Diagenetic magnetite carries ancient yet secondary remanence in some Paleozoic sedimentary carbonates

Many sedimentary carbonate rocks carry stable magnetizations that can be shown to reside in magnetite. When such magnetizations are observed, it is often argued or demonstrated that the magnetite was incorporated into the sediment during deposition. However, paleomagnetic and rock magnetic studies in conjunction with analyses of magnetic extracts from the Helderberg and Bonneterre carbonates (United States) indicate that the magnetite present in these rocks is most likely of diagenetic (i.e., postdepositional) origin.