Archaeomagnetic evidence for the age of a Roman pottery kiln from Calahorra (Spain)

Abstract

The first report of a palaeomagnetic study of a Roman pottery kiln is presented. Individual bricks from the walls of the heating chamber have been sampled and measured in order to determine their palaeomagnetic directions. The measurements indicate that the innermost part of the structure was heated well above the Curie point of haematite, enabling the use of the palaeomagnetic declination and inclination, after the axial dipole correction and fitting to the Paris Z ( t ) curve, to infer the age of the last heating event.

A new contribution to the archaeomagnetic study of a Roman pottery kiln from Calahorra (Spain)

“…Their field numbers ( Fig. 1) correspond to those of the previous paper (Pares et al 1992). By using the Thellier method, one can distinguish 'different attitudes of the samples with respect to the central furnace' (Pares et al 1992, p. 534).…”

“…Since such curves are not yet available for Spain, the dating in Pares et al (1992) was made using the secular variation curve for Paris. The pottery kiln was shown to belong to the middle or to the second part of the 1st century AD.…”

“…The Pares et al (1992) estimation of the ancient geomagnetic field direction using the same collection of samples is D=359.2", Z=58.4", cl,,=2.1".…”

“…The first report of an archaeomagnetic study of a Roman pottery kiln from Spain was published by Pares et al (1992), in which only directional results obtained from the pottery kiln's heating chamber were presented. A successful dating was performed in the above-mentioned paper on the basis of the inclination secular variation reference curve for Paris (Langouet, Bucur & Goulpeau 1983).…”

Recent achievements in archaeomagnetic dating in the Iberian Peninsula: application to Roman and Mediaeval Spanish structures

“…New studies have increased the amount of data and it is now possible to retrace the evolution of the geomagnetic field direction in this region for at least the past two millennia. Gómez-Paccard et al (2006a) presented a compilation of previously available archaeomagnetic directions for Spain (Thellier, 1981;Parés et al, 1992;Oyamburu et al, 1996) along with the results from 58 structures not studied previously, providing a catalogue of 63 archaeomagnetic directions spanning the last two millennia. In order to construct the SV curve for Iberia, Gómez-Paccard et al (2006b) compiled a data set of archaeomagnetic directions from sites that fell within a 900 km circle centred on Madrid.…”