Quantitative Modeling of Infiltration in Layered Intrusions

点击翻译按钮获取中文摘要

9902183BoudreauA major field of inquiry in the earth sciences is the understanding of mechanisms of magma migration and how magma compositions can change as a result of this migration. Areas where this is of importance include the geochemistry of mantle melts and the understanding of how these melts change as they migrate to the surface of the earth. In addition, infiltration and reaction in mafic layered intrusions has been recognized as an important mechanism in changing both the mineralogy and composition of primary magmatic phases. In a number of cases, these features are associate with platinum-group element mineralization; hence, there is considerable economic interest in these problems as well. This study will combine a quantitative model for liquid-mineral equilibria with one-dimensional transport equations to develop a program for modeling magmatic reaction-transport phenomenon. The program is expected to be a useful tool to a broad range of igneous studies. This program will be general enough so users can specify a range of starting compositions (including inhomogeneous host rock compositions). For example, the program will allow calculation of reaction and chromatographic fronts as silicate liquid percolates through a porous solid matrix. In addition to the theoretical modeling, we plan parallel field studies of textural, chemical and mineralogical features of the Bushveld complex, South Africa. These field studies will help to constrain and compare results of the numerical models.