DETERMINING RATES OF LANDSCAPE RESPONSE TO TECTONIC FORCING ACROSS A RANGE OF TEMPORAL SCALES AND EROSIONAL MECHANISMS: TETON RANGE, WY
DETERMINING RATES OF LANDSCAPE RESPONSE TO TECTONIC FORCING ACROSS A RANGE OF TEMPORAL SCALES AND EROSIONAL MECHANISMS: TETON RANGE, WY
复制标题
确定一系列时间尺度和侵蚀机制的景观对构造强迫的响应率：怀俄明州提顿山脉
DOI：
10.13023/etd.2019.310
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Meredith L. Swallom
中科院分区：
文献类型：
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作者：
Meredith L. Swallom
地形地貌对不同时间尺度的构造强迫的响应率和侵蚀机制：提顿山脉，怀俄明州了解山地景观如何对活动山地带中不同时间尺度的构造强迫变化做出响应，仍然是构造和地貌研究中的一个突出挑战。虽然一些经验和数值研究已经审查了这个问题，其中许多是复杂的规模和气候变化的问题。更具体地说，河流和冰川侵蚀的相对效率，这大概是由气候控制，很难解开。怀俄明州的提顿山脉是地壳规模的提顿断层运动的结果，是解决这一挑战的理想天然实验室，因为构造隆起边界条件和隆起沿着走向的变化在以前的研究中得到了充分的记录，并且由于其相对较小的尺寸，可以合理地预期气候沿沿着走向持续变化。在这里，我们提出了一项研究的结果，探讨如何在最长（106-7年）和最短（102-4年）的时间尺度的提顿景观响应。长期峡谷切口率确定的磷灰石（铀钍）/他（AHe）分析的主要排水系统是最高的（0.24毫米年-1），其中测得的隆起率和持续时间最高（莫兰山附近），导致我们提出，构造强迫作为一阶控制长期提顿侵蚀。短期剥蚀率，这是通过确定沉积在最近的冰期（派恩代尔，~15.5 ka）期间产生的集水区在莫兰湾的沉积物体积，是0.00303 - 0.4672毫米yr-1。我们将这些速率与以前的工作进行比较，发现高岩石下降速率（1.13-1.14 mm yr-1）存款在雪崩和莫兰峡谷中有大量的堆积体。尽管数量巨大，但这种高质量浪费率并不像测量的湖泊沉积物体积（0.007立方公里）那样长期持续。我们的结论是，提顿运输限制在间冰期和大量的峡谷沉积物在此期间产生的不能移动没有山谷冰川的进步。也就是说，在剥蚀的山区地形中，小山系中的河流系统远不如冰川有效。
OF THESIS DETERMINING RATES OF LANDSCAPE RESPONSE TO TECTONIC FORCING ACROSS A RANGE OF TEMPORAL SCALES AND EROSIONAL MECHANISMS: TETON RANGE, WY Understanding how mountain landscapes respond to variations in tectonic forcing over a range of temporal scales in active mountain belts remains as a prominent challenge in tectonic and geomorphological studies. Although a number of empirical and numerical studies have examined this problem, many of them were complicated by issues of scale and climatic variability. More specifically, the relative efficiencies of fluvial and glacial erosion, which are presumably controlled by climate, are difficult to unravel. The Teton Range in Wyoming, which results from motion on the crustal-scale Teton fault, is an ideal natural laboratory for addressing this challenge as the tectonic uplift boundary condition and the variation of uplift along strike is well-documented by previous studies and due to its relatively small size, climate can be reasonably expected to vary consistently along strike. Here, we present the results from a study that examines how the Teton landscape responds across the longest (106-7 yrs) and shortest (102-4 yrs) temporal scales. Long-term canyon incision rates determined from apatite (U-Th)/He (AHe) analysis of major drainages are highest (0.24 mm yr-1) where measured uplift rates and duration are highest (near Mount Moran), leading us to propose that tectonic forcing operates as the first order control on long-term Teton erosion. Short-term denudation rates, which are derived by determining sediment volumes in Moran Bay that are deposited in catchments generated during the most recent glacial interval (Pinedale, ~15.5 ka), are 0.00303 – 0.4672 mm yr-1. We compare these rates to previous work, which found that high rock fall rates (1.13-1.14 mm yr-1) deposit large talus volumes in Avalanche and Moran Canyons. Despite their magnitude, such high rates of mass wasting are not sustained over long periods of time, as measured lake sediment volumes (0.007 km3) are. We conclude that the Tetons are transport limited during the interglacial and large volumes of canyon sediment generated during this time cannot be moved absent the advance of valley glaciers. That is, fluvial systems in small mountain systems are substantially less effective than glaciers in denuding mountain topography.