THE SCIENTIFIC SUPPORT OF A PRESERVATION WORK - THE FRESCOES IN THE AOSTA CATHEDRAL UPPER NAVE, FROM THE DIAGNOSTIC RESEARCH TO THE COMPLETED RESTORATION

In the field of preservation the opinion has been spreading that is ne cessary to promote more and more contact between humanistic and scient ific sectors. After all, this kind of intervention concerns the study of materials and, therefore, it requires a rich store of knowledge tha t must get rid of the ''trade secrets'' empirism, which is typical ins ide the handicraft environment. An example of benefit resulting from s ynergy between humanistic and scientific fields is given by the interv ention in the restoration and rediscovery of the loft frescoes in the Cathedral of Aosta, which belong to the Ottonian period (XI century). The planning of recovery intervention has required scientific understa nding which was able to fill the gaps in our knowledge, regarding both historical-artistic and preservation interests. Analytical applicatio ns have availed themselves of various technologies aimed at the charac terisation of the materials. The study has been led with the help of X -ray diffraction, ion chromatography, infrared spectrophotometry and o ptical microscopy. The use of histochemical and immunological techniqu es has enabled the quantitative characterisation of binding materials/ alloying elements.