Evaluation of the Rock Uplift Pattern in the Central Yunnan Subblock, SE Tibetan Plateau: Based on the Bedrock Channel Profile
Evaluation of the Rock Uplift Pattern in the Central Yunnan Subblock, SE Tibetan Plateau: Based on the Bedrock Channel Profile
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DOI：
10.3389/feart.2022.821367
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
Lianyong Yu;Youpu Dong;Weiwei Zhou;Dongyue Zhang;Dan Wang;Hua Yu;Yan Ren;Jiangtao Li
中科院分区：
文献类型：
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作者：
Lianyong Yu;Youpu Dong;Weiwei Zhou;Dongyue Zhang;Dan Wang;Hua Yu;Yan Ren;Jiangtao Li
青藏高原东南部的隆升格局与印度-欧亚碰撞的地形演化密切相关。然而，应变是沿着包围大型构造块体的主要断层定位的，还是跨地区容纳的，一直存在激烈的争论。在这项研究中，我们使用水流功率切割模型来获得渠道陡度指数的分布规律，以了解整个地区的岩石抬升模式，因为增加的渠道陡度指数往往与岩石抬升速率相关。通过对河流纵剖面的分析，得出了滇中亚块河道陡度指数的分布规律。结果表明，陡度指数与岩性、降雨量、泥沙通量或河道凹陷指数之间的相关性很弱。沿小江走滑断裂和内部亚块，抬升速率较慢，北部抬升较快，受逆冲断裂系统控制。航道陡度自南向北逐渐增大。因此，滇中亚块内归一化航道陡度k、sn指数的分布格局，为青藏高原冲断改造限制挤压模式的论证提供了有力的支持。
The uplift pattern of the southeastern Tibetan Plateau is strongly related to the topographic evolution stemming from the India–Eurasia collision. However, whether strain is localized along major faults that bound large tectonic blocks or is accommodated across regions has been strongly debated. In this study, we used stream power incision models to obtain the distribution pattern of the channel steepness indices to understand the rock uplift pattern across the area, as increased channel steepness indices often correlate with the rock uplift rates. In this study, the river longitudinal profiles were analyzed to obtain the distribution of the channel steepness indices in the Central Yunnan subblock. The results suggested very weak correlations between the steepness indices and the lithology, precipitation, sediment flux, or channel concavity indices. Along the Xiaojiang strike–slip fault and the interior subblock, the uplift rate was slower, while the northern part had uplifted faster and was controlled by thrust fault systems. The channel steepness increased gradually from south to north. Thus, the distribution pattern of the normalized channel steepness, k sn, index within the Central Yunnan subblock provides notable support for the argument for the thrusting transformation-limited extrusion model of the Tibetan Plateau.