EaGER:The influence of CO2 solubility on trace element partitioning in clinopyroxene-alkali basalt systems: towards the development of a magmatic carbon meter

EaGER：二氧化碳溶解度对单斜辉石-碱性玄武岩系统中微量元素分配的影响：致力于开发岩浆碳计

• 批准号: 1057611
• 负责人: Julia Bryce
• 金额: $ 4.5万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1057611&HistoricalAwards=false
• 关键词: EaGER; influence; CO2; solubility; trace

This EaGER will support a feasibility study to evaluate the influence of carbon dioxide (CO2) on the concentration of trace elements in clinopyroxene, in equilibrium with basaltic magma. The ultimate goal of the experimental plan is to assess if the trace element compositions recorded in clinopyroxene (cpx) may serve as a proxy for magmatic CO2. If successful, results from the study could be applied both to those wishing to decipher the source history of a magma as well as the Earth's degassing history. The proposed research plan will complement to existing experiments in CO2-diopside-albite ternary systems that show a large variation in cpx-melt partitioning for alkali, alkaline earth and high field strength elements between carbonatitic and silicate liquids. Since CO2 enrichment is often concomitant with water enrichment in mafic lavas, the experimental design also includes experiments with varying water content so that it is possible to assess the role of dissolved water and carbonate on elemental partitioning. The target starting composition for this pilot study will be chosen from an in-hand suite of clinopyroxene-phyric, calcium and sodium-rich alkaline basalts from Mt. Etna, Sicily (MgO ~ 6 wt. %).Reconstructing the history of volatile emissions on Earth is an essential part of understanding climate controls, yet volatile mobility hampers preservation in the rock record. A recent study using large statistical analysis of recent volcanism has linked the latest episode of deglaciation with enhanced subaerial volcanism and, presumably, subsequently increased volcanic carbon dioxide emissions. This potential role of solid Earth carbon storage in promoting deglaciation impacts the long-established argument that climate is controlled by ocean-atmosphere exchange alone. Presently, other than by amassing records of volcanism chronologically constrained to coincide with episodes of deglaciations, it is difficult to test and refine this hypothesis from the rock record alone, largely because CO2 is not quantitatively contained during magma transport at shallow depths, with up to 90% degassed prior to eruption. The proposed research activities seek to identify whether magmatic carbon dioxide contents impact high field strength element chemistry of basaltic magmas, thereby potentially providing a proxy that enables documentation of carbon dioxide contents in magmas. Links with a world-class experimental facility will enhance technique development in newly established laboratories at UNH. The award provides postdoctoral support for a promising female scientist on an interdisciplinary project within a collaborative multi-institutional work group.

这一渴望将支持一项可行性研究，以评估二氧化碳（CO2）对斜层岩浆平衡中斜向元素浓度的影响。实验计划的最终目标是评估斜氧烯（CPX）中记录的微量元素组成是否可以作为岩浆CO2的代理。如果成功的话，这项研究的结果既可以应用于那些希望破译岩浆的来源历史以及地球脱气病史的人。拟议的研究计划将补充CO2-DIOPSIDE-ALBITE三元系统中的现有实验，这些实验表明，碱，碱性地球的CPX熔体分配差异很大，碳酸盐和硅酸盐液体之间的高田间强度元素。由于二氧化碳富集通常与镁铁质熔岩中的水富集同时，因此实验设计还包括具有不同水含量的实验，因此可以评估溶解的水和碳酸盐在元素分配中的作用。这项试验研究的目标起始组合物将从手工套件中选择，从埃特纳山（Mgo〜6 wt。％）中的clinopyroxene-phyric，钙和富含钠的碱性玄武岩。重建地球上挥发性挥发物的历史是了解气候控制的一部分，但要保存摇摆不定的人。最近使用对最近火山的大规模统计分析的一项研究将最新的脱气发作与增强的亚赛火山症联系起来，大概随后增加了火山二氧化碳的排放。固体碳储存在促​​进脱位中的潜在作用影响了长期以来的论点，即气候仅受海洋 - 大气交换控制。目前，除了积累时间顺序的记录与与脱脂型发作相吻合的记录外，很难仅凭岩石记录来检验和完善这一假设，这主要是因为在浅层深度的岩浆运输过程中，二氧化碳在较浅的深度均未定量，最高含量为90％，高达90％。拟议的研究活动旨在确定岩浆二氧化碳含量是否影响玄武岩岩浆的高田间强度元素化学性质，从而有可能提供代理，该代理能够证明岩浆中二氧化碳含量的文献。与世界一流的实验设施的联系将增强UNH新成立的实验室的技术开发。该奖项为合作多机构工作组的跨学科项目的有前途的女科学家提供了博士后支持。