Paleomagnetic vector data from granite plutons are commonly robust and well-clustered, unlike paleomagnetic data from deformed sedimentary rocks. However, because no paleohorizontal references plane (such as bedding in layered rocks) is available in most plutons, their use in tectonic reconstructions has been severely limited because any proposed latitudinal translation can just as easily be explained by in situ tilting of the pluton. This ambiguity has led to a major controversy concerning whether or not some Tertiary plutons in the pacific northwest originated near Baja, California and subsequently moved north to their present position, or formed near their present position and were then tilted. This project will examine one of these plutons and use a widely-applicable pressure indicator (Aluminum in hornblende) to calculate a paleohorizontal plane for the pluton. Successful results will not only provide a resolution of the "Baja-BC" controversy, but more importantly would demonstrate the potential to obtain paleohorizontal reference planes for plutons in general.
