CAREER: Modeling two-phase flow, multi-lithologic melting, and chemical disequilibrium with uranium-series isotopes

该项目旨在使用计算机模型来探索岩浆的起源，这些模型可以预测熔岩的化学组成，特别是保存地球地幔中熔化速度和岩浆运输信息的同位素。该项目测试了不同的地幔岩石类型在岩浆形成中的作用，以及在岩浆运输过程中化学扩散的重要性。有关岩浆起源的问题对于我们理解动态的全球过程和板块构造，包括火山喷发产生的新洋壳的起源，是至关重要的。该项目还旨在开发一个设在内布拉斯加州大学的计算机建模方案，以培训下一代地球科学计算机建模人员，并通过更广泛的外联活动，提高公众对STEM的参与和识字能力。模拟技术和教程将在一个开源代码库和教育库中在线托管和管理。回收的地幔岩性在地幔熔融和玄武岩形成中的作用和重要性，以及缓慢的化学扩散对多岩性部分熔融的影响仍不清楚。熔岩中铀系不平衡可能为识别岩性物源非均质性提供了一种方法，但U系列模拟仍然复杂且难以复制。这项研究的总体研究目标是通过开发预测玄武岩中U系列不平衡的新的开源建模程序包来测试多岩性熔融和扩散交换，并通过将现有的U系列数据与对熔融区域中辉石岩存在敏感的测量结果进行比较来验证建模工作的真实性。教育目标是将建模工作纳入现有和新的地球科学课程的课程中，并创建和策划数字课程和培训教程，并通过在线计划分享它们。这项工作的基本原理是促进对地幔熔融过程的理解，培训未来一批复杂的地学建模人员，并开发可广泛使用和可重复使用的熔融模拟工具，这些工具可以整合到社区研究和教学工作中。该项目的成果将通过开发存档的、开源的、云托管的建模代码包来扩大。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to explore the origins of magmas using computer models that predict the chemical makeup of lavas, particularly for isotopes that preserve information about rates of melting and magma transport in the Earth’s mantle layer. The project tests for the role of alternative mantle rock types in generating magma, and for the importance of chemical diffusion during magma transport. Questions about magma origins are fundamentally important to our understanding of dynamic global processes and plate tectonics, including the origins of new oceanic crust produced by volcanic eruptions. The project further aims to develop a computer modeling program housed at the University of Nebraska to train the next generation of geoscience computer modelers, and to increase public engagement and literacy with STEM through broader outreach. Modeling techniques and tutorials will be hosted and managed online in an open-source code repository and educational library.The roles and importance of recycled mantle lithologies in mantle melting and basalt generation and of the influence of slow chemical diffusion on multi-lithologic partial melting remain unclear. Uranium-series disequilibria in lavas may provide a method for identifying lithologic source heterogeneity, but U-series modeling remains complex and difficult to replicate. The overall research goal of this study is to test multi-lithologic melting and diffusive exchange through the development of new, open-source modeling packages that predict U-series disequilibria in basalts, and to ground-truth that modeling effort by comparison of existing U-series data with measurements sensitive to the presence of pyroxenite in the melting regime. The educational goals are to incorporate the modeling work into lessons for existing and new geoscience courses and to create and curate digital lessons and training tutorials and share them via an online program. The rationales for this work are to advance the understanding of mantle melting processes, train a future cohort of sophisticated geoscience modelers, and develop widely-accessible and reproducible melt modeling tools that can be integrated into community research and teaching efforts. The outcomes of the project will be amplified through the development of archived, open-source, cloud-hosted modeling code packages.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.