Collaborative Research: Experimental Determination of Trace Element Partition Coefficients Between Anorthitic Plagioclase and MORB

本研究对高温斜长石晶体在地壳压力和含水量下进行了一组详细的实验，以便对岩浆过程的数值模型进行校准。这项工作的重要性在于，长石晶体的分带模式与树木年轮相似，因为这些区域通常是同心的，记录了矿物生长过程中随时间发生的化学变化，在这种情况下，记录了它们生长的岩浆的组成、温度和压力的变化。因此，这些矿物可以揭示有关地幔中熔融量、岩浆结晶、岩浆停留时间、岩浆体与下地壳的相互作用以及从地幔到地壳的质量和热量传递量的信息。简而言之，地球的热机是如何工作的。目前，人们还不清楚元素是如何根据温度、压力和组成（包括这些矿物质中的水）的变化而分布的。这项资助的研究旨在研究在0.7 GPa的压力下，在重量为0 - 1.5%的H2O存在下，钙长石斜长石中Li， Ba, Sr, Pb， Zr和稀土元素的分带。设计实验的具体目标是了解形成海洋地壳的岩浆过程，特别是与缓慢和中等扩张中心和断裂带有关的岩浆过程。数据将被纳入热力学数据库，用于模拟熔体成分和演化。这项工作的更广泛影响包括研究生培训和构建构成科学基础设施的基本数据集。

This research carries out a set of detailed experiments on high temperature plagioclase crystals at crustal pressures and water contents to allow calibration of numerical models of magmatic processes. The importance of this work is that the zoning patterns of feldspar crystals are similar to tree rings in that the zones are often concentric and record the chemical changes that have occurred over time during the growth of the mineral, in this case recording changes in the composition, temperature, and pressure of magmas in which they grew. As such, these minerals can reveal information on the amount of melting in the mantle, the crystallization of a magma, magma residence times, the interaction of magma bodies with the lower crust, and the amount of mass and heat transfer from the mantle to the crust. In short, how the Earth's heat engine works. At present, it is not clear how elements distribute themselves as a function of temperature, pressure, and composition, including H2O in these minerals. The funded research is designed to examine the zoning of Li, Ba, Sr, Pb, Zr and rare earth elements in anorthite plagioclase at pressures to 0.7 GPa in the presence of 0 to 1.5 weight percent H2O. Experiments have been designed with the specific goal of understanding magmatic processes that create the ocean crust, in particular, that associated with slow and intermediate spreading centers and fracture zones. Data will be incorporated into thermodynamic databases for modeling melt composition and evolution. Broader impacts of the work include graduate student training and building essential datasets that make up the infrastructure for science.