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

尽管所有的地幔热柱玄武岩都比MORB更湿，但PI铅最近的工作表明，与含有俯冲岩石圈的地幔热柱组分(EM型)有关的玄武岩比与普通地幔或轻度HIMU源(湿热柱)有关的玄武岩较少潮湿(“湿”热柱)。这种损耗的可能解释是，在俯冲过程中，从岩石圈有效地提取了水(92%)。根据这一奖项，私人投资研究所将通过以下方式测试和完善这一假设：(1)扩展现有的数据集，以包括H-、D-、O-同位素和氯浓度；(2)表征冰岛以北和基础海山链内的大洋岛和大洋中脊玄武岩(MORB)采样的不同地幔成分的H2O、CO2和Cl浓度和稳定同位素组成(H-、C-和O-同位素)；以及(3)开发BOX模型，以帮助理解地幔中水的时间演变、FOZO的起源以及MORB水浓度的区域不均一性。

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.