Testing the Significance of Melt Inclusions for Ocean Ridge Petrogenesis

测试熔体包裹体对洋脊成岩作用的意义

• 批准号: 0850442
• 负责人: Charles Langmuir
• 金额: $ 33.28万
• 依托单位: Harvard University
• 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: 2009-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0850442&HistoricalAwards=false
• 关键词: Testing; Significance; Melt; Inclusions; Ocean

This research tests the fidelity of melt inclusion compositions and provides new insights on the generation of magmas at ocean ridges, the most abundant volcanic province on Earth. The work involves examining the compositions of small melt inclusions in olivine crystals in seafloor volcanic rocks. The work will determine if the inclusions indicate initial conditions of magma formation or if they are modified by late-stage processes occurring at shallow crustal levels. The sample suite comes from the FAMOUS segment of the mid-Atlantic Ridge and the Gakkel Ridge in the Arctic. This study represents the first comprehensive, quantitative, and consistent dataset of olivine melt inclusions for multiple samples. Samples are phyric and primitive in composition. They have well-developed local variations that have been ascribed to melting column effects. Geochemical work includes the analysis of major, volatile and trace elements in melt inclusions from 15-20 samples. Questions to be addressed include: (1) are unusual compositions a common feature of melt inclusions from various samples; (2) is the occurrence of these unusual compositions related to segment position, lava type, or mineralogy; and (3) are major and trace element variations consistent with predictions from petrogenetic models or are they better explained by diffusion in the host crystal. Broader impacts of the work include engaging undergraduates in research and incorporation of results into university courses. It will support a postdoctoral fellow whose gender is under-represented in the sciences and increase bonds between a French and US laboratory. The work will also be featured in a new exhibit at the Harvard Museum of Natural History (HMNH). Geochemical data will be archived in PetDB. a public and Internet accessible database funded by NSF.

这项研究测试了熔体融合成分的忠诚度，并提供了有关地球上最丰富的火山省海洋山脊的岩浆产生的新见解。 这项工作涉及检查海底火山岩橄榄石晶体中小熔体夹杂物的组成。 这项工作将确定包含物是否指示岩浆形成的初始条件，还是通过在浅层地壳水平发生的晚期过程进行修改。 样本套件来自大西洋山脊的著名部分和北极的Gakkel Ridge。 这项研究代表了多个样品的橄榄石熔体夹杂物的第一个综合，定量和一致的数据集。 样品是植物和原始的组成。 它们具有良好的局部变化，这些变化已归因于熔体柱效应。 地球化学工作包括对15-20个样品熔体夹杂物中的主要，挥发性和微量元素的分析。 要解决的问题包括：（1）是不同样本中融合物的常见特征； （2）是这些与细分位置，熔岩类型或矿物学有关的异常组成的发生； （3）是主要的，痕量元素变化与岩发生模型的预测一致，或者是通过宿主晶体扩散更好地解释的。 这项工作的更广泛的影响包括使大学生参与研究和将结果纳入大学课程。 它将支持一个博士后研究员，其性别在科学中的代表性不足，并增加了法国和美国实验室之间的债券。 这项工作还将在哈佛自然历史博物馆（HMNH）的新展览中展出。 地球化学数据将在PETDB中存档。由NSF资助的公共和互联网可访问的数据库。