  The results of paleointensity determinations of the geomagnetic field, which
are obtained by sedimentary rocks in the Middle Jurassic - Neogene (167-12) Ma,
are summarized. It was found that in the interval (167-67) Ma (Middle Jurassic
- Cretaceous) mean values and amplitudes of paleointensity variations
increased. Mean values of paleointensity reached a maximum in front of the
Cretaceous-Paleogene boundary. During the Paleogene the mean values and
amplitudes of paleointensity variations decreased. In the Cretaceous - the
beginning of the Paleogene cyclic changes in the amplitudes of paleointensity
variations with characteristic times of several million years have been
observed. It is shown that the duration of cycles of the paleointensity changes
coincided with transgressive-regressive cycles (T-R cycles). This can be
considered as a confirmation of the hypothesis on a relation between processes
in the Earth's core and tectonic processes.
