3. Results

Figure 1

[14]  The behavior of the Barremian-Cenomanian paleointensity is shown in Figure 1. In each magnetopolar interval studied there are burst-like and relatively quiet regimes of the geomagnetic field generation. Depending on the character of paleointensity variations, one can reveal several types of periodicity in its behavior.

[15]  1. Under quiet regimes of the magnetic field generation, short-time (with the duration from a few tens to a few hundreds millennia) variations of the field intensity are observed. The amplitude of paleointensity variations usually did not exceed 0.5  H₀. This type of variations is most distinctly pronounced in the lower and middle Cenomanian.

[16]  2. The change of geomagnetic field generation regimes took place in all fragments of the Cretaceous paleointensity. In the majority of cases the burst-like regime of the geomagnetic field generation was observed in the middle parts of polar intervals. The existence duration of these regimes was from a half to a quarter of the magnetopolar epoch duration (from a few hundreds to a million years).

[17]  3. It is worth noting a periodicity of paleointensity bursts repetition. The paleointensity values during the bursts were reaching 3  H₀. Since not more than one burst of the terrestrial magnetic field intensity was observed in each polar interval, their recurrence frequency should be of the order of millions years.

[18]  The mean values of the geomagnetic field intensity under quiet regimes of its generation differ depending on the magnetopolar interval studied or even parts of the same interval. The maximum mean values of the paleointensity of 0.8  H₀ were detected in the lower Albian and upper Aptian. The minimum values of the mean paleointensity of 0.5  H₀ were obtained for the lower Cenomanian, lower Aptian and the upper part of the upper Barremian. The mean value of the paleointensity over the entire time interval studied was 0.8  H₀.