Archaeomagnetic versus luminescence methods: the case of an Early Byzantine ceramic workshop in Thessaloniki,Greece

In this contribution, we present a combined archaeomagnetic and luminescence study of archaeologically dated structures. The investigated area is a ceramic workshop comprising several Early Byzantine kilns. Based on (a) the archaeological–anthropogenic stratigraphy of the site, (b) the structural characteristics of the kilns and (c) the few ceramic findings revealed within their context, the operation of this brick and tile factory is approximately dated between the middle of the fifth century until the first decades of the sixth century AD. Three of the well-preserved workshop kilns have been studied archaeomagnetically. The full vector of the geomagnetic field, accompanied by rock magnetic analyses of the studied material, has been defined. The archaeomagnetic study revealed similar directions among the three kilns indicating and confirming their contemporary use. Additionally, several luminescence measurements were obtained on material from the same kilns. The dating of the site was performed with both methods. The archaeomagnetic dating is convergent with the archaeological estimation only when its upper limit is considered. Concerning the luminescence dating, the calculated ages (corrected for anomalous fading and for the ⁴⁰K content) with their standard deviations are convergent with the archaeological estimations for the first kiln, while for the other two, the results seem to be incompatible. The possible factors that provoked this divergence are thoroughly discussed.