EAR-PF: An Experimental Investigation of the Rheological Behavior and Seismic Anisotropy Signature of Deep Crustal Amphibole-Rich Rocks

EAR-PF：深地壳富含角闪石岩石的流变行为和地震各向异性特征的实验研究

• 批准号: 1725633
• 负责人: Cailey Condit
• 金额: $ 8.7万
• 依托单位: Condit Cailey B
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1725633&HistoricalAwards=false
• 关键词: EAR; PF; Experimental; Investigation; Rheological

Dr. Cailey Condit has been granted an NSF EAR postdoctoral fellowship to carry out research and educational plans at the Massachusetts Institute of Technology. She will investigate the way amphibole, a common but poorly understood mineral within the earth's crust, behaves when it is deformed under high temperatures and pressures. This work will directly augment our understating of continuous deformation within ductile shear zones in the deep crust, where rocks flow rather than break, and within subduction zones, where oceanic crust is descending beneath continents. This experimental work is aimed at constraining the strength of these highly deformed, amphibole-rich zones and investigating their geophysical properties so that geophysicists can make more accurate inferences about amphibole-rich rocks from remote observations of the deep crust. By shedding new light on the strength and deformation behavior of amphibole, these data allow us to better predict how continuous deformation may influence the mechanics within zones of earthquake production. The education plan involves Dr. Condit (1) co-teaching a graduate-undergraduate seminar in rock deformation at MIT, (2) acting as a research mentor for several undergraduate researchers, (3) continuing and expanding her geologic outreach on social media, and (4) making geologic presentations at assisted living facilities to disseminate geologic knowledge across generations. Dr. Condit will utilize the state-of-the-art facilities at MIT's rock deformation laboratory to conduct a series of experiments on amphibole, deforming samples at a range of temperatures, pressures, and strain rates representative of those found in the middle to lower crust. With these experimental results, she will determine the deformation mechanisms of amphibole and its rheology under deep crustal conditions. She will then directly tie her observations of these experimentally deformed rocks to naturally deformed amphibole, and collect seismic anisotropy data from the experimentally deformed amphibole samples. This will allow for a direct comparison between deformation mechanism, rock strength, and seismic anisotropy signals produced by the deformed amphibole. These insights will allow geophysicists to better link their remotely sensed observations of seismic anisotropy with the amphibole-rich rocks that produce those signals in the deep crust. Geologists working on naturally deformed amphibole-rich rocks will also be able to use these data to constrain the strength and deformation mechanisms of their rocks.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Cailey Condit博士已获得NSF博士后奖学金，在马萨诸塞州理工学院开展研究和教育计划。她将研究角闪石，一种常见但知之甚少的地壳矿物，在高温高压下变形时的行为。这项工作将直接增加我们对地壳深部韧性剪切带内连续变形的理解，在那里岩石流动而不是破裂，以及俯冲带内，海洋地壳下降到大陆之下。这项实验工作旨在限制这些高度变形的富含角闪石的区域的强度，并调查其地球物理性质，以便地球物理学家可以通过对地壳深部的远程观测对富含角闪石的岩石进行更准确的推断。通过对角闪石的强度和变形行为进行新的研究，这些数据使我们能够更好地预测连续变形如何影响地震产生区域内的力学。康迪特（1）在麻省理工学院共同教授岩石变形的研究生-本科生研讨会，（2）担任几位本科生研究人员的研究导师，（3）继续并扩大她在社交媒体上的地质推广，以及（4）在辅助生活设施中进行地质演示，以跨代传播地质知识。Condit博士将利用麻省理工学院岩石变形实验室的最先进的设施，对角闪石进行一系列实验，在一定范围的温度，压力和应变率下对样品进行变形，这些应变率代表了中下地壳中发现的样品。利用这些实验结果，她将确定角闪石的变形机制及其在地壳深部条件下的流变性。然后，她将直接将她对这些实验变形岩石的观察与自然变形的角闪石联系起来，并从实验变形的角闪石样品中收集地震各向异性数据。这将允许变形机制，岩石强度和地震各向异性信号之间的直接比较变形角闪石产生的。这些见解将使地震学家能够更好地将他们对地震各向异性的遥感观测与在地壳深部产生这些信号的富含角闪石的岩石联系起来。研究自然变形的富含角闪石的岩石的地质学家也将能够使用这些数据来约束岩石的强度和变形机制。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。