Geomagnetic polarity changes and the duration of volcanism in successive lava flows

Analysis of observational data on active volcanoes of the world shows that eruptions of lavas from a volcano may be considered as events in a simple Poisson process. It has been shown by Cox that in the Cenozoic the geomagnetic field reversed its polarity in a random manner and the polarity intervals follow an exponential distribution. By combining the knowledge of statistical properties of these two mutually independent phenomena, it is possible to predict the time that elapsed in the formation of a paleomagnetically studied sequence such as successive lava flows. Statistical arguments are extended, and 95% and 99% confidence limits are calculated for the time interval of such sequences. This method makes it possible to estimate intervals covered by certain lava sequences formed in the Cenozoic without going into detailed absolute age studies.