Collaborative Research: Temporal and Spatial Variations of Magmatic Volatiles and Trace Elements in Glass Fragments and Phenocryst Inclusions in Pyroclastic Rocks...

Pelee火山爆炸性和非爆炸性喷发模式的交替为研究挥发物与喷发机制之间的关系提供了一个极好的自然例子。因此，本项目将定量检验Smith和Roobol （1990a）的假设，该假设认为Pelee火山喷发方式的主要控制因素不是岩浆成分，而是气体含量：富含挥发物的岩浆产生爆炸性的plian期活动，而缺乏挥发物的岩浆产生Pelee期活动。这将通过测量喷发前挥发物（H2O, CO2, Cl， F和S）的含量来完成，使用微红外光谱和电子和二次离子质谱显微镜（离子探针）对来自Pelee山的Plinian和Pelean矿床的斑晶中的幼年玻璃和熔融包裹体进行测量。微量元素将用离子探针测量。挥发物的演化和脱气历史将在基于主元素和微量元素的分数结晶模型和开放与封闭系统脱气模型的框架内解释。

9600029 Dixon Alternation between explosive and non-explosive eruptive modes at Mt. Pelee provides an excellent natural example to study the relationship between volatiles and eruptive mechanism. Accordingly, this project will test quantitatively the hypothesis of Smith and Roobol (1990a), which state that the main control on eruptive style of Mt. Pelee is not magma composition but gas content: volatile-rich magma generate explosive Plinian activity and volatile-poor magma generates Pelean activity. This will be accomplished by measuring the contents of pre-eruptive volatiles (H2O, CO2, Cl, F, and S) using microinfrared spectroscopy and electron and secondary ion mass spectrometry microscopy (ion probe) on juvenile glasses and melt inclusions in phenocrysts from both Plinian and Pelean deposits of Mt. Pelee. Trace elements will be measured using an ion microprobe. The evolution and degassing history of the volatiles will be interpreted within a framework of fractional crystallization models based on major and trace elements and open versus closed system degassing models.