Abstract:

The archaeological site of Can Tacó (Barcelona, Spain) is amilitary settlement which was strategically built on a small hill next to the old Via Augusta Roman road. The castellumwas erected sometime in early Roman times (second century B.C) and was demolished a century later. Among the numerous finds, the well preserved remains of a first Pompeian style painting stand out. This decoration, that imitates a free-stone wallwithmarble plates outlined by thin red lines, is considered of being one of the earliest Roman paintings recorded in the northeast of the Iberian Peninsula (modern Catalonia).The study of the mortars and stucco related to this parietal decoration will enable us to understand the technology used by Romans to build this sort of elements in such an early date. Themethods selected for the characterization of the painted layerswere Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF), X-ray Diffraction (XRD) and Scanning Electron Microscopy equipped with Energy Dispersive X-ray analysis system (SEM-EDS). According to the obtained results, the presence of the highly prized cinnabarí red pigment (HgS) has been detected,which sometimes appearmixedwith a lowamount of haematites (Fe2O3). Polarized Optical Microscopy (POM) and SEM-EDS were used to study the supporting materials. The results showed an extremely high quality lime mortar, with small grain size, well selected components (composed by crushed grains of calcite (CaCO3) which were intentionally added) and a component ratio of about 1:3 (one part of chalk and tree parts of sand). It has also been recorded the presence of superimposed layers (mortar and preparation layers) of different grain size.