Magnetostratigraphic susceptibility of the Frasnian-Famennian boundary (Upper Devonian) in southern Oklahoma and its relationship to the type area in southern France
Crick Rex, E.; Ellwood Brooks, B.; Over, D.J.; Feist, R. Girard Catherine
Circular - Oklahoma Geological Survey 105: 71-82
A magnetosusceptibility event and cyclostratigraphy (MSEC) method is used to establish a nonpolarity-based magnetostratigraphic susceptibility (MSS) between the stratotype region for the Frasnian-Famennian (F-F) boundary sequence in the Montagne Noire of southern France and two F-F sequences in the Arbuckle Mountains and Criner Hills of southern Oklahoma. Despite differences in depositional environment, the MSS is remarkably consistent and can be described in the context of a hierarchy of magnetozones that allow extension of correlation away from the Montagne Noire reference section. The nature of the controls on the influx of iron into the marine system produces a natural hierarchy of at least seven orders or magnetozones designated MSZ1, MSZ2, MSZ3, MSZ4, MSZ5, MSZ6, and MSZ7. These are characterized in terms of the magnitude of their duration. The MSS reference section of choice for the F-F boundary is the well-known Trench C at La Serre (LSC) in the northeastern Montagne Noire of southern France. The F-F boundary lies at the base of MSZ La Serre Ialpha 3 (sub b) at La Serre, and magnetozones MSZ4 and MSZ5 at LSC are used to establish correlation between France and Oklahoma and to establish the position of the F-F boundary in the Oklahoma sections.