Two ancient Roman quarries in Cagliari (Italy): survey, mapping and evaluation of the state of conservation.

In several ancient Roman settlements of Sardinia, the presence of stone quarries is well known: although detailed studies on this field are still scarce, new acquisitions from various localities in Southern Sardinia allowed to achieve more information about the processes of stone extraction and working during the Roman age. The most relevant evidences are located in the urban area of Cagliari, characterized by diffuse occurrence of ancient quarries which testify a persistence in the use of the stone from Punic times to the Contemporary age. The dominant lithotypes historically quarried and used in the area are those of the Miocene sequence of Cagliari hills, which comprises, from bottom to the top, the “Pietra Cantone” marly limestone, the “Tramezzario” limestone and the “Pietra Forte” limestone. The Cagliari urban network has been the result of the merging of several historical minor settlements: the localization of the main extraction sites varied with time, depending from the materials requested during the development of these nuclei. In the Tuvu Mannu and Tuvixeddu hills, in which a pluri-secular activity of limestone extraction (in most part “pietra cantone” and “tramezzario”) for building stones, lime and concrete persisted up to 1960’s, several Roman quarry fronts recently exposed revealed a dense pattern of working traces, allowing to reconstruct different tools probably utilized for stone extraction. The quarry fronts, to be referred to the Ist – IInd centuries B.C., are part of an area of intensive exploitation of the limestone, where the more argillaceous/arenaceous “Pietra Cantone” and the “Tramezzario”were mostly used for small blocks, but also in the making of lime mortars, as testified by the presence, close to two quarry fronts, of two limekilns for lime production from crushed rocks, an important evidence of the introduction of this construction material in this epoch.