| 项目编号: | 1463709
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| 项目名称: | EAGER: Cosmogenic Nuclide Measurement of Surface Uplift Rate and Paleoelevation |
| 作者: | Gregory Hoke
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| 承担单位: | Syracuse University
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| 批准年: | 2014
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| 开始日期: | 2015-01-15
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| 结束日期: | 2016-12-31
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| 资助金额: | USD147053
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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 - Earth Sciences
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| 英文关键词: | uplift rate
; paleoelevation
; method
; uplift
; elevation
; surface elevation
; terrestrial cosmogenic nuclide
; independent surface age constraint
; production rate
; erosion rate
; uplifting surface
; uncertainty
; cosmogenic nuclide
; sample
; different rate
; stable surface
; earth?s surface
; surface uplift datum
; identical surface
; cosmogenic nuclide production
; precise measurement
; tcn production rate
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| 英文摘要: | Understanding the tectonic forces that drive uplift of large continental plateaus and mountain belts depends on measurement of how fast the surfaces in those physiographic domains have been uplifted and, consequently, how surface elevation has changed with time. Different models of uplift predict different rates or past elevations. Various methods have been used to measure uplift rates and paleoelevation to varying success and with varying degrees of uncertainty. In this project, the research team aims to test a new and novel technique that has the potential to reduce these uncertainties, which could potentially better constrain the understanding of the fundamental forces operating within the Earth that generate these major features. The method relies on precise measurement of cosmogenic nuclides, which are produced in minerals during exposure to cosmic rays. This exploratory project relies on the dependence of cosmogenic nuclide production on elevation to determine uplift rates and paleoelevation in a test on samples from a well-constrained field setting in South America. The engagement of a post-doctoral fellow in the project promotes development of the STEM workforce.
This exploratory project develops of a new measure of surface uplift rate using terrestrial cosmogenic nuclides (TCN). Because the method measures uplift rate over a defined timescale, it also yields paleoelevation. The method exploits the well-established dependence of TCN production rates on elevation. The premise is that a stable surface will always have a higher TCN concentration than an otherwise identical surface that has been recently uplifted to the same elevation. Uplifting surfaces exhibit this deficit because most TCN production occurred at a lower elevation - and therefore lower production rate. The size of the deficit depends on the uplift rate and duration of production. The method solves for both erosion rate and surface uplift rate simultaneously over a defined time interval by using multiple samples and multiple isotope pairs, along with independent surface age constraints, in order to gain precision. In order to assess the precision and applicability of this technique, the research team will sample and measure TCN concentrations (21Ne, 10Be, and 26Al) for Miocene to Pliocene ignimbrites of the Atacama Desert (Chile and Peru), where independently determined surface uplift data are available to verify TCN results. The goal is to understand (1) how the method performs at a range of uplift rates; (2) how increasing the number of samples may reduce uncertainty; and (3) whether the approach is internally consistent over different timescales and using different isotope pairs. The research would enhance post-doctoral training thus contributing to the development of a globally competitive STEM workforce and involve the significant international collaboration with the GeoForschungsZentrum in Potsdam, Germany. A successful outcome will be a new novel paleoaltimetry tool that will be widely applicable over much or the Earth?s surface and will transform the ability to determine paleoelevation and surface uplift rates in active orogens or areas experiencing uplift due to dynamic topography or glacial isostatic adjustment. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/95204
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Gregory Hoke. EAGER: Cosmogenic Nuclide Measurement of Surface Uplift Rate and Paleoelevation. 2014-01-01.
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