Archaeomagnetism in Italy: a compilation of data including new results and a preliminary Italian secular variation curve

Abstract : Published Italian archaeomagnetic data are combined with new data from the Genève and Torino laboratories. A total of 74 directional data is presented with age estimates falling between 1300 BC to 1600 AD, including results from volcanic deposits of unquestionable age. The data set has been analysed using the Bayesian stochastic approach for curve building to produce a preliminary Italian secular variation (SV) curve. Comparison with the French SV curve shows a general agreement but some significant differences are also observed. The new Italian SV curve can be used for archaeomagnetic dating of Italian artefacts, even though caution must be paid for the period 9th­12th century AD and times older than 8th century BC, when only few data are available and error envelopes are large.