Quantifying Tectonic and Glacial Controls on Topography: Patagonia, South America

量化构造和冰川对地形的控制：南美洲巴塔哥尼亚

• 批准号: 313504114
• 负责人: Professor Dr. Todd Alan Ehlers
• 金额: --
• 依托单位: School of Geographical and Earth Sciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/313504114?language=en
• 关键词: Quantifying; Tectonic; Glacial; Controls; Topography

Glacial erosion is hypothesized to exert a first order control on mountain topography. Global correlations between snowline altitudes and orogen hypsometry generally confirm this hypothesis. However, major discrepancies from this trend exist. Tectonic controls on glaciated topography constitute an underappreciated combination of forcing factors that could be the source of these discrepancies and are the focus of this proposal. Recent research suggests the Patagonian Andes are a prime example of a dominant glacial control on variations in topography. However, these topographic variations are associated with a major tectonic boundary characterized by a fourfold drop in convergence rates and oceanic-ridge collision. In this revised proposal, we evaluate the hypothesis that latitudinal topographic variations in the Patagonian Andes are controlled by climate driven gradients in glacial erosion efficiency. Furthermore, we hypothesize that differential rock uplift due to recent faulting driven by oblique ridge collision inboard of the Chilean Triple Junction is linked to observed short-wavelength changes in topography. We will measure new bedrock thermochronometer data from across fault systems with possible displacement linked to oceanic-ridge collision. Detrital thermochronometer data will be collected from latitudinally varying glaciated catchments to quantify elevation dependent variations in glacial erosion. Together, these new (and existing) data will be used to evaluate four end-member testable outcomes that discern the tectonic vs. glacial controls on short wavelength variations in Patagonian topography.

假设冰川侵蚀可以对山地形进行一阶控制。雪地线高度与造成造口催眠之间的全球相关性通常证实了这一假设。但是，存在与这种趋势的主要差异。对冰川地形的构造控制构成了可能是这些差异来源的强迫因素的组合，并且是该提议的重点。最近的研究表明，巴塔哥尼亚安第斯山脉是对地形变化的主要冰川控制的主要例子。但是，这些地形变化与主要的构造边界有关，其特征是收敛速率和海洋ridge碰撞的四倍下降。在这项修订的提案中，我们评估了以下假设：巴塔哥尼亚安第斯山脉的纬度地形变化受气候驱动的冰川侵蚀效率中的梯度控制。此外，我们假设由于智利三重连接板上的倾斜山脊碰撞驱动的最近断层引起的差异岩石提升与观察到的地形短波变化有关。我们将测量来自断层系统的新基岩热量表数据，并可能位移与海洋ridge碰撞有关。碎屑热化学计数据将从纬度变化的冰川流域中收集，以量化冰川侵蚀的高度依赖性变化。总之，这些新的（和现有）数据将用于评估四个末端成员的可测试结果，这些结果辨别了构造构造与冰川控制在巴塔哥尼亚地形中短波长变化上。

项目成果

Effects of slab-window, alkaline volcanism, and glaciation on thermochronometer cooling histories, Patagonian Andes

• DOI: 10.1016/j.epsl.2019.01.030
• 发表时间: 2019-04
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: V. Georgieva;K. Gallagher;A. Sobczyk;E. Sobel;T. Schildgen;T. Ehlers;M. Strecker