The opus tessellatum of the St. Nicola’s Basilica (Bari, Italy): floor digital survey and marble tesserae characterization

The marble floor of the presbytery of St. Nicola’s basilica (Bari, Italy) is one of the few survivor evidences of this mosaic type of Byzantine period in the Apulia region. In virtue of the significant variability of employed stones, it could be considered as an interesting atlas for the field researches, in order to characterize the materials and to define their provenance. A multidisciplinary approach, including architecture, archaeology, petrography and art history expertise, together with the photogrammetric method, produced very useful results to disclose, preserve and valorise the ancient and the more recent marbles used in its tesserae and its artistic technique and to highlight the relationship between these last with the basilica historical events.