A central problem in Andean geophysics remains the accurate characterization of the overriding plate, specifically its composition, style of deformation, and thermal state. This collaborative proposal is for seismic analysis of digital array data and broadband data to image that crust/mantle wedge in two diverse Andean provinces: the region of flat subduction beneath central Peru, and the region of the westward-stepping subduction complex that comprises the northernmost Andes. Our objective is to map seismic structures in sufficient detail and accuracy that the results may be applied to understanding the dynamical and magmatic processes that shape the Andes. By combining these two markedly different provinces in a single study we endeavor also to resolve fundamental differences in deep structure between segments of the Andean arc.
