This research is focused on clarifying the origin and timing of magnetization recorded in a granitoid body (the Ecstall Pluton) within the Coast Mountains of British Columbia. Research to date has revealed that this pluton was likely magnetized by a process only recently recognized, which arises during unmixing of specific iron-titanium oxides. The unmixing process requires either slow cooling or reheating following the initial intrusion of the magma. The magnetism of the Ecstall pluton varies geographically in such a way that reheating due to a hot shear zone appears likely. The larger importance of this research is that the origin of the variation in magnetism will clarify the outstanding question of whether large portions of the western North American continental crust were accreted to the continent from thousand of kilometers away, as has been inferred from magnetism of this and other rock units in the region. The research entails fieldwork, geochronology, rock magnetism and paleomagnetism, and mineralogical studies including electron microscopy and other materials science techniques.
