Violence and Volume: an experimental study of CO2 driven eruptions of Colli Albani

意大利科利阿尔巴尼火山杂岩的Pozzolane Rosse喷发（457 ka）是一次由低粘度、低SiO2、镁铁质岩浆组成的高容量爆发性喷发。P. Rosse岩浆的成分也富含CO2和CaO。在喷发体积随SiO2含量变化的曲线图上，这种喷发的体积福尔斯落在爆炸性喷发的范围之外。在这里，我们将首次确定foiditic熔体的粘度，并确定CO2对这些熔体的粘度的影响。我们的目标是获得洞察的原因，这样一个低SiO2熔体爆发的暴力和体积。这种喷发通常只发生在富含SiO2的岩浆中，因为气泡不能轻易地从高粘度的岩浆中逸出。一般而言，可以预期的是，球粒状熔体的粘度是如此之低，以至于CO2气泡会溢出。

The Pozzolane Rosse eruption (457 ka) of the Colli Albani volcano complex in Italy was a high volume explosive eruption of foiditic, low viscosity, low SiO2, mafic magma. The composition of the P. Rosse magma was also CO2- and CaO-rich. The volume of this eruption falls outside the range of explosive eruptions on a plot of eruption volume as a function of SiO2 content. Here we will determine the viscosity of foiditic melts for the first time; and also determine the effect of CO2 on the viscosity of these melts.The goal is to obtain an insight into the reason why such a low SiO2 melt erupted with such violence and volume. Such eruptions usually only occur in SiO2–rich magmas, as bubbles can not escape easily from high-viscosity magmas. In general, it would be expected that the viscosity of the foiditic melt was so low that CO2 bubbles would effusively escape.