Collaborative Research: Constraining the Volatile and Slab Flux in the Izu-Bonin-Mariana MARGIN using Geothermal Fluids, Phenocrysts and Melt Inclusions

根据这项合同，PIS将对伊苏-博宁-马里亚纳斯边缘的挥发物进行综合研究，包括利用最近喷发的火山灰熔体包裹体的SIMS测量对特定挥发物(H2O、CO2、Cl、S)和液体可溶元素(Li、B、K、Rb、Ba等)及其稳定同位素(d？11b、d？13C、d？18O、d？34s)进行系统分析。这一数据集将得到喷发的火成岩包裹体和喷发的火山和热液流体的二氧化碳和氦丰度和同位素测量(d13C和3He/4He)的补充。此外，这项研究将测量完整的气体成分和热液流体的氮同位素，以便通过对地面二氧化硫遥感测量的归一化，确定从整个弧段到今天的总挥发通量。合并后的数据集将使PI能够根据挥发成分(熔体包裹体数据)、以大洋基底、俯冲碳酸盐或有机沉积物(二氧化碳-氦和氮-氦体系)表示的板块通量的来源、从板块和地幔楔形物进入大气的当今挥发性通量(二氧化硫通量和火山气体成分)来量化板岩通量。这项研究研究了进出IBM系统的挥发物的通量和组成，以及挥发物在地幔中的分布及其随时间的地球化学演化。

Under this award, the PIs will carry out an integrated study of volatiles in the Izu-Bonin-Marianas margin that includes the analyses of specific volatiles (H2O, CO2, Cl, S) and fluid soluble elements (Li, B, K, Rb, Ba and others) as well as their stable isotope (?d?D, d?11B, d?13C, d?18O, d?34S) systematics utilizing SIMS measurements of melt inclusions of recently erupted tephra. This data set will be complemented by CO2 and He abundance and isotopic measurements (??d13C and 3He/4He) in erupted phenocysts and discharging volcanic and hydrothermal fluids. Additionally, the study will measure the complete gas composition and the N-isotopes of the hydrothermal fluids in order to determine the present-day total volatile flux from the entire arc through normalization to ground-based SO2 remote sensing measurements. The combined data set will allow the PIs to quantify the slab flux in terms of volatile composition (melt inclusion data), the source of the slab flux in terms of oceanic basement, subducted carbonates or organic sediments (CO2-He and N2-He systematics), the present day volatile flux to the atmosphere from the slab and mantle wedge (SO2 flux and volcanic gas compositions). The study addresses the flux and composition of volatiles into and out of the IBM system and the distribution of volatiles in the mantle and its geochemical evolution through time.