Variation séculaire de la direction du champ géomagnétique enregistrée par les laves de l'Etna et du Vésuve pendant les deux derniers millénaires

High precision methods of sampling and measurement developed at Saint-Maur laboratory added to a critical examination of written documents pertaining to the history of Etna and Vesuvius enable us to reconstruct the path of the geomagnetic field direction in southern Italy for the past 2 000 years. This curve agrees well with that obtained from archaeomagnetism in France and may confidently be used either for geophysical purposes or for dating high-temperature-emplaced volcanic products and archaeological structures in the time span considered.