Widespread Late Paleozoic remagnetization of Appalachian sedimentary carbonates has been cited as evidence for large-scale lateral migration of magnetite-forming fluids during the Alleghenian Orogeny. Proponents of this idea hope that paleomagnetic studies can be used to date fluid migration events and to delimit the regions affected by them. However, even though Permocarboniferous (Kiaman Interval) remagnetizations residing in magnetite are now well documented in many Appalachian carbonate units, it is not at all certain that remagnetization is due to chemical diagenesis. An alternative idea is that remagnetization is a consequence of thermal activation of pre- existing magnetite, and may be unrelated to alleged fluid migration events. It is important therefore to test for evidence of chemical and thermal influences on the remagnetization process. The PI will conduct field and laboratory tests for these two different remagnetization mechanisms in a systematic study of Paleozoic carbonates of the Appalachian basin.