La Situla della Certosa: studio diagnostico finalizzato alla protezione e conservazione

The recent discoveries of Etruscan remains in the northern regions of the Apennine, led to many discussions about the role of Bologna in the expansion of Etruscan influence in the northern Italy and have shed new light on one of the most representative pieces of the area, the Certosa Situla, known as the "queen" of situlae [1]. This Situla is, in fact, one of the most characteristic and important bronze artefacts of the Etruscan world. It was found in the Certosa Etruscan Necropolis (Bologna), in the cremation tomb n° 68 and it served as an ossuary. For a long time the grave context made it necessary to accept a dating for the Situla between the late sixth and the early fifth centuries BC, but many studies recognized the period of manufacture of the Situla to be about twenty years earlier than the date of burial. In occasion of the complete restoration of this famous bronze work, metallographic and chemical analyses have been carried out, in order to acquire elements about the bronze alloy, the manufacturing technology and the corrosion phenomena. Very small samples were accurately drawn from the upper side, from the centre, and from the bottom of the Situla; microstructural analyses have been carried out by optical microscopy (OM) and scanning electron microscopy (SEM), equipped with an energy dispersive spectroscopy system (EDS) for localized microanalyses. Chemical analyses by flame atomic absorption spectroscopy (FAAS) and X-ray diffraction (XRD) on patinas have been also carried out. The microstructural characteristics of the Certosa Situla have been eventually compared with the results obtained on other Etruscan situlae.