In the framework of a research program aimed to define the chronology of the structures of the architectonic complex of San Francesco alla Collina (Paternò, Italy), two luminescence dating techniques were applied: Thermoluminescence (TL) on terracotta bricks and Optically Stimulated Luminescence (OSL) on mortars.
Dating a historic building through the age of its bricks can be sometimes complex, for the possible gap between the age of the bricks themselves and that of the structure. Considering that the laying of mortar is contemporary to the construction, the principal objective of the work here presented is the verification of the possibility of solving chronological uncertainties of specific parts of a building using simultaneously TL on bricks and OSL on the associated mortar.
The dating of bricks was obtained using the polymineral 4-11 m granulometric fraction following the fine-grain technique. Starting from the same granulometric fraction, a new protocol consisting of different etching treatments, associated with a feldspar contamination test, was developed to obtain pure quartz grains from mortar.
The study shows the possibility of dating the mortar by luminescence, in particular using the OSL emissions of the fine-grained quartz fraction. The main focus is to provide a procedure where each step was opportunely adapted to mortar, starting from the chemical-physical preparation to the luminescence measurements protocols.
The good agreement of OSL dating of mortars and TL dating of associated bricks and the correspondence of these ages with the well documented historical phases, unique at this time, represents an important goal for application. It is possible to assert that luminescence techniques permit the resolution of dating problems regarding historical buildings above all in terms of dating back to the use of the bricks in the construction from the laying of mortars
