MORB Construction Processes: Plutonic to Volcanic Connections in Plagioclase Ultraphyric Basalts (PUBs)

洋中脊玄武岩及其相关火山岩的组成是阐明最终导致海洋地壳形成的熔融过程以及全球地球化学循环和板块构造等过程的主要观测数据集之一。然而，大多数MORB被发生在上地幔和海洋地壳中的过程所改变。为了约束MORB在从地幔到洋壳的停留和转移过程中改变其组成的过程，本研究将对来自超慢速和中等扩张速率洋中脊的富含斜长石的MORB进行地球化学和结构研究。工作的重点将是斜长石-超水玄武岩中的斜长石。这种矿物是一种潜在的丰富的、大部分未开发的岩浆温度、组成、质量平衡和时间的记录物。分析工作将包括现场分析化学和同位素分析技术、熔岩主要元素和微量元素组成分析、结构研究、微量元素扩散剖面测定、晶体尺寸分布和其他方法的结合。这项工作更广泛的影响是对学生和早期职业教师的支持。

The compositions of mid ocean ridge basalts (MORBs) and related volcanic rocks are one of the primary observational datasets used to illuminate melting processes that ultimately lead to formation of ocean crust and processes like global geochemical cycling and plate tectonics. Most MORB, however, is modified by processes that occur in the upper mantle and oceanic crust. To constrain the processes that modify the composition of MORB during its residence and transit from the mantle through the oceanic crust, this research will carry out a geochemical and textural study of plagioclase-rich MORB from ultra-slow and intermediate spreading-rate mid ocean ridges. The focus of the work will be on plagioclase from plagioclase-ultraphyric basalts. This mineral is a potentially rich and largely unexploited recorder of magma temperature, composition, mass balance and time. Analytical work will include a combination of in situ analytical chemical and isotopic analysis techniques, analyses of major and trace element compositions of the lavas, textural studies, determination of trace element diffusion profiles, crystal size distributions, and other approaches. Broader impacts of the work are support of a student and an early career faculty member.