| 项目编号: | 1543256
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| 项目名称: | Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry |
| 作者: | David Shuster
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| 承担单位: | Berkeley Geochronology Center
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| 批准年: | 2016
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| 开始日期: | 2016-06-01
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| 结束日期: | 2019-05-31
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| 资助金额: | 366898
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Polar
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| 英文关键词: | antarctic peninsula
; glacial erosion
; development
; timing
; alpine landscape
; peninsula
; u-th
; landscape
; exhumation history
; low-temperature thermochronometry
; topography development
; ice
; glacial landscape
; high-relief landscape
|
| 英文摘要: | The extreme mountain topographies of alpine landscapes at mid latitudes (e.g., European Alps, Patagonia, Alaska) are thought to have formed by the erosive action of glaciers, yet our understanding of exactly when and how those topographies developed is limited. If glacial ice was responsible for forming them, then those landscapes must have developed primarily over the last 2-3 million years when ice was present at those latitudes; this timing has only recently been confirmed by observations. In contrast, the Antarctic Peninsula, which contains similarly spectacular topographic relief, is known to have hosted alpine glaciers as early as 37 million years ago, and is currently covered by ice. Thus, if caused by glacial erosion, the high relief of the peninsula should have formed much earlier than what has been observed at mid latitude sites, yet we know nearly nothing about the timing of its development. The primary benefit of this research will be to study the timing of topography development along the Antarctic Peninsula by applying state of the art chemical analyses to sediments collected offshore. This research is important because studying a high latitude site will enable comparison with sites at mid latitudes and test current hypotheses on the development of glacial landscapes in general.
This project aims to apply low-temperature thermochronometry based on the (U-Th)/He system in apatite to investigate the exhumation history, the development of the present topography, and the pattern of glacial erosion in the central Antarctic Peninsula. A number of recent studies have used this approach to study the dramatic, high-relief landscapes formed by Pleistocene alpine glacial erosion in temperate latitudes: New Zealand, the Alps, British Columbia, Alaska, and Patagonia. These studies have not only revealed when these landscapes formed, but have also provided new insights into the physical mechanisms of glacial erosion. The Antarctic Peninsula is broadly akin to temperate alpine landscapes in that the dominant landforms are massive glacial troughs. However, what we know about Antarctic glacial history suggests that the timing and history of glacial erosion was most likely very different from the temperate alpine setting: The Antarctic Peninsula has been glaciated since the Eocene, and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. Our goal is to evaluate these hypotheses by developing a direct thermochronometric record of when and how the present glacial valley relief formed. We propose to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. In effect, since we cannot sample bedrock directly that is currently covered by ice, we will rely on these glaciers to do it for us. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/92100
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
David Shuster. Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry. 2016-01-01.
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