CAREER: Developing New Methodologies to Investigate the Thermal, Tectonic, and Climatic History of Continental Settings - An Integrated Educational and Research Project

职业：开发新方法来研究大陆环境的热、构造和气候历史 - 一个综合教育和研究项目

• 批准号: 0545071
• 负责人: M. Clara Castro
• 金额: $ 45.11万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0545071&HistoricalAwards=false
• 关键词: CAREER; Developing; New; Methodologies; Investigate

For over two decades it has been assumed that transport properties for both heat and helium are similar in the crust and that transport for both tracers is in steady-state. In addition, the presence of a terrestrial helium-heat imbalance was suggested based on the observed low mantle He/heat flux ratio at the proximity of mid-ocean ridges. Recent work, however, indicates that the driving transport mechanisms for these two tracers are of a fundamentally different nature for a high range of rock permeabilities in the crust. It was concluded that low He/heat flux ratios in a steady-state regime do not reflect a He deficit in the crust or mantle original reservoirs, but rather, the combined impact of air saturated water, advection, conduction, and diffusion. Together with other noble gas measurements and determined noble gas temperatures (NGTs), part I of the proposed work will take advantage of these recent findings to test and develop the newly created He/heat flux tracer to identify the occurrence, both in time and space, of tectonothermal events in continental regions, and in the Michigan Basin in particular. Part II will take advantage of common tools in order to address questions in relation to NGT determination in ice-covered regions. The latter is a direct measure of the temperature at which groundwater equilibrated with the atmosphere during infiltration and offer a unique opportunity to improve our understanding of past climate in continental areas as well as to assess the impact of glaciation on groundwater recharge in mid-high latitude regions. In addition to illustrating how He/heat flux ratios can be used in conjunction with NGTs to investigate the tectonothermal history of continental regions, this work will also contribute to an improved understanding of NGT determination in ice-covered regions. This work will impact knowledge in the fields of Mantle Geochemistry, Geophysics, Structural Geology, Hydrology and Paleoclimatology.This research will be the basis of a new, exclusively research-oriented undergraduate course. Identifying problems to be addressed, collecting and analyzing data, testing hypotheses, reaching potential conclusions and writing the prototype of a scientific paper will be an integral part of this class. Of particular relevance is the participation of undergraduate non-science majors, in particular women and underrepresented groups into scientific discovery, which is expected to captivate students and ultimately draw increasing numbers into a scientific career.

二十多年来，人们一直认为热量和氦在地壳中的传输特性是相似的，并且两种示踪剂的传输都处于稳态。此外，根据在大洋中脊附近观测到的低地幔氦/热通量比，提出了陆地氦热不平衡的存在。然而，最近的工作表明，这两种示踪剂的驱动传输机制是一个根本不同的性质为高范围的岩石渗透率在地壳中。得出的结论是，低的He/热通量比在稳态制度不反映他赤字在地壳或地幔原始水库，而是，空气饱和水，平流，传导和扩散的综合影响。连同其他惰性气体测量和确定的惰性气体温度（NGTs），拟议工作的第一部分将利用这些最新的发现来测试和开发新创建的He/热通量示踪剂，以确定大陆地区，特别是密歇根盆地的构造活动在时间和空间上的发生。第二部分将利用共同的工具，以解决有关的问题NGT确定在冰雪覆盖的地区。后者是一个直接测量的温度时，地下水与大气在渗透过程中达到平衡，并提供了一个独特的机会，以提高我们对过去的气候在大陆地区的理解，以及评估冰川作用对地下水补给的影响在中高纬度地区。 除了说明如何他/热通量比可以与NGTs一起使用，以调查大陆地区的构造历史，这项工作也将有助于更好地了解NGT确定在冰覆盖的地区。这项工作将影响地幔地球化学，地球物理学，结构地质学，水文学和古气候学领域的知识。这项研究将是一个新的，完全以研究为导向的本科课程的基础。确定要解决的问题，收集和分析数据，测试假设，得出潜在的结论和撰写科学论文的原型将是本课程不可或缺的一部分。特别重要的是，非理科专业的本科生，特别是妇女和代表性不足的群体参与科学发现，预计这将吸引学生，并最终吸引越来越多的人从事科学职业。