Induced and remanent magnetic analyses have been performed on drilled samples from 2 generations of unweathered diabase dikes, a breccia dike, and the host tonalite which make up the basement on which the Russell Dam foundation was poured. The maximum magnetic foliation plane for most samples, defined by anisotropy of magnetic susceptibility (AMS) data, is vertical and is oriented perpendicular to maximum stresses developed in the region during mid-late Paleozoic time. The excellent AMS data consistency between units of different ages is interpreted to be indicative of stress controlled magnetite recrystallization at the site. It is inferred that this recrystallization is responsible for the multicomponent remanent magnetization (RM) in these samples, which was probably acquired over long periods of time.