Author: Present

Specialty: 010700/07 Earth Physics
Program: Physics
Head of the program: prof. V. N. Troyan
Department of the Earth Physics
Scientific adviser: E. S. Sergienko
Reviewer: assoc.. I. N. Petrov

Checking a possibility of applying stepwise remagnetization method 
to rocks having thermal remanence
A. V. Sapozhnikov

A device to conduct stepwise remagnetization by alternating field was constructed and calibrated. Stepwise remagnetization in a wide range of magnetic fields was applied to a number of thermally magnetized natural and model samples having different genesis and age.
Characteristic inhomogeneities in magnetic structures were distinguished and an estimate of palaeointensity was provided. Two methods of data processing were used including statistical analysis and a value of remanence on the fifth step. Also two suggestions about increasing resolution of stepwise remagnetization method were given.
On the results of the work the following conclusions were made.
1.	Characteristic features in magnetic structure of rocks with thermoremanence can be found on stepwise remagnetization curves.
2.	Secondary remagnetization can be a reason for having two inhomogenities at the single stepwise remagnetization curve.
3.	Application of an alternating field may result in less dispersion on stepwise remagnetization curve and showing features more accurately.

The list of publications
1.	A. V. Sapoznikov, E. S. Sergienko, R. V. Smirnova, I. N. Petrov, A. A. Kosterov. Structure and phase transformations in magnetites from the Angaro-Ilim deposit // 
8th International Conference “Problems of geocosmos”. St. Petersburg. 2010.
2.	E. S. Sergienko, R. V. Smirnova, E. S. Drabkina, A. B. Pronevich, A. V. Sapozhnikov. Structural changes in natural ferrimagnetics forming specific magnetic states of rocks //  Proceedings of the second international conference «Priorities in science investigations of natural and artificial nano-size objects ». Saint-Petersburg. 2011. Pp. 77-79.
3.	E. S. Sergienko, A. V. Sapozhnikov, I. N. Petrov. Microstructure and magnetic features of ferrimagnetic minerals from Angaro-Ilimskoe ore // Problems of Geophysics. Vol. 44. Published in St.-Petersburg Saint University. St.-Petersburg. 2011. Pp. 172-178.
4.	A. V. Sapozhnikov, E A. Drabkina, V. V. Popov, E. S. Sergienko, R. V. Smirnova. Using non-heat methods to estimate the value of ancient geomagnetic field (using impacts of Kara astroblem). // Theses of BOROK seminar. GO Borok. 2011. Pp. 205-211.