Complete and partial self-reversal of natural remanent magnetization of basaltic rocks from Lower Silesia, Poland
Experiments of heating-cooling cycles in zero magnetic field were performed in order to study self-reversal of NRM in basaltic rocks from Lower Silesia. Complete self-reversal occurred in one sample containing titanomagnetite withTc of 170°C and a small amount of a phase with higher Curie point. During consecutive heat treatments the phenomenon became less conspicuous. In three samples of higher oxidation level, containing several magnetic phases, only partial self-reversal of NRM occurred. For the most oxidized sample no changes of direction of NRM were observed. We suggest that the investigated phenomenon of self-reversal of NRM is due to a negative magnetic interaction between primary titanomagnetite and products of its oxidation. It seems that complete self-reversal can take place in a restricted state of oxidation.
KeywordsOxidation Magnetic Field Heat Treatment Remanent Magnetization Magnetic Phasis
Unable to display preview. Download preview PDF.
- K. Birkenmajer, M. Jeleńska, M. Kądziaŀko-Hofmokl, J. Kruczyk andJ. Siemiątkowski,Palaeomagnetism and magnetic properties of Tertiary basaltic rocks from Góra św. Anny and Ligota Tulowicka, Acta Geol. Pol. to be published.Google Scholar
- K. M. Creer andN. Petersen,Thermochemical magnetization in basalts, Zeitschrift für Geophysik,B 35 (1969), 501.Google Scholar
- K. M. Creer, N. Petersen andJ. Petherbridge,Partial self-reversal of remanent magnetization and anisotropy of viscous magnetization in basalts, Geophys. J.21 (1970), 471.Google Scholar
- H. Hashimoto, A. Kumao, K. Hino, H. Yotsumoto andA. Ono,Observations of atoms by conventional electron microscopy, Jeol News vol.9e, N 3 (1971) 3.Google Scholar
- N. Petersen andU. Bleil,Self reversal of remanent magnetization in synthetic titanomagnetites, Zeitschrift für GeophysikB 39 (1973), 965.Google Scholar
- A. Schult,On the strength of exchange interactions in titanomagnetites and its relation to selfreversal of magnetization, Zeitschrif für Geophysik,B 37 (1971), 357.Google Scholar