Collaborative Research: Temporal Evolution of Mantle Water: Quantifying the Effects of Recycling Efficiently Dehydrated Lithosphere into the Deep Mantle

合作研究：地幔水的时间演化：量化有效脱水的岩石圈循环到地幔深处的影响

• 批准号: 0351149
• 负责人: Jacqueline Dixon
• 金额: --
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0351149&HistoricalAwards=false
• 关键词: Collaborative; Research; Temporal; Evolution; Mantle

Though all mantle plume basalts are wetter than MORB, recent work by the lead PI has shown that basalts associated with mantle plume components containing subducted lithosphere (EM-type) are less wet ("damp" plumes) than those associated with a common mantle or mildly-HIMU source (wet plumes). The likely explanation for this depletion is that water is efficiently extracted (92%) from the lithosphere during the subduction process. Under this award the PIs will test and refine this hypothesis by (1) expanding the existing data sets to include H-, D-, and O-isotopes and Cl concentrations; (2) characterizing H2O, CO2, and Cl concentrations and stable isotopic compositions (H-, C-, and O-isotopes) of different mantle components as sampled by oceanic island and mid-oceanic ridge basalts (MORB) north of Iceland and within the Foundation Seamount Chain; and (3) developing box models to help understand the temporal evolution of water in the mantle, the origin of FOZO, and the regional heterogeneity in MORB water concentrations.

虽然所有的地幔柱玄武岩都比MORB更潮湿，但PI领导的最新研究表明，与包含俯冲岩石圈（EM型）的地幔柱成分相关的玄武岩比与普通地幔或轻度HIMU源（湿羽）相关的玄武岩更不潮湿（“湿”羽）。对这种消耗的可能解释是，在俯冲过程中，水被有效地从岩石圈中提取（92%）。根据该奖项，PI将通过（1）扩展现有数据集以包括H-，D-和O-同位素和Cl浓度来测试和完善这一假设;（2）确定H2O、CO2和Cl浓度和稳定同位素组成（H-，C-，大洋岛和洋中脊玄武岩（MORB）样品中不同地幔组分的氧同位素组成（3）开发箱形模型，以帮助了解地幔中水的时间演化、FOZO的起源以及MORB水浓度的区域异质性。