Multiphase Modeling of Solidification and the Dynamics of Magma Chambers

[805336 .伯甘特]火成岩的化学演化基本上是晶体-液体分离的过程。本研究的目的是发展和扩展一种多相结晶的数值方法，明确地允许在岩浆体内部和顶部、墙壁和底部的边界层中晶体和熔体之间同时进行相对运动。这将包括许多对地质应用至关重要的过程，如热浮力和成分浮力、变粘度、凝固和熔化的动力学效应、晶体沉降、晶体羽状和不稳定性、晶体糊状区域的成分对流，以及岩浆室底部的晶体夹带。一些模型已经实现，但与成核和共晶行为的细节以及可变流变特性和功能有关的重要特征需要进一步完善。该模型在海洋中脊玄武岩系统的冷却和动力学以及涉及对流活动引起的堆积桩的混合和破坏的系统中的具体应用将被探讨。

9805336BergantzThe chemical evolution of igneous rocks is fundamentally a process of crystal-liquid segregation. The objective of this research is to develop and extend a numerical approach to multiphase crystallization that explicitly allows for relative motion between crystals and melt simultaneously in the interior of the magma body and the boundary layers at the roof, walls and floor. This will include many processes that are central to geological applications such as thermal and compositional buoyancy, variable viscosity, kinetic effects of solidification and melting, crystal settling, crystal plumes and instabilities, compositional convection in regions of crystal mush, and entrainment of crystals from magma chamber floors. Some of the model is already implemented but important features relating to the details of nucleation and eutectic behavior and to variable rheological properties and functions require further refinement. Specific applications of this model to the cooling and dynamics of mid-ocean ridge basaltic systems and to systems involving mixing and disruption of cumulate piles by convective activity will be explored.