Silicic melt evolution in the early Izu-Bonin arc recorded in detrital zircons

了解构造板块在地球表面的运动，以及这些板块最终回到地球内部，是我们了解地球及其自然灾害（如地震、海啸和火山爆发）的核心。这项研究的重点是了解火山的形成、生长和最终消亡，这些火山标志着地壳板块回到地球内部的俯冲过程。国际海洋发现项目将对从西太平洋海底深处回收的矿物进行研究，以破译一个不断演变的俯冲带上方火山生长的历史。这项研究的目的是利用这些被称为锆石的矿物的化学性质，更好地了解火山的生命周期，尤其是火山爆发的时间。这项研究将研究和教育紧密结合起来，让本科生参与实验室和实地研究项目，研究目前暴露在美国西部内华达山脉陆地上的类似海底火山系统。本研究的目的是通过寻找硅酸火山作用与调性弧深部成矿作用之间的岩石学联系，更好地了解新形成的洋内火山弧中硅酸熔体的生成过程，并以此来更好地了解相关岩浆作用的时间演化。研究的主要目的是测试岩心中的碎屑锆石是否（或在多大程度上）记录了岩浆锆石结晶的硅熔体的区域和/或长期变化，这些岩心是由国际海洋钻探计划远征351号和其他遗留的海洋钻探岩心从相对原始的海洋弧环境中获得的。锆石的年代学和微量元素地球化学将使弧源碎屑锆石记录的热化学和熔体化学演化与同时期弧斑岩疏浚样本中发现的火成岩锆石记录的热化学和熔体化学演化进行比较。该研究还将生成一个内部一致的来自海相弧组成范围的弧源锆石地球化学参数数据库，这将有助于比较锆石物源研究，因为这些研究将更普遍地包括关键的地球化学物源指标。

Understanding the movement of tectonic plates across Earth's surface and the eventual return of these plates to the interior of our planet is central to our knowledge of Earth and its natural hazards such as earthquakes, tsunamis, and volcanic eruptions. This research focuses on understanding the formation, growth and eventual demise of volcanoes that mark the process of subduction, where tectonic plates return to Earth's interior. Minerals recovered from deep beneath the western Pacific Ocean floor by the International Ocean Discovery Program will be examined to decipher the history of volcano growth above an evolving subduction zone. The goals of the research are to use the chemistry of these minerals, called zircons, to better understand the life cycle of volcanoes, especially the timing of explosive volcanic eruptions. This research involves strong integration of research and education by involving undergraduate university students both in the laboratory and in field-based research projects at similar ocean floor volcanic systems that are now exposed on land in the Sierra Nevada mountains in the western United States. The goal of this study is to better understand the generation of silicic melts in a new and evolving intra-oceanic volcanic arc by searching for petrologic links between silicic volcanism and tonalitic arc plutonism and using this to better understand the evolution of the related magmatic processes through time. The primary goal of the research is to test whether (or to what extent) detrital zircons in drill cores, recovered by the International Ocean Drilling Program Expedition 351 and other legacy ocean drilling cores from a relatively primitive oceanic arc setting, record the regional and/or secular variation in silicic melts that crystallized magmatic zircon. Geochronology and trace element geochemistry of the zircons will allow comparisons between the thermal and melt chemical evolution recorded by arc-derived detrital zircons and by igneous zircons recovered in dredge samples of contemporaneous arc tonalite. This study will also generate an internally-consistent database of geochemical parameters for arc-derived zircons from a compositional range of marine arcs that will be useful for comparative zircon provenance studies, as these studies evolve to more commonly include key geochemical provenance indicators.