Multi-probe analysis for the definition of chemical and physical properties of the medieval frescoes of Santa Maria di Cerrate

Abstract

The complementary use of several diagnostic techniques allows a wide-ranging characterisation of a material and its chemical and physical properties, crossing information of its composition through qualitative and semi-quantitative analyses with the investigation of the crystalline components and the vibrational modes of its molecules. Moreover, studies of macro and micro-imaging can give a morphological description of the evaluated material, viewed both on surface and in cross section. A multi-analytical research carried out at the laboratories of the Center of Applied Physics, Dating and Diagnostics (CEDAD) of the University of Salento using Scanning Electron Microscopy (SEM-EDX), X-ray Diffraction (XRD), Raman Spectroscopy and Radiocarbon Dating by Accelerator Mass Spectrometry (AMS) permitted a deep and complete study on some samples of mortars, pigments, vegetal remains and degradation products from the frescos in the church of Santa Maria di Cerrate (Lecce), during the restoration work promoted by the FAI foundation (FondoAmbienteItaliano), giving a relevant contribution. In fact, in the field of conservation of Cultural Heritage, the physical-chemical characterization of the materials allows to gain fundamental information about both their degradation and the manufacturing techniques used by the artists, helping conservators in the actions of cleaning, consolidation and integration.