Holocene debris-flow deposits and their implications on the climate in the upper Jinsha River valley, China
Holocene debris-flow deposits and their implications on the climate in the upper Jinsha River valley, China
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DOI：
10.1016/j.geomorph.2007.03.011
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发表时间：
2008-01
期刊：
影响因子：
3.9
通讯作者：
Jian Chen;Fuchu Dai;X. Yao
中科院分区：
文献类型：
--
作者：
Jian Chen;Fuchu Dai;X. Yao
金沙江上游干热河谷发育有沿着分布的泥石流沉积。泥石流沉积物，厚度从1到20米不等，总是占据缓倾斜的皮埃蒙特斜坡。沉积物目前被冲沟深深地切割，块体运动的过程几乎停止了。详细的结构、地层和地球化学研究揭示了泥石流的形成过程。根据泥石流堆积体的单元组合特征，识别出7次泥石流事件。光释光（OSL）年龄估计表明，泥石流活动始于10.6kyr BP左右，并逐渐减弱，直至4.5kyr BP，与该地区夏季风明显加强阶段相对应。泥石流堆积物的年龄表明，青藏高原东南缘早全新世以来大量泥石流的发生是对夏季风增强的响应。
Major debris-flow deposits occur along the xerothermic valley of the upper Jinsha River. The debris-flow deposits, ranging in thickness from 1 to 20 m, invariably occupy gently inclined piedmont slopes. The sediments are presently deeply dissected by gullies, and the process of mass movement has almost ceased. Detailed textural, stratigraphical, and geochemical studies reveal the formation processes of the debris flows. Seven debris-flow incidents are noted based on the unit combination characteristics of debris-flow deposits. The age estimates of optically stimulated luminescence (OSL) show that the occurrence of debris flows started at around 10.6 kyr BP and weakened until 4.5 kyr BP, corresponding to the obvious strengthened phase of the summer monsoons in the region. The ages of the debris-flow deposits indicate that the occurrence of a mass of debris flows was a response to the intensified summer monsoon in the SE fringe of the Tibetan Plateau since the early Holocene.