Topographic advection on fault-bend folds: Inheritance of valley positions and the formation of wind gaps
Topographic advection on fault-bend folds: Inheritance of valley positions and the formation of wind gaps
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断层弯曲褶皱上的地形平流：山谷位置的继承和风隙的形成
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Rudy Slingerland
中科院分区：
文献类型：
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作者：
Scott R. Miller;Rudy Slingerland
沿着任何单个线状山脉或断块的两侧形成的流域盆地通常被观察到在平台上自相似，均匀间隔，在某些情况下与相对侧面的流域盆地对齐。来自尼泊尔Siwalik山的数据说明了这个组织，那里的流域和山谷在主分水岭上排列。我们认为，山谷排列是地形平流穿过分水岭的结果。为了探索这一假设，研究人员利用断层弯曲褶皱的景观演化模型进行了数值实验，该模型模拟了受分离限制的河流切割和线性山坡扩散。结果表明，裂谷的存在和基岩运动的横向分量是地形平流越过裂谷的必要和充分条件，这是形成风隙和山脊远侧山谷间距从近侧继承而来的机制。这种地形继承是由低岩石可蚀性、低降水率、快速基岩速度和/或中间断层倾角促进的。
Drainage basins formed along the flanks of any individual linear mountain range or fault block are commonly observed to be self-similar in planform, uniformly spaced, and in some cases aligned with drainage basins on the opposing flank. Data from the Siwalik Hills, Nepal, illustrate this organization where drainage basins and valleys are aligned across the main divide. We suggest that valley alignment is a consequence of advection of topography across the divide. To explore this hypothesis, numerical experiments were conducted using a landscape evolution model of a fault-bend fold that simulates detachment-limited stream incision and linear hillslope diffusion. Results show that the presence of incised valleys and a lateral component of bedrock motion are necessary and sufficient conditions for advection of relief across the divide, a mechanism by which wind gaps form and valley spacing on the far side of a ridge is inherited from that on the near side. This topographic inheritance is promoted by low rock erodibility, low precipitation rates, fast bedrock velocities, and/or intermediate fault dips.