EXTENSIVE GEOPHYSICAL INVESTIGATIONS TO STUDY THE ARCHAEOLOGICAL SITE OF NORBA (NORMA, CENTRAL ITALY)

This study is part of the "Norba Project", jointly developed between the University of Campania region "Luigi Vanvitelli", the Municipality of Norma (Latina) and the Institute of Technologies Applied to Cultural Heritage (ITABC-CNR). The archaeological site of Norba is located in the Latium Region, about 90 Km south of Rome, in Italy. The ancient town of Norba rises on a high plateau overlooking the Pontine plain. The city represents one of the best examples of urban town planning, with a regular layout dating back to an ancient age. During the last ten years, the site has undergone many studies, followed by archaeological excavations, which allowed several buildings and other important archaeological features to be brought to light. The conservation of the polygonal walls and other structures, has attracted to Norba, since the beginning of the eighteenth century, the attention of the historians and archaeologists; it has also been used for the experimentation of the first examples of aerophotogrammetric restitution. Thanks to the work of Latium Region and the Municipality of Norma, now the whole site is part of an archaeological Park. The archaeological excavations made in a small portion of the town allowed to recognize a regular urban layout, marked by terraces in polygonal work. The Project started in 2017 with new acquisition and processing of extensive geophysical surveys to investigate unexcavated portions of the archaeological site with the aim to enhance the knowledge of the urban plan of the ancient town. Ground Penetrating Radar and the Gradiometric methods have been applied to investigate this site. In particular, GPR system SIR 3000 (GSSI), equipped with a 400 MHz antenna with constant offset was employed to survey 18 different areas close to some of the unearthed structures. Furthermore, differential magnetic surveys were carried out using the Geoscan FM256 in few areas investigated with GPR. The results obtained from the geophysical surveys were interpreted together with the archaeologists to define the meaning of all the identified anomalies and to enhance the knowledge of the ancient town's layout and mapping.