During emplacement of large masses of magma, country rock material is transferred out of the path of the ascending/inflating magma body, but precisely how this is accomplished is a long-standing problem. This project will approach the question by examining selected examples in which pluton roofs (as opposed to the more commonly preserved walls) are available for study, in the hopes they preserve evidence for the space-accommodating mechanism that is not evident in pluton walls. The work will involve detailed mapping, strain analysis, fabric study and other microstructural techniques to constrain three-dimensional structural reconstructions of emplacement-related deformation. The Yerington batholith, Nevada, the Mount Powell batholith, Montana and other examples will be studied. Results will address how material was transferred during emplacement and will help refine the relationship between emplacement of plutons and magma chamber evolution.
