What are the Parental Magma Compositions for Historical Kilauea Lavas?

位于夏威夷岛上的基拉韦厄火山是世界上最活跃、监测最好的火山之一。先前的野外、岩石学、地球化学和地球物理研究已经建立了基拉韦厄岩浆管道系统的基本结构，使其被称为“世界上最好理解的玄武岩火山”。这使得基拉韦厄成为解决岩浆如何在玄武岩火山中形成的基本问题的理想场所。 对基拉韦厄熔岩化学中长期和短期地球化学波动背后的物理机制知之甚少。 为什么火山在不同的时间尺度上表现出独特的地球化学变化？ 是什么过程导致了地球化学时间趋势轨迹的变化？ “共同”趋势的起源是什么？ 我们的假设是，基拉韦厄火山熔岩化学的短期和长期变化反映了夏威夷地幔柱内部熔体生成、提取和输送的动力学。这项为期四年的研究成果将包括对当前喷发熔岩的岩相学、矿物化学、全岩主要元素和微量元素丰度以及Pb、Sr、Nd和U系列同位素比值的新分析，在Uwekahuna海崖暴露的史前山顶熔岩、选定的裂谷带熔岩以及来自这些和其他富含橄榄石的玄武岩的橄榄石熔融包裹体。这些数据将用于确定基拉韦厄熔岩成分变化的地幔原因，例如，源的变化与熔化量的变化。这些过程控制着火山的喷发速度，因此我们的工作将对预测未来火山喷发的持续时间产生影响。 这项研究的更广泛的影响包括指导研究生和本科生，在大学教授火山学，岩石学和地球化学课程，使用我们研究中的例子，让代表性不足的学生参与我们的研究，为学校团体和当地社区举办公开讲座，更好地了解可能对生活质量产生负面影响的火山，通过协作和利用多用户设施，加强国际和国家科学合作。

Kilauea Volcano, on the Island of Hawaii, is one of the most active and best monitored volcanoes in the world. Previous field, petrologic, geochemical and geophysical studies have established the basic structure of Kilauea's magmatic plumbing system, leading it to be called "the best understood basaltic volcano in the world". This makes Kilauea an ideal venue for addressing fundamental questions about how magma is formed in basaltic volcanoes. The physical mechanisms behind the long-term and short-term geochemical fluctuations in lavas chemistry at Kilauea are poorly understood. Why does the volcano exhibit distinctive geochemical variations over different time scales? What process caused the change in the trajectory of the temporal geochemical trends? What is the origin of the "common" trend? Our hypothesis is that the short-term and long-term variations in lava chemistry at Kilauea reflect the dynamics of melt generation, extraction and transport within the heterogeneous Hawaiian mantle plume.The outcomes for this four year study will include new analyses of the petrography, mineral chemistry, whole-rock major element and trace element abundances, and Pb, Sr, Nd and U-series isotope ratios for lavas from the current eruption, prehistoric summit lavas exposed in Uwekahuna Bluff, selected rift zone lavas, and olivine-hosted melt inclusions from these and other olivine-rich basalts. These data will be used to determine the mantle causes for compositional variation in the Kilauea lavas, for example, source variations vs. changes in the amount of melting. These processes control the eruption rate of volcanoes, so our work will have implications for predicting the duration of future eruptions. The broader impacts of this research include mentoring graduate and undergraduate students, teaching volcanology, petrology and geochemistry courses at universities with a large population of underrepresented students using examples from our research, involving underrepresented students in our research, giving public lectures to school groups and the local community, gaining a better understanding of volcanoes that can negatively influence the quality of life, and increasing international and national scientific cooperation through collaboration and utilization of multi-user facilities.