A comparison of the statistical secular variation recorded in some late Quaternary lava flows and sediments, and its implications

Abstract

Paleomagnetic results from late Quaternary sequences of lava flows, wet sediments, and dry sediments are used to investigate the long-term statistical behavior of the Earth's magnetic-field secular variation. Two statistical parameters, ΔI anomaly (average site inclination minus expected site axial-dipole inclination) and virtual-geomagnetic-pole angular dispersion, are estimated from these data sets. Internal comparison of the late Quaternary statistical results indicates that the lava flows, wet sediments, and dry sediments all yield high quality statistics, and that there is no systematic "inclination error" associated with either the wet or dry sediment data. Comparison of the late Quaternary statistical results with similar statistical estimates for the last 5 million years, on average, indicates that the late Quaternary global pattern of ΔI anomaly is unchanged (self-stationary) from its 5-million-year average, but that the late Quaternary global pattern of angular dispersion is significantly different (nonstationary) from its 5-million-year average.