Archaeomagnetic study of a limekiln in the Les Ferreres Roman aqueduct, World Heritage Site of Tarraco

Abstract

The aqueduct of Les Ferreres is a major element of the Archaeological Ensemble of Tarraco. Although the ashlars of the aqueduct are stacked without mortar, lime was used in some parts and lime was certainly used in later repairs. Worthy of note is a coating mortar used in a well-documented restoration (1854–1856). In this study, a limekiln found near the Roman aqueduct has been archaeomagnetically dated to determine if it was used for the construction of the aqueduct or in later repairs. The mean values for the measured archaeomagnetic direction from the limekiln were compared with two different archaeomagnetic models (SCHA.DIF.3k and GUMF1), and both indicate that the limekiln is modern with ages only slightly older than the well-documented restoration. The extensive use of the coating mortar in that restoration is consistent with the need of onsite lime production. Additional archaeomagnetic intensity has not contributed to constrain further the obtained archaeomagnetic age but the intensity datum can be added to archaeomagnetic intensity datasets to enhance geomagnetic intensity field models. The paper illustrates how archaeomagnetic dating can be useful to characterize secondary structures of major cultural heritage monuments. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.