Lower Pliocene polarity transitions from the Suva Marl, Fiji

We present a paleomagnetic record of the lower Cochiti polarity transition and new results from the lower and upper Nunivak transitions obtained from the Lower Pliocene Suva Marl ( Fiji, (18°S, 178°E)). This formation has yielded a well‐defined magnetostratigraphy that, combined with 40Ar/39Ar ages from interbedded tuff beds, provides excellent chronostratigraphic control [Clement et al, 1997]. We previously presented the upper Cochiti and the upper and lower Nunivak polarity transition records from this unit [Clement et al., 1995, 1996]. New results were obtained from oriented block samples spanning these reversals. Each of these reversals was sampled at duplicate sections separated by 4 to 8 km. The agreement between the records obtained from different sections suggests that the paleomagnetic records are not artifacts of local sedimentary disturbances or random degrees of incompletely removed overprints. Instead the similarities in these and other records of these same reversals from different types of paleomagnetic recorders suggest that they provide information about the behavior of the geomagnetic field as it reverses.