性。