Comment on ‘‘Recent eruptive history of Stromboli (Aeolian Islands, Italy) determined from high-accuracy archeomagnetic dating’’ by S. Arrighi et al.

Abstract

Arrighi et al. [2004] (hereinafter referred to as AR2004) recently reported paleomagnetic directions gathered from Stromboli volcano by using the unconventional "large sample method" (LSM). These directions are partly different and have smaller confidence cones than those previously reported by Speranza et al. [2004] (hereinafter referred to as SP2004) for the same spatter lavas by using the traditional (core-drilling and systematic stepwise demagnetization) paleomagnetic technique. Hence AR2004 conclude that "traditional paleomagnetic sampling cannot yield sufficient precision", and is therefore unsuitable to study the paleosecular variation of the geomagnetic field recorded in volcanics, and to use it as a dating tool. Here we contend that the laboratory procedures and analysis methods employed by AR2004 yield a fictitious improvement in statistical uncertainty. We conclude that the traditional paleomagnetic techniques provide a more realistic estimate of archeomagnetic dating and related uncertainties.