Calc-Alkaline Magma Ascent Rates: An Experimental Investigation

该项目研究富含挥发性物质的火山系统，如圣海伦斯火山的岩浆上升动力学。通过对天然岩样的岩石学研究，获得喷发前岩浆的温度、氧逸度和溶解挥发分数据。未来两年计划的项目是：(1)详细研究1980年圣海伦斯山隐形穹顶形成期间的岩浆动力学，(2)调查1985-86年期间同一系统中的岩浆动力学变化，(3)与K.Cashman合作的湿硅质岩浆中斜长石生长速率的实验，以及(4)两个成分和岩浆性质不同的火山系统--加利福尼亚州朗谷的护城河流纹岩和内华达州火山口平坦的夏威夷玄武岩的岩浆上升速率研究。

This project deals with the dynamics of magma ascent in volatile-rich volcanic systems such as Mount St. Helens. Petrological studies of natural samples are used to obtain temperature, oxygen fugacity and dissolved volatile data for the preeruption magmas. Projects planned for the next two years are: (1) A detailed study of the magma dynamics during 1980 cryptodome formation at Mount St. Helens, (2) An investigation of the changes in magma dynamics in the same system over the 1985-86 period, (3) Experiments on plagioclase growth rates in wet silicic magmas in collaboration with K. Cashman, and (4) Magma ascent rate studies of two volcanic systems of contrasting composition and magmatic properties, the Moat Rhyolites of Long Valley, Ca., and the Hawaiian basalts of Crater Flats Nevada.