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Effect of magnetic anisotropy on the experimentally determined palaeointensity of the geomagnetic field
Earth, Planets and Space volume 53, pages363–371(2001)
Rock magnetic properties of the Nile mud are reported. They indicate that the carrier of magnetization in the Nile mudis predominantly magnetite. Fourty air-dried ceramic samples made of Nile mud were manufactured to ceramics by stepwise heating to 700°C at various field intensities between 0.03 mT and 0.09 mT and with various angles θ between the laboratory field (FL) direction and the ceramics. The partial (pTRM) and the total thermoremanent magnetization (TRM) increase linearly as the magnetic field (FL) increases. The rate of increase of the pTRM with both FL and temperature T depends on θ, so that it decreases by 25% as θ increases from 0° to 90°. In extreme cases, the effect of the magnetic anisotropy results in overestimating the determined palaeointensity by 33% and underestimating it by 25% from the correct value. The direction of TRM is the same as that of the ambient magnetic field independent of the anisotropy. Applying the laboratory field in the direction of the stable natural remanent magnetization during a Thellier-type experiment results in accurate determination of the palaeointensity.
Ade-Hall, J. M., M. A. Khan, P. Dagley, and R. L. Wilson, A detailed opaque petrogical and magnetic investigation of a single Tertiary lava flow from Skye, Scotland-III: Investigations into the possibility of obtaining the intensity of the ambient magnetic field (Fanc) at the time of the cooling of the flow, Geophys. J. R. Astr. Soc, 16, 401–415, 1968.
Aitken, M. J., A. L. Allsop, G. D. Bussell, and M. B. Winter, Geomagnetic intensity variation during the last 4000 years, Phys. Earth Planet. Inter., 56, 49–58, 1989.
Banerjee, S. K. and J. Mellema, A new method for the determination of the palaeointensity from the ARM properties of rocks, Earth Planet. Sci. Lett., 23, 177–184, 1974.
Coe, R. S., The determination of palaeointensities of the Earth’s magnetic field with emphasis on mechanisms which could cause non-ideal behaviour in Thelliers’ method, J. Geomag. Geoelectr, 19, 157–179, 1967.
Coe, R. S. and S. C. Gromme, A comparison of three methods of determining the geomagnetic palaeointensities, J. Geomag. Geoelectr, 25, 415–435, 1973.
Day, R., M. Fuller, and V. A. Schmidt, Hysteresis properties of titanomagnetites: grain size and compositional dependences, Phys. Earth Planet. Inter, 13, 260–267, 1977.
Domen, H., A single heating method of palaeomagnetic field intensity determination applied to old roof tiles and rocks, Phys. Earth Planet. Inter, 13, 315–318, 1977. Fox, J. M. W. and M. J. Aitken, Cooling rate dependence of thermoremanent magnetization, Nature, 283, 462–463, 1980.
Heider, F., D. J. Dunlop, and N. Sugiura, Magnetic properties of hydrothermally recrystallized magnetite crystals, Science, 236, 1287–1290, 1987.
Hussain, A. G., The secular variation of the geomagnetic field in Egypt in the last 5000 years, Pure Appl. Geophys., 125, 67–90, 1987.
Kono, M., Reliability of palaeointensity method using alternating field demagnetization and anhystereticremanence, Geophys. J. R. Astr. Soc, 54, 241–261, 1978.
Kono, M., Changes in TRM and ARM in a basalt due to laboratory heating, Phys. Earth Planet. Inter, 46, 1–8, 1987.
Kono, M. and H. Tanaka, Analysis of the Thelliers’ method of palaeointensity determination 1: Estimation of statistical error, J. Geomag. Geoelectr, 36, 267–284, 1984.
Kono, M. and N. Ueno, Palaeointensity determination by a modified Thellier method, Phys. Earth Planet. Inter, 13, 305–314, 1977.
Nagata, T., The natural remanent magnetism of volcanic rocks and its relation to geomagnetic phenomena, Bull. Earthquake Res. Inst., Univ. Tokyo., 21, 1–196, 1943.
Odah, H., Palaeomagnetic and archaeomagnetic studies on some localities in A. R. Egypt, Ph.D. thesis, Mansoura University, 190 pp., Egypt, 1993.
Odah, H., F. Heider, A. Hussain, V. Hoffman, H. Soffel, and M. El Gamili, Palaeointensity of the geomagnetic field in Egypt from 4000 BC to 150 AD using the Thellier method, J. Geomag. Geoelectr, 47, 41–58, 1995.
Rigotti, P. A., The A.R.M. correction method of palaeointensity measurements, Earth Planet. Sci. Lett., 39, 417–426, 1978.
Rogers, J., J. M. W. Fox, and M. J. Aitken, Magnetic anisotropy in ancient pottery, Nature, 277, 644–646, 1979.
Schweitzer, C., Vergleich mehrerer Methoden zur Bestimmung der Intensitüt des Erdmagnetfeldes an rezenten Laven und ihre Anwendung auf mesozoische und palaozoische magmatische Gesteine, Dissertation Fachbereich Geowissensschaften, Ludwig Maximielein Universitat, München, 1975.
Senanayake, W., M. W. McElhinny, and P. McFadden, Comparison between the Thelliers’ and Shaw’s palaeointensity methods using basalts less than 5 million years old, J. Geomag. Geoelectr., 34, 141–161, 1982.
Shaw, J., A new method of determining the magnitude of the palaeomagnetic field. Application of five historic lavas and five archaeological samples, Geophys. J. R. Astr. Soc, 39, 133–144, 1974.
Tanaka, H. and M. Kono, Analysis of the Thellier’ method of palaeointensity determination 2: Application to high and low magnetic fields, J. Geomag. Geoelectr, 36, 285–297, 1984.
Thellier, E., Early research on the intensity of the ancient geomagnetic field, Phys. Earth Planet. Inter, 13, 241–244, 1977.
Thellier, E. and O. Thellier, Sur l’intensite du champ magnetique terrestre danslepassehistoriqueetgeologique, Ann. Geophys., 15,285-376,1959.
Walton, D., Improving the accuracy of the geomagnetic intensity measurements, Nature, 328, 789–791, 1987.
Walton, D. and H. Balhatchet, Application of a new technique to Greek archeomagnitudes, J. Geomag. Geoelectr, 40, 1503–1510, 1988.
Yang, S., J. Shaw, and Q. Y. Wei, A comparison of archaeintensity results from Chinese ceramics using Thellier and Shaw’s palaeointensity methods, Geophys. J. Int., 113, 499–508, 1993.
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Odah, H., Hussain, A.G., Hoffmann, V. et al. Effect of magnetic anisotropy on the experimentally determined palaeointensity of the geomagnetic field. Earth Planet Sp 53, 363–371 (2001). https://doi.org/10.1186/BF03352393
- Magnetic Anisotropy
- Magnetic Mineral
- Natural Remanent Magnetization
- Anhysteretic Remanent Magnetization