Study on fluid dynamics of gaseous transfer in magma chambers

为了研究岩浆室中气体迁移的流体动力学，进行了以下两类实验：第一组实验是利用对流流体中的小重颗粒，研究固体或气体颗粒对岩浆室对流的影响。结果表明，当颗粒浓度足够小时，对流基本不受其存在的影响；当颗粒浓度高于某一临界值时，对流运动发生了很大的变化。理论分析表明，颗粒和液体混合物的体积密度变化与对流模式有关。这一结果发表在《火山学和地热研究》杂志上。第二系列实验旨在研究气泡如何从粘性较低的下层迁移到双层岩浆室中，该岩浆室在结晶时释放挥发物。结果表明，气泡在界面上形成一层薄层，在重力作用下变得不稳定，产生两相羽流，上升并产生液体的粗大混合物。理论分析表明，这种不稳定的条件应由气体流量和气泡直径控制。这一结果发表在《地球和行星科学快报》上。这些实验结果被应用于岩浆室中的现象，如层状侵入的起源。这些实验的地质意义被讨论并发表在《自然》和《国际现代物理杂志》上。

The following two types of experiments were conducted in order to investigate fluid dynamics of gaseous transfer in magma chambers.The first series of the experiments is those on the effect of solid or gas particles on convection in magma chamber using small heavy particles in convecting fluid. The results show that when the concentration of particles is sufficiently small convection is basically unaffected by their presence ; however, when the concentration is above a critical value, the convective motion is considerably altered. Theoretical analyzes suggest that the mode of convection is accounted for the evolution of bulk density of the particle and liquid mixture. This result is published in Journal of Volcanology and Geothermal Research.The second series of experiments were designed to investigate how the gas bubbles migrate into the more viscous upper layr from a less viscous lower layr in a two layr magma chamber which exsolves volatiles as it crystallizes. The results shows that bubbles form a thin form layr at the interface which becomes gravitationally unstable, giving rise to two phase plumes which rise and produce a coarse mixture of the liquid. Theoretical analyzes suggest that the condition for this type of instability should be controlled by the gas flux and diameter of gas bubbles. This result is published in Earth and Planetary Science Letters.These experimental results were applied to phenomena in magma chambers such as origin of layred intrusions. The geological implications of the experiments are discussed and are published in Nature and International Journal of Modern Physics.