Stochastic behavior of geomagnetic field in the Middle Jurassic-Paleogene.

The distribution of the paleointensities and the lengths of geomagnetic polarity intervals (time intervals between the successive reversals of the Earth's magnetic field) corresponding to the different geological epochs was studied. It was found that the stochastic series of paleointensities in most cases are best approximated by the power-law function. The exponents of the power-law distributions vary depending on the intervals of the geological time that accommodate the analyzed paleomagnetic data. The distributions of the lengths of polarity intervals are approximated by the exponential function. The exponents varied depending also on the intervals of the geological time. The analysis shows that the most significant changes in the behavior of paleointensity occurred in the Paleogene near the Paleocene-Eocene boundary. Based on the analysis of the paleomagnetic data, it is hypothesized that turbulence of the magnetoactive medium played an important role in the generation of the Earth's magnetic field. The turbulence of the magnetoactive medium increased in the Cretaceous compared to the Jurassic and Paleogene. [ABSTRACT FROM AUTHOR]