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

• 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

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.

就体积而言，山脊岩浆作用是地球上最重要的化学分异过程。绘制代表地幔的岩石（即橄榄岩）的化学和矿物学异质性图并将其与海底喷发的熔岩（即玄武岩）联系起来，可以提供有关地球热收支的重要信息，并有助于约束地幔对流模型。这项研究对 2001 年 AMORE 探险队从北极海底 Gakkel 洋中脊扩展中心收集的橄榄岩进行了地球化学研究。这次探险带回了橄榄岩宝库，其范围和保存状况都是无与伦比的。有了这些岩石，我们现在可以回答对我们理解洋中脊过程至关重要的问题。这项研究的目标包括确定橄榄岩的成分变化，因为这可以告诉我们地幔的结构和异质性，检查在局部范围内观察到的熔体消耗是否与当前的熔化过程有关或代表以前的熔化事件，并确定年龄进入熔融带的亚脊地幔分布。主量元素和痕量元素分析、岩相学以及钕和锇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以及让初中生和高中生及其老师参与研究。