Petrographic Analysis of the Volcanic Component of Roman Mortars From the Early Imperial Age to the Renaissance in the Archeological Excavations at Mausoleum of Augustus

We present the results of the petrographic analysis on 11 thin sections representative of the mortars and concretes of ancient masonry structures ranging from the Augustan Age to the Renaissance, exposed from recent excavations carried out at the Mausoleum of Augustus in Rome, aimed at investigating the evolution of the materials employed as aggregates. Our study attests to the systematic and exclusive use of volcanic rocks in the production of fine aggregates for mortars and concretes in Rome from the second century bc to the sixteenth century ad . Even considering the limits of the analyzed dataset, the results provide a homogeneous and linear picture, outlining a first overview of the use and selection of volcanic materials that highlights the migration outside the city of the extraction areas, which is accompanied by a notable stability of the typology of materials used and of the construction techniques across two millennia.