Collaborative Research: Melting in the Off-Axis Environment - Interdisciplinary Field and Modeling Studies of the 8 20'N Seamount Chain, EPR

了解熔体是如何产生的，并在数百公里的范围内通过上地幔集中到狭窄的大洋中脊（MOR）轴，这是了解地球海洋地壳是如何形成的，以及地球内部和表面之间元素和热量是如何交换的基础。在利用计算机模型研究地幔熔融和熔体输送方面取得了重大进展。然而，缺乏来自同一地区的互补的地球物理和地球化学数据是一个关键的信息缺口，需要在改进现有模式方面取得进展之前加以填补。这项研究需要一个多学科的地球物理和地球化学项目来绘制、采样和分析来自8°20'N海山链的样本，该海山链从东太平洋隆起向西延伸200公里，位于太平洋的Siqueiros山脊转换交汇处。海山提供了一个独特的机会来检验关于熔体分布和源变化的假设，这些假设发生在远离扩散中心的地方。形成这些海底山的熔体为研究上地幔提供了地球化学窗口。这项研究包括一次海洋学巡航，对目标区域进行测绘和取样。随后将进行地球物理数据处理和岩石学、岩石学和地球化学分析，这些样品是由ALVIN载人深潜器和疏浚器收集的。研究的目标是建立快速扩张中心的上部岩石圈结构、变形和熔体分布的新的综合模型，并研究离轴融化的动力学。该方法是跨学科的，包括地球物理和地球化学数据分析以及地球动力学建模。将分析岩石样品的所有主要和微量元素以及Nd， Sr和Pb的放射性同位素。该项目的更广泛影响包括创建一个针对中学水平的海洋地质学课程单元，并符合目前已被45个州采用的“下一代科学标准”。该项目涉及与Pipkin中学的教师和管理人员密切合作，这是一所全国排名第一的学校，为密苏里州斯普林菲尔德低收入中心城市（贫困指数为78%）的580名学生提供服务。教师将与研究人员密切合作，共同创作教材。重点将放在研究性学习和连接基础科学过程与当前的研究。试点实施将与拟议的实地方案同时进行。开发的单元将通过课程资源网站广泛提供。

Understanding how melts are generated and focused across hundreds of kilometers through the upper mantle to the narrow mid-ocean ridge (MOR) axis is fundamental to understanding how Earth's ocean crust is formed and how elements and heat are exchanged between the interior of our planet and its surface. Significant advancements have been made in the use of computer models to investigate mantle melting and melt transport. However, the lack of complementary geophysical and geochemical data from the same area is a critical information gap that needs to be filled before progress can be made in refining present models. This research entails a multidisciplinary geophysical and geochemical program to map, sample, and analyze samples from the 8°20'N Seamount Chain that extends 200 km westward from the East Pacific Rise Siqueiros ridge-transform intersection in the Pacific Ocean. Seamounts provide a unique opportunity to test hypotheses of melt distribution and source variation that occur away from spreading centers. Melts that build these seamounts provide geochemical windows into the upper mantle. The research includes an oceanographic cruise to map and sample the targeted region. This will be followed by geophysical data processing and petrographic, petrologic, and geochemical analyses of samples collected by both using ALVIN, a manned deep submersible, and dredging. Goals of the research are to develop new, integrated models for upper lithosphere structure, deformation, and melt distribution at a fast-spreading center and investigate the dynamics of off-axis melting. The approach is interdisciplinary and includes analysis of geophysical and geochemical data and geodynamic modeling. Rock samples will be analyzed for all major and trace elements and radiogenic isotopes of Nd, Sr, and Pb will also be analyzed. Broader impacts of the project include creation of a marine geology curricular unit targeted at the middle school level and compliant with Next Generation Sciences Standards that have currently been adopted by 45 states. The project involves working closely with teachers and administrators of Pipkin Middle School, a nationally ranked Title I school that serves 580 students in the low-income center-city of Springfield, MO (poverty index of 78%). The teachers will work closely with the reserachers and both parties will jointly create the educational materials. Emphasis will be placed on inquiry learning and connecting fundamental science processes with current research. The pilot implementation will coincide with the proposed field program. The developed unit will be made broadly available via the web on curricular resource sites.