Contrasting tectonically driven exhumation and incision patterns, western versus central Nepal Himalaya
Contrasting tectonically driven exhumation and incision patterns, western versus central Nepal Himalaya
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对比构造驱动的折返和切割模式，尼泊尔喜马拉雅山西部和中部
DOI：
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
E. Hardwick
中科院分区：
文献类型：
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作者：
P. Beek;C. Litty;M. Baudin;J. Mercier;X. Robert;E. Hardwick
虽然喜马拉雅山脉通常被描述为沿着走向呈圆柱形，但在结构、地形、降水和侵蚀模式方面，喜马拉雅山脉的分段正得到广泛认可。这些横向变化的潜在气候或构造控制仍然存在争议。热动力学模型预测，主要喜马拉雅拆离的几何形状控制的运动学，折返，和地形的造山带：拆离包括一个主要的地壳斜坡，地形显示出陡峭的梯度，重点是地形降水和折返，而地形是温和的，折返不太集中在一个较平坦的拆离。我们通过比较尼泊尔中部的河流切割（特定的水流动力）和长期折返（磷灰石裂变径迹热年代学）的模式来测试这一预测，尼泊尔中部的一个主要地壳斜坡已经通过地球物理方法成像，尼泊尔西部的Karnali河横断带的新勘探数据，预计斜坡将不存在或轻微。我们的研究结果表明，剥露率和河流的切割能力显着较高，集中在尼泊尔中部的地壳斜坡，而他们是较低的，在尼泊尔西部的模式是更分散。这些差异支持一个模型，在该模型中，地形和剥露的横向变化控制的支队的几何形状的变化，并意味着沿走向的气候变化在喜马拉雅山响应构造，而不是驱动它。
Although the Himalayan range is classically presented as cylindrical along strike, segmentation of the range in terms of structure, topography, precipitation, and erosion patterns is becoming widely recognized. The potential climatic or tectonic controls on these lateral variations remain controversial. Thermokinematic models predict that the geometry of the main Himalayan detachment controls the kinematics, exhumation, and topography of the orogen: where the detachment includes a major crustal ramp, the topography shows a steep gradient that focuses orographic precipitation and exhumation, whereas the topography is gentler and exhumation less focused above a flatter detachment. We test this prediction by comparing the patterns of river incision (specific stream power) and long-term exhumation (from apatite fission track thermochronology) in central Nepal, where a major crustal ramp has been imaged by geophysical methods, with new exploratory data from the remote Karnali River transect in western Nepal, where a ramp is predicted to be absent or minor. Our results show that both exhumation rates and river incision capacity are significantly higher and focused on the crustal ramp in central Nepal, whereas they are lower and the pattern is more diffuse in western Nepal. These differences support a model in which lateral variations in topography and exhumation are controlled by variations in the geometry of the detachment, and imply that along-strike climatic variations in the Himalaya respond to tectonics rather than driving it.
影响因子：
18.3
作者：
Elliott, J. R.;Jolivet, R.;Stevens, V. L.
通讯作者：
Stevens, V. L.
印度 Garhwal 喜马拉雅山 10Beâ 侵蚀速率的构造控制
DOI：
10.1002/2013jf002955
发表时间：
2014
期刊：
Journal of Geophysical Research: Earth Surface
影响因子：
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作者：
Scherler;Bookhagen;Strecker
通讯作者：
Strecker