Estimating properties of the paleomagnetic field from Icelandic lavas

The present paper uses (partially new) experimental data from 1 to 15 M.y. old lava sequences in Iceland to study the following three long-term statistical aspects of the paleomagnetic field. (I) The symmetry of various properties of the paleomagnetic field during this period, with respect to the polarity of the field. The available data from Iceland do not contradict the assumption that normal and reverse fields are similar in the long run. (II) The significance of statistical parameter values derived from observed paleomagnetic virtual-pole distributions. It is concluded that rather inadequate estimates of the mean pole position and its secular variation are obtained by averaging only 20 lava units, especially if some serial correlation is present. (III) Changes with time in the scatter of virtual-pole positions. Results strengthen previous conclusions that a reduction in this scatter at the latitude of Iceland has occurred during the period from 15 to 1 M.y. ago.