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: 1357150
• 负责人: Michael Perfit
• 金额: $ 15.5万
• 依托单位: University of Florida
• 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 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357150&HistoricalAwards=false
• 关键词: 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.

了解融化是如何产生的，并集中在数百公里的上地幔到狭窄的洋中脊（莫尔）轴是了解地球洋壳如何形成以及元素和热量如何在我们的星球内部和表面之间交换的基础。在利用计算机模型研究地幔熔融和熔体输运方面取得了重大进展。然而，缺乏来自同一地区的地球物理和地球化学补充数据是一个重要的信息空白，在完善现有模型方面取得进展之前，需要填补这一空白。这项研究需要一个多学科的地球物理和地球化学计划，以绘制，采样和分析来自8° 20 'N海山链的样本，该海山链从太平洋的东太平洋海隆Siqueiros脊转换交叉点向西延伸200公里。 海山提供了一个独特的机会来检验远离扩散中心的熔体分布和来源变化的假设。 形成这些海山的熔融物提供了了解上地幔的地球化学窗口。这项研究包括一次海洋学巡航，以绘制目标区域的地图和取样。随后将对使用ALVIN载人深潜器和疏浚收集的样品进行地球物理数据处理和岩相学、岩石学和地球化学分析。 该研究的目标是开发新的，综合模型的上部岩石圈结构，变形和熔体分布在一个快速扩展的中心，并调查离轴熔融的动力学。该方法是跨学科的，包括分析地球物理和地球化学数据和地球动力学建模。将分析岩石样品的所有主要和微量元素，还将分析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，Pipkin中学是一所全国排名第一的学校，为密苏里州斯普林菲尔德市低收入中心城市的580名学生提供服务（贫困指数为78%）。教师将与研究人员密切合作，双方将共同创作教育材料。重点将放在探究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。编制的单元将通过课程资源网站广泛提供。