The Notch Peak pluton, a Late Jurassic granitic stock, intrudes early Paleozoic miogeoclinal strata in the House Range, western Utah. As part of a detailed study to determine textural and chemical changes related to the intrusion, a paleomagnetic reconnaissance has been made of the pluton and its contact aureole. Steep, scattered magnetizations with both polarities present are found in the pluton upon alternating field (af) demagnetization, and they may reflect an original thermoremanence in magnetite that was acquired over at least one polarity reversal. Limestones and argillites in the Big Horse Canyon Member of the Orr Formation (Late Cambrian) were sampled at four stratigraphically controlled sites ranging from unaltered country rock to marble. The site farthest from the pluton is well behaved upon progressive thermal demagnetization and yields a low--inclination, reversed Paleozoic direction by 400 ¿C. The sites nearer the stock generally have a diffusely defined, two--polarity, high--inclination magnetization that reflects remagnetization by the pluton. This magnetization is removed above 300 ¿C, and af demagnetization suggests that it resides in fine--grained hematite. Of these sites, one appeared nearly unaltered in thin section, whereas the others range from hornfels to skarn. The remagnetization resulted from a late oxidation event related to the intrusion, perhaps from mobilization of groundwater; thus, the country rock has been remagnetized chemically rather than thermally. These results suggest that paleomagnetism may be a useful tool for detecting altered zones around plutons. In addition, no consistent, high--blocking--temperature magnetization was found in the aureole rocks; the magnetization of the hornfels was easily measurable at higher steps, but directions changed erratically, and this behavior in part results from the presence of pyrrhotite.