Collaborative Research: Characterizing and Modeling Crustal Recycling

合作研究：地壳回收的表征和建模

• 批准号: 1551054
• 负责人: Bradley Hacker
• 金额: $ 33.28万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-15 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1551054&HistoricalAwards=false
• 关键词: Collaborative; Research; Characterizing; Modeling; Crustal

Recycling of Earth's crust back down into the deep Earth has been invoked to explain a wide variety of Earth processes, including changes in the forces that move tectonic plates, and how the thickness and composition of Earth's crust evolved. All of these processes take place at depths inaccessible to humans. A volcanic eruption in the Pamir Mountains of Tajikistan has brought to light pieces of rock from 90 km deep in Earth that can be used to test recycling-related hypotheses. This project will provide training and research opportunities for graduate student Madeline Shaffer and several undergraduate students. Visits to local elementary schools will expose potential future scientists to Earth science. Continued development of the laser-ablation split-stream technique will benefit the broad range of visitors to their laboratory.This collaborative US-Tajik-Romanian project has a two-pronged approach: 1) Laboratory geochronology and petrology that will constrain the timescale of recycling, and the compositions, densities and wavespeeds of the recycling materials. With some assumptions about protolith composition, the evolution in these physical properties can be calculated. 2) Geodynamic modeling of recycling crustal sections with different compositions and layers in different thermal gradients. The models will yield the calculated evolution of the physical properties of recycling crust and determine the types of crustal sections that may recycle. Because the Pamir-Tibetan Plateau is an archetypal continent-continent collision, ideas developed there can be applied globally.

地壳循环回到地球深处已被用来解释各种各样的地球过程，包括移动构造板块的力的变化，以及地壳的厚度和成分如何演化。所有这些过程都发生在人类无法到达的深处。塔吉克斯坦帕米尔山脉的一次火山喷发揭示了地球深处 90 公里处的岩石碎片，可用于测试与回收相关的假设。该项目将为研究生 Madeline Shaffer 和几名本科生提供培训和研究机会。参观当地小学将使未来潜在的科学家接触地球科学。激光烧蚀分流技术的持续发展将使实验室的广泛参观者受益。这个美国-塔吉克斯坦-罗马尼亚合作项目有两个管脚的方法：1）实验室地质年代学和岩石学将限制回收的时间尺度，以及回收材料的成分、密度和波速。通过对原岩成分的一些假设，可以计算这些物理特性的演变。 2）不同温度梯度下不同成分、不同层位的循环地壳剖面的地球动力学模拟。这些模型将计算出再循环地壳物理性质的演变，并确定可能再循环的地壳部分的类型。由于帕米尔高原是典型的大陆与大陆碰撞的地区，因此在那里提出的想法可以在全球范围内应用。