The East Panama deformed belt is defined here as a seismically active, on- and offshore belt of deformed Late Cretaceous-Neogene rocks that forms a diffuse tectonic boundary between the eastern Isthmus of Panama and South America. Satellite imagery and geologic maps of eastern Panama compiled from previous studies indicate that northwest-striking, left-lateral strike-slip faults form the major Neogene tectonic structures in the onshore part of the deformed belt. The best studied onland strike-slip fault is characterized by left-stepping, en echelon folds that deform rocks ranging in age from Cretaceous to late Miocene and terminates at a high angle of intersection...