The relationship between the magnitude and direction of the geomagnetic field during the Late Tertiary in Eastern Iceland

• Published in: Geophysical Journal International
• Main Authors: Roberts, Neil, Shaw, John
• Format: Text
• Language: English
• Published: Oxford University Press 1984
• Subjects: Articles; Iceland
• Online Access: http://gji.oxfordjournals.org/cgi/content/short/76/3/637; https://doi.org/10.1111/j.1365-246X.1984.tb01913.x

During the Late Tertiary well over 1000 lavas were extruded in Eastern Iceland; potentially they each record an instantaneous description of the palaeomagnetic field. We have systematically attempted to determine the palaeofield magnitude from one specimen from each lava. About one in every four studied has yielded a palaeomagnitude value to go with the palaeofield direction value previously obtained. There is a slight preference for reversely magnetized specimens to yield results. Results from 106 lavas indicate an arithmetic mean value for the virtual dipole moment (VDM) of 8.2 × 0.5 × 1022 Am2. The data suggest an asymmetry whereby the normal polarity field was maintained in magnitude over a wider range of directions than was the reversed polarity field; possibly indicating its greater stability.