9404697 Tobisch Very large granitic bodies are a common feature in the development of magmatic arcs and convergent continental margins, however despite considerable study the mechanisms of ascent, assembly and emplacement of granitic magma within mid-to-upper crustal levels are still controversial. This project will test a possible solution involving whether elongate, large-volume Early- Late Cretaceous plutons typical of the Sierra Nevada, California, represent dike-fed magma chambers rather than diapirs. the work will involve establishing the geometry and kinematics of magma flow in the pluton and model the assembly and emplacement, while constraining the ascent mechanism from the flow dynamic and observed wall rock structures the main tools will be anisotropy of magnetic susceptibility (AMS) image analysis of magmatic fabrics and field observation. Results are expected to provide sufficient documentation to help resolve the magma room problem and help develop a tectonic model of the Sierra Nevada that more accurately treats the magmatic activity.
