© Società Geologica Italiana, Roma 2017
CONGRESSO SIMP-SGI-SOGEI-AIV 2017
Villa del Capo and Villa del Pezzolo: Roman mortars from Sorrento Peninsula Rispoli C.*1, Guarino V.1, De Bonis A.1, Di Benedetto C.1, Esposito R.2, Graziano S.F.1, Morra V.1 & Cappelletti P.1 1
Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università "Federico II", Napoli 2 Dipartimento di Studi Umanistici, Università "Federico II", Napoli
* Corresponding email:
[email protected] Keywords: ancient Roman mortars, Sorrento Peninsula, Villa del Capo, Villa del Pezzolo.
This study concern the characterization of ancient Roman mortars present in Villa del Capo (commonly called Bagni della Regina Giovanna) and Villa del Pezzolo in Sorrento Peninsula. Different materials (bedding, coating and floor mortars) were collected in the two villas. Mortar characterization was carried out through optical microscopy (OM) on thin sections, X-ray powder diffraction (XRPD), scanning electron microscopy analysis (SEM), energy-dispersion Xray spectroscopy (EDS), thermal analyses (TGA-DTA) and mercury intrusion porosimetry (MIP). Bedding mortars were realized using a mixture of slaked lime, water, fine-grained volcanic materials with addition of a coarse grained volcanic and carbonatic aggregates; as coating and floor mortars are concerned, the previous described mix design presents also fragments of (fine- and coarse-grained) ceramic materials. The provenance of lime and carbonate fragments, identified in the villas, is still unknown, probably they could have been produced on site using local raw materials, widely present in the Sorrento Peninsula. More interesting are the differences in the provenance and mixture of volcanic aggregates identified in the Villa del Capo and Villa del Pezzolo mortars. Villa del Capo mortars show volcanic aggregates related to the Neapolitan Yellow Tuff formation, due to the peculiar mineralogical association (phillipsite > chabazite > analcime) (de Gennaro et al., 2000). Occurrence of leucitebearing scoriae and garnet crystals, typical of volcanic deposits related to the Somma-Vesuvius activity, are also present in some samples from Villa del Capo. Mortars from Villa del Pezzolo belong to three distinct building phases. Volcanic tuff fragments in mortars of the 1st building phase could be assigned to the Campanian Ignimbrite formation, cropping out widely in Sorrento Peninsula. This was confirmed by the presence of glassy shards, partially devitrified and replaced by authigenic feldspar, a typical feature of welded gray Campanian Ignimbrite lithofacies (WGI; Langella et al., 2013). The volcanic aggregates in samples of the 2nd and 3rd building phases show instead presence of leucite-bearing volcanic scoriae and garnet crystals, thus suggesting use of a volcanic aggregates influenced by Somma-Vesuvius eruptions. de Gennaro M., Cappelletti, P., Langella, A., Scarpati, C. (2000): Genesis of zeolites in the Neapolitan Yellow Tuff: geological, volcanological and mineralogical evidence. Contrib. Mineral. Petrol., 139, 17-35. Langella, A., Bish, D.L., Cappelletti, P., Cerri, G., Colella, A., de Gennaro, R., Graziano, S.F., Perrotta, A., Scarpati, C., de Gennaro, M. (2013): New insights into the mineralogical facies distribution of Campanian Ignimbrite, a relevant Italian industrial material. Appl. Clay Sci., 72, 55-73.
192
