Noble Gases, Lower Mantle Structures, and the Origin of Ocean Island Basalts

柯蒂斯·威廉姆斯博士被授予NSF EAR博士后奖学金，在加州大学戴维斯分校开展一项研究和扩大参与计划。研究人员将确定惰性气体系统学并开发地幔对流模型，以更好地约束地幔热柱源区的形成、位置和保存。洋岛玄武岩代表了起源于下地幔的羽流的表面表现形式；因此，洋岛玄武岩提供了关于地球下地幔化学结构和动力学的有价值的信息。大洋界面惰性气体的研究对于了解地球下地幔的化学成分和结构、了解地球的吸积、随后的分化和脱气以及大气的形成至关重要。威廉姆斯博士将为培训下一代地球科学家做出贡献，他将成为榜样，并吸引来自代表性不足群体的学生。这项研究将利用大洋界面的惰性气体系统学来：[1]约束下地幔原始稀有气体的来源区；[2]记录富集型地幔组分的重惰性气体特征，并了解由稀有气体确定的不同组分之间的成因关系；[3)利用地幔对流动力学模型来了解化学不均一性的保存以及下地幔致密基层的夹带程度是否与地幔热柱中的地球化学观测相一致。

Dr. Curtis Williams has been awarded an NSF EAR Postdoctoral fellowship to carry out a research and broadening participation plan at the University of California - Davis. The investigator will determine noble gas systematics and develop models of mantle convection to better constrain the formation, location, and preservation of the source region for mantle plumes. Ocean island basalts (OIBs) represent the surface manifestation of plumes that originate in the lower mantle; as such, OIBs provide valuable information regarding chemical structure and dynamics of Earth's lower mantle. The study of noble gases in OIBs is crucial to the understanding of the chemical composition and structure of Earth's lower mantle, the understanding of Earth's accretion, its subsequent differentiation and degassing, and the formation of the atmosphere. Dr. Williams will contribute to the training of the next generation of Earth scientists by being a role model and engaging students from under-represented groups. This investigation will use noble gas systematics of OIBs to: [1] constrain the source region of the primitive noble gases in the lower mantle; [2] document the heavy noble gas signature of enriched mantle components and understand the genetic relationship between the different components as determined from the noble gases; [3] use dynamic models of mantle convection to understand the preservation of chemical heterogeneities and whether the degree of entrainment of a dense basal layer in the lower mantle is consistent with geochemical observations in mantle plumes.