EAGER: Cosmogenic Nuclide Measurement of Surface Uplift Rate and Paleoelevation

GSTDTAP

项目编号	1463709
	EAGER: Cosmogenic Nuclide Measurement of Surface Uplift Rate and Paleoelevation
	Gregory Hoke
主持机构	Syracuse University
项目开始年	2015
	2015-01-15
项目结束日期	2015-12-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	147053(USD)
国家	美国
语种	英语
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.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/67487
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Gregory Hoke.EAGER: Cosmogenic Nuclide Measurement of Surface Uplift Rate and Paleoelevation.2015.