各位老师和同学：
应Eiichi Takahashi研究员邀请，日本Japan Agency for Marine-Earth Science and Technology的M. Hamada研究员近期将访问我所，并于本周三和周五做“同位素室学术报告”2017年第36次报告和第37次报告。欢迎大家参加并积极参与讨论！
报告题目1：Hydrogen in nominally anhydrous minerals: An overview and volcanological applications
报 告 人：Prof. M. Hamada (Japan Agency for Marine-Earth Science and Technology)
报告时间：10月25日（周三）上午10:00
报告地点：综合楼702会议室
报告题目2：Water in arc basalt magmas: Constraints from high-pressure experiments and FTIR analysis
报 告 人：Prof. M. Hamada (Japan Agency for Marine-Earth Science and Technology)
报告时间：10月27日（周五）上午10:00
报告地点：综合楼702会议室
报告人简介:
M. Hamada 研究员，2006年在东京大学获得博士学位，2013以来在日本的Japan Agency for Marine-Earth Science and Technology工作。M. Hamada研究员目前在EPSL、CMP等国际顶级刊物发表了多篇关于岛弧岩浆成因、岩浆过程水的行为、洋岛玄武岩的起源和地球化学变化、以及岩浆减压过程气泡成核的动力学方面的论文。他开发了新的测量水含量的技术，可以利用FTIR测量无水矿物水的含量，特别是长石矿物中水的含量。
10月25日报告摘要:
Trace amounts of hydrogen are commonly accommodated in the crystal structure of nominally anhydrous minerals (NAMs). Since the 1960s, such hydrogen in NAMs has been studied as an indicator of water？rock interactions and a proxy of H2O dissolved in silicate melts. In the last 15 years, many experimental studies have been performed to determine partition coefficients of hydrogen between peridotite minerals (olivine, orthopyroxene, clinopyroxene, etc.) and melt. Plagioclase, which is the most common mineral in Earth’s crust, is one of the NAMs. However, hydrogen in plagioclase was less studied compared with those NAMs in mantle rocks. We analyzed hydrogen in plagioclase collected from Izu-Oshima volcano, a frontal-arc volcano in Izu arc, by using FTIR. Based on the FTIR analysis, we propose that 1) basalt magmas beneath Izu-Oshima volcano are H2O-saturated from shallower level to deeper level and 2) they undergo polybaric degassing during their ascent in the conduit and eruption.
10月27日报告摘要:
The slab-derived fluids released from a subducted slab ascend into the mantle wedge, so that arc magmas, in general, are characterized by their hydrous nature. Estimation of H2O in arc basaltic rocks provides important constraints on pre-eruptive P-T conditions of magmas. However, it is difficult to estimate concentration of dissolved H2O in melts by using erupted volcanic rocks because H2O is subject to degas during eruption.
Conducting high-pressure melting experiments is one of powerful approaches to constrain H2O in arc basaltic magmas. Micro-analysis of melt inclusions by using FTIR or SIMS are alternative method to estimate water content in magma. Dr. M. Hamada has been working on water content in magma of Japanese Quaternary volcanoes combining both high pressure experiments (Hamada et al. 2008 CMP) and FTIR analysis. In particular, he developed a new method to estimate water content in magma by analyzing water content in plagioclase using FTIR (Hamada et al. 2011, 2013 EPSL). In this talk, he will overview these works and will show his most recent works.
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