Collaborative research: Isotopic Investigation of Gakkel Ridge peridotites to determine the length scale, origin and age of heterobeneities in the sub-ridge mantle

合作研究：对 Gakkel 岭橄榄岩进行同位素研究，以确定下脊地幔异质性的长度尺度、起源和年龄

基本信息

批准号：
0930487
负责人：
Henry Dick
金额：
$ 15.44万
依托单位：
Woods Hole Oceanographic Institution
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-01 至 2012-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0930487&HistoricalAwards=false
关键词：
Collaborative research Isotopic Investigation Gakkel

项目摘要

Ridge magmatism is by volume the most important chemical differentiation process on the planet. Mapping the chemical and mineralogical heterogeneities in rocks representative of the mantle (i.e., peridotites) and linking them to the lavas erupted on the seafloor (i.e., basalts) provides essential information on Earth's heat budget and helps to constrain mantle convection models. This research carries out geochemical studies of peridotites collected from the Gakkel mid-ocean ridge spreading center on the Arctic seafloor by the 2001 AMORE expedition. This expedition returned a treasure trove of peridotites that is unsurpassed in its extent and preservation. With these rocks, questions fundamental to our understanding of mid-ocean ridge processes can now be answered. Goals of this research include determining compositional variations of the peridotites because this tells us about the structure and heterogeneity of the mantle, examining if melt depletions observed on a local scale are related to the current melting process or represent previous melting events, and determining the age distribution of the sub-ridge mantle that enters the melting zone. Major and trace element analyses, petrography, and neodymium and osmium isotope systematics will be used to help answer these questions. Broader impacts of the work include training students and including middle and high school students and their teachers in the research.

山脊岩浆作用是地球上最重要的化学分化过程。绘制代表地幔（即橄榄岩）的岩石中的化学和矿物质异质性，并将它们与海底爆发（即玄武岩）爆发的熔岩联系起来，提供了有关地球热预算的基本信息，并有助于限制披风对流模型。这项研究对2001年阿莫尔探险队（Amore Expedition）从北极海底的Gakkel Mid-cean Ridge蔓延中心收集的橄榄岩进行了地球化学研究。这次探险队返回了一群橄榄岩的宝库，其程度和保存是无与伦比的。借助这些岩石，现在可以回答我们对中海脊过程的理解的问题。这项研究的目标包括确定橄榄岩的组成变化，因为这告诉我们地幔的结构和异质性，检查是否在局部规模上观察到的熔体耗竭是否与当前的熔化过程有关或代表先前的熔融事件，并确定近距离架的年龄分布，从而进入了熔融区。专业和痕量元素分析，岩石学以及新近二聚体和同位素系统学将用于帮助回答这些问题。这项工作的更广泛影响包括培训学生，包括中学生及其老师在研究中。