A new quality check for absolute palaeointensities of the Earth magnetic field

Absolute palaeointensity determinations of recent lavas from Mt. Etna have been carried out using the Koenigsberger‐Thellier‐Thellier (KTT) method but with two different data presentations. The first, which is the standard method, compares the natural remanent magnetization (NRM) demagnetized and the thermoremanent magnetization (TRM) acquired in successive temperature intervals cumulatively. The second compares the NRM and TRM in the successive intervals in an incremental manner. The latter method appears to distinguish aberrant behaviour better than the classical method. Such aberrant behaviour can be related to changes in hysteresis ratio parameters, saturation remanent magnetization to saturation magnetization and remanent coercive force to coercive force, which are reflected by displacements in the Day et al. (1977) plot. These changes in hysteresis parameters are caused by irreversible changes in domain state or transformations of magnetic phases brought about by the thermal cycling. The changes in hysteresis parameters serve as a useful quality factor for absolute palaeointensity determinations.