PALEOMAGNETISM OF THE POINT ARENA TERRANE WITH INCLINATION FLATTENING CORRECTION AND IMPLICATIONS FOR TERRANE TRANSPORT
A paleomagnetic study of the German Rancho Formation within the Point Arena terrane is in progress to determine the amount of post-Eocene displacement. Preliminary results confirm previous paleomagnetic data reported by Kanter (1983). Both normal and reversed polarity characteristic directions are present and are antipodal. Our results will then be applied to determine the amount of compaction shallowing. Numerous studies have been completed that evaluate the effect of compaction on inclinations (Jackson et al., 1991; Kodama and Davi, 1995; Kodama and Ward, 2001). These methods utilize either anisotropy of magnetic susceptibility (AMS) or anisotropy of anhysteretic remanent magnetization (A-ARM) to determine the compaction-related mineral fabric in sedimentary rocks. Correlations between magnetic fabrics (AMS and A-ARM) and paleomagnetic inclinations are then used to evaluate, and possibly correct for, the occurrence of significant compaction flattening. For these rocks, these data will be used to directly test the hypothesis of Dickinson and Butler (1998), that attributes the shallow remanence inclinations entirely to compaction-flattening processes.