Occurrence and Origin of Hercynian Remagnetization in Proterozoic Mafic Rocks in the Anti‐Atlas Belt, Morocco

The rarity of high‐quality paleomagnetic data leads to significant uncertainties regarding the paleogeography of the West African Craton (WAC) during the Proterozoic. Several well‐dated mafic intrusive suites in the Anti‐Atlas Belt (AAB) of Morocco present an opportunity for paleomagnetic studies. Here, we report the paleomagnetic and rock magnetic results for mafic intrusions from seven inliers in the AAB. Thirty‐seven sites show a characteristic remanent magnetization with SE‐shallow directions, of which the corresponding paleomagnetic pole overlaps with the ∼300 Ma segment of the apparent polar wander path of the WAC, coeval to the Hercynian orogeny that pervasively affected the AAB. No correlation is observed between the trend and the remanence declination of the dikes, and the anisotropy of magnetic susceptibility is decoupled from the trend of the dikes. Additional rock magnetic data indicate the remagnetization mechanism is chemical instead of purely thermal. Koenigsberger diagrams show that most of the samples have been remagnetized by hydrothermal/metamorphic fluids, with attendant mineralogical changes that are visible in regional hyperspectral imagery. Forty‐six sites fail to yield consistent directions within a site, which could be due to lightning, significant leaching of iron minerals, or crystallization of coarse‐grained magnetite during background greenschist metamorphism that lowers the relaxation time of the remanence. Following this approach, we also re‐evaluate the published paleomagnetic results from the Proterozoic rocks in the AAB. We tentatively delineate a Hercynian overprint front in the AAB, the east of which seems to be less affected and has a better chance for isolating primary paleomagnetic results.