PHYSICOCHEMICAL ANALYSIS OF ORIGINAL AND RESTORED CARBONATE MATERIAL OF THE ROMANIC CHURCH BELL TOWER IN LONGOBUCCO (CALABRIA, ITALY)

Abstract

The purpose of this paper is the comparison between the original and restored carbonate material of the bell tower of the Church Matrix in the Longobucco village (Calabria, Italy), built in Romanic style during the XII or XIII century. The characterization of the original and restored material was performed through micromorphological, pet-rographic and geochemical approaches utilizing optical and electron microscopy (SEM) observations, X-ray diffraction (XRD), X-ray fluorescence (XRF), mercury porosimetry, and Energy Dispersive Spectroscopy (EDS) analysis. Both materials are composed of low-magnesium calcite with siliciclastic inclusions, more abundant in calcarenites. The main differences are linked to the texture of the two rocks. The very porous continental calcareous tufa is made up of microbialitic boundstones with stromatolitic and thrombolytic-like microfacies. The marine calcarenite is composed of bioclastic grain stones and has a low porosity. The study shows the importance of the micromorphological and geochemical approach for the characteriza-tion of the physical-chemical properties of carbonate materials utilized in restoration and suggest that, for any restoration, the monument and territory history, but also the deeply knowledge of the material is deemed necessary.