Conservation of a colosal statue of Zeus from Soluntum (Sicily, Italy): Scientific and historical remarks about previous restorations

V Conferencia Internacional YOCOCU (Youth in conservation of cultural heritage), Madrid, 21-23 de septiembre, 2016
During the first decades of 19th century, the Commission for the Antiquities and Fine Arts supervised many excavations and restorations in the major archaeological sites of Sicily, discovering many important finds around the island. Several of them belong to the archaeological collection of Museo Archeologico Regionale (Regional Archaeological Museum) ¿A. Salinas¿ of Palermo. One of the most important finds from this site is the colossal statue of Zeus enthroned, a pseudo acrolithic statue, dated to the 2nd century B.C. and it is one of the few examples of large size statue in Sicily. The statue was discovered in 1825 in the site of the ancient city of Soluntum that is certainly one of the main important archaeological sites in Sicily, not so far from the modern town of Palermo (Sicily). In 1826, the neoclassical sculptor Valerio Villareale restored the colossal statue of Zeus that was found in fragments, for completing the missing parts with stucco. At the beginning, the state of conservation did not allow to distinguish the original matter from that one of the Villareale completing. The recent conservation gave the opportunity to investigate and to study the statue during each of the stages of the work. Thanks to a scientific approach, it was possible to investigate the history and to respect the original matter. The conservative activities were aimed to investigate also the restoration matter as a fundamental requirement for a suitable conservation. Several chemical and structural diagnostic analyses were carried out, both in situ and in laboratory, to deepen into the knowledge of restoration materials, their degradation state and the overlapping with the original surface. In particular, the Ultraviolet Induced Fluorescence imaging, Infrared termography, cover meter relief, X-Ray Fluorescence analysis, UV and Vis optical microscope were carried out in situ to mapping the different materials and to understand the junction method between the original parts and the restoration ones. Supported by the preliminary in situ information, the sampling was realized to deepen into the elemental and compositional characterization of the material used for each restoration stage documented over time. With this aim, optical microscopy (stereomicroscopy and polarizing optical microscopy) scanning electron microscopy (SEM-EDS), FTIR-RAMAN spectroscopy and cross section UV light acquisition were carried out. The analytical results have given precious information to suggest the historical research for a better knowledge of the conservative history of the statue. This work permitted to increase the knowledge about the restoration process during the neoclassical period, in which it was fixed the basis for the modern process of conservation.