Laboratory for Paleomagnetism and Physicochemical Properties of Rocks
As the result of prolonged field and laboratory studies carried out on a huge number of sections of different geological age, a behaviour of the ancient geomagnetic field for the past 400 billions years is obtained. The data comprised a basis of the global paleointensity database, complied by members of the laboratory in collaboration with French colleagues under umbrella of the International Association on a Geomagnetism and Aeronomy. Large volume and excellence quality of the data obtained allowed us to speak out a new scenario of global long-term evolution of the Earth's magnetic moment in the Phanerozoic. In the theory of geodynamo principles of a separation of a main part of the geomagnetic field into a quasistationary (characteristic time period is about 1 billion years) and a small in amplitude oscillating (characteristic time period is 1-10 thousands years) components, is obtained.
In the field of rock magnetism the international recognition was given to the so-called thermomagnetic criterion by Bol'shakov-Shcherbakova of determination of a domain structure of ferrimagnetic grains of rocks.
For the purposes of an evaluation of reliability of paleomagnetic data, a considerable attention is given to study of transformations of ferrimagnetics at the postcrystallized period. The data obtained allow us to evaluate quantitatively a stability of titanomagnetites (constituting the main body of ferrimagnetic minerals in igneous rocks) to the oxidation and the disintegration at the Earth's surface conditions.