Observational Constraints on Melt-Rock Reactions during Melting of the Upper Mantle

上地幔熔融过程中熔岩反应的观测限制

• 批准号: 0096533
• 负责人: Craig Lundstrom
• 金额: $ 9.58万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0096533&HistoricalAwards=false
• 关键词: Observational; Constraints; Melt; Rock; Reactions

Recent work has indicated that dunite bodies in ophiolites, and presumably also in layered ocean crust, represent melt transport conduits through which basaltic melt has migrated and interacted chemically. In this proposal, Lundstrom proposes to test two aspects of this general hypothesis. First, he proposes to test the hypothesis that the melts that moved through the dunites are in fact very enriched and produced by melting of mafic heterogenieties in the mantle. He proposes to do this by measuring the isotopic compositions of oxygen and lithium in mantle spinels from ophiolite samples and mantle xenoliths. A second test, using samples from the Trinity ophiolite, is to determine whether there exist gradients in lithium and other incompatible element isotopes as a function of distance from dunite bodies.

最近的研究表明，蛇绿岩中的纯橄榄岩体（可能也存在于层状海洋地壳中）代表了熔体输送管道，玄武岩熔体通过该管道迁移并发生化学相互作用。在这个提案中，伦德斯特罗姆建议测试这个一般假设的两个方面。首先，他提议检验这样的假设：穿过沙丘的熔体实际上非常丰富，是由地幔中镁铁质异质性的熔化产生的。他建议通过测量蛇绿岩样本和地幔捕虏体中地幔尖晶石中氧和锂的同位素组成来做到这一点。第二项测试使用来自 Trinity 蛇绿岩的样品，以确定锂和其他不相容元素同位素中是否存在梯度，作为与纯橄榄岩体的距离的函数。