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

合作研究：离轴环境中的融化——8*20N海山链的跨学科领域和建模研究，EPR

• 批准号: 1356822
• 负责人: Daniel Fornari
• 金额: $ 13.77万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1356822&HistoricalAwards=false
• 关键词: Collaborative; Research; Melting; Off; Axis; Collaborative; Research; Melting; Off; Axis

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.

了解如何通过上地幔到狭窄的近代山脊（MOR）轴在数百公里上产生和聚焦，这是了解如何形成地球的海洋外壳以及如何在我们的星球内部及其表面之间交换元素和热量的基础。在使用计算机模型来研究地幔熔化和熔体传输方面，已经取得了重大进步。但是，从同一区域缺乏完全的地球物理和地球化学数据是一个关键的信息差距，需要在精炼现有模型中进行进展之前填补。这项研究需要一项多学科地球物理和地球化学计划，以绘制，采样和分析8°20'N封口链的样品，该链从东太平洋上升的Siqueiros ridge ridge-Transform向西延伸200公里。海山提供了一个独特的机会，可以测试熔融分布和源变化的假设，该假设远离扩展中心。建造这些海拔的融化为上幔提供地球化学窗户。该研究包括一次海洋学巡游，以绘制和采样目标区域。接下来是地球物理数据处理和岩石学，岩石学和岩化学分析，对使用Alvin（载人的深层潜水和疏and）收集的样品进行了地球化学分析。该研究的目标是在快速扩张中心开发用于上层岩石圈结构，变形和融化分布的新的集成模型，并研究离轴熔化的动力学。该方法是跨学科的，包括分析地球物理和地球化学数据以及地球动力学建模。还将分析岩石样品的所有主要元素和痕量元素以及ND，SR和PB的放射异位素。该项目的更广泛的影响包括建立针对中学一级的海洋地质课程单元，并符合45个州目前已通过的下一代科学标准。该项目涉及与Pipkin中学的老师和管理人员紧密合作，Pipkin中学是一所全国排名第一的I学校，为密苏里州斯普林菲尔德低收入中心城市的580名学生提供服务（贫困指数为78％）。教师将与研究人员紧密合作，双方将共同创建教育材料。重点将放在学习和将基本科学过程与当前研究联系起来。试点实施将与拟议的现场计划一致。开发的单元将通过现代资源网站的网络广泛提供。