A Discussion of Thermal and Alternating Field Demagnetization Methods in the Estimation of Paleomagnetic Field Intensities

Abstract

A brief discussion is given of the thermal and alternating field demagnetization methods in estimating paleomagnetic field intensities. It appears that reliable paleomagnetic intensity estimates may be obtained by alternating field demagnetization if (1) the results can be successfully extrapolated towards the highest microcoercivities of the NRM and of the TRM, and (2) the saturation magnetization has not changed appreciably after heating the sample to the Curie temperature and subsequent cooling. This would imply that the application of the “complete alternating field method” is not necessarily less laborious than that of the thermal method for which thermomagnetic analyses probably are not essential. © 1969, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.