Water Speciation and Viscosity of Hydrous Melts

水形态和含水熔体的粘度

• 批准号: 0125506
• 负责人: Youxue Zhang
• 金额: $ 29.68万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125506&HistoricalAwards=false
• 关键词: Water; Speciation; Viscosity; Hydrous; Melts

ZhangEAR-0125506Viscosity of hydrous silicate melts plays a critical role in bubble growth, magma fragmentation and volcanic eruptions. This proposal requests funding to develop a new and long-term project for viscosity measurement using a novel technique developed over the years in my lab. It is based on the equivalence between glass transition temperature and the apparent equilibrium temperature of the hydrous species reaction in silicate melt. In order to obtain viscosity using this method, the equilibrium of the hydrous species reaction must also be characterized. Such data are important in their own right in understanding melt structure, water solubility and diffusion in magma, and D/H fractionation between water vapor and melt. In the three years of the grant period, we will concentrate on the following: a) speciation and viscosity at high pressures for hydrous rhyolitic melt up to 8 GPa; b) speciation equilibrium in hydrous dacitic melts and the viscosity of such melts to high dissolved H2O content (up to 8 wt% dissolved H2O); and c) development of more accurate viscosity models for hydrous rhyolitic and dacitic melts. The new viscosity model will be applied to re-evaluate previous results of bubble growth and magma fragmentation.

张EAR-0125506水合硅酸盐熔体的粘度在气泡生长、岩浆破碎和火山喷发中起着至关重要的作用。 该提案要求提供资金来开发一个新的长期粘度测量项目，该项目使用我实验室多年来开发的新技术。 它基于玻璃化转变温度和硅酸盐熔体中含水物质反应的表观平衡温度之间的等效性。 为了使用该方法获得粘度，还必须表征含水物质反应的平衡。 这些数据本身对于了解熔体结构、岩浆中的水溶性和扩散以及水蒸气和熔体之间的 D/H 分馏非常重要。 在三年的资助期内，我们将重点关注以下方面：a）高达8 GPa的水合流纹岩熔体在高压下的形态和粘度； b) 水英英岩熔体中的形态平衡以及此类熔体在高溶解 H2O 含量（高达 8 wt% 溶解 H2O）下的粘度； c) 开发更准确的含水流纹岩和英安岩熔体的粘度模型。 新的粘度模型将用于重新评估先前的气泡生长和岩浆破碎结果。