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

凯利·康迪特博士获得了NSF EAR博士后奖学金，在麻省理工学院开展研究和教育计划。她将研究角闪石是地壳中一种常见但鲜为人知的矿物，当它在高温和压力下变形时，它的行为方式。这项工作将直接加强我们对深部地壳韧性剪切带内持续变形的轻描淡写，在那里岩石流动而不是破裂，在俯冲带内，洋壳下降到大陆以下。这项实验工作的目的是限制这些高度变形的富角闪带的强度，并研究它们的地球物理性质，以便地球物理学家可以通过对地壳深部的远程观测来对富角闪岩做出更准确的推断。通过揭示角闪石的强度和变形行为，这些数据使我们能够更好地预测持续变形如何影响地震孕育区内的力学行为。康迪特博士的教育计划包括：(1)共同教授麻省理工学院岩石变形方面的研究生-本科生研讨会，(2)担任几名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学宣传，以及(4)在辅助生活设施做地质学演讲，以便将地质学知识传播给几代人。康迪特博士将利用麻省理工学院岩石变形实验室的最先进设备对角闪石进行一系列实验，在代表中到下地壳中发现的温度、压力和应变率的范围内使样品变形。根据这些实验结果，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的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本中收集地震各向异性数据。这将允许直接比较变形的角闪石产生的变形机制、岩石强度和地震各向异性信号。这些洞察力将使地球物理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处产生这些信号的富含角闪石的岩石联系起来。致力于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他们岩石的强度和变形机制。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.