This presentation aims to enlighten the audience on the most important factors that control the partitioning of trace elements between plagioclase, clinopyroxene and melt.
Partition coefficients are simply the ratio of the concentration of an element between two phases in equilibrium, for example, between a mineral and a silicate melt. For trace elements, such mineral/melt partition coefficients are widely used to model petrogenetic processes in igneous systems. However, theoretical considerations lead us to expect that the values of partition coefficients will change with many variables, including both mineral and melt compositions, as well as temperature and pressure. If we can understand what controls the partitioning of trace elements into common rock forming phases, we can more accurately model these processes.
Plagioclase and clinopyroxene are two of the most common minerals in the earth’s crust. I will present an experimental study on the partitioning of trace elements between plagioclase/melt, clinopyroxene/melt and plagioclase/clinopyroxene in simple systems. I will outline the most important factors to consider when dealing with trace element partitioning in these phases and present models to predict relevant partition coefficients in any given condition. I will also compare these experimental results to natural samples from around the world.