Characterisation of archaeological mortars and plasters from Kyme (Turkey)

The present study focuses on the compositional characterisation of Roman, proto-Byzantine and Medieval mortars, sampled in the archaeological site of Kyme (Turkey), an Aeolian city, founded in the middle of the XI century BC by Greek populations. The mortars were studied through elemental (SEM-EDS, XRF), mineralogical (XRPD, De Astis calcimeter) and petrographic (polarised optical microscopy) analysis. The comparison between the samples allowed us to emphasise compositional differences within mortars of the same historical period. In particular, we detected the prevalent use of cocciopesto, which was used as a pozzolanic additive to create hydraulic mortars in the Roman and Byzantine period. The cocciopesto was used to improve the technological properties of an initially slaked lime. Furthermore, compositional similarities allowed us to attribute an unknown sample to the Roman period. Our study also pointed out the fact that the lower quality mortars belonged to the Medieval period. As a matter of fact, the most friable sample belonging to the Middle Ages turned out to be a mixture of clay, lime and volcanic sand